[esp32] IRAM_ATTR on dispatch, document cold path

Put IRAM_ATTR back on esp_log_format (tiny ~43 byte dispatch function)
to match esp_log_va's IRAM placement and avoid cache miss. Leave the
512-byte formatting function in flash — it's cold on 99.9% of builds
(only runs during early boot and at DEBUG framework log level).

.clang-tidy.hash

@@ -1 +1 @@
-e4b9c4b54e705d3c9400e1cdda8ba0b32634780cfa5f32271832e911bdcafe7e
+8e48e836c6fc196d3da000d46eb09db243b87fe33518a74e49c8e009d756074a

.github/workflows/ci.yml

@@ -106,6 +106,7 @@ jobs:
           script/build_codeowners.py --check
           script/build_language_schema.py --check
           script/generate-esp32-boards.py --check
+          script/generate-rp2040-boards.py --check
 
   pytest:
     name: Run pytest
@@ -170,6 +171,8 @@ jobs:
       - common
     outputs:
       integration-tests: ${{ steps.determine.outputs.integration-tests }}
+      integration-tests-run-all: ${{ steps.determine.outputs.integration-tests-run-all }}
+      integration-test-files: ${{ steps.determine.outputs.integration-test-files }}
       clang-tidy: ${{ steps.determine.outputs.clang-tidy }}
       clang-tidy-mode: ${{ steps.determine.outputs.clang-tidy-mode }}
       python-linters: ${{ steps.determine.outputs.python-linters }}
@@ -210,6 +213,8 @@ jobs:
 
           # Extract individual fields
           echo "integration-tests=$(echo "$output" | jq -r '.integration_tests')" >> $GITHUB_OUTPUT
+          echo "integration-tests-run-all=$(echo "$output" | jq -r '.integration_tests_run_all')" >> $GITHUB_OUTPUT
+          echo "integration-test-files=$(echo "$output" | jq -c '.integration_test_files')" >> $GITHUB_OUTPUT
           echo "clang-tidy=$(echo "$output" | jq -r '.clang_tidy')" >> $GITHUB_OUTPUT
           echo "clang-tidy-mode=$(echo "$output" | jq -r '.clang_tidy_mode')" >> $GITHUB_OUTPUT
           echo "python-linters=$(echo "$output" | jq -r '.python_linters')" >> $GITHUB_OUTPUT
@@ -261,9 +266,20 @@ jobs:
       - name: Register matcher
         run: echo "::add-matcher::.github/workflows/matchers/pytest.json"
       - name: Run integration tests
+        env:
+          INTEGRATION_TEST_FILES: ${{ needs.determine-jobs.outputs.integration-test-files }}
+          INTEGRATION_TESTS_RUN_ALL: ${{ needs.determine-jobs.outputs.integration-tests-run-all }}
         run: |
           . venv/bin/activate
-          pytest -vv --no-cov --tb=native -n auto tests/integration/
+          if [[ "$INTEGRATION_TESTS_RUN_ALL" == "true" ]]; then
+            echo "Running all integration tests"
+            pytest -vv --no-cov --tb=native -n auto tests/integration/
+          else
+            # Parse JSON array into bash array to avoid shell expansion issues
+            mapfile -t test_files < <(echo "$INTEGRATION_TEST_FILES" | jq -r '.[]')
+            echo "Running ${#test_files[@]} specific integration tests"
+            pytest -vv --no-cov --tb=native -n auto "${test_files[@]}"
+          fi
 
   cpp-unit-tests:
     name: Run C++ unit tests
@@ -945,13 +961,13 @@ jobs:
           python-version: ${{ env.DEFAULT_PYTHON }}
           cache-key: ${{ needs.common.outputs.cache-key }}
       - name: Download target analysis JSON
-        uses: actions/download-artifact@70fc10c6e5e1ce46ad2ea6f2b72d43f7d47b13c3 # v8.0.0
+        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
         with:
           name: memory-analysis-target
           path: ./memory-analysis
         continue-on-error: true
       - name: Download PR analysis JSON
-        uses: actions/download-artifact@70fc10c6e5e1ce46ad2ea6f2b72d43f7d47b13c3 # v8.0.0
+        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
         with:
           name: memory-analysis-pr
           path: ./memory-analysis

.github/workflows/codeowner-approved-label-update.yml

@@ -10,6 +10,9 @@ name: Codeowner Approved Label
 on:
   pull_request_target:
     types: [opened, synchronize, reopened, ready_for_review]
+    branches-ignore:
+      - release
+      - beta
 
 permissions:
   issues: write

.github/workflows/codeowner-review-request.yml

@@ -13,6 +13,9 @@ on:
   # Needs to be pull_request_target to get write permissions
   pull_request_target:
     types: [opened, reopened, synchronize, ready_for_review]
+    branches-ignore:
+      - release
+      - beta
 
 permissions:
   pull-requests: write

.github/workflows/pr-title-check.yml

@@ -65,6 +65,18 @@ jobs:
               return;
             }
 
+            // Check for angle brackets not wrapped in backticks.
+            // Astro docs MDX treats bare < as JSX component opening tags.
+            const stripped = title.replace(/`[^`]*`/g, '');
+            if (/[<>]/.test(stripped)) {
+              core.setFailed(
+                'PR title contains `<` or `>` not wrapped in backticks.\n' +
+                'Astro docs MDX interprets bare `<` as JSX components.\n' +
+                'Please wrap angle brackets with backticks, e.g.: [component] Add `<feature>` support'
+              );
+              return;
+            }
+
             // Check title starts with [tag] prefix
             const bracketPattern = /^\[\w+\]/;
             if (!bracketPattern.test(title)) {

.github/workflows/release.yml

@@ -171,7 +171,7 @@ jobs:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Download digests
-        uses: actions/download-artifact@70fc10c6e5e1ce46ad2ea6f2b72d43f7d47b13c3 # v8.0.0
+        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
         with:
           pattern: digests-*
           path: /tmp/digests

.pre-commit-config.yaml

@@ -11,7 +11,7 @@ ci:
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
     # Ruff version.
-    rev: v0.15.5
+    rev: v0.15.6
     hooks:
       # Run the linter.
       - id: ruff

Doxyfile

@@ -48,7 +48,7 @@ PROJECT_NAME           = ESPHome
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 2026.3.0b1
+PROJECT_NUMBER         = 2026.4.0-dev
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a

esphome/analyze_memory/__init__.py

@@ -1,6 +1,6 @@
 """Memory usage analyzer for ESPHome compiled binaries."""
 
-from collections import defaultdict
+from collections import Counter, defaultdict
 from dataclasses import dataclass, field
 import logging
 from pathlib import Path
@@ -40,6 +40,15 @@ _READELF_SECTION_PATTERN = re.compile(
     r"\s*\[\s*\d+\]\s+([\.\w]+)\s+\w+\s+[\da-fA-F]+\s+[\da-fA-F]+\s+([\da-fA-F]+)"
 )
 
+# Regex for extracting call targets from objdump disassembly
+# Matches direct call instructions across architectures:
+#   Xtensa: call0/call4/call8/call12/callx0/callx4/callx8/callx12 <addr> <symbol>
+#   ARM:    bl/blx <addr> <symbol>
+# Captures the mangled symbol name inside angle brackets.
+_CALL_TARGET_PATTERN = re.compile(
+    r"\t(?:call(?:0|4|8|12)|callx(?:0|4|8|12)|blx?)\s+[\da-fA-F]+ <([^>]+)>"
+)
+
 # Component category prefixes
 _COMPONENT_PREFIX_ESPHOME = "[esphome]"
 _COMPONENT_PREFIX_EXTERNAL = "[external]"
@@ -197,6 +206,8 @@ class MemoryAnalyzer:
         self._lib_hash_to_name: dict[str, str] = {}
         # Heuristic category to library redirect: "mdns_lib" -> "[lib]mdns"
         self._heuristic_to_lib: dict[str, str] = {}
+        # Function call counts: mangled_name -> call_count
+        self._function_call_counts: Counter[str] = Counter()
 
     def analyze(self) -> dict[str, ComponentMemory]:
         """Analyze the ELF file and return component memory usage."""
@@ -206,6 +217,7 @@ class MemoryAnalyzer:
         self._categorize_symbols()
         self._analyze_cswtch_symbols()
         self._analyze_sdk_libraries()
+        self._analyze_function_calls()
         return dict(self.components)
 
     def _parse_sections(self) -> None:
@@ -384,8 +396,9 @@ class MemoryAnalyzer:
             return
 
         _LOGGER.info("Demangling %d symbols", len(symbols))
-        self._demangle_cache = batch_demangle(symbols, objdump_path=self.objdump_path)
-        _LOGGER.info("Successfully demangled %d symbols", len(self._demangle_cache))
+        demangled = batch_demangle(symbols, objdump_path=self.objdump_path)
+        self._demangle_cache.update(demangled)
+        _LOGGER.info("Successfully demangled %d symbols", len(demangled))
 
     def _demangle_symbol(self, symbol: str) -> str:
         """Get demangled C++ symbol name from cache."""
@@ -1011,6 +1024,43 @@ class MemoryAnalyzer:
             total_size,
         )
 
+    def _analyze_function_calls(self) -> None:
+        """Count function call sites by parsing disassembly output.
+
+        Parses direct call instructions (call0/call8/bl/blx) from objdump -d
+        to count how many times each function is called. This helps identify
+        inlining candidates — frequently called small functions benefit most
+        from inlining.
+        """
+        result = run_tool(
+            [self.objdump_path, "-d", str(self.elf_path)],
+            timeout=60,
+        )
+        if result is None or result.returncode != 0:
+            _LOGGER.debug("Failed to disassemble ELF for function call analysis")
+            return
+
+        self._function_call_counts = Counter(
+            match.group(1)
+            for line in result.stdout.splitlines()
+            if (match := _CALL_TARGET_PATTERN.search(line))
+        )
+
+        # Demangle any call targets not already in the cache
+        missing = [
+            name
+            for name in self._function_call_counts
+            if name not in self._demangle_cache
+        ]
+        if missing:
+            self._batch_demangle_symbols(missing)
+
+        _LOGGER.debug(
+            "Function call analysis: %d unique targets, %d total calls",
+            len(self._function_call_counts),
+            sum(self._function_call_counts.values()),
+        )
+
     def get_unattributed_ram(self) -> tuple[int, int, int]:
         """Get unattributed RAM sizes (SDK/framework overhead).
 

esphome/analyze_memory/cli.py

@@ -231,6 +231,110 @@ class MemoryAnalyzerCLI(MemoryAnalyzer):
                     lines.append(f"    {size:>6,} B  {sym_name}")
             lines.append("")
 
+    # Number of top called functions to show
+    TOP_CALLS_LIMIT: int = 50
+    # Number of inlining candidates to show
+    INLINE_CANDIDATES_LIMIT: int = 25
+    # Maximum function size in bytes to consider for inlining
+    INLINE_SIZE_THRESHOLD: int = 16
+
+    def _build_symbol_sizes(self) -> dict[str, int]:
+        """Build a size lookup from all component symbols: mangled_name -> size."""
+        return {
+            symbol: size
+            for symbols in self._component_symbols.values()
+            for symbol, _, size, _ in symbols
+        }
+
+    def _format_call_row(
+        self, index: int, mangled: str, count: int, symbol_sizes: dict[str, int]
+    ) -> str:
+        """Format a single row for call frequency tables."""
+        demangled = self._demangle_cache.get(mangled, mangled)
+        if len(demangled) > 80:
+            demangled = f"{demangled[:77]}..."
+        size = symbol_sizes.get(mangled)
+        size_str = f"{size:>5,} B" if size is not None else "      ?"
+        return f"{index:>3}  {count:>5}  {size_str}  {demangled}"
+
+    def _add_call_table_header(self, lines: list[str]) -> None:
+        """Add the header row for call frequency tables."""
+        lines.append(f"{'#':>3}  {'Calls':>5}  {'Size':>7}  Function")
+        lines.append(f"{'---':>3}  {'-----':>5}  {'-------':>7}  {'-' * 60}")
+
+    def _add_function_call_analysis(self, lines: list[str]) -> None:
+        """Add function call frequency analysis section.
+
+        Shows the most frequently called functions by call site count.
+        """
+        self._add_section_header(lines, "Top Called Functions")
+
+        symbol_sizes = self._build_symbol_sizes()
+
+        # Sort by call count descending
+        sorted_calls = sorted(
+            self._function_call_counts.items(), key=lambda x: x[1], reverse=True
+        )
+
+        self._add_call_table_header(lines)
+
+        for i, (mangled, count) in enumerate(sorted_calls[: self.TOP_CALLS_LIMIT]):
+            lines.append(self._format_call_row(i + 1, mangled, count, symbol_sizes))
+
+        total_calls = sum(self._function_call_counts.values())
+        lines.append("")
+        lines.append(
+            f"Total: {len(self._function_call_counts)} unique targets, "
+            f"{total_calls:,} call sites"
+        )
+        lines.append("")
+
+    def _add_inline_candidates(self, lines: list[str]) -> None:
+        """Add inlining candidates section.
+
+        Shows frequently called functions that are small enough to benefit
+        from inlining (< 16 bytes). These are the best candidates for
+        reducing call overhead.
+        """
+        self._add_section_header(
+            lines,
+            f"Inlining Candidates (<{self.INLINE_SIZE_THRESHOLD} B, by call count)",
+        )
+
+        symbol_sizes = self._build_symbol_sizes()
+
+        # Filter to small functions with known size, sort by call count
+        candidates = sorted(
+            (
+                (mangled, count)
+                for mangled, count in self._function_call_counts.items()
+                if mangled in symbol_sizes
+                and symbol_sizes[mangled] < self.INLINE_SIZE_THRESHOLD
+            ),
+            key=lambda x: x[1],
+            reverse=True,
+        )
+
+        if not candidates:
+            lines.append("No candidates found.")
+            lines.append("")
+            return
+
+        self._add_call_table_header(lines)
+
+        for i, (mangled, count) in enumerate(
+            candidates[: self.INLINE_CANDIDATES_LIMIT]
+        ):
+            lines.append(self._format_call_row(i + 1, mangled, count, symbol_sizes))
+
+        lines.append("")
+        lines.append(
+            f"Showing top {min(len(candidates), self.INLINE_CANDIDATES_LIMIT)} "
+            f"of {len(candidates)} functions under "
+            f"{self.INLINE_SIZE_THRESHOLD} B"
+        )
+        lines.append("")
+
     def generate_report(self, detailed: bool = False) -> str:
         """Generate a formatted memory report."""
         components = sorted(
@@ -533,6 +637,11 @@ class MemoryAnalyzerCLI(MemoryAnalyzer):
         if self._cswtch_symbols:
             self._add_cswtch_analysis(lines)
 
