Merge branch 'dev' into platformio-skip-private-probe

Co-authored-by: J. Nick Koston <nick@home-assistant.io>

.github/actions/cache-clang-tidy-idedata/action.yml

@@ -0,0 +1,50 @@
+name: Cache clang-tidy idedata
+description: >
+  Cache the clang-tidy idedata and the headers it references under .temp
+  (headers only, about 30MB per env). Run after restore-python and cache-esp-idf.
+inputs:
+  environment:
+    description: 'clang-tidy environment (e.g. esp32-idf-tidy).'
+    required: true
+runs:
+  using: composite
+  steps:
+    - name: Compute cache key
+      id: key
+      shell: bash
+      run: |
+        . venv/bin/activate
+        [ -n "${{ inputs.environment }}" ] || { echo "::error::cache-clang-tidy-idedata: 'environment' input is empty"; exit 1; }
+        hash=$(python -c 'import sys; sys.path.insert(0, "script"); from clang_tidy_hash import idedata_cache_hash; print(idedata_cache_hash("${{ inputs.environment }}"))')
+        pyver=$(python -c 'import platform; print(platform.python_version())')
+        # Generating idedata is what installs ESP-IDF; never skip it over a missing
+        # install. This also skips the save, so a dev run that installs ESP-IDF
+        # warms the idedata cache on the next run.
+        if [ -d ~/.esphome-idf/frameworks ]; then
+          echo "skip=false" >> "$GITHUB_OUTPUT"
+        else
+          echo "ESP-IDF install missing, not using the clang-tidy idedata cache"
+          echo "skip=true" >> "$GITHUB_OUTPUT"
+        fi
+        echo "key=${{ runner.os }}-tidy-idedata-${{ inputs.environment }}-$hash-py$pyver" >> "$GITHUB_OUTPUT"
+        {
+          echo "path<<EOF"
+          printf '%s\n' '.temp/idedata-*.json' '.temp/idedata-*.hash'
+          printf '.temp/**/*.%s\n' h hpp hh hxx inc inl ipp tpp
+          echo "EOF"
+        } >> "$GITHUB_OUTPUT"
+    # Mirror cache-esp-idf: write on dev, restore-only on PRs. The post-step
+    # save only runs when the job succeeded, so a failed generation is never saved.
+    # Extend the extension list if a component ships extensionless headers.
+    - name: Cache clang-tidy idedata (write on dev)
+      if: (github.ref == 'refs/heads/dev' || contains(github.event.pull_request.labels.*.name, 'ci-cache-write')) && steps.key.outputs.skip != 'true'
+      uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
+      with:
+        path: ${{ steps.key.outputs.path }}
+        key: ${{ steps.key.outputs.key }}
+    - name: Cache clang-tidy idedata (restore-only off dev)
+      if: github.ref != 'refs/heads/dev' && !contains(github.event.pull_request.labels.*.name, 'ci-cache-write') && steps.key.outputs.skip != 'true'
+      uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
+      with:
+        path: ${{ steps.key.outputs.path }}
+        key: ${{ steps.key.outputs.key }}

.github/actions/cache-esp-idf/action.yml

@@ -26,6 +26,9 @@ runs:
       # The native-IDF version is pinned in code, not in any file that feeds the
       # other cache keys, so resolve it explicitly. Keying on it means the cache
       # invalidates on a version bump (actions/cache never overwrites a key).
+      # Also key on the Python version: the cached IDF venv links to the
+      # runner's toolcache interpreter and is reinstalled every run after a
+      # runner image bump.
       id: version
       shell: bash
       run: |
@@ -36,19 +39,32 @@ runs:
           version=$(python -c 'from esphome.components.esp32 import ESP_IDF_FRAMEWORK_VERSION_LOOKUP as L; print(L["recommended"])')
         fi
         echo "version=$version" >> "$GITHUB_OUTPUT"
+        echo "python-version=$(python -c 'import platform; print(platform.python_version())')" >> "$GITHUB_OUTPUT"
     # Mirror the adjacent PlatformIO cache: only dev-branch runs write the
     # shared cache (so it lives in the default-branch scope readable by all
     # PRs), and PRs are restore-only -- they never push multi-GB artifacts into
-    # their own scope / the repo quota (e.g. on a version-bump PR).
+    # their own scope / the repo quota (e.g. on a version-bump PR). The
+    # ci-cache-write label lets a PR write into its own scope to test the hit path;
+    # that costs about 1GB of the repo cache quota per run, so remove it when done.
+    # -slim: bump when prune-esp-idf changes what it removes; a key is never overwritten.
     - name: Cache ESP-IDF install (write on dev)
-      if: github.ref == 'refs/heads/dev' && inputs.restore-only != 'true'
+      if: (github.ref == 'refs/heads/dev' || contains(github.event.pull_request.labels.*.name, 'ci-cache-write')) && inputs.restore-only != 'true'
       uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
       with:
         path: ~/.esphome-idf
-        key: ${{ runner.os }}-esphome-idf-${{ steps.version.outputs.version }}
+        key: ${{ runner.os }}-esphome-idf-${{ steps.version.outputs.version }}-py${{ steps.version.outputs.python-version }}-slim
     - name: Cache ESP-IDF install (restore-only off dev)
-      if: github.ref != 'refs/heads/dev' || inputs.restore-only == 'true'
+      if: github.ref != 'refs/heads/dev' && !contains(github.event.pull_request.labels.*.name, 'ci-cache-write') || inputs.restore-only == 'true'
       uses: actions/cache/restore@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
       with:
         path: ~/.esphome-idf
-        key: ${{ runner.os }}-esphome-idf-${{ steps.version.outputs.version }}
+        key: ${{ runner.os }}-esphome-idf-${{ steps.version.outputs.version }}-py${{ steps.version.outputs.python-version }}-slim
+    # Install explicitly so the prune below sees the toolchains on a cache miss
+    # too, instead of the install happening inside the first build step.
+    - name: Install ESP-IDF
+      shell: bash
+      run: |
+        . venv/bin/activate
+        python -c 'from esphome.espidf.framework import check_esp_idf_install; check_esp_idf_install("${{ steps.version.outputs.version }}")'
+    - name: Prune ESP-IDF install
+      uses: ./.github/actions/prune-esp-idf

.github/actions/prune-esp-idf/action.yml

@@ -0,0 +1,34 @@
+name: Prune ESP-IDF install
+description: >
+  Remove the picolibc sysroots (1.1GB of the 3.9GB install) from the native
+  ESP-IDF toolchains; IDF 5.x links newlib. Skipped when an IDF 6 install is
+  present, which links picolibc (see esp32/__init__.py).
+runs:
+  using: composite
+  steps:
+    - name: Prune picolibc
+      shell: bash
+      run: |
+        shopt -s nullglob
+        prefix="${ESPHOME_ESP_IDF_PREFIX:-$HOME/.esphome-idf}"
+        prefix="${prefix/#\~/$HOME}"
+        for fw in "$prefix"/frameworks/*/; do
+          case "$(basename "$fw")" in
+            [6-9].*) echo "IDF $(basename "$fw") installed, keeping picolibc"; exit 0 ;;
+          esac
+        done
+        n=0
+        for dir in "$prefix"/tools/*-esp-elf/*/*-esp-elf/picolibc; do
+          echo "Removing $dir ($(du -sh "$dir" | cut -f1))"
+          rm -rf "$dir"
+          n=$((n + 1))
+        done
+        # The marker rides along in the cache entry so a restored slim tree stays quiet.
+        if [ "$n" -gt 0 ]; then
+          touch "$prefix/.picolibc-pruned"
+        elif [ -d "$prefix/tools" ] && [ ! -f "$prefix/.picolibc-pruned" ]; then
+          echo "::warning::no picolibc sysroots matched under $prefix/tools"
+        fi
+        if [ -d "$prefix" ]; then
+          du -sh "$prefix"
+        fi

.github/workflows/ci.yml

@@ -355,6 +355,15 @@ jobs:
       fail-fast: false
       matrix:
         bucket: ${{ fromJson(needs.determine-jobs.outputs.integration-test-buckets) }}
+    env:
+      # What the cache steps persist; libdeps is excluded (keyed per xdist
+      # worker and env, it never crosses runs).
+      INTEGRATION_PIO_CACHE_PATH: |
+        ~/.esphome-integration-tests/platformio/platforms
+        ~/.esphome-integration-tests/platformio/packages
+        ~/.esphome-integration-tests/platformio/appstate.json
+        ~/.esphome-integration-tests/platformio/.cache
+        ~/.esphome-integration-tests/platformio/.esphome.pio.stamp.json
     steps:
       - name: Check out code from GitHub
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
@@ -373,6 +382,14 @@ jobs:
         uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
           python-version: "3.13"
+      - name: Restore integration PlatformIO cache
+        # Native platform + toolchain installed by shared_platformio_cache in
+        # tests/integration/conftest.py; a miss self-heals, so no restore-keys.
+        id: pio-cache
+        uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
+        with:
+          path: ${{ env.INTEGRATION_PIO_CACHE_PATH }}
+          key: integration-pio-v1-${{ runner.os }}-py${{ steps.python.outputs.python-version }}-${{ hashFiles('requirements.txt', 'tests/integration/fixtures/cache_init.yaml', 'esphome/components/host/__init__.py') }}
       - name: Restore Python virtual environment
         id: cache-venv
         uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
@@ -416,6 +433,13 @@ jobs:
         # esphome stores the PlatformIO ccache under the machine-global cache
         # dir (see _ccache_env() in esphome/platformio/toolchain.py).
         run: CCACHE_DIR="$HOME/.cache/esphome/platformio-ccache" ccache -s
+      - name: Save integration PlatformIO cache
+        # Bucket 0 only; the others would race the same immutable key.
+        if: success() && (github.ref == 'refs/heads/dev' || contains(github.event.pull_request.labels.*.name, 'ci-cache-write')) && strategy.job-index == 0 && steps.pio-cache.outputs.cache-hit != 'true'
+        uses: actions/cache/save@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
+        with:
+          path: ${{ env.INTEGRATION_PIO_CACHE_PATH }}
+          key: ${{ steps.pio-cache.outputs.cache-primary-key }}
 
   import-time:
     name: Check import esphome.__main__ time
@@ -649,6 +673,12 @@ jobs:
         with:
           framework: arduino
 
+      - name: Cache clang-tidy idedata
+        if: matrix.cache_idf
+        uses: ./.github/actions/cache-clang-tidy-idedata
+        with:
+          environment: esp32-arduino-tidy
+
       - name: Cache nRF Connect SDK install
         if: matrix.cache_sdk_nrf
         uses: ./.github/actions/cache-sdk-nrf
@@ -698,6 +728,10 @@ jobs:
           # Also cache libdeps, store them in a ~/.platformio subfolder
           PLATFORMIO_LIBDEPS_DIR: ~/.platformio/libdeps
 
+      - name: Prune ESP-IDF install before cache save
+        if: matrix.cache_idf && (github.ref == 'refs/heads/dev' || contains(github.event.pull_request.labels.*.name, 'ci-cache-write'))
+        uses: ./.github/actions/prune-esp-idf
+
       - name: Suggested changes
         run: script/ci-suggest-changes ${{ matrix.ignore_errors && '|| true' || '' }}
         # yamllint disable-line rule:line-length
@@ -730,6 +764,11 @@ jobs:
       - name: Cache ESP-IDF install
         uses: ./.github/actions/cache-esp-idf
 
+      - name: Cache clang-tidy idedata
+        uses: ./.github/actions/cache-clang-tidy-idedata
+        with:
+          environment: esp32-idf-tidy
+
       - name: Register problem matchers
         run: |
           echo "::add-matcher::.github/workflows/matchers/gcc.json"
@@ -764,6 +803,10 @@ jobs:
           # Also cache libdeps, store them in a ~/.platformio subfolder
           PLATFORMIO_LIBDEPS_DIR: ~/.platformio/libdeps
 
+      - name: Prune ESP-IDF install before cache save
+        if: (github.ref == 'refs/heads/dev' || contains(github.event.pull_request.labels.*.name, 'ci-cache-write'))
+        uses: ./.github/actions/prune-esp-idf
+
       - name: Suggested changes
         run: script/ci-suggest-changes
         if: always()
@@ -809,6 +852,11 @@ jobs:
       - name: Cache ESP-IDF install
         uses: ./.github/actions/cache-esp-idf
 
+      - name: Cache clang-tidy idedata
+        uses: ./.github/actions/cache-clang-tidy-idedata
+        with:
+          environment: esp32-idf-tidy
+
       - name: Register problem matchers
         run: |
           echo "::add-matcher::.github/workflows/matchers/gcc.json"
@@ -843,6 +891,10 @@ jobs:
           # Also cache libdeps, store them in a ~/.platformio subfolder
           PLATFORMIO_LIBDEPS_DIR: ~/.platformio/libdeps
 
+      - name: Prune ESP-IDF install before cache save
+        if: (github.ref == 'refs/heads/dev' || contains(github.event.pull_request.labels.*.name, 'ci-cache-write'))
+        uses: ./.github/actions/prune-esp-idf
+
       - name: Suggested changes
         run: script/ci-suggest-changes
         if: always()
@@ -866,16 +918,19 @@ jobs:
             name: Run script/clang-tidy for ESP32 S3
             # yamllint disable-line rule:line-length
             options: --environment esp32s3-idf-tidy --grep SOC_TEMP_SENSOR_SUPPORTED --grep USE_ESP32_VARIANT_ESP32S3 --grep USE_LOGGER_USB_CDC
+            tidy_environment: esp32s3-idf-tidy
           - id: clang-tidy
             name: Run script/clang-tidy for ESP32 P4
             # P4 has no native Wi-Fi/BLE; those run over the hosted co-processor,
             # so their code paths differ -- lint them under the P4 build too.
             # yamllint disable-line rule:line-length
             options: --environment esp32p4-idf-tidy --grep USE_ESP32_VARIANT_ESP32P4 --grep USE_ESP32_HOSTED --grep USE_WIFI --grep USE_BLE
+            tidy_environment: esp32p4-idf-tidy
           - id: clang-tidy
             name: Run script/clang-tidy for ESP32 C6
             # yamllint disable-line rule:line-length
             options: --environment esp32c6-idf-tidy --grep SOC_LP_I2C_SUPPORTED --grep USE_ESP32_VARIANT_ESP32C6 --grep USE_OPENTHREAD --grep USE_ZIGBEE
+            tidy_environment: esp32c6-idf-tidy
 
     steps:
       - name: Check out code from GitHub
@@ -893,6 +948,11 @@ jobs:
       - name: Cache ESP-IDF install
         uses: ./.github/actions/cache-esp-idf
 
+      - name: Cache clang-tidy idedata
+        uses: ./.github/actions/cache-clang-tidy-idedata
+        with:
+          environment: ${{ matrix.tidy_environment }}
+
       - name: Register problem matchers
         run: |
           echo "::add-matcher::.github/workflows/matchers/gcc.json"
@@ -926,6 +986,10 @@ jobs:
             script/clang-tidy --fix --changed ${{ matrix.options }}
           fi
 
+      - name: Prune ESP-IDF install before cache save
+        if: (github.ref == 'refs/heads/dev' || contains(github.event.pull_request.labels.*.name, 'ci-cache-write'))
+        uses: ./.github/actions/prune-esp-idf
+
       - name: Suggested changes
         run: script/ci-suggest-changes
         if: always()

CODEOWNERS

@@ -350,6 +350,7 @@ esphome/components/mipi_spi/* @clydebarrow
 esphome/components/mitsubishi/* @RubyBailey
 esphome/components/mitsubishi_cn105/* @crnjan
 esphome/components/mixer/speaker/* @kahrendt
+esphome/components/mk2pvrouter/* @FredM67
 esphome/components/mlx90393/* @functionpointer
 esphome/components/mlx90614/* @jesserockz
 esphome/components/mmc5603/* @benhoff

esphome/__main__.py

@@ -1670,20 +1670,26 @@ def command_compile(args: ArgsProtocol, config: ConfigType) -> int | None:
     if exit_code != 0:
         return exit_code
     if CORE.is_host:
-        if CORE.using_toolchain_esp_idf:
-            from esphome.espidf import toolchain
-
-            program_path = str(toolchain.get_elf_path())
-        else:
-            from esphome.platformio.toolchain import get_idedata
-
-            program_path = str(get_idedata(config).firmware_elf_path)
-        _LOGGER.info("Successfully compiled program to path '%s'", program_path)
+        _LOGGER.info(
+            "Successfully compiled program to path '%s'", _host_program_path(config)
+        )
     else:
         _LOGGER.info("Successfully compiled program.")
     return 0
 
 
+def _host_program_path(config: ConfigType) -> str:
+    """Return the compiled host ELF path."""
+    if CORE.using_toolchain_esp_idf:
+        from esphome.espidf import toolchain
+
+        return str(toolchain.get_elf_path())
+    from esphome.platformio.toolchain import get_idedata
+
+    # Memoized by compile_program's own call; this is a dict lookup
+    return str(get_idedata(config).firmware_elf_path)
+
+
 def command_upload(args: ArgsProtocol, config: ConfigType) -> int | None:
     # Get devices, resolving special identifiers like OTA
     devices = choose_upload_log_host(
@@ -1728,14 +1734,7 @@ def command_run(args: ArgsProtocol, config: ConfigType) -> int | None:
         return exit_code
     _LOGGER.info("Successfully compiled program.")
     if CORE.is_host:
-        if CORE.using_toolchain_esp_idf:
-            from esphome.espidf import toolchain
-
-            program_path = str(toolchain.get_elf_path())
-        else:
-            from esphome.platformio.toolchain import get_idedata
-
-            program_path = str(get_idedata(config).firmware_elf_path)
+        program_path = _host_program_path(config)
         _LOGGER.info("Running program from path '%s'", program_path)
         return run_external_process(program_path)
 

esphome/arduino/library.py

@@ -0,0 +1,531 @@
+"""Arduino-core backend for the shared PlatformIO library converter.
+
+Bundled names build straight from the framework tree; everything else goes
+through ``esphome.platformio.library``. Mirrors ``lib_ldf_mode=off``: each
+library builds its own archive; all include dirs join one global path.
+
+Deviations from PlatformIO: flat-layout libraries get the recursive default
+source filter; ``dot_a_linkage`` is honored; bundled libraries never run a
+manifest ``extraScript``; manifest ``-I`` flags join the global include path;
+``precompiled``/``ldflags`` properties are refused by name.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+import logging
+from pathlib import Path
+import re
+
+from esphome.core import CORE, EsphomeError, Library
+from esphome.helpers import walk_files
+from esphome.platformio.extra_script import apply_extra_script
+from esphome.platformio.library import (
+    DEFAULT_BUILD_INCLUDE_DIR,
+    DEFAULT_BUILD_SRC_FILTER,
+    ESPHOME_DATA_KEY,
+    ESPHOME_DATA_LINK_FLAGS_KEY,
+    LIBRARY_HEADER_SUFFIXES,
+    SRC_FILE_EXTENSIONS,
+    ConvertedLibrary,
+    IncompatiblePlatform,
+    InvalidLibrary,
+    LibraryBackend,
+    _url_or_none,
+    check_library_data,
+    collect_filtered_files,
+    convert_libraries,
+    ensure_list,
+    is_lib_ignored,
+    lex_build_flags,
+    lib_ignore_set,
+    normalize_dependencies,
+    parse_library_json,
+    parse_library_properties,
+    warn_properties_depends,
+)
+
+_LOGGER = logging.getLogger(__name__)
+
+
+@dataclass
+class ArduinoLibrary:
+    """One resolved library, ready for the ninja generator."""
+
+    name: str
+    sources: list[Path] = field(default_factory=list)
+    include_dirs: list[Path] = field(default_factory=list)
+    # Extra compile flags private to this library's own sources
+    flags: list[str] = field(default_factory=list)
+    # PlatformIO's build.libArchive / Arduino's dot_a_linkage: when False the
+    # objects go to the linker directly (symbols nothing references survive)
+    lib_archive: bool = True
+    # Link inputs the library contributes (-L dirs / -l libs, e.g. from
+    # precompiled vendor blobs) and -Wl, options for the firmware link
+    link_dirs: list[Path] = field(default_factory=list)
+    link_libs: list[str] = field(default_factory=list)
+    link_flags: list[str] = field(default_factory=list)
+
+
+# Source-like suffixes the case-sensitive suffix map rejects
+_UNMAPPED_SOURCE_SUFFIXES = frozenset(
+    {s.lower() for s in SRC_FILE_EXTENSIONS} | {".ino"}
+)
+
+# Filename-plain names: an allowlist excludes separators, drive colons,
+# and dot-only names by shape
+_SAFE_LIBRARY_NAME_RE = re.compile(r"[A-Za-z0-9_][A-Za-z0-9_. +-]*\Z")
+
+
+def _is_safe_library_name(name: object) -> bool:
+    """Whether a name may be joined under the framework's libraries dir."""
+    return isinstance(name, str) and _SAFE_LIBRARY_NAME_RE.fullmatch(name) is not None
+
+
+def _manifest_build(name: str, data: object) -> dict:
+    """The manifest's ``build`` section; malformed manifests fail by name."""
+    build = data.get("build", {}) if isinstance(data, dict) else None
+    if not isinstance(build, dict):
+        raise EsphomeError(f"Library {name} has a malformed manifest")
+    return build
+
+
+def _resolve_src_dir(name: str, read_path: Path, build: dict) -> str:
+    """Resolve PIO's source dir: manifest srcDir, else src/Src, else the root."""
+    if "srcDir" not in build:
+        return next((d for d in ("src", "Src") if (read_path / d).is_dir()), ".")
+    # A declared srcDir (falsy included) that does not resolve is a manifest error
+    src_dir = build["srcDir"]
+    if not (isinstance(src_dir, str) and src_dir and (read_path / src_dir).is_dir()):
+        raise EsphomeError(
+            f"Library {name} declares srcDir {src_dir!r} which does not exist"
+        )
+    return src_dir
+
+
+def _reject_unsupported_link_fields(name: str, data: dict) -> None:
+    # PIO honors these; ignoring them would fail at link with no stated
+    # cause. Property values are strings, so "false" is not a declaration.
+    precompiled = data.get("precompiled")
+    if precompiled and str(precompiled).strip().lower() != "false":
+        raise EsphomeError(
+            f"Library {name} declares precompiled, which this backend does not support"
+        )
+    if data.get("ldflags"):
+        raise EsphomeError(
+            f"Library {name} declares ldflags, which this backend does not support"
+        )
+
+
+def _resolve_lib_archive(name: str, data: dict, build: dict) -> bool:
+    """build.libArchive, else dot_a_linkage (an Arduino IDE property PIO
+    ignores; a deliberate extra), else archive."""
+
+    # Strict parse: bool("false") is True
+    def _parse(key: str, raw: object) -> bool:
+        if isinstance(raw, bool):
+            return raw
+        value = str(raw).strip().lower()
+        if value in ("true", "false"):
+            return value == "true"
+        raise EsphomeError(f"Library {name} has a malformed {key} value {raw!r}")
+
+    if "libArchive" in build:
+        return _parse("libArchive", build["libArchive"])
+    if "dot_a_linkage" in data:
+        return _parse("dot_a_linkage", data["dot_a_linkage"])
+    return True
+
+
+def _classify_build_flags(
+    name: str, read_path: Path, lib: ArduinoLibrary, flag_tokens: list[str]
+) -> list[str]:
+    """Route the lexed build.flags into the library's flag lists.
+
+    Returns the ``-I`` arguments for the include-dir resolution.
+    """
+    include_flags: list[str] = []
+    for tok in flag_tokens:
+        if tok.startswith("-I"):
+            include_flags.append(tok[2:])
+        elif tok.startswith("-L"):
+            link_dir = (read_path / tok[2:]).resolve()
+            if not link_dir.is_dir():
+                # Kept (the linker ignores missing -L dirs); the warning
+                # names the culprit before a bare "cannot find -lfoo"
+                _LOGGER.warning(
+                    "Library %s declares library dir %s which does not exist",
+                    name,
+                    tok[2:],
+                )
+            lib.link_dirs.append(link_dir)
+        elif tok.startswith("-l"):
+            lib.link_libs.append(tok[2:])
+        elif tok.startswith("-Wl,"):
+            lib.link_flags.append(tok)
+        else:
+            lib.flags.append(tok)
+    return include_flags
+
+
+def _resolve_include_dirs(
+    name: str,
+    read_path: Path,
+    lib: ArduinoLibrary,
+    build: dict,
+    src_dir: str,
+    include_flags: list[str],
+) -> None:
+    include_dir = build.get("includeDir", DEFAULT_BUILD_INCLUDE_DIR)
+    if not isinstance(include_dir, str):
+        raise EsphomeError(f"Library {name} has a malformed includeDir")
+    for d, explicit in [
+        (include_dir, "includeDir" in build),
+        (src_dir, False),  # _resolve_src_dir already validated it
+        *((flag, True) for flag in include_flags),
+    ]:
+        if (path := (read_path / d)).is_dir():
+            lib.include_dirs.append(path.resolve())
+        elif explicit:
+            # Warn-and-drop (unlike srcDir): a missing include dir is
+            # harmless until a header is needed, and the compile names it
+            _LOGGER.warning(
+                "Library %s declares include dir %s which does not exist", name, d
+            )
+
+
+def _collect_lib_sources(
+    name: str,
+    read_path: Path,
+    lib: ArduinoLibrary,
+    src_dir: str,
+    src_filter: list[str],
+) -> None:
+    sources: list[Path] = []
+    dropped: list[str] = []
+    saw_header = False
+    for f in collect_filtered_files(read_path / src_dir, src_filter):
+        path = Path(f)
+        suffix = path.suffix
+        if suffix in SRC_FILE_EXTENSIONS:
+            # resolve() per file: srcFilter patterns may escape src_dir
+            sources.append(path.resolve())
+        elif suffix.lower() in _UNMAPPED_SOURCE_SUFFIXES:
+            # A source-like suffix the case-sensitive map rejects (.CPP,
+            # .ino) is a dropped compilation unit; headers fall through
+            dropped.append(path.name)
+        elif suffix.lower() in LIBRARY_HEADER_SUFFIXES:
+            saw_header = True
+    lib.sources = sorted(sources)
+    if dropped:
+        _LOGGER.warning(
+            "Library %s: %d file(s) with unmapped source suffixes are not compiled: %s",
+            name,
+            len(dropped),
+            ", ".join(sorted(dropped)),
+        )
+    if not lib.sources and not saw_header:
+        # Matched headers mean header-only; a filter matching nothing is
+        # a manifest/tree problem (a truly empty tree raises elsewhere)
+        _LOGGER.warning("Library %s: no source files matched", name)
+
+
+def _library_info(name: str, read_path: Path, data: dict) -> ArduinoLibrary:
+    """Resolve one library's sources, include dirs, and flags (PIO semantics)."""
+    build = _manifest_build(name, data)
+    _reject_unsupported_link_fields(name, data)
+    src_dir = _resolve_src_dir(name, read_path, build)
+    src_filter = ensure_list(build.get("srcFilter", DEFAULT_BUILD_SRC_FILTER))
+    if not all(isinstance(entry, str) for entry in src_filter):
+        raise EsphomeError(f"Library {name} has a malformed srcFilter")
+    lib = ArduinoLibrary(name=name, lib_archive=_resolve_lib_archive(name, data, build))
+    # PlatformIO shell-lexes each build.flags entry
+    include_flags = _classify_build_flags(
+        name, read_path, lib, lex_build_flags(build.get("flags", []), f"library {name}")
+    )
+    _resolve_include_dirs(name, read_path, lib, build, src_dir, include_flags)
+    _collect_lib_sources(name, read_path, lib, src_dir, src_filter)
+    return lib
+
+
+def _bundled_library(framework_path: Path, name: str) -> ArduinoLibrary:
+    """A library bundled with the Arduino core, read from the framework tree.
+
+    ``library.json`` wins over ``library.properties`` when both exist, as in
+    PlatformIO's LibBuilderFactory; only the JSON manifest can carry a
+    ``build`` section (srcDir, srcFilter, flags).
+    """
+    lib_dir = framework_path / "libraries" / name
+    manifest_json = lib_dir / "library.json"
+    if manifest_json.is_file():
+        try:
+            data = parse_library_json(manifest_json)
+        except ValueError as err:  # JSONDecodeError
+            raise EsphomeError(
+                f"Bundled library {name} has a corrupt library.json ({err}); "
+                "the framework install may be incomplete (run 'esphome clean-all')"
+            ) from err
+    elif (manifest := lib_dir / "library.properties").is_file():
+        data = parse_library_properties(manifest)
+    else:
+        # Debug, not warning: the legacy manifest-less layout is legal and
+        # the 3.1.2 core ships one such library (FSTools), so a warning
+        # would be unactionable noise on every build using it
+        _LOGGER.debug("Bundled library %s has no manifest; using defaults", name)
+        data = {}
+    if isinstance(data, dict):
+        # Bundled manifest deps are never walked; make the skip visible
+        if data.get("dependencies"):
+            _LOGGER.warning(
+                "Bundled library %s declares dependencies, which are not "
+                "resolved automatically; add them with add_library() if needed",
+                name,
+            )
+        warn_properties_depends(name, data)
+        build = data.get("build")
+        if isinstance(build, dict) and build.get("extraScript"):
+            # Scripts only run on the converted path; building without
+            # the script's flags would miscompile
+            raise EsphomeError(
+                f"Bundled library {name} declares an extraScript, which is "
+                "not run for bundled libraries"
+            )
+    lib = _library_info(name, lib_dir, data)
+    _assert_tree_has_code(
+        name,
+        lib_dir,
+        "the framework install may be incomplete (run 'esphome clean-all')",
+    )
+    return lib
+
+
+def _assert_tree_has_code(name: str, root: Path, hint: str) -> None:
+    """An empty or half-extracted tree can never link; fail by name (a
+    warning would scroll away and resurface as undefined symbols)."""
+    if not any(
+        Path(p).suffix in SRC_FILE_EXTENSIONS
+        or Path(p).suffix.lower() in LIBRARY_HEADER_SUFFIXES
+        for p in walk_files(root)
+    ):
+        raise EsphomeError(f"Library {name} has no sources or headers; {hint}")
+
+
+def _external_short_name(name: str) -> str:
+    """The short library name of a requested spec.
+
+    "owner/Name" and plain names take the last path segment; "Name=<url>"
+    takes the declared name. Git tails (".git", "#ref") are stripped like
+    the walk's URL normalization; the comparand is a manifest dependency
+    name, never a spec.
+    """
+    head, sep, tail = name.partition("=")
+    if sep and "://" in tail:
+        return head
+    short = name.rsplit("/", maxsplit=1)[-1]
+    return short.partition("#")[0].removesuffix(".git")
+
+
+def _check_unfulfilled_provides(
+    provided_requests: set[str], satisfied: set[str], still_requested: set[str]
+) -> None:
+    """Fail by name when a walk-skipped dependency was never added.
+
+    An unfulfilled provides() promise only surfaces as undefined symbols
+    at link. The walk records across re-resolutions, so a name no final
+    manifest still requests is stale state, never a failure.
+    """
+    if missing := sorted((provided_requests & still_requested) - satisfied):
+        raise EsphomeError(
+            "provides() skipped these dependencies but nothing added them: "
+            f"{', '.join(missing)}; the build is missing libraries"
+        )
+
+
+def resolve_libraries(
+    framework_path: Path, *, pio_platform: str, board_mcu: str, cache_key: str
+) -> list[ArduinoLibrary]:
+    """Resolve every ``cg.add_library()`` entry into an :class:`ArduinoLibrary`.
+
+    ``pio_platform``/``board_mcu`` filter manifests the way PlatformIO would
+    for that core (e.g. ``espressif8266``/``esp8266``); ``cache_key`` keys the
+    shared converter's download cache.
+
+    The returned list is not topologically sorted, so the caller must link
+    the archives inside one ``--start-group``/``--end-group`` pair (the
+    bundled-first grouping is incidental).
+    """
+    bundled: list[ArduinoLibrary] = []
+    external: list[Library] = []
+    # PlatformIO's lib_ignore covers framework-bundled libraries too; the
+    # shared converter only filters the registry/git ones.
+    lib_ignore = lib_ignore_set()
+    # Exact directory names keep membership case-sensitive everywhere
+    # (an is_dir() probe would match "wire" on macOS/Windows and build
+    # the bundled Wire twice)
+    libraries_dir = framework_path / "libraries"
+    if not libraries_dir.is_dir():
+        # A registry fallback would fail later with a misleading
+        # package-not-found error per bundled name
+        raise EsphomeError(
+            f"{libraries_dir} is missing; the framework install may be "
+            "incomplete (run 'esphome clean-all')"
+        )
+    bundled_dir_names = frozenset(p.name for p in libraries_dir.iterdir() if p.is_dir())
+
+    def _provided(name: object) -> bool:
+        return _is_safe_library_name(name) and name in bundled_dir_names
+
+    for library in CORE.platformio_libraries.values():
+        if is_lib_ignored(library.name, lib_ignore):
+            continue
+        # Bundled only for a bare name with a matching framework dir; pinned
+        # or unmatched names resolve from the registry, as under PlatformIO.
+        if not library.repository and not library.version and _provided(library.name):
+            # Bundled manifest deps are not walked; _bundled_library warns
+            bundled.append(_bundled_library(framework_path, library.name))
+        else:
+            external.append(library)
+
+    converted: list[ArduinoLibrary] = []
+    bundled_names = {lib.name for lib in bundled}
+    converted_manifest_names: set[str] = set()
+    # Bundled candidates skipped on purpose (platform filter); the
+    # provides() reconciliation must count them as satisfied
+    knowingly_skipped: set[str] = set()
+    # Dependency names of the manifests actually emitted; a walk recording
+    # for a since-re-resolved manifest must not fail the reconciliation
+    final_dep_names: set[str] = set()
+    # Ordered set of bundled dependency names to add once conversion is done
+    pending_bundled: dict[str, None] = {}
+    # Deps matching a separately-requested external are already in the build
+    # (a duplicate archive means duplicate-symbol link errors)
+    external_short_names = {
+        _external_short_name(lib.name) for lib in external if lib.name
+    }
+
+    def _add_bundled_dependencies(component: ConvertedLibrary) -> None:
+        # A version-less bare name ("Hash") is a core-bundled library the
+        # shared converter cannot resolve from the registry
+        for dep in normalize_dependencies(
+            component.data.get("dependencies"), component.name
+        ):
+            # normalize_dependencies guarantees a non-empty str name
+            name = dep["name"]
+            final_dep_names.add(name)
+            if "/" in name:
+                owner, _, pkg = name.partition("/")
+                if _is_safe_library_name(owner) and _is_safe_library_name(pkg):
+                    # Owner-qualified; the converter resolves it from the registry
+                    continue
+            if not _is_safe_library_name(name):
+                # The name becomes a path component; never join a traversal
+                _LOGGER.warning(
+                    "Ignoring malformed dependency entry %r of library %s",
+                    dep,
+                    component.name,
+                )
+                continue
+            if name in external_short_names:
+                if _provided(name):
+                    # A bundled copy is suppressed; a coincidental name
+                    # collision would surface as link errors
+                    _LOGGER.warning(
+                        "Dependency %s of %s is assumed satisfied by a "
+                        "requested external library; the bundled copy is "
+                        "not added",
+                        name,
+                        component.name,
+                    )
+                else:
+                    _LOGGER.debug(
+                        "Dependency %s of %s assumed satisfied by a requested "
+                        "external library",
+                        name,
+                        component.name,
+                    )
+                continue
+            if name in bundled_names or is_lib_ignored(name, lib_ignore):
+                continue
+            if _url_or_none(dep.get("version")) is not None:
+                # A URL names one specific source; never add the bundled copy
+                continue
+            if dep.get("owner") or not _provided(name):
+                # Only owner-less framework-tree names take the bundled
+                # copy (PIO's process_dependencies); the walk reports drops
+                continue
+            try:
+                # framework=None: the walk already warned for non-platform
+                # causes; debug keeps one fault from warning twice (pinned
+                # by test_nonplatform_rejection_warns_once_through_real_converter)
+                check_library_data(dep, pio_platform, None)
+            except IncompatiblePlatform as err:
+                # A knowing skip (platform filter), not a broken promise
+                knowingly_skipped.add(name)
+                _LOGGER.debug("Skip bundled candidate %s: %s", name, err)
+                continue
+            except InvalidLibrary as err:
+                # Malformed manifest data never counts as satisfied; the
+                # walk owns the warning (see the warns-once test above)
+                _LOGGER.debug("Skip malformed bundled candidate %s: %s", name, err)
+                continue
+            # Deferred: a later manifest name may satisfy this
+            pending_bundled.setdefault(name)
+
+    def _emit(component: ConvertedLibrary) -> None:
+        apply_extra_script(
+            component, board_mcu=lambda: board_mcu, pio_platform=pio_platform
+        )
+        _assert_tree_has_code(
+            component.get_require_name(),
+            component.source_dir,
+            "the download may be incomplete (run 'esphome clean-all')",
+        )
+        if isinstance(manifest_name := component.data.get("name"), str):
+            converted_manifest_names.add(manifest_name)
+        lib = _library_info(
+            component.get_require_name(), component.source_dir, component.data
+        )
+        # Extra-script LINKFLAGS travel outside build.flags; dropping
+        # them would link wrong with no stated cause
+        lib.link_flags.extend(
+            component.data.get(ESPHOME_DATA_KEY, {}).get(
+                ESPHOME_DATA_LINK_FLAGS_KEY, []
+            )
+        )
+        converted.append(lib)
+        _add_bundled_dependencies(component)
+
+    backend = LibraryBackend(
+        platform=pio_platform,
+        framework="arduino",
+        emit=_emit,
+        cache_key=cache_key,
+        # The walk must not resolve bundled names from the registry;
+        # _add_bundled_dependencies adds them after emit
+        provides=_provided,
+    )
+    if external:
+        convert_libraries(external, backend)
+    for name in pending_bundled:
+        if name in converted_manifest_names:
+            # The converted library is this one; the bundled copy would
+            # double the archive. Warn like the external_short_names twin.
+            _LOGGER.warning(
+                "Dependency %s is assumed satisfied by a converted library's "
+                "manifest name; the bundled copy is not added",
+                name,
+            )
+            continue
+        bundled_names.add(name)
+        bundled.append(_bundled_library(framework_path, name))
+
+    _check_unfulfilled_provides(
+        backend.provided_requests,
+        bundled_names
+        | converted_manifest_names
+        | external_short_names
+        | knowingly_skipped,
+        final_dep_names,
+    )
+
+    return bundled + converted

esphome/build_gen/build_tool.py

@@ -0,0 +1,108 @@
+"""Tiny cross-platform build steps invoked from the generated ninja file.
+
+Plain script (not ``python -m``): it runs from ninja with whatever Python
+started esphome and must not depend on the package being importable.
+
+Subcommands:
+    ar <ar-binary> <archive> <rspfile>   remove stale archive, then ``ar rcs``
+    copy <src> <dst>                     copy a file
+
+The ar rspfile carries one object path per line (the generating rule must
+use ``$in_newline``, never ``$in``).
+"""
+
+from pathlib import Path
+import shutil
+import subprocess
+import sys
+
+
+def _read_rspfile(rspfile: str) -> list[str]:
+    r"""The object paths listed in ``rspfile``, unquoted.
+
+    GNU ar treats backslashes in response files as escapes (corrupts
+    Windows paths), so the caller expands the list into argv; strip the
+    simple surrounding quote ninja adds to special paths, then undo
+    ninja's POSIX escape for an embedded quote ('a'\\''b.o' -> a'b.o).
+    """
+    return [
+        line[1:-1].replace("'\\''", "'")
+        if len(line) >= 2 and line[0] == line[-1] and line[0] in "'\""
+        else line
+        for line in Path(rspfile).read_text(encoding="utf-8").splitlines()
+        if line
+    ]
+
+
+def _run_ar(ar: str, archive: str, rspfile: str) -> int:
+    # Remove first: ``ar rcs`` replaces members but never drops ones whose
+    # source was removed from the build, which would leak stale objects.
+    Path(archive).unlink(missing_ok=True)
+    objects = _read_rspfile(rspfile)
+    if not objects:
+        # An empty archive would "succeed" here and fail far away at link
+        print(f"ar: no objects listed in {rspfile} for {archive}", file=sys.stderr)
+        return 1
+    # Batch by argv length: expanding the rspfile gives back the Windows
+    # 32767-char command-line limit it existed to avoid. "rcs" creates,
+    # "qs" appends; the s keeps the symbol index explicit on every ar.
+    op = "rcs"
+    ok = False
+    try:
+        while objects:
+            batch = [objects.pop(0)]
+            batch_len = len(batch[0])
+            while objects and batch_len + len(objects[0]) < 25000:
+                batch_len += len(objects[0]) + 1
+                batch.append(objects.pop(0))
+            rc = subprocess.run(
+                [ar, op, archive, *batch], check=False, close_fds=False
+            ).returncode
+            if rc != 0:
+                return rc
+            op = "qs"
+        ok = True
+        return 0
+    finally:
+        if not ok:
+            # Any failure (bad exit, missing ar binary, interrupt) must not
+            # leave a truncated archive behind
+            Path(archive).unlink(missing_ok=True)
+
+
+def _run_copy(src: str, dst: str) -> int:
+    try:
+        shutil.copyfile(src, dst)
+    except OSError as err:
+        # Never leave a partially written output (e.g. a firmware image);
+        # SameFileError means dst IS src, where unlinking destroys the input
+        if not isinstance(err, shutil.SameFileError):
+            Path(dst).unlink(missing_ok=True)
+        print(f"copy: {src} -> {dst} failed: {err}", file=sys.stderr)
+        return 1
+    return 0
+
+
+# mode -> (handler, expected operand count); surplus argv means a
+# mis-specified ninja rule and must error, not silently drop operands
+_MODES = {"ar": (_run_ar, 3), "copy": (_run_copy, 2)}
+
+
+def main() -> int:
+    mode = sys.argv[1] if len(sys.argv) > 1 else ""
+    if entry := _MODES.get(mode):
+        handler, argc = entry
+        args = sys.argv[2:]
+        if len(args) != argc:
+            print(
+                f"build_tool {mode}: expected {argc} arguments, got {len(args)}",
+                file=sys.stderr,
+            )
+            return 1
+        return handler(*args)
+    print(f"unknown build_tool mode: {mode}", file=sys.stderr)
+    return 1
+
+
+if __name__ == "__main__":  # pragma: no cover
+    sys.exit(main())

esphome/codegen.py

@@ -78,6 +78,7 @@ from esphome.cpp_types import (  # noqa: F401
     StringRef,
     arduino_json_ns,
     bool_,
+    char,
     const_char_ptr,
     double,
     esphome_ns,

esphome/components/api/__init__.py

@@ -5,6 +5,7 @@ from typing import Any
 from esphome import automation
 from esphome.automation import Condition
 import esphome.codegen as cg
+from esphome.components.const import CONF_DESCRIPTION
 from esphome.components.logger import request_log_listener
 
 # ENCRYPTION_SCHEMA and validate_encryption_key are re-exported for external
@@ -41,10 +42,12 @@ from esphome.const import (
     CONF_TAG,
     CONF_THEN,
     CONF_TRIGGER_ID,
+    CONF_TYPE,
     CONF_VARIABLES,
 )
 from esphome.core import CORE, ID, CoroPriority, EsphomeError, coroutine_with_priority
 from esphome.cpp_generator import MockObj, TemplateArgsType
+from esphome.helpers import fnv1_hash
 from esphome.types import ConfigFragmentType, ConfigType
 
 # Compat alias: downstream consumers (e.g. device-builder) referenced the
@@ -125,6 +128,7 @@ SERVICE_ARG_FALLBACK_TYPES: dict[str, MockObj] = {
 }
 CONF_BATCH_DELAY = "batch_delay"
 CONF_CUSTOM_SERVICES = "custom_services"
+CONF_EXAMPLE = "example"
 CONF_HOMEASSISTANT_SERVICES = "homeassistant_services"
 CONF_HOMEASSISTANT_STATES = "homeassistant_states"
 CONF_LISTEN_BACKLOG = "listen_backlog"
@@ -228,14 +232,30 @@ def _validate_supports_response(value: Any) -> str:
     return cv.enum(SUPPORTS_RESPONSE_OPTIONS, lower=True)(value)
 
 
+# ESP8266 copies every string of an action into a stack buffer sized by codegen; keep it small
+ESP8266_ACTION_STRINGS_MAX_TOTAL = 384
+
+VARIABLE_SCHEMA = cv.Schema(
+    {
+        cv.Required(CONF_TYPE): cv.one_of(*SERVICE_ARG_NATIVE_TYPES, lower=True),
+        cv.Optional(CONF_DESCRIPTION): cv.string_strict,
+        cv.Optional(CONF_EXAMPLE): cv.string_strict,
+    }
+)
+
+# Accepts the plain `name: type` shorthand or the full mapping form
+validate_variable = cv.maybe_simple_value(VARIABLE_SCHEMA, key=CONF_TYPE)
+
+
 ACTIONS_SCHEMA = automation.validate_automation(
     {
         cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(UserServiceTrigger),
         cv.Exclusive(CONF_SERVICE, group_of_exclusion=CONF_ACTION): cv.valid_name,
         cv.Exclusive(CONF_ACTION, group_of_exclusion=CONF_ACTION): cv.valid_name,
+        cv.Optional(CONF_DESCRIPTION): cv.string_strict,
         cv.Optional(CONF_VARIABLES, default={}): cv.Schema(
             {
-                cv.validate_id_name: cv.one_of(*SERVICE_ARG_NATIVE_TYPES, lower=True),
+                cv.validate_id_name: validate_variable,
             }
         ),
         # No default - auto-detected by _auto_detect_supports_response
@@ -352,6 +372,85 @@ CONFIG_SCHEMA = cv.All(
 )
 