+        # Function call frequency analysis
+        if self._function_call_counts:
+            self._add_function_call_analysis(lines)
+            self._add_inline_candidates(lines)
+
         lines.append(
             "Note: This analysis covers symbols in the ELF file. Some runtime allocations may not be included."
         )

esphome/components/adc/adc_sensor.h

@@ -22,7 +22,8 @@ namespace adc {
 
 #ifdef USE_ESP32
 // clang-format off
-#if (ESP_IDF_VERSION_MAJOR == 5 && \
+#if ESP_IDF_VERSION_MAJOR >= 6 || \
+    (ESP_IDF_VERSION_MAJOR == 5 && \
      ((ESP_IDF_VERSION_MINOR == 0 && ESP_IDF_VERSION_PATCH >= 5) || \
       (ESP_IDF_VERSION_MINOR == 1 && ESP_IDF_VERSION_PATCH >= 3) || \
       (ESP_IDF_VERSION_MINOR >= 2)) \

esphome/components/adc/adc_sensor_rp2040.cpp

@@ -8,6 +8,13 @@
 #endif  // CYW43_USES_VSYS_PIN
 #include <hardware/adc.h>
 
+// PICO_VSYS_PIN is defined in pico-sdk board headers (e.g. boards/pico2.h),
+// but the Arduino framework's config_autogen.h includes a generic board header
+// that doesn't define it. Provide the standard value (pin 29) as a fallback.
+#ifndef PICO_VSYS_PIN
+#define PICO_VSYS_PIN 29  // NOLINT(cppcoreguidelines-macro-usage)
+#endif
+
 namespace esphome {
 namespace adc {
 

esphome/components/addressable_light/addressable_light_display.h

@@ -33,7 +33,7 @@ class AddressableLightDisplay : public display::DisplayBuffer {
         // - Save the current effect index.
         this->last_effect_index_ = light_state_->get_current_effect_index();
         // - Disable any current effect.
-        light_state_->make_call().set_effect(0).perform();
+        light_state_->make_call().set_effect(uint32_t{0}).perform();
       }
     }
     enabled_ = enabled;

esphome/components/api/api_connection.h

@@ -14,6 +14,12 @@
 #include "api_server.h"
 #include "esphome/core/application.h"
 #include "esphome/core/component.h"
+#ifdef USE_ESP32_CRASH_HANDLER
+#include "esphome/components/esp32/crash_handler.h"
+#endif
+#ifdef USE_RP2040_CRASH_HANDLER
+#include "esphome/components/rp2040/crash_handler.h"
+#endif
 #include "esphome/core/entity_base.h"
 #include "esphome/core/string_ref.h"
 
@@ -235,6 +241,12 @@ class APIConnection final : public APIServerConnectionBase {
     this->flags_.log_subscription = msg.level;
     if (msg.dump_config)
       App.schedule_dump_config();
+#ifdef USE_ESP32_CRASH_HANDLER
+    esp32::crash_handler_log();
+#endif
+#ifdef USE_RP2040_CRASH_HANDLER
+    rp2040::crash_handler_log();
+#endif
   }
 #ifdef USE_API_HOMEASSISTANT_SERVICES
   void on_subscribe_homeassistant_services_request() override { this->flags_.service_call_subscription = true; }

esphome/components/api/api_frame_helper.h

@@ -134,12 +134,16 @@ class APIFrameHelper {
   //
   // For log messages: Use Nagle to coalesce multiple small log packets into
   // fewer larger packets, reducing WiFi overhead. However, we limit batching
-  // to 3 messages to avoid excessive LWIP buffer pressure on memory-constrained
-  // devices like ESP8266. LWIP's TCP_OVERSIZE option coalesces the data into
-  // shared pbufs, but holding data too long waiting for Nagle's timer causes
-  // buffer exhaustion and dropped messages.
+  // to avoid excessive LWIP buffer pressure on memory-constrained devices.
+  // LWIP's TCP_OVERSIZE option coalesces the data into shared pbufs, but
+  // holding data too long waiting for Nagle's timer causes buffer exhaustion
+  // and dropped messages.
   //
-  // Flow: Log 1 (Nagle on) -> Log 2 (Nagle on) -> Log 3 (NODELAY, flush all)
+  // ESP32 (TCP_SND_BUF=4×MSS+) / RP2040 (8×MSS) / LibreTiny (4×MSS): 4 logs per cycle
+  // ESP8266 (2×MSS): 3 logs per cycle (tightest buffers)
+  //
+  // Flow (ESP32/RP2040/LT): Log 1 (Nagle on) -> Log 2 -> Log 3 -> Log 4 (NODELAY, flush)
+  // Flow (ESP8266):         Log 1 (Nagle on) -> Log 2 -> Log 3 (NODELAY, flush all)
   //
   void set_nodelay_for_message(bool is_log_message) {
     if (!is_log_message) {
@@ -150,7 +154,7 @@ class APIFrameHelper {
       return;
     }
 
-    // Log messages 1-3: state transitions -1 -> 1 -> 2 -> -1 (flush on 3rd)
+    // Log messages: state transitions -1 -> 1 -> ... -> LOG_NAGLE_COUNT -> -1 (flush)
     if (this->nodelay_state_ == NODELAY_ON) {
       this->set_nodelay_raw_(false);
       this->nodelay_state_ = 1;
@@ -255,10 +259,16 @@ class APIFrameHelper {
   uint8_t tx_buf_tail_{0};
   uint8_t tx_buf_count_{0};
   // Nagle batching state for log messages. NODELAY_ON (-1) means NODELAY is enabled
-  // (immediate send). Values 1-2 count log messages in the current Nagle batch.
+  // (immediate send). Values 1..LOG_NAGLE_COUNT count log messages in the current Nagle batch.
   // After LOG_NAGLE_COUNT logs, we switch to NODELAY to flush and reset.
+  // ESP8266 has the tightest TCP send buffer (2×MSS) and needs conservative batching.
+  // ESP32 (4×MSS+), RP2040 (8×MSS), and LibreTiny (4×MSS) can coalesce more.
   static constexpr int8_t NODELAY_ON = -1;
+#ifdef USE_ESP8266
   static constexpr int8_t LOG_NAGLE_COUNT = 2;
+#else
+  static constexpr int8_t LOG_NAGLE_COUNT = 3;
+#endif
   int8_t nodelay_state_{NODELAY_ON};
 
   // Internal helper to set TCP_NODELAY socket option

esphome/components/api/api_frame_helper_noise.cpp

@@ -258,10 +258,13 @@ APIError APINoiseFrameHelper::state_action_() {
     // ignore contents, may be used in future for flags
     // Resize for: existing prologue + 2 size bytes + frame data
     size_t old_size = this->prologue_.size();
-    this->prologue_.resize(old_size + 2 + this->rx_buf_.size());
-    this->prologue_[old_size] = (uint8_t) (this->rx_buf_.size() >> 8);
-    this->prologue_[old_size + 1] = (uint8_t) this->rx_buf_.size();
-    std::memcpy(this->prologue_.data() + old_size + 2, this->rx_buf_.data(), this->rx_buf_.size());
+    size_t rx_size = this->rx_buf_.size();
+    this->prologue_.resize(old_size + 2 + rx_size);
+    this->prologue_[old_size] = (uint8_t) (rx_size >> 8);
+    this->prologue_[old_size + 1] = (uint8_t) rx_size;
+    if (rx_size > 0) {
+      std::memcpy(this->prologue_.data() + old_size + 2, this->rx_buf_.data(), rx_size);
+    }
 
     state_ = State::SERVER_HELLO;
   }

esphome/components/api/api_pb2_dump.cpp

@@ -13,7 +13,7 @@ namespace esphome::api {
 static inline void append_quoted_string(DumpBuffer &out, const StringRef &ref) {
   out.append("'");
   if (!ref.empty()) {
-    out.append(ref.c_str());
+    out.append(ref.c_str(), ref.size());
   }
   out.append("'");
 }

esphome/components/api/client.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import asyncio
 from datetime import datetime
+import importlib
 import logging
 from typing import TYPE_CHECKING, Any
 import warnings
@@ -18,6 +19,7 @@ import contextlib
 
 from esphome.const import CONF_KEY, CONF_PORT, __version__
 from esphome.core import CORE
+from esphome.platformio_api import process_stacktrace
 
 from . import CONF_ENCRYPTION
 
@@ -55,9 +57,19 @@ async def async_run_logs(config: dict[str, Any], addresses: list[str]) -> None:
         addresses=addresses,  # Pass all addresses for automatic retry
     )
     dashboard = CORE.dashboard
+    backtrace_state = False
+
+    # Try platform-specific stacktrace handler first, fall back to generic
+    platform_process_stacktrace = None
+    try:
+        module = importlib.import_module("esphome.components." + CORE.target_platform)
+        platform_process_stacktrace = getattr(module, "process_stacktrace")
+    except (AttributeError, ImportError):
+        pass
 
     def on_log(msg: SubscribeLogsResponse) -> None:
         """Handle a new log message."""
+        nonlocal backtrace_state
         time_ = datetime.now()
         message: bytes = msg.message
         text = message.decode("utf8", "backslashreplace")
@@ -67,6 +79,15 @@ async def async_run_logs(config: dict[str, Any], addresses: list[str]) -> None:
         )
         for parsed_msg in parse_log_message(text, timestamp):
             print(parsed_msg.replace("\033", "\\033") if dashboard else parsed_msg)
+        for raw_line in text.splitlines():
+            if platform_process_stacktrace:
+                backtrace_state = platform_process_stacktrace(
+                    config, raw_line, backtrace_state
+                )
+            else:
+                backtrace_state = process_stacktrace(
+                    config, raw_line, backtrace_state=backtrace_state
+                )
 
     stop = await async_run(cli, on_log, name=name)
     try:

esphome/components/api/proto.h

@@ -602,7 +602,7 @@ class ProtoSize {
   static constexpr uint32_t calc_sint32(uint32_t field_id_size, int32_t value) {
     return value ? field_id_size + varint(encode_zigzag32(value)) : 0;
   }
-  static constexpr uint32_t calc_sint32_force(uint32_t field_id_size, int32_t value) {
+  static constexpr inline uint32_t ESPHOME_ALWAYS_INLINE calc_sint32_force(uint32_t field_id_size, int32_t value) {
     return field_id_size + varint(encode_zigzag32(value));
   }
   static constexpr uint32_t calc_int64(uint32_t field_id_size, int64_t value) {
@@ -614,13 +614,13 @@ class ProtoSize {
   static constexpr uint32_t calc_uint64(uint32_t field_id_size, uint64_t value) {
     return value ? field_id_size + varint(value) : 0;
   }
-  static constexpr uint32_t calc_uint64_force(uint32_t field_id_size, uint64_t value) {
+  static constexpr inline uint32_t ESPHOME_ALWAYS_INLINE calc_uint64_force(uint32_t field_id_size, uint64_t value) {
     return field_id_size + varint(value);
   }
   static constexpr uint32_t calc_length(uint32_t field_id_size, size_t len) {
     return len ? field_id_size + varint(static_cast<uint32_t>(len)) + static_cast<uint32_t>(len) : 0;
   }
-  static constexpr uint32_t calc_length_force(uint32_t field_id_size, size_t len) {
+  static constexpr inline uint32_t ESPHOME_ALWAYS_INLINE calc_length_force(uint32_t field_id_size, size_t len) {
     return field_id_size + varint(static_cast<uint32_t>(len)) + static_cast<uint32_t>(len);
   }
   static constexpr uint32_t calc_sint64(uint32_t field_id_size, int64_t value) {
@@ -638,7 +638,8 @@ class ProtoSize {
   static constexpr uint32_t calc_message(uint32_t field_id_size, uint32_t nested_size) {
     return nested_size ? field_id_size + varint(nested_size) + nested_size : 0;
   }
-  static constexpr uint32_t calc_message_force(uint32_t field_id_size, uint32_t nested_size) {
+  static constexpr inline uint32_t ESPHOME_ALWAYS_INLINE calc_message_force(uint32_t field_id_size,
+                                                                            uint32_t nested_size) {
     return field_id_size + varint(nested_size) + nested_size;
   }
 };

esphome/components/audio/__init__.py

@@ -214,4 +214,4 @@ async def to_code(config):
         cg.add_define("USE_AUDIO_MP3_SUPPORT")
     if data.opus_support:
         cg.add_define("USE_AUDIO_OPUS_SUPPORT")
-        add_idf_component(name="esphome/micro-opus", ref="0.3.4")
+        add_idf_component(name="esphome/micro-opus", ref="0.3.5")

esphome/components/captive_portal/captive_portal.cpp

@@ -61,7 +61,7 @@ void CaptivePortal::handle_wifisave(AsyncWebServerRequest *request) {
   // Defer save to main loop thread to avoid NVS operations from HTTP thread
   this->defer([ssid, psk]() { wifi::global_wifi_component->save_wifi_sta(ssid.c_str(), psk.c_str()); });
 #endif
-  request->redirect(ESPHOME_F("/?save"));
+  request->send(200, ESPHOME_F("text/plain"), ESPHOME_F("Saved. Connecting..."));
 }
 
 void CaptivePortal::setup() {
@@ -71,7 +71,7 @@ void CaptivePortal::setup() {
 void CaptivePortal::start() {
   this->base_->init();
   if (!this->initialized_) {
-    this->base_->add_handler(this);
+    this->base_->add_handler_without_auth(this);
   }
 
   network::IPAddress ip = wifi::global_wifi_component->wifi_soft_ap_ip();

esphome/components/const/__init__.py

@@ -3,6 +3,7 @@
 CODEOWNERS = ["@esphome/core"]
 
 CONF_BYTE_ORDER = "byte_order"
+CONF_CLIMATE_ID = "climate_id"
 BYTE_ORDER_LITTLE = "little_endian"
 BYTE_ORDER_BIG = "big_endian"
 

esphome/components/debug/debug_rp2040.cpp

@@ -1,23 +1,81 @@
 #include "debug_component.h"
 #ifdef USE_RP2040
+#include "esphome/core/defines.h"
 #include "esphome/core/log.h"
 #include <Arduino.h>
+#include <hardware/watchdog.h>
+#if defined(PICO_RP2350)
+#include <hardware/structs/powman.h>
+#else
+#include <hardware/structs/vreg_and_chip_reset.h>
+#endif
+#ifdef USE_RP2040_CRASH_HANDLER
+#include "esphome/components/rp2040/crash_handler.h"
+#endif
 namespace esphome {
 namespace debug {
 
 static const char *const TAG = "debug";
 
-const char *DebugComponent::get_reset_reason_(std::span<char, RESET_REASON_BUFFER_SIZE> buffer) { return ""; }
+const char *DebugComponent::get_reset_reason_(std::span<char, RESET_REASON_BUFFER_SIZE> buffer) {
+  char *buf = buffer.data();
+  const size_t size = RESET_REASON_BUFFER_SIZE;
+  size_t pos = 0;
+
+#if defined(PICO_RP2350)
+  uint32_t chip_reset = powman_hw->chip_reset;
+  if (chip_reset & 0x04000000)  // HAD_GLITCH_DETECT
+    pos = buf_append_str(buf, size, pos, "Power supply glitch|");
+  if (chip_reset & 0x00040000)  // HAD_RUN_LOW
+    pos = buf_append_str(buf, size, pos, "RUN pin|");
+  if (chip_reset & 0x00020000)  // HAD_BOR
+    pos = buf_append_str(buf, size, pos, "Brown-out|");
+  if (chip_reset & 0x00010000)  // HAD_POR
+    pos = buf_append_str(buf, size, pos, "Power-on reset|");
+#else
+  uint32_t chip_reset = vreg_and_chip_reset_hw->chip_reset;
+  if (chip_reset & 0x00010000)  // HAD_RUN
+    pos = buf_append_str(buf, size, pos, "RUN pin|");
+  if (chip_reset & 0x00000100)  // HAD_POR
+    pos = buf_append_str(buf, size, pos, "Power-on reset|");
+#endif
+
+  if (watchdog_caused_reboot()) {
+    bool handled = false;
+#ifdef USE_RP2040_CRASH_HANDLER
+    if (rp2040::crash_handler_has_data()) {
+      pos = buf_append_str(buf, size, pos, "Crash (HardFault)|");
+      handled = true;
+    }
+#endif
+    if (!handled) {
+      if (watchdog_enable_caused_reboot()) {
+        pos = buf_append_str(buf, size, pos, "Watchdog timeout|");
+      } else {
+        pos = buf_append_str(buf, size, pos, "Software reset|");
+      }
+    }
+  }
+
+  // Remove trailing '|'
+  if (pos > 0 && buf[pos - 1] == '|') {
+    buf[pos - 1] = '\0';
+  } else if (pos == 0) {
+    return "Unknown";
+  }
+
+  return buf;
+}
 
 const char *DebugComponent::get_wakeup_cause_(std::span<char, RESET_REASON_BUFFER_SIZE> buffer) { return ""; }
 
-uint32_t DebugComponent::get_free_heap_() { return rp2040.getFreeHeap(); }
+uint32_t DebugComponent::get_free_heap_() { return ::rp2040.getFreeHeap(); }
 
 size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE> buffer, size_t pos) {
   constexpr size_t size = DEVICE_INFO_BUFFER_SIZE;
   char *buf = buffer.data();
 
-  uint32_t cpu_freq = rp2040.f_cpu();
+  uint32_t cpu_freq = ::rp2040.f_cpu();
   ESP_LOGD(TAG, "CPU Frequency: %" PRIu32, cpu_freq);
   pos = buf_append_printf(buf, size, pos, "|CPU Frequency: %" PRIu32, cpu_freq);
 

esphome/components/esp32/__init__.py

@@ -1442,6 +1442,11 @@ async def to_code(config):
     cg.add_build_flag("-DUSE_ESP32")
     cg.add_define("USE_NATIVE_64BIT_TIME")
     cg.add_build_flag("-Wl,-z,noexecstack")
+    # Arduino already wraps esp_panic_handler for its own backtrace handler,
+    # so only add our wrap when using ESP-IDF framework to avoid linker conflicts.
+    if conf[CONF_TYPE] == FRAMEWORK_ESP_IDF:
+        cg.add_build_flag("-Wl,--wrap=esp_panic_handler")
+        cg.add_define("USE_ESP32_CRASH_HANDLER")
     cg.add_define("ESPHOME_BOARD", config[CONF_BOARD])
     variant = config[CONF_VARIANT]
     cg.add_build_flag(f"-DUSE_ESP32_VARIANT_{variant}")
@@ -1609,6 +1614,11 @@ async def to_code(config):
     # This saves ~250 bytes of RAM (tag cache) and associated code
     add_idf_sdkconfig_option("CONFIG_LOG_TAG_LEVEL_IMPL_NONE", True)
 
+    # Use ESP-IDF Log V2 to eliminate per-site esp_log_timestamp() macro expansions
+    # V2 centralizes formatting inside esp_log(), reducing flash usage
+    add_idf_sdkconfig_option("CONFIG_LOG_VERSION_1", False)
+    add_idf_sdkconfig_option("CONFIG_LOG_VERSION_2", True)
+
     # Reduce PHY TX power in the event of a brownout
     add_idf_sdkconfig_option("CONFIG_ESP_PHY_REDUCE_TX_POWER", True)
 

esphome/components/esp32/core.cpp

@@ -1,6 +1,7 @@
 #ifdef USE_ESP32
 
 #include "esphome/core/defines.h"
+#include "crash_handler.h"
 #include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
 #include "preferences.h"
@@ -36,6 +37,11 @@ void arch_restart() {
 }
 
 void arch_init() {
+#ifdef USE_ESP32_CRASH_HANDLER
+  // Read crash data from previous boot before anything else
+  esp32::crash_handler_read_and_clear();
+#endif
+
   // Enable the task watchdog only on the loop task (from which we're currently running)
   esp_task_wdt_add(nullptr);
 