 
+def _has_action_metadata(actions: list[ConfigType]) -> bool:
+    # Empty strings count as unset, matching _action_strings
+    return any(
+        conf.get(CONF_DESCRIPTION)
+        or any(
+            var_.get(CONF_DESCRIPTION) or var_.get(CONF_EXAMPLE)
+            for var_ in conf[CONF_VARIABLES].values()
+        )
+        for conf in actions
+    )
+
+
+def _action_strings(conf: ConfigType, has_metadata: bool) -> list[str | None]:
+    """Strings of one action in the table order UserServiceStatic (user_services.h) expects."""
+    # An empty description or example is treated as unset
+    strings: list[str | None] = [conf[CONF_ACTION]]
+    if has_metadata:
+        strings.append(conf.get(CONF_DESCRIPTION) or None)
+    for name, var_ in conf[CONF_VARIABLES].items():
+        strings.append(name)
+        if has_metadata:
+            strings += [
+                var_.get(CONF_DESCRIPTION) or None,
+                var_.get(CONF_EXAMPLE) or None,
+            ]
+    return strings
+
+
+def _action_strings_size(strings: list[str | None]) -> int:
+    """Bytes needed to copy every string out of flash, each with its terminator."""
+    return sum(
+        len(string.encode("utf-8")) + 1 for string in strings if string is not None
+    )
+
+
+def _validate_esp8266_action_strings(config: ConfigType) -> ConfigType:
+    if not CORE.is_esp8266:
+        return config
+    actions = config.get(CONF_ACTIONS, [])
+    has_metadata = _has_action_metadata(actions)
+    for conf in actions:
+        size = _action_strings_size(_action_strings(conf, has_metadata))
+        if size > ESP8266_ACTION_STRINGS_MAX_TOTAL:
+            raise cv.Invalid(
+                f"Action '{conf[CONF_ACTION]}' has {size} bytes of name, variable name, "
+                f"description and example text; ESP8266 allows at most "
+                f"{ESP8266_ACTION_STRINGS_MAX_TOTAL} bytes per action"
+            )
+    return config
+
+
+FINAL_VALIDATE_SCHEMA = _validate_esp8266_action_strings
+
+
+def _add_action_strings(
+    index: int, strings: list[str | None], interned: dict[str, MockObj]
+) -> MockObj:
+    """Emit the PROGMEM string table for one action.
+
+    Each string is its own PROGMEM array because on ESP8266 .rodata is RAM, and identical
+    strings are shared between actions through `interned`.
+    """
+    entries: list[MockObj] = []
+    for string in strings:
+        if string is None:
+            entries.append(cg.nullptr)
+            continue
+        if (var := interned.get(string)) is None:
+            var = interned[string] = cg.progmem_array(
+                ID(f"api_action_str{len(interned)}", is_declaration=True, type=cg.char),
+                string,
+            )
+        entries.append(var)
+    return cg.progmem_array(
+        ID(f"api_action{index}_strings", is_declaration=True, type=cg.const_char_ptr),
+        entries,
+    )
+
+
 @coroutine_with_priority(CoroPriority.WEB)
 async def to_code(config: ConfigType) -> None:
     var = cg.new_Pvariable(config[CONF_ID])
@@ -371,8 +470,10 @@ async def to_code(config: ConfigType) -> None:
     cg.add_define("MAX_API_CONNECTIONS", config[CONF_MAX_CONNECTIONS])
     cg.add_define("API_MAX_SEND_QUEUE", config[CONF_MAX_SEND_QUEUE])
 
+    actions = config.get(CONF_ACTIONS, [])
+    has_user_actions = bool(actions) or config[CONF_CUSTOM_SERVICES]
     # Set USE_API_USER_DEFINED_ACTIONS if any services are enabled
-    if config.get(CONF_ACTIONS) or config[CONF_CUSTOM_SERVICES]:
+    if has_user_actions:
         cg.add_define("USE_API_USER_DEFINED_ACTIONS")
 
     # Set USE_API_CUSTOM_SERVICES if external components need dynamic service registration
@@ -385,10 +486,17 @@ async def to_code(config: ConfigType) -> None:
     if config[CONF_HOMEASSISTANT_STATES]:
         cg.add_define("USE_API_HOMEASSISTANT_STATES")
 
-    if actions := config.get(CONF_ACTIONS, []):
+    scratch_size = 0
+    if actions:
+        # Metadata is compiled in for every action once any action declares it, because the
+        # string table layout is fixed by the define rather than per action
+        has_metadata = _has_action_metadata(actions)
+        if has_metadata:
+            cg.add_define("USE_API_USER_DEFINED_ACTION_METADATA")
+        interned_strings: dict[str, MockObj] = {}
         # Collect all triggers first, then register all at once with initializer_list
         triggers: list[cg.MockObj] = []
-        for conf in actions:
+        for index, conf in enumerate(actions):
             func_args: list[tuple[MockObj, str]] = []
             service_template_args: list[MockObj] = []  # User service argument types
 
@@ -421,22 +529,23 @@ async def to_code(config: ConfigType) -> None:
                 conf.get(CONF_THEN, [])
             )
 
-            service_arg_names: list[str] = []
             for name, var_ in conf[CONF_VARIABLES].items():
-                if has_non_synchronous and var_ in SERVICE_ARG_FALLBACK_TYPES:
-                    native = SERVICE_ARG_FALLBACK_TYPES[var_]
+                var_type = var_[CONF_TYPE]
+                if has_non_synchronous and var_type in SERVICE_ARG_FALLBACK_TYPES:
+                    native = SERVICE_ARG_FALLBACK_TYPES[var_type]
                 else:
-                    native = SERVICE_ARG_NATIVE_TYPES[var_]
+                    native = SERVICE_ARG_NATIVE_TYPES[var_type]
                 service_template_args.append(native)
                 func_args.append((native, name))
-                service_arg_names.append(name)
+            strings = _action_strings(conf, has_metadata)
+            table = _add_action_strings(index, strings, interned_strings)
+            if CORE.is_esp8266:
+                scratch_size = max(scratch_size, _action_strings_size(strings))
             # Template args: supports_response mode, then user service arg types
             templ = cg.TemplateArguments(supports_response, *service_template_args)
+            # Key is hashed here because the name is not readable at runtime on ESP8266
             trigger = cg.new_Pvariable(
-                conf[CONF_TRIGGER_ID],
-                templ,
-                conf[CONF_ACTION],
-                service_arg_names,
+                conf[CONF_TRIGGER_ID], templ, table, fnv1_hash(conf[CONF_ACTION])
             )
             triggers.append(trigger)
             auto = await automation.build_automation(trigger, func_args, conf)
@@ -458,6 +567,9 @@ async def to_code(config: ConfigType) -> None:
                 cg.add(auto.add_actions([unregister_action]))
         # Register all services at once - single allocation, no reallocations
         cg.add(var.initialize_user_services(triggers))
+    if CORE.is_esp8266 and has_user_actions:
+        # Stack buffer that list-entities copies PROGMEM strings into, sized for the largest action
+        cg.add_define("API_USER_ACTION_STRINGS_SCRATCH_SIZE", max(scratch_size, 1))
 
     if CONF_ON_CLIENT_CONNECTED in config:
         cg.add_define("USE_API_CLIENT_CONNECTED_TRIGGER")

esphome/components/api/api.proto

@@ -1034,6 +1034,8 @@ message ListEntitiesServicesArgument {
   option (ifdef) = "USE_API_USER_DEFINED_ACTIONS";
   string name = 1;
   ServiceArgType type = 2;
+  string description = 3 [(field_ifdef) = "USE_API_USER_DEFINED_ACTION_METADATA"];
+  string example = 4 [(field_ifdef) = "USE_API_USER_DEFINED_ACTION_METADATA"];
 }
 message ListEntitiesServicesResponse {
   option (id) = 41;
@@ -1044,6 +1046,7 @@ message ListEntitiesServicesResponse {
   fixed32 key = 2 [(force) = true];
   repeated ListEntitiesServicesArgument args = 3 [(fixed_vector) = true];
   SupportsResponseType supports_response = 4;
+  string description = 5 [(field_ifdef) = "USE_API_USER_DEFINED_ACTION_METADATA"];
 }
 message ExecuteServiceArgument {
   option (ifdef) = "USE_API_USER_DEFINED_ACTIONS";

esphome/components/api/api_pb2.cpp

@@ -1275,12 +1275,24 @@ uint8_t *ListEntitiesServicesArgument::encode(ProtoWriteBuffer &buffer PROTO_ENC
   uint8_t *__restrict__ pos = buffer.get_pos();
   ProtoEncode::encode_string(pos PROTO_ENCODE_DEBUG_ARG, 1, this->name);
   ProtoEncode::encode_uint32(pos PROTO_ENCODE_DEBUG_ARG, 2, static_cast<uint32_t>(this->type));
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  ProtoEncode::encode_string(pos PROTO_ENCODE_DEBUG_ARG, 3, this->description);
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  ProtoEncode::encode_string(pos PROTO_ENCODE_DEBUG_ARG, 4, this->example);
+#endif
   return pos;
 }
 uint32_t ListEntitiesServicesArgument::calculate_size() const {
   uint32_t size = 0;
   size += ProtoSize::calc_length(1, this->name.size());
   size += this->type ? 2 : 0;
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  size += ProtoSize::calc_length(1, this->description.size());
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  size += ProtoSize::calc_length(1, this->example.size());
+#endif
   return size;
 }
 uint8_t *ListEntitiesServicesResponse::encode(ProtoWriteBuffer &buffer PROTO_ENCODE_DEBUG_PARAM) const {
@@ -1291,6 +1303,9 @@ uint8_t *ListEntitiesServicesResponse::encode(ProtoWriteBuffer &buffer PROTO_ENC
     ProtoEncode::encode_sub_message(pos PROTO_ENCODE_DEBUG_ARG, buffer, 3, it);
   }
   ProtoEncode::encode_uint32(pos PROTO_ENCODE_DEBUG_ARG, 4, static_cast<uint32_t>(this->supports_response));
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  ProtoEncode::encode_string(pos PROTO_ENCODE_DEBUG_ARG, 5, this->description);
+#endif
   return pos;
 }
 uint32_t ListEntitiesServicesResponse::calculate_size() const {
@@ -1303,6 +1318,9 @@ uint32_t ListEntitiesServicesResponse::calculate_size() const {
     }
   }
   size += this->supports_response ? 2 : 0;
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  size += ProtoSize::calc_length(1, this->description.size());
+#endif
   return size;
 }
 bool ExecuteServiceArgument::decode_varint(uint32_t field_id, proto_varint_value_t value) {

esphome/components/api/api_pb2.h

@@ -1317,6 +1317,12 @@ class ListEntitiesServicesArgument final : public ProtoMessage {
  public:
   StringRef name{};
   enums::ServiceArgType type{};
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  StringRef description{};
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  StringRef example{};
+#endif
   uint8_t *encode(ProtoWriteBuffer &buffer PROTO_ENCODE_DEBUG_PARAM) const;
   uint32_t calculate_size() const;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -1328,7 +1334,7 @@ class ListEntitiesServicesArgument final : public ProtoMessage {
 class ListEntitiesServicesResponse final : public ProtoMessage {
  public:
   static constexpr uint16_t MESSAGE_TYPE = 41;
-  static constexpr uint8_t ESTIMATED_SIZE = 50;
+  static constexpr uint8_t ESTIMATED_SIZE = 59;
 #ifdef HAS_PROTO_MESSAGE_DUMP
   const LogString *message_name() const override { return LOG_STR("list_entities_services_response"); }
 #endif
@@ -1336,6 +1342,9 @@ class ListEntitiesServicesResponse final : public ProtoMessage {
   uint32_t key{0};
   FixedVector<ListEntitiesServicesArgument> args{};
   enums::SupportsResponseType supports_response{};
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  StringRef description{};
+#endif
   uint8_t *encode(ProtoWriteBuffer &buffer PROTO_ENCODE_DEBUG_PARAM) const;
   uint32_t calculate_size() const;
 #ifdef HAS_PROTO_MESSAGE_DUMP

esphome/components/api/api_pb2_dump.cpp

@@ -1500,6 +1500,12 @@ const char *ListEntitiesServicesArgument::dump_to(DumpBuffer &out) const {
   MessageDumpHelper helper(out, ESPHOME_PSTR("ListEntitiesServicesArgument"));
   dump_field(out, ESPHOME_PSTR("name"), this->name);
   dump_field(out, ESPHOME_PSTR("type"), static_cast<enums::ServiceArgType>(this->type));
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  dump_field(out, ESPHOME_PSTR("description"), this->description);
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  dump_field(out, ESPHOME_PSTR("example"), this->example);
+#endif
   return out.c_str();
 }
 const char *ListEntitiesServicesResponse::dump_to(DumpBuffer &out) const {
@@ -1512,6 +1518,9 @@ const char *ListEntitiesServicesResponse::dump_to(DumpBuffer &out) const {
     out.append("\n");
   }
   dump_field(out, ESPHOME_PSTR("supports_response"), static_cast<enums::SupportsResponseType>(this->supports_response));
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  dump_field(out, ESPHOME_PSTR("description"), this->description);
+#endif
   return out.c_str();
 }
 const char *ExecuteServiceArgument::dump_to(DumpBuffer &out) const {

esphome/components/api/list_entities.cpp

@@ -99,7 +99,8 @@ ListEntitiesIterator::ListEntitiesIterator(APIConnection *client) : client_(clie
 static constexpr uint8_t SERVICE_YIELD_INTERVAL = 3;
 
 bool ListEntitiesIterator::on_service(UserServiceDescriptor *service) {
-  auto resp = service->encode_list_service_response();
+  UserActionScratch scratch;
+  auto resp = service->encode_list_service_response(scratch);
   if (!this->client_->send_message(resp))
     return false;
   // at_ is this service's index

esphome/components/api/user_services.cpp

@@ -1,9 +1,52 @@
 #include "user_services.h"
+#include "esphome/core/hal.h"
 #include "esphome/core/log.h"
 #include "esphome/core/string_ref.h"
 
 namespace esphome::api {
 
+StringRef UserServiceStatic::str_(size_t idx, std::span<char> &scratch) const {
+  const char *s = progmem_read_ptr(&this->strings_[idx]);
+  if (s == nullptr)
+    return {};
+#ifdef USE_ESP8266
+  // Codegen sizes the scratch buffer for the largest service; the bound only guards other callers
+  if (scratch.empty())
+    return {};
+  size_t len = strnlen_P(s, scratch.size() - 1);
+  progmem_memcpy(scratch.data(), s, len);
+  scratch[len] = '\0';
+  StringRef ref(scratch.data(), len);
+  scratch = scratch.subspan(len + 1);
+  return ref;
+#else
+  return StringRef(s);
+#endif
+}
+
+ListEntitiesServicesResponse UserServiceStatic::encode_list_service_response_(
+    std::span<const enums::ServiceArgType> arg_types, std::span<char> scratch) const {
+  ListEntitiesServicesResponse msg;
+  msg.name = this->str_(0, scratch);
+  msg.key = this->key_;
+  msg.supports_response = this->supports_response_;
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+  msg.description = this->str_(1, scratch);
+#endif
+  msg.args.init(arg_types.size());
+  for (size_t i = 0; i < arg_types.size(); i++) {
+    size_t base = USER_ACTION_HEADER_STRINGS + i * USER_ACTION_ARG_STRINGS;
+    auto &arg = msg.args.emplace_back();
+    arg.type = arg_types[i];
+    arg.name = this->str_(base, scratch);
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+    arg.description = this->str_(base + 1, scratch);
+    arg.example = this->str_(base + 2, scratch);
+#endif
+  }
+  return msg;
+}
+
 template<> bool get_execute_arg_value<bool>(const ExecuteServiceArgument &arg) { return arg.bool_; }
 template<> int32_t get_execute_arg_value<int32_t>(const ExecuteServiceArgument &arg) {
   if (arg.legacy_int != 0)

esphome/components/api/user_services.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <span>
 #include <tuple>
 #include <utility>
 #include <vector>
@@ -19,7 +20,9 @@ class APIServer;
 
 class UserServiceDescriptor {
  public:
-  virtual ListEntitiesServicesResponse encode_list_service_response() = 0;
+  /// Build the list-entities message. On ESP8266 the strings live in PROGMEM and are copied into
+  /// `scratch`, so the returned message is only valid while `scratch` is; other platforms ignore it.
+  virtual ListEntitiesServicesResponse encode_list_service_response(std::span<char> scratch) = 0;
 
   virtual bool execute_service(const ExecuteServiceRequest &req) = 0;
 #ifdef USE_API_USER_DEFINED_ACTION_RESPONSES
@@ -34,29 +37,51 @@ template<typename T> T get_execute_arg_value(const ExecuteServiceArgument &arg);
 
 template<typename T> enums::ServiceArgType to_service_arg_type();
 
-// Base class for YAML-defined services (most common case)
-// Stores only pointers to string literals in flash - no heap allocation
-template<typename... Ts> class UserServiceBase : public UserServiceDescriptor {
- public:
-  UserServiceBase(const char *name, const std::array<const char *, sizeof...(Ts)> &arg_names,
-                  enums::SupportsResponseType supports_response = enums::SUPPORTS_RESPONSE_NONE)
-      : name_(name), arg_names_(arg_names), supports_response_(supports_response) {
-    this->key_ = fnv1_hash(name);
-  }
+// Scratch buffer list-entities hands to encode_list_service_response(); only ESP8266 copies into it
+#ifdef USE_ESP8266
+using UserActionScratch = std::array<char, API_USER_ACTION_STRINGS_SCRATCH_SIZE>;
+#else
+using UserActionScratch = std::array<char, 0>;
+#endif
 
-  ListEntitiesServicesResponse encode_list_service_response() override {
-    ListEntitiesServicesResponse msg;
-    msg.name = StringRef(this->name_);
-    msg.key = this->key_;
-    msg.supports_response = this->supports_response_;
+// Non-template base for YAML-defined services so the list-entities encoder is compiled once.
+// All strings live in one PROGMEM pointer table emitted by codegen (see _action_strings in
+// __init__.py), so each service costs a single pointer of RAM. Layout: the action name, then
+// each argument name; with USE_API_USER_DEFINED_ACTION_METADATA the action description follows
+// the name and every argument is (name, description, example). Unset metadata is nullptr.
+#ifdef USE_API_USER_DEFINED_ACTION_METADATA
+static constexpr size_t USER_ACTION_HEADER_STRINGS = 2;
+static constexpr size_t USER_ACTION_ARG_STRINGS = 3;
+#else
+static constexpr size_t USER_ACTION_HEADER_STRINGS = 1;
+static constexpr size_t USER_ACTION_ARG_STRINGS = 1;
+#endif
+class UserServiceStatic : public UserServiceDescriptor {
+ public:
+  UserServiceStatic(const char *const *strings, uint32_t key,
+                    enums::SupportsResponseType supports_response = enums::SUPPORTS_RESPONSE_NONE)
+      : strings_(strings), key_(key), supports_response_(supports_response) {}
+
+ protected:
+  ListEntitiesServicesResponse encode_list_service_response_(std::span<const enums::ServiceArgType> arg_types,
+                                                             std::span<char> scratch) const;
+  /// Reference table entry `idx`; nullptr gives an empty StringRef.
+  /// On ESP8266 the bytes are copied out of PROGMEM into `scratch` with a terminator, and the span
+  /// is advanced past the copy.
+  StringRef str_(size_t idx, std::span<char> &scratch) const;
+
+  const char *const *strings_;  // PROGMEM pointer table, read with progmem_read_ptr()
+  uint32_t key_;
+  enums::SupportsResponseType supports_response_;
+};
+
+template<typename... Ts> class UserServiceBase : public UserServiceStatic {
+ public:
+  using UserServiceStatic::UserServiceStatic;
+
+  ListEntitiesServicesResponse encode_list_service_response(std::span<char> scratch) override {
     std::array<enums::ServiceArgType, sizeof...(Ts)> arg_types = {to_service_arg_type<Ts>()...};
-    msg.args.init(sizeof...(Ts));
-    for (size_t i = 0; i < sizeof...(Ts); i++) {
-      auto &arg = msg.args.emplace_back();
-      arg.type = arg_types[i];
-      arg.name = StringRef(this->arg_names_[i]);
-    }
-    return msg;
+    return this->encode_list_service_response_(arg_types, scratch);
   }
 
   bool execute_service(const ExecuteServiceRequest &req) override {
@@ -89,12 +114,6 @@ template<typename... Ts> class UserServiceBase : public UserServiceDescriptor {
   void execute_(const ArgsContainer &args, uint32_t call_id, bool return_response, std::index_sequence<S...> /*type*/) {
     this->execute(call_id, return_response, (get_execute_arg_value<Ts>(args[S]))...);
   }
-
-  // Pointers to string literals in flash - no heap allocation
-  const char *name_;
-  std::array<const char *, sizeof...(Ts)> arg_names_;
-  uint32_t key_{0};
-  enums::SupportsResponseType supports_response_{enums::SUPPORTS_RESPONSE_NONE};
 };
 
 // Separate class for custom_api_device services (rare case)
@@ -106,7 +125,7 @@ template<typename... Ts> class UserServiceDynamic : public UserServiceDescriptor
     this->key_ = fnv1_hash(this->name_.c_str());
   }
 
-  ListEntitiesServicesResponse encode_list_service_response() override {
+  ListEntitiesServicesResponse encode_list_service_response(std::span<char> /*scratch*/) override {
     ListEntitiesServicesResponse msg;
     msg.name = StringRef(this->name_);
     msg.key = this->key_;
@@ -167,8 +186,8 @@ template<typename... Ts>
 class UserServiceTrigger<enums::SUPPORTS_RESPONSE_NONE, Ts...> final : public UserServiceBase<Ts...>,
                                                                        public Trigger<Ts...> {
  public:
-  UserServiceTrigger(const char *name, const std::array<const char *, sizeof...(Ts)> &arg_names)
-      : UserServiceBase<Ts...>(name, arg_names, enums::SUPPORTS_RESPONSE_NONE) {}
+  UserServiceTrigger(const char *const *strings, uint32_t key)
+      : UserServiceBase<Ts...>(strings, key, enums::SUPPORTS_RESPONSE_NONE) {}
 
  protected:
   void execute(uint32_t /*call_id*/, bool /*return_response*/, Ts... x) override { this->trigger(x...); }
@@ -179,8 +198,8 @@ template<typename... Ts>
 class UserServiceTrigger<enums::SUPPORTS_RESPONSE_OPTIONAL, Ts...> final : public UserServiceBase<Ts...>,
                                                                            public Trigger<uint32_t, bool, Ts...> {
  public:
-  UserServiceTrigger(const char *name, const std::array<const char *, sizeof...(Ts)> &arg_names)
-      : UserServiceBase<Ts...>(name, arg_names, enums::SUPPORTS_RESPONSE_OPTIONAL) {}
+  UserServiceTrigger(const char *const *strings, uint32_t key)
+      : UserServiceBase<Ts...>(strings, key, enums::SUPPORTS_RESPONSE_OPTIONAL) {}
 
  protected:
   void execute(uint32_t call_id, bool return_response, Ts... x) override {
@@ -193,8 +212,8 @@ template<typename... Ts>
 class UserServiceTrigger<enums::SUPPORTS_RESPONSE_ONLY, Ts...> final : public UserServiceBase<Ts...>,
                                                                        public Trigger<uint32_t, Ts...> {
  public:
-  UserServiceTrigger(const char *name, const std::array<const char *, sizeof...(Ts)> &arg_names)
-      : UserServiceBase<Ts...>(name, arg_names, enums::SUPPORTS_RESPONSE_ONLY) {}
+  UserServiceTrigger(const char *const *strings, uint32_t key)
+      : UserServiceBase<Ts...>(strings, key, enums::SUPPORTS_RESPONSE_ONLY) {}
 
  protected:
   void execute(uint32_t call_id, bool /*return_response*/, Ts... x) override { this->trigger(call_id, x...); }
@@ -205,8 +224,8 @@ template<typename... Ts>
 class UserServiceTrigger<enums::SUPPORTS_RESPONSE_STATUS, Ts...> final : public UserServiceBase<Ts...>,
                                                                          public Trigger<uint32_t, Ts...> {
  public:
-  UserServiceTrigger(const char *name, const std::array<const char *, sizeof...(Ts)> &arg_names)
-      : UserServiceBase<Ts...>(name, arg_names, enums::SUPPORTS_RESPONSE_STATUS) {}
+  UserServiceTrigger(const char *const *strings, uint32_t key)
+      : UserServiceBase<Ts...>(strings, key, enums::SUPPORTS_RESPONSE_STATUS) {}
 
  protected:
   void execute(uint32_t call_id, bool /*return_response*/, Ts... x) override { this->trigger(call_id, x...); }

esphome/components/const/__init__.py

@@ -16,6 +16,7 @@ CONF_CO2_EQUIVALENT = "co2_equivalent"
 CONF_COLOR_DEPTH = "color_depth"
 CONF_CRC_ENABLE = "crc_enable"
 CONF_DATA_BITS = "data_bits"
+CONF_DESCRIPTION = "description"
 CONF_DRAW_ROUNDING = "draw_rounding"
 CONF_ENABLE_OTA_DOWNGRADE_PROTECTION = "enable_ota_downgrade_protection"
 CONF_ENABLED = "enabled"

esphome/components/esp32/__init__.py

@@ -214,11 +214,13 @@ COMPILER_OPTIMIZATIONS = {
 # builds that need them.
 DEFAULT_EXCLUDED_IDF_COMPONENTS = (
     "app_trace",  # CPU trace/SystemView support - unused by ESPHome
+    "bt",  # Bluetooth stack - re-included by request_bluetooth(); its REQUIRES pulls the WiFi stack back
     "cmock",  # Unit testing mock framework - ESPHome doesn't use IDF's testing
     "console",  # Console REPL - unused by ESPHome; espressif/mdns pulls it back when configured
     "driver",  # Legacy driver shim - only needed by esp32_touch, esp32_can for legacy headers
     "esp-tls",  # TLS wrapper - re-included by http_request, mqtt, web_server_idf
     "esp_adc",  # ADC driver - only needed by adc component
+    "esp_coex",  # WiFi/BT coexistence - re-included by esp32_ble_tracker, zigbee; esp_wifi/bt pull it back
     "esp_driver_cam",  # Camera driver - the esp32-camera managed component pulls it back
     "esp_driver_dac",  # DAC driver - only needed by esp32_dac component
     "esp_driver_gptimer",  # General purpose timer - re-included by ac_dimmer, opentherm, Arduino BLE libs
@@ -236,6 +238,7 @@ DEFAULT_EXCLUDED_IDF_COMPONENTS = (
     "esp_driver_twai",  # TWAI/CAN driver - only needed by esp32_can component
     "esp_eth",  # Ethernet driver - only needed by ethernet component
     "esp_gdbstub",  # GDB stub panic handler - unused by ESPHome; bt pulls it back
+    "esp_hal_ieee802154",  # 802.15.4 HAL - ieee802154 pulls it back
     "esp_hid",  # HID host/device support - ESPHome doesn't implement HID functionality
     "esp_http_client",  # HTTP client - only needed by http_request component
     "esp_http_server",  # HTTP server - re-included by web_server_idf, esp32_camera_web_server
@@ -243,8 +246,11 @@ DEFAULT_EXCLUDED_IDF_COMPONENTS = (
     "esp_https_server",  # HTTPS server - ESPHome has its own web server
     "esp_lcd",  # LCD controller drivers - only needed by display component
     "esp_local_ctrl",  # Local control over HTTPS/BLE - ESPHome has native API
+    "esp_phy",  # RF PHY - re-included by internal_temperature on the original ESP32; esp_wifi/bt/ieee802154 pull it back
+    "esp_wifi",  # WiFi stack - re-included by request_wifi(), espnow; bt pulls it back for BLE builds
     "espcoredump",  # Core dump support - ESPHome has its own debug component
     "fatfs",  # FAT filesystem - ESPHome doesn't use filesystem storage
+    "ieee802154",  # 802.15.4 radio - IDF openthread and the Zigbee libs pull it back
     "json",  # cJSON library - ESPHome uses ArduinoJson instead
     "mqtt",  # ESP-IDF MQTT library - ESPHome has its own MQTT implementation
     "nvs_sec_provider",  # NVS encryption key provider - re-included when CONFIG_NVS_ENCRYPTION is set
@@ -260,6 +266,7 @@ DEFAULT_EXCLUDED_IDF_COMPONENTS = (
     "unity",  # Unit testing framework - ESPHome doesn't use IDF's testing
     "wear_levelling",  # Flash wear levelling for fatfs - unused since fatfs unused
     "wifi_provisioning",  # WiFi provisioning - ESPHome uses its own improv implementation
+    "wpa_supplicant",  # WPA supplicant - re-included by request_wifi() for esp_eap_client.h
 )
 
 # Additional IDF managed components to exclude for Arduino framework builds
@@ -709,6 +716,9 @@ def request_wifi(ap: bool = False) -> None:
     net.wifi = True
     if ap:
         net.wifi_ap = True
+    include_builtin_idf_component("esp_wifi")
+    # wifi_component.cpp includes esp_eap_client.h/esp_wpa2.h
+    include_builtin_idf_component("wpa_supplicant")
 
 
 def request_ethernet() -> None:
@@ -720,11 +730,14 @@ def request_bluetooth() -> None:
     """Request the Bluetooth controller."""
     net = _network_sdkconfig()
     net.bluetooth = True
+    include_builtin_idf_component("bt")
 
 
 def request_software_coexistence() -> None:
     """Request WiFi/BT software coexistence (only valid alongside WiFi)."""
     _network_sdkconfig().software_coexistence = True
+    # Callers include esp_coexist.h directly.
+    include_builtin_idf_component("esp_coex")
 
 
 def add_idf_component(
@@ -2304,6 +2317,8 @@ async def _reconcile_network_sdkconfig() -> None:
 
     # WiFi stack: disable only when Ethernet is present and WiFi is not. WiFi
     # relies on the IDF default (enabled), so it is never written True here.
+    # esp_wifi is excluded by default on IDF, so this only matters for Arduino
+    # or when bt pulls it back.
     wifi_disabled = net.ethernet and not net.wifi
     if wifi_disabled:
         set_idf_sdkconfig_default("CONFIG_ESP_WIFI_ENABLED", False)
@@ -3234,7 +3249,13 @@ def _write_sdkconfig():
     if write_file_if_changed(internal_path, contents):
         # internal changed, update real one
         write_file_if_changed(sdk_path, contents)
-        clean_build(clear_pio_cache=False)
+        if not CORE.using_toolchain_esp_idf:
+            # PIO's dependency tracking under-declares sdkconfig inputs
+            # (ldgen, linker scripts); without a clean the image can be
+            # unbootable (esphome#15336). The esp-idf toolchain tracks
+            # sdkconfig via IDF's cmake and has_outdated_files(), so a
+            # reconfigure suffices there; everything else fails safe.
+            clean_build(clear_pio_cache=False)
 
 
 def _write_idf_component_yml():

esphome/components/espnow/__init__.py

@@ -155,6 +155,11 @@ async def to_code(config: ConfigType) -> None:
     cg.add_define("USE_ESPNOW")
     cg.add_define("USE_ESPNOW_MAX_PAYLOAD_SIZE", config[CONF_MAX_PAYLOAD_SIZE])
 
+    if CORE.is_esp32:
+        from esphome.components.esp32 import include_builtin_idf_component
+
+        include_builtin_idf_component("esp_wifi")
+
     if CONF_WIFI in CORE.config:
         # Track the Wi-Fi channel via connect events instead of polling every loop
         wifi.request_wifi_connect_state_listener()

esphome/components/growatt_solar/growatt_solar.cpp

@@ -1,105 +1,68 @@
 #include "growatt_solar.h"
-#include "esphome/core/application.h"
-#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 namespace esphome::growatt_solar {
 
+namespace helpers = modbus::helpers;
+
 static const char *const TAG = "growatt_solar";
 
 static const uint8_t MODBUS_REGISTER_COUNT[] = {33, 95};  // indexed with enum GrowattProtocolVersion
 
-void GrowattSolar::loop() {
-  // If update() was unable to send we retry until we can send.
-  if (!this->waiting_to_update_)
-    return;
-  update();
-}
+void GrowattSolar::update() { this->read_input_registers(0, MODBUS_REGISTER_COUNT[this->protocol_version_]); }
 
-void GrowattSolar::update() {
-  // If our last send has had no reply yet, and it wasn't that long ago, do nothing.
-  const uint32_t now = App.get_loop_component_start_time();
-  if (now - this->last_send_ < this->get_update_interval() / 2) {
-    return;
-  }
-
-  // The bus might be slow, or there might be other devices, or other components might be talking to our device.
-  if (!this->ready_for_immediate_send()) {
-    this->waiting_to_update_ = true;
-    return;
-  }
-
-  this->waiting_to_update_ = false;
-  this->read_input_registers(0, MODBUS_REGISTER_COUNT[this->protocol_version_]);
-  this->last_send_ = millis();
-}
-
-void GrowattSolar::on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) {
-  auto data = modbus::helpers::server_pdu_payload(response_pdu);
-  // Other components might be sending commands to our device. But we don't get called with enough
-  // context to know what is what. So if we didn't do a send, we ignore the data.
-  if (!this->last_send_)
-    return;
-  this->last_send_ = 0;
-
-  // Also ignore the data if the message is too short. Otherwise we will publish invalid values.
-  if (data.size() < MODBUS_REGISTER_COUNT[this->protocol_version_] * 2)
+void GrowattSolar::on_read_input_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                                           modbus::ResponseStatus status) {
+  if (!modbus::succeeded(status))
     return;
 
-  auto publish_1_reg_sensor_state = [&](sensor::Sensor *sensor, size_t i, float unit) -> void {
+  // Publish a sensor if its register(s) are in this response; skipping absent registers keeps this
+  // correct for any read range, so the poll may be split into multiple requests.
+  auto publish_1_reg_sensor_state = [&](sensor::Sensor *sensor, uint16_t reg, float unit) -> void {
     if (sensor == nullptr)
       return;
-    float value = encode_uint16(data[i * 2], data[i * 2 + 1]) * unit;
-    sensor->publish_state(value);
+    if (auto value = helpers::value_at<helpers::SensorValueType::U_WORD>(registers, start_address, reg))
+      sensor->publish_state(*value * unit);
   };
 
-  auto publish_2_reg_sensor_state = [&](sensor::Sensor *sensor, size_t reg1, size_t reg2, float unit) -> void {
-    float value = ((encode_uint16(data[reg1 * 2], data[reg1 * 2 + 1]) << 16) +
-                   encode_uint16(data[reg2 * 2], data[reg2 * 2 + 1])) *
-                  unit;
-    if (sensor != nullptr)
-      sensor->publish_state(value);
+  auto publish_2_reg_sensor_state = [&](sensor::Sensor *sensor, uint16_t reg, float unit) -> void {
+    if (sensor == nullptr)
+      return;
+    if (auto value = helpers::value_at<helpers::SensorValueType::U_DWORD>(registers, start_address, reg))
+      sensor->publish_state(*value * unit);
   };
 
   switch (this->protocol_version_) {
     case RTU: {
       publish_1_reg_sensor_state(this->inverter_status_, RTU_INVERTER_STATUS, 1);
 
-      publish_2_reg_sensor_state(this->pv_active_power_sensor_, RTU_PV_ACTIVE_POWER, RTU_PV_ACTIVE_POWER + 1,
-                                 ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->pv_active_power_sensor_, RTU_PV_ACTIVE_POWER, ONE_DEC_UNIT);
 
       publish_1_reg_sensor_state(this->pvs_[0].voltage_sensor_, RTU_PV1_VOLTAGE, ONE_DEC_UNIT);
       publish_1_reg_sensor_state(this->pvs_[0].current_sensor_, RTU_PV1_CURRENT, ONE_DEC_UNIT);
-      publish_2_reg_sensor_state(this->pvs_[0].active_power_sensor_, RTU_PV1_ACTIVE_POWER, RTU_PV1_ACTIVE_POWER + 1,
-                                 ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->pvs_[0].active_power_sensor_, RTU_PV1_ACTIVE_POWER, ONE_DEC_UNIT);
 
       publish_1_reg_sensor_state(this->pvs_[1].voltage_sensor_, RTU_PV2_VOLTAGE, ONE_DEC_UNIT);
       publish_1_reg_sensor_state(this->pvs_[1].current_sensor_, RTU_PV2_CURRENT, ONE_DEC_UNIT);
-      publish_2_reg_sensor_state(this->pvs_[1].active_power_sensor_, RTU_PV2_ACTIVE_POWER, RTU_PV2_ACTIVE_POWER + 1,
-                                 ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->pvs_[1].active_power_sensor_, RTU_PV2_ACTIVE_POWER, ONE_DEC_UNIT);
 
-      publish_2_reg_sensor_state(this->grid_active_power_sensor_, RTU_GRID_ACTIVE_POWER, RTU_GRID_ACTIVE_POWER + 1,
-                                 ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->grid_active_power_sensor_, RTU_GRID_ACTIVE_POWER, ONE_DEC_UNIT);
       publish_1_reg_sensor_state(this->grid_frequency_sensor_, RTU_GRID_FREQUENCY, TWO_DEC_UNIT);
 
       publish_1_reg_sensor_state(this->phases_[0].voltage_sensor_, RTU_PHASE1_VOLTAGE, ONE_DEC_UNIT);
       publish_1_reg_sensor_state(this->phases_[0].current_sensor_, RTU_PHASE1_CURRENT, ONE_DEC_UNIT);
-      publish_2_reg_sensor_state(this->phases_[0].active_power_sensor_, RTU_PHASE1_ACTIVE_POWER,
-                                 RTU_PHASE1_ACTIVE_POWER + 1, ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->phases_[0].active_power_sensor_, RTU_PHASE1_ACTIVE_POWER, ONE_DEC_UNIT);
 
       publish_1_reg_sensor_state(this->phases_[1].voltage_sensor_, RTU_PHASE2_VOLTAGE, ONE_DEC_UNIT);
       publish_1_reg_sensor_state(this->phases_[1].current_sensor_, RTU_PHASE2_CURRENT, ONE_DEC_UNIT);
-      publish_2_reg_sensor_state(this->phases_[1].active_power_sensor_, RTU_PHASE2_ACTIVE_POWER,
-                                 RTU_PHASE2_ACTIVE_POWER + 1, ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->phases_[1].active_power_sensor_, RTU_PHASE2_ACTIVE_POWER, ONE_DEC_UNIT);
 
       publish_1_reg_sensor_state(this->phases_[2].voltage_sensor_, RTU_PHASE3_VOLTAGE, ONE_DEC_UNIT);
       publish_1_reg_sensor_state(this->phases_[2].current_sensor_, RTU_PHASE3_CURRENT, ONE_DEC_UNIT);
-      publish_2_reg_sensor_state(this->phases_[2].active_power_sensor_, RTU_PHASE3_ACTIVE_POWER,
-                                 RTU_PHASE3_ACTIVE_POWER + 1, ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->phases_[2].active_power_sensor_, RTU_PHASE3_ACTIVE_POWER, ONE_DEC_UNIT);
 
-      publish_2_reg_sensor_state(this->today_production_, RTU_TODAY_PRODUCTION, RTU_TODAY_PRODUCTION + 1, ONE_DEC_UNIT);
-      publish_2_reg_sensor_state(this->total_energy_production_, RTU_TOTAL_ENERGY_PRODUCTION,
-                                 RTU_TOTAL_ENERGY_PRODUCTION + 1, ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->today_production_, RTU_TODAY_PRODUCTION, ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->total_energy_production_, RTU_TOTAL_ENERGY_PRODUCTION, ONE_DEC_UNIT);
 
       publish_1_reg_sensor_state(this->inverter_module_temp_, RTU_INVERTER_MODULE_TEMP, ONE_DEC_UNIT);
       break;
@@ -107,42 +70,33 @@ void GrowattSolar::on_response(std::span<const uint8_t> request_pdu, std::span<c
     case RTU2: {
       publish_1_reg_sensor_state(this->inverter_status_, RTU2_INVERTER_STATUS, 1);
 
-      publish_2_reg_sensor_state(this->pv_active_power_sensor_, RTU2_PV_ACTIVE_POWER, RTU2_PV_ACTIVE_POWER + 1,
-                                 ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->pv_active_power_sensor_, RTU2_PV_ACTIVE_POWER, ONE_DEC_UNIT);
 
       publish_1_reg_sensor_state(this->pvs_[0].voltage_sensor_, RTU2_PV1_VOLTAGE, ONE_DEC_UNIT);
       publish_1_reg_sensor_state(this->pvs_[0].current_sensor_, RTU2_PV1_CURRENT, ONE_DEC_UNIT);
-      publish_2_reg_sensor_state(this->pvs_[0].active_power_sensor_, RTU2_PV1_ACTIVE_POWER, RTU2_PV1_ACTIVE_POWER + 1,
-                                 ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->pvs_[0].active_power_sensor_, RTU2_PV1_ACTIVE_POWER, ONE_DEC_UNIT);
 
       publish_1_reg_sensor_state(this->pvs_[1].voltage_sensor_, RTU2_PV2_VOLTAGE, ONE_DEC_UNIT);
       publish_1_reg_sensor_state(this->pvs_[1].current_sensor_, RTU2_PV2_CURRENT, ONE_DEC_UNIT);
-      publish_2_reg_sensor_state(this->pvs_[1].active_power_sensor_, RTU2_PV2_ACTIVE_POWER, RTU2_PV2_ACTIVE_POWER + 1,
-                                 ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->pvs_[1].active_power_sensor_, RTU2_PV2_ACTIVE_POWER, ONE_DEC_UNIT);
 
-      publish_2_reg_sensor_state(this->grid_active_power_sensor_, RTU2_GRID_ACTIVE_POWER, RTU2_GRID_ACTIVE_POWER + 1,
-                                 ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->grid_active_power_sensor_, RTU2_GRID_ACTIVE_POWER, ONE_DEC_UNIT);
       publish_1_reg_sensor_state(this->grid_frequency_sensor_, RTU2_GRID_FREQUENCY, TWO_DEC_UNIT);
 
       publish_1_reg_sensor_state(this->phases_[0].voltage_sensor_, RTU2_PHASE1_VOLTAGE, ONE_DEC_UNIT);
       publish_1_reg_sensor_state(this->phases_[0].current_sensor_, RTU2_PHASE1_CURRENT, ONE_DEC_UNIT);
-      publish_2_reg_sensor_state(this->phases_[0].active_power_sensor_, RTU2_PHASE1_ACTIVE_POWER,
-                                 RTU2_PHASE1_ACTIVE_POWER + 1, ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->phases_[0].active_power_sensor_, RTU2_PHASE1_ACTIVE_POWER, ONE_DEC_UNIT);
 
       publish_1_reg_sensor_state(this->phases_[1].voltage_sensor_, RTU2_PHASE2_VOLTAGE, ONE_DEC_UNIT);
       publish_1_reg_sensor_state(this->phases_[1].current_sensor_, RTU2_PHASE2_CURRENT, ONE_DEC_UNIT);
-      publish_2_reg_sensor_state(this->phases_[1].active_power_sensor_, RTU2_PHASE2_ACTIVE_POWER,
-                                 RTU2_PHASE2_ACTIVE_POWER + 1, ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->phases_[1].active_power_sensor_, RTU2_PHASE2_ACTIVE_POWER, ONE_DEC_UNIT);
 
       publish_1_reg_sensor_state(this->phases_[2].voltage_sensor_, RTU2_PHASE3_VOLTAGE, ONE_DEC_UNIT);
       publish_1_reg_sensor_state(this->phases_[2].current_sensor_, RTU2_PHASE3_CURRENT, ONE_DEC_UNIT);
-      publish_2_reg_sensor_state(this->phases_[2].active_power_sensor_, RTU2_PHASE3_ACTIVE_POWER,
-                                 RTU2_PHASE3_ACTIVE_POWER + 1, ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->phases_[2].active_power_sensor_, RTU2_PHASE3_ACTIVE_POWER, ONE_DEC_UNIT);
 
-      publish_2_reg_sensor_state(this->today_production_, RTU2_TODAY_PRODUCTION, RTU2_TODAY_PRODUCTION + 1,
-                                 ONE_DEC_UNIT);
-      publish_2_reg_sensor_state(this->total_energy_production_, RTU2_TOTAL_ENERGY_PRODUCTION,
-                                 RTU2_TOTAL_ENERGY_PRODUCTION + 1, ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->today_production_, RTU2_TODAY_PRODUCTION, ONE_DEC_UNIT);
+      publish_2_reg_sensor_state(this->total_energy_production_, RTU2_TOTAL_ENERGY_PRODUCTION, ONE_DEC_UNIT);
 
       publish_1_reg_sensor_state(this->inverter_module_temp_, RTU2_INVERTER_MODULE_TEMP, ONE_DEC_UNIT);
       break;

esphome/components/growatt_solar/growatt_solar.h

@@ -17,59 +17,59 @@ enum GrowattProtocolVersion {
 };
 
 // Register addresses for the RTU protocol.
-constexpr size_t RTU_INVERTER_STATUS = 0;           // length = 1
-constexpr size_t RTU_PV_ACTIVE_POWER = 1;           // length = 2
-constexpr size_t RTU_PV1_VOLTAGE = 3;               // length = 1
-constexpr size_t RTU_PV1_CURRENT = 4;               // length = 1
-constexpr size_t RTU_PV1_ACTIVE_POWER = 5;          // length = 2
-constexpr size_t RTU_PV2_VOLTAGE = 7;               // length = 1
-constexpr size_t RTU_PV2_CURRENT = 8;               // length = 1
-constexpr size_t RTU_PV2_ACTIVE_POWER = 9;          // length = 2
-constexpr size_t RTU_GRID_ACTIVE_POWER = 11;        // length = 2
-constexpr size_t RTU_GRID_FREQUENCY = 13;           // length = 1
-constexpr size_t RTU_PHASE1_VOLTAGE = 14;           // length = 1
-constexpr size_t RTU_PHASE1_CURRENT = 15;           // length = 1
-constexpr size_t RTU_PHASE1_ACTIVE_POWER = 16;      // length = 2
-constexpr size_t RTU_PHASE2_VOLTAGE = 18;           // length = 1
-constexpr size_t RTU_PHASE2_CURRENT = 19;           // length = 1
-constexpr size_t RTU_PHASE2_ACTIVE_POWER = 20;      // length = 2
-constexpr size_t RTU_PHASE3_VOLTAGE = 22;           // length = 1
-constexpr size_t RTU_PHASE3_CURRENT = 23;           // length = 1
-constexpr size_t RTU_PHASE3_ACTIVE_POWER = 24;      // length = 2
-constexpr size_t RTU_TODAY_PRODUCTION = 26;         // length = 2
-constexpr size_t RTU_TOTAL_ENERGY_PRODUCTION = 28;  // length = 2
-constexpr size_t RTU_INVERTER_MODULE_TEMP = 32;     // length = 1
+constexpr uint16_t RTU_INVERTER_STATUS = 0;           // length = 1
+constexpr uint16_t RTU_PV_ACTIVE_POWER = 1;           // length = 2
+constexpr uint16_t RTU_PV1_VOLTAGE = 3;               // length = 1
+constexpr uint16_t RTU_PV1_CURRENT = 4;               // length = 1
+constexpr uint16_t RTU_PV1_ACTIVE_POWER = 5;          // length = 2
+constexpr uint16_t RTU_PV2_VOLTAGE = 7;               // length = 1
+constexpr uint16_t RTU_PV2_CURRENT = 8;               // length = 1
+constexpr uint16_t RTU_PV2_ACTIVE_POWER = 9;          // length = 2
+constexpr uint16_t RTU_GRID_ACTIVE_POWER = 11;        // length = 2
+constexpr uint16_t RTU_GRID_FREQUENCY = 13;           // length = 1
+constexpr uint16_t RTU_PHASE1_VOLTAGE = 14;           // length = 1
+constexpr uint16_t RTU_PHASE1_CURRENT = 15;           // length = 1
+constexpr uint16_t RTU_PHASE1_ACTIVE_POWER = 16;      // length = 2
+constexpr uint16_t RTU_PHASE2_VOLTAGE = 18;           // length = 1
+constexpr uint16_t RTU_PHASE2_CURRENT = 19;           // length = 1
+constexpr uint16_t RTU_PHASE2_ACTIVE_POWER = 20;      // length = 2
+constexpr uint16_t RTU_PHASE3_VOLTAGE = 22;           // length = 1
+constexpr uint16_t RTU_PHASE3_CURRENT = 23;           // length = 1
+constexpr uint16_t RTU_PHASE3_ACTIVE_POWER = 24;      // length = 2
+constexpr uint16_t RTU_TODAY_PRODUCTION = 26;         // length = 2
+constexpr uint16_t RTU_TOTAL_ENERGY_PRODUCTION = 28;  // length = 2
+constexpr uint16_t RTU_INVERTER_MODULE_TEMP = 32;     // length = 1
 
 // Input register addresses for the RTU2 protocol as described
 // in the "GROWATT INVERTER MODBUS PROTOCOL_II V1.39" document.
-constexpr size_t RTU2_INVERTER_STATUS = 0;           // length = 1
-constexpr size_t RTU2_PV_ACTIVE_POWER = 1;           // length = 2
-constexpr size_t RTU2_PV1_VOLTAGE = 3;               // length = 1
-constexpr size_t RTU2_PV1_CURRENT = 4;               // length = 1
-constexpr size_t RTU2_PV1_ACTIVE_POWER = 5;          // length = 2
-constexpr size_t RTU2_PV2_VOLTAGE = 7;               // length = 1
-constexpr size_t RTU2_PV2_CURRENT = 8;               // length = 1
-constexpr size_t RTU2_PV2_ACTIVE_POWER = 9;          // length = 2
-constexpr size_t RTU2_GRID_ACTIVE_POWER = 35;        // length = 2
-constexpr size_t RTU2_GRID_FREQUENCY = 37;           // length = 1
-constexpr size_t RTU2_PHASE1_VOLTAGE = 38;           // length = 1
-constexpr size_t RTU2_PHASE1_CURRENT = 39;           // length = 1
-constexpr size_t RTU2_PHASE1_ACTIVE_POWER = 40;      // length = 2
-constexpr size_t RTU2_PHASE2_VOLTAGE = 42;           // length = 1
-constexpr size_t RTU2_PHASE2_CURRENT = 43;           // length = 1
-constexpr size_t RTU2_PHASE2_ACTIVE_POWER = 44;      // length = 2
-constexpr size_t RTU2_PHASE3_VOLTAGE = 46;           // length = 1
-constexpr size_t RTU2_PHASE3_CURRENT = 47;           // length = 1
-constexpr size_t RTU2_PHASE3_ACTIVE_POWER = 48;      // length = 2
-constexpr size_t RTU2_TODAY_PRODUCTION = 53;         // length = 2
-constexpr size_t RTU2_TOTAL_ENERGY_PRODUCTION = 55;  // length = 2
-constexpr size_t RTU2_INVERTER_MODULE_TEMP = 93;     // length = 1
+constexpr uint16_t RTU2_INVERTER_STATUS = 0;           // length = 1
+constexpr uint16_t RTU2_PV_ACTIVE_POWER = 1;           // length = 2
+constexpr uint16_t RTU2_PV1_VOLTAGE = 3;               // length = 1
+constexpr uint16_t RTU2_PV1_CURRENT = 4;               // length = 1
+constexpr uint16_t RTU2_PV1_ACTIVE_POWER = 5;          // length = 2
+constexpr uint16_t RTU2_PV2_VOLTAGE = 7;               // length = 1
+constexpr uint16_t RTU2_PV2_CURRENT = 8;               // length = 1
+constexpr uint16_t RTU2_PV2_ACTIVE_POWER = 9;          // length = 2
+constexpr uint16_t RTU2_GRID_ACTIVE_POWER = 35;        // length = 2
+constexpr uint16_t RTU2_GRID_FREQUENCY = 37;           // length = 1
+constexpr uint16_t RTU2_PHASE1_VOLTAGE = 38;           // length = 1
+constexpr uint16_t RTU2_PHASE1_CURRENT = 39;           // length = 1
+constexpr uint16_t RTU2_PHASE1_ACTIVE_POWER = 40;      // length = 2
+constexpr uint16_t RTU2_PHASE2_VOLTAGE = 42;           // length = 1
+constexpr uint16_t RTU2_PHASE2_CURRENT = 43;           // length = 1
+constexpr uint16_t RTU2_PHASE2_ACTIVE_POWER = 44;      // length = 2
+constexpr uint16_t RTU2_PHASE3_VOLTAGE = 46;           // length = 1
+constexpr uint16_t RTU2_PHASE3_CURRENT = 47;           // length = 1
+constexpr uint16_t RTU2_PHASE3_ACTIVE_POWER = 48;      // length = 2
+constexpr uint16_t RTU2_TODAY_PRODUCTION = 53;         // length = 2
+constexpr uint16_t RTU2_TOTAL_ENERGY_PRODUCTION = 55;  // length = 2
+constexpr uint16_t RTU2_INVERTER_MODULE_TEMP = 93;     // length = 1
 
 class GrowattSolar final : public PollingComponent, public modbus::ModbusClientDevice {
  public:
-  void loop() override;
   void update() override;
-  void on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) override;
+  void on_read_input_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                               modbus::ResponseStatus status) override;
   void dump_config() override;
 
   void set_protocol_version(GrowattProtocolVersion protocol_version) { this->protocol_version_ = protocol_version; }
@@ -104,9 +104,6 @@ class GrowattSolar final : public PollingComponent, public modbus::ModbusClientD
   }
 
  protected:
-  bool waiting_to_update_{false};
-  uint32_t last_send_{0};
-
   struct GrowattPhase {
     sensor::Sensor *voltage_sensor_{nullptr};
     sensor::Sensor *current_sensor_{nullptr};

esphome/components/havells_solar/havells_solar.cpp

@@ -1,124 +1,71 @@
 #include "havells_solar.h"
 #include "havells_solar_registers.h"
-#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 namespace esphome::havells_solar {
 
+namespace helpers = modbus::helpers;
+
 static const char *const TAG = "havells_solar";
 
 static const uint8_t MODBUS_REGISTER_COUNT = 48;  // 48 x 16-bit registers
 
-void HavellsSolar::on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) {
-  auto data = modbus::helpers::server_pdu_payload(response_pdu);
-  if (data.size() < MODBUS_REGISTER_COUNT * 2) {
-    ESP_LOGW(TAG, "Invalid size for HavellsSolar!");
-    return;
-  }
+void HavellsSolar::on_read_holding_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                                             modbus::ResponseStatus status) {
+  if (!modbus::succeeded(status))
+    return;  // the hub already logs exception responses
 
-  /* Usage: returns the float value of 1 register read by modbus
-            Arg1: Register address * number of bytes per register
-            Arg2: Multiplier for final register value
-  */
-  auto havells_solar_get_2_registers = [&](size_t i, float unit) -> float {
-    uint32_t temp = encode_uint32(data[i], data[i + 1], data[i + 2], data[i + 3]);
-    return temp * unit;
+  // Publish a sensor if its register(s) are in this response; skipping absent registers keeps this
+  // correct for any read range, so the poll may be split into multiple requests.
+  auto publish_1_register = [&](sensor::Sensor *sensor, uint16_t reg, float unit) -> void {
+    if (sensor == nullptr)
+      return;
+    if (auto value = helpers::value_at<helpers::SensorValueType::U_WORD>(registers, start_address, reg))
+      sensor->publish_state(*value * unit);
   };
 
-  /* Usage: returns the float value of 2 registers read by modbus
-            Arg1: Register address * number of bytes per register
-            Arg2: Multiplier for final register value
-  */
-  auto havells_solar_get_1_register = [&](size_t i, float unit) -> float {
-    uint16_t temp = encode_uint16(data[i], data[i + 1]);
-    return temp * unit;
+  auto publish_2_registers = [&](sensor::Sensor *sensor, uint16_t reg, float unit) -> void {
+    if (sensor == nullptr)
+      return;
+    if (auto value = helpers::value_at<helpers::SensorValueType::U_DWORD>(registers, start_address, reg))
+      sensor->publish_state(*value * unit);
   };
 
   for (uint8_t i = 0; i < 3; i++) {
-    auto phase = this->phases_[i];
+    auto &phase = this->phases_[i];
     if (!phase.setup)
       continue;
-
-    float voltage = havells_solar_get_1_register(HAVELLS_PHASE_1_VOLTAGE * 2 + (i * 4), ONE_DEC_UNIT);
-    float current = havells_solar_get_1_register(HAVELLS_PHASE_1_CURRENT * 2 + (i * 4), TWO_DEC_UNIT);
-
-    if (phase.voltage_sensor_ != nullptr)
-      phase.voltage_sensor_->publish_state(voltage);
-    if (phase.current_sensor_ != nullptr)
-      phase.current_sensor_->publish_state(current);
+    publish_1_register(phase.voltage_sensor_, HAVELLS_PHASE_1_VOLTAGE + i * 2, ONE_DEC_UNIT);
+    publish_1_register(phase.current_sensor_, HAVELLS_PHASE_1_CURRENT + i * 2, TWO_DEC_UNIT);
   }
 
   for (uint8_t i = 0; i < 2; i++) {
-    auto pv = this->pvs_[i];
+    auto &pv = this->pvs_[i];
     if (!pv.setup)
       continue;
-
-    float voltage = havells_solar_get_1_register(HAVELLS_PV_1_VOLTAGE * 2 + (i * 4), ONE_DEC_UNIT);
-    float current = havells_solar_get_1_register(HAVELLS_PV_1_CURRENT * 2 + (i * 4), TWO_DEC_UNIT);
-    float active_power = havells_solar_get_1_register(HAVELLS_PV_1_POWER * 2 + (i * 2), MULTIPLY_TEN_UNIT);
-    float voltage_sampled_by_secondary_cpu =
-        havells_solar_get_1_register(HAVELLS_PV1_VOLTAGE_SAMPLED_BY_SECONDARY_CPU * 2 + (i * 2), ONE_DEC_UNIT);
-    float insulation_of_p_to_ground =
-        havells_solar_get_1_register(HAVELLS_PV1_INSULATION_OF_P_TO_GROUND * 2 + (i * 2), NO_DEC_UNIT);
-
-    if (pv.voltage_sensor_ != nullptr)
-      pv.voltage_sensor_->publish_state(voltage);
-    if (pv.current_sensor_ != nullptr)
-      pv.current_sensor_->publish_state(current);
-    if (pv.active_power_sensor_ != nullptr)
-      pv.active_power_sensor_->publish_state(active_power);
-    if (pv.voltage_sampled_by_secondary_cpu_sensor_ != nullptr)
-      pv.voltage_sampled_by_secondary_cpu_sensor_->publish_state(voltage_sampled_by_secondary_cpu);
-    if (pv.insulation_of_p_to_ground_sensor_ != nullptr)
-      pv.insulation_of_p_to_ground_sensor_->publish_state(insulation_of_p_to_ground);
+    publish_1_register(pv.voltage_sensor_, HAVELLS_PV_1_VOLTAGE + i * 2, ONE_DEC_UNIT);
+    publish_1_register(pv.current_sensor_, HAVELLS_PV_1_CURRENT + i * 2, TWO_DEC_UNIT);
+    publish_1_register(pv.active_power_sensor_, HAVELLS_PV_1_POWER + i, MULTIPLY_TEN_UNIT);
+    publish_1_register(pv.voltage_sampled_by_secondary_cpu_sensor_, HAVELLS_PV1_VOLTAGE_SAMPLED_BY_SECONDARY_CPU + i,
+                       ONE_DEC_UNIT);
+    publish_1_register(pv.insulation_of_p_to_ground_sensor_, HAVELLS_PV1_INSULATION_OF_P_TO_GROUND + i, NO_DEC_UNIT);
   }
 
-  float frequency = havells_solar_get_1_register(HAVELLS_GRID_FREQUENCY * 2, TWO_DEC_UNIT);
-  float active_power = havells_solar_get_1_register(HAVELLS_SYSTEM_ACTIVE_POWER * 2, MULTIPLY_TEN_UNIT);
-  float reactive_power = havells_solar_get_1_register(HAVELLS_SYSTEM_REACTIVE_POWER * 2, TWO_DEC_UNIT);
-  float today_production = havells_solar_get_1_register(HAVELLS_TODAY_PRODUCTION * 2, TWO_DEC_UNIT);
-  float total_energy_production = havells_solar_get_2_registers(HAVELLS_TOTAL_ENERGY_PRODUCTION * 2, NO_DEC_UNIT);
-  float total_generation_time = havells_solar_get_2_registers(HAVELLS_TOTAL_GENERATION_TIME * 2, NO_DEC_UNIT);
-  float today_generation_time = havells_solar_get_1_register(HAVELLS_TODAY_GENERATION_TIME * 2, NO_DEC_UNIT);
-  float inverter_module_temp = havells_solar_get_1_register(HAVELLS_INVERTER_MODULE_TEMP * 2, NO_DEC_UNIT);
-  float inverter_inner_temp = havells_solar_get_1_register(HAVELLS_INVERTER_INNER_TEMP * 2, NO_DEC_UNIT);
-  float inverter_bus_voltage = havells_solar_get_1_register(HAVELLS_INVERTER_BUS_VOLTAGE * 2, NO_DEC_UNIT);
-  float insulation_pv_n_to_ground = havells_solar_get_1_register(HAVELLS_INSULATION_OF_PV_N_TO_GROUND * 2, NO_DEC_UNIT);
-  float gfci_value = havells_solar_get_1_register(HAVELLS_GFCI_VALUE * 2, NO_DEC_UNIT);
-  float dci_of_r = havells_solar_get_1_register(HAVELLS_DCI_OF_R * 2, NO_DEC_UNIT);
-  float dci_of_s = havells_solar_get_1_register(HAVELLS_DCI_OF_S * 2, NO_DEC_UNIT);
-  float dci_of_t = havells_solar_get_1_register(HAVELLS_DCI_OF_T * 2, NO_DEC_UNIT);
-
-  if (this->frequency_sensor_ != nullptr)
-    this->frequency_sensor_->publish_state(frequency);
-  if (this->active_power_sensor_ != nullptr)
-    this->active_power_sensor_->publish_state(active_power);
-  if (this->reactive_power_sensor_ != nullptr)
-    this->reactive_power_sensor_->publish_state(reactive_power);
-  if (this->today_production_sensor_ != nullptr)
-    this->today_production_sensor_->publish_state(today_production);
-  if (this->total_energy_production_sensor_ != nullptr)
-    this->total_energy_production_sensor_->publish_state(total_energy_production);
-  if (this->total_generation_time_sensor_ != nullptr)
-    this->total_generation_time_sensor_->publish_state(total_generation_time);
-  if (this->today_generation_time_sensor_ != nullptr)
-    this->today_generation_time_sensor_->publish_state(today_generation_time);
-  if (this->inverter_module_temp_sensor_ != nullptr)
-    this->inverter_module_temp_sensor_->publish_state(inverter_module_temp);
-  if (this->inverter_inner_temp_sensor_ != nullptr)
-    this->inverter_inner_temp_sensor_->publish_state(inverter_inner_temp);
-  if (this->inverter_bus_voltage_sensor_ != nullptr)
-    this->inverter_bus_voltage_sensor_->publish_state(inverter_bus_voltage);
-  if (this->insulation_pv_n_to_ground_sensor_ != nullptr)
-    this->insulation_pv_n_to_ground_sensor_->publish_state(insulation_pv_n_to_ground);
-  if (this->gfci_value_sensor_ != nullptr)
-    this->gfci_value_sensor_->publish_state(gfci_value);
-  if (this->dci_of_r_sensor_ != nullptr)
-    this->dci_of_r_sensor_->publish_state(dci_of_r);
-  if (this->dci_of_s_sensor_ != nullptr)
-    this->dci_of_s_sensor_->publish_state(dci_of_s);
-  if (this->dci_of_t_sensor_ != nullptr)
-    this->dci_of_t_sensor_->publish_state(dci_of_t);
+  publish_1_register(this->frequency_sensor_, HAVELLS_GRID_FREQUENCY, TWO_DEC_UNIT);
+  publish_1_register(this->active_power_sensor_, HAVELLS_SYSTEM_ACTIVE_POWER, MULTIPLY_TEN_UNIT);
+  publish_1_register(this->reactive_power_sensor_, HAVELLS_SYSTEM_REACTIVE_POWER, TWO_DEC_UNIT);
+  publish_1_register(this->today_production_sensor_, HAVELLS_TODAY_PRODUCTION, TWO_DEC_UNIT);
+  publish_2_registers(this->total_energy_production_sensor_, HAVELLS_TOTAL_ENERGY_PRODUCTION, NO_DEC_UNIT);
+  publish_2_registers(this->total_generation_time_sensor_, HAVELLS_TOTAL_GENERATION_TIME, NO_DEC_UNIT);
+  publish_1_register(this->today_generation_time_sensor_, HAVELLS_TODAY_GENERATION_TIME, NO_DEC_UNIT);
+  publish_1_register(this->inverter_module_temp_sensor_, HAVELLS_INVERTER_MODULE_TEMP, NO_DEC_UNIT);
+  publish_1_register(this->inverter_inner_temp_sensor_, HAVELLS_INVERTER_INNER_TEMP, NO_DEC_UNIT);
+  publish_1_register(this->inverter_bus_voltage_sensor_, HAVELLS_INVERTER_BUS_VOLTAGE, NO_DEC_UNIT);
+  publish_1_register(this->insulation_pv_n_to_ground_sensor_, HAVELLS_INSULATION_OF_PV_N_TO_GROUND, NO_DEC_UNIT);
+  publish_1_register(this->gfci_value_sensor_, HAVELLS_GFCI_VALUE, NO_DEC_UNIT);
+  publish_1_register(this->dci_of_r_sensor_, HAVELLS_DCI_OF_R, NO_DEC_UNIT);
+  publish_1_register(this->dci_of_s_sensor_, HAVELLS_DCI_OF_S, NO_DEC_UNIT);
+  publish_1_register(this->dci_of_t_sensor_, HAVELLS_DCI_OF_T, NO_DEC_UNIT);
 }
 
 void HavellsSolar::update() { this->read_holding_registers(0, MODBUS_REGISTER_COUNT); }

esphome/components/havells_solar/havells_solar.h

@@ -77,7 +77,8 @@ class HavellsSolar final : public PollingComponent, public modbus::ModbusClientD
 
   void update() override;
 
-  void on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) override;
+  void on_read_holding_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                                 modbus::ResponseStatus status) override;
 
   void dump_config() override;
 

esphome/components/internal_temperature/sensor.py

@@ -1,5 +1,7 @@
 import esphome.codegen as cg
 from esphome.components import sensor
+from esphome.components.esp32 import get_esp32_variant, include_builtin_idf_component
+from esphome.components.esp32.const import VARIANT_ESP32
 from esphome.components.zephyr import zephyr_add_prj_conf
 from esphome.config_helpers import filter_source_files_from_platform
 import esphome.config_validation as cv
@@ -48,6 +50,10 @@ async def to_code(config: ConfigType) -> None:
     var = await sensor.new_sensor(config)
     await cg.register_component(var, config)
 
+    if CORE.is_esp32 and get_esp32_variant() == VARIANT_ESP32:
+        # temprature_sens_read() lives in the esp_phy blob, which is excluded by default
+        include_builtin_idf_component("esp_phy")
+
     if CORE.using_zephyr and CORE.is_nrf52:
         zephyr_add_prj_conf("SENSOR", True)
         zephyr_add_prj_conf("TEMP_NRF5", True)

esphome/components/kuntze/kuntze.cpp

@@ -1,87 +1,74 @@
 #include "kuntze.h"
-#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
-#include "esphome/core/application.h"
 
 namespace esphome::kuntze {
 
 static const char *const TAG = "kuntze";
 
-static const uint16_t REGISTER[] = {4136, 4160, 4680, 6000, 4688, 4728, 5832};
+static constexpr uint16_t REGISTER_PH = 4136;
+static constexpr uint16_t REGISTER_TEMPERATURE = 4160;
+static constexpr uint16_t REGISTER_DIS1 = 4680;
+static constexpr uint16_t REGISTER_DIS2 = 6000;
+static constexpr uint16_t REGISTER_REDOX = 4688;
+static constexpr uint16_t REGISTER_EC = 4728;
+static constexpr uint16_t REGISTER_OCI = 5832;
+static constexpr uint16_t REGISTER[] = {REGISTER_PH,    REGISTER_TEMPERATURE, REGISTER_DIS1, REGISTER_DIS2,
+                                        REGISTER_REDOX, REGISTER_EC,          REGISTER_OCI};
 
-// Maximum bytes to log for Modbus responses (2 registers = 4, plus count = 5)
-static constexpr size_t KUNTZE_MAX_LOG_BYTES = 8;
+void Kuntze::on_read_holding_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                                       modbus::ResponseStatus status) {
+  if (!modbus::succeeded(status) || registers.size() < 2)
+    return;
 
-void Kuntze::on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) {
-  auto data = modbus::helpers::server_pdu_payload(response_pdu);
-  auto get_16bit = [&](int i) -> uint16_t { return (uint16_t(data[i * 2]) << 8) | uint16_t(data[i * 2 + 1]); };
+  // Each value is a register pair: the reading, then the number of decimal places in its low byte.
+  float value = registers[0];
+  for (uint16_t i = 0; i < (registers[1] & 0xFF); i++)
+    value /= 10.0f;
 
-  this->waiting_ = false;
-#if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE
-  char hex_buf[format_hex_pretty_size(KUNTZE_MAX_LOG_BYTES)];
-#endif
-  ESP_LOGV(TAG, "Data: %s", format_hex_pretty_to(hex_buf, data.data(), data.size()));
-
-  float value = (float) get_16bit(0);
-  for (int i = 0; i < data[3]; i++)
-    value /= 10.0;
-  switch (this->state_) {
-    case 1:
+  switch (start_address) {
+    case REGISTER_PH:
       ESP_LOGD(TAG, "pH=%.1f", value);
       if (this->ph_sensor_ != nullptr)
         this->ph_sensor_->publish_state(value);
       break;
-    case 2:
+    case REGISTER_TEMPERATURE:
       ESP_LOGD(TAG, "temperature=%.1f", value);
       if (this->temperature_sensor_ != nullptr)
         this->temperature_sensor_->publish_state(value);
       break;
-    case 3:
+    case REGISTER_DIS1:
       ESP_LOGD(TAG, "DIS1=%.1f", value);
       if (this->dis1_sensor_ != nullptr)
         this->dis1_sensor_->publish_state(value);
       break;
-    case 4:
+    case REGISTER_DIS2:
       ESP_LOGD(TAG, "DIS2=%.1f", value);
       if (this->dis2_sensor_ != nullptr)
         this->dis2_sensor_->publish_state(value);
       break;
-    case 5:
+    case REGISTER_REDOX:
       ESP_LOGD(TAG, "REDOX=%.1f", value);
       if (this->redox_sensor_ != nullptr)
         this->redox_sensor_->publish_state(value);
       break;
-    case 6:
+    case REGISTER_EC:
       ESP_LOGD(TAG, "EC=%.1f", value);
       if (this->ec_sensor_ != nullptr)
         this->ec_sensor_->publish_state(value);
       break;
-    case 7:
+    case REGISTER_OCI:
       ESP_LOGD(TAG, "OCI=%.1f", value);
       if (this->oci_sensor_ != nullptr)
         this->oci_sensor_->publish_state(value);
       break;
   }
-  if (++this->state_ > 7)
-    this->state_ = 0;
 }
 
-void Kuntze::loop() {
-  uint32_t now = App.get_loop_component_start_time();
-  // timeout after 15 seconds
-  if (this->waiting_ && (now - this->last_send_ > 15000)) {
-    ESP_LOGW(TAG, "timed out waiting for response");
-    this->waiting_ = false;
-  }
-  if (this->waiting_ || (this->state_ == 0))
-    return;
-  this->last_send_ = now;
-  this->read_holding_registers(REGISTER[this->state_ - 1], 2);
-  this->waiting_ = true;
+void Kuntze::update() {
+  for (uint16_t reg : REGISTER)
+    this->read_holding_registers(reg, 2);
 }
 
-void Kuntze::update() { this->state_ = 1; }
-
 void Kuntze::dump_config() {
   ESP_LOGCONFIG(TAG,
                 "Kuntze:\n"

esphome/components/kuntze/kuntze.h

@@ -18,18 +18,14 @@ class Kuntze final : public PollingComponent, public modbus::ModbusClientDevice
   void set_ec_sensor(sensor::Sensor *ec_sensor) { ec_sensor_ = ec_sensor; }
   void set_oci_sensor(sensor::Sensor *oci_sensor) { oci_sensor_ = oci_sensor; }
 
-  void loop() override;
   void update() override;
 
-  void on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) override;
+  void on_read_holding_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                                 modbus::ResponseStatus status) override;
 
   void dump_config() override;
 
  protected:
-  int state_{0};
-  bool waiting_{false};
-  uint32_t last_send_{0};
-
   sensor::Sensor *ph_sensor_{nullptr};
   sensor::Sensor *temperature_sensor_{nullptr};
   sensor::Sensor *dis1_sensor_{nullptr};

esphome/components/light/esp_color_correction.cpp

@@ -5,7 +5,11 @@ namespace esphome::light {
 uint8_t ESPColorCorrection::gamma_correct_(uint8_t value) const {
   if (this->gamma_table_ == nullptr)
     return value;
-  return static_cast<uint8_t>((progmem_read_uint16(&this->gamma_table_[value]) + 128) / 257);
+  uint16_t table_value = progmem_read_uint16(&this->gamma_table_[value]);
+  uint8_t result = (table_value + 128) / 257;
+  if (result == 0 && table_value != 0)
+    return 1;
+  return result;
 }
 
 uint8_t ESPColorCorrection::gamma_uncorrect_(uint8_t value) const {

esphome/components/lvgl/defines.py

@@ -483,6 +483,7 @@ LV_ANIM = LvConstant(
 
 LV_GRAD_DIR = LvConstant("LV_GRAD_DIR_", "NONE", "HOR", "VER")
 LV_DITHER = LvConstant("LV_DITHER_", "NONE", "ORDERED", "ERR_DIFF")
+LV_GRAD_EXTEND = LvConstant("LV_GRAD_EXTEND_", "PAD", "REPEAT", "REFLECT")
 
 LV_LOG_LEVELS = {
     "VERBOSE": "TRACE",
@@ -904,7 +905,7 @@ LV_COLOR_FORMATS = (
 
 LV_DEFINES = (
     "LV_USE_FREERTOS_TASK_NOTIFY", "LV_DRAW_BUF_STRIDE_ALIGN", "LV_USE_DRAW_SW", "LV_DRAW_SW_DRAW_UNIT_CNT",
-    "LV_DRAW_SW_COMPLEX", "LV_USE_DRAW_PXP", "LV_USE_PXP_DRAW_THREAD", "LV_USE_DRAW_G2D",
+    "LV_DRAW_SW_COMPLEX", "LV_USE_DRAW_SW_COMPLEX_GRADIENTS", "LV_USE_DRAW_PXP", "LV_USE_PXP_DRAW_THREAD", "LV_USE_DRAW_G2D",
     "LV_USE_G2D_DRAW_THREAD", "LV_VG_LITE_USE_BOX_SHADOW", "LV_VG_LITE_THORVG_16PIXELS_ALIGN", "LV_LOG_USE_TIMESTAMP",
     "LV_LOG_USE_FILE_LINE", "LV_USE_OBJ_ID_BUILTIN", "LV_USE_OBJ_PROPERTY_NAME", "LV_ATTRIBUTE_MEM_ALIGN_SIZE",
     "LV_FONT_MONTSERRAT_14", "LV_USE_FONT_PLACEHOLDER", "LV_WIDGETS_HAS_DEFAULT_VALUE", "LV_USE_ARCLABEL",

esphome/components/lvgl/gradient.py

@@ -13,18 +13,40 @@ from esphome.core import ID
 from esphome.cpp_generator import MockObj
 
 from .defines import (
+    CONF_END_ANGLE,
     CONF_GRADIENTS,
     CONF_OPA,
+    CONF_START_ANGLE,
     LV_DITHER,
+    LV_GRAD_EXTEND,
     add_define,
     add_lv_use,
     add_warning,
 )
-from .lv_validation import lv_color, lv_percentage, opacity
+from .lv_validation import (
+    lv_angle_degrees,
+    lv_color,
+    lv_percentage,
+    opacity,
+    pixels_or_percent,
+)
 from .lvcode import lv
 from .types import lv_color_t, lv_gradient_t, lv_opa_t
 
 CONF_STOPS = "stops"
+CONF_LINEAR = "linear"
+CONF_RADIAL = "radial"
+CONF_CONICAL = "conical"
+CONF_EXTEND = "extend"
+CONF_FROM_X = "from_x"
+CONF_FROM_Y = "from_y"
+CONF_TO_X = "to_x"
+CONF_TO_Y = "to_y"
+CONF_CENTER_X = "center_x"
+CONF_CENTER_Y = "center_y"
+CONF_FOCAL_X = "focal_x"
+CONF_FOCAL_Y = "focal_y"
+CONF_FOCAL_RADIUS = "focal_radius"
 
 
 def min_stops(value):
@@ -33,27 +55,109 @@ def min_stops(value):
     return value
 
 
+STOPS_SCHEMA = cv.All(
+    [
+        cv.Schema(
+            {
+                cv.Required(CONF_COLOR): lv_color,
+                cv.Optional(CONF_OPA, default=1.0): opacity,
+                cv.Required(CONF_POSITION): lv_percentage,
+            }
+        )
+    ],
+    min_stops,
+)
+
+LINEAR_SCHEMA = cv.Schema(
+    {
+        cv.Required(CONF_FROM_X): pixels_or_percent,
+        cv.Required(CONF_FROM_Y): pixels_or_percent,
+        cv.Required(CONF_TO_X): pixels_or_percent,
+        cv.Required(CONF_TO_Y): pixels_or_percent,
+        cv.Optional(CONF_EXTEND, default="PAD"): LV_GRAD_EXTEND.one_of,
+    }
+)
+
+RADIAL_SCHEMA = cv.Schema(
+    {
+        cv.Required(CONF_CENTER_X): pixels_or_percent,
+        cv.Required(CONF_CENTER_Y): pixels_or_percent,
+        cv.Required(CONF_TO_X): pixels_or_percent,
+        cv.Required(CONF_TO_Y): pixels_or_percent,
+        cv.Optional(CONF_FOCAL_X): pixels_or_percent,
+        cv.Optional(CONF_FOCAL_Y): pixels_or_percent,
+        # No default: gradient_validator() must be able to tell whether this was actually
+        # given, to require it alongside focal_x/focal_y rather than silently drop it.
+        # LVGL's lv_grad_radial_set_focal() takes this as a scalar, not lv_pct() -
+        # unlike every other coordinate here, a percentage is not accepted.
+        cv.Optional(CONF_FOCAL_RADIUS): cv.positive_int,
+        cv.Optional(CONF_EXTEND, default="PAD"): LV_GRAD_EXTEND.one_of,
+    }
+)
+
+CONICAL_SCHEMA = cv.Schema(
+    {
+        cv.Required(CONF_CENTER_X): pixels_or_percent,
+        cv.Required(CONF_CENTER_Y): pixels_or_percent,
+        cv.Optional(CONF_START_ANGLE, default=0): lv_angle_degrees,
+        cv.Optional(CONF_END_ANGLE, default=360): lv_angle_degrees,
+        cv.Optional(CONF_EXTEND, default="PAD"): LV_GRAD_EXTEND.one_of,
+    }
+)
+
+
+def gradient_validator(config):
+    direction = config[CONF_DIRECTION]
+    for gradient_direction, key in (
+        ("LINEAR", CONF_LINEAR),
+        ("RADIAL", CONF_RADIAL),
+        ("CONICAL", CONF_CONICAL),
+    ):
+        if direction == gradient_direction:
+            if key not in config:
+                raise cv.Invalid(
+                    f"'{key}' is required for {gradient_direction} gradient direction"
+                )
+        elif key in config:
+            raise cv.Invalid(
+                f"'{key}' is only valid with 'direction: {gradient_direction}'"
+            )
+    if CONF_RADIAL in config:
+        radial = config[CONF_RADIAL]
+        has_focal_x = CONF_FOCAL_X in radial
+        has_focal_y = CONF_FOCAL_Y in radial
+        has_focal_radius = CONF_FOCAL_RADIUS in radial
+        if has_focal_x != has_focal_y or (has_focal_radius and not has_focal_x):
+            raise cv.Invalid(
+                "'focal_x', 'focal_y' and 'focal_radius' must be specified together "
+                "in 'radial'"
+            )
+    return config
+
+
 GRADIENT_SCHEMA = cv.ensure_list(
-    cv.Schema(
-        {
-            cv.GenerateID(CONF_ID): cv.declare_id(lv_gradient_t),
-            cv.Required(CONF_DIRECTION): cv.one_of(
-                "HOR", "HORIZONTAL", "VER", "VERTICAL", upper=True
-            ),
-            cv.Optional(CONF_DITHER): LV_DITHER.one_of,
-            cv.Required(CONF_STOPS): cv.All(
-                [
-                    cv.Schema(
-                        {
-                            cv.Required(CONF_COLOR): lv_color,
-                            cv.Optional(CONF_OPA, default=1.0): opacity,
-                            cv.Required(CONF_POSITION): lv_percentage,
-                        }
-                    )
-                ],
-                min_stops,
-            ),
-        }
+    cv.All(
+        cv.Schema(
+            {
+                cv.GenerateID(CONF_ID): cv.declare_id(lv_gradient_t),
+                cv.Required(CONF_DIRECTION): cv.one_of(
+                    "HOR",
+                    "HORIZONTAL",
+                    "VER",
+                    "VERTICAL",
+                    "LINEAR",
+                    "RADIAL",
+                    "CONICAL",
+                    upper=True,
+                ),
+                cv.Optional(CONF_DITHER): LV_DITHER.one_of,
+                cv.Optional(CONF_LINEAR): LINEAR_SCHEMA,
+                cv.Optional(CONF_RADIAL): RADIAL_SCHEMA,
+                cv.Optional(CONF_CONICAL): CONICAL_SCHEMA,
+                cv.Required(CONF_STOPS): STOPS_SCHEMA,
+            }
+        ),
+        gradient_validator,
     )
 )
 
@@ -65,15 +169,60 @@ async def gradients_to_code(config):
         add_warning(
             "The 'dither' option for gradients is not supported by LVGL 9.x and will be ignored"
         )
+    if any(
+        x[CONF_DIRECTION] in ("LINEAR", "RADIAL", "CONICAL")
+        for x in config.get(CONF_GRADIENTS, ())
+    ):
+        # LVGL's software renderer only draws these gradient types when this is enabled; without
+        # it they silently fall back to a plain horizontal gradient.
+        add_define("LV_USE_DRAW_SW_COMPLEX_GRADIENTS")
     for gradient in config.get(CONF_GRADIENTS, ()):
         var = MockObj(cg.new_Pvariable(gradient[CONF_ID]), "->")
         idbase = gradient[CONF_ID].id
         stops = sorted(gradient[CONF_STOPS], key=itemgetter(CONF_POSITION))
         max_stops = max(max_stops, len(stops))
-        if gradient[CONF_DIRECTION].startswith("VER"):
+        direction = gradient[CONF_DIRECTION]
+        if direction.startswith("VER"):
             lv.grad_vertical_init(var)
-        else:
+        elif direction.startswith("HOR"):
             lv.grad_horizontal_init(var)
+        elif direction == "LINEAR":
+            linear = gradient[CONF_LINEAR]
+            lv.grad_linear_init(
+                var,
+                await pixels_or_percent.process(linear[CONF_FROM_X]),
+                await pixels_or_percent.process(linear[CONF_FROM_Y]),
+                await pixels_or_percent.process(linear[CONF_TO_X]),
+                await pixels_or_percent.process(linear[CONF_TO_Y]),
+                await LV_GRAD_EXTEND.process(linear[CONF_EXTEND]),
+            )
+        elif direction == "RADIAL":
+            radial = gradient[CONF_RADIAL]
+            lv.grad_radial_init(
+                var,
+                await pixels_or_percent.process(radial[CONF_CENTER_X]),
+                await pixels_or_percent.process(radial[CONF_CENTER_Y]),
+                await pixels_or_percent.process(radial[CONF_TO_X]),
+                await pixels_or_percent.process(radial[CONF_TO_Y]),
+                await LV_GRAD_EXTEND.process(radial[CONF_EXTEND]),
+            )
+            if CONF_FOCAL_X in radial:
+                lv.grad_radial_set_focal(
+                    var,
+                    await pixels_or_percent.process(radial[CONF_FOCAL_X]),
+                    await pixels_or_percent.process(radial[CONF_FOCAL_Y]),
+                    radial.get(CONF_FOCAL_RADIUS, 0),
+                )
+        elif direction == "CONICAL":
+            conical = gradient[CONF_CONICAL]
+            lv.grad_conical_init(
+                var,
+                await pixels_or_percent.process(conical[CONF_CENTER_X]),
+                await pixels_or_percent.process(conical[CONF_CENTER_Y]),
+                await lv_angle_degrees.process(conical[CONF_START_ANGLE]),
+                await lv_angle_degrees.process(conical[CONF_END_ANGLE]),
+                await LV_GRAD_EXTEND.process(conical[CONF_EXTEND]),
+            )
         stop_colors = cg.static_const_array(
             ID(idbase + "_colors_", type=lv_color_t),
             [await lv_color.process(x[CONF_COLOR]) for x in stops],

esphome/components/mdns/__init__.py

@@ -1,5 +1,5 @@
 import esphome.codegen as cg
-from esphome.components.esp32 import add_idf_component
+from esphome.components.esp32 import add_idf_component, add_idf_sdkconfig_option
 from esphome.config_helpers import filter_source_files_from_platform, get_logger_level
 import esphome.config_validation as cv
 from esphome.const import (
@@ -9,6 +9,7 @@ from esphome.const import (
     CONF_PROTOCOL,
     CONF_SERVICE,
     CONF_SERVICES,
+    CONF_WIFI,
     PlatformFramework,
 )
 from esphome.core import CORE, Lambda, coroutine_with_priority
@@ -208,7 +209,16 @@ async def to_code(config: ConfigType) -> None:
                 ethernet.request_ethernet_ip_state_listener()
 
     if CORE.is_esp32:
-        add_idf_component(name="espressif/mdns", ref="1.11.3")
+        add_idf_component(name="espressif/mdns", ref="1.12.0")
+        # ESPHome only advertises; the browse APIs are unused
+        add_idf_sdkconfig_option("CONFIG_MDNS_ENABLE_BROWSE", False)
+        # The mdns console CLI is never used by ESPHome
+        add_idf_sdkconfig_option("CONFIG_MDNS_ENABLE_CONSOLE_CLI", False)
+        if CONF_WIFI not in CORE.config:
+            # Without WiFi the predefined STA/AP interface handlers are dead
+            # code; disabling them lets mdns build without the WiFi stack.
+            add_idf_sdkconfig_option("CONFIG_MDNS_PREDEF_NETIF_STA", False)
+            add_idf_sdkconfig_option("CONFIG_MDNS_PREDEF_NETIF_AP", False)
 
     cg.add_define("USE_MDNS")
 

esphome/components/mipi_rgb/models/elecrow.py

@@ -0,0 +1,28 @@
+from . import RgbDriverChip
+
+# fmt: off
+RgbDriverChip(
+    "CROWPANEL-ADVANCE-7",
+    requires={"psram"},
+    initsequence=(),
+    pclk_frequency="20MHz",
+    hsync_pulse_width=4,
+    hsync_front_porch=8,
+    hsync_back_porch=8,
+    vsync_pulse_width=4,
+    vsync_front_porch=8,
+    vsync_back_porch=8,
+    pclk_inverted=True,
+    color_order="RGB",
+    width=800,
+    height=480,
+    de_pin=42,
+    hsync_pin=40,
+    vsync_pin=41,
+    pclk_pin=39,
+    data_pins={
+        "red": [7, 17, 18, 3, 46],
+        "green": [9, 10, 11, 12, 13, 14],
+        "blue": [21, 47, 48, 45, 38],
+    },
+)

esphome/components/mk2pvrouter/__init__.py

@@ -0,0 +1,69 @@
+import esphome.codegen as cg
+from esphome.components import uart
+import esphome.config_validation as cv
+from esphome.const import CONF_ID, CONF_TAG
+from esphome.cpp_generator import MockObj
+from esphome.types import ConfigType
+
+CODEOWNERS = ["@FredM67"]
+DEPENDENCIES = ["uart"]
+
+mk2pvrouter_ns = cg.esphome_ns.namespace("mk2pvrouter")
+Mk2PVRouter = mk2pvrouter_ns.class_("Mk2PVRouter", cg.Component, uart.UARTDevice)
+
+CONF_MK2PVROUTER_ID = "mk2pvrouter_id"
+
+# Tags are copied into a fixed-size buffer (MAX_TAG_SIZE = 8 in mk2pvrouter.h),
+# which needs room for a trailing null terminator.
+MAX_TAG_LEN = 7
+
+MK2PVROUTER_LISTENER_SCHEMA = cv.Schema(
+    {
+        cv.GenerateID(CONF_MK2PVROUTER_ID): cv.use_id(Mk2PVRouter),
+        cv.Required(CONF_TAG): cv.All(
+            cv.string_strict, cv.Length(min=1, max=MAX_TAG_LEN), lambda x: x.upper()
+        ),
+    }
+)
+
+CONFIG_SCHEMA = (
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.declare_id(Mk2PVRouter),
+        }
+    )
+    .extend(cv.COMPONENT_SCHEMA)
+    .extend(uart.UART_DEVICE_SCHEMA)
+)
+
+
+def final_validate(config: ConfigType) -> None:
+    # Validate UART settings
+    schema = uart.final_validate_device_schema(
+        "mk2pvrouter",
+        baud_rate=9600,
+        parity="EVEN",
+        data_bits=7,
+        stop_bits=1,
+        require_rx=True,
+        require_tx=False,
+    )
+    schema(config)
+
+
+FINAL_VALIDATE_SCHEMA = final_validate
+
+
+_request_listener_slot = cg.slot_counter("MK2PVROUTER_LISTENER_COUNT")
+
+
+async def register_mk2pvrouter_listener(mk2pvrouter: MockObj, var: MockObj) -> None:
+    """Register a listener with its hub and count it for the compile-time buffer size."""
+    _request_listener_slot()
+    cg.add(mk2pvrouter.register_mk2pvrouter_listener(var))
+
+
+async def to_code(config: ConfigType) -> None:
+    var = cg.new_Pvariable(config[CONF_ID])
+    await cg.register_component(var, config)
+    await uart.register_uart_device(var, config)