esphome/components/esp32/crash_handler.cpp

@@ -0,0 +1,355 @@
+#ifdef USE_ESP32
+
+#include "esphome/core/defines.h"
+#ifdef USE_ESP32_CRASH_HANDLER
+
+#include "crash_handler.h"
+#include "esphome/core/log.h"
+
+#include <cinttypes>
+#include <cstring>
+#include <esp_attr.h>
+#include <esp_private/panic_internal.h>
+#include <soc/soc.h>
+
+#if CONFIG_IDF_TARGET_ARCH_XTENSA
+#include <esp_cpu_utils.h>
+#include <esp_debug_helpers.h>
+#include <xtensa_context.h>
+#elif CONFIG_IDF_TARGET_ARCH_RISCV
+#include <riscv/rvruntime-frames.h>
+#endif
+
+static constexpr uint32_t CRASH_MAGIC = 0xDEADBEEF;
+static constexpr size_t MAX_BACKTRACE = 16;
+
+// Check if an address looks like code (flash-mapped or IRAM).
+// Must be safe to call from panic context (no flash access needed).
+static inline bool IRAM_ATTR is_code_addr(uint32_t addr) {
+  return (addr >= SOC_IROM_LOW && addr < SOC_IROM_HIGH) || (addr >= SOC_IRAM_LOW && addr < SOC_IRAM_HIGH);
+}
+
+#if CONFIG_IDF_TARGET_ARCH_RISCV
+// Check if a code address is a real return address by verifying the preceding
+// instruction is a JAL or JALR with rd=ra (x1). Called at log time (not during
+// panic) so flash cache is available and both IRAM and IROM are safely readable.
+static inline bool is_return_addr(uint32_t addr) {
+  if (!is_code_addr(addr) || addr < 4)
+    return false;
+  // A return address on the stack points to the instruction after a call.
+  // Check for 4-byte JAL/JALR call instruction before this address.
+  // Use memcpy for alignment safety — RISC-V C extension means code addresses
+  // are only 2-byte aligned, so addr-4 may not be 4-byte aligned.
+  uint32_t inst;
+  memcpy(&inst, (const void *) (addr - 4), sizeof(inst));
+  // RISC-V instruction encoding: bits [6:0] = opcode, bits [11:7] = rd
+  uint32_t opcode = inst & 0x7f;  // Extract 7-bit opcode
+  uint32_t rd = inst & 0xf80;     // Extract rd field (bits 11:7)
+  // Match JAL (0x6f) or JALR (0x67) with rd=ra (x1, encoded as 0x80 = 1<<7)
+  if ((opcode == 0x6f || opcode == 0x67) && rd == 0x80)
+    return true;
+  // Check for 2-byte compressed c.jalr before this address (C extension).
+  // c.jalr saves to ra implicitly: funct4=1001, rs1!=0, rs2=0, op=10
+  if (addr >= 2) {
+    uint16_t c_inst = *(uint16_t *) (addr - 2);
+    if ((c_inst & 0xf07f) == 0x9002 && (c_inst & 0x0f80) != 0)
+      return true;
+  }
+  return false;
+}
+#endif
+
+// Raw crash data written by the panic handler wrapper.
+// Lives in .noinit so it survives software reset but contains garbage after power cycle.
+// Validated by magic marker. Static linkage since it's only used within this file.
+// Version field is first so future firmware can always identify the struct layout.
+// Magic is second to validate the data. Remaining fields can change between versions.
+// Version is uint32_t because it would be padded to 4 bytes anyway before the next
+// uint32_t field, so we use the full width rather than wasting 3 bytes of padding.
+static constexpr uint32_t CRASH_DATA_VERSION = 1;
+struct RawCrashData {
+  uint32_t version;
+  uint32_t magic;
+  uint32_t pc;
+  uint8_t backtrace_count;
+  uint8_t reg_frame_count;  // Number of entries from registers (not stack-scanned)
+  uint8_t exception;        // panic_exception_t enum (FAULT/ABORT/IWDT/TWDT/DEBUG)
+  uint8_t pseudo_excause;   // Whether cause is a pseudo exception (Xtensa SoC-level panic)
+  uint32_t backtrace[MAX_BACKTRACE];
+  uint32_t cause;  // Architecture-specific: exccause (Xtensa) or mcause (RISC-V)
+};
+static RawCrashData __attribute__((section(".noinit")))
+s_raw_crash_data;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+
+// Whether crash data was found and validated this boot.
+static bool s_crash_data_valid = false;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+
+namespace esphome::esp32 {
+
+static const char *const TAG = "esp32.crash";
+
+void crash_handler_read_and_clear() {
+  if (s_raw_crash_data.magic == CRASH_MAGIC && s_raw_crash_data.version == CRASH_DATA_VERSION) {
+    s_crash_data_valid = true;
+    // Clamp counts to prevent out-of-bounds reads from corrupt .noinit data
+    if (s_raw_crash_data.backtrace_count > MAX_BACKTRACE)
+      s_raw_crash_data.backtrace_count = MAX_BACKTRACE;
+    if (s_raw_crash_data.reg_frame_count > s_raw_crash_data.backtrace_count)
+      s_raw_crash_data.reg_frame_count = s_raw_crash_data.backtrace_count;
+    if (s_raw_crash_data.exception > 4)  // panic_exception_t max value
+      s_raw_crash_data.exception = 4;    // Default to PANIC_EXCEPTION_FAULT
+    if (s_raw_crash_data.pseudo_excause > 1)
+      s_raw_crash_data.pseudo_excause = 0;
+  }
+  // Clear magic regardless so we don't re-report on next normal reboot
+  s_raw_crash_data.magic = 0;
+}
+
+bool crash_handler_has_data() { return s_crash_data_valid; }
+
+// Look up the exception cause as a human-readable string.
+// Tables mirror ESP-IDF's panic_arch_fill_info() which uses local static arrays
+// not exposed via any public API.
+static const char *get_exception_reason() {
+#if CONFIG_IDF_TARGET_ARCH_XTENSA
+  if (s_raw_crash_data.pseudo_excause) {
+    // SoC-level panic: watchdog, cache error, etc.
+    // Keep in sync with ESP-IDF's PANIC_RSN_* defines
+    static const char *const PSEUDO_REASON[] = {
+        "Unknown reason",                 // 0
+        "Unhandled debug exception",      // 1
+        "Double exception",               // 2
+        "Unhandled kernel exception",     // 3
+        "Coprocessor exception",          // 4
+        "Interrupt wdt timeout on CPU0",  // 5
+        "Interrupt wdt timeout on CPU1",  // 6
+        "Cache error",                    // 7
+    };
+    uint32_t cause = s_raw_crash_data.cause;
+    if (cause < sizeof(PSEUDO_REASON) / sizeof(PSEUDO_REASON[0]))
+      return PSEUDO_REASON[cause];
+    return PSEUDO_REASON[0];
+  }
+  // Real Xtensa exception
+  static const char *const REASON[] = {
+      "IllegalInstruction",
+      "Syscall",
+      "InstructionFetchError",
+      "LoadStoreError",
+      "Level1Interrupt",
+      "Alloca",
+      "IntegerDivideByZero",
+      "PCValue",
+      "Privileged",
+      "LoadStoreAlignment",
+      nullptr,
+      nullptr,
+      "InstrPDAddrError",
+      "LoadStorePIFDataError",
+      "InstrPIFAddrError",
+      "LoadStorePIFAddrError",
+      "InstTLBMiss",
+      "InstTLBMultiHit",
+      "InstFetchPrivilege",
+      nullptr,
+      "InstrFetchProhibited",
+      nullptr,
+      nullptr,
+      nullptr,
+      "LoadStoreTLBMiss",
+      "LoadStoreTLBMultihit",
+      "LoadStorePrivilege",
+      nullptr,
+      "LoadProhibited",
+      "StoreProhibited",
+  };
+  uint32_t cause = s_raw_crash_data.cause;
+  if (cause < sizeof(REASON) / sizeof(REASON[0]) && REASON[cause] != nullptr)
+    return REASON[cause];
+#elif CONFIG_IDF_TARGET_ARCH_RISCV
+  // For SoC-level panics (watchdog, cache error), mcause holds IDF-internal
+  // interrupt numbers, not standard RISC-V cause codes. The exception type
+  // field already identifies these, so just return null to use the type name.
+  if (s_raw_crash_data.pseudo_excause)
+    return nullptr;
+  static const char *const REASON[] = {
+      "Instruction address misaligned",
+      "Instruction access fault",
+      "Illegal instruction",
+      "Breakpoint",
+      "Load address misaligned",
+      "Load access fault",
+      "Store address misaligned",
+      "Store access fault",
+      "Environment call from U-mode",
+      "Environment call from S-mode",
+      nullptr,
+      "Environment call from M-mode",
+      "Instruction page fault",
+      "Load page fault",
+      nullptr,
+      "Store page fault",
+  };
+  uint32_t cause = s_raw_crash_data.cause;
+  if (cause < sizeof(REASON) / sizeof(REASON[0]) && REASON[cause] != nullptr)
+    return REASON[cause];
+#endif
+  return "Unknown";
+}
+
+// Exception type names matching panic_exception_t enum
+static const char *get_exception_type() {
+  static const char *const TYPES[] = {
+      "Debug exception",  // PANIC_EXCEPTION_DEBUG
+      "Interrupt wdt",    // PANIC_EXCEPTION_IWDT
+      "Task wdt",         // PANIC_EXCEPTION_TWDT
+      "Abort",            // PANIC_EXCEPTION_ABORT
+      "Fault",            // PANIC_EXCEPTION_FAULT
+  };
+  uint8_t exc = s_raw_crash_data.exception;
+  if (exc < sizeof(TYPES) / sizeof(TYPES[0]))
+    return TYPES[exc];
+  return "Unknown";
+}
+
+// Intentionally uses separate ESP_LOGE calls per line instead of combining into
+// one multi-line log message. This ensures each address appears as its own line
+// on the serial console, making it possible to see partial output if the device
+// crashes again during boot, and allowing the CLI's process_stacktrace to match
+// and decode each address individually.
+void crash_handler_log() {
+  if (!s_crash_data_valid)
+    return;
+
+  ESP_LOGE(TAG, "*** CRASH DETECTED ON PREVIOUS BOOT ***");
+  const char *reason = get_exception_reason();
+  if (reason != nullptr) {
+    ESP_LOGE(TAG, "  Reason: %s - %s", get_exception_type(), reason);
+  } else {
+    ESP_LOGE(TAG, "  Reason: %s", get_exception_type());
+  }
+  ESP_LOGE(TAG, "  PC:  0x%08" PRIX32 "  (fault location)", s_raw_crash_data.pc);
+  uint8_t bt_num = 0;
+  for (uint8_t i = 0; i < s_raw_crash_data.backtrace_count; i++) {
+    uint32_t addr = s_raw_crash_data.backtrace[i];
+#if CONFIG_IDF_TARGET_ARCH_RISCV
+    // Register-sourced entries (MEPC/RA) are trusted; only filter stack-scanned ones.
+    if (i >= s_raw_crash_data.reg_frame_count && !is_return_addr(addr))
+      continue;
+#endif
+#if CONFIG_IDF_TARGET_ARCH_RISCV
+    const char *source = (i < s_raw_crash_data.reg_frame_count) ? "backtrace" : "stack scan";
+#else
+    const char *source = "backtrace";
+#endif
+    ESP_LOGE(TAG, "  BT%d: 0x%08" PRIX32 "  (%s)", bt_num++, addr, source);
+  }
+  // Build addr2line hint with all captured addresses for easy copy-paste
+  char hint[256];
+  int pos = snprintf(hint, sizeof(hint), "Use: addr2line -pfiaC -e firmware.elf 0x%08" PRIX32, s_raw_crash_data.pc);
+  for (uint8_t i = 0; i < s_raw_crash_data.backtrace_count && pos < (int) sizeof(hint) - 12; i++) {
+    uint32_t addr = s_raw_crash_data.backtrace[i];
+#if CONFIG_IDF_TARGET_ARCH_RISCV
+    if (i >= s_raw_crash_data.reg_frame_count && !is_return_addr(addr))
+      continue;
+#endif
+    pos += snprintf(hint + pos, sizeof(hint) - pos, " 0x%08" PRIX32, addr);
+  }
+  ESP_LOGE(TAG, "%s", hint);
+}
+
+}  // namespace esphome::esp32
+
+// --- Panic handler wrapper ---
+// Intercepts esp_panic_handler() via --wrap linker flag to capture crash data
+// into NOINIT memory before the normal panic handler runs.
+//
+extern "C" {
+// NOLINTBEGIN(bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp,readability-identifier-naming)
+// Names are mandated by the --wrap linker mechanism
+extern void __real_esp_panic_handler(panic_info_t *info);
+
+void IRAM_ATTR __wrap_esp_panic_handler(panic_info_t *info) {
+  // Save the faulting PC and exception info
+  s_raw_crash_data.pc = (uint32_t) info->addr;
+  s_raw_crash_data.backtrace_count = 0;
+  s_raw_crash_data.reg_frame_count = 0;
+  s_raw_crash_data.exception = (uint8_t) info->exception;
+  s_raw_crash_data.pseudo_excause = info->pseudo_excause ? 1 : 0;
+
+#if CONFIG_IDF_TARGET_ARCH_XTENSA
+  // Xtensa: walk the backtrace using the public API
+  if (info->frame != nullptr) {
+    auto *xt_frame = (XtExcFrame *) info->frame;
+    s_raw_crash_data.cause = xt_frame->exccause;
+    esp_backtrace_frame_t bt_frame = {
+        .pc = (uint32_t) xt_frame->pc,
+        .sp = (uint32_t) xt_frame->a1,
+        .next_pc = (uint32_t) xt_frame->a0,
+        .exc_frame = xt_frame,
+    };
+
+    uint8_t count = 0;
+    // First frame PC
+    uint32_t first_pc = esp_cpu_process_stack_pc(bt_frame.pc);
+    if (is_code_addr(first_pc)) {
+      s_raw_crash_data.backtrace[count++] = first_pc;
+    }
+    // Walk remaining frames
+    while (count < MAX_BACKTRACE && bt_frame.next_pc != 0) {
+      if (!esp_backtrace_get_next_frame(&bt_frame)) {
+        break;
+      }
+      uint32_t pc = esp_cpu_process_stack_pc(bt_frame.pc);
+      if (is_code_addr(pc)) {
+        s_raw_crash_data.backtrace[count++] = pc;
+      }
+    }
+    s_raw_crash_data.backtrace_count = count;
+  }
+
+#elif CONFIG_IDF_TARGET_ARCH_RISCV
+  // RISC-V: capture MEPC + RA, then scan stack for code addresses
+  if (info->frame != nullptr) {
+    auto *rv_frame = (RvExcFrame *) info->frame;
+    s_raw_crash_data.cause = rv_frame->mcause;
+    uint8_t count = 0;
+
+    // Save MEPC (fault PC) and RA (return address)
+    if (is_code_addr(rv_frame->mepc)) {
+      s_raw_crash_data.backtrace[count++] = rv_frame->mepc;
+    }
+    if (is_code_addr(rv_frame->ra) && rv_frame->ra != rv_frame->mepc) {
+      s_raw_crash_data.backtrace[count++] = rv_frame->ra;
+    }
+
+    // Track how many entries came from registers (MEPC/RA) so we can
+    // skip return-address validation for them at log time.
+    s_raw_crash_data.reg_frame_count = count;
+
+    // Scan stack for code addresses — captures broadly during panic,
+    // filtered by is_return_addr() at log time when flash is accessible.
+    auto *scan_start = (uint32_t *) rv_frame->sp;
+    for (uint32_t i = 0; i < 64 && count < MAX_BACKTRACE; i++) {
+      uint32_t val = scan_start[i];
+      if (is_code_addr(val) && val != rv_frame->mepc && val != rv_frame->ra) {
+        s_raw_crash_data.backtrace[count++] = val;
+      }
+    }
+    s_raw_crash_data.backtrace_count = count;
+  }
+#endif
+
+  // Write version and magic last — ensures all data is written before we mark it valid
+  s_raw_crash_data.version = CRASH_DATA_VERSION;
+  s_raw_crash_data.magic = CRASH_MAGIC;
+
+  // Call the real panic handler (prints to UART, does core dump, reboots, etc.)
+  __real_esp_panic_handler(info);
+}
+
+// NOLINTEND(bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp,readability-identifier-naming)
+}  // extern "C"
+
+#endif  // USE_ESP32_CRASH_HANDLER
+#endif  // USE_ESP32

esphome/components/esp32/crash_handler.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#ifdef USE_ESP32_CRASH_HANDLER
+
+namespace esphome::esp32 {
+
+/// Read crash data from NOINIT memory and clear the magic marker.
+void crash_handler_read_and_clear();
+
+/// Log crash data if a crash was detected on previous boot.
+void crash_handler_log();
+
+/// Returns true if crash data was found this boot.
+bool crash_handler_has_data();
+
+}  // namespace esphome::esp32
+
+#endif  // USE_ESP32_CRASH_HANDLER

esphome/components/esp32_ble_client/ble_client_base.cpp

@@ -27,6 +27,7 @@ static constexpr uint16_t MEDIUM_CONN_TIMEOUT = 800;  // 800 * 10ms = 8s
 static constexpr uint16_t FAST_MIN_CONN_INTERVAL = 0x06;  // 6 * 1.25ms = 7.5ms (BLE minimum)
 static constexpr uint16_t FAST_MAX_CONN_INTERVAL = 0x06;  // 6 * 1.25ms = 7.5ms
 static constexpr uint16_t FAST_CONN_TIMEOUT = 1000;       // 1000 * 10ms = 10s
+static constexpr uint32_t DISCONNECTING_TIMEOUT = 10000;  // 10s
 static const esp_bt_uuid_t NOTIFY_DESC_UUID = {
     .len = ESP_UUID_LEN_16,
     .uuid =
@@ -62,6 +63,15 @@ void BLEClientBase::loop() {
   // will enable it again when a connection is needed.
   else if (this->state() == espbt::ClientState::IDLE) {
     this->disable_loop();
+  } else if (this->state() == espbt::ClientState::DISCONNECTING &&
+             (millis() - this->disconnecting_started_) > DISCONNECTING_TIMEOUT) {
+    ESP_LOGE(TAG, "[%d] [%s] Timeout waiting for CLOSE_EVT after disconnect, forcing IDLE", this->connection_index_,
+             this->address_str_);
+    // release_services() must be called before set_idle_() — if we entered DISCONNECTING
+    // via unconditional_disconnect() (which doesn't call release_services()), and ESP-IDF
+    // never delivered CLOSE_EVT/DISCONNECT_EVT, services would leak without this call.
+    this->release_services();
+    this->set_idle_();
   }
 }
 
@@ -101,12 +111,16 @@ bool BLEClientBase::parse_device(const espbt::ESPBTDevice &device) {
 #endif
 
 void BLEClientBase::connect() {
-  // Prevent duplicate connection attempts
+  // Prevent duplicate connection attempts or connecting while still disconnecting
   if (this->state() == espbt::ClientState::CONNECTING || this->state() == espbt::ClientState::CONNECTED ||
       this->state() == espbt::ClientState::ESTABLISHED) {
     ESP_LOGW(TAG, "[%d] [%s] Connection already in progress, state=%s", this->connection_index_, this->address_str_,
              espbt::client_state_to_string(this->state()));
     return;
+  } else if (this->state() == espbt::ClientState::DISCONNECTING) {
+    ESP_LOGW(TAG, "[%d] [%s] Cannot connect, still waiting for CLOSE_EVT to complete disconnect",
+             this->connection_index_, this->address_str_);
+    return;
   }
   ESP_LOGI(TAG, "[%d] [%s] 0x%02x Connecting", this->connection_index_, this->address_str_, this->remote_addr_type_);
   this->paired_ = false;
@@ -174,7 +188,7 @@ void BLEClientBase::unconditional_disconnect() {
     this->set_address(0);
     this->set_state(espbt::ClientState::IDLE);
   } else {
-    this->set_state(espbt::ClientState::DISCONNECTING);
+    this->set_disconnecting_();
   }
 }
 
@@ -220,6 +234,7 @@ void BLEClientBase::log_connection_params_(const char *param_type) {
 void BLEClientBase::handle_connection_result_(esp_err_t ret) {
   if (ret) {
     this->log_gattc_warning_("esp_ble_gattc_open", ret);
+    // Don't use set_idle_() here — CONNECT_EVT never fired so conn_id_ is still UNSET_CONN_ID.
     this->set_state(espbt::ClientState::IDLE);
   }
 }
@@ -311,15 +326,16 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
       }
       if (param->open.status != ESP_GATT_OK && param->open.status != ESP_GATT_ALREADY_OPEN) {
         this->log_gattc_warning_("Connection open", param->open.status);
-        this->set_state(espbt::ClientState::IDLE);
+        // Connection was never established so CLOSE_EVT may not follow
+        this->set_idle_();
         break;
       }
       if (this->want_disconnect_) {
         // Disconnect was requested after connecting started,
         // but before the connection was established. Now that we have
         // this->conn_id_ set, we can disconnect it.
+        // Don't reset conn_id_ here — CLOSE_EVT needs it to match and call set_idle_().
         this->unconditional_disconnect();
-        this->conn_id_ = UNSET_CONN_ID;
         break;
       }
       // MTU negotiation already started in ESP_GATTC_CONNECT_EVT
@@ -363,8 +379,22 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
         ESP_LOGD(TAG, "[%d] [%s] ESP_GATTC_DISCONNECT_EVT, reason 0x%02x", this->connection_index_, this->address_str_,
                  param->disconnect.reason);
       }
+      // For active disconnects (esp_ble_gattc_close), CLOSE_EVT arrives before
+      // DISCONNECT_EVT. If CLOSE_EVT already transitioned us to IDLE, don't go
+      // backwards to DISCONNECTING — the connection is already fully cleaned up.
+      if (this->state() == espbt::ClientState::IDLE) {
+        this->log_event_("DISCONNECT_EVT after CLOSE_EVT, already IDLE");
+        break;
+      }
+      // For passive disconnects (remote device disconnected or link lost),
+      // DISCONNECT_EVT arrives first. Don't transition to IDLE yet — wait for
+      // CLOSE_EVT to ensure the controller has fully freed resources (L2CAP
+      // channels, ATT resources, HCI connection handle). Transitioning to IDLE
+      // here would allow reconnection before cleanup is complete, causing the
+      // controller to reject the new connection (status=133) or crash with
+      // ASSERT_PARAM in lld_evt.c.
       this->release_services();
-      this->set_state(espbt::ClientState::IDLE);
+      this->set_disconnecting_();
       break;
     }
 
@@ -387,8 +417,7 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
         return false;
       this->log_gattc_lifecycle_event_("CLOSE");
       this->release_services();
-      this->set_state(espbt::ClientState::IDLE);
-      this->conn_id_ = UNSET_CONN_ID;
+      this->set_idle_();
       break;
     }
     case ESP_GATTC_SEARCH_RES_EVT: {

esphome/components/esp32_ble_client/ble_client_base.h

@@ -113,11 +113,14 @@ class BLEClientBase : public espbt::ESPBTClient, public Component {
   char address_str_[MAC_ADDRESS_PRETTY_BUFFER_SIZE]{};
   esp_bd_addr_t remote_bda_;  // 6 bytes
 
-  // Group 5: 2-byte types
+  // Group 5: 4-byte types
+  uint32_t disconnecting_started_{0};
+
+  // Group 6: 2-byte types
   uint16_t conn_id_{UNSET_CONN_ID};
   uint16_t mtu_{23};
 
-  // Group 6: 1-byte types and small enums
+  // Group 7: 1-byte types and small enums
   esp_ble_addr_type_t remote_addr_type_{BLE_ADDR_TYPE_PUBLIC};
   espbt::ConnectionType connection_type_{espbt::ConnectionType::V1};
   uint8_t connection_index_;
@@ -137,6 +140,16 @@ class BLEClientBase : public espbt::ESPBTClient, public Component {
   void log_gattc_warning_(const char *operation, esp_err_t err);
   void log_connection_params_(const char *param_type);
   void handle_connection_result_(esp_err_t ret);
+  /// Transition to IDLE and reset conn_id — call when the connection is fully dead.
+  void set_idle_() {
+    this->set_state(espbt::ClientState::IDLE);
+    this->conn_id_ = UNSET_CONN_ID;
+  }
+  /// Transition to DISCONNECTING and start the safety timeout.
+  void set_disconnecting_() {
+    this->disconnecting_started_ = millis();
+    this->set_state(espbt::ClientState::DISCONNECTING);
+  }
   // Compact error logging helpers to reduce flash usage
   void log_error_(const char *message);
   void log_error_(const char *message, int code);

esphome/components/esp32_hosted/__init__.py

@@ -105,7 +105,7 @@ async def to_code(config):
     if framework_ver >= cv.Version(5, 5, 0):
         esp32.add_idf_component(name="espressif/esp_wifi_remote", ref="1.4.0")
         esp32.add_idf_component(name="espressif/eppp_link", ref="1.1.4")
-        esp32.add_idf_component(name="espressif/esp_hosted", ref="2.12.0")
+        esp32.add_idf_component(name="espressif/esp_hosted", ref="2.12.1")
     else:
         esp32.add_idf_component(name="espressif/esp_wifi_remote", ref="0.13.0")
         esp32.add_idf_component(name="espressif/eppp_link", ref="0.2.0")

esphome/components/esp32_rmt_led_strip/led_strip.cpp

@@ -99,8 +99,6 @@ void ESP32RMTLEDStripLightOutput::setup() {
   channel.gpio_num = gpio_num_t(this->pin_);
   channel.mem_block_symbols = this->rmt_symbols_;
   channel.trans_queue_depth = 1;
-  channel.flags.io_loop_back = 0;
-  channel.flags.io_od_mode = 0;
   channel.flags.invert_out = this->invert_out_;
   channel.flags.with_dma = this->use_dma_;
   channel.intr_priority = 0;

esphome/components/esphome/ota/ota_esphome.cpp

@@ -18,6 +18,7 @@
 
 #include <cerrno>
 #include <cstdio>
+#include <sys/time.h>
 
 namespace esphome {
 
@@ -238,6 +239,31 @@ void ESPHomeOTAComponent::handle_data_() {
   /// and reboots on success.
   ///
   /// Authentication has already been handled in the non-blocking states AUTH_SEND/AUTH_READ.
+  ///
+  /// Socket I/O strategy:
+  ///
+  /// Before this function, the handshake states use non-blocking I/O:
+  ///   read()/write() return immediately with EWOULDBLOCK if no data
+  ///   loop() retries on next iteration (~16ms), no delay needed
+  ///
+  /// This function switches to blocking mode with SO_RCVTIMEO/SO_SNDTIMEO:
+  ///
+  ///   Path          | Wait mechanism         | WDT strategy
+  ///   --------------|------------------------|---------------------------
+  ///   Main read     | SO_RCVTIMEO (2s block) | feed_wdt() only, no delay
+  ///   readall_()    | SO_RCVTIMEO (2s block) | feed_wdt() + delay(0)
+  ///   writeall_()   | SO_SNDTIMEO (2s block) | feed_wdt() + delay(1)
+  ///
+  /// readall_() uses delay(0) because SO_RCVTIMEO already waited — just yield.
+  /// writeall_() uses delay(1) because on raw TCP (ESP8266, RP2040) writes
+  /// never block (tcp_write returns immediately), so delay(1) prevents spinning.
+  ///
+  /// Platform details:
+  ///   BSD sockets (ESP32):     setblocking(true) makes read/write block
+  ///   lwip sockets (LT):      setblocking(true) makes read/write block
+  ///   Raw TCP (8266, RP2040):  setblocking is no-op; SO_RCVTIMEO uses
+  ///                            socket_delay()/socket_wake() in read();
+  ///                            write() always returns immediately
   ota::OTAResponseTypes error_code = ota::OTA_RESPONSE_ERROR_UNKNOWN;
   bool update_started = false;
   size_t total = 0;
@@ -249,6 +275,14 @@ void ESPHomeOTAComponent::handle_data_() {
   size_t size_acknowledged = 0;
 #endif
 
+  // Set socket timeouts and blocking mode (see strategy table above)
+  struct timeval tv;
+  tv.tv_sec = 2;
+  tv.tv_usec = 0;
+  this->client_->setsockopt(SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
+  this->client_->setsockopt(SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
+  this->client_->setblocking(true);
+
   // Acknowledge auth OK - 1 byte
   this->write_byte_(ota::OTA_RESPONSE_AUTH_OK);
 
@@ -299,7 +333,8 @@ void ESPHomeOTAComponent::handle_data_() {
     ssize_t read = this->client_->read(buf, requested);
     if (read == -1) {
       if (this->would_block_(errno)) {
-        this->yield_and_feed_watchdog_();
+        // read() already waited up to SO_RCVTIMEO for data, just feed WDT
+        App.feed_wdt();
         continue;
       }
       ESP_LOGW(TAG, "Read err %d", errno);
@@ -401,7 +436,9 @@ bool ESPHomeOTAComponent::readall_(uint8_t *buf, size_t len) {
     } else {
       at += read;
     }
-    this->yield_and_feed_watchdog_();
+    // read() already waited via SO_RCVTIMEO, just yield without 1ms stall
+    App.feed_wdt();
+    delay(0);
   }
 
   return true;
@@ -422,10 +459,13 @@ bool ESPHomeOTAComponent::writeall_(const uint8_t *buf, size_t len) {
         ESP_LOGW(TAG, "Write err %zu bytes, errno %d", len, errno);
         return false;
       }
+      // EWOULDBLOCK: on raw TCP writes never block, delay(1) prevents spinning
+      this->yield_and_feed_watchdog_();
     } else {
       at += written;
+      // write() may block up to SO_SNDTIMEO on BSD/lwip sockets, feed WDT
+      App.feed_wdt();
     }
-    this->yield_and_feed_watchdog_();
   }
   return true;
 }

esphome/components/ethernet/ethernet_component.cpp

@@ -21,22 +21,6 @@
 
 namespace esphome::ethernet {
 
-#if ESP_IDF_VERSION < ESP_IDF_VERSION_VAL(5, 4, 2)
-// work around IDF compile issue on P4 https://github.com/espressif/esp-idf/pull/15637
-#ifdef USE_ESP32_VARIANT_ESP32P4
-#undef ETH_ESP32_EMAC_DEFAULT_CONFIG
-#define ETH_ESP32_EMAC_DEFAULT_CONFIG() \
-  { \
-    .smi_gpio = {.mdc_num = 31, .mdio_num = 52}, .interface = EMAC_DATA_INTERFACE_RMII, \
-    .clock_config = {.rmii = {.clock_mode = EMAC_CLK_EXT_IN, .clock_gpio = (emac_rmii_clock_gpio_t) 50}}, \
-    .dma_burst_len = ETH_DMA_BURST_LEN_32, .intr_priority = 0, \
-    .emac_dataif_gpio = \
-        {.rmii = {.tx_en_num = 49, .txd0_num = 34, .txd1_num = 35, .crs_dv_num = 28, .rxd0_num = 29, .rxd1_num = 30}}, \
-    .clock_config_out_in = {.rmii = {.clock_mode = EMAC_CLK_EXT_IN, .clock_gpio = (emac_rmii_clock_gpio_t) -1}}, \
-  }
-#endif
-#endif
-
 static const char *const TAG = "ethernet";
 
 // PHY register size for hex logging
@@ -162,7 +146,7 @@ void EthernetComponent::setup() {
   phy_config.phy_addr = this->phy_addr_;
   phy_config.reset_gpio_num = this->power_pin_;
 
-  eth_esp32_emac_config_t esp32_emac_config = ETH_ESP32_EMAC_DEFAULT_CONFIG();
+  eth_esp32_emac_config_t esp32_emac_config = eth_esp32_emac_default_config();
 #if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 3, 0)
   esp32_emac_config.smi_gpio.mdc_num = this->mdc_pin_;
   esp32_emac_config.smi_gpio.mdio_num = this->mdio_pin_;

esphome/components/ethernet/ethernet_component.h

@@ -11,10 +11,15 @@
 
 #include "esp_eth.h"
 #include "esp_eth_mac.h"
+#include "esp_eth_mac_esp.h"
 #include "esp_netif.h"
 #include "esp_mac.h"
 #include "esp_idf_version.h"
 