esphome/components/mk2pvrouter/mk2pvrouter.cpp

@@ -0,0 +1,177 @@
+#include "mk2pvrouter.h"
+#include "esphome/core/log.h"
+#include <cstring>
+
+namespace esphome::mk2pvrouter {
+
+static const char *const TAG = "mk2pvrouter";
+
+constexpr uint8_t START_FRAME = 0x2;
+constexpr uint8_t END_FRAME = 0x3;
+constexpr uint8_t LINE_FEED = 0xa;
+constexpr uint8_t CARRIAGE_RETURN = 0xd;
+constexpr uint8_t TAB = 0x9;
+constexpr uint8_t MAX_ITERATIONS = 128;
+constexpr uint8_t CRC_MASK = 0x3F;
+constexpr uint8_t CRC_OFFSET = 0x20;
+
+// Extracts a TAB-delimited field from [buf_start, buf_end) into dest.
+// Returns the field length, or 0 if no TAB was found, or the (uncopied) field
+// length if it's >= max_len.
+static size_t get_field(char *dest, const char *buf_start, const char *buf_end, size_t max_len) {
+  const auto *const field_end = static_cast<const char *>(memchr(buf_start, TAB, buf_end - buf_start));
+  if (!field_end)
+    return 0;
+  const size_t len = field_end - buf_start;
+  if (len >= max_len) {
+    ESP_LOGE(TAG, "Field too long: %zu bytes (max %zu)", len, max_len);
+    return len;
+  }
+
+  memcpy(dest, buf_start, len);
+  dest[len] = '\0';  // Null-terminate
+  return len;
+}
+
+// Calculates the CRC (checksum) for a given group of characters.
+uint8_t Mk2PVRouter::calculate_crc_(const char *grp, size_t grp_len) {
+  uint8_t crc_tmp{0};
+  const auto effective_len = grp_len - CRC_SUFFIX_LEN;
+  for (size_t i = 0; i < effective_len; i++) {
+    crc_tmp += grp[i];
+  }
+  crc_tmp &= CRC_MASK;
+  crc_tmp += CRC_OFFSET;
+  return crc_tmp;
+}
+
+// Verifies the CRC of a group against its trailing CRC byte.
+bool Mk2PVRouter::check_crc_(const char *grp, const char *grp_end) {
+  const auto grp_len = grp_end - grp;
+  if (grp_len < static_cast<decltype(grp_len)>(CRC_SUFFIX_LEN)) {
+    ESP_LOGE(TAG, "Empty or too short group");
+    return false;
+  }
+  const auto raw_crc = grp[grp_len - 1];
+
+  const auto calculated_crc = this->calculate_crc_(grp, grp_len);
+
+  if (raw_crc != calculated_crc) {
+    ESP_LOGE(TAG, "CRC mismatch: expected %d, got %d", calculated_crc, raw_crc);
+    return false;
+  }
+  return true;
+}
+
+// Validates, parses, and publishes a single tag/value group.
+void Mk2PVRouter::process_group_(const char *grp, const char *grp_end) {
+  if (!this->check_crc_(grp, grp_end))
+    return;
+
+  size_t field_len = get_field(this->tag_, grp, grp_end, MAX_TAG_SIZE);
+  if (!field_len || field_len >= MAX_TAG_SIZE) {
+    ESP_LOGE(TAG, "Invalid tag");
+    return;
+  }
+  const auto *val_start = grp + field_len + 1;  // Skip tag + TAB.
+
+  field_len = get_field(this->val_, val_start, grp_end, MAX_VAL_SIZE);
+  if (!field_len || field_len >= MAX_VAL_SIZE) {
+    ESP_LOGE(TAG, "Invalid value for tag %s", this->tag_);
+    return;
+  }
+
+  this->publish_value_(this->tag_, this->val_);
+}
+
+// Reads characters until `c` is found or the internal buffer is full.
+bool Mk2PVRouter::read_chars_until_(bool drop, uint8_t c) {
+  size_t j{0};
+
+  while (this->available() > 0 && j++ < MAX_ITERATIONS) {
+    const auto received = this->read();
+    if (received < 0)
+      continue;
+    if (received == c)
+      return true;
+    if (drop)
+      continue;
+    if (this->buf_index_ >= (sizeof(this->buf_) - 1)) {
+      ESP_LOGW(TAG, "Internal buffer full");
+      this->buf_index_ = 0;
+      this->state_ = State::WAITING_FOR_START;
+      return false;
+    }
+    this->buf_[this->buf_index_++] = received;
+  }
+
+  return false;
+}
+
+void Mk2PVRouter::loop() {
+  switch (this->state_) {
+    case State::WAITING_FOR_START:
+      ESP_LOGVV(TAG, "State: WAITING_FOR_START");
+      if (this->read_chars_until_(true, START_FRAME))
+        this->state_ = State::START_FRAME_RECEIVED;
+      break;
+    case State::START_FRAME_RECEIVED:
+      ESP_LOGVV(TAG, "State: START_FRAME_RECEIVED");
+      if (this->read_chars_until_(false, END_FRAME))
+        this->state_ = State::END_FRAME_RECEIVED;
+      break;
+    case State::END_FRAME_RECEIVED: {
+      ESP_LOGVV(TAG, "State: END_FRAME_RECEIVED -> processing");
+
+      if (this->buf_index_ == 0) {
+        this->state_ = State::WAITING_FOR_START;
+        break;
+      }
+
+      auto *buf_finger = this->buf_;
+      auto *buf_end = this->buf_ + this->buf_index_;
+
+      // Each group: 0xa(LF) | Tag | 0x9(TAB) | Data | 0x9(TAB) | CRC | 0xd(CR)
+      // CRC is computed over "Tag | TAB | Data | TAB".
+      while ((buf_finger = static_cast<char *>(memchr(buf_finger, LINE_FEED, buf_end - buf_finger))) != nullptr) {
+        ++buf_finger;  // Skip LF to the start of the group.
+
+        auto *const grp_end = static_cast<char *>(memchr(buf_finger, CARRIAGE_RETURN, buf_end - buf_finger));
+        if (!grp_end) {
+          ESP_LOGE(TAG, "No group found");
+          break;
+        }
+
+        this->process_group_(buf_finger, grp_end);
+
+        buf_finger = grp_end;  // grp_end is always < buf_end, so this stays in bounds.
+      }
+      this->buf_index_ = 0;
+      this->state_ = State::WAITING_FOR_START;
+      break;
+    }
+  }
+}
+
+void Mk2PVRouter::publish_value_(const char *tag, const char *val) {
+#ifdef MK2PVROUTER_LISTENER_COUNT
+  for (auto *element : this->mk2pvrouter_listeners_) {
+    if (strcmp(tag, element->get_tag()) != 0)
+      continue;
+    element->publish_val(val);
+  }
+#endif
+}
+
+void Mk2PVRouter::dump_config() {
+  ESP_LOGCONFIG(TAG, "Mk2PVRouter:");
+  this->check_uart_settings(BAUD_RATE, 1, uart::UART_CONFIG_PARITY_EVEN, 7);
+}
+
+#ifdef MK2PVROUTER_LISTENER_COUNT
+void Mk2PVRouter::register_mk2pvrouter_listener(Mk2PVRouterListener *listener) {
+  this->mk2pvrouter_listeners_.push_back(listener);
+}
+#endif
+
+}  // namespace esphome::mk2pvrouter

esphome/components/mk2pvrouter/mk2pvrouter.h

@@ -0,0 +1,69 @@
+#pragma once
+
+#include "esphome/components/uart/uart.h"
+#include "esphome/core/component.h"
+#include "esphome/core/defines.h"
+#include "esphome/core/helpers.h"
+
+namespace esphome::mk2pvrouter {
+/*
+ * Buffer sizes based on the mk2pvrouter telemetry protocol, as implemented by the
+ * firmware's teleinfo.h (see github.com/FredM67/PVRouter-{1,3}-phase):
+ * - Tags: max 4 chars (S_MC is longest), most are 1-2 chars (P, V1, R2, etc.)
+ * - Values: max 6 digits signed (-10000), typical 1-5 digits. Energy (E) is a daily
+ *   counter reset at midnight, so it stays well within 6 digits.
+ * - Frame: STX + multiple lines (LF+tag+TAB+value+TAB+crc+CR) + ETX
+ * - Line format: \n<tag>\t<value>\t<crc>\r (8-15 bytes per line)
+ * - Multi-phase with all features: ~150-200 bytes
+ */
+static constexpr uint8_t MAX_TAG_SIZE = 8;     // S_MC (4) + digit (1) + null (1) + margin (2)
+static constexpr uint8_t MAX_VAL_SIZE = 8;     // -10000 (6) + null (1) + margin (1)
+static constexpr uint16_t MAX_BUF_SIZE = 256;  // Full frame with all features enabled
+
+// Listener interface for entities that want updates for a specific tag.
+class Mk2PVRouterListener {
+ public:
+  explicit Mk2PVRouterListener(const char *tag) : tag_(tag) {}
+  virtual ~Mk2PVRouterListener() = default;
+  const char *get_tag() const { return this->tag_; }
+  virtual void publish_val(const char *val) = 0;
+
+ protected:
+  const char *tag_;
+};
+
+// Reads frames via UART, validates their CRC, and publishes tag/value pairs to listeners.
+class Mk2PVRouter final : public Component, public uart::UARTDevice {
+ public:
+#ifdef MK2PVROUTER_LISTENER_COUNT
+  void register_mk2pvrouter_listener(Mk2PVRouterListener *listener);
+#endif
+  void loop() override;
+  void dump_config() override;
+
+ protected:
+  static constexpr size_t CRC_SUFFIX_LEN = 1;
+  static constexpr uint32_t BAUD_RATE = 9600;
+
+  enum class State : uint8_t {
+    WAITING_FOR_START,
+    START_FRAME_RECEIVED,
+    END_FRAME_RECEIVED,
+  };
+
+#ifdef MK2PVROUTER_LISTENER_COUNT
+  StaticVector<Mk2PVRouterListener *, MK2PVROUTER_LISTENER_COUNT> mk2pvrouter_listeners_;
+#endif
+  uint16_t buf_index_{0};
+  State state_{State::WAITING_FOR_START};
+  char tag_[MAX_TAG_SIZE];
+  char val_[MAX_VAL_SIZE];
+  char buf_[MAX_BUF_SIZE];  // Large buffer last to reduce padding
+
+  bool read_chars_until_(bool drop, uint8_t c);
+  uint8_t calculate_crc_(const char *grp, size_t grp_len);
+  bool check_crc_(const char *grp, const char *grp_end);
+  void process_group_(const char *grp, const char *grp_end);
+  void publish_value_(const char *tag, const char *val);
+};
+}  // namespace esphome::mk2pvrouter

esphome/components/mk2pvrouter/sensor/__init__.py

@@ -0,0 +1,27 @@
+import esphome.codegen as cg
+from esphome.components import sensor
+from esphome.const import CONF_ID, CONF_TAG
+from esphome.types import ConfigType
+
+from .. import (
+    CONF_MK2PVROUTER_ID,
+    MK2PVROUTER_LISTENER_SCHEMA,
+    mk2pvrouter_ns,
+    register_mk2pvrouter_listener,
+)
+
+Mk2PVRouterSensor = mk2pvrouter_ns.class_(
+    "Mk2PVRouterSensor", sensor.Sensor, cg.Component
+)
+
+CONFIG_SCHEMA = sensor.sensor_schema(Mk2PVRouterSensor).extend(
+    MK2PVROUTER_LISTENER_SCHEMA
+)
+
+
+async def to_code(config: ConfigType) -> None:
+    var = cg.new_Pvariable(config[CONF_ID], config[CONF_TAG])
+    await cg.register_component(var, config)
+    await sensor.register_sensor(var, config)
+    mk2pvrouter = await cg.get_variable(config[CONF_MK2PVROUTER_ID])
+    await register_mk2pvrouter_listener(mk2pvrouter, var)

esphome/components/mk2pvrouter/sensor/mk2pvrouter_sensor.cpp

@@ -0,0 +1,24 @@
+#include "mk2pvrouter_sensor.h"
+#include "esphome/core/log.h"
+
+namespace esphome::mk2pvrouter {
+
+static const char *const TAG = "mk2pvrouter_sensor";
+
+Mk2PVRouterSensor::Mk2PVRouterSensor(const char *tag) : Mk2PVRouterListener(tag) {}
+
+void Mk2PVRouterSensor::publish_val(const char *val) {
+  auto result = parse_number<float>(val);
+  if (!result.has_value()) {
+    ESP_LOGW(TAG, "Failed to parse value '%s' for tag '%s'", val, this->get_tag());
+    return;
+  }
+  this->publish_state(result.value());
+}
+
+void Mk2PVRouterSensor::dump_config() {
+  LOG_SENSOR("  ", "Mk2PVRouter Sensor", this);
+  ESP_LOGCONFIG(TAG, "  Tag: %s", this->get_tag());
+}
+
+}  // namespace esphome::mk2pvrouter

esphome/components/mk2pvrouter/sensor/mk2pvrouter_sensor.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include "esphome/components/mk2pvrouter/mk2pvrouter.h"
+#include "esphome/components/sensor/sensor.h"
+
+namespace esphome::mk2pvrouter {
+
+class Mk2PVRouterSensor final : public Mk2PVRouterListener, public sensor::Sensor, public Component {
+ public:
+  explicit Mk2PVRouterSensor(const char *tag);
+  void publish_val(const char *val) override;
+  void dump_config() override;
+};
+
+}  // namespace esphome::mk2pvrouter

esphome/components/modbus/__init__.py

@@ -89,9 +89,8 @@ _WRITE_FUNCTION_CODES = frozenset({0x05, 0x06, 0x0F, 0x10, 0x16, 0x17})
 
 def is_function_code_write(function_code: int) -> bool:
     """True if the Modbus function code writes (mutates). The exception bit (0x80) is masked off first,
-    so an exception-flagged code still classifies by its base code - stricter than the runtime hub,
-    whose classify() treats an exception-flagged code as a read. Keep in sync with
-    modbus::helpers::is_function_code_write()."""
+    so an exception-flagged code still classifies by its base code (the runtime hub never queues one:
+    queue_pdu() refuses them). Keep in sync with modbus::helpers::is_function_code_write()."""
     return function_code & 0x7F in _WRITE_FUNCTION_CODES
 
 

esphome/components/modbus/modbus.cpp

@@ -3,6 +3,7 @@
 #include <algorithm>
 
 #include "esphome/core/application.h"
+#include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
@@ -10,43 +11,55 @@ namespace esphome::modbus {
 
 static const char *const TAG = "modbus";
 
-// Maximum bytes to log for Modbus frames (truncated if larger)
 static constexpr size_t MODBUS_MAX_LOG_BYTES = 64;
 
-// Approximate bits per character on the wire (depends on parity/stop bit config)
-static constexpr uint32_t MODBUS_BITS_PER_CHAR = 11;
-// Milliseconds per second
-static constexpr uint32_t MS_PER_SEC = 1000;
+static constexpr uint32_t US_PER_SEC = 1000000;
+static constexpr uint32_t US_PER_MS = 1000;
 
-// Shortest gap between two "no device accepted broadcast" warnings
-static constexpr uint32_t UNACCEPTED_BROADCAST_WARN_INTERVAL_MS = 60 * MS_PER_SEC;
+// Minimum interframe delay per the Modbus spec (fixed 1750us above 19200 baud)
+static constexpr uint32_t MODBUS_MIN_FRAME_DELAY_US = 1750;
+
+// Diagnostics only: the backdated byte stamp can precede last_send_ (echo, or noise during our own
+// send), where an unsigned wrap would print ~4.29e9.
+static uint32_t us_since_send(uint32_t last_modbus_byte, uint32_t last_send) {
+  const uint32_t elapsed = last_modbus_byte - last_send;
+  return (int32_t) elapsed < 0 ? 0 : elapsed;
+}
 
 void Modbus::setup() {
   if (this->flow_control_pin_ != nullptr) {
     this->flow_control_pin_->setup();
   }
 
-  this->frame_delay_ms_ =
-      std::max(2,  // 1750us minimum per spec - rounded up to 2ms.
-                   // 3.5 characters * 11 bits per character * 1000ms/sec / (bits/sec) (Standard modbus frame delay)
-               (uint16_t) (3.5 * MODBUS_BITS_PER_CHAR * MS_PER_SEC / this->parent_->get_baud_rate()) + 1);
+  // RTU specifies 11 bits per character but 8N1 is 10, so derive it from the framing. The schema
+  // forbids a zero, so one here means the hub never set it (weikai): fall back to 8N1 and a 1 baud floor.
+  const uint8_t data_bits = this->parent_->get_data_bits() != 0 ? this->parent_->get_data_bits() : 8;
+  const uint8_t stop_bits = this->parent_->get_stop_bits() != 0 ? this->parent_->get_stop_bits() : 1;
+  const uint32_t baud_rate = std::max<uint32_t>(1u, this->parent_->get_baud_rate());
+  this->bits_per_char_ = static_cast<uint8_t>(
+      1 + data_bits + (this->parent_->get_parity() == uart::UART_CONFIG_PARITY_NONE ? 0 : 1) + stop_bits);
+
+  // 3.5 characters * bits per character * 1e6 us/sec / (bits/sec) (Standard modbus frame delay)
+  this->frame_delay_us_ =
+      std::max(MODBUS_MIN_FRAME_DELAY_US, (uint32_t) (3.5 * this->bits_per_char_ * US_PER_SEC / baud_rate) + 1);
 
   // When rx_full_threshold is configured (non-zero), the UART has a hardware FIFO with a
   // meaningful threshold (e.g., ESP32 native UART), so we can calculate a precise delay.
   // Otherwise (e.g., USB UART), use 50ms to handle data arriving in chunks.
-  static constexpr uint16_t DEFAULT_LONG_RX_BUFFER_DELAY_MS = 50;
+  static constexpr uint32_t DEFAULT_LONG_RX_BUFFER_DELAY_US = 50 * US_PER_MS;
   size_t rx_threshold = this->parent_->get_rx_full_threshold();
-  this->long_rx_buffer_delay_ms_ =
-      rx_threshold != uart::UARTComponent::RX_FULL_THRESHOLD_UNSET
-          ? (rx_threshold * MODBUS_BITS_PER_CHAR * MS_PER_SEC / this->parent_->get_baud_rate()) + 1
-          : DEFAULT_LONG_RX_BUFFER_DELAY_MS;
+  this->long_rx_buffer_delay_us_ = rx_threshold != uart::UARTComponent::RX_FULL_THRESHOLD_UNSET
+                                       ? (uint32_t) (rx_threshold * this->bits_per_char_ * US_PER_SEC / baud_rate) + 1
+                                       : DEFAULT_LONG_RX_BUFFER_DELAY_US;
+
+  // The idle-timeout interrupt fires rx_timeout characters after the last byte, so that much silence
+  // has already passed by the time we read it: backdate so the gap measures silence on the wire.
+  this->rx_detect_latency_us_ =
+      (uint32_t) (this->parent_->get_rx_timeout() * this->bits_per_char_ * US_PER_SEC / baud_rate);
 }
 
 void Modbus::loop() {
-  // Receive any available bytes from UART
   this->receive_bytes_();
-
-  // Parse bytes into frames and process them
   this->parse_modbus_frames();
 }
 
@@ -55,12 +68,12 @@ void ModbusClientHub::loop() {
   // never times out an entry whose pending count has not been drained. No-op when nothing is owed.
   this->sweep_();
 
-  this->Modbus::loop();  // receive bytes and parse frames
+  this->Modbus::loop();
 
   // Send-wait watchdog: only the cheap time check runs at loop rate; expire_waiting_() looks the
   // entry up and holds off if the response has started arriving.
   if (this->waiting_for_response_ &&
-      this->last_receive_check_ - this->last_send_ > this->last_send_tx_offset_ + this->send_wait_time_) {
+      this->last_receive_check_ - this->last_send_ > this->last_send_tx_offset_ + this->send_wait_time_us_) {
     this->expire_waiting_();
   }
 
@@ -80,7 +93,7 @@ void ModbusClientHub::expire_waiting_() {
   }
   // Only a genuine WAITING entry warrants the log (a cleared or interrupted shell timing out is expected).
   if (cmd->state == FrameState::WAITING) {
-    ESP_LOGW(TAG, "Stop waiting for response from %" PRIu8 " %" PRIu32 "ms after last send", cmd->frame.address(),
+    ESP_LOGW(TAG, "Stop waiting for response from %" PRIu8 " %" PRIu32 "us after last send", cmd->frame.address(),
              this->last_receive_check_ - this->last_send_);
   }
   // Deliver on_no_response directly, the way the parse path delivers response()/error(): the entry
@@ -94,52 +107,50 @@ void ModbusClientHub::expire_waiting_() {
 bool Modbus::timeout_() {
   // If the response frame is finished (including interframe delay) - we timeout.
   // The long_rx_buffer_delay accounts for long responses (larger than the UART rx_full_threshold) to avoid timeouts
-  // when the buffer is filling the back half of the response
-  const uint16_t timeout = std::max(
-      (uint16_t) this->frame_delay_ms_,
-      (uint16_t) (this->rx_buffer_.size() >= this->parent_->get_rx_full_threshold() ? this->long_rx_buffer_delay_ms_
-                                                                                    : 0));
+  // when the buffer is filling the back half of the response. The latch decides, not the current size:
+  // parsing a leading frame can shrink the buffer below the threshold while the rest is still streaming.
+  // The latency term covers the final batch, which is idle-delivered.
+  const uint32_t timeout =
+      this->exceeded_rx_full_threshold_
+          ? std::max(this->frame_delay_us_, this->long_rx_buffer_delay_us_ + this->rx_detect_latency_us_)
+          : this->frame_delay_us_;
 
   return this->last_receive_check_ - this->last_modbus_byte_ > timeout;
 }
 
+// We use micros() here and elsewhere instead of App.get_loop_component_start_time() to avoid stale timestamps
+// It's critical in all timestamp comparisons that the left timestamp comes before the right one in time
+// If we use a cached value in place of micros() and last_modbus_byte_ is updated inside our loop
+// then the comparison is backwards (small negative which wraps to large positive) and will cause a false timeout
+// So in this component we don't use any cached timestamp values to avoid these annoying bugs.
+// Compare before subtracting: a signed difference would read a bus idle past half the micros() wrap
+// (~35 min) as a huge delay still owed.
+static inline uint32_t remaining_delay(uint32_t elapsed, uint32_t required) {
+  return elapsed >= required ? 0 : required - elapsed;
+}
+
 int32_t Modbus::tx_delay_remaining() {
-  // We use millis() here and elsewhere instead of App.get_loop_component_start_time() to avoid stale timestamps
-  // It's critical in all timestamp comparisons that the left timestamp comes before the right one in time
-  // If we use a cached value in place of millis() and last_modbus_byte_ is updated inside our loop
-  // then the comparison is backwards (small negative which wraps to large positive) and will cause a false timeout
-  // So in this component we don't use any cached timestamp values to avoid these annoying bugs
-  const uint32_t now = millis();
-  return std::max({(int32_t) 0,
-                   (int32_t) (this->last_send_tx_offset_ + this->frame_delay_ms_ - (now - this->last_send_)),
-                   (int32_t) (this->frame_delay_ms_ - (now - this->last_modbus_byte_))});
+  const uint32_t now = micros();
+  return (int32_t) std::max(remaining_delay(now - this->last_send_, this->last_send_tx_offset_ + this->frame_delay_us_),
+                            remaining_delay(now - this->last_modbus_byte_, this->frame_delay_us_));
 }
 
 int32_t ModbusClientHub::tx_delay_remaining() {
-  const uint32_t now = millis();
-  return std::max({(int32_t) 0,
-                   (int32_t) (this->last_send_tx_offset_ + this->frame_delay_ms_ + this->turnaround_delay_ms_ -
-                              (now - this->last_send_)),
-                   (int32_t) (this->frame_delay_ms_ + this->turnaround_delay_ms_ - (now - this->last_modbus_byte_))});
+  const uint32_t now = micros();
+  return (int32_t) std::max(
+      remaining_delay(now - this->last_send_,
+                      this->last_send_tx_offset_ + this->frame_delay_us_ + this->turnaround_delay_us_),
+      remaining_delay(now - this->last_modbus_byte_, this->frame_delay_us_ + this->turnaround_delay_us_));
 }
 
 bool Modbus::tx_blocked() {
-  // We block transmission in any of these cases:
-  // 1. There are bytes in the UART Rx buffer
-  // 2. There are bytes in our Rx buffer
-  // 3. The last sent byte isn't more than tx_delay ms ago (i.e. wait to tell receivers that our previous Tx is done)
-  // 4. The last received byte isn't more than tx_delay ms ago (i.e. wait to be sure there isn't more Rx coming)
-  // N.B. We allow a small delay (MODBUS_TX_MAX_DELAY_MS) to avoid looping on small delays. This gets handled by
-  // send_frame_.
-  return this->available() || !this->rx_buffer_.empty() || this->tx_delay_remaining() > MODBUS_TX_MAX_DELAY_MS;
+  // Blocked while any rx bytes are pending, or within tx_delay of the last byte in either direction
+  // (receivers must see our previous tx as done, and more rx may be coming). A remaining delay up to
+  // MODBUS_TX_MAX_DELAY_US doesn't block - send_frame_ absorbs it instead of looping on small waits.
+  return this->available() || !this->rx_buffer_.empty() || this->tx_delay_remaining() > MODBUS_TX_MAX_DELAY_US;
 }
 
-bool ModbusClientHub::tx_blocked() {
-  // We block transmission in any of these case:
-  // 1. We're waiting for a response (a waiting entry: WAITING/INTERRUPTED/WAITING_RETIRED/INTERRUPTED_RETIRED)
-  // 2. Any of the base class tx_blocked conditions
-  return this->waiting_for_response_ || this->Modbus::tx_blocked();
-}
+bool ModbusClientHub::tx_blocked() { return this->waiting_for_response_ || this->Modbus::tx_blocked(); }
 
 bool ModbusClientHub::tx_buffer_empty() {
   // "Empty" for ready_for_immediate_send(): no one-shot is queued ahead of the caller. Entries in
@@ -153,20 +164,26 @@ bool ModbusClientHub::tx_buffer_empty() {
 }
 
 void Modbus::receive_bytes_() {
-  this->last_receive_check_ = millis();
+  this->last_receive_check_ = micros();
   size_t bytes = this->available();
 
   if (bytes) {
     size_t buffer_size = this->rx_buffer_.size();
-    this->last_modbus_byte_ = this->last_receive_check_;
+    // Below the threshold the batch can only be idle-delivered, so its last byte finished one detection
+    // latency ago; at or above it the frame may still be streaming, so stamp now.
+    this->last_modbus_byte_ = bytes < this->parent_->get_rx_full_threshold()
+                                  ? this->last_receive_check_ - this->rx_detect_latency_us_
+                                  : this->last_receive_check_;
     this->rx_buffer_.resize(buffer_size + bytes);
     if (!this->read_array(this->rx_buffer_.data() + buffer_size, bytes)) {
       this->rx_buffer_.resize(buffer_size);
       return;
     }
+    if (this->rx_buffer_.size() >= this->parent_->get_rx_full_threshold())
+      this->exceeded_rx_full_threshold_ = true;
     if (buffer_size == 0) {
-      ESP_LOGV(TAG, "Received first byte %" PRIu8 " (0X%x) of %zu bytes %" PRIu32 "ms after last send",
-               this->rx_buffer_[0], this->rx_buffer_[0], this->rx_buffer_.size(), millis() - this->last_send_);
+      ESP_LOGV(TAG, "Received first byte %" PRIu8 " (0X%x) of %zu bytes %" PRIu32 "us after last send",
+               this->rx_buffer_[0], this->rx_buffer_[0], this->rx_buffer_.size(), micros() - this->last_send_);
     }
   }
 }
@@ -219,10 +236,9 @@ void ModbusServerHub::parse_modbus_frames() {
     this->clear_rx_buffer_(LOG_STR("timeout after partial response"), true);
 }
 
+// Scans forward from min_length to find a frame boundary by CRC match for unknown-length function codes.
+// Returns the matched frame length, or 0 if no valid CRC was found within MAX_FRAME_SIZE.
 uint16_t Modbus::find_frame_end_by_crc_(uint16_t min_length) const {
-  // Unknown-length functions (user-defined codes, unimplemented management codes, unassigned values)
-  // could be any length - we have to rely on the CRC to determine completeness.
-  // If a CRC match is never found, the buffer will eventually overflow and be cleared.
   const uint8_t *raw = &this->rx_buffer_[0];
   const size_t size = this->rx_buffer_.size();
   const auto max_len = static_cast<uint16_t>(std::min(size, size_t(MAX_FRAME_SIZE)));
@@ -320,8 +336,8 @@ void ModbusClientHub::process_modbus_server_frame(uint8_t address, std::span<con
   ModbusDeviceCommand *cmd = this->waiting_for_response_ ? this->find_waiting_() : nullptr;
   if (cmd == nullptr) {
     ESP_LOGW(TAG,
-             "Received unexpected frame from address %" PRIu8 ", function code 0x%X, %" PRIu32 "ms after last send",
-             address, function_code, this->last_modbus_byte_ - this->last_send_);
+             "Received unexpected frame from address %" PRIu8 ", function code 0x%X, %" PRIu32 "us after last send",
+             address, function_code, us_since_send(this->last_modbus_byte_, this->last_send_));
     return;
   }
 
@@ -331,9 +347,9 @@ void ModbusClientHub::process_modbus_server_frame(uint8_t address, std::span<con
   if (expected_address != address || expected_function_code != (function_code & FUNCTION_CODE_MASK)) {
     ESP_LOGW(TAG,
              "Received incorrect frame address %" PRIu8 " <> %" PRIu8 " or function code 0x%X <> 0x%X, %" PRIu32
-             "ms after last send",
+             "us after last send",
              address, expected_address, (function_code & FUNCTION_CODE_MASK), expected_function_code,
-             this->last_modbus_byte_ - this->last_send_);
+             us_since_send(this->last_modbus_byte_, this->last_send_));
     // Unexpected frame: flip a WAITING entry to an INTERRUPTED shell that ignores the rest of this
     // transaction and blocks tx until the send-wait timeout, where it gets its on_no_response.
     cmd->interrupt();
@@ -346,8 +362,8 @@ void ModbusClientHub::process_modbus_server_frame(uint8_t address, std::span<con
     // cleared-interrupted frame still ends in on_no_response rather than delivering a late response.
     ESP_LOGW(TAG,
              "Ignoring response from %" PRIu8 " - transmission interrupted by previous unexpected response, %" PRIu32
-             "ms after last send",
-             address, this->last_modbus_byte_ - this->last_send_);
+             "us after last send",
+             address, us_since_send(this->last_modbus_byte_, this->last_send_));
     return;
   }
 
@@ -358,12 +374,12 @@ void ModbusClientHub::process_modbus_server_frame(uint8_t address, std::span<con
   this->sweep_needed_ = true;
   if (helpers::is_function_code_exception(function_code)) {
     uint8_t exception = pdu[1];  // exception frames are fixed-length, so the code is always present
-    ESP_LOGW(TAG, "Error function code: 0x%X exception: %" PRIu8 ", address: %" PRIu8 ", %" PRIu32 "ms after last send",
-             function_code, exception, address, this->last_modbus_byte_ - this->last_send_);
+    ESP_LOGW(TAG, "Error function code: 0x%X exception: %" PRIu8 ", address: %" PRIu8 ", %" PRIu32 "us after last send",
+             function_code, exception, address, us_since_send(this->last_modbus_byte_, this->last_send_));
     cmd->error(static_cast<ExceptionCode>(exception));
   } else if (!cmd->response(pdu)) {
-    ESP_LOGV(TAG, "Ignoring response from %" PRIu8 " - no callback device set, %" PRIu32 "ms after last send", address,
-             this->last_modbus_byte_ - this->last_send_);
+    ESP_LOGV(TAG, "Ignoring response from %" PRIu8 " - no callback device set, %" PRIu32 "us after last send", address,
+             us_since_send(this->last_modbus_byte_, this->last_send_));
   }
 }
 
@@ -531,8 +547,7 @@ void ModbusServerHub::process_broadcast_frame_(uint8_t function_code, std::span<
     return;
   }
   // A broadcast is never answered, so a rejecting device has no other feedback channel: report the
-  // per-device outcome at V, and warn if the write reached nobody at all.
-  bool accepted = false;
+  // per-device outcome at V.
   for (auto *device : this->devices_) {
     // Same handlers as an addressed write - a device cannot tell a broadcast apart, and does not need
     // to: the hub owns the difference, which is only that no reply is ever sent.
@@ -542,24 +557,6 @@ void ModbusServerHub::process_broadcast_frame_(uint8_t function_code, std::span<
     if (device_status.has_value()) {
       ESP_LOGV(TAG, "Device %" PRIu8 " rejected broadcast write with exception %" PRIu8, device->get_address(),
                static_cast<uint8_t>(device_status.value()));
-    } else {
-      accepted = true;
-    }
-  }
-  if (!accepted && !this->devices_.empty()) {
-    const uint16_t entity_count = coils ? coil_count : static_cast<uint16_t>(registers.size());
-    const LogString *const entity_name = coils ? LOG_STR("coils") : LOG_STR("registers");
-    // Warn at most once per interval, then drop to VERBOSE: on a shared bus a broadcast aimed at other nodes
-    // repeats forever, so warning per frame would flood the log.
-    const uint32_t now = millis();
-    if (this->last_unaccepted_broadcast_warn_ == 0 ||
-        now - this->last_unaccepted_broadcast_warn_ > UNACCEPTED_BROADCAST_WARN_INTERVAL_MS) {
-      this->last_unaccepted_broadcast_warn_ = now;
-      ESP_LOGW(TAG, "No device accepted broadcast write of %" PRIu16 " %s at 0x%04X", entity_count,
-               LOG_STR_ARG(entity_name), start_address);
-    } else {
-      ESP_LOGV(TAG, "No device accepted broadcast write of %" PRIu16 " %s at 0x%04X", entity_count,
-               LOG_STR_ARG(entity_name), start_address);
     }
   }
 }
@@ -778,13 +775,18 @@ void ModbusServerHub::process_modbus_client_frame_(uint8_t address, uint8_t func
 // Callers gate on tx_blocked() first, but the pre-send delay below can span several ms, so re-check
 // after it and refuse (return false) if a byte arrived in that window rather than transmit over it.
 bool Modbus::send_frame_(const ModbusFrame &frame) {
-  const int32_t tx_delay_remaining = this->tx_delay_remaining();
+  int32_t tx_delay_remaining = this->tx_delay_remaining();
   if (tx_delay_remaining > 0) {
-    delay(tx_delay_remaining);
+    // Yield the whole-ms part: delay() never blocks past the request on FreeRTOS, and only slightly
+    // over elsewhere, which just lengthens the gap. The recompute below makes the remainder exact.
+    if (tx_delay_remaining >= (int32_t) US_PER_MS) {
+      delay(tx_delay_remaining / US_PER_MS);
+      tx_delay_remaining = this->tx_delay_remaining();
+    }
+    if (tx_delay_remaining > 0)
+      delayMicroseconds(tx_delay_remaining);
   }
 
-  // The delay above can span several ms; a byte arriving in that window blocks transmission after the
-  // caller's gate already passed. Don't collide with the incoming frame - leave the entry to retry.
   if (this->tx_blocked()) {
     return false;
   }
@@ -797,14 +799,15 @@ bool Modbus::send_frame_(const ModbusFrame &frame) {
     this->last_send_tx_offset_ = 0;
   } else {
     this->write_array(frame.data.data(), frame.size());
-    this->last_send_tx_offset_ = frame.size() * MODBUS_BITS_PER_CHAR * MS_PER_SEC / this->parent_->get_baud_rate() + 1;
+    this->last_send_tx_offset_ =
+        frame.size() * this->bits_per_char_ * US_PER_SEC / std::max<uint32_t>(1u, this->parent_->get_baud_rate()) + 1;
   }
 
-  uint32_t now = millis();
+  uint32_t now = micros();
 #if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE
   char hex_buf[format_hex_pretty_size(MODBUS_MAX_LOG_BYTES)];
 #endif
-  ESP_LOGV(TAG, "Write: %s %" PRIu32 "ms after last send, %" PRIu32 "ms after last receive",
+  ESP_LOGV(TAG, "Write: %s %" PRIu32 "us after last send, %" PRIu32 "us after last receive",
            format_hex_pretty_to(hex_buf, frame.data.data(), frame.size()), now - this->last_send_,
            now - this->last_modbus_byte_);
   this->last_send_ = now;
@@ -812,6 +815,9 @@ bool Modbus::send_frame_(const ModbusFrame &frame) {
 }
 
 void ModbusClientHub::send_next_frame_() {
+  if (this->tx_buffer_.empty())
+    return;
+
   if (this->tx_blocked())
     return;
 
@@ -831,7 +837,7 @@ void ModbusClientHub::send_next_frame_() {
     // reports the transmission, and the entry then retires with no terminal callback instead of
     // occupying the waiting slot until the send-wait timeout expires. The turnaround delay already
     // spaces the next frame; the following sweep erases the entry.
-    ESP_LOGV(TAG, "Broadcast to address 0 sent; no reply expected (fire-and-forget)");
+    ESP_LOGV(TAG, "Broadcast to address 0 sent; no reply expected");
     cmd->complete_broadcast();
     this->sweep_needed_ = true;
     return;
@@ -842,20 +848,25 @@ void ModbusClientHub::send_next_frame_() {
 void ModbusClientHub::dump_config() {
   ESP_LOGCONFIG(TAG,
                 "Modbus:\n"
-                "  Send Wait Time: %" PRIu16 " ms\n"
-                "  Turnaround Time: %" PRIu16 " ms\n"
-                "  Frame Delay: %" PRIu16 " ms\n"
-                "  Long Rx Buffer Delay: %" PRIu16 " ms",
-                this->send_wait_time_, this->turnaround_delay_ms_, this->frame_delay_ms_,
-                this->long_rx_buffer_delay_ms_);
+                "  Send Wait Time: %" PRIu32 " ms\n"
+                "  Turnaround Time: %" PRIu32 " ms\n"
+                "  Frame Delay: %" PRIu32 " us\n"
+                "  Long Rx Buffer Delay: %" PRIu32 " us\n"
+                "  Bits Per Character: %" PRIu8 "\n"
+                "  Rx Detect Latency: %" PRIu32 " us",
+                this->send_wait_time_us_ / US_PER_MS, this->turnaround_delay_us_ / US_PER_MS, this->frame_delay_us_,
+                this->long_rx_buffer_delay_us_, this->bits_per_char_, this->rx_detect_latency_us_);
   LOG_PIN("  Flow Control Pin: ", this->flow_control_pin_);
 }
 void ModbusServerHub::dump_config() {
   ESP_LOGCONFIG(TAG,
                 "Modbus:\n"
-                "  Frame Delay: %" PRIu16 " ms\n"
-                "  Long Rx Buffer Delay: %" PRIu16 " ms",
-                this->frame_delay_ms_, this->long_rx_buffer_delay_ms_);
+                "  Frame Delay: %" PRIu32 " us\n"
+                "  Long Rx Buffer Delay: %" PRIu32 " us\n"
+                "  Bits Per Character: %" PRIu8 "\n"
+                "  Rx Detect Latency: %" PRIu32 " us",
+                this->frame_delay_us_, this->long_rx_buffer_delay_us_, this->bits_per_char_,
+                this->rx_detect_latency_us_);
   LOG_PIN("  Flow Control Pin: ", this->flow_control_pin_);
 }
 
@@ -983,6 +994,8 @@ bool ModbusDeviceCommand::timed_out() {
   this->decrement_pending();            // resolve this request (WAITING-origin, so pending >= 1)
   if (this->device == nullptr)
     return false;  // resolved, no one to tell
+  // A cleared frame that timed out still honors a retry: the clear is address-scoped (any device may
+  // call it) while the retry is the owning device's call via on_no_response - the bus obeys the owner.
   if (this->device->on_no_response(this->frame.pdu()))
     this->increment_pending();  // granted retry = re-request (capped)
   return true;
@@ -1054,18 +1067,14 @@ bool ModbusClientHub::queue_pdu(uint8_t address, std::span<const uint8_t> pdu, M
     ESP_LOGE(TAG, "Frame too large, refused: %" PRIu8 ":%zu bytes", address, pdu.size());
     return false;
   }
-  // classify() drives both the broadcast guard and the continuous check below; compute it once.
-  const CommandPriority priority = ModbusDeviceCommand::classify(pdu[0]);
 
-  // A broadcast (address 0) is never answered (Modbus 4.1), so it is only meaningful for a command that
-  // changes state. Refuse a broadcast that expects a reply - anything but a write or a custom/vendor code -
-  // as it could never deliver a result, so the caller learns via the false return (and on_not_sent).
-  // 0x17 (read/write multiple) is a knowing inclusion: classify() treats it as a write, so its write half
-  // lands on every server and its unanswerable read half is simply discarded. An exception-flagged custom
-  // code (0x80 bit set) is refused: is_function_code_custom() masks that bit away, so exclude it explicitly
-  // here to match classify()'s exception-first handling of the write side.
-  if (address == BROADCAST_ADDRESS && priority != CommandPriority::WRITE &&
-      (!helpers::is_function_code_custom(pdu[0]) || helpers::is_function_code_exception(pdu[0]))) {
+  if (helpers::is_function_code_exception(pdu[0])) {
+    ESP_LOGW(TAG, "Exception PDU refused for address %" PRIu8 ": function code 0x%X has the exception bit set", address,
+             pdu[0]);
+    return false;
+  }
+
+  if (address == BROADCAST_ADDRESS && !helpers::is_function_code_broadcastable(pdu[0])) {
     ESP_LOGW(TAG, "Broadcast refused for function 0x%X: a broadcast (address 0) is never answered", pdu[0]);
     return false;
   }
@@ -1073,7 +1082,7 @@ bool ModbusClientHub::queue_pdu(uint8_t address, std::span<const uint8_t> pdu, M
   // Normalize the caller's options in place (the param is a by-value copy) so everything stored or
   // merged below carries effective options, never the raw request.
   // continuous is ignored for every mutating code (re-writing a value forever is never intended).
-  if (options.continuous && priority == CommandPriority::WRITE) {
+  if (options.continuous && helpers::is_function_code_write(pdu[0])) {
     ESP_LOGW(TAG, "continuous is ignored for a mutating function (0x%X, address %" PRIu8 ")", pdu[0], address);
     options.continuous = false;
   }
@@ -1089,9 +1098,7 @@ bool ModbusClientHub::queue_pdu(uint8_t address, std::span<const uint8_t> pdu, M
       continue;
     if (device == nullptr) {
       // A dropped read is routine (DEBUG); a dropped write/custom warns (unobservable without a device).
-      const bool requeueable =
-          !helpers::is_function_code_exception(pdu[0]) && helpers::is_function_code_read_only(pdu[0]);
-      if (requeueable) {
+      if (helpers::is_function_code_read_only(pdu[0])) {
         ESP_LOGD(TAG, "Anonymous duplicate of active frame for %" PRIu8 " (function 0x%X), dropped", address, pdu[0]);
       } else {
         ESP_LOGW(TAG,
@@ -1188,7 +1195,8 @@ void ModbusServerHub::send_raw_(const uint8_t *payload, uint16_t len) {
     // without a heap allocation. Only one server reply is ever waiting, so a single buffer suffices.
     std::memcpy(this->deferred_payload_.data(), payload, len);
     this->deferred_payload_len_ = len;
-    this->set_timeout("deferred_send", this->tx_delay_remaining(), [this]() {
+    // set_timeout() takes milliseconds; round the microsecond delay up so we never fire early.
+    this->set_timeout("deferred_send", (this->tx_delay_remaining() + US_PER_MS - 1) / US_PER_MS, [this]() {
       ModbusFrame frame(this->deferred_payload_[0], this->deferred_payload_.data() + 1,
                         this->deferred_payload_len_ - 1);
       if (!this->send_frame_(frame))
@@ -1208,11 +1216,11 @@ void Modbus::clear_rx_buffer_(const LogString *reason, bool warn, size_t bytes_t
     bytes = bytes_to_clear;
   if (bytes > 0) {
     if (warn) {
-      ESP_LOGW(TAG, "Clearing buffer of %zu bytes - %s %" PRIu32 "ms after last send", bytes, LOG_STR_ARG(reason),
-               millis() - this->last_send_);
+      ESP_LOGW(TAG, "Clearing buffer of %zu bytes - %s %" PRIu32 "us after last send", bytes, LOG_STR_ARG(reason),
+               micros() - this->last_send_);
     } else {
-      ESP_LOGV(TAG, "Clearing buffer of %zu bytes - %s %" PRIu32 "ms after last send", bytes, LOG_STR_ARG(reason),
-               millis() - this->last_send_);
+      ESP_LOGV(TAG, "Clearing buffer of %zu bytes - %s %" PRIu32 "us after last send", bytes, LOG_STR_ARG(reason),
+               micros() - this->last_send_);
     }
     if (bytes == this->rx_buffer_.size()) {
       this->rx_buffer_.clear();
@@ -1220,6 +1228,8 @@ void Modbus::clear_rx_buffer_(const LogString *reason, bool warn, size_t bytes_t
       this->rx_buffer_.erase(this->rx_buffer_.begin(), this->rx_buffer_.begin() + bytes);
     }
   }
+  if (this->rx_buffer_.empty())
+    this->exceeded_rx_full_threshold_ = false;
 }
 
 void ModbusClientDevice::dispatch_response_(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu,
@@ -1364,7 +1374,6 @@ void ModbusClientDevice::dispatch_response_(std::span<const uint8_t> request_pdu
   }
 }
 
-// Default on_custom_response handler to warn when responses unexpectedly trigger on_custom_response
 void ModbusClientDevice::on_custom_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu,
                                             ResponseStatus status) {
   // The dispatcher never calls this with an empty request, but this is a public virtual - stay safe.

esphome/components/modbus/modbus.h

@@ -16,26 +16,21 @@
 
 namespace esphome::modbus {
 
-// Tx queue backstop. Duplicate frames dedup into one entry, so reads can never approach this in a
-// sane config - it exists to stop a runaway generator of distinct frames (e.g. a loop writing a
-// changing value) from growing the heap unboundedly. The deque grows on demand; this reserves nothing.
-// Worst case the cap permits: 128 distinct max-size frames = ~32 kB of spilled frame data plus
-// ~3 kB of deque node storage (typical 8-byte frames stay inline; large PDUs spill to one
-// allocation each) - pathological configs only, but the numbers matter when tuning for ESP8266.
+// Tx queue backstop: duplicates dedup into one entry, so only a runaway generator of distinct frames
+// (e.g. a loop writing a changing value) could grow the heap unboundedly.
 static constexpr uint16_t MODBUS_TX_BUFFER_SIZE = 128;
-static constexpr uint16_t MODBUS_TX_MAX_DELAY_MS = 5;
+static constexpr uint16_t MODBUS_TX_MAX_DELAY_US = 5000;
 
 // Typical frames -- reads and single-register/coil writes -- are exactly 8 bytes
-// (address + 5-byte PDU + 2-byte CRC) and fit inline with no heap allocation.
+// (address + 5-byte PDU + 2-byte CRC).
 static constexpr uint16_t MODBUS_FRAME_INLINE_SIZE = 8;
 
 struct ModbusFrame {
-  // Frame held in a small-buffer-optimized buffer. Typical frames fit inline; only larger
-  // multi-register or custom frames spill to a single heap allocation. This keeps the common,
-  // high-frequency tx traffic off the heap entirely, avoiding per-frame alloc/free churn.
-  // The buffer tracks its own length, so no separate size field is needed.
-  SmallInlineBuffer<MODBUS_FRAME_INLINE_SIZE> data;  // Modbus RTU max is 256 bytes
+  // Small-buffer-optimized: typical frames fit inline, keeping high-frequency tx traffic off the
+  // heap; only large multi-register or custom frames spill to a single heap allocation.
+  SmallInlineBuffer<MODBUS_FRAME_INLINE_SIZE> data;
 
+  // A frame is [address][PDU...][CRC lo][CRC hi]. These are the only places that need to know that layout
   ModbusFrame(uint8_t address, const uint8_t *pdu, uint16_t pdu_len) {
     uint8_t *buf = this->data.init(pdu_len + 3);
     buf[0] = address;
@@ -46,12 +41,9 @@ struct ModbusFrame {
   }
 
   uint16_t size() const { return static_cast<uint16_t>(this->data.size()); }
-
-  // A frame is [address][PDU...][CRC lo][CRC hi]. These are the only places that need to know that layout
   uint8_t address() const { return this->data.data()[0]; }
-  /// The PDU: function code + data, without address or CRC. Only valid while the frame is alive.
-  /// Requires a complete frame (size() >= MIN_FRAME_SIZE, guaranteed by the constructors) - the
-  /// subtraction would wrap on anything shorter.
+  /// A PDU is [function code][data...] without address or CRC. Only valid while the frame is alive.
+  /// Requires a complete frame (size() >= MIN_FRAME_SIZE, guaranteed by the constructors)
   std::span<const uint8_t> pdu() const { return std::span<const uint8_t>(this->data.data() + 1, this->size() - 3u); }
 };
 
@@ -73,23 +65,23 @@ class Modbus : public uart::UARTDevice, public Component {
   virtual int32_t tx_delay_remaining();
   virtual void parse_modbus_frames() = 0;
   bool parse_modbus_server_frame_();
-  // pdu is the whole PDU (function code + payload, no address/CRC); pdu[0] is the (standard or custom) function code.
   virtual void process_modbus_server_frame(uint8_t address, std::span<const uint8_t> pdu) = 0;
   void clear_rx_buffer_(const LogString *reason, bool warn = false, size_t bytes_to_clear = 0);
-  // Transmit a frame. Callers gate on tx_blocked() first, but the pre-send delay can span several ms,
-  // so this re-checks after the delay and returns false without transmitting if a byte arrived in that
-  // window (the caller then leaves its entry to retry). Returns true once the frame has been transmitted.
   bool send_frame_(const ModbusFrame &frame);
-  // Scans forward from min_length to find a frame boundary by CRC match for custom function codes.
-  // Returns the matched frame length, or 0 if no valid CRC was found within MAX_FRAME_SIZE.
   uint16_t find_frame_end_by_crc_(uint16_t min_length) const;
 
+  // All timestamps and durations below are micros()-based
   uint32_t last_modbus_byte_{0};
   uint32_t last_receive_check_{0};
   uint32_t last_send_{0};
   uint32_t last_send_tx_offset_{0};
-  uint16_t frame_delay_ms_{5};
-  uint16_t long_rx_buffer_delay_ms_{0};
+  uint32_t frame_delay_us_{5000};
+  uint32_t long_rx_buffer_delay_us_{0};
+  uint32_t rx_detect_latency_us_{0};
+  // Bits on the wire per character (start + data + optional parity + stop); 12 at most.
+  uint8_t bits_per_char_{11};
+  // Latched when a read reaches rx_full_threshold, cleared when the buffer drains.
+  bool exceeded_rx_full_threshold_{false};
 
   GPIOPin *flow_control_pin_{nullptr};
 
@@ -99,8 +91,7 @@ class Modbus : public uart::UARTDevice, public Component {
 class ModbusClientDevice;
 class ModbusServerDevice;
 
-// Transmit ordering, highest first: writes before one-shot reads before continuous polls. Derived
-// at selection time, never caller-chosen or stored.
+// Transmit ordering, highest first: writes before one-shot reads before continuous polls.
 enum class CommandPriority : uint8_t { CONTINUOUS = 0, READ, WRITE };
 
 // Per-entry lifecycle state. Waiting states (see waiting_state()) hold the bus; the sweep delivers owed
@@ -112,20 +103,15 @@ enum class FrameState : uint8_t {
   RECEIVED_EXCEPTION,
   TIMED_OUT,            // on_no_response delivered at the send-wait timeout; awaiting reschedule/erase
   INTERRUPTED,          // unexpected frame arrived; ignores this transaction, waits out the timeout
-  WAITING_RETIRED,      // cleared while WAITING: a late response is still delivered as its usual terminal
-  INTERRUPTED_RETIRED,  // cleared while INTERRUPTED: still distrusts late frames, ends in on_no_response
-  RETIRED,              // cleared, off the wire
+  WAITING_RETIRED,      // retired while WAITING: a late response is still delivered as its usual terminal
+  INTERRUPTED_RETIRED,  // retired while INTERRUPTED: still distrusts late frames, ends in on_no_response
+  RETIRED,              // retired, off the wire
 };
 
 // Per-command send options. Append-only; pass via designated initializers ({.continuous = true}).
-// The queue entry stores this struct whole, so a new field arrives at the queue with no plumbing -
-// but it arrives inert. Every new field must define three rules before it does anything:
-//   1. normalization in queue_pdu() (is it valid for this function code? e.g. continuous is
-//      stripped for mutating codes),
-//   2. a merge rule for when a duplicate send absorbs into a live entry (continuous
-//      upgrades/downgrades via make_continuous(); a new field needs its own answer),
-//   3. teardown: retire() resets the whole struct; silent_retire() leaves it, relying on the sweep
-//      to erase the entry.
+// A new field reaches the queue with no plumbing but arrives inert until it defines three rules:
+// normalization in queue_pdu(), a merge rule for duplicate absorption, and teardown in
+// retire()/silent_retire().
 struct CommandOptions {
   // A continuous poll lives in the queue until cancelled or failed; ignored for mutating codes.
   bool continuous{false};
@@ -135,17 +121,13 @@ struct ModbusDeviceCommand {
   ModbusClientDevice *device;
   ModbusFrame frame;
   // Place-in-line stamp (hub's free-running counter); selection takes the oldest for round-robin
-  // fairness within a class. Meant to wrap. Declared ahead of the byte fields so the tail packs
-  // densely and a growing CommandOptions eats trailing padding before enlarging the struct.
+  // fairness within a class. Meant to wrap.
   uint16_t seq{0};
   FrameState state{FrameState::READY};
   // Accepted requests this entry stands for, capped at max_pending(); drains one terminal each.
   // A continuous poll is a subscription: pending fixed at 1, removed only by cancellation or failure.
   uint8_t pending{1};
-  // The entry's LIVE effective options, not a record of the caller's request: queue_pdu() normalizes
-  // before storing, duplicate absorption mutates continuous via make_continuous(), and retire() resets
-  // the struct (silent_retire() leaves it, relying on the sweep to erase the entry). See the
-  // CommandOptions comment for the rules a new field must define.
+  // The entry's LIVE effective options, not a record of the caller's request
   CommandOptions options;
 
   // Build a command from a PDU span (caller bounds it to MAX_PDU_SIZE) and pre-normalized options;
@@ -154,28 +136,22 @@ struct ModbusDeviceCommand {
                       CommandOptions options = {}, uint16_t seq = 0)
       : device(device), frame(address, pdu.data(), static_cast<uint16_t>(pdu.size())), seq(seq), options(options) {}
 
-  // Transmit ordering class, derived (never stored): a continuous poll ranks below every one-shot.
   CommandPriority priority() const {
-    return this->options.continuous ? CommandPriority::CONTINUOUS : classify(this->frame.pdu()[0]);
-  }
-  // Wire-derived class: mutating codes rank WRITE; exception-flagged codes are excluded.
-  static CommandPriority classify(uint8_t function_code) {
-    if (helpers::is_function_code_exception(function_code))
-      return CommandPriority::READ;
-    if (helpers::is_function_code_write(function_code)) {
+    if (this->options.continuous)
+      return CommandPriority::CONTINUOUS;
+    if (helpers::is_function_code_write(this->frame.pdu()[0])) {
       return CommandPriority::WRITE;
     }
     return CommandPriority::READ;
   }
 
-  // Requests this entry can serve: a standard read twice (run plus one re-run), everything else once.
+  // Requests this entry can serve
   uint8_t max_pending() const {
     const uint8_t fc = this->frame.pdu()[0];
-    const bool requeueable = !helpers::is_function_code_exception(fc) && helpers::is_function_code_read_only(fc);
-    return (requeueable && !this->options.continuous) ? 2 : 1;
+    return (helpers::is_function_code_read_only(fc) && !this->options.continuous) ? 2 : 1;
   }
-  // Device-scoped clear: detach with no callback (device-less, pending 0). An entry still waiting for
-  // a response keeps its state as a reply-ignoring shell that resolves silently; any other goes RETIRED.
+  // Device-scoped clear: detach with no callback. An entry still waiting for a response keeps its state as a
+  // reply-ignoring shell that resolves silently; any other goes RETIRED.
   void silent_retire() {
     if (!this->waiting_state())
       this->state = FrameState::RETIRED;
@@ -183,28 +159,18 @@ struct ModbusDeviceCommand {
     this->device = nullptr;
   }
   // Fire-and-forget completion for a broadcast (address 0): the frame was transmitted (on_sent already
-  // fired), but a broadcast is never answered (Modbus 4.1), so the entry retires with NO terminal
-  // callback and the sweep erases it. Unlike response()/error()/timed_out(), it delivers nothing.
-  // A broadcast only carries a write or a custom code (reads are refused at queue_pdu()), and every such
-  // code caps pending at 1, so pending is always 1 here - clear it.
+  // fired), but a broadcast is never answered (Modbus 4.1), so the entry retires with no terminal callback.
   void complete_broadcast() {
     this->state = FrameState::RETIRED;
     this->pending = 0;
   }
-  // Re-ready for another transmission, restamped to the tail of its class (hub passes next_seq_++).
+  // Re-ready for another transmission, restamped to the tail of its class
   void requeue(uint16_t seq) {
     this->state = FrameState::READY;
     this->seq = seq;
   }
   // Re-task a frame that lives on: upgrade a one-shot to a continuous poll, or downgrade a poll back to
-  // a one-shot. Either way the entry keeps running and owes a request, so this is not a plain setter -
-  // to tear an entry down instead, use retire()/silent_retire(), which leave pending as the count owed.
-  // On: the entry becomes a continuous poll, superseding any absorbed requests (pending resets to the
-  // single subscription). Off: a one-shot duplicate has cancelled the poll, but the entry must still run
-  // once to serve that request - so restore one first. While the flag is still set max_pending() is 1,
-  // so the restore lifts a terminated poll (pending 0, after an error/timeout) back to 1 and is a no-op
-  // on a live poll already at 1; the flag drops afterwards, when a read's cap can widen to 2 without
-  // retroactively inflating that no-op.
+  // a one-shot.
   void make_continuous(bool continuous) {
     if (continuous) {
       this->options.continuous = true;
@@ -214,13 +180,9 @@ struct ModbusDeviceCommand {
       this->options.continuous = false;
     }
   }
-  // Address-scoped clear: keep pending and device so the sweep delivers one on_not_sent() per un-run
+  // Address-scoped clear: keep pending and device so the sweep delivers one on_not_sent() per un-delivered
   // request. An entry still waiting for a response keeps its in-flight request (whose usual terminal is
-  // still coming) and drains only its duplicates: WAITING -> WAITING_RETIRED, and INTERRUPTED ->
-  // INTERRUPTED_RETIRED which keeps distrusting late frames (they were already interrupted). Any other
-  // state -> RETIRED, draining everything. A cleared frame that then times out still honors a retry:
-  // the clear is address-scoped (any device may call it) while the retry is the owning device's call
-  // via on_no_response - the bus obeys the owner.
+  // still coming) and drains only its duplicates.
   void retire() {
     if (this->state == FrameState::WAITING) {
       this->state = FrameState::WAITING_RETIRED;
@@ -229,10 +191,10 @@ struct ModbusDeviceCommand {
     } else if (!this->waiting_state()) {  // an already-retired shell stays put; off the wire -> RETIRED
       this->state = FrameState::RETIRED;
     }
-    this->options = {};  // reset every option so a future field is torn down without editing here
+    this->options = {};  // reset every option
   }
 
-  // True while the entry is still waiting for a response; the erase pass exempts these even at pending 0.
+  // True while the entry is still waiting for a response
   bool waiting_state() const {
     return this->state == FrameState::WAITING || this->state == FrameState::INTERRUPTED ||
            this->state == FrameState::WAITING_RETIRED || this->state == FrameState::INTERRUPTED_RETIRED;
@@ -245,7 +207,7 @@ struct ModbusDeviceCommand {
     }
     return false;
   }
-  // Add one request, honouring the cap; false = already at cap (absorb a duplicate, restore a retry).
+
   bool increment_pending() {
     if (this->pending < this->max_pending()) {
       this->pending++;
@@ -255,7 +217,7 @@ struct ModbusDeviceCommand {
   }
 
   // Terminal/lifecycle methods: each owns its transition, callback, and pending accounting and
-  // returns whether a callback ran. Out-of-line: ModbusClientDevice is incomplete here.
+  // returns whether a callback ran.
   bool sent();
   bool response(std::span<const uint8_t> response_pdu);
   bool error(ExceptionCode exception_code);
@@ -264,9 +226,6 @@ struct ModbusDeviceCommand {
   bool notify_retired();
 
   /// True if this command carries the same wire frame (address + PDU) as the given one.
-  /// Cancellation matches the exact frame, not the action instance: a continuous poll whose
-  /// start_address (or other field) is templated produces one poll per distinct frame, and a later
-  /// cancel built from different argument values will not reach the polls it does not byte-match.
   bool same_frame(uint8_t address, std::span<const uint8_t> pdu) const {
     const auto own_pdu = this->frame.pdu();
     return own_pdu.size() == pdu.size() && this->frame.address() == address &&
@@ -279,8 +238,9 @@ class ModbusClientHub : public Modbus {
   ModbusClientHub() = default;
   void dump_config() override;
   void loop() override;
-  void set_send_wait_time(uint16_t time_in_ms) { this->send_wait_time_ = time_in_ms; }
-  void set_turnaround_time(uint16_t time_in_ms) { this->turnaround_delay_ms_ = time_in_ms; }
+  // Config arrives in milliseconds; stored internally in microseconds like all other timing.
+  void set_send_wait_time(uint16_t time_in_ms) { this->send_wait_time_us_ = time_in_ms * 1000UL; }
+  void set_turnaround_time(uint16_t time_in_ms) { this->turnaround_delay_us_ = time_in_ms * 1000UL; }
   bool tx_buffer_empty();
   bool tx_blocked() override;
   ESPDEPRECATED("Use queue_pdu() with create_client_pdu() instead. Removed in 2026.10.0", "2026.4.0")
@@ -291,17 +251,13 @@ class ModbusClientHub : public Modbus {
                                                payload_len),
                     device);
   };
-  /// Queue a request. The name says queue, not send: the frame is appended to the transmit queue and
-  /// goes out later from loop(), so a true return means accepted into the machine (it will resolve in
-  /// exactly one terminal callback - except a broadcast (address 0), which is never answered and so gets
-  /// only on_sent()), NOT that anything reached the wire - that is on_sent(). False means
-  /// it never entered the machine at all (empty or oversize PDU, full queue, anonymous or over-cap
-  /// duplicate) and no callback of any kind will follow; the false return is the whole story.
+  /// Queue a request. True = accepted: it resolves in exactly one terminal callback (a broadcast,
+  /// address 0, gets only on_sent()). False = refused, and no callback of any kind follows.
+  /// Neither means anything reached the wire - on_sent() reports that.
   bool queue_pdu(uint8_t address, std::span<const uint8_t> pdu, ModbusClientDevice *device = nullptr,
                  CommandOptions options = {});
-  // Remove before 2027.2.0. Deliberately the signature 2026.7.4 shipped - void, and no CommandOptions:
-  // the bool return and the options argument arrived after that release, so nothing external can be
-  // relying on them under this name. Callers who want the queued/refused answer move to queue_pdu().
+  // Remove before 2027.2.0. Deliberately the void, no-options signature 2026.7.4 shipped: nothing
+  // external can rely on the later additions under this name.
   ESPDEPRECATED("Use queue_pdu() instead - the call queues a request, it does not send one, and it "
                 "reports whether the request was accepted. Removed in 2027.2.0",
                 "2026.8.0")
@@ -310,9 +266,10 @@ class ModbusClientHub : public Modbus {
   }
   ESPDEPRECATED("Use queue_pdu(payload[0], <pdu bytes>, device) instead. Removed in 2027.2.0", "2026.8.0")
   void send_raw(const std::vector<uint8_t> &payload, ModbusClientDevice *device = nullptr);
-  // Clear an address's commands; each un-run request resolves via on_not_sent(), but a frame on the
-  // wire still runs to its usual terminal. clear_tx_queue_for_device() instead discards silently.
+  // Clear all commands matching the given address; each unsent request resolves via on_not_sent(), but a
+  // frame on the wire still runs to its usual terminal.
   void clear_tx_queue_for_address(uint8_t address);
+  // Clear all commands for a given device; no callbacks are delivered.
   void clear_tx_queue_for_device(ModbusClientDevice *device);
 
  protected:
@@ -322,16 +279,15 @@ class ModbusClientHub : public Modbus {
   void send_next_frame_();
   // Deliver owed callbacks from a quiescent hub and apply lifecycle bookkeeping; see FrameState.
   void sweep_();
-  // The selection function: best READY entry (WRITE class first, then one-shot reads, then the
-  // least-recently-served continuous; FIFO by seq within each group), or nullptr.
+  // The selection function: best READY entry (ordered by priority; FIFO by seq within each group), or nullptr.
   ModbusDeviceCommand *select_next_ready_();
   // Locate the single entry waiting for a response (WAITING/INTERRUPTED/WAITING_RETIRED/INTERRUPTED_RETIRED).
   ModbusDeviceCommand *find_waiting_();
   // End the wait for a response on send-wait timeout (the loop() watchdog body); see FrameState.
   void expire_waiting_();
 
-  uint16_t send_wait_time_{2000};
-  uint16_t turnaround_delay_ms_{0};
+  uint32_t send_wait_time_us_{2000000};
+  uint32_t turnaround_delay_us_{0};
 
   // Set on transmit, cleared on the transaction-ending transition; send_next_frame_ won't select
   // while it is set, so at most one frame is awaiting a response.
@@ -349,13 +305,10 @@ class ModbusClientHub : public Modbus {
 // Transaction status: std::nullopt on success, otherwise a Modbus exception code
 using ResponseStatus = std::optional<ExceptionCode>;
 
-/// True when a transaction carried no exception. The optional holds the exception, so has_value() means
-/// the request FAILED - the inverse of how "status" usually reads. Prefer this at the call site; the
-/// bare !status.has_value() has already been mistaken for a failure check more than once. Where the code
-/// is going to unwrap the exception anyway, status.has_value() followed by status.value() stays clearer.
+/// True when a transaction carried no exception.
 inline bool succeeded(ResponseStatus status) { return !status.has_value(); }
 
-// Register values exchanged with server handlers, in host byte order. Sized at the larger of the two protocol
+// Register values exchanged with server handlers, in address order. Sized at the larger of the two protocol
 // maxima (read = 125 / 0x7D, write = 123 / 0x7B); the per-direction count limit is enforced by the hub, not by
 // the capacity of this type.
 using RegisterValues = StaticVector<uint16_t, MAX_NUM_OF_REGISTERS_TO_READ>;
@@ -373,59 +326,46 @@ class ModbusServerHub : public Modbus {
   void process_modbus_client_frame_(uint8_t address, uint8_t function_code, std::span<const uint8_t> data);
   // Dispatches a broadcast (address 0) write to every registered device; broadcasts are never answered.
   void process_broadcast_frame_(uint8_t function_code, std::span<const uint8_t> data);
-  // Parses a WRITE_SINGLE_REGISTER / WRITE_MULTIPLE_REGISTERS PDU into start_address and the host-order register
-  // values, validating the register count and address range. Returns std::nullopt on success, otherwise the Modbus
-  // exception code describing the failure. Shared by unicast writes (which reply with the exception) and broadcast
-  // writes (which silently drop invalid frames).
+  // Parses a WRITE_SINGLE_REGISTER / WRITE_MULTIPLE_REGISTERS PDU into start_address and the address order register
+  // values, validating the register count and address range. Shared by unicast and broadcast writes.
   ResponseStatus parse_write_single_(std::span<const uint8_t> data, uint16_t &start_address, RegisterValues &registers);
   ResponseStatus parse_write_multiple_(std::span<const uint8_t> data, uint16_t &start_address,
                                        RegisterValues &registers);
-  // Appends the big-endian register values in values to registers, in host byte order.
+  // Assembles host-order registers from the big-endian bytes in values and appends them to registers.
   void assemble_registers_(std::span<const uint8_t> values, RegisterValues &registers);
   ModbusServerDevice *find_device_(uint8_t address);
-  // Returns std::nullopt if [start_address, start_address + count) fits in the 16-bit address space,
-  // otherwise ILLEGAL_DATA_ADDRESS. The caller sends the exception reply if one is required - a broadcast
-  // write is never answered, so the check cannot send it itself. Shared by the register and
-  // coil/discrete-input handlers, which all address the same 16-bit space.
+  // Returns std::nullopt if [start_address, start_address + count) fits in a 16-bit address space, otherwise
+  // ILLEGAL_DATA_ADDRESS. The caller sends the exception reply if one is required. Shared by the
+  // register/coil/discrete-input handlers, which all use a 16-bit address space.
   ResponseStatus check_address_range_(uint16_t start_address, uint16_t count);
 
-  // Parses a read request PDU (start address(2) + quantity(2)), shared by the register and
-  // coil/discrete-input reads so the two cannot drift apart. max_entities is the protocol ceiling for the
-  // function code; entity_name only labels the rejection log.
+  // Parses read request data. max_entities is the protocol ceiling for the function code; entity_name labels
+  // the rejection log.
   ResponseStatus parse_read_request_(std::span<const uint8_t> data, uint16_t max_entities, const LogString *entity_name,
                                      uint16_t &start_address, uint16_t &count);
 
-  // Parses a single-coil write PDU (FC 0x05), which carries a 2-byte on/off value rather than packed
-  // bytes. The caller packs value into a byte it owns to build the PackedBits view the handlers take.
+  // Parses single-coil write data
   ResponseStatus parse_write_single_coil_(std::span<const uint8_t> data, uint16_t &start_address, bool &value);
 
-  // Parses a multiple-coil write PDU (FC 0x0F) into a packed-bit view pointing straight into the receive
-  // buffer, so the coil values are never copied. Both coil parsers are shared by the addressed and
-  // broadcast paths so the two validate identically.
+  // Parses write-multiple-coil data into a packed-bit view pointing straight into the receive buffer, so the
+  // coil values are never copied.
   ResponseStatus parse_write_multiple_coils_(std::span<const uint8_t> data, uint16_t &start_address, uint16_t &count,
                                              std::span<const uint8_t> &packed_bytes);
 
-  // Builds the body of a register read response (byte count followed by the big-endian register values) into
-  // response_buffer. Shared by every function code that answers with register values, so the read reply stays
-  // identical across them. Returns false once an exception has been sent: the one the handler reported via
-  // status, or SERVICE_DEVICE_FAILURE if it returned the wrong number of registers, the count exceeds the
-  // protocol read limit, or the body does not fit.
+  // Builds the body of a register read response into response_buffer. Returns false once an exception has
+  // been sent: the one the handler reported via status, or SERVICE_DEVICE_FAILURE if it returned the wrong
+  // number of registers, the count exceeds the protocol read limit, or the body does not fit.
   bool build_or_reject_read_response_(uint8_t address, uint8_t function_code, ResponseStatus status,
                                       uint16_t number_of_registers, const RegisterValues &registers,
                                       std::span<uint8_t> response_buffer, uint16_t &response_len);
   void send_raw_(const uint8_t *payload, uint16_t len);
   // Sends and logs the exception reply when status holds one; returns true if the request was rejected.
-  // Every parse and handler rejection funnels through here, so the reply and its log cannot drift apart.
   bool rejected_(uint8_t address, uint8_t function_code, ResponseStatus status);
   void send_exception_(uint8_t address, uint8_t function_code, ExceptionCode exception_code);
   void send_response_(uint8_t address, uint8_t function_code, const uint8_t *payload, uint16_t payload_len);
   uint8_t expecting_peer_response_{0};
   std::vector<ModbusServerDevice *> devices_;
 
-  // Stamp of the last "broadcast reached no device" warning, 0 until the first one is logged. Rate limiting
-  // on time rather than on address keeps the log bounded no matter how many addresses a shared bus carries.
-  uint32_t last_unaccepted_broadcast_warn_{0};
-
   // Holds the raw payload of a single reply deferred for sending when tx was blocked at send time.
   // Only one server reply can be waiting at once, so a single fixed buffer avoids heap allocation.
   std::array<uint8_t, MAX_RAW_SIZE> deferred_payload_;
@@ -555,10 +495,7 @@ class ModbusClientDevice {
         helpers::create_client_pdu((FunctionCode) function, start_address, number_of_entities, payload, payload_len),
         this);
   }
-  /// See ModbusClientHub::queue_pdu(): true = accepted into the queue and a terminal callback will
-  /// follow (except a broadcast (address 0), which is never answered and so gets only on_sent()),
-  /// false = refused at the door and nothing further happens. Neither means the frame is on the wire;
-  /// on_sent() reports that.
+  /// See ModbusClientHub::queue_pdu() for the return contract.
   bool queue_pdu(std::span<const uint8_t> pdu, CommandOptions options = {}) {
     return this->parent_->queue_pdu(this->address_, pdu, this, options);
   }
@@ -573,11 +510,8 @@ class ModbusClientDevice {
       return;  // too short to contain a PDU; refused at the door like any invalid send
     this->parent_->queue_pdu(payload[0], std::span<const uint8_t>(payload).subspan(1), this);
   }
-  // The typed request builders below all queue through queue_pdu(), so they share its contract: true
-  // means the request is queued and will resolve in exactly one terminal callback (except a broadcast
-  // (address 0), which is never answered and so gets only on_sent()), false means it was refused outright
-  // with no callback. Neither says the frame has been transmitted - on_sent() does.
-  // Reads via the table-appropriate function code; an unreadable entity type maps to INVALID, which
+  // The typed request builders below all queue through queue_pdu() and share its return contract.
+  // Reads use the table-appropriate function code; an unreadable entity type maps to INVALID, which
   // create_read_pdu() rejects into an empty PDU and queue_pdu() refuses with a false return.
   bool read_entities(EntityType entity_type, uint16_t start_address, uint16_t number_of_entities,
                      CommandOptions options = {}) {
@@ -607,6 +541,9 @@ class ModbusClientDevice {
     return this->queue_pdu(helpers::create_write_single_coil_pdu(address, value));
   }
   bool write_multiple_registers(uint16_t start_address, std::span<const uint16_t> values) {
+    // Empty goes to the full-size builder so the rejection log names this method's limit, not the small one's.
+    if (!values.empty() && values.size() <= helpers::MAX_FEW_REGISTERS)
+      return this->queue_pdu(helpers::create_write_few_registers_pdu(start_address, values));
     return this->queue_pdu(helpers::create_write_registers_pdu(start_address, values));
   }
   /// Note: std::vector<bool> cannot bind to std::span<const bool>; use a contiguous bool container or the packed
@@ -619,11 +556,9 @@ class ModbusClientDevice {
   bool write_multiple_coils(uint16_t start_address, PackedBits bits) {
     return this->queue_pdu(helpers::create_write_coils_pdu(start_address, bits));
   }
-  /// FC 0x17: the read-back is delivered through on_read_holding_registers() (the response carries only the
-  /// read registers, the same wire shape as a holding-register read). A device exception - typically a
-  /// rejected write half - arrives at that same on_read_holding_registers() with the error in its status,
-  /// exactly as success does, so a subclass overriding that one callback handles both outcomes and never
-  /// needs to also override on_error().
+  /// FC 0x17: the read-back is delivered through on_read_holding_registers(), and a device exception
+  /// (typically a rejected write half) arrives there too via its status - one callback handles both
+  /// outcomes with no on_error() override needed.
   bool read_write_multiple_registers(uint16_t read_start_address, uint16_t read_count, uint16_t write_start_address,
                                      std::span<const uint16_t> write_values) {
     return this->queue_pdu(helpers::create_read_write_multiple_registers_pdu(read_start_address, read_count,
@@ -644,12 +579,9 @@ class ModbusClientDevice {
   bool custom_response_warned_{false};  // first unhandled custom response warns; repeats log at VERBOSE
 };
 
-// Compatibility shim for external components written against the pre-2026.8 API, which subclassed
-// ModbusDevice and overrode on_modbus_data()/on_modbus_error(). The name is free (nothing in-tree
-// uses it), so instead of a plain alias it adapts the new span-based hooks back to the old
-// signatures: on_modbus_data() receives the response payload as an owning vector (the heap copy
-// exists only on this deprecated path) and on_modbus_error() the function code and exception code.
-// Remove before 2027.2.0 (window restarted when the plain alias became a behavior shim in 2026.8.0)
+// Compatibility shim adapting the span-based hooks back to the pre-2026.8 on_modbus_data()/
+// on_modbus_error() signatures (the owning-vector heap copy exists only on this deprecated path).
+// Remove before 2027.2.0 (window restarted when the plain alias became a behavior shim in 2026.8.0).
 class ESPDEPRECATED("Subclass ModbusClientDevice and override on_response()/on_error() instead. Removed in 2027.2.0",
                     "2026.8.0") ModbusDevice : public ModbusClientDevice {
  public:

esphome/components/modbus/modbus_definitions.h

@@ -47,7 +47,6 @@ enum class FunctionCode : uint8_t {
 using ModbusFunctionCode ESPDEPRECATED("Use modbus::FunctionCode instead. Removed in 2027.2.0",
                                        "2026.8.0") = FunctionCode;
 
-/*Allow direct comparison operators between FunctionCode and uint8_t*/
 inline bool operator==(FunctionCode lhs, uint8_t rhs) { return static_cast<uint8_t>(lhs) == rhs; }
 inline bool operator==(uint8_t lhs, FunctionCode rhs) { return lhs == static_cast<uint8_t>(rhs); }
 inline bool operator!=(FunctionCode lhs, uint8_t rhs) { return !(static_cast<uint8_t>(lhs) == rhs); }
@@ -117,6 +116,9 @@ static constexpr uint16_t MAX_RAW_SIZE = 254;  // Max RAW size is 256 - CRC(2) =
 static constexpr uint16_t READ_PDU_SIZE = 5;
 // A single-write PDU is always function code(1) + address(2) + value(2)
 static constexpr uint16_t WRITE_SINGLE_PDU_SIZE = 5;
+// A multiple-write PDU starts with function code(1) + start address(2) + quantity(2) + byte count(1),
+// followed by two bytes per register.
+static constexpr uint16_t WRITE_MULTIPLE_HEADER_SIZE = 6;
 static constexpr uint16_t MAX_FRAME_SIZE = 256;
 
 // 4.1 Address 0 is the broadcast address: the request is processed by every device and never answered.

esphome/components/modbus/modbus_helpers.cpp

@@ -30,9 +30,11 @@ uint16_t server_pdu_length(const uint8_t *frame, size_t size) {
   switch (static_cast<FunctionCode>(frame[0])) {
     case FunctionCode::READ_COILS:
     case FunctionCode::READ_DISCRETE_INPUTS:
+      // function(1) + byte count(1) + packed coil bytes
+      return 2 + (size > 1 ? std::min(frame[1], uint8_t(packed_bit_bytes(MAX_NUM_OF_COILS_TO_READ))) : 0);
     case FunctionCode::READ_HOLDING_REGISTERS:
     case FunctionCode::READ_INPUT_REGISTERS:
-      // function(1) + byte count(1) + data
+      // function(1) + byte count(1) + register data
       return 2 + (size > 1 ? std::min(frame[1], uint8_t(MAX_NUM_OF_REGISTERS_TO_READ * 2)) : 0);
     case FunctionCode::WRITE_SINGLE_COIL:
     case FunctionCode::WRITE_SINGLE_REGISTER:
@@ -60,6 +62,9 @@ uint16_t server_pdu_length(const uint8_t *frame, size_t size) {
 uint16_t client_pdu_length(const uint8_t *frame, size_t size) {
   if (size < MIN_PDU_SIZE)
     return MIN_PDU_SIZE;
+  if (is_function_code_exception(frame[0])) {
+    return 2;  // never a valid request; sized like the exception reply so the CRC fails at once
+  }
   switch (static_cast<FunctionCode>(frame[0])) {
     case FunctionCode::READ_COILS:
     case FunctionCode::READ_DISCRETE_INPUTS:
@@ -287,25 +292,52 @@ std::optional<int64_t> payload_to_number(const uint8_t *data, size_t size, Senso
 }
 
 std::optional<int64_t> registers_to_number(const uint16_t *registers, size_t count, SensorValueType sensor_value_type) {
-  const size_t required_size = required_payload_size(sensor_value_type);
-  if (required_size == 0) {
-    return 0;  // RAW/unsupported: nothing to read
+  // RAW and BIT carry no fixed-width number, so there is nothing to decode whatever the span holds.
+  // register_width_for() reports 1 for them, so this must be checked before the width test below.
+  if (sensor_value_type == SensorValueType::RAW || sensor_value_type == SensorValueType::BIT) {
+    return 0;
   }
-  const size_t required_words = required_size / 2;
+  const uint16_t required_words = register_width_for(sensor_value_type);
   if (required_words > count) {
-    ESP_LOGE(TAG, "not enough registers for value type=%u count=%zu required=%zu",
-             static_cast<unsigned int>(sensor_value_type), count, required_words);
+    ESP_LOGE(TAG, "not enough registers for value type=%u count=%zu required=%u",
+             static_cast<unsigned int>(sensor_value_type), count, static_cast<unsigned int>(required_words));
     return std::nullopt;
   }
-  // Serialize the needed words back to big-endian bytes and reuse the audited byte decoder so the
-  // sign-extension behaviour stays identical to the wire path.
-  uint8_t bytes[8];  // at most 4 registers (QWORD)
-  for (size_t i = 0; i < required_words; i++) {
-    uint16_t reg = registers[i];
-    bytes[i * 2] = static_cast<uint8_t>(reg >> 8);
-    bytes[i * 2 + 1] = static_cast<uint8_t>(reg & 0xFF);
+  // Registers are the wire's own unit, so decode them directly rather than serializing back to bytes.
+  // Each case defers to registers_to_value() so the word order and sign rules have one definition, with
+  // two deliberate exceptions matching what the byte decoder returned: the float types yield their bit
+  // pattern rather than a float, and U_QWORD shares the signed branch because the return type is int64_t.
+  switch (sensor_value_type) {
+    case SensorValueType::U_WORD:
+      return registers_to_value<SensorValueType::U_WORD>(registers);
+    case SensorValueType::U_WORD_S:
+      return registers_to_value<SensorValueType::U_WORD_S>(registers);
+    case SensorValueType::S_WORD:
+      return registers_to_value<SensorValueType::S_WORD>(registers);
+    case SensorValueType::S_WORD_S:
+      return registers_to_value<SensorValueType::S_WORD_S>(registers);
+    case SensorValueType::U_DWORD:
+      return registers_to_value<SensorValueType::U_DWORD>(registers);
+    case SensorValueType::U_DWORD_R:
+      return registers_to_value<SensorValueType::U_DWORD_R>(registers);
+    case SensorValueType::S_DWORD:
+      return registers_to_value<SensorValueType::S_DWORD>(registers);
+    case SensorValueType::S_DWORD_R:
+      return registers_to_value<SensorValueType::S_DWORD_R>(registers);
+    case SensorValueType::FP32:
+      return registers_to_uint32(registers[0], registers[1]);
+    case SensorValueType::FP32_R:
+      return registers_to_uint32(registers[1], registers[0]);
+    // Signed for both: an unsigned QWORD above INT64_MAX has to come back as a negative int64_t.
+    case SensorValueType::U_QWORD:
+    case SensorValueType::S_QWORD:
+      return registers_to_value<SensorValueType::S_QWORD>(registers);
+    case SensorValueType::U_QWORD_R:
+    case SensorValueType::S_QWORD_R:
+      return registers_to_value<SensorValueType::S_QWORD_R>(registers);
+    default:
+      return 0;
   }
-  return payload_to_number(bytes, required_size, sensor_value_type, 0, 0xFFFFFFFF);
 }
 
 // Append a 16-bit value to a PDU in big-endian (wire) byte order.
@@ -381,8 +413,6 @@ ReadPdu create_read_pdu(FunctionCode function_code, uint16_t start_address, uint
 PduBuffer create_client_pdu(FunctionCode function_code, uint16_t start_address, uint16_t number_of_entities,
                             const uint8_t *values, size_t values_len) {
   PduBuffer pdu;  // declared before every return so NRVO fires (all paths return the same object)
-  // Generic entry point; prefer the direction- and type-specific builders (create_read_pdu(),
-  // create_write_registers_pdu(), etc.) which bound their inputs per spec.
   if (is_function_code_read_only(static_cast<uint8_t>(function_code))) {
     if (values != nullptr || values_len > 0) {
       ESP_LOGW(TAG, "Values provided for read function code %02X, but will be ignored",
@@ -445,9 +475,7 @@ PduBuffer create_client_pdu(FunctionCode function_code, uint16_t start_address,
     return pdu;
   }
   // The quantity is spec-bounded above, so the data length just has to agree with it exactly
-  // (registers are 2 bytes each, coils pack 8 per byte). This is the same consistency the response
-  // dispatch enforces via is_client_pdu_standard(), so a frame built here can never be classified
-  // non-standard on reply, and the spec bound keeps the PDU within capacity by construction.
+  // (registers are 2 bytes each, coils pack 8 per byte).
   // Checked before the header append: a failed check must return an empty PDU, not a 5-byte partial one.
   const bool bits = function_code == FunctionCode::WRITE_MULTIPLE_COILS;
   const size_t expected_len = bits ? packed_bit_bytes(number_of_entities) : static_cast<size_t>(number_of_entities) * 2;
@@ -484,9 +512,12 @@ static bool register_block_in_range(const LogString *role, uint16_t start_addres
   return true;
 }
 
-PduBuffer create_write_registers_pdu(uint16_t start_address, std::span<const uint16_t> values) {
-  PduBuffer pdu;  // declared before every return so NRVO fires (all paths return the same object)
-  if (!register_block_in_range(LOG_STR("Write"), start_address, values.size(), MAX_NUM_OF_REGISTERS_TO_WRITE)) {
+// The ceiling comes from the buffer itself: push_back() drops silently, so a bound wider than the buffer
+// would put a truncated frame on the wire.
+template<typename Pdu> static Pdu build_write_registers_pdu(uint16_t start_address, std::span<const uint16_t> values) {
+  constexpr auto max_registers = static_cast<uint16_t>((Pdu::capacity() - WRITE_MULTIPLE_HEADER_SIZE) / 2);
+  Pdu pdu;  // declared before every return so NRVO fires (all paths return the same object)
+  if (!register_block_in_range(LOG_STR("Write"), start_address, values.size(), max_registers)) {
     return pdu;
   }
   append_pdu_header(pdu, FunctionCode::WRITE_MULTIPLE_REGISTERS, start_address, values.size());
@@ -497,6 +528,19 @@ PduBuffer create_write_registers_pdu(uint16_t start_address, std::span<const uin
   return pdu;
 }
 
+static_assert((PduBuffer::capacity() - WRITE_MULTIPLE_HEADER_SIZE) / 2 == MAX_NUM_OF_REGISTERS_TO_WRITE,
+              "a full-frame PDU must hold exactly MAX_NUM_OF_REGISTERS_TO_WRITE registers");
+static_assert((WriteFewRegistersPdu::capacity() - WRITE_MULTIPLE_HEADER_SIZE) / 2 == MAX_FEW_REGISTERS,
+              "the small write buffer must hold exactly MAX_FEW_REGISTERS registers");
+
+PduBuffer create_write_registers_pdu(uint16_t start_address, std::span<const uint16_t> values) {
+  return build_write_registers_pdu<PduBuffer>(start_address, values);
+}
+
+WriteFewRegistersPdu create_write_few_registers_pdu(uint16_t start_address, std::span<const uint16_t> values) {
+  return build_write_registers_pdu<WriteFewRegistersPdu>(start_address, values);
+}
+
 PduBuffer create_read_write_multiple_registers_pdu(uint16_t read_start_address, uint16_t read_count,
                                                    uint16_t write_start_address,
                                                    std::span<const uint16_t> write_values) {

esphome/components/modbus/modbus_helpers.h

@@ -60,14 +60,11 @@ inline bool is_function_code_custom(uint8_t function_code) {
 /// in step with those switches). Deliberately wider than is_function_code_custom(): the user-defined
 /// ranges are unknown to the parser too, but so are the assigned-but-unimplemented codes
 /// (READ_EXCEPTION_STATUS, DIAGNOSTICS, GET_COMM_EVENT_*, REPORT_SERVER_ID) and every unassigned value.
-/// The 0x80 exception flag is masked off first, so a frame with it set classifies by its base code -
-/// even though a spec exception reply has a known 2-byte PDU. That is deliberate, matching what
-/// is_function_code_custom() has always done: some vendors use codes with the 0x80 bit set as ordinary
-/// codes with longer payloads, so the response parser CRC-scans these rather than assuming the spec
-/// length. For an intact spec exception the scan matches at its first candidate, so only a corrupt one
-/// pays (recovery by timeout instead of an immediate CRC failure).
+/// Exception-flagged codes (0x80 set) are always the 2-byte spec exception shape, so never unknown.
 inline bool is_function_code_unknown_length(uint8_t function_code) {
-  switch (static_cast<FunctionCode>(function_code & FUNCTION_CODE_MASK)) {
+  if (is_function_code_exception(function_code))
+    return false;
+  switch (static_cast<FunctionCode>(function_code)) {
     case FunctionCode::READ_COILS:
     case FunctionCode::READ_DISCRETE_INPUTS:
     case FunctionCode::READ_HOLDING_REGISTERS:
@@ -87,6 +84,17 @@ inline bool is_function_code_unknown_length(uint8_t function_code) {
   }
 }
 
+/// True when the underlying function code (exception bit masked off) may be broadcast (address 0).
+/// Refused: the reads (including read-write), plus every other code whose response length the parser
+/// knows (file record, FIFO). Allowed: the writes, and any code the parser does not know, since the
+/// hub cannot tell one of those apart from a vendor write.
+inline bool is_function_code_broadcastable(uint8_t function_code) {
+  uint8_t masked_function_code = function_code & FUNCTION_CODE_MASK;
+  if (is_function_code_read(masked_function_code))
+    return false;
+  return is_function_code_write(masked_function_code) || is_function_code_unknown_length(masked_function_code);
+}
+
 // Returns the expected length of a server response PDU based on the function code.
 // If too few bytes have arrived to determine the length, returns the minimum length. `size` is the
 // number of bytes available so far, which may exceed the eventual PDU (e.g. include the frame's CRC
@@ -205,7 +213,7 @@ enum class SensorValueType : uint8_t {
   S_DWORD = 0x4,  // 2 Registers signed
   BIT = 0x5,
   U_DWORD_R = 0x6,  // 2 Registers unsigned
-  S_DWORD_R = 0x7,  // 2 Registers unsigned
+  S_DWORD_R = 0x7,  // 2 Registers signed
   U_QWORD = 0x8,
   S_QWORD = 0x9,
   U_QWORD_R = 0xA,
@@ -220,6 +228,26 @@ inline bool value_type_is_float(SensorValueType v) {
   return v == SensorValueType::FP32 || v == SensorValueType::FP32_R;
 }
 
+/// Number of 16-bit registers a value of this type occupies (RAW counts as one register).
+constexpr uint16_t register_width_for(SensorValueType v) {
+  switch (v) {
+    case SensorValueType::U_DWORD:
+    case SensorValueType::S_DWORD:
+    case SensorValueType::U_DWORD_R:
+    case SensorValueType::S_DWORD_R:
+    case SensorValueType::FP32:
+    case SensorValueType::FP32_R:
+      return 2;
+    case SensorValueType::U_QWORD:
+    case SensorValueType::S_QWORD:
+    case SensorValueType::U_QWORD_R:
+    case SensorValueType::S_QWORD_R:
+      return 4;
+    default:
+      return 1;
+  }
+}
+
 /// Coils and discrete inputs are the bit-addressed entity tables; the other types are 16-bit registers.
 inline bool is_entity_type_binary(EntityType type) {
   return type == EntityType::COIL || type == EntityType::DISCRETE_INPUT;
@@ -260,7 +288,7 @@ inline uint8_t c_to_hex(char c) { return (c >= 'A') ? (c >= 'a') ? (c - 'a' + 10
  *  byte_from_hex_str("1122", 1) returns uint_8 value 0x22 == 34
  *  byte_from_hex_str("1122", 0) returns 0x11
  * @param value string containing hex encoding
- * @param position  offset in bytes. Because each byte is encoded in 2 hex digits the position of the original byte in
+ * @param pos  offset in bytes. Because each byte is encoded in 2 hex digits the position of the original byte in
  * the hex string is byte_pos * 2
  * @return byte value
  */
@@ -272,8 +300,7 @@ inline uint8_t byte_from_hex_str(const std::string &value, uint8_t pos) {
 
 /** Get a word from a hex string
  * @param value string containing hex encoding
- * @param position  offset in bytes. Because each byte is encoded in 2 hex digits the position of the original byte in
- * the hex string is byte_pos * 2
+ * @param pos offset in bytes (see byte_from_hex_str)
  * @return word value
  */
 inline uint16_t word_from_hex_str(const std::string &value, uint8_t pos) {
@@ -282,8 +309,7 @@ inline uint16_t word_from_hex_str(const std::string &value, uint8_t pos) {
 
 /** Get a dword from a hex string
  * @param value string containing hex encoding
- * @param position  offset in bytes. Because each byte is encoded in 2 hex digits the position of the original byte in
- * the hex string is byte_pos * 2
+ * @param pos offset in bytes (see byte_from_hex_str)
  * @return dword value
  */
 inline uint32_t dword_from_hex_str(const std::string &value, uint8_t pos) {
@@ -292,8 +318,7 @@ inline uint32_t dword_from_hex_str(const std::string &value, uint8_t pos) {
 
 /** Get a qword from a hex string
  * @param value string containing hex encoding
- * @param position  offset in bytes. Because each byte is encoded in 2 hex digits the position of the original byte in
- * the hex string is byte_pos * 2
+ * @param pos offset in bytes (see byte_from_hex_str)
  * @return qword value
  */
 inline uint64_t qword_from_hex_str(const std::string &value, uint8_t pos) {
@@ -308,9 +333,9 @@ template<typename T> T get_data(const std::vector<uint8_t> &data, size_t buffer_
  * Responses for coil are packed into bytes .
  * coil 3 is bit 3 of the first response byte
  * coil 9 is bit 2 of the second response byte
- * @param coil number of the cil
+ * @param bit index of the bit to extract
  * @param data modbus response buffer (uint8_t)
- * @return content of coil register
+ * @return value of the requested bit
  */
 inline bool bit_from_packed(int bit, std::span<const uint8_t> data) {
   auto data_byte = bit / 8;
@@ -448,11 +473,96 @@ inline int64_t payload_to_number(const std::vector<uint8_t> &data, SensorValueTy
  */
 std::optional<int64_t> registers_to_number(const uint16_t *registers, size_t count, SensorValueType sensor_value_type);
 