+#if CONFIG_ETH_USE_ESP32_EMAC
+extern "C" eth_esp32_emac_config_t eth_esp32_emac_default_config(void);
+#endif
+
 namespace esphome::ethernet {
 
 #ifdef USE_ETHERNET_IP_STATE_LISTENERS

esphome/components/ethernet/ethernet_helpers.c

@@ -0,0 +1,10 @@
+#include "esp_eth_mac_esp.h"
+
+// ETH_ESP32_EMAC_DEFAULT_CONFIG() uses out-of-order designated initializers
+// which are valid in C but not in C++. This wrapper allows C++ code to get
+// the default config without replicating the macro's contents.
+#if CONFIG_ETH_USE_ESP32_EMAC
+eth_esp32_emac_config_t eth_esp32_emac_default_config(void) {
+  return (eth_esp32_emac_config_t) ETH_ESP32_EMAC_DEFAULT_CONFIG();
+}
+#endif

esphome/components/i2c/__init__.py

@@ -93,11 +93,31 @@ def _bus_declare_type(value):
     raise NotImplementedError
 
 
+def _rp2040_i2c_controller(pin):
+    """Return the I2C controller number (0 or 1) for a given RP2040/RP2350 GPIO pin.
+
+    See RP2040 datasheet Table 2 (section 1.4.3, "GPIO Functions"):
+    https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.pdf
+    See RP2350 datasheet Table 7 (section 9.4, "Function Select"):
+    https://datasheets.raspberrypi.com/rp2350/rp2350-datasheet.pdf
+    """
+    return (pin // 2) % 2
+
+
 def validate_config(config):
     if CORE.is_esp32:
         return cv.require_framework_version(
             esp_idf=cv.Version(5, 4, 2), esp32_arduino=cv.Version(3, 2, 1)
         )(config)
+    if CORE.is_rp2040:
+        sda_controller = _rp2040_i2c_controller(config[CONF_SDA])
+        scl_controller = _rp2040_i2c_controller(config[CONF_SCL])
+        if sda_controller != scl_controller:
+            raise cv.Invalid(
+                f"SDA pin GPIO{config[CONF_SDA]} is on I2C{sda_controller} but "
+                f"SCL pin GPIO{config[CONF_SCL]} is on I2C{scl_controller}. "
+                f"Both pins must be on the same I2C controller."
+            )
     return config
 
 
@@ -146,6 +166,23 @@ def _final_validate(config):
     full_config = fv.full_config.get()[CONF_I2C]
     if CORE.using_zephyr and len(full_config) > 1:
         raise cv.Invalid("Second i2c is not implemented on Zephyr yet")
+    if CORE.is_rp2040:
+        if len(full_config) > 2:
+            raise cv.Invalid(
+                "The maximum number of I2C interfaces for RP2040/RP2350 is 2"
+            )
+        if len(full_config) > 1:
+            controllers = [
+                _rp2040_i2c_controller(conf[CONF_SDA]) for conf in full_config
+            ]
+            if len(set(controllers)) != len(controllers):
+                raise cv.Invalid(
+                    "Multiple I2C buses are configured to use the same I2C controller. "
+                    "Each bus must use pins on a different controller. "
+                    "The I2C controller is determined by (gpio / 2) % 2: "
+                    "even pin pairs (0-1, 4-5, 8-9, ...) use I2C0, "
+                    "odd pin pairs (2-3, 6-7, 10-11, ...) use I2C1."
+                )
     if CORE.is_esp32 and get_esp32_variant() in ESP32_I2C_CAPABILITIES:
         variant = get_esp32_variant()
         max_num = ESP32_I2C_CAPABILITIES[variant]["NUM"]

esphome/components/i2c/i2c_bus_arduino.cpp

@@ -20,12 +20,14 @@ void ArduinoI2CBus::setup() {
 #if defined(USE_ESP8266)
   wire_ = new TwoWire();  // NOLINT(cppcoreguidelines-owning-memory)
 #elif defined(USE_RP2040)
-  static bool first = true;
-  if (first) {
+  // Select Wire instance based on pin assignment, not definition order.
+  // I2C controller = (gpio / 2) % 2: even pairs (0-1,4-5,...) → I2C0, odd pairs (2-3,6-7,...) → I2C1
+  // RP2040 datasheet Table 2 (section 1.4.3): https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.pdf
+  // RP2350 datasheet Table 7 (section 9.4): https://datasheets.raspberrypi.com/rp2350/rp2350-datasheet.pdf
+  if ((this->sda_pin_ / 2) % 2 == 0) {
     wire_ = &Wire;
-    first = false;
   } else {
-    wire_ = &Wire1;  // NOLINT(cppcoreguidelines-owning-memory)
+    wire_ = &Wire1;
   }
 #endif
 

esphome/components/ledc/ledc_output.cpp

@@ -5,6 +5,10 @@
 
 #include <driver/ledc.h>
 #include <cinttypes>
+#include <esp_private/periph_ctrl.h>
+#if !defined(SOC_LEDC_SUPPORT_FADE_STOP)
+#include <hal/ledc_ll.h>
+#endif
 
 #define CLOCK_FREQUENCY 80e6f
 
@@ -16,10 +20,10 @@
 
 static const uint8_t SETUP_ATTEMPT_COUNT_MAX = 5;
 
-namespace esphome {
-namespace ledc {
+namespace esphome::ledc {
 
 static const char *const TAG = "ledc.output";
+static bool ledc_peripheral_reset_done = false;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
 static const int MAX_RES_BITS = LEDC_TIMER_BIT_MAX - 1;
 #if SOC_LEDC_SUPPORT_HS_MODE
@@ -32,6 +36,28 @@ inline ledc_mode_t get_speed_mode(uint8_t channel) { return channel < 8 ? LEDC_H
 inline ledc_mode_t get_speed_mode(uint8_t) { return LEDC_LOW_SPEED_MODE; }
 #endif
 
+#if !defined(SOC_LEDC_SUPPORT_FADE_STOP)
+// Classic ESP32 (currently the only target without SOC_LEDC_SUPPORT_FADE_STOP) can block in
+// ledc_ll_set_duty_start() while duty_start is set. We check the same conf1.duty_start bit here
+// to defer updates and avoid entering IDF's unbounded wait loop.
+//
+// This intentionally depends on the classic ESP32 LEDC register layout used by IDF's own LL HAL.
+// If another target without SOC_LEDC_SUPPORT_FADE_STOP is introduced, revisit this helper.
+static_assert(
+#if defined(CONFIG_IDF_TARGET_ESP32)
+    true,
+#else
+    false,
+#endif
+    "LEDC duty_start pending check assumes classic ESP32 register layout; "
+    "re-evaluate for this target");
+
+static bool ledc_duty_update_pending(ledc_mode_t speed_mode, ledc_channel_t chan_num) {
+  auto *hw = LEDC_LL_GET_HW();
+  return hw->channel_group[speed_mode].channel[chan_num].conf1.duty_start != 0;
+}
+#endif
+
 float ledc_max_frequency_for_bit_depth(uint8_t bit_depth) {
   return static_cast<float>(CLOCK_FREQUENCY) / static_cast<float>(1 << bit_depth);
 }
@@ -105,21 +131,40 @@ void LEDCOutput::write_state(float state) {
   const uint32_t max_duty = (uint32_t(1) << this->bit_depth_) - 1;
   const float duty_rounded = roundf(state * max_duty);
   auto duty = static_cast<uint32_t>(duty_rounded);
+  if (duty == this->last_duty_) {
+    return;
+  }
+
   ESP_LOGV(TAG, "Setting duty: %" PRIu32 " on channel %u", duty, this->channel_);
   auto speed_mode = get_speed_mode(this->channel_);
   auto chan_num = static_cast<ledc_channel_t>(this->channel_ % 8);
   int hpoint = ledc_angle_to_htop(this->phase_angle_, this->bit_depth_);
   if (duty == max_duty) {
     ledc_stop(speed_mode, chan_num, 1);
+    this->last_duty_ = duty;
   } else if (duty == 0) {
     ledc_stop(speed_mode, chan_num, 0);
+    this->last_duty_ = duty;
   } else {
+#if !defined(SOC_LEDC_SUPPORT_FADE_STOP)
+    if (ledc_duty_update_pending(speed_mode, chan_num)) {
+      ESP_LOGV(TAG, "Skipping LEDC duty update on channel %u while previous duty_start is still set", this->channel_);
+      return;
+    }
+#endif
     ledc_set_duty_with_hpoint(speed_mode, chan_num, duty, hpoint);
     ledc_update_duty(speed_mode, chan_num);
+    this->last_duty_ = duty;
   }
 }
 
 void LEDCOutput::setup() {
+  if (!ledc_peripheral_reset_done) {
+    ESP_LOGV(TAG, "Resetting LEDC peripheral to clear stale state after reboot");
+    periph_module_reset(PERIPH_LEDC_MODULE);
+    ledc_peripheral_reset_done = true;
+  }
+
   auto speed_mode = get_speed_mode(this->channel_);
   auto timer_num = static_cast<ledc_timer_t>((this->channel_ % 8) / 2);
   auto chan_num = static_cast<ledc_channel_t>(this->channel_ % 8);
@@ -207,12 +252,12 @@ void LEDCOutput::update_frequency(float frequency) {
   this->status_clear_error();
 
   // re-apply duty
+  this->last_duty_ = UINT32_MAX;
   this->write_state(this->duty_);
 }
 
 uint8_t next_ledc_channel = 0;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
-}  // namespace ledc
-}  // namespace esphome
+}  // namespace esphome::ledc
 
 #endif

esphome/components/ledc/ledc_output.h

@@ -4,11 +4,11 @@
 #include "esphome/core/hal.h"
 #include "esphome/core/automation.h"
 #include "esphome/components/output/float_output.h"
+#include <cstdint>
 
 #ifdef USE_ESP32
 
-namespace esphome {
-namespace ledc {
+namespace esphome::ledc {
 
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
 extern uint8_t next_ledc_channel;
@@ -39,6 +39,7 @@ class LEDCOutput : public output::FloatOutput, public Component {
   float phase_angle_{0.0f};
   float frequency_{};
   float duty_{0.0f};
+  uint32_t last_duty_{UINT32_MAX};
   bool initialized_ = false;
 };
 
@@ -56,7 +57,6 @@ template<typename... Ts> class SetFrequencyAction : public Action<Ts...> {
   LEDCOutput *parent_;
 };
 
-}  // namespace ledc
-}  // namespace esphome
+}  // namespace esphome::ledc
 
 #endif

esphome/components/light/light_call.cpp

@@ -214,7 +214,14 @@ LightColorValues LightCall::validate_() {
   if (this->has_brightness() && this->brightness_ == 0.0f) {
     this->state_ = false;
     this->set_flag_(FLAG_HAS_STATE);
-    this->brightness_ = 1.0f;
+    if (color_mode & ColorCapability::BRIGHTNESS) {
+      // Reset brightness so the light has nonzero brightness when turned back on.
+      this->brightness_ = 1.0f;
+    } else {
+      // Light doesn't support brightness; clear the flag to avoid a spurious
+      // "brightness not supported" warning during capability validation.
+      this->clear_flag_(FLAG_HAS_BRIGHTNESS);
+    }
   }
 
   // Set color brightness to 100% if currently zero and a color is set.
@@ -506,7 +513,7 @@ color_mode_bitmask_t LightCall::get_suitable_color_modes_mask_() {
 
 LightCall &LightCall::set_effect(const char *effect, size_t len) {
   if (len == 4 && strncasecmp(effect, "none", 4) == 0) {
-    this->set_effect(0);
+    this->set_effect(uint32_t{0});
     return *this;
   }
 

esphome/components/light/light_call.h

@@ -130,6 +130,8 @@ class LightCall {
   LightCall &set_effect(optional<std::string> effect);
   /// Set the effect of the light by its name.
   LightCall &set_effect(const std::string &effect) { return this->set_effect(effect.data(), effect.size()); }
+  /// Set the effect of the light by its name (const char * overload to resolve ambiguity).
+  LightCall &set_effect(const char *effect) { return this->set_effect(effect, strlen(effect)); }
   /// Set the effect of the light by its name and length (zero-copy from API).
   LightCall &set_effect(const char *effect, size_t len);
   /// Set the effect of the light by its internal index number (only for internal use).

esphome/components/logger/logger_esp32.cpp

@@ -1,6 +1,7 @@
 #ifdef USE_ESP32
 #include "logger.h"
 
+#include "esphome/components/esp32/crash_handler.h"
 #include <esp_log.h>
 
 #include <driver/uart.h>
@@ -117,6 +118,9 @@ void Logger::pre_setup() {
   esp_log_set_vprintf(esp_idf_log_vprintf_);
 