+/// Combine two register words into a 32-bit value.
+constexpr uint32_t registers_to_uint32(uint16_t high_word, uint16_t low_word) {
+  return (static_cast<uint32_t>(high_word) << 16) | low_word;
+}
+
+/// Combine four register words into a 64-bit value, most significant word first.
+constexpr uint64_t registers_to_uint64(uint16_t word0, uint16_t word1, uint16_t word2, uint16_t word3) {
+  return (static_cast<uint64_t>(registers_to_uint32(word0, word1)) << 32) | registers_to_uint32(word2, word3);
+}
+
+// Always false, whatever the type: it exists only to make the static_assert below depend on the
+// template argument. Not a queryable trait.
+template<SensorValueType> inline constexpr bool VALUE_TYPE_SUPPORTED = false;
+
+/** Decode one value whose type is known at compile time, from registers in host byte order.
+ * Unlike registers_to_number(), the type is a template argument, so only the one decode is compiled
+ * and the caller gets the value's natural type back rather than an int64_t. The "_R" types take the
+ * low word first; the rest take the high word first.
+ * Supports every fixed-width type: the WORD, DWORD, QWORD and FP32 families, including their _S and
+ * _R forms. RAW and BIT have no fixed width and fail to compile.
+ * Use register_width_for() for the number of registers the caller must supply.
+ * Note that the FP32 branches are only usable in a constant expression where std::bit_cast is
+ * available; elsewhere bit_cast falls back to a non-constexpr memcpy (see core/helpers.h).
+ */
+template<SensorValueType VALUE_TYPE> constexpr auto registers_to_value(const uint16_t *registers) {
+  if constexpr (VALUE_TYPE == SensorValueType::U_WORD) {
+    return registers[0];
+  } else if constexpr (VALUE_TYPE == SensorValueType::S_WORD) {
+    return static_cast<int16_t>(registers[0]);
+  } else if constexpr (VALUE_TYPE == SensorValueType::U_WORD_S) {
+    return byteswap(registers[0]);
+  } else if constexpr (VALUE_TYPE == SensorValueType::S_WORD_S) {
+    return static_cast<int16_t>(byteswap(registers[0]));
+  } else if constexpr (VALUE_TYPE == SensorValueType::U_DWORD) {
+    return registers_to_uint32(registers[0], registers[1]);
+  } else if constexpr (VALUE_TYPE == SensorValueType::U_DWORD_R) {
+    return registers_to_uint32(registers[1], registers[0]);
+  } else if constexpr (VALUE_TYPE == SensorValueType::S_DWORD) {
+    return static_cast<int32_t>(registers_to_uint32(registers[0], registers[1]));
+  } else if constexpr (VALUE_TYPE == SensorValueType::S_DWORD_R) {
+    return static_cast<int32_t>(registers_to_uint32(registers[1], registers[0]));
+  } else if constexpr (VALUE_TYPE == SensorValueType::FP32) {
+    return bit_cast<float>(registers_to_uint32(registers[0], registers[1]));
+  } else if constexpr (VALUE_TYPE == SensorValueType::FP32_R) {
+    return bit_cast<float>(registers_to_uint32(registers[1], registers[0]));
+  } else if constexpr (VALUE_TYPE == SensorValueType::U_QWORD) {
+    return registers_to_uint64(registers[0], registers[1], registers[2], registers[3]);
+  } else if constexpr (VALUE_TYPE == SensorValueType::U_QWORD_R) {
+    return registers_to_uint64(registers[3], registers[2], registers[1], registers[0]);
+  } else if constexpr (VALUE_TYPE == SensorValueType::S_QWORD) {
+    return static_cast<int64_t>(registers_to_uint64(registers[0], registers[1], registers[2], registers[3]));
+  } else if constexpr (VALUE_TYPE == SensorValueType::S_QWORD_R) {
+    return static_cast<int64_t>(registers_to_uint64(registers[3], registers[2], registers[1], registers[0]));
+  } else {
+    static_assert(VALUE_TYPE_SUPPORTED<VALUE_TYPE>, "registers_to_value() does not support this value type");
+  }
+}
+
+/// The type registers_to_value() yields for a given value type. Distinct from modbus::RegisterValues,
+/// which is a container of raw words.
+template<SensorValueType VALUE_TYPE>
+using RegisterValueType = decltype(registers_to_value<VALUE_TYPE>(static_cast<const uint16_t *>(nullptr)));
+
+/** The value stored at an absolute register address, or nullopt when it is not wholly inside this
+ * response. Lets a device decode by address rather than by offset, so a poll split across several
+ * requests needs no extra bookkeeping: a value outside the response simply yields nullopt.
+ * @param registers the response registers, in host byte order
+ * @param start_address the address the response begins at
+ * @param address the address of the wanted value
+ */
+template<SensorValueType VALUE_TYPE>
+constexpr std::optional<RegisterValueType<VALUE_TYPE>> value_at(std::span<const uint16_t> registers,
+                                                                uint16_t start_address, uint16_t address) {
+  if (address < start_address)
+    return std::nullopt;
+  const size_t offset = static_cast<size_t>(address) - start_address;
+  if (offset + register_width_for(VALUE_TYPE) > registers.size())
+    return std::nullopt;
+  return registers_to_value<VALUE_TYPE>(registers.data() + offset);
+}
+
+/// The widest standard numeric value (a QWORD) spans 4 registers, so one entity value never writes more.
+static constexpr uint16_t MAX_FEW_REGISTERS = 4;
+
 // Named PDU buffer types: the builders' storage strategy (currently stack-allocated StaticVector,
 // right-sized per shape) can be swapped in one place without touching every signature.
 using PduBuffer = StaticVector<uint8_t, MAX_PDU_SIZE>;
 using ReadPdu = StaticVector<uint8_t, READ_PDU_SIZE>;
 using WriteSinglePdu = StaticVector<uint8_t, WRITE_SINGLE_PDU_SIZE>;
+using WriteFewRegistersPdu = StaticVector<uint8_t, WRITE_MULTIPLE_HEADER_SIZE + 2 * MAX_FEW_REGISTERS>;
 /// Scratch space for packing coils into wire layout: one bit per coil, sized for the spec maximum.
 using CoilPackBuffer = StaticVector<uint8_t, packed_bit_bytes(MAX_NUM_OF_COILS_TO_WRITE)>;
 
@@ -496,6 +606,15 @@ PduBuffer create_client_pdu(FunctionCode function_code, uint16_t start_address,
  */
 PduBuffer create_write_registers_pdu(uint16_t start_address, std::span<const uint16_t> values);
 
+/** Create modbus write multiple registers command (function 0x10) on a right-sized stack buffer.
+ * Identical wire bytes to create_write_registers_pdu() for any accepted input.
+ * @param start_address modbus address of the first register to write
+ * @param values register values to write, at most MAX_FEW_REGISTERS (an over-long or empty set is
+ *               rejected and an empty PDU is returned)
+ * @return PDU (function code + data, no address, no CRC)
+ */
+WriteFewRegistersPdu create_write_few_registers_pdu(uint16_t start_address, std::span<const uint16_t> values);
+
 /** Create modbus read/write multiple registers command
  *  Function 0x17 Read/Write Multiple Registers
  * Writes write_values then reads read_count registers in one transaction (write first, per Modbus 6.17);

esphome/components/modbus_controller/__init__.py

@@ -41,6 +41,7 @@ from .const import (
     CONF_REGISTER_COUNT,
     CONF_REGISTER_TYPE,
     CONF_RESPONSE_SIZE,
+    CONF_REUSE_PREVIOUS_RANGE,
     CONF_SERVER_COURTESY_RESPONSE,
     CONF_SERVER_REGISTERS,
     CONF_SKIP_UPDATES,
@@ -60,6 +61,13 @@ ModbusController = modbus_controller_ns.class_("ModbusController", cg.PollingCom
 
 SensorItem = modbus_controller_ns.struct("SensorItem")
 
+RangeReuse = modbus_controller_ns.enum("RangeReuse", is_class=True)
+RANGE_REUSE = {
+    "auto": RangeReuse.AUTO,
+    True: RangeReuse.ALWAYS,
+    False: RangeReuse.NEVER,
+}
+
 _LOGGER = logging.getLogger(__name__)
 
 
@@ -184,13 +192,88 @@ ModbusItemBaseSchema = cv.Schema(
         ): cv.positive_int,
         cv.Optional(CONF_BITMASK, default=0xFFFFFFFF): cv.hex_uint32_t,
         cv.Optional(CONF_SKIP_UPDATES): validate_skip_updates_deprecated,
-        cv.Optional(CONF_FORCE_NEW_RANGE, default=False): cv.boolean,
+        cv.Optional(CONF_REUSE_PREVIOUS_RANGE, default="auto"): cv.Any(
+            cv.boolean, cv.one_of("auto", lower=True)
+        ),
+        # Deprecated options, migrated by validate_range_reuse_migration(). Remove before 2027.3.0
+        cv.Optional(CONF_FORCE_NEW_RANGE): cv.boolean,
+        cv.Optional(CONF_REGISTER_COUNT): cv.positive_int,
         cv.Optional(CONF_LAMBDA): cv.returning_lambda,
-        cv.Optional(CONF_RESPONSE_SIZE, default=0): cv.positive_int,
+        cv.Optional(CONF_RESPONSE_SIZE, default=0): cv.int_range(min=0, max=250),
     },
 )
 
 
+def _derived_register_widths(config: ConfigType) -> set[int]:
+    """Register widths an item derives on its own; a matching register_count is redundant."""
+    response_size = config.get(CONF_RESPONSE_SIZE, 0)
+    if (value_type := config.get(CONF_VALUE_TYPE)) is not None:
+        widths = {TYPE_REGISTER_MAP[value_type]}
+        if value_type == "RAW" and response_size > 0:
+            widths.add((response_size + 1) // 2)
+        return widths
+    if response_size > 0:
+        # text sensors: the old default was floor(response_size / 2); the derived width is now ceil
+        return {response_size // 2, (response_size + 1) // 2}
+    return {1}
+
+
+def entity_label(config: ConfigType) -> str:
+    """The entity's name or id, so migration messages say which entry to edit."""
+    label = config.get(CONF_NAME) or config.get(CONF_ID)
+    return str(label) if label is not None else "<unnamed>"
+
+
+# Remove before 2027.3.0
+def validate_range_reuse_migration(config: ConfigType) -> ConfigType:
+    """Migrate the removed force_new_range/register_count options to reuse_previous_range."""
+    if (force_new_range := config.pop(CONF_FORCE_NEW_RANGE, None)) is not None:
+        if config[CONF_REUSE_PREVIOUS_RANGE] != "auto":
+            raise cv.Invalid(
+                f"'{CONF_FORCE_NEW_RANGE}' and '{CONF_REUSE_PREVIOUS_RANGE}' can't be used together; "
+                f"remove '{CONF_FORCE_NEW_RANGE}'"
+            )
+        if force_new_range:
+            _LOGGER.warning(
+                "%s: '%s' is deprecated; '%s: false' replaces it but only stops this entity joining "
+                "the PREVIOUS range - set it on the following entity too if the range must stay "
+                "isolated. Removed in 2027.3.0",
+                entity_label(config),
+                CONF_FORCE_NEW_RANGE,
+                CONF_REUSE_PREVIOUS_RANGE,
+            )
+            config[CONF_REUSE_PREVIOUS_RANGE] = False
+        else:
+            _LOGGER.warning(
+                "%s: '%s: false' has no effect; remove it. Removed in 2027.3.0",
+                entity_label(config),
+                CONF_FORCE_NEW_RANGE,
+            )
+    if (register_count := config.pop(CONF_REGISTER_COUNT, None)) is not None:
+        if (
+            register_count not in _derived_register_widths(config)
+            and register_count != 0
+        ):
+            raise cv.Invalid(
+                f"'{CONF_REGISTER_COUNT}' has been removed; the number of registers to read is now "
+                f"derived from '{CONF_VALUE_TYPE}' (or '{CONF_RESPONSE_SIZE}' for RAW values and text "
+                f"sensors). To make one request span extra registers up to the next sensor, set "
+                f"'{CONF_REUSE_PREVIOUS_RANGE}: true' on the NEXT sensor instead; for RAW or text block "
+                f"reads set '{CONF_RESPONSE_SIZE}' to the byte count; to force multi-register writes set "
+                f"'use_write_multiple: true'. See "
+                "https://esphome.io/components/modbus_controller/"
+            )
+        _LOGGER.warning(
+            "%s: '%s' is now derived from '%s' (or '%s' for RAW values and text sensors) and has no "
+            "effect; remove it. Removed in 2027.3.0",
+            entity_label(config),
+            CONF_REGISTER_COUNT,
+            CONF_VALUE_TYPE,
+            CONF_RESPONSE_SIZE,
+        )
+    return config
+
+
 def validate_modbus_register(config: ConfigType) -> ConfigType:
     # custom_command is the deprecated alias for custom_pdu (migrated later in final validate); treat
     # either as "a custom frame is configured" so the address/register_type rules match.
@@ -293,20 +376,13 @@ def reject_odd_holding_write_offset(config: ConfigType) -> ConfigType:
     return config
 
 
-def modbus_calc_properties(config: ConfigType) -> tuple[int, int]:
+def modbus_calc_properties(config: ConfigType) -> int:
     byte_offset = 0
-    reg_count = 0
     if CONF_OFFSET in config:
         byte_offset = config[CONF_OFFSET]
     # A CONF_BYTE_OFFSET setting overrides CONF_OFFSET
     if CONF_BYTE_OFFSET in config:
         byte_offset = config[CONF_BYTE_OFFSET]
-    if CONF_REGISTER_COUNT in config:
-        reg_count = config[CONF_REGISTER_COUNT]
-    if CONF_VALUE_TYPE in config:
-        value_type = config[CONF_VALUE_TYPE]
-        if reg_count == 0:
-            reg_count = TYPE_REGISTER_MAP[value_type]
     if CONF_CUSTOM_PDU in config:
         if CONF_ADDRESS not in config:
             # generate a unique modbus address using the hash of the name
@@ -317,8 +393,7 @@ def modbus_calc_properties(config: ConfigType) -> tuple[int, int]:
                 value = value.encode()
             config[CONF_ADDRESS] = binascii.crc_hqx(value, 0)
         config[CONF_REGISTER_TYPE] = cv.enum(MODBUS_REGISTER_TYPE)("custom")
-        config[CONF_FORCE_NEW_RANGE] = True
-    return byte_offset, reg_count
+    return byte_offset
 
 
 async def add_modbus_base_properties(

esphome/components/modbus_controller/binary_sensor/__init__.py

@@ -5,6 +5,7 @@ import esphome.config_validation as cv
 from esphome.const import CONF_ADDRESS, CONF_ID
 
 from .. import (
+    RANGE_REUSE,
     ModbusItemBaseSchema,
     SensorItem,
     add_modbus_base_properties,
@@ -12,12 +13,13 @@ from .. import (
     modbus_controller_ns,
     validate_custom_pdu_item,
     validate_modbus_register,
+    validate_range_reuse_migration,
 )
 from ..const import (
     CONF_BITMASK,
-    CONF_FORCE_NEW_RANGE,
     CONF_MODBUS_CONTROLLER_ID,
     CONF_REGISTER_TYPE,
+    CONF_REUSE_PREVIOUS_RANGE,
 )
 
 DEPENDENCIES = ["modbus_controller"]
@@ -38,20 +40,21 @@ CONFIG_SCHEMA = cv.All(
         }
     ),
     validate_modbus_register,
+    validate_range_reuse_migration,
 )
 
 FINAL_VALIDATE_SCHEMA = validate_custom_pdu_item
 
 
 async def to_code(config):
-    byte_offset, _ = modbus_calc_properties(config)
+    byte_offset = modbus_calc_properties(config)
     var = cg.new_Pvariable(
         config[CONF_ID],
         config[CONF_REGISTER_TYPE],
         config[CONF_ADDRESS],
         byte_offset,
         config[CONF_BITMASK],
-        config[CONF_FORCE_NEW_RANGE],
+        RANGE_REUSE[config[CONF_REUSE_PREVIOUS_RANGE]],
     )
     await cg.register_component(var, config)
     await binary_sensor.register_binary_sensor(var, config)

esphome/components/modbus_controller/binary_sensor/modbus_binarysensor.h

@@ -11,19 +11,22 @@ namespace esphome::modbus_controller {
 class ModbusBinarySensor final : public Component, public binary_sensor::BinarySensor, public SensorItem {
  public:
   ModbusBinarySensor(modbus::EntityType register_type, uint16_t start_address, uint8_t offset, uint32_t bitmask,
-                     bool force_new_range) {
+                     RangeReuse reuse_previous_range) {
     this->register_type = register_type;
     this->set_address(start_address);
     this->set_offset_from_start_address(offset);
     this->bitmask = bitmask;
     this->sensor_value_type = SensorValueType::BIT;
-    this->force_new_range = force_new_range;
+    this->reuse_previous_range = reuse_previous_range;
+  }
 
-    if (modbus::helpers::is_entity_type_binary(register_type)) {
-      this->register_count = offset + 1;
-    } else {
-      this->register_count = 1;
+  /// On the bit-addressed tables the bit sits at start_address + offset, so the read must span offset + 1
+  /// bits. Uses the offset as configured: `offset` itself is overwritten with the position in the range.
+  uint16_t entity_count() const override {
+    if (modbus::helpers::is_entity_type_binary(this->register_type)) {
+      return this->offset_from_start_address + 1;
     }
+    return 1;
   }
 
   void parse_and_publish(std::span<const uint8_t> data) override;

esphome/components/modbus_controller/const.py

@@ -18,6 +18,7 @@ CONF_REGISTER_LAST_ADDRESS = "register_last_address"
 CONF_REGISTER_TYPE = "register_type"
 CONF_REGISTER_VALUE = "register_value"
 CONF_RESPONSE_SIZE = "response_size"
+CONF_REUSE_PREVIOUS_RANGE = "reuse_previous_range"
 CONF_SERVER_COURTESY_RESPONSE = "server_courtesy_response"
 CONF_SERVER_REGISTERS = "server_registers"
 CONF_SKIP_UPDATES = "skip_updates"

esphome/components/modbus_controller/modbus_controller.cpp

@@ -3,6 +3,7 @@
 #include "esphome/core/log.h"
 
 #include <cstring>
+#include <limits>
 
 namespace esphome::modbus_controller {
 
@@ -137,7 +138,7 @@ ModbusCommandItem::ModbusCommandItem(ModbusController &controller, modbus::Modbu
                                      SensorItem *sensor)
     : modbus::ModbusClientDevice(parent, address),
       start_address_(sensor->start_address),
-      register_count_(sensor->register_count),
+      register_count_(sensor->entity_count()),
       custom_pdu_(&sensor->custom_pdu),
       controller_(&controller) {
   // The PDU's first byte is its real function code; carry it so dump_config, the on_command_sent
@@ -350,129 +351,176 @@ void ModbusController::update() {
 }
 
 // walk through the sensors and determine the register ranges to read
+namespace {
+
+class RangeBuilder {
+ public:
+  explicit RangeBuilder(FixedVector<RegisterRange> &ranges) : ranges_(ranges) {}
+
+  bool can_join(const SensorItem *curr) const {
+    return this->have_range_ && curr->reuse_previous_range != RangeReuse::NEVER &&
+           this->r_.register_type == curr->register_type && curr->register_type != modbus::EntityType::CUSTOM;
+  }
+
+  // A sensor that joined mid-range must never anchor this - hence both address tests.
+  bool try_reuse_register(SensorItem *curr) {
+    const uint32_t range_end = this->range_end_();
+    if (curr->start_address != range_end - this->prev_->entity_count() ||
+        this->prev_->start_address + this->prev_->entity_count() != range_end ||
+        curr->entity_count() != this->prev_->entity_count() ||
+        curr->get_register_size() != this->prev_->get_register_size()) {
+      return false;
+    }
+    if (!place_offset(curr, static_cast<uint32_t>(this->prev_->offset) + curr->offset_from_start_address))
+      return false;
+    ESP_LOGV(TAG, "Re-use previous register 0x%X", curr->start_address);
+    return true;
+  }
+
+  bool try_extend(SensorItem *curr) {
+    const uint32_t range_end = this->range_end_();
+    const bool reachable =
+        curr->reuse_previous_range == RangeReuse::ALWAYS
+            ? curr->start_address >= range_end
+            : curr->start_address == range_end && (curr->addresses_bits() || !this->range_custom_size_);
+    if (!reachable)
+      return false;
+    const uint16_t gap = static_cast<uint16_t>(curr->start_address - range_end);
+    const uint32_t new_count = this->r_.register_count + gap + curr->entity_count();
+    const uint16_t max_quantity =
+        curr->addresses_bits() ? modbus::MAX_NUM_OF_COILS_TO_READ : modbus::MAX_NUM_OF_REGISTERS_TO_READ;
+    const uint32_t prospective_offset =
+        (curr->addresses_bits() ? static_cast<uint32_t>(curr->start_address - this->r_.start_address)
+                                : static_cast<uint32_t>(this->range_bytes_) + gap * 2) +
+        curr->offset_from_start_address;
+    if (new_count > max_quantity || !place_offset(curr, prospective_offset)) {
+      return false;
+    }
+    if (!curr->addresses_bits())
+      this->range_bytes_ += static_cast<size_t>(gap) * 2;
+    this->range_bytes_ += curr->get_register_size();
+    this->range_custom_size_ = this->range_custom_size_ || has_custom_size(curr);
+    this->r_.register_count = static_cast<uint16_t>(new_count);
+    ESP_LOGV(TAG, "Extend range to include 0x%X", curr->start_address);
+    return true;
+  }
+
+  bool try_cover(SensorItem *curr) {
+    if (!this->range_shared_ || this->range_forced_ || curr->start_address < this->r_.start_address ||
+        curr->start_address + curr->entity_count() > this->range_end_() || this->range_custom_size_ ||
+        has_custom_size(curr)) {
+      return false;
+    }
+    const uint32_t addr_delta = curr->start_address - this->r_.start_address;
+    if (!place_offset(curr, (curr->addresses_bits() ? addr_delta : addr_delta * 2) + curr->offset_from_start_address))
+      return false;
+    ESP_LOGV(TAG, "Register 0x%X already covered by range 0x%X", curr->start_address, this->r_.start_address);
+    return true;
+  }
+
+  // A response dispatches to a single range per (start address, register type), so same-address items
+  // must share - even reuse_previous_range: false and custom entities.
+  bool try_share(SensorItem *curr) {
+    if (!this->have_range_ || this->r_.register_type != curr->register_type ||
+        this->r_.start_address != curr->start_address) {
+      return false;
+    }
+    curr->offset = curr->offset_from_start_address;
+    this->r_.register_count = std::max(this->r_.register_count, curr->entity_count());
+    this->range_bytes_ = std::max(this->range_bytes_, curr->get_register_size());
+    this->range_custom_size_ = this->range_custom_size_ || has_custom_size(curr);
+    this->range_shared_ = true;
+    this->range_forced_ = this->range_forced_ || curr->reuse_previous_range == RangeReuse::NEVER;
+    ESP_LOGV(TAG, "Share range start 0x%X", curr->start_address);
+    return true;
+  }
+
+  bool always_declined(const SensorItem *curr) const {
+    return this->have_range_ && curr->reuse_previous_range == RangeReuse::ALWAYS &&
+           this->r_.register_type == curr->register_type && curr->start_address != this->r_.start_address;
+  }
+
+  void open(SensorItem *curr) {
+    this->close();
+    this->r_ = {};
+    this->range_bytes_ = curr->get_register_size();
+    this->range_custom_size_ = has_custom_size(curr);
+    this->range_forced_ = curr->reuse_previous_range == RangeReuse::NEVER;
+    this->range_shared_ = false;
+    curr->offset = curr->offset_from_start_address;
+    this->r_.start_address = curr->start_address;
+    this->r_.register_count = curr->entity_count();
+    this->r_.register_type = curr->register_type;
+    if (curr->register_type == modbus::EntityType::CUSTOM)
+      this->r_.custom_pdu = &curr->custom_pdu;
+    this->have_range_ = true;
+  }
+
+  void record(SensorItem *curr) {
+    curr->range_start_address = this->r_.start_address;
+    this->r_.sensors.insert(curr);
+    this->prev_ = curr;
+  }
+
+  void close() {
+    if (!this->have_range_)
+      return;
+    ESP_LOGV(TAG, "Add range 0x%X %d", this->r_.start_address, this->r_.register_count);
+    this->ranges_.push_back(std::move(this->r_));
+    this->have_range_ = false;
+  }
+
+ private:
+  uint32_t range_end_() const { return this->r_.start_address + this->r_.register_count; }
+  // The resolved offset must fit its uint8_t field or the sensor would parse the wrong slice.
+  static bool place_offset(SensorItem *curr, uint32_t offset) {
+    if (offset > std::numeric_limits<uint8_t>::max())
+      return false;
+    curr->offset = static_cast<uint8_t>(offset);
+    return true;
+  }
+  static bool has_custom_size(const SensorItem *item) {
+    return item->get_register_size() != static_cast<size_t>(item->entity_count()) * 2;
+  }
+  FixedVector<RegisterRange> &ranges_;
+  RegisterRange r_ = {};
+  bool have_range_ = false;
+  bool range_forced_ = false;  // a reuse: false member blocks the coverage join
+  bool range_shared_ = false;  // only a share-widened range absorbs by coverage
+  size_t range_bytes_ = 0;
+  bool range_custom_size_ = false;
+  SensorItem *prev_ = nullptr;
+};
+
+}  // namespace
+
 void ModbusController::create_polling_commands_() {
   if (this->sensorset_.empty()) {
     ESP_LOGW(TAG, "No sensors registered");
     return;
   }
 
-  // Sensors are walked in the sensor set's order (see SensorItemsComparator): register type, then
-  // force_new_range ahead of the rest, then address - so the walk is not purely address-ordered.
-  // Each keeps the address it was configured with; what is resolved here is its `offset`, the position
-  // of its data within the response of whichever range it ends up in.
-  // One range per sensor is a strict upper bound: each walk step closes at most one range, plus one
-  // closed after the walk. Sized to that bound so no push is ever silently dropped, then handed on by move.
+  // At most one range closes per sensor plus one final close, so sensorset_.size() bounds the pushes
+  // (FixedVector silently drops past capacity).
   FixedVector<RegisterRange> ranges;
   ranges.init(this->sensorset_.size());
-  RegisterRange r = {};
-  bool have_range = false;
-  // Set while the open range belongs to a force_new_range sensor: a range the user asked to keep
-  // separate must not quietly absorb other sensors.
-  bool range_forced = false;
-  // Set once a sensor has joined by sharing the range's start address, which widens the read. Only a
-  // widened range can absorb a later sensor by coverage: ranges that were kept apart before stay apart,
-  // so their frames and polling rates are untouched.
-  bool range_shared = false;
-  // Bytes the range's registers have consumed so far. An extending sensor starts after them, so a
-  // register that returns more bytes than its count implies pushes the sensors after it along.
-  // range_custom_size records whether any of them returns something other than two bytes per register,
-  // which is what makes a position inside the range impossible to work out from addresses alone. Coils
-  // count as such: they carry one bit per address, so bit ranges never take the coverage join.
-  size_t range_bytes = 0;
-  bool range_custom_size = false;
-  SensorItem *prev = nullptr;
+  RangeBuilder builder(ranges);
   for (SensorItem *curr : this->sensorset_) {
-    ESP_LOGV(TAG, "Register: 0x%X count=%d size=%zu offset=%u addr=%p", curr->start_address, curr->register_count,
+    ESP_LOGV(TAG, "Register: 0x%X width=%u size=%zu offset=%u addr=%p", curr->start_address, curr->entity_count(),
              curr->get_register_size(), curr->offset, curr);
-
-    const bool custom_size = curr->get_register_size() != static_cast<size_t>(curr->register_count) * 2;
-
-    bool join = false;
-    if (have_range && !curr->force_new_range && r.register_type == curr->register_type &&
-        curr->register_type != modbus::EntityType::CUSTOM) {
-      if (curr->start_address == (r.start_address + r.register_count - prev->register_count) &&
-          prev->start_address + prev->register_count == r.start_address + r.register_count &&
-          curr->register_count == prev->register_count && curr->get_register_size() == prev->get_register_size()) {
-        // A second sensor on the register(s) the previous one covers: it reads those same bytes,
-        // starting where that sensor's offset pointed, so a chain configured 0/2/4 resolves to 0/2/6.
-        // Both address tests matter. The first identifies the previous sensor's register by working back
-        // from the range's end, which only describes it while it actually sits there - hence the second.
-        // A sensor that joined mid-range must never anchor this, or the next one inherits its offset.
-        curr->offset = static_cast<uint8_t>(prev->offset + curr->offset_from_start_address);
-        join = true;
-        ESP_LOGV(TAG, "Re-use previous register 0x%X", curr->start_address);
-      } else if (curr->start_address == (r.start_address + r.register_count)) {
-        // The next contiguous register(s): the data begins after what the range has consumed so far -
-        // the byte cursor for registers, the distance in bits for coils.
-        curr->offset =
-            static_cast<uint8_t>((curr->addresses_bits() ? curr->start_address - r.start_address : range_bytes) +
-                                 curr->offset_from_start_address);
-        range_bytes += curr->get_register_size();
-        range_custom_size = range_custom_size || custom_size;
-        r.register_count += curr->register_count;
-        join = true;
-        ESP_LOGV(TAG, "Extend range to include 0x%X", curr->start_address);
-      } else if (range_shared && !range_forced && curr->start_address >= r.start_address &&
-                 curr->start_address + curr->register_count <= r.start_address + r.register_count &&
-                 !range_custom_size && !custom_size) {
-        // The registers already fall inside a range that a shared-address join widened, so this sensor
-        // reads its slice of that response instead of adding an overlapping second poll. The guards keep
-        // it narrow: only a widened range, never a force-isolated one; only where every register in the
-        // range returns two bytes, so interior positions follow from the addresses; only sensors genuinely
-        // inside it, which is why the lower bound is needed given the walk is not address-ordered.
-        const uint16_t addr_delta = curr->start_address - r.start_address;
-        curr->offset = static_cast<uint8_t>((curr->addresses_bits() ? addr_delta : addr_delta * 2) +
-                                            curr->offset_from_start_address);
-        join = true;
-        ESP_LOGV(TAG, "Register 0x%X already covered by range 0x%X", curr->start_address, r.start_address);
-      }
+    bool join = builder.can_join(curr) &&
+                (builder.try_reuse_register(curr) || builder.try_extend(curr) || builder.try_cover(curr));
+    if (!join && builder.always_declined(curr)) {
+      ESP_LOGW(TAG, "reuse_previous_range on 0x%X cannot join the previous range; starting a new range",
+               curr->start_address);
     }
-
-    // Sensors on the same start address have to share one range: a response is dispatched to a single
-    // range per (start_address, register_type), so a second range with that key would never receive
-    // data. This holds for force_new_range and custom entities too. The read widens to cover whichever
-    // sensor needs the most registers, which also fixes a short read for coils that use offset.
-    if (!join && have_range && r.register_type == curr->register_type && r.start_address == curr->start_address) {
-      curr->offset = curr->offset_from_start_address;  // shares the range start
-      r.register_count = std::max(r.register_count, curr->register_count);
-      range_bytes = std::max(range_bytes, curr->get_register_size());
-      range_custom_size = range_custom_size || custom_size;
-      range_shared = true;
-      range_forced = range_forced || curr->force_new_range;
-      join = true;
-      ESP_LOGV(TAG, "Share range start 0x%X", curr->start_address);
-    }
-
-    if (!join) {
-      if (have_range) {
-        ESP_LOGV(TAG, "Add range 0x%X %d", r.start_address, r.register_count);
-        ranges.push_back(std::move(r));
-      }
-      r = {};
-      range_bytes = curr->get_register_size();
-      range_custom_size = custom_size;
-      range_forced = curr->force_new_range;
-      range_shared = false;
-      curr->offset = curr->offset_from_start_address;
-      r.start_address = curr->start_address;
-      r.register_count = curr->register_count;
-      r.register_type = curr->register_type;
-      if (curr->register_type == modbus::EntityType::CUSTOM)
-        r.custom_pdu = &curr->custom_pdu;
-      have_range = true;
-    }
-
-    // Every member records its range's first register. The resolved offset is relative to it, so the
-    // two together give the sensor's real position, and the address a write entity targets.
-    curr->range_start_address = r.start_address;
-    r.sensors.insert(curr);
-    prev = curr;
+    join = join || builder.try_share(curr);
+    if (!join)
+      builder.open(curr);
+    builder.record(curr);
   }
-  if (have_range) {
-    ESP_LOGV(TAG, "Add last range 0x%X %d", r.start_address, r.register_count);
-    ranges.push_back(std::move(r));
-  }
-  // Staged in a setup-time vector so the device storage can be sized exactly (see polling_devices_).
+  builder.close();
+
   this->polling_devices_.init(ranges.size());
   for (auto &range : ranges) {
     this->polling_devices_.emplace_back(*this, std::move(range));
@@ -490,8 +538,8 @@ void ModbusController::dump_config() {
 #if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE
   ESP_LOGCONFIG(TAG, "sensormap");
   for (auto &it : this->sensorset_) {
-    ESP_LOGCONFIG(TAG, " Sensor type=%u start=0x%X offset=0x%X count=%d size=%zu",
-                  static_cast<uint8_t>(it->register_type), it->start_address, it->offset, it->register_count,
+    ESP_LOGCONFIG(TAG, " Sensor type=%u start=0x%X offset=0x%X width=%u size=%zu",
+                  static_cast<uint8_t>(it->register_type), it->start_address, it->offset, it->entity_count(),
                   it->get_register_size());
   }
   ESP_LOGCONFIG(TAG, "ranges");

esphome/components/modbus_controller/modbus_controller.h

@@ -126,6 +126,16 @@ inline std::vector<uint16_t> float_to_payload(float value, SensorValueType value
 
 class ModbusController;
 
+/// How an item relates to the register range built just before it (same register type, address order).
+/// The numeric order doubles as the comparator tiebreak for items at the same address (see
+/// SensorItemsComparator): AUTO items form the shared range first, so a NEVER item comes last and
+/// shares a range it did not start (items on one address must share, see create_polling_commands_()).
+enum class RangeReuse : uint8_t {
+  AUTO = 0,    // join when adjacent and the position in the reply is exact (no non-standard response_size ahead)
+  ALWAYS = 1,  // join unconditionally, reading across any address gap
+  NEVER = 2,   // never join backward (later items may still extend this item's range)
+};
+
 class SensorItem {
  public:
   /// Parse this sensor's slice out of its range's response and publish it. The span points into the
@@ -159,11 +169,26 @@ class SensorItem {
   }
 
   void set_custom_pdu(std::initializer_list<uint8_t> pdu) { this->custom_pdu.set(pdu.begin(), pdu.size()); }
+
+  /// Entities this item spans: one bit for bit-addressed types, ceil(bytes / 2) registers for RAW
+  /// with a response_size, else the value type's register width.
+  virtual uint16_t entity_count() const {
+    if (modbus::helpers::is_entity_type_binary(this->register_type)) {
+      return 1;
+    }
+    if (this->sensor_value_type == SensorValueType::RAW && this->response_bytes > 0) {
+      return (this->response_bytes + 1) / 2;
+    }
+    return modbus::helpers::register_width_for(this->sensor_value_type);
+  }
+
+  /// Bytes this item's registers occupy in a response: one per bit for bit-addressed types; response_size
+  /// when set (devices that answer more bytes per register than the standard two); else two per register.
   size_t virtual get_register_size() const {
     if (this->addresses_bits()) {
       return 1;
     } else {  // if CONF_RESPONSE_BYTES is used override the default
-      return response_bytes > 0 ? response_bytes : register_count * 2;
+      return response_bytes > 0 ? response_bytes : this->entity_count() * 2;
     }
   }
   // Override register size for modbus devices not using 1 register for one dword
@@ -177,7 +202,6 @@ class SensorItem {
   /// for the registers ahead of it (including wide response_size ones) and for any offset inherited
   /// from an earlier sensor sharing the same register.
   uint8_t offset{0};
-  uint8_t register_count{0};
   uint8_t response_bytes{0};
   /// The offset exactly as configured: measured from this sensor's own start_address, where `offset`
   /// is measured from the first register of the range it ends up polled in. Same units as `offset` -
@@ -188,7 +212,7 @@ class SensorItem {
   /// First register of the range this sensor is polled in; equals start_address for an unpolled item.
   uint16_t range_start_address{0};
   SmallInlineBuffer<8> custom_pdu{};
-  bool force_new_range{false};
+  RangeReuse reuse_previous_range{RangeReuse::AUTO};
 };
 
 // ModbusController::create_polling_commands_ tries to optimize register range
@@ -201,16 +225,17 @@ class SensorItemsComparator {
       return lhs->register_type < rhs->register_type;
     }
 
-    // ensure that sensor with force_new_range set are before the others
-    if (lhs->force_new_range != rhs->force_new_range) {
-      return lhs->force_new_range > rhs->force_new_range;
-    }
-
     // sort by start address
     if (lhs->start_address != rhs->start_address) {
       return lhs->start_address < rhs->start_address;
     }
 
+    // at the same address: AUTO before ALWAYS before NEVER, so a NEVER item never starts the range
+    // the others at that address are then forced to share (see RangeReuse)
+    if (lhs->reuse_previous_range != rhs->reuse_previous_range) {
+      return lhs->reuse_previous_range < rhs->reuse_previous_range;
+    }
+
     // sort by the offset as configured (ensures update of sensors in ascending order). The resolved
     // `offset` is deliberately not used: ranges are built while iterating this set and assign it, and
     // a sort key that changed under the iteration would corrupt the set's ordering.
@@ -229,8 +254,8 @@ using SensorSet = std::set<SensorItem *, SensorItemsComparator>;
 struct RegisterRange {
   uint16_t start_address;
   modbus::EntityType register_type;
-  uint8_t register_count;
-  SensorSet sensors;  // all sensors of this range
+  uint16_t register_count;  // registers (or bits) the poll command reads; joins across gaps can exceed 255
+  SensorSet sensors;        // all sensors of this range
   /// A custom range polls this PDU, referenced from the sensor that opened the range.
   const SmallInlineBuffer<8> *custom_pdu{nullptr};
 };

esphome/components/modbus_controller/number/__init__.py

@@ -17,20 +17,22 @@ from esphome.const import (
 from esphome.types import ConfigType
 
 from .. import (
+    RANGE_REUSE,
     ModbusItemBaseSchema,
     SensorItem,
     add_modbus_base_properties,
     modbus_calc_properties,
     modbus_controller_ns,
     validate_custom_pdu_item,
+    validate_range_reuse_migration,
 )
 from ..const import (
     CONF_BITMASK,
     CONF_CUSTOM_COMMAND,
     CONF_CUSTOM_PDU,
-    CONF_FORCE_NEW_RANGE,
     CONF_MODBUS_CONTROLLER_ID,
     CONF_REGISTER_TYPE,
+    CONF_REUSE_PREVIOUS_RANGE,
     CONF_USE_WRITE_MULTIPLE,
     CONF_VALUE_TYPE,
     CONF_WRITE_LAMBDA,
@@ -86,13 +88,14 @@ CONFIG_SCHEMA = cv.All(
     ),
     validate_min_max,
     validate_modbus_number,
+    validate_range_reuse_migration,
 )
 
 FINAL_VALIDATE_SCHEMA = validate_custom_pdu_item
 
 
 async def to_code(config: ConfigType) -> None:
-    byte_offset, reg_count = modbus_calc_properties(config)
+    byte_offset = modbus_calc_properties(config)
     var = cg.new_Pvariable(
         config[CONF_ID],
         config[CONF_REGISTER_TYPE],
@@ -100,8 +103,7 @@ async def to_code(config: ConfigType) -> None:
         byte_offset,
         config[CONF_BITMASK],
         config[CONF_VALUE_TYPE],
-        reg_count,
-        config[CONF_FORCE_NEW_RANGE],
+        RANGE_REUSE[config[CONF_REUSE_PREVIOUS_RANGE]],
     )
 
     await cg.register_component(var, config)

esphome/components/modbus_controller/number/modbus_number.cpp

@@ -83,10 +83,10 @@ void ModbusNumber::control(float value) {
 
   ESP_LOGD(TAG,
            "Updating register: connected Sensor=%s start address=0x%X register count=%d new value=%.02f (val=%.02f)",
-           this->get_name().c_str(), this->start_address, this->register_count, value, write_value);
+           this->get_name().c_str(), this->start_address, this->entity_count(), value, write_value);
 
   bool queued;
-  if (this->register_count == 1 && !this->use_write_multiple_) {
+  if (this->entity_count() == 1 && !this->use_write_multiple_) {
     queued = this->write_single_register(this->write_address(), data[0]);
   } else {
     queued = this->write_multiple_registers(this->write_address(), data);

esphome/components/modbus_controller/number/modbus_number.h

@@ -13,14 +13,13 @@ using value_to_data_t = std::function<float>(float);
 class ModbusNumber final : public number::Number, public Component, public SensorItem, public WriterEntity {
  public:
   ModbusNumber(modbus::EntityType register_type, uint16_t start_address, uint8_t offset, uint32_t bitmask,
-               SensorValueType value_type, int register_count, bool force_new_range) {
+               SensorValueType value_type, RangeReuse reuse_previous_range) {
     this->register_type = register_type;
     this->set_address(start_address);
     this->set_offset_from_start_address(offset);
     this->bitmask = bitmask;
     this->sensor_value_type = value_type;
-    this->register_count = register_count;
-    this->force_new_range = force_new_range;
+    this->reuse_previous_range = reuse_previous_range;
   };
 
   void dump_config() override;

esphome/components/modbus_controller/output/__init__.py

@@ -1,3 +1,5 @@
+import logging
+
 import esphome.codegen as cg
 from esphome.components import output
 from esphome.components.modbus.helpers import (
@@ -12,6 +14,7 @@ from esphome.types import ConfigType
 from .. import (
     ModbusItemBaseSchema,
     SensorItem,
+    entity_label,
     modbus_calc_properties,
     modbus_controller_ns,
     reject_odd_holding_write_offset,
@@ -19,13 +22,18 @@ from .. import (
 from ..const import (
     CONF_CUSTOM_COMMAND,
     CONF_CUSTOM_PDU,
+    CONF_FORCE_NEW_RANGE,
     CONF_MODBUS_CONTROLLER_ID,
+    CONF_REGISTER_COUNT,
     CONF_REGISTER_TYPE,
+    CONF_REUSE_PREVIOUS_RANGE,
     CONF_USE_WRITE_MULTIPLE,
     CONF_VALUE_TYPE,
     CONF_WRITE_LAMBDA,
 )
 
+_LOGGER = logging.getLogger(__name__)
+
 DEPENDENCIES = ["modbus_controller"]
 CODEOWNERS = ["@martgras"]
 
@@ -38,26 +46,30 @@ ModbusBinaryOutput = modbus_controller_ns.class_(
 )
 
 
-CONFIG_SCHEMA = cv.typed_schema(
-    {
-        "coil": output.BINARY_OUTPUT_SCHEMA.extend(ModbusItemBaseSchema).extend(
-            {
-                cv.GenerateID(): cv.declare_id(ModbusBinaryOutput),
-                cv.Required(CONF_ADDRESS): cv.positive_int,
-                cv.Optional(CONF_CUSTOM_PDU): cv.invalid(
-                    "custom_pdu is not supported for outputs; use a write_lambda instead"
-                ),
-                cv.Optional(CONF_CUSTOM_COMMAND): cv.invalid(
-                    "custom_command is not supported for outputs; use a write_lambda instead"
-                ),
-                cv.Optional(CONF_WRITE_LAMBDA): cv.returning_lambda,
-                cv.Optional(CONF_USE_WRITE_MULTIPLE, default=False): cv.boolean,
-            }
-        ),
-        "holding": cv.All(
-            output.FLOAT_OUTPUT_SCHEMA.extend(ModbusItemBaseSchema).extend(
+def _warn_unused_range_options(config: ConfigType) -> ConfigType:
+    # Outputs are write-only and never polled, so nothing here builds a range for them. The write
+    # spans whatever the payload holds, so register_count no longer bounds it either.
+    for key in (CONF_FORCE_NEW_RANGE, CONF_REGISTER_COUNT):
+        if config.pop(key, None) is not None:
+            _LOGGER.warning(
+                "%s: '%s' has no effect on outputs; remove it. Removed in 2027.3.0",
+                entity_label(config),
+                key,
+            )
+    if config.pop(CONF_REUSE_PREVIOUS_RANGE, None) not in (None, "auto"):
+        raise cv.Invalid(
+            f"'{CONF_REUSE_PREVIOUS_RANGE}' has no effect on outputs: they are write-only and are "
+            f"never part of a polled range. Remove it."
+        )
+    return config
+
+
+CONFIG_SCHEMA = cv.All(
+    cv.typed_schema(
+        {
+            "coil": output.BINARY_OUTPUT_SCHEMA.extend(ModbusItemBaseSchema).extend(
                 {
-                    cv.GenerateID(): cv.declare_id(ModbusFloatOutput),
+                    cv.GenerateID(): cv.declare_id(ModbusBinaryOutput),
                     cv.Required(CONF_ADDRESS): cv.positive_int,
                     cv.Optional(CONF_CUSTOM_PDU): cv.invalid(
                         "custom_pdu is not supported for outputs; use a write_lambda instead"
@@ -65,25 +77,42 @@ CONFIG_SCHEMA = cv.typed_schema(
                     cv.Optional(CONF_CUSTOM_COMMAND): cv.invalid(
                         "custom_command is not supported for outputs; use a write_lambda instead"
                     ),
-                    cv.Optional(CONF_VALUE_TYPE, default="U_WORD"): cv.enum(
-                        SENSOR_VALUE_TYPE
-                    ),
                     cv.Optional(CONF_WRITE_LAMBDA): cv.returning_lambda,
-                    cv.Optional(CONF_MULTIPLY, default=1.0): cv.float_,
                     cv.Optional(CONF_USE_WRITE_MULTIPLE, default=False): cv.boolean,
                 }
             ),
-            reject_odd_holding_write_offset,
-        ),
-    },
-    lower=True,
-    key=CONF_REGISTER_TYPE,
-    default_type="holding",
+            "holding": cv.All(
+                output.FLOAT_OUTPUT_SCHEMA.extend(ModbusItemBaseSchema).extend(
+                    {
+                        cv.GenerateID(): cv.declare_id(ModbusFloatOutput),
+                        cv.Required(CONF_ADDRESS): cv.positive_int,
+                        cv.Optional(CONF_CUSTOM_PDU): cv.invalid(
+                            "custom_pdu is not supported for outputs; use a write_lambda instead"
+                        ),
+                        cv.Optional(CONF_CUSTOM_COMMAND): cv.invalid(
+                            "custom_command is not supported for outputs; use a write_lambda instead"
+                        ),
+                        cv.Optional(CONF_VALUE_TYPE, default="U_WORD"): cv.enum(
+                            SENSOR_VALUE_TYPE
+                        ),
+                        cv.Optional(CONF_WRITE_LAMBDA): cv.returning_lambda,
+                        cv.Optional(CONF_MULTIPLY, default=1.0): cv.float_,
+                        cv.Optional(CONF_USE_WRITE_MULTIPLE, default=False): cv.boolean,
+                    }
+                ),
+                reject_odd_holding_write_offset,
+            ),
+        },
+        lower=True,
+        key=CONF_REGISTER_TYPE,
+        default_type="holding",
+    ),
+    _warn_unused_range_options,
 )
 
 
 async def to_code(config: ConfigType) -> None:
-    byte_offset, reg_count = modbus_calc_properties(config)
+    byte_offset = modbus_calc_properties(config)
     # Binary Output
     write_template = None
     if config[CONF_REGISTER_TYPE] == "coil":
@@ -109,7 +138,6 @@ async def to_code(config: ConfigType) -> None:
             config[CONF_ADDRESS],
             byte_offset,
             config[CONF_VALUE_TYPE],
-            reg_count,
         )
         cg.add(var.set_write_multiply(config[CONF_MULTIPLY]))
         if CONF_WRITE_LAMBDA in config:

esphome/components/modbus_controller/output/modbus_output.cpp

@@ -46,29 +46,24 @@ void ModbusFloatOutput::write_state(float value) {
     modbus::helpers::float_to_payload(data, value, this->sensor_value_type);
   }
 