   ESP_LOGI(TAG, "Log initialized");
+#ifdef USE_ESP32_CRASH_HANDLER
+  esp32::crash_handler_log();
+#endif
 }
 
 void HOT Logger::write_msg_(const char *msg, uint16_t len) {

esphome/components/logger/logger_rp2040.cpp

@@ -1,6 +1,9 @@
 #ifdef USE_RP2040
 #include "logger.h"
+#include "esphome/core/defines.h"
+#ifdef USE_RP2040_CRASH_HANDLER
 #include "esphome/components/rp2040/crash_handler.h"
+#endif
 #include "esphome/core/log.h"
 
 namespace esphome::logger {
@@ -26,7 +29,9 @@ void Logger::pre_setup() {
   }
   global_logger = this;
   ESP_LOGI(TAG, "Log initialized");
+#ifdef USE_RP2040_CRASH_HANDLER
   rp2040::crash_handler_log();
+#endif
 }
 
 void HOT Logger::write_msg_(const char *msg, uint16_t len) {

esphome/components/mdns/mdns_component.h

@@ -129,6 +129,10 @@ class MDNSComponent final : public Component {
 #endif
 #ifdef USE_MDNS_STORE_SERVICES
   StaticVector<MDNSService, MDNS_SERVICE_COUNT> services_{};
+#endif
+#ifdef USE_RP2040
+  bool was_connected_{false};
+  bool initialized_{false};
 #endif
   void compile_records_(StaticVector<MDNSService, MDNS_SERVICE_COUNT> &services, char *mac_address_buf);
 };

esphome/components/mdns/mdns_rp2040.cpp

@@ -7,7 +7,12 @@
 #include "esphome/core/log.h"
 #include "mdns_component.h"
 
+// Arduino-Pico's PolledTimeout.h (pulled in by ESP8266mDNS.h) redefines IRAM_ATTR to empty.
+// Save and restore our definition around the include to avoid a redefinition warning.
+#pragma push_macro("IRAM_ATTR")
+#undef IRAM_ATTR
 #include <ESP8266mDNS.h>
+#pragma pop_macro("IRAM_ATTR")
 
 namespace esphome::mdns {
 
@@ -36,12 +41,32 @@ static void register_rp2040(MDNSComponent *, StaticVector<MDNSService, MDNS_SERV
 }
 
 void MDNSComponent::setup() {
-  this->setup_buffers_and_register_(register_rp2040);
-  // Schedule MDNS.update() via set_interval() instead of overriding loop().
-  // This removes the component from the per-iteration loop list entirely,
-  // eliminating virtual dispatch overhead on every main loop cycle.
-  // See MDNS_UPDATE_INTERVAL_MS comment in mdns_component.h for safety analysis.
-  this->set_interval(MDNS_UPDATE_INTERVAL_MS, []() { MDNS.update(); });
+  // RP2040's LEAmDNS library registers a LwipIntf::stateUpCB() callback to restart
+  // mDNS when the network interface reconnects. However, stateUpCB() is stubbed out
+  // in arduino-pico's LwipIntfCB.cpp because the original ESP8266 implementation used
+  // schedule_function() which doesn't exist in arduino-pico, and the callback can't
+  // safely run directly since netif status callbacks fire from IRQ context
+  // (PICO_CYW43_ARCH_THREADSAFE_BACKGROUND) while _restart() allocates UDP sockets.
+  //
+  // Workaround: defer MDNS.begin() and service registration until the network is
+  // connected (has an IP), then call notifyAPChange() on subsequent reconnects to
+  // restart mDNS probing and announcing — all from main loop context so it's
+  // thread-safe.
+  this->set_interval(MDNS_UPDATE_INTERVAL_MS, [this]() {
+    bool connected = network::is_connected();
+    if (connected && !this->was_connected_) {
+      if (!this->initialized_) {
+        this->setup_buffers_and_register_(register_rp2040);
+        this->initialized_ = true;
+      } else {
+        MDNS.notifyAPChange();
+      }
+    }
+    this->was_connected_ = connected;
+    if (this->initialized_) {
+      MDNS.update();
+    }
+  });
 }
 
 void MDNSComponent::on_shutdown() {

esphome/components/mipi_dsi/mipi_dsi.cpp

@@ -54,6 +54,17 @@ void MIPI_DSI::setup() {
     this->smark_failed(LOG_STR("new_panel_io_dbi failed"), err);
     return;
   }
+  // clang-format off
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(6, 0, 0)
+  auto color_format = LCD_COLOR_FMT_RGB565;
+  if (this->color_depth_ == display::COLOR_BITNESS_888) {
+    color_format = LCD_COLOR_FMT_RGB888;
+  }
+  esp_lcd_dpi_panel_config_t dpi_config = {.virtual_channel = 0,
+                                           .dpi_clk_src = MIPI_DSI_DPI_CLK_SRC_DEFAULT,
+                                           .dpi_clock_freq_mhz = this->pclk_frequency_,
+                                           .in_color_format = color_format,
+#else
   auto pixel_format = LCD_COLOR_PIXEL_FORMAT_RGB565;
   if (this->color_depth_ == display::COLOR_BITNESS_888) {
     pixel_format = LCD_COLOR_PIXEL_FORMAT_RGB888;
@@ -62,6 +73,7 @@ void MIPI_DSI::setup() {
                                            .dpi_clk_src = MIPI_DSI_DPI_CLK_SRC_DEFAULT,
                                            .dpi_clock_freq_mhz = this->pclk_frequency_,
                                            .pixel_format = pixel_format,
+#endif
                                            .num_fbs = 1,  // number of frame buffers to allocate
                                            .video_timing =
                                                {
@@ -77,6 +89,7 @@ void MIPI_DSI::setup() {
                                            .flags = {
                                                .use_dma2d = true,
                                            }};
+  // clang-format on
   err = esp_lcd_new_panel_dpi(this->bus_handle_, &dpi_config, &this->handle_);
   if (err != ESP_OK) {
     this->smark_failed(LOG_STR("esp_lcd_new_panel_dpi failed"), err);

esphome/components/modbus/modbus.cpp

@@ -125,13 +125,17 @@ bool Modbus::parse_modbus_byte_(uint8_t byte) {
   // Byte 0: modbus address (match all)
   if (at == 0)
     return true;
-  uint8_t address = raw[0];
-  uint8_t function_code = raw[1];
+  // Byte 1: function code
+  if (at == 1)
+    return true;
   // Byte 2: Size (with modbus rtu function code 4/3)
   // See also https://en.wikipedia.org/wiki/Modbus
   if (at == 2)
     return true;
 
+  uint8_t address = raw[0];
+  uint8_t function_code = raw[1];
+
   uint8_t data_len = raw[2];
   uint8_t data_offset = 3;
 
@@ -146,10 +150,6 @@ bool Modbus::parse_modbus_byte_(uint8_t byte) {
     // chance that this is a complete message ... admittedly there is a small chance is
     // isn't but that is quite small given the purpose of the CRC in the first place
 
-    // Fewer than 2 bytes can't calc CRC
-    if (at < 2)
-      return true;
-
     data_len = at - 2;
     data_offset = 1;
 

esphome/components/one_wire/one_wire.cpp

@@ -13,6 +13,11 @@ const std::string &OneWireDevice::get_address_name() {
   return this->address_name_;
 }
 
+void OneWireDevice::set_address(uint64_t address) {
+  this->address_ = address;
+  this->address_name_.clear();
+}
+
 bool OneWireDevice::send_command_(uint8_t cmd) {
   if (!this->bus_->select(this->address_))
     return false;

esphome/components/one_wire/one_wire.h

@@ -15,7 +15,7 @@ class OneWireDevice {
  public:
   /// @brief store the address of the device
   /// @param address of the device
-  void set_address(uint64_t address) { this->address_ = address; }
+  void set_address(uint64_t address);
 
   void set_index(uint8_t index) { this->index_ = index; }
 

esphome/components/ota/ota_backend_esp8266.cpp

@@ -105,6 +105,7 @@ OTAResponseTypes ESP8266OTABackend::begin(size_t image_size) {
 
   this->current_address_ = this->start_address_;
   this->image_size_ = image_size;
+  this->bytes_received_ = 0;
   this->buffer_len_ = 0;
   this->md5_set_ = false;
 
@@ -140,6 +141,7 @@ OTAResponseTypes ESP8266OTABackend::write(uint8_t *data, size_t len) {
     size_t to_buffer = std::min(len - written, this->buffer_size_ - this->buffer_len_);
     memcpy(this->buffer_.get() + this->buffer_len_, data + written, to_buffer);
     this->buffer_len_ += to_buffer;
+    this->bytes_received_ += to_buffer;
     written += to_buffer;
 
     // If buffer is full, write to flash
@@ -252,8 +254,8 @@ OTAResponseTypes ESP8266OTABackend::end() {
     }
   }
 
-  // Calculate actual bytes written
-  size_t actual_size = this->current_address_ - this->start_address_;
+  // Calculate actual bytes written (exact uploaded size, excluding flash write padding)
+  size_t actual_size = this->bytes_received_;
 
   // Check if any data was written
   if (actual_size == 0) {
@@ -304,6 +306,7 @@ void ESP8266OTABackend::abort() {
   this->buffer_.reset();
   this->buffer_len_ = 0;
   this->image_size_ = 0;
+  this->bytes_received_ = 0;
   esp8266::preferences_prevent_write(false);
 }
 

esphome/components/ota/ota_backend_esp8266.h

@@ -48,6 +48,7 @@ class ESP8266OTABackend final {
   uint32_t start_address_{0};
   uint32_t current_address_{0};
   size_t image_size_{0};
+  size_t bytes_received_{0};
 
   md5::MD5Digest md5_{};
   uint8_t expected_md5_[16];  // Fixed-size buffer for 128-bit (16-byte) MD5 digest

esphome/components/pid/climate.py

@@ -57,7 +57,7 @@ CONFIG_SCHEMA = cv.All(
                     cv.Optional(CONF_KD_MULTIPLIER, default=0.0): cv.float_,
                     cv.Optional(
                         CONF_DEADBAND_OUTPUT_AVERAGING_SAMPLES, default=1
-                    ): cv.int_,
+                    ): cv.positive_not_null_int,
                 }
             ),
             cv.Required(CONF_CONTROL_PARAMETERS): cv.Schema(
@@ -68,8 +68,12 @@ CONFIG_SCHEMA = cv.All(
                     cv.Optional(CONF_STARTING_INTEGRAL_TERM, default=0.0): cv.float_,
                     cv.Optional(CONF_MIN_INTEGRAL, default=-1): cv.float_,
                     cv.Optional(CONF_MAX_INTEGRAL, default=1): cv.float_,
-                    cv.Optional(CONF_DERIVATIVE_AVERAGING_SAMPLES, default=1): cv.int_,
-                    cv.Optional(CONF_OUTPUT_AVERAGING_SAMPLES, default=1): cv.int_,
+                    cv.Optional(
+                        CONF_DERIVATIVE_AVERAGING_SAMPLES, default=1
+                    ): cv.positive_not_null_int,
+                    cv.Optional(
+                        CONF_OUTPUT_AVERAGING_SAMPLES, default=1
+                    ): cv.positive_not_null_int,
                 }
             ),
         }
@@ -102,13 +106,15 @@ async def to_code(config):
     cg.add(var.set_starting_integral_term(params[CONF_STARTING_INTEGRAL_TERM]))
     cg.add(var.set_derivative_samples(params[CONF_DERIVATIVE_AVERAGING_SAMPLES]))
 
-    cg.add(var.set_output_samples(params[CONF_OUTPUT_AVERAGING_SAMPLES]))
+    output_samples = params[CONF_OUTPUT_AVERAGING_SAMPLES]
+    cg.add(var.set_output_samples(output_samples))
 
     if CONF_MIN_INTEGRAL in params:
         cg.add(var.set_min_integral(params[CONF_MIN_INTEGRAL]))
     if CONF_MAX_INTEGRAL in params:
         cg.add(var.set_max_integral(params[CONF_MAX_INTEGRAL]))
 
+    deadband_output_samples = 1
     if CONF_DEADBAND_PARAMETERS in config:
         params = config[CONF_DEADBAND_PARAMETERS]
         cg.add(var.set_threshold_low(params[CONF_THRESHOLD_LOW]))
@@ -116,11 +122,11 @@ async def to_code(config):
         cg.add(var.set_kp_multiplier(params[CONF_KP_MULTIPLIER]))
         cg.add(var.set_ki_multiplier(params[CONF_KI_MULTIPLIER]))
         cg.add(var.set_kd_multiplier(params[CONF_KD_MULTIPLIER]))
-        cg.add(
-            var.set_deadband_output_samples(
-                params[CONF_DEADBAND_OUTPUT_AVERAGING_SAMPLES]
-            )
-        )
+        deadband_output_samples = params[CONF_DEADBAND_OUTPUT_AVERAGING_SAMPLES]
+        cg.add(var.set_deadband_output_samples(deadband_output_samples))
+
+    # Single shared output buffer sized to max of both modes
+    cg.add(var.init_output_buffer(max(output_samples, deadband_output_samples)))
 
     cg.add(var.set_default_target_temperature(config[CONF_DEFAULT_TARGET_TEMPERATURE]))
 

esphome/components/pid/pid_climate.h

@@ -28,7 +28,11 @@ class PIDClimate : public climate::Climate, public Component {
   void set_min_integral(float min_integral) { controller_.min_integral_ = min_integral; }
   void set_max_integral(float max_integral) { controller_.max_integral_ = max_integral; }
   void set_output_samples(int in) { controller_.output_samples_ = in; }
-  void set_derivative_samples(int in) { controller_.derivative_samples_ = in; }
+  void set_derivative_samples(int in) {
+    controller_.derivative_samples_ = in;
+    if (in > 1)  // No allocation needed when samples=1 (ring_buffer_average_ short-circuits)
+      controller_.derivative_window_.init(in);
+  }
 
   void set_threshold_low(float in) { controller_.threshold_low_ = in; }
   void set_threshold_high(float in) { controller_.threshold_high_ = in; }
@@ -38,6 +42,10 @@ class PIDClimate : public climate::Climate, public Component {
   void set_starting_integral_term(float in) { controller_.set_starting_integral_term(in); }
 
   void set_deadband_output_samples(int in) { controller_.deadband_output_samples_ = in; }
+  void init_output_buffer(int size) {
+    if (size > 1)  // No allocation needed when samples=1 (ring_buffer_average_ short-circuits)
+      controller_.output_window_.init(size);
+  }
 
   float get_output_value() const { return output_value_; }
   float get_error_value() const { return controller_.error_; }

esphome/components/pid/pid_controller.cpp

@@ -21,9 +21,9 @@ float PIDController::update(float setpoint, float process_value) {
   // u(t) := p(t) + i(t) + d(t)
   float output = proportional_term_ + integral_term_ + derivative_term_;
 