-  ESP_LOGD(TAG, "Updating register: start address=0x%X register count=%d new value=%.02f (val=%.02f)",
-           this->start_address, this->register_count, value, original_value);
+  ESP_LOGD(TAG, "Updating register: start address=0x%X register count=%u new value=%.02f (val=%.02f)",
+           this->start_address, this->entity_count(), value, original_value);
 
-  // The command declares register_count registers, so the payload must be exactly that many words;
-  // anything else would put a byte count on the wire that disagrees with the quantity field.
-  // number_to_payload() appends nothing for RAW, so an empty payload must be caught before data[0].
+  // float_to_payload() appends nothing for RAW, so an empty payload must be caught before data[0].
   if (data.empty()) {
     ESP_LOGW(TAG, "No payload was created for updating output");
     return;
   }
 
-  // register_count declares the READ range width - it may pull neighboring registers into one poll -
-  // so a write covers exactly the registers the value occupies: the quantity comes from the payload,
-  // never from register_count (padding to it would zero registers the user only declared for reading).
-  // A payload wider than the declared range means the config and the lambda disagree - drop it.
-  if (data.size() > this->register_count) {
-    ESP_LOGE(TAG, "Payload has %zu registers but register_count is %u; dropping write", data.size(),
-             this->register_count);
+  // The value type sets the write width, so a wider payload means the config and the lambda disagree.
+  if (data.size() > this->entity_count()) {
+    ESP_LOGE(TAG, "Payload has %zu registers but the value type only spans %u; dropping write", data.size(),
+             this->entity_count());
     return;
   }
 
   bool queued;
-  if (this->register_count == 1 && !this->use_write_multiple_) {
+  if (this->entity_count() == 1 && !this->use_write_multiple_) {
     queued = this->write_single_register(this->write_address(), data[0]);
   } else {
     queued = this->write_multiple_registers(this->write_address(), data);
@@ -85,7 +80,7 @@ void ModbusFloatOutput::dump_config() {
                 "  Device start address: 0x%X\n"
                 "  Register count: %d\n"
                 "  Value type: %d",
-                this->start_address, this->register_count, static_cast<int>(this->sensor_value_type));
+                this->start_address, this->entity_count(), static_cast<int>(this->sensor_value_type));
 }
 
 // ModbusBinaryOutput
@@ -145,7 +140,7 @@ void ModbusBinaryOutput::dump_config() {
                 "  Device start address: 0x%X\n"
                 "  Register count: %d\n"
                 "  Value type: %d",
-                this->start_address, this->register_count, static_cast<int>(this->sensor_value_type));
+                this->start_address, this->entity_count(), static_cast<int>(this->sensor_value_type));
 }
 
 }  // namespace esphome::modbus_controller

esphome/components/modbus_controller/output/modbus_output.h

@@ -10,13 +10,12 @@ namespace esphome::modbus_controller {
 
 class ModbusFloatOutput final : public output::FloatOutput, public Component, public SensorItem, public WriterEntity {
  public:
-  ModbusFloatOutput(uint16_t start_address, uint8_t offset, SensorValueType value_type, int register_count) {
+  ModbusFloatOutput(uint16_t start_address, uint8_t offset, SensorValueType value_type) {
     this->register_type = modbus::EntityType::HOLDING;
     // A byte offset folds into the address as whole registers; odd offsets are rejected at validation.
     this->set_address(start_address + offset / 2);
     this->set_offset_from_start_address(0);
     this->bitmask = 0xFFFFFFFF;
-    this->register_count = register_count;
     this->sensor_value_type = value_type;
   }
   void dump_config() override;
@@ -46,7 +45,6 @@ class ModbusBinaryOutput final : public output::BinaryOutput, public Component,
     this->set_address(start_address + offset);
     this->bitmask = 0xFFFFFFFF;
     this->sensor_value_type = SensorValueType::BIT;
-    this->register_count = 1;
     this->set_offset_from_start_address(0);
   }
   void dump_config() override;

esphome/components/modbus_controller/select/__init__.py

@@ -3,25 +3,24 @@ from typing import Any
 
 import esphome.codegen as cg
 from esphome.components import select
-from esphome.components.modbus.helpers import (
-    SENSOR_VALUE_TYPE,
-    TYPE_REGISTER_MAP,
-    RegisterValues,
-)
+from esphome.components.modbus.helpers import SENSOR_VALUE_TYPE, RegisterValues
 import esphome.config_validation as cv
 from esphome.const import CONF_ADDRESS, CONF_ID, CONF_LAMBDA, CONF_OPTIMISTIC
 from esphome.types import ConfigType
 
 from .. import (
+    RANGE_REUSE,
     ModbusController,
     SensorItem,
     modbus_controller_ns,
+    validate_range_reuse_migration,
     validate_skip_updates_deprecated,
 )
 from ..const import (
     CONF_FORCE_NEW_RANGE,
     CONF_MODBUS_CONTROLLER_ID,
     CONF_REGISTER_COUNT,
+    CONF_REUSE_PREVIOUS_RANGE,
     CONF_SKIP_UPDATES,
     CONF_USE_WRITE_MULTIPLE,
     CONF_VALUE_TYPE,
@@ -55,18 +54,6 @@ def ensure_option_map() -> Callable[[Any], dict[str, int]]:
     return validator
 
 
-def register_count_value_type_min(value: ConfigType) -> ConfigType:
-    reg_count = value.get(CONF_REGISTER_COUNT)
-    if reg_count is not None:
-        value_type = value[CONF_VALUE_TYPE]
-        min_register_count = TYPE_REGISTER_MAP[value_type]
-        if min_register_count > reg_count:
-            raise cv.Invalid(
-                f"Value type {value_type} needs at least {min_register_count} registers"
-            )
-    return value
-
-
 INTEGER_SENSOR_VALUE_TYPE = {
     key: value for key, value in SENSOR_VALUE_TYPE.items() if not key.startswith("FP")
 }
@@ -81,9 +68,13 @@ CONFIG_SCHEMA = cv.All(
             cv.Optional(CONF_VALUE_TYPE, default="U_WORD"): cv.enum(
                 INTEGER_SENSOR_VALUE_TYPE
             ),
-            cv.Optional(CONF_REGISTER_COUNT): cv.positive_int,
             cv.Optional(CONF_SKIP_UPDATES): validate_skip_updates_deprecated,
-            cv.Optional(CONF_FORCE_NEW_RANGE, default=False): cv.boolean,
+            cv.Optional(CONF_REUSE_PREVIOUS_RANGE, default="auto"): cv.Any(
+                cv.boolean, cv.one_of("auto", lower=True)
+            ),
+            # Deprecated options, migrated by validate_range_reuse_migration(). Remove before 2027.3.0
+            cv.Optional(CONF_FORCE_NEW_RANGE): cv.boolean,
+            cv.Optional(CONF_REGISTER_COUNT): cv.positive_int,
             cv.Required(CONF_OPTIONSMAP): ensure_option_map(),
             cv.Optional(CONF_USE_WRITE_MULTIPLE, default=False): cv.boolean,
             cv.Optional(CONF_OPTIMISTIC, default=False): cv.boolean,
@@ -91,24 +82,18 @@ CONFIG_SCHEMA = cv.All(
             cv.Optional(CONF_WRITE_LAMBDA): cv.returning_lambda,
         },
     ),
-    register_count_value_type_min,
+    validate_range_reuse_migration,
 )
 
 
 async def to_code(config: ConfigType) -> None:
-    value_type = config[CONF_VALUE_TYPE]
-    reg_count = config.get(CONF_REGISTER_COUNT)
-    if reg_count is None:
-        reg_count = TYPE_REGISTER_MAP[value_type]
-
     options_map = config[CONF_OPTIONSMAP]
 
     var = cg.new_Pvariable(
         config[CONF_ID],
-        value_type,
+        config[CONF_VALUE_TYPE],
         config[CONF_ADDRESS],
-        reg_count,
-        config[CONF_FORCE_NEW_RANGE],
+        RANGE_REUSE[config[CONF_REUSE_PREVIOUS_RANGE]],
         list(options_map.values()),
     )
 

esphome/components/modbus_controller/select/modbus_select.cpp

@@ -83,19 +83,17 @@ void ModbusSelect::control(size_t index) {
     }
   }
 
-  // register_count declares the READ range width - it may pull neighboring registers into one poll -
-  // so a write covers exactly the registers the value occupies: the quantity comes from the payload,
-  // never from register_count (padding to it would zero registers the user only declared for reading).
-  // A payload wider than the declared range means the config and the lambda disagree - drop it.
-  if (data.size() > this->register_count) {
-    ESP_LOGE(TAG, "Payload has %zu registers but register_count is %u; dropping write", data.size(),
-             this->register_count);
+  // A write covers exactly the registers the value occupies: the quantity comes from the payload. A
+  // payload wider than the value type's register width means the config and the lambda disagree - drop it.
+  if (data.size() > this->entity_count()) {
+    ESP_LOGE(TAG, "Payload has %zu registers but the value type only spans %u; dropping write", data.size(),
+             this->entity_count());
     return;
   }
 
   const uint16_t write_address = this->write_address();
   bool queued;
-  if ((this->register_count == 1) && (!this->use_write_multiple_)) {
+  if ((this->entity_count() == 1) && (!this->use_write_multiple_)) {
     queued = this->write_single_register(write_address, data[0]);
   } else {
     queued = this->write_multiple_registers(write_address, data);

esphome/components/modbus_controller/select/modbus_select.h

@@ -11,16 +11,15 @@ namespace esphome::modbus_controller {
 
 class ModbusSelect final : public Component, public select::Select, public SensorItem, public WriterEntity {
  public:
-  ModbusSelect(SensorValueType sensor_value_type, uint16_t start_address, uint8_t register_count, bool force_new_range,
+  ModbusSelect(SensorValueType sensor_value_type, uint16_t start_address, RangeReuse reuse_previous_range,
                std::vector<int64_t> mapping) {
     this->register_type = modbus::EntityType::HOLDING;  // not configurable
     this->sensor_value_type = sensor_value_type;
     this->set_address(start_address);
     this->set_offset_from_start_address(0);  // not configurable
     this->bitmask = 0xFFFFFFFF;              // not configurable
-    this->register_count = register_count;
-    this->response_bytes = 0;  // not configurable
-    this->force_new_range = force_new_range;
+    this->response_bytes = 0;                // not configurable
+    this->reuse_previous_range = reuse_previous_range;
     this->mapping_ = std::move(mapping);
   }
 

esphome/components/modbus_controller/sensor/__init__.py

@@ -5,6 +5,7 @@ import esphome.config_validation as cv
 from esphome.const import CONF_ADDRESS, CONF_ID
 
 from .. import (
+    RANGE_REUSE,
     ModbusItemBaseSchema,
     SensorItem,
     add_modbus_base_properties,
@@ -12,13 +13,13 @@ from .. import (
     modbus_controller_ns,
     validate_custom_pdu_item,
     validate_modbus_register,
+    validate_range_reuse_migration,
 )
 from ..const import (
     CONF_BITMASK,
-    CONF_FORCE_NEW_RANGE,
     CONF_MODBUS_CONTROLLER_ID,
-    CONF_REGISTER_COUNT,
     CONF_REGISTER_TYPE,
+    CONF_REUSE_PREVIOUS_RANGE,
     CONF_VALUE_TYPE,
 )
 
@@ -38,27 +39,25 @@ CONFIG_SCHEMA = cv.All(
         {
             cv.Optional(CONF_REGISTER_TYPE): cv.enum(MODBUS_REGISTER_TYPE),
             cv.Optional(CONF_VALUE_TYPE, default="U_WORD"): cv.enum(SENSOR_VALUE_TYPE),
-            cv.Optional(CONF_REGISTER_COUNT, default=0): cv.positive_int,
         }
     ),
     validate_modbus_register,
+    validate_range_reuse_migration,
 )
 
 FINAL_VALIDATE_SCHEMA = validate_custom_pdu_item
 
 
 async def to_code(config):
-    byte_offset, reg_count = modbus_calc_properties(config)
-    value_type = config[CONF_VALUE_TYPE]
+    byte_offset = modbus_calc_properties(config)
     var = cg.new_Pvariable(
         config[CONF_ID],
         config[CONF_REGISTER_TYPE],
         config[CONF_ADDRESS],
         byte_offset,
         config[CONF_BITMASK],
-        value_type,
-        reg_count,
-        config[CONF_FORCE_NEW_RANGE],
+        config[CONF_VALUE_TYPE],
+        RANGE_REUSE[config[CONF_REUSE_PREVIOUS_RANGE]],
     )
     await cg.register_component(var, config)
     await sensor.register_sensor(var, config)

esphome/components/modbus_controller/sensor/modbus_sensor.h

@@ -11,14 +11,13 @@ namespace esphome::modbus_controller {
 class ModbusSensor final : public Component, public sensor::Sensor, public SensorItem {
  public:
   ModbusSensor(modbus::EntityType register_type, uint16_t start_address, uint8_t offset, uint32_t bitmask,
-               SensorValueType value_type, int register_count, bool force_new_range) {
+               SensorValueType value_type, RangeReuse reuse_previous_range) {
     this->register_type = register_type;
     this->set_address(start_address);
     this->set_offset_from_start_address(offset);
     this->bitmask = bitmask;
     this->sensor_value_type = value_type;
-    this->register_count = register_count;
-    this->force_new_range = force_new_range;
+    this->reuse_previous_range = reuse_previous_range;
   }
 
   void parse_and_publish(std::span<const uint8_t> data) override;

esphome/components/modbus_controller/switch/__init__.py

@@ -6,6 +6,7 @@ from esphome.const import CONF_ADDRESS, CONF_ASSUMED_STATE, CONF_ID
 from esphome.types import ConfigType
 
 from .. import (
+    RANGE_REUSE,
     ModbusItemBaseSchema,
     SensorItem,
     add_modbus_base_properties,
@@ -14,12 +15,13 @@ from .. import (
     reject_odd_holding_write_offset,
     validate_custom_pdu_item,
     validate_modbus_register,
+    validate_range_reuse_migration,
 )
 from ..const import (
     CONF_BITMASK,
-    CONF_FORCE_NEW_RANGE,
     CONF_MODBUS_CONTROLLER_ID,
     CONF_REGISTER_TYPE,
+    CONF_REUSE_PREVIOUS_RANGE,
     CONF_USE_WRITE_MULTIPLE,
     CONF_WRITE_LAMBDA,
 )
@@ -54,20 +56,21 @@ CONFIG_SCHEMA = cv.All(
     ),
     validate_modbus_register,
     _validate_holding_offset,
+    validate_range_reuse_migration,
 )
 
 FINAL_VALIDATE_SCHEMA = validate_custom_pdu_item
 
 
 async def to_code(config: ConfigType) -> None:
-    byte_offset, _ = modbus_calc_properties(config)
+    byte_offset = modbus_calc_properties(config)
     var = cg.new_Pvariable(
         config[CONF_ID],
         config[CONF_REGISTER_TYPE],
         config[CONF_ADDRESS],
         byte_offset,
         config[CONF_BITMASK],
-        config[CONF_FORCE_NEW_RANGE],
+        RANGE_REUSE[config[CONF_REUSE_PREVIOUS_RANGE]],
     )
     await cg.register_component(var, config)
     await switch.register_switch(var, config)

esphome/components/modbus_controller/switch/modbus_switch.h

@@ -11,13 +11,12 @@ namespace esphome::modbus_controller {
 class ModbusSwitch final : public Component, public switch_::Switch, public SensorItem, public WriterEntity {
  public:
   ModbusSwitch(modbus::EntityType register_type, uint16_t start_address, uint8_t offset, uint32_t bitmask,
-               bool force_new_range) {
+               RangeReuse reuse_previous_range) {
     this->register_type = register_type;
     this->set_address(start_address);
     this->set_offset_from_start_address(offset);
     this->bitmask = bitmask;
     this->sensor_value_type = SensorValueType::BIT;
-    this->register_count = 1;
     // A holding byte offset folds into the address as whole registers (odd offsets are rejected at
     // validation: a 16-bit register write cannot target half a register); a coil offset is a coil count.
     if (register_type == modbus::EntityType::HOLDING) {
@@ -27,7 +26,7 @@ class ModbusSwitch final : public Component, public switch_::Switch, public Sens
       this->set_address(start_address + offset);
       this->set_offset_from_start_address(0);
     }
-    this->force_new_range = force_new_range;
+    this->reuse_previous_range = reuse_previous_range;
   };
   void setup() override;
   void write_state(bool state) override;

esphome/components/modbus_controller/text_sensor/__init__.py

@@ -5,6 +5,7 @@ import esphome.config_validation as cv
 from esphome.const import CONF_ADDRESS, CONF_ID
 
 from .. import (
+    RANGE_REUSE,
     ModbusItemBaseSchema,
     SensorItem,
     add_modbus_base_properties,
@@ -12,14 +13,14 @@ from .. import (
     modbus_controller_ns,
     validate_custom_pdu_item,
     validate_modbus_register,
+    validate_range_reuse_migration,
 )
 from ..const import (
-    CONF_FORCE_NEW_RANGE,
     CONF_MODBUS_CONTROLLER_ID,
     CONF_RAW_ENCODE,
-    CONF_REGISTER_COUNT,
     CONF_REGISTER_TYPE,
     CONF_RESPONSE_SIZE,
+    CONF_REUSE_PREVIOUS_RANGE,
 )
 
 DEPENDENCIES = ["modbus_controller"]
@@ -47,32 +48,27 @@ CONFIG_SCHEMA = cv.All(
         {
             cv.GenerateID(): cv.declare_id(ModbusTextSensor),
             cv.Optional(CONF_REGISTER_TYPE): cv.enum(MODBUS_REGISTER_TYPE),
-            cv.Optional(CONF_REGISTER_COUNT, default=0): cv.positive_int,
-            cv.Optional(CONF_RESPONSE_SIZE, default=2): cv.positive_int,
+            cv.Optional(CONF_RESPONSE_SIZE, default=2): cv.int_range(min=1, max=250),
             cv.Optional(CONF_RAW_ENCODE, default="ANSI"): cv.enum(RAW_ENCODING),
         }
     ),
     validate_modbus_register,
+    validate_range_reuse_migration,
 )
 
 FINAL_VALIDATE_SCHEMA = validate_custom_pdu_item
 
 
 async def to_code(config):
-    byte_offset, reg_count = modbus_calc_properties(config)
-    response_size = config[CONF_RESPONSE_SIZE]
-    reg_count = config[CONF_REGISTER_COUNT]
-    if reg_count == 0:
-        reg_count = response_size // 2
+    byte_offset = modbus_calc_properties(config)
     var = cg.new_Pvariable(
         config[CONF_ID],
         config[CONF_REGISTER_TYPE],
         config[CONF_ADDRESS],
         byte_offset,
-        reg_count,
         config[CONF_RESPONSE_SIZE],
         config[CONF_RAW_ENCODE],
-        config[CONF_FORCE_NEW_RANGE],
+        RANGE_REUSE[config[CONF_REUSE_PREVIOUS_RANGE]],
     )
 
     await cg.register_component(var, config)

esphome/components/modbus_controller/text_sensor/modbus_textsensor.h

@@ -12,17 +12,16 @@ enum class RawEncoding { NONE = 0, HEXBYTES = 1, COMMA = 2, ANSI = 3 };
 
 class ModbusTextSensor final : public Component, public text_sensor::TextSensor, public SensorItem {
  public:
-  ModbusTextSensor(modbus::EntityType register_type, uint16_t start_address, uint8_t offset, uint8_t register_count,
-                   uint16_t response_bytes, RawEncoding encode, bool force_new_range) {
+  ModbusTextSensor(modbus::EntityType register_type, uint16_t start_address, uint8_t offset, uint16_t response_bytes,
+                   RawEncoding encode, RangeReuse reuse_previous_range) {
     this->register_type = register_type;
     this->set_address(start_address);
     this->set_offset_from_start_address(offset);
     this->response_bytes = response_bytes;
-    this->register_count = register_count;
     this->encode_ = encode;
     this->bitmask = 0xFFFFFFFF;
     this->sensor_value_type = SensorValueType::RAW;
-    this->force_new_range = force_new_range;
+    this->reuse_previous_range = reuse_previous_range;
   }
 
   void dump_config() override;

esphome/components/pzemac/pzemac.cpp

@@ -3,62 +3,64 @@
 
 namespace esphome::pzemac {
 
+namespace helpers = modbus::helpers;
+
 static const char *const TAG = "pzemac";
 
 static const uint8_t PZEM_CMD_RESET_ENERGY = 0x42;
 static const uint8_t PZEM_REGISTER_COUNT = 10;  // 10x 16-bit registers
 
-void PZEMAC::on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) {
-  auto data = modbus::helpers::server_pdu_payload(response_pdu);
-  if (data.size() < 20) {
-    ESP_LOGW(TAG, "Invalid size for PZEM AC!");
+// Register map, see https://github.com/esphome/feature-requests/issues/49#issuecomment-538636809
+// 32-bit values are two registers, low word first.
+static const uint16_t PZEM_REGISTER_VOLTAGE = 0;        // 1 register, 0.1 V
+static const uint16_t PZEM_REGISTER_CURRENT = 1;        // 2 registers, 0.001 A
+static const uint16_t PZEM_REGISTER_ACTIVE_POWER = 3;   // 2 registers, 0.1 W
+static const uint16_t PZEM_REGISTER_ACTIVE_ENERGY = 5;  // 2 registers, 1 Wh
+static const uint16_t PZEM_REGISTER_FREQUENCY = 7;      // 1 register, 0.1 Hz
+static const uint16_t PZEM_REGISTER_POWER_FACTOR = 8;   // 1 register, 0.01
+
+void PZEMAC::on_read_input_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                                     modbus::ResponseStatus status) {
+  if (!modbus::succeeded(status))
+    return;  // the hub already logs exception responses
+
+  // Publish a sensor if its register(s) are in this response; skipping absent registers keeps this
+  // correct for any read range, so the poll may be split into multiple requests.
+  auto publish_1_register = [&](sensor::Sensor *sensor, uint16_t reg, float divisor) -> void {
+    if (sensor == nullptr)
+      return;
+    if (auto value = helpers::value_at<helpers::SensorValueType::U_WORD>(registers, start_address, reg))
+      sensor->publish_state(*value / divisor);
+  };
+
+  auto publish_2_registers = [&](sensor::Sensor *sensor, uint16_t reg, float divisor) -> void {
+    if (sensor == nullptr)
+      return;
+    if (auto value = helpers::value_at<helpers::SensorValueType::U_DWORD_R>(registers, start_address, reg))
+      sensor->publish_state(*value / divisor);
+  };
+
+  publish_1_register(this->voltage_sensor_, PZEM_REGISTER_VOLTAGE, 10.0f);
+  publish_2_registers(this->current_sensor_, PZEM_REGISTER_CURRENT, 1000.0f);
+  publish_2_registers(this->power_sensor_, PZEM_REGISTER_ACTIVE_POWER, 10.0f);
+  publish_2_registers(this->energy_sensor_, PZEM_REGISTER_ACTIVE_ENERGY, 1.0f);
+  publish_1_register(this->frequency_sensor_, PZEM_REGISTER_FREQUENCY, 10.0f);
+  publish_1_register(this->power_factor_sensor_, PZEM_REGISTER_POWER_FACTOR, 100.0f);
+}
+
+void PZEMAC::on_custom_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu,
+                                modbus::ResponseStatus status) {
+  // The only custom request this component sends is the energy reset; acknowledge its echo here so
+  // the default unhandled-response warning stays meaningful.
+  if (!request_pdu.empty() && request_pdu[0] == PZEM_CMD_RESET_ENERGY) {
+    if (modbus::succeeded(status)) {
+      ESP_LOGD(TAG, "Energy reset acknowledged");
+    } else {
+      ESP_LOGW(TAG, "Energy reset rejected");
+    }
     return;
   }
-
-  // See https://github.com/esphome/feature-requests/issues/49#issuecomment-538636809
-  //  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
-  // 01 04 14 08 D1 00 6C 00 00 00 F4 00 00 00 26 00 00 01 F4 00 64 00 00 51 34
-  // Id Cc Sz Volt- Current---- Power------ Energy----- Frequ PFact Alarm Crc--
-  //           0     2           6          10          14    16
-
-  auto pzem_get_16bit = [&](size_t i) -> uint16_t {
-    return (uint16_t(data[i + 0]) << 8) | (uint16_t(data[i + 1]) << 0);
-  };
-  auto pzem_get_32bit = [&](size_t i) -> uint32_t {
-    return (uint32_t(pzem_get_16bit(i + 2)) << 16) | (uint32_t(pzem_get_16bit(i + 0)) << 0);
-  };
-
-  uint16_t raw_voltage = pzem_get_16bit(0);
-  float voltage = raw_voltage / 10.0f;  // max 6553.5 V
-
-  uint32_t raw_current = pzem_get_32bit(2);
-  float current = raw_current / 1000.0f;  // max 4294967.295 A
-
-  uint32_t raw_active_power = pzem_get_32bit(6);
-  float active_power = raw_active_power / 10.0f;  // max 429496729.5 W
-
-  float active_energy = static_cast<float>(pzem_get_32bit(10));
-
-  uint16_t raw_frequency = pzem_get_16bit(14);
-  float frequency = raw_frequency / 10.0f;
-
-  uint16_t raw_power_factor = pzem_get_16bit(16);
-  float power_factor = raw_power_factor / 100.0f;
-
-  ESP_LOGD(TAG, "PZEM AC: V=%.1f V, I=%.3f A, P=%.1f W, E=%.1f Wh, F=%.1f Hz, PF=%.2f", voltage, current, active_power,
-           active_energy, frequency, power_factor);
-  if (this->voltage_sensor_ != nullptr)
-    this->voltage_sensor_->publish_state(voltage);
-  if (this->current_sensor_ != nullptr)
-    this->current_sensor_->publish_state(current);
-  if (this->power_sensor_ != nullptr)
-    this->power_sensor_->publish_state(active_power);
-  if (this->energy_sensor_ != nullptr)
-    this->energy_sensor_->publish_state(active_energy);
-  if (this->frequency_sensor_ != nullptr)
-    this->frequency_sensor_->publish_state(frequency);
-  if (this->power_factor_sensor_ != nullptr)
-    this->power_factor_sensor_->publish_state(power_factor);
+  modbus::ModbusClientDevice::on_custom_response(request_pdu, response_pdu, status);
 }
 
 void PZEMAC::update() { this->read_input_registers(0, PZEM_REGISTER_COUNT); }

esphome/components/pzemac/pzemac.h

@@ -22,7 +22,10 @@ class PZEMAC final : public PollingComponent, public modbus::ModbusClientDevice
 
   void update() override;
 
-  void on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) override;
+  void on_read_input_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                               modbus::ResponseStatus status) override;
+  void on_custom_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu,
+                          modbus::ResponseStatus status) override;
 
   void dump_config() override;
 

esphome/components/pzemdc/pzemdc.cpp

@@ -3,55 +3,63 @@
 
 namespace esphome::pzemdc {
 
+namespace helpers = modbus::helpers;
+
 static const char *const TAG = "pzemdc";
 
 static const uint8_t PZEM_CMD_RESET_ENERGY = 0x42;
-static const uint8_t PZEM_REGISTER_COUNT = 10;  // 10x 16-bit registers
+static const uint8_t PZEM_REGISTER_COUNT = 8;  // 8x 16-bit registers
 
-void PZEMDC::on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) {
-  auto data = modbus::helpers::server_pdu_payload(response_pdu);
-  if (data.size() < 16) {
-    ESP_LOGW(TAG, "Invalid size for PZEM DC!");
-    return;
-  }
+// Register map, see https://github.com/esphome/feature-requests/issues/49#issuecomment-538636809
+// 32-bit values are two registers, low word first.
+static const uint16_t PZEM_REGISTER_VOLTAGE = 0;  // 1 register, 0.01 V
+static const uint16_t PZEM_REGISTER_CURRENT = 1;  // 1 register, 0.01 A
+static const uint16_t PZEM_REGISTER_POWER = 2;    // 2 registers, 0.1 W
+static const uint16_t PZEM_REGISTER_ENERGY = 4;   // 2 registers, 1 Wh
 
-  // See https://github.com/esphome/feature-requests/issues/49#issuecomment-538636809
-  //           0     1     2     3     4     5     6     7           = ModBus register
-  //  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20  = Buffer index
-  // 01 04 10 05 40 00 0A 00 0D 00 00 00 02 00 00 00 00 00 00 D6 29
-  // Id Cc Sz Volt- Curre Power------ Energy----- HiAlm LoAlm Crc--
+void PZEMDC::on_read_input_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                                     modbus::ResponseStatus status) {
+  if (!modbus::succeeded(status))
+    return;  // the hub already logs exception responses
 
-  auto pzem_get_16bit = [&](size_t i) -> uint16_t {
-    return (uint16_t(data[i + 0]) << 8) | (uint16_t(data[i + 1]) << 0);
-  };
-  auto pzem_get_32bit = [&](size_t i) -> uint32_t {
-    return (uint32_t(pzem_get_16bit(i + 2)) << 16) | (uint32_t(pzem_get_16bit(i + 0)) << 0);
+  // Publish a sensor if its register(s) are in this response; skipping absent registers keeps this
+  // correct for any read range, so the poll may be split into multiple requests.
+  auto publish_1_register = [&](sensor::Sensor *sensor, uint16_t reg, float divisor) -> void {
+    if (sensor == nullptr)
+      return;
+    if (auto value = helpers::value_at<helpers::SensorValueType::U_WORD>(registers, start_address, reg))
+      sensor->publish_state(*value / divisor);
   };
 
-  uint16_t raw_voltage = pzem_get_16bit(0);
-  float voltage = raw_voltage / 100.0f;  // max 655.35 V
+  auto publish_2_registers = [&](sensor::Sensor *sensor, uint16_t reg, float divisor) -> void {
+    if (sensor == nullptr)
+      return;
+    if (auto value = helpers::value_at<helpers::SensorValueType::U_DWORD_R>(registers, start_address, reg))
+      sensor->publish_state(*value / divisor);
+  };
 
-  uint16_t raw_current = pzem_get_16bit(2);
-  float current = raw_current / 100.0f;  // max 655.35 A
-
-  uint32_t raw_power = pzem_get_32bit(4);
-  float power = raw_power / 10.0f;  // max 429496729.5 W
-
-  uint32_t raw_energy = pzem_get_32bit(8);
-  float energy = raw_energy / 1000.0f;  // max 4294967.295 kWh
-
-  ESP_LOGD(TAG, "PZEM DC: V=%.1f V, I=%.3f A, P=%.1f W", voltage, current, power);
-  if (this->voltage_sensor_ != nullptr)
-    this->voltage_sensor_->publish_state(voltage);
-  if (this->current_sensor_ != nullptr)
-    this->current_sensor_->publish_state(current);
-  if (this->power_sensor_ != nullptr)
-    this->power_sensor_->publish_state(power);
-  if (this->energy_sensor_ != nullptr)
-    this->energy_sensor_->publish_state(energy);
+  publish_1_register(this->voltage_sensor_, PZEM_REGISTER_VOLTAGE, 100.0f);
+  publish_1_register(this->current_sensor_, PZEM_REGISTER_CURRENT, 100.0f);
+  publish_2_registers(this->power_sensor_, PZEM_REGISTER_POWER, 10.0f);
+  publish_2_registers(this->energy_sensor_, PZEM_REGISTER_ENERGY, 1000.0f);
 }
 
-void PZEMDC::update() { this->read_input_registers(0, 8); }
+void PZEMDC::on_custom_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu,
+                                modbus::ResponseStatus status) {
+  // The only custom request this component sends is the energy reset; acknowledge its echo here so
+  // the default unhandled-response warning stays meaningful.
+  if (!request_pdu.empty() && request_pdu[0] == PZEM_CMD_RESET_ENERGY) {
+    if (modbus::succeeded(status)) {
+      ESP_LOGD(TAG, "Energy reset acknowledged");
+    } else {
+      ESP_LOGW(TAG, "Energy reset rejected");
+    }
+    return;
+  }
+  modbus::ModbusClientDevice::on_custom_response(request_pdu, response_pdu, status);
+}
+
+void PZEMDC::update() { this->read_input_registers(0, PZEM_REGISTER_COUNT); }
 void PZEMDC::dump_config() {
   ESP_LOGCONFIG(TAG,
                 "PZEMDC:\n"

esphome/components/pzemdc/pzemdc.h

@@ -18,7 +18,10 @@ class PZEMDC final : public PollingComponent, public modbus::ModbusClientDevice
 
   void update() override;
 
-  void on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) override;
+  void on_read_input_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                               modbus::ResponseStatus status) override;
+  void on_custom_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu,
+                          modbus::ResponseStatus status) override;
 
   void dump_config() override;
 

esphome/components/sdm_meter/sdm_meter.cpp

@@ -1,85 +1,48 @@
 #include "sdm_meter.h"
 #include "sdm_meter_registers.h"
-#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 namespace esphome::sdm_meter {
 
+namespace helpers = modbus::helpers;
+
 static const char *const TAG = "sdm_meter";
 
-static const uint8_t MODBUS_REGISTER_COUNT = 80;  // 74 x 16-bit registers
+static const uint8_t MODBUS_REGISTER_COUNT = 80;  // 80 x 16-bit registers (40 float values)
 
-void SDMMeter::on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) {
-  auto data = modbus::helpers::server_pdu_payload(response_pdu);
-  if (data.size() < MODBUS_REGISTER_COUNT * 2) {
-    ESP_LOGW(TAG, "Invalid size for SDMMeter!");
-    return;
-  }
+void SDMMeter::on_read_input_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                                       modbus::ResponseStatus status) {
+  if (!modbus::succeeded(status))
+    return;  // the hub already logs exception responses
 
-  auto sdm_meter_get_float = [&](size_t i) -> float {
-    uint32_t temp = encode_uint32(data[i], data[i + 1], data[i + 2], data[i + 3]);
-    float f;
-    memcpy(&f, &temp, sizeof(f));
-    return f;
+  // Publish a sensor if both of its registers are in this response; skipping absent registers keeps
+  // this correct for any read range, so the poll may be split into multiple requests.
+  auto publish = [&](uint16_t reg, sensor::Sensor *sensor) {
+    if (sensor == nullptr)
+      return;
+    if (auto value = helpers::value_at<helpers::SensorValueType::FP32>(registers, start_address, reg))
+      sensor->publish_state(*value);
   };
 
   for (uint8_t i = 0; i < 3; i++) {
-    auto phase = this->phases_[i];
+    auto &phase = this->phases_[i];
     if (!phase.setup)
       continue;
-
-    float voltage = sdm_meter_get_float(SDM_PHASE_1_VOLTAGE * 2 + (i * 4));
-    float current = sdm_meter_get_float(SDM_PHASE_1_CURRENT * 2 + (i * 4));
-    float active_power = sdm_meter_get_float(SDM_PHASE_1_ACTIVE_POWER * 2 + (i * 4));
-    float apparent_power = sdm_meter_get_float(SDM_PHASE_1_APPARENT_POWER * 2 + (i * 4));
-    float reactive_power = sdm_meter_get_float(SDM_PHASE_1_REACTIVE_POWER * 2 + (i * 4));
-    float power_factor = sdm_meter_get_float(SDM_PHASE_1_POWER_FACTOR * 2 + (i * 4));
-    float phase_angle = sdm_meter_get_float(SDM_PHASE_1_ANGLE * 2 + (i * 4));
-
-    ESP_LOGD(
-        TAG,
-        "SDMMeter Phase %c: V=%.3f V, I=%.3f A, Active P=%.3f W, Apparent P=%.3f VA, Reactive P=%.3f var, PF=%.3f, "
-        "PA=%.3f °",
-        i + 'A', voltage, current, active_power, apparent_power, reactive_power, power_factor, phase_angle);
-    if (phase.voltage_sensor_ != nullptr)
-      phase.voltage_sensor_->publish_state(voltage);
-    if (phase.current_sensor_ != nullptr)
-      phase.current_sensor_->publish_state(current);
-    if (phase.active_power_sensor_ != nullptr)
-      phase.active_power_sensor_->publish_state(active_power);
-    if (phase.apparent_power_sensor_ != nullptr)
-      phase.apparent_power_sensor_->publish_state(apparent_power);
-    if (phase.reactive_power_sensor_ != nullptr)
-      phase.reactive_power_sensor_->publish_state(reactive_power);
-    if (phase.power_factor_sensor_ != nullptr)
-      phase.power_factor_sensor_->publish_state(power_factor);
-    if (phase.phase_angle_sensor_ != nullptr)
-      phase.phase_angle_sensor_->publish_state(phase_angle);
+    publish(SDM_PHASE_1_VOLTAGE + i * 2, phase.voltage_sensor_);
+    publish(SDM_PHASE_1_CURRENT + i * 2, phase.current_sensor_);
+    publish(SDM_PHASE_1_ACTIVE_POWER + i * 2, phase.active_power_sensor_);
+    publish(SDM_PHASE_1_APPARENT_POWER + i * 2, phase.apparent_power_sensor_);
+    publish(SDM_PHASE_1_REACTIVE_POWER + i * 2, phase.reactive_power_sensor_);
+    publish(SDM_PHASE_1_POWER_FACTOR + i * 2, phase.power_factor_sensor_);
+    publish(SDM_PHASE_1_ANGLE + i * 2, phase.phase_angle_sensor_);
   }
 
-  float total_power = sdm_meter_get_float(SDM_TOTAL_SYSTEM_POWER * 2);
-  float frequency = sdm_meter_get_float(SDM_FREQUENCY * 2);
-  float import_active_energy = sdm_meter_get_float(SDM_IMPORT_ACTIVE_ENERGY * 2);
-  float export_active_energy = sdm_meter_get_float(SDM_EXPORT_ACTIVE_ENERGY * 2);
-  float import_reactive_energy = sdm_meter_get_float(SDM_IMPORT_REACTIVE_ENERGY * 2);
-  float export_reactive_energy = sdm_meter_get_float(SDM_EXPORT_REACTIVE_ENERGY * 2);
-
-  ESP_LOGD(TAG, "SDMMeter: F=%.3f Hz, Im.A.E=%.3f Wh, Ex.A.E=%.3f Wh, Im.R.E=%.3f VARh, Ex.R.E=%.3f VARh, T.P=%.3f W",
-           frequency, import_active_energy, export_active_energy, import_reactive_energy, export_reactive_energy,
-           total_power);
-
-  if (this->total_power_sensor_ != nullptr)
-    this->total_power_sensor_->publish_state(total_power);
-  if (this->frequency_sensor_ != nullptr)
-    this->frequency_sensor_->publish_state(frequency);
-  if (this->import_active_energy_sensor_ != nullptr)
-    this->import_active_energy_sensor_->publish_state(import_active_energy);
-  if (this->export_active_energy_sensor_ != nullptr)
-    this->export_active_energy_sensor_->publish_state(export_active_energy);
-  if (this->import_reactive_energy_sensor_ != nullptr)
-    this->import_reactive_energy_sensor_->publish_state(import_reactive_energy);
-  if (this->export_reactive_energy_sensor_ != nullptr)
-    this->export_reactive_energy_sensor_->publish_state(export_reactive_energy);
+  publish(SDM_TOTAL_SYSTEM_POWER, this->total_power_sensor_);
+  publish(SDM_FREQUENCY, this->frequency_sensor_);
+  publish(SDM_IMPORT_ACTIVE_ENERGY, this->import_active_energy_sensor_);
+  publish(SDM_EXPORT_ACTIVE_ENERGY, this->export_active_energy_sensor_);
+  publish(SDM_IMPORT_REACTIVE_ENERGY, this->import_reactive_energy_sensor_);
+  publish(SDM_EXPORT_REACTIVE_ENERGY, this->export_reactive_energy_sensor_);
 }
 
 void SDMMeter::update() { this->read_input_registers(0, MODBUS_REGISTER_COUNT); }

esphome/components/sdm_meter/sdm_meter.h

@@ -55,7 +55,8 @@ class SDMMeter final : public PollingComponent, public modbus::ModbusClientDevic
 
   void update() override;
 
-  void on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) override;
+  void on_read_input_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                               modbus::ResponseStatus status) override;
 
   void dump_config() override;
 

esphome/components/selec_meter/selec_meter.cpp

@@ -1,84 +1,47 @@
 #include "selec_meter.h"
 #include "selec_meter_registers.h"
-#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 namespace esphome::selec_meter {
 
+namespace helpers = modbus::helpers;
+
 static const char *const TAG = "selec_meter";
 
 static const uint8_t MODBUS_REGISTER_COUNT = 34;  // 34 x 16-bit registers
 
-void SelecMeter::on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) {
-  auto data = modbus::helpers::server_pdu_payload(response_pdu);
-  if (data.size() < MODBUS_REGISTER_COUNT * 2) {
-    ESP_LOGW(TAG, "Invalid size for SelecMeter!");
-    return;
-  }
+void SelecMeter::on_read_input_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                                         modbus::ResponseStatus status) {
+  if (!modbus::succeeded(status))
+    return;  // the hub already logs exception responses
 
-  auto selec_meter_get_float = [&](size_t i, float unit) -> float {
-    uint32_t temp = encode_uint32(data[i + 2], data[i + 3], data[i], data[i + 1]);
-
-    float f;
-    memcpy(&f, &temp, sizeof(f));
-    return (f * unit);
+  // Publish a sensor if both of its registers are in this response; skipping absent registers keeps
+  // this correct for any read range, so the poll may be split into multiple requests.
+  // Values are 32-bit floats, low word first.
+  auto publish = [&](sensor::Sensor *sensor, uint16_t reg, float unit) -> void {
+    if (sensor == nullptr)
+      return;
+    if (auto value = helpers::value_at<helpers::SensorValueType::FP32_R>(registers, start_address, reg))
+      sensor->publish_state(*value * unit);
   };
 
-  float total_active_energy = selec_meter_get_float(SELEC_TOTAL_ACTIVE_ENERGY * 2, NO_DEC_UNIT);
-  float import_active_energy = selec_meter_get_float(SELEC_IMPORT_ACTIVE_ENERGY * 2, NO_DEC_UNIT);
-  float export_active_energy = selec_meter_get_float(SELEC_EXPORT_ACTIVE_ENERGY * 2, NO_DEC_UNIT);
-  float total_reactive_energy = selec_meter_get_float(SELEC_TOTAL_REACTIVE_ENERGY * 2, NO_DEC_UNIT);
-  float import_reactive_energy = selec_meter_get_float(SELEC_IMPORT_REACTIVE_ENERGY * 2, NO_DEC_UNIT);
-  float export_reactive_energy = selec_meter_get_float(SELEC_EXPORT_REACTIVE_ENERGY * 2, NO_DEC_UNIT);
-  float apparent_energy = selec_meter_get_float(SELEC_APPARENT_ENERGY * 2, NO_DEC_UNIT);
-  float active_power = selec_meter_get_float(SELEC_ACTIVE_POWER * 2, MULTIPLY_THOUSAND_UNIT);
-  float reactive_power = selec_meter_get_float(SELEC_REACTIVE_POWER * 2, MULTIPLY_THOUSAND_UNIT);
-  float apparent_power = selec_meter_get_float(SELEC_APPARENT_POWER * 2, MULTIPLY_THOUSAND_UNIT);
-  float voltage = selec_meter_get_float(SELEC_VOLTAGE * 2, NO_DEC_UNIT);
-  float current = selec_meter_get_float(SELEC_CURRENT * 2, NO_DEC_UNIT);
-  float power_factor = selec_meter_get_float(SELEC_POWER_FACTOR * 2, NO_DEC_UNIT);
-  float frequency = selec_meter_get_float(SELEC_FREQUENCY * 2, NO_DEC_UNIT);
-  float maximum_demand_active_power =
-      selec_meter_get_float(SELEC_MAXIMUM_DEMAND_ACTIVE_POWER * 2, MULTIPLY_THOUSAND_UNIT);
-  float maximum_demand_reactive_power =
-      selec_meter_get_float(SELEC_MAXIMUM_DEMAND_REACTIVE_POWER * 2, MULTIPLY_THOUSAND_UNIT);
-  float maximum_demand_apparent_power =
-      selec_meter_get_float(SELEC_MAXIMUM_DEMAND_APPARENT_POWER * 2, MULTIPLY_THOUSAND_UNIT);
-
-  if (this->total_active_energy_sensor_ != nullptr)
-    this->total_active_energy_sensor_->publish_state(total_active_energy);
-  if (this->import_active_energy_sensor_ != nullptr)
-    this->import_active_energy_sensor_->publish_state(import_active_energy);
-  if (this->export_active_energy_sensor_ != nullptr)
-    this->export_active_energy_sensor_->publish_state(export_active_energy);
-  if (this->total_reactive_energy_sensor_ != nullptr)
-    this->total_reactive_energy_sensor_->publish_state(total_reactive_energy);
-  if (this->import_reactive_energy_sensor_ != nullptr)
-    this->import_reactive_energy_sensor_->publish_state(import_reactive_energy);
-  if (this->export_reactive_energy_sensor_ != nullptr)
-    this->export_reactive_energy_sensor_->publish_state(export_reactive_energy);
-  if (this->apparent_energy_sensor_ != nullptr)
-    this->apparent_energy_sensor_->publish_state(apparent_energy);
-  if (this->active_power_sensor_ != nullptr)
-    this->active_power_sensor_->publish_state(active_power);
-  if (this->reactive_power_sensor_ != nullptr)
-    this->reactive_power_sensor_->publish_state(reactive_power);
-  if (this->apparent_power_sensor_ != nullptr)
-    this->apparent_power_sensor_->publish_state(apparent_power);
-  if (this->voltage_sensor_ != nullptr)
-    this->voltage_sensor_->publish_state(voltage);
-  if (this->current_sensor_ != nullptr)
-    this->current_sensor_->publish_state(current);
-  if (this->power_factor_sensor_ != nullptr)
-    this->power_factor_sensor_->publish_state(power_factor);
-  if (this->frequency_sensor_ != nullptr)
-    this->frequency_sensor_->publish_state(frequency);
-  if (this->maximum_demand_active_power_sensor_ != nullptr)
-    this->maximum_demand_active_power_sensor_->publish_state(maximum_demand_active_power);
-  if (this->maximum_demand_reactive_power_sensor_ != nullptr)
-    this->maximum_demand_reactive_power_sensor_->publish_state(maximum_demand_reactive_power);
-  if (this->maximum_demand_apparent_power_sensor_ != nullptr)
-    this->maximum_demand_apparent_power_sensor_->publish_state(maximum_demand_apparent_power);
+  publish(this->total_active_energy_sensor_, SELEC_TOTAL_ACTIVE_ENERGY, NO_DEC_UNIT);
+  publish(this->import_active_energy_sensor_, SELEC_IMPORT_ACTIVE_ENERGY, NO_DEC_UNIT);
+  publish(this->export_active_energy_sensor_, SELEC_EXPORT_ACTIVE_ENERGY, NO_DEC_UNIT);
+  publish(this->total_reactive_energy_sensor_, SELEC_TOTAL_REACTIVE_ENERGY, NO_DEC_UNIT);
+  publish(this->import_reactive_energy_sensor_, SELEC_IMPORT_REACTIVE_ENERGY, NO_DEC_UNIT);
+  publish(this->export_reactive_energy_sensor_, SELEC_EXPORT_REACTIVE_ENERGY, NO_DEC_UNIT);
+  publish(this->apparent_energy_sensor_, SELEC_APPARENT_ENERGY, NO_DEC_UNIT);
+  publish(this->active_power_sensor_, SELEC_ACTIVE_POWER, MULTIPLY_THOUSAND_UNIT);
+  publish(this->reactive_power_sensor_, SELEC_REACTIVE_POWER, MULTIPLY_THOUSAND_UNIT);
+  publish(this->apparent_power_sensor_, SELEC_APPARENT_POWER, MULTIPLY_THOUSAND_UNIT);
+  publish(this->voltage_sensor_, SELEC_VOLTAGE, NO_DEC_UNIT);
+  publish(this->current_sensor_, SELEC_CURRENT, NO_DEC_UNIT);
+  publish(this->power_factor_sensor_, SELEC_POWER_FACTOR, NO_DEC_UNIT);
+  publish(this->frequency_sensor_, SELEC_FREQUENCY, NO_DEC_UNIT);
+  publish(this->maximum_demand_active_power_sensor_, SELEC_MAXIMUM_DEMAND_ACTIVE_POWER, MULTIPLY_THOUSAND_UNIT);
+  publish(this->maximum_demand_reactive_power_sensor_, SELEC_MAXIMUM_DEMAND_REACTIVE_POWER, MULTIPLY_THOUSAND_UNIT);
+  publish(this->maximum_demand_apparent_power_sensor_, SELEC_MAXIMUM_DEMAND_APPARENT_POWER, MULTIPLY_THOUSAND_UNIT);
 }
 
 void SelecMeter::update() { this->read_input_registers(0, MODBUS_REGISTER_COUNT); }

esphome/components/selec_meter/selec_meter.h

@@ -37,7 +37,8 @@ class SelecMeter final : public PollingComponent, public modbus::ModbusClientDev
 
   void update() override;
 
-  void on_response(std::span<const uint8_t> request_pdu, std::span<const uint8_t> response_pdu) override;
+  void on_read_input_registers(uint16_t start_address, std::span<const uint16_t> registers,
+                               modbus::ResponseStatus status) override;
 
   void dump_config() override;
 };

esphome/components/zigbee/zigbee_esp32.py

@@ -9,6 +9,7 @@ from esphome.components.esp32 import (
     add_idf_component,
     add_idf_sdkconfig_option,
     add_partition,
+    include_builtin_idf_component,
     require_vfs_select,
 )
 import esphome.config_validation as cv
@@ -288,6 +289,10 @@ async def esp32_to_code(config: ConfigType) -> "MockObj":
         ref="2.0.4",
     )
 
+    if CONF_WIFI in CORE.config:
+        # zigbee_esp32.cpp uses esp_coexist.h when WiFi is present
+        include_builtin_idf_component("esp_coex")
+
     # add sdkconfigs later so they can overwrite esp32 defaults
     CORE.add_job(_zigbee_add_sdkconfigs, config)
 

esphome/core/__init__.py

@@ -783,7 +783,8 @@ class EsphomeCore:
         can compare a locally computed hash against the one a device
         advertises. Machine-local data is kept out of the input: build_path
         (which embeds ESPHOME_BUILD_PATH and OS path separators) is excluded,
-        and Path values are dumped relative to the config directory.
+        and Path values are dumped relative to the config directory, with
+        the data directory always at its default ``.esphome`` location.
         """
         if self._config_hash is None:
             from esphome import yaml_util
@@ -794,11 +795,15 @@ class EsphomeCore:
                 esphome_conf = dict(esphome_conf)
                 esphome_conf.pop(CONF_BUILD_PATH, None)
                 config[CONF_ESPHOME] = esphome_conf
+            relative_to = data_dir = None
+            if self.config_path is not None:
+                relative_to, data_dir = self.config_dir, self.data_dir
             config_str = yaml_util.dump(
                 config,
                 show_secrets=True,
                 sort_keys=True,
-                relative_to=self.config_dir if self.config_path is not None else None,
+                relative_to=relative_to,
+                data_dir=data_dir,
             )
             self._config_hash = fnv1a_32bit_hash(config_str)
         return self._config_hash

esphome/core/component.cpp

@@ -336,10 +336,8 @@ void log_update_interval(const char *tag, PollingComponent *component) {
   uint32_t update_interval = component->get_update_interval();
   if (update_interval == SCHEDULER_DONT_RUN) {
     ESP_LOGCONFIG(tag, "  Update Interval: never");
-  } else if (update_interval < 100) {
-    ESP_LOGCONFIG(tag, "  Update Interval: %.3fs", update_interval / 1000.0f);
   } else {
-    ESP_LOGCONFIG(tag, "  Update Interval: %.1fs", update_interval / 1000.0f);
+    ESP_LOGCONFIG(tag, "  Update Interval: %" PRIu32 ".%03" PRIu32 "s", update_interval / 1000, update_interval % 1000);
   }
 }
 float Component::get_actual_setup_priority() const {

esphome/core/defines.h

@@ -134,6 +134,7 @@
 #define MDNS_DYNAMIC_TXT_COUNT 2
 #define MICRONOVA_LISTENER_COUNT 1
 #define USE_MICRONOVA_WRITER
+#define MK2PVROUTER_LISTENER_COUNT 1
 #define SERIAL_PROXY_COUNT 2
 #define SNTP_SERVER_COUNT 3
 #define USE_MEDIA_PLAYER
@@ -217,9 +218,11 @@
 #define USE_API_PLAINTEXT
 #define USE_API_USER_DEFINED_ACTIONS
 #define USE_API_CUSTOM_SERVICES
+#define USE_API_USER_DEFINED_ACTION_METADATA
 #define USE_API_USER_DEFINED_ACTION_RESPONSES
 #define USE_API_USER_DEFINED_ACTION_RESPONSES_JSON
 #define API_MAX_SEND_QUEUE 8
+#define API_USER_ACTION_STRINGS_SCRATCH_SIZE 64
 #define MAX_API_CONNECTIONS 6
 // The Improv library is not in the Zephyr tidy environment
 #define USE_IMPROV_SERIAL

esphome/core/helpers.cpp

@@ -568,7 +568,7 @@ size_t value_accuracy_to_buf(std::span<char, VALUE_ACCURACY_MAX_LEN> buf, float
   }
 
   // Fallback for NaN/Inf/high accuracy/out-of-range
-  int len = snprintf(buf.data(), buf.size(), "%.*f", accuracy_decimals, value);
+  int len = snprintf(buf.data(), buf.size(), "%.*f", accuracy_decimals, static_cast<double>(value));
   if (len < 0)
     return 0;
   return static_cast<size_t>(len) >= buf.size() ? buf.size() - 1 : static_cast<size_t>(len);
@@ -586,16 +586,30 @@ size_t value_accuracy_with_uom_to_buf(std::span<char, VALUE_ACCURACY_MAX_LEN> bu
 }
 
 int8_t step_to_accuracy_decimals(float step) {
-  // use printf %g to find number of digits based on temperature step
-  char buf[32];
-  snprintf(buf, sizeof buf, "%.5g", step);
-
-  std::string str{buf};
-  size_t dot_pos = str.find('.');
-  if (dot_pos == std::string::npos)
+  // Decimals needed to show the step at five significant digits, trailing zeros dropped.
+  if (!std::isfinite(step) || step == 0.0f)
     return 0;
-
-  return str.length() - dot_pos - 1;
+  float mantissa = std::fabs(step);
+  int8_t decimals = 4;  // decimals needed for five significant digits when mantissa is in [1, 10)
+  while (mantissa >= 10.0f) {
+    mantissa /= 10.0f;
+    decimals--;
+  }
+  while (mantissa < 1.0f) {
+    mantissa *= 10.0f;
+    decimals++;
+  }
+  if (decimals <= 0)
+    return 0;
+  float scaled = mantissa * 10000.0f;
+  auto digits = static_cast<uint32_t>(scaled);
+  if (scaled - static_cast<float>(digits) >= 0.5f)
+    digits++;
+  while (decimals > 0 && digits % 10 == 0) {
+    digits /= 10;
+    decimals--;
+  }
+  return decimals;
 }
 
 // Map a base64/base64url character to its 6-bit value (0-63) arithmetically.

esphome/core/helpers.h

@@ -290,6 +290,7 @@ template<typename T, size_t N> class StaticVector {
   }
 
   size_t size() const { return count_; }
+  static constexpr size_t capacity() { return N; }
   bool empty() const { return count_ == 0; }
 
   // Direct access to underlying data

esphome/cpp_types.py

@@ -14,6 +14,7 @@ std_string_ref = std_ns.namespace("string &")
 std_vector = std_ns.class_("vector")
 std_span = std_ns.class_("span")
 int8 = global_ns.namespace("int8_t")
+char = global_ns.namespace("char")
 uint8 = global_ns.namespace("uint8_t")
 uint16 = global_ns.namespace("uint16_t")
 uint32 = global_ns.namespace("uint32_t")

esphome/espidf/framework.py

@@ -1053,15 +1053,28 @@ def _check_esp_idf_python_env_install(
             constraint_file_path,
         )
 
-        cmd_pip_install = [
-            str(env_python_path),
-            "-m",
-            "pip",
-            "install",
-            "--upgrade",
-            "--constraint",
-            constraint_file_path,
-        ]
+        # uv (much faster than pip) when available, e.g. in the docker image
+        if uv_path := shutil.which("uv"):
+            cmd_pip_install = [
+                uv_path,
+                "pip",
+                "install",
+                "--python",
+                str(env_python_path),
+                "--upgrade",
+                "--constraint",
+                str(constraint_file_path),
+            ]
+        else:
+            cmd_pip_install = [
+                str(env_python_path),
+                "-m",
+                "pip",
+                "install",
+                "--upgrade",
+                "--constraint",
+                str(constraint_file_path),
+            ]
 
         _LOGGER.info("Installing ESP-IDF %s Python dependencies ...", version)
         cmd = cmd_pip_install + [
@@ -1135,6 +1148,8 @@ def check_esp_idf_install(
     env = {}
     env["IDF_TOOLS_PATH"] = str(get_idf_tools_path())
     env["IDF_PATH"] = ""
+    # uv defaults to 3 HTTP retries; match the pioarduino penv's bump to 10
+    env["UV_HTTP_RETRIES"] = os.environ.get("UV_HTTP_RETRIES", "10")
 
     # An explicit ESPHOME_IDF_DEFAULT_TARGETS wins over the caller's
     # per-variant request (builder-image pre-warm); otherwise the caller's

esphome/helpers.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from collections.abc import Iterable, MutableMapping
+from collections.abc import Callable, Iterable, MutableMapping
 from contextlib import suppress
 import ipaddress
 import logging
@@ -456,23 +456,55 @@ def add_git_ceiling_directory(env: MutableMapping[str, str], directory: Path) ->
         env["GIT_CEILING_DIRECTORIES"] = os.pathsep.join(parts)
 
 
-def rmtree(path: Path | str) -> None:
-    """Remove a directory tree, handling read-only files on Windows.
+# Deletion attempts when a directory keeps being repopulated mid-delete
+RMTREE_MAX_ATTEMPTS = 3
 
-    On Windows, git pack files and other files may be marked read-only,
-    causing shutil.rmtree to fail. This handles that by removing the
-    read-only flag and retrying.
+
+def rmtree(path: Path | str) -> None:
+    """Remove a directory tree, tolerating common filesystem races.
+
+    Read-only files (e.g. git pack files on Windows) get the read-only flag
+    removed and are retried. Paths that are already gone, whether the target
+    itself or entries vanishing mid-delete, are treated as removed.
+    Directories repopulated mid-delete (e.g. Finder recreating .DS_Store on
+    macOS) are retried a few times.
     """
 
+    import errno
     import shutil
+    import time
 
-    def _onexc(func, path, exc):
+    def _onexc(func: Callable[..., object], path: str | Path, exc: OSError) -> None:
+        if isinstance(exc, FileNotFoundError):
+            _LOGGER.debug("rmtree: %s already gone", path)
+            return
         if os.access(path, os.W_OK):
             raise exc
         Path(path).chmod(stat.S_IWUSR | stat.S_IRUSR)
         func(path)
 
-    shutil.rmtree(path, onexc=_onexc)
+    last_err: OSError | None = None
+    for attempt in range(RMTREE_MAX_ATTEMPTS - 1):
+        try:
+            shutil.rmtree(path, onexc=_onexc)
+            return
+        except OSError as err:
+            if err.errno not in (errno.ENOTEMPTY, errno.EEXIST):
+                raise
+            _LOGGER.debug(
+                "rmtree: %s repopulated mid-delete (attempt %d): %s",
+                path,
+                attempt + 1,
+                err,
+            )
+            last_err = err
+            # Give the racing writer (e.g. Finder) time to settle
+            time.sleep(0.05 * (attempt + 1))
+    try:
+        shutil.rmtree(path, onexc=_onexc)
+    except OSError as err:
+        # Keep the earlier races visible in the traceback
+        raise err from last_err
 
 
 def walk_files(path: Path):

esphome/idf_component.yml

@@ -24,7 +24,7 @@ dependencies:
   espressif/esp32-camera:
     version: 2.1.7
   espressif/mdns:
-    version: 1.11.3
+    version: 1.12.0
   espressif/esp_wifi_remote:
     version: 1.6.3
     rules:

esphome/platformio/library.py

@@ -74,6 +74,11 @@ SOURCE_KIND_FOR_SUFFIX: dict[str, str] = {
     ".ASM": "asm",
 }
 SRC_FILE_EXTENSIONS = list(SOURCE_KIND_FOR_SUFFIX)
+# Suffixes that count as headers when probing whether a library has any
+# usable files at all (compare against Path.suffix.lower())
+LIBRARY_HEADER_SUFFIXES = frozenset(
+    {".h", ".hpp", ".hh", ".hxx", ".inc", ".ipp", ".tcc"}
+)
 
 DOMAIN = "pio_components"
 
@@ -329,6 +334,11 @@ class LibraryBackend:
     framework: str
     emit: Callable[["ConvertedLibrary"], None]
     cache_key: str
+    # Owner-less names this returns True for are skipped by the walk;
+    # the backend supplies them itself (e.g. core-bundled libraries) and
+    # reconciles provided_requests after resolving
+    provides: Callable[[str], bool] | None = None
+    provided_requests: set[str] = field(default_factory=set)
 
 
 def ensure_list[T](obj: T | list[T]) -> list[T]:
@@ -469,7 +479,7 @@ def _valid_manifest_shape(data: Any) -> bool:
     )
 
 
-def check_library_data(data: dict, platform: str | None, framework: str):
+def check_library_data(data: dict, platform: str | None, framework: str | None):
     """
     Check whether a library manifest is compatible with the target toolchain.
 
@@ -486,7 +496,8 @@ def check_library_data(data: dict, platform: str | None, framework: str):
             for targets (e.g. Zephyr) where PIO manifests rarely declare the
             platform yet portable libraries still build.
         framework: The active framework name (e.g. ``espidf``, ``arduino``,
-            ``zephyr``) the manifest is expected to declare.
+            ``zephyr``) the manifest is expected to declare. ``None`` skips
+            the framework check (and its warning), mirroring ``platform``.
 
     Raises:
         InvalidLibrary: If the library does not support the target platform.
@@ -517,7 +528,7 @@ def check_library_data(data: dict, platform: str | None, framework: str):
     # under the target framework, and there's no way to opt out of the check at
     # this layer. Warn instead of failing so the user isn't forced to fork the
     # library to fix the manifest.
-    valid_framework = "*" in frameworks or framework in frameworks
+    valid_framework = framework is None or "*" in frameworks or framework in frameworks
 
     if not valid_framework:
         _LOGGER.warning(
@@ -576,11 +587,15 @@ def _make_registry_client() -> Any:
     elsewhere, not by the PlatformIO registry.
     """
     from platformio.package.manager._registry import PackageManagerRegistryMixin
+    from platformio.registry.client import RegistryClient
 
     class _Registry(PackageManagerRegistryMixin):
         def __init__(self) -> None:
-            self._registry_client = None
             self.pkg_type = "library"
+            self._registry_client = RegistryClient()
+            # The probe sleeps ~500 ms per lookup (see runner.patch_registry_private_packages);
+            # instance-level so the ESPHome process never patches PlatformIO's class
+            self._registry_client.allowed_private_packages = lambda: False
 
         @staticmethod
         def is_system_compatible(value: Any, custom_system: Any = None) -> bool:
@@ -914,6 +929,56 @@ def is_lib_ignored(name: str | None, lib_ignore: set[str]) -> bool:
     )
 
 
+def _reconcile_versionless_skips(
+    skipped_versionless: list[tuple[Any, Any, str]],
+    components: dict[str, ConvertedLibrary],
+    backend: LibraryBackend,
+) -> None:
+    """Warn for version-less deps nothing satisfied, and record the
+    backend-provided ones in ``backend.provided_requests`` for its
+    post-emit reconciliation; a silent drop surfaces as link errors far
+    from the cause."""
+    resolved_manifest_names = {c.data.get("name") for c in components.values()}
+    # A treeless backend can never supply a bundled name; noise for it
+    log = _LOGGER.warning if backend.provides is not None else _LOGGER.debug
+    warned: set[str] = set()
+    for dep_name, dep_owner, requester in skipped_versionless:
+        if not isinstance(dep_name, str) or not dep_name or dep_name in warned:
+            continue
+        if dep_name in components:
+            # A version-less dep's request key is the name itself
+            continue
+        if (
+            not dep_owner
+            and backend.provides is not None
+            and backend.provides(dep_name)
+        ):
+            # provides() only satisfies owner-less names (same guard as
+            # the walk's skip); record for the post-emit reconciliation.
+            # Checked before the manifest-name evidence so the overlap
+            # case warns once, in the backend's own suppression loop
+            backend.provided_requests.add(dep_name)
+            continue
+        if dep_name in resolved_manifest_names:
+            # Name-only evidence: a coincidental collision must stay
+            # visible where the user could pin it
+            warned.add(dep_name)
+            log(
+                "Version-less dependency %s of %s assumed satisfied by a "
+                "resolved library's manifest name only",
+                dep_name,
+                requester,
+            )
+            continue
+        warned.add(dep_name)
+        log(
+            "Dependency %s of %s has no version to resolve and nothing "
+            "provides it; skipping",
+            dep_name,
+            requester,
+        )
+
+
 def _fetch_source(
     component: ConvertedLibrary,
     salt: str,
@@ -1083,6 +1148,8 @@ def convert_libraries(
     components: dict[str, ConvertedLibrary] = {}
     resolved_requirements: dict[str, frozenset[str]] = {}
     top_level_keys = set(top_level)
+    # (name, owner, requester) reconciled against the final resolution set
+    skipped_versionless: list[tuple[Any, Any, str]] = []
     worklist = deque(dict.fromkeys(top_level))
     while worklist:
         # Drain the frontier sequentially (spec resolution mutates shared
@@ -1187,13 +1254,23 @@ def convert_libraries(
                 component.data.get("dependencies"), component.name
             ):
                 if "version" not in dependency:
-                    # Cannot resolve from the registry; common for bundled
-                    # names (Wire, SPI) -- unactionable noise above debug
+                    # Cannot resolve from the registry; the post-emit
+                    # reconciliation owns the drop warning
+                    dep_name = dependency.get("name")
                     _LOGGER.debug(
                         "Skip version-less dependency %r of %s",
-                        dependency.get("name"),
+                        dep_name,
                         component.name,
                     )
+                    if not is_lib_ignored(
+                        dep_name, lib_ignore
+                    ) and dependency_is_usable(
+                        dependency, backend.platform, backend.framework, component.name
+                    ):
+                        # Filtered or ignored deps are deliberately absent
+                        skipped_versionless.append(
+                            (dep_name, dependency.get("owner"), component.name)
+                        )
                     continue
                 if not dependency_is_usable(
                     dependency, backend.platform, backend.framework, component.name
@@ -1205,11 +1282,31 @@ def convert_libraries(
                 if is_lib_ignored(dep_name, lib_ignore):
                     _LOGGER.debug("Skip ignored dependency %s", dep_name)
                     continue
-                # The version field may actually be a URL (git/archive dependency).
+                # The version may be a URL (git/archive), which names one
+                # specific source; never substitute a bundled library for it
                 dep_version = dependency["version"]
                 dep_url = _url_or_none(dep_version)
                 if dep_url is not None:
                     dep_version = None
+                elif (
+                    backend.provides is not None
+                    and not dependency.get("owner")
+                    and backend.provides(dep_name)
+                ):
+                    # The backend adds it from its own tree; resolving here
+                    # would fetch a same-named registry package
+                    if dep_version and dep_version != "*":
+                        # The pin is discarded; make the substitution visible
+                        _LOGGER.warning(
+                            "Dependency %s pins version %s; using the library "
+                            "bundled with the framework instead",
+                            dep_name,
+                            dep_version,
+                        )
+                    else:
+                        _LOGGER.debug("Skip backend-provided dependency %s", dep_name)
+                    backend.provided_requests.add(dep_name)
+                    continue
                 dep_key = add_spec(dep_name, dep_version, dep_url)
                 node.edges.add(dep_key)
                 worklist.append(dep_key)
@@ -1263,4 +1360,6 @@ def convert_libraries(
     for component in components.values():
         backend.emit(component)
 
+    _reconcile_versionless_skips(skipped_versionless, components, backend)
+
     return [components[key] for key in top_level if key in components]

esphome/platformio/prefetch.py

@@ -922,8 +922,10 @@ def main(argv: list[str]) -> int:
     """Subprocess entry point: ``prefetch <build_dir> <env_name>``."""
     from esphome.core import CORE
     from esphome.log import setup_log
+    from esphome.platformio.runner import patch_registry_private_packages
 
     signal.signal(signal.SIGTERM, _sigterm)
+    patch_registry_private_packages()
     raw_level = os.environ.get("ESPHOME_PREFETCH_LOG_LEVEL")
     try:
         level = int(raw_level) if raw_level is not None else logging.INFO

esphome/platformio/runner.py

@@ -2,7 +2,8 @@
 
 Invoked via ``python -m esphome.platformio.runner`` instead of
 ``python -m platformio`` so that the patches (incremental rebuild
-preservation, download retries) apply inside the subprocess. Running
+preservation, download retries, skipping the private-package probe) apply
+inside the subprocess. Running
 PlatformIO in a subprocess keeps its ``sys.path`` mutations and other
 global state from leaking into the ESPHome process.
 """
@@ -105,6 +106,16 @@ def patch_file_downloader() -> None:
     FileDownloader.__init__ = patched_init
 
 
+def patch_registry_private_packages() -> None:
+    """Skip PlatformIO's private-package probe; it sleeps ~500 ms per lookup.
+
+    ESPHome never uses private packages, so the answer is always False.
+    """
+    from platformio.registry.client import RegistryClient
+
+    RegistryClient.allowed_private_packages = staticmethod(lambda: False)  # type: ignore[method-assign]
+
+
 _IGNORE_LIB_WARNINGS = "(?:Hash|Update)"
 # Regex patterns matched against each line of PlatformIO output. Lines that
 # match are dropped by RedirectText before they reach the parent process.
@@ -152,6 +163,7 @@ FILTER_PLATFORMIO_LINES = [
 def main() -> int:
     patch_structhash()
     patch_file_downloader()
+    patch_registry_private_packages()
 
     # Wrap stdout/stderr with RedirectText before PlatformIO runs:
     #

esphome/yaml_util.py

@@ -1057,11 +1057,19 @@ def _load_yaml_internal_with_type(
         loader.dispose()
 
 
-def dump(dict_, show_secrets=False, sort_keys=False, relative_to: Path | None = None):
+def dump(
+    dict_,
+    show_secrets=False,
+    sort_keys=False,
+    relative_to: Path | None = None,
+    data_dir: Path | None = None,
+):
     """Dump YAML to a string and remove null.
 
     When ``relative_to`` is given, Path values are dumped relative to that
-    directory (POSIX form) so the output is machine independent.
+    directory (POSIX form) so the output is machine independent; Path values
+    under ``data_dir`` are then dumped as ``.esphome/<rest>``. ``data_dir``
+    has no effect unless ``relative_to`` is also given.
     """
     if show_secrets:
         _SECRET_VALUES.clear()
@@ -1073,6 +1081,7 @@ def dump(dict_, show_secrets=False, sort_keys=False, relative_to: Path | None =
     class _Dumper(ESPHomeDumper):
         _redact_sensitive = not show_secrets
         _relative_to = relative_to
+        _data_dir = data_dir
 
     return yaml.dump(
         dict_,
@@ -1231,6 +1240,9 @@ class ESPHomeDumper(yaml.SafeDumper):
     # directory (in POSIX form) so the output does not depend on where the
     # config lives on the machine that produced it.
     _relative_to: Path | None = None
+    # Paths under this directory are dumped as ``.esphome/<rest>`` so the
+    # add-on's ``/data`` mount matches the CLI layout.
+    _data_dir: Path | None = None
 
     def represent_mapping(self, tag, mapping, flow_style=None):
         value = []
@@ -1274,6 +1286,12 @@ class ESPHomeDumper(yaml.SafeDumper):
             # path that still cannot be relativized (e.g. a different drive)
             # keeps its POSIX form so separators stay stable across OSes.
             path = Path(os.path.normpath(value))
+            # Checked first: the default data dir sits inside the config dir.
+            if self._data_dir is not None and path.is_relative_to(
+                data_dir := os.path.normpath(self._data_dir)
+            ):
+                rel = Path(".esphome") / path.relative_to(data_dir)
+                return self.represent_stringify(rel.as_posix())
             with suppress(ValueError):
                 path = path.relative_to(
                     os.path.normpath(self._relative_to), walk_up=True

requirements.txt

@@ -12,7 +12,7 @@ pyserial==3.5
 platformio==6.1.19
 esptool==5.3.1
 click==8.3.3
-aioesphomeapi==46.2.1
+aioesphomeapi==46.3.0
 aiohappyeyeballs==2.7.1  # Happy Eyeballs for requests downloads; already pulled in by aioesphomeapi
 zeroconf==0.150.0
 puremagic==2.2.0
@@ -20,7 +20,7 @@ ruamel.yaml==0.19.1 # dashboard_import
 ruamel.yaml.clib==0.2.15 # dashboard_import
 esphome-glyphsets==0.2.0
 pillow==12.3.0
-resvg-py==0.4.0
+resvg-py==0.5.0
 freetype-py==2.5.1
 jinja2==3.1.6
 bleak==3.0.2

script/clang_tidy_hash.py

@@ -1,13 +1,10 @@
-"""Files that affect clang-tidy results, and a content hash over them.
+"""Files that affect clang-tidy results and the idedata built from them.
 
-``CLANG_TIDY_GLOBAL_FILES`` (plus ``SDKCONFIG_DEFAULTS_PREFIX``) is the single
-source of truth for which files influence clang-tidy output. A change to any of
-them can surface warnings in source files a PR didn't touch, so:
-
-* ``script/determine-jobs.py`` runs a full clang-tidy scan when one changes, and
-* ``calculate_clang_tidy_hash()`` folds them into the idedata cache key used by
-  ``script/helpers.py`` (a content hash, unlike an mtime check, stays correct
-  across git checkouts).
+``CLANG_TIDY_GLOBAL_FILES`` (plus ``SDKCONFIG_DEFAULTS_PREFIX``) lists the files
+that influence clang-tidy output; ``script/determine-jobs.py`` runs a full scan
+when one changes. ``ESP_IDF_INFRA_TRIGGER_*`` lists the native ESP-IDF build
+code. ``idedata_cache_hash()`` folds the right set into the idedata cache key
+used by ``script/helpers.py`` and the CI cache action.
 """
 
 from __future__ import annotations
@@ -31,6 +28,18 @@ CLANG_TIDY_GLOBAL_FILES = (
 # this prefix at the repo root.
 SDKCONFIG_DEFAULTS_PREFIX = "sdkconfig.defaults"
 
+# Native ESP-IDF build infra: determine-jobs forces an esp32 compile when these
+# change, and they feed the clang-tidy idedata cache key.
+ESP_IDF_INFRA_TRIGGER_PATH_PREFIXES = ("esphome/espidf/", "esphome/build_helpers/")
+ESP_IDF_INFRA_TRIGGER_FILES = frozenset(
+    {
+        "esphome/build_gen/espidf.py",
+        "esphome/framework_helpers.py",
+        "esphome/platformio/library.py",
+        "esphome/platformio/extra_script.py",
+    }
+)
+
 
 def read_file_bytes(path: Path) -> bytes:
     """Read bytes from a file."""
@@ -66,3 +75,33 @@ def calculate_clang_tidy_hash(repo_root: Path | None = None) -> str:
         hasher.update(read_file_bytes(path))
 
     return hasher.hexdigest()
+
+
+def calculate_idedata_cache_hash(repo_root: Path | None = None) -> str:
+    """Clang-tidy hash plus the Python that generates the idedata."""
+    repo_root = _ensure_repo_root(repo_root)
+
+    hasher = hashlib.sha256()
+    hasher.update(calculate_clang_tidy_hash(repo_root).encode())
+
+    paths = {repo_root / name for name in ESP_IDF_INFRA_TRIGGER_FILES}
+    for prefix in ESP_IDF_INFRA_TRIGGER_PATH_PREFIXES:
+        # .pyc files appear between the CI key computation and load_idedata's.
+        paths.update(
+            path
+            for path in (repo_root / prefix).rglob("*")
+            if "__pycache__" not in path.parts
+        )
+    for path in sorted(paths):
+        if path.is_file():
+            hasher.update(str(path.relative_to(repo_root)).encode())
+            hasher.update(read_file_bytes(path))
+
+    return hasher.hexdigest()
+
+
+def idedata_cache_hash(environment: str, repo_root: Path | None = None) -> str:
+    """Hash gating the cached idedata of one clang-tidy environment."""
+    if "esp32" in environment:
+        return calculate_idedata_cache_hash(repo_root)
+    return calculate_clang_tidy_hash(repo_root)

script/determine-jobs.py

@@ -58,7 +58,12 @@ from pathlib import Path
 import sys
 from typing import Any
 
-from clang_tidy_hash import CLANG_TIDY_GLOBAL_FILES, SDKCONFIG_DEFAULTS_PREFIX
+from clang_tidy_hash import (
+    CLANG_TIDY_GLOBAL_FILES,
+    ESP_IDF_INFRA_TRIGGER_FILES,
+    ESP_IDF_INFRA_TRIGGER_PATH_PREFIXES,
+    SDKCONFIG_DEFAULTS_PREFIX,
+)
 from helpers import (
     CPP_FILE_EXTENSIONS,
     ESPHOME_TESTS_COMPONENTS_PATH,
@@ -96,6 +101,17 @@ COMPONENT_TEST_BATCH_SIZE = 40
 INTEGRATION_TESTS_SPLIT_THRESHOLD = 10
 INTEGRATION_TESTS_SPLIT_BUCKETS = 3
 
+# platformio and aioesphomeapi (requirements.txt), the pytest stack
+# (requirements_test.txt) and the fixture every session compiles; a change
+# to any runs the full matrix
+INTEGRATION_TESTS_TRIGGER_FILES = frozenset(
+    {
+        "requirements.txt",
+        "requirements_test.txt",
+        "tests/integration/fixtures/cache_init.yaml",
+    }
+)
+
 
 def _split_list(items: list[str], n: int) -> list[list[str]]:
     """Split a list into n roughly-equal contiguous parts (matches script/clang-tidy)."""
@@ -216,12 +232,15 @@ def determine_integration_tests(branch: str | None = None) -> tuple[bool, list[s
     3. Integration test infrastructure files changed
        - conftest.py, types.py, const.py, entity_utils.py, state_utils.py, etc.
 
+    4. A file in INTEGRATION_TESTS_TRIGGER_FILES changed
+       - The dependency pins and the session init fixture affect every test
+
     Returns (run_all=False, [test_files...]) when:
 
-    4. Specific integration test files changed
+    5. Specific integration test files changed
        - Only those specific test files are returned
 
-    5. Components used by integration tests (or their dependencies) changed
+    6. Components used by integration tests (or their dependencies) changed
        - Only test files whose fixtures use the changed components are returned
 
     Args:
@@ -239,6 +258,9 @@ def determine_integration_tests(branch: str | None = None) -> tuple[bool, list[s
         # If any core files changed, run all integration tests
         return (True, [])
 
+    if any(f in INTEGRATION_TESTS_TRIGGER_FILES for f in files):
+        return (True, [])
+
     # If infrastructure Python files changed (conftest, utils, etc.), run all tests
     # Excludes test files (test_*.py), fixtures, and non-Python files (README.md)
     if any(
@@ -524,23 +546,6 @@ def _esp32_platformio_path_or_file_trigger(files: list[str]) -> bool:
     return False
 
 
-# Native-build infra: changes under esphome/espidf/, the shared
-# esphome/build_helpers/ package, or the modules the native ESP-IDF build
-# imports affect every esp32 IDF build (now the default toolchain) but aren't
-# components, so the component matrix wouldn't otherwise force any esp32
-# compile. When they change we fold the `esp32` component into the matrix so
-# the default native-IDF build path is still compiled on an infra-only PR.
-ESP_IDF_INFRA_TRIGGER_PATH_PREFIXES = ("esphome/espidf/", "esphome/build_helpers/")
-ESP_IDF_INFRA_TRIGGER_FILES = frozenset(
-    {
-        "esphome/build_gen/espidf.py",
-        "esphome/framework_helpers.py",
-        "esphome/platformio/library.py",
-        "esphome/platformio/extra_script.py",
-    }
-)
-
-
 def _esp_idf_infra_changed(files: list[str]) -> bool:
     """Whether any changed file is ESP-IDF build/runner infrastructure."""
     for file in files:

script/helpers.py

@@ -809,17 +809,14 @@ def load_idedata(environment: str) -> dict[str, Any]:
     start_time = time.time()
     print(f"Loading IDE data for environment '{environment}'...")
 
-    # Reuse the clang-tidy input hash as the cache key: it already covers every
-    # file baked into the generated idedata (platformio.ini, sdkconfig.defaults,
-    # esphome/idf_component.yml), so this can't drift from that file list. A
-    # content hash -- unlike an mtime comparison -- stays correct across git
-    # checkouts, which don't preserve mtimes.
-    from clang_tidy_hash import calculate_clang_tidy_hash
+    # Content hash of the idedata inputs (data files and the generator code); a
+    # content hash, unlike mtimes, stays correct across git checkouts.
+    from clang_tidy_hash import idedata_cache_hash
 
     temp_idedata = Path(temp_folder) / f"idedata-{environment}.json"
     temp_hash = Path(temp_folder) / f"idedata-{environment}.hash"
 
-    cache_key = calculate_clang_tidy_hash()
+    cache_key = idedata_cache_hash(environment)
     changed = (
         not temp_idedata.is_file()
         or not temp_hash.is_file()

tests/component_tests/api/test_action_metadata.py

@@ -0,0 +1,155 @@
+"""Tests for user-defined action field metadata (description / example)."""
+
+from collections.abc import Callable
+from pathlib import Path
+
+import pytest
+
+from esphome.components.api import (
+    _action_strings,
+    _action_strings_size,
+    _has_action_metadata,
+    _validate_esp8266_action_strings,
+    validate_variable,
+)
+from esphome.config_validation import Invalid
+from esphome.const import PlatformFramework
+from esphome.core import CORE
+from esphome.cpp_generator import safe_exp
+from esphome.helpers import fnv1_hash
+from tests.component_tests.helpers import get_define_value
+from tests.component_tests.types import SetCoreConfigCallable
+
+CONFIG = "tests/component_tests/api/test_action_metadata.yaml"
+CONFIG_ESP8266 = "tests/component_tests/api/test_action_metadata_esp8266.yaml"
+CONFIG_SHORTHAND = "tests/component_tests/api/test_action_metadata_shorthand.yaml"
+
+
+def test_metadata_is_emitted_as_progmem_table(
+    generate_main: Callable[[str | Path], str],
+) -> None:
+    """Every action string is a PROGMEM array referenced from one PROGMEM table."""
+    main_cpp = generate_main(CONFIG)
+
+    assert (
+        'static constexpr char api_action_str0[] PROGMEM = "play_buzzer";' in main_cpp
+    )
+    assert (
+        'static constexpr char api_action_str1[] PROGMEM = "Play an RTTTL melody on the buzzer";'
+        in main_cpp
+    )
+    assert (
+        'static constexpr char api_action_str4[] PROGMEM = "two_short:d=4,o=5,b=100:16e6,16e6";'
+        in main_cpp
+    )
+    assert (
+        "static constexpr const char * api_action0_strings[] PROGMEM = {"
+        "api_action_str0, api_action_str1, api_action_str2, api_action_str3, "
+        "api_action_str4, api_action_str5, nullptr, nullptr};" in main_cpp
+    )
+    # An action without metadata still carries the metadata slots (as nullptr)
+    assert (
+        "static constexpr const char * api_action1_strings[] PROGMEM = {"
+        "api_action_str6, nullptr, api_action_str7, nullptr, nullptr};" in main_cpp
+    )
+    assert f"(api_action0_strings, {safe_exp(fnv1_hash('play_buzzer'))});" in main_cpp
+    assert "USE_API_USER_DEFINED_ACTION_METADATA" in {d.name for d in CORE.defines}
+    assert get_define_value("API_USER_ACTION_STRINGS_SCRATCH_SIZE") is None
+
+
+def test_esp8266_sizes_scratch_buffer_for_largest_action(
+    generate_main: Callable[[str | Path], str],
+) -> None:
+    """ESP8266 gets a scratch buffer define equal to the byte total of the largest action."""
+    generate_main(CONFIG_ESP8266)
+
+    # play_buzzer: name, description, two variable names, one description, one example,
+    # each with a terminator
+    assert get_define_value("API_USER_ACTION_STRINGS_SCRATCH_SIZE") == "117"
+
+
+def test_shorthand_variables_emit_no_metadata(
+    generate_main: Callable[[str | Path], str],
+) -> None:
+    """The name: type shorthand emits a name-only table and no define."""
+    main_cpp = generate_main(CONFIG_SHORTHAND)
+
+    assert (
+        "static constexpr const char * api_action0_strings[] PROGMEM = "
+        "{api_action_str0, api_action_str1};" in main_cpp
+    )
+    assert "USE_API_USER_DEFINED_ACTION_METADATA" not in {d.name for d in CORE.defines}
+
+
+def test_variable_shorthand_normalizes_to_mapping() -> None:
+    """A bare type string validates to the mapping form."""
+    assert validate_variable("string") == {"type": "string"}
+
+
+@pytest.mark.parametrize(
+    "value",
+    [
+        {"description": "no type given"},
+        {"type": "string", "selector": "text"},
+        "stringy",
+        {"type": "stringy"},
+    ],
+)
+def test_variable_rejects_invalid(value: object) -> None:
+    """Missing or unknown type and unknown keys raise in both forms."""
+    with pytest.raises(Invalid):
+        validate_variable(value)
+
+
+def _oversized_action_config() -> dict:
+    return {
+        "actions": [
+            {
+                "action": "big",
+                "description": "x" * 300,
+                "variables": {"a": {"type": "string", "example": "y" * 300}},
+            }
+        ]
+    }
+
+
+def test_esp8266_rejects_actions_over_string_budget(
+    set_core_config: SetCoreConfigCallable,
+) -> None:
+    set_core_config(PlatformFramework.ESP8266_ARDUINO)
+    with pytest.raises(Invalid, match="ESP8266 allows at most 384 bytes"):
+        _validate_esp8266_action_strings(_oversized_action_config())
+
+
+def test_other_platforms_have_no_string_budget(
+    set_core_config: SetCoreConfigCallable,
+) -> None:
+    set_core_config(PlatformFramework.ESP32_IDF)
+    config = _oversized_action_config()
+    assert _validate_esp8266_action_strings(config) is config
+
+
+def test_empty_metadata_is_unset_and_not_counted() -> None:
+    """An empty description or example emits nullptr and takes no scratch space."""
+    conf = {
+        "action": "a",
+        "description": "",
+        "variables": {"b": {"type": "int", "description": "", "example": "ex"}},
+    }
+    strings = _action_strings(conf, has_metadata=True)
+    assert strings == ["a", None, "b", None, "ex"]
+    # Every emitted string counts its terminator: "a" + "b" + "ex"
+    assert _action_strings_size(strings) == 2 + 2 + 3
+
+
+def test_empty_metadata_does_not_enable_the_define() -> None:
+    actions = [
+        {
+            "action": "a",
+            "description": "",
+            "variables": {"b": {"type": "int", "example": ""}},
+        }
+    ]
+    assert not _has_action_metadata(actions)
+    actions[0]["variables"]["b"]["example"] = "1"
+    assert _has_action_metadata(actions)

tests/component_tests/api/test_action_metadata.yaml

@@ -0,0 +1,14 @@
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+
+wifi:
+  ssid: MySSID
+  password: password1
+
+logger:
+
+packages:
+  api: !include test_action_metadata_common.yaml

tests/component_tests/api/test_action_metadata_common.yaml

@@ -0,0 +1,18 @@
+api:
+  actions:
+    - action: play_buzzer
+      description: Play an RTTTL melody on the buzzer
+      variables:
+        song_str:
+          type: string
+          description: RTTTL melody string
+          example: "two_short:d=4,o=5,b=100:16e6,16e6"
+        volume:
+          type: int
+      then:
+        - logger.log: Action Called
+    - action: plain_action
+      variables:
+        value: int
+      then:
+        - logger.log: Action Called

tests/component_tests/api/test_action_metadata_esp8266.yaml

@@ -0,0 +1,14 @@
+esphome:
+  name: test
+
+esp8266:
+  board: d1_mini
+
+wifi:
+  ssid: MySSID
+  password: password1
+
+logger:
+
+packages:
+  api: !include test_action_metadata_common.yaml

tests/component_tests/api/test_action_metadata_shorthand.yaml

@@ -0,0 +1,19 @@
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+
+wifi:
+  ssid: MySSID
+  password: password1
+
+logger:
+
+api:
+  actions:
+    - action: plain_action
+      variables:
+        value: int
+      then:
+        - logger.log: Action Called

tests/component_tests/api/test_homeassistant_action.py

@@ -9,7 +9,7 @@ def test_synchronous_chain_keeps_zero_copy_args(generate_main):
 
     assert (
         "api::UserServiceTrigger<api::enums::SUPPORTS_RESPONSE_NONE, StringRef>"
-        '("zero_copy_args", {"message"})' in main_cpp
+        "(api_action0_strings," in main_cpp
     )
 
 
@@ -22,7 +22,7 @@ def test_response_callback_args_are_owning(generate_main):
 
     assert (
         "api::UserServiceTrigger<api::enums::SUPPORTS_RESPONSE_NONE, std::string>"
-        '("response_args", {"message"})' in main_cpp
+        "(api_action1_strings," in main_cpp
     )
     assert "api::HomeAssistantServiceCallAction<std::string>" in main_cpp
     assert "api::HomeAssistantServiceCallAction<StringRef>" not in main_cpp

tests/component_tests/esp32/config/exclusion_reincludes_espnow.yaml

@@ -0,0 +1,11 @@
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+  framework:
+    type: esp-idf
+
+espnow:
+  channel: 1
+  auto_add_peer: true

tests/component_tests/esp32/config/exclusion_reincludes_internal_temperature.yaml

@@ -0,0 +1,11 @@
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+  framework:
+    type: esp-idf
+
+sensor:
+  - platform: internal_temperature
+    name: Internal Temperature