-  // smooth/sample the output
+  // smooth/sample the output using shared buffer with mode-appropriate sample count
   int samples = in_deadband() ? deadband_output_samples_ : output_samples_;
-  return weighted_average_(output_list_, output, samples);
+  return ring_buffer_average_(output_window_, output, samples);
 }
 
 bool PIDController::in_deadband() {
@@ -83,7 +83,7 @@ void PIDController::calculate_derivative_term_(float setpoint) {
   previous_setpoint_ = setpoint;
 
   // smooth the derivative samples
-  derivative = weighted_average_(derivative_list_, derivative, derivative_samples_);
+  derivative = ring_buffer_average_(derivative_window_, derivative, derivative_samples_);
 
   derivative_term_ = kd_ * derivative;
 
@@ -93,25 +93,23 @@ void PIDController::calculate_derivative_term_(float setpoint) {
   }
 }
 
-float PIDController::weighted_average_(std::deque<float> &list, float new_value, int samples) {
-  // if only 1 sample needed, clear the list and return
-  if (samples == 1) {
-    list.clear();
+float PIDController::ring_buffer_average_(FixedRingBuffer<float> &buf, float new_value, int max_samples) {
+  // if only 1 sample needed (or invalid), clear the buffer and return
+  if (max_samples <= 1) {
+    buf.clear();
     return new_value;
   }
 
-  // add the new item to the list
-  list.push_front(new_value);
+  // Trim oldest entries to make room (handles mode-switching where buffer
+  // may have more entries than the current mode needs)
+  while (buf.size() >= static_cast<size_t>(max_samples))
+    buf.pop();
+  buf.push(new_value);
 
-  // keep only 'samples' readings, by popping off the back of the list
-  while (samples > 0 && list.size() > static_cast<size_t>(samples))
-    list.pop_back();
-
-  // calculate and return the average of all values in the list
   float sum = 0;
-  for (auto &elem : list)
-    sum += elem;
-  return sum / list.size();
+  for (auto val : buf)
+    sum += val;
+  return sum / buf.size();
 }
 
 float PIDController::calculate_relative_time_() {

esphome/components/pid/pid_controller.h

@@ -1,6 +1,7 @@
 #pragma once
+
 #include "esphome/core/hal.h"
-#include <deque>
+#include "esphome/core/helpers.h"
 #include <cmath>
 
 namespace esphome {
@@ -24,10 +25,10 @@ struct PIDController {
   /// Differential gain K_d.
   float kd_ = 0;
 
-  // smooth the derivative value using a weighted average over X samples
-  int derivative_samples_ = 8;
+  // smooth the derivative value using an average over X samples
+  int derivative_samples_ = 1;
 
-  /// smooth the output value using a weighted average over X values
+  /// smooth the output value using an average over X values
   int output_samples_ = 1;
 
   float threshold_low_ = 0.0f;
@@ -50,7 +51,10 @@ struct PIDController {
   void calculate_proportional_term_();
   void calculate_integral_term_();
   void calculate_derivative_term_(float setpoint);
-  float weighted_average_(std::deque<float> &list, float new_value, int samples);
+
+  /// Ring buffer smoothing using FixedRingBuffer (single allocation at setup)
+  float ring_buffer_average_(FixedRingBuffer<float> &buf, float new_value, int max_samples);
+
   float calculate_relative_time_();
 
   /// Error from previous update used for derivative term
@@ -60,12 +64,12 @@ struct PIDController {
   float accumulated_integral_ = 0;
   uint32_t last_time_ = 0;
 
-  // this is a list of derivative values for smoothing.
-  std::deque<float> derivative_list_;
+  // Ring buffer for derivative smoothing
+  FixedRingBuffer<float> derivative_window_;
 
-  // this is a list of output values for smoothing.
-  std::deque<float> output_list_;
+  // Ring buffer for output smoothing (shared between normal and deadband modes)
+  FixedRingBuffer<float> output_window_;
 
-};  // Struct PID Controller
+};  // Struct PIDController
 }  // namespace pid
 }  // namespace esphome

esphome/components/pid/sensor/__init__.py

@@ -1,5 +1,6 @@
 import esphome.codegen as cg
 from esphome.components import sensor
+from esphome.components.const import CONF_CLIMATE_ID
 import esphome.config_validation as cv
 from esphome.const import CONF_TYPE, ICON_GAUGE, STATE_CLASS_MEASUREMENT, UNIT_PERCENT
 
@@ -21,7 +22,6 @@ PID_CLIMATE_SENSOR_TYPES = {
     "KD": PIDClimateSensorType.PID_SENSOR_TYPE_KD,
 }
 
-CONF_CLIMATE_ID = "climate_id"
 CONFIG_SCHEMA = (
     sensor.sensor_schema(
         PIDClimateSensor,

esphome/components/remote_receiver/remote_receiver_rmt.cpp

@@ -44,7 +44,6 @@ void RemoteReceiverComponent::setup() {
   channel.intr_priority = 0;
   channel.flags.invert_in = 0;
   channel.flags.with_dma = this->with_dma_;
-  channel.flags.io_loop_back = 0;
   esp_err_t error = rmt_new_rx_channel(&channel, &this->channel_);
   if (error != ESP_OK) {
     this->error_code_ = error;

esphome/components/remote_transmitter/remote_transmitter_rmt.cpp

@@ -120,11 +120,13 @@ void RemoteTransmitterComponent::configure_rmt_() {
     channel.gpio_num = gpio_num_t(this->pin_->get_pin());
     channel.mem_block_symbols = this->rmt_symbols_;
     channel.trans_queue_depth = 1;
-    channel.flags.io_loop_back = open_drain;
-    channel.flags.io_od_mode = open_drain;
     channel.flags.invert_out = 0;
     channel.flags.with_dma = this->with_dma_;
     channel.intr_priority = 0;
+#if ESP_IDF_VERSION < ESP_IDF_VERSION_VAL(6, 0, 0)
+    channel.flags.io_loop_back = open_drain;
+    channel.flags.io_od_mode = open_drain;
+#endif
     error = rmt_new_tx_channel(&channel, &this->channel_);
     if (error != ESP_OK) {
       this->error_code_ = error;
@@ -136,6 +138,13 @@ void RemoteTransmitterComponent::configure_rmt_() {
       this->mark_failed();
       return;
     }
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(6, 0, 0)
+    if (open_drain) {
+      gpio_num_t gpio = gpio_num_t(this->pin_->get_pin());
+      gpio_od_enable(gpio);
+      gpio_input_enable(gpio);
+    }
+#endif
     if (this->pin_->get_flags() & gpio::FLAG_PULLUP) {
       gpio_pullup_en(gpio_num_t(this->pin_->get_pin()));
     } else {

esphome/components/rp2040/__init__.py

@@ -203,7 +203,12 @@ async def to_code(config):
             cg.add_build_flag(f"-Wl,--wrap={symbol}")
 
     cg.add_platformio_option("board_build.core", "earlephilhower")
-    cg.add_platformio_option("board_build.filesystem_size", "1m")
+    # In testing mode, use all flash for sketch to allow linking grouped component tests.
+    # Real RP2040 hardware uses 1MB filesystem + 1MB sketch, but CI tests may combine
+    # many components that exceed the 1MB sketch partition.
+    cg.add_platformio_option(
+        "board_build.filesystem_size", "0m" if CORE.testing_mode else "1m"
+    )
 
     ver: cv.Version = CORE.data[KEY_CORE][KEY_FRAMEWORK_VERSION]
     cg.add_define(
@@ -212,6 +217,7 @@ async def to_code(config):
     )
 
     cg.add_define("USE_RP2040_WATCHDOG_TIMEOUT", config[CONF_WATCHDOG_TIMEOUT])
+    cg.add_define("USE_RP2040_CRASH_HANDLER")
 
 
 def add_pio_file(component: str, key: str, data: str):

esphome/components/rp2040/core.cpp

@@ -1,8 +1,10 @@
 #ifdef USE_RP2040
 
 #include "core.h"
-#include "crash_handler.h"
 #include "esphome/core/defines.h"
+#ifdef USE_RP2040_CRASH_HANDLER
+#include "crash_handler.h"
+#endif
 #include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
 
@@ -25,7 +27,9 @@ void arch_restart() {
 }
 
 void arch_init() {
+#ifdef USE_RP2040_CRASH_HANDLER
   rp2040::crash_handler_read_and_clear();
+#endif
 #if USE_RP2040_WATCHDOG_TIMEOUT > 0
   watchdog_enable(USE_RP2040_WATCHDOG_TIMEOUT, false);
 #endif

esphome/components/rp2040/crash_handler.cpp

@@ -1,5 +1,8 @@
 #ifdef USE_RP2040
 
+#include "esphome/core/defines.h"
+#ifdef USE_RP2040_CRASH_HANDLER
+
 #include "crash_handler.h"
 #include "esphome/core/log.h"
 
@@ -13,13 +16,19 @@
 static constexpr uint32_t EF_LR = 5;
 static constexpr uint32_t EF_PC = 6;
 
-static constexpr uint32_t CRASH_MAGIC = 0xDEADBEEF;
+// Version encoded in the magic value: upper 16 bits are sentinel (0xDEAD),
+// lower 16 bits are the version number. This avoids using a separate scratch
+// register for versioning (we only have 8 total). Future firmware reads the
+// sentinel to confirm it's crash data, then the version to know the layout.
+static constexpr uint32_t CRASH_MAGIC_SENTINEL = 0xDEAD0000;
+static constexpr uint32_t CRASH_DATA_VERSION = 1;
+static constexpr uint32_t CRASH_MAGIC_V1 = CRASH_MAGIC_SENTINEL | CRASH_DATA_VERSION;
 
 // We only have 8 scratch registers (32 bytes) that survive watchdog reboot.
 // Use them for the most important data, then scan the stack for code addresses.
 //
 // Scratch register layout:
-// [0] = magic (CRASH_MAGIC)
+// [0] = versioned magic (upper 16 bits = 0xDEAD sentinel, lower 16 bits = version)
 // [1] = PC (program counter at fault)
 // [2] = LR (link register from exception frame)
 // [3] = SP (stack pointer at fault)
@@ -48,18 +57,21 @@ static const char *const TAG = "rp2040.crash";
 
 // Placed in .noinit so BSS zero-init cannot race with crash_handler_read_and_clear().
 // The valid field is explicitly cleared in crash_handler_read_and_clear() instead.
-static struct {
+static struct CrashData {
   bool valid;
   uint32_t pc;
   uint32_t lr;
   uint32_t sp;
   uint32_t backtrace[MAX_BACKTRACE];
   uint8_t backtrace_count;
-} __attribute__((section(".noinit"))) s_crash_data;
+} s_crash_data __attribute__((section(".noinit")));
+
+bool crash_handler_has_data() { return s_crash_data.valid; }
 
 void crash_handler_read_and_clear() {
   s_crash_data.valid = false;
-  if (watchdog_hw->scratch[0] == CRASH_MAGIC) {
+  uint32_t magic = watchdog_hw->scratch[0];
+  if ((magic & 0xFFFF0000) == CRASH_MAGIC_SENTINEL && (magic & 0xFFFF) == CRASH_DATA_VERSION) {
     s_crash_data.valid = true;
     s_crash_data.pc = watchdog_hw->scratch[1];
     s_crash_data.lr = watchdog_hw->scratch[2];
@@ -135,7 +147,7 @@ static void __attribute__((used, noreturn)) hard_fault_handler_c(uint32_t *frame
   // by a stacking error or corrupted SP, frame may be invalid. Write a minimal
   // crash marker so we at least know a crash occurred.
   if (!is_valid_sram_ptr(frame)) {
-    watchdog_hw->scratch[0] = CRASH_MAGIC;
+    watchdog_hw->scratch[0] = CRASH_MAGIC_V1;
     watchdog_hw->scratch[1] = 0;                                   // PC unknown
     watchdog_hw->scratch[2] = 0;                                   // LR unknown
     watchdog_hw->scratch[3] = reinterpret_cast<uintptr_t>(frame);  // Record the bad SP for diagnosis
@@ -157,7 +169,7 @@ static void __attribute__((used, noreturn)) hard_fault_handler_c(uint32_t *frame
   uint32_t pre_fault_sp = reinterpret_cast<uintptr_t>(post_frame);
 
   // Write key registers
-  watchdog_hw->scratch[0] = CRASH_MAGIC;
+  watchdog_hw->scratch[0] = CRASH_MAGIC_V1;
   watchdog_hw->scratch[1] = frame[EF_PC];
   watchdog_hw->scratch[2] = frame[EF_LR];
   watchdog_hw->scratch[3] = pre_fault_sp;
@@ -224,4 +236,5 @@ extern "C" void __attribute__((naked, used)) isr_hardfault() {
                  : "i"(hard_fault_handler_c));
 }
 
+#endif  // USE_RP2040_CRASH_HANDLER
 #endif  // USE_RP2040

esphome/components/rp2040/crash_handler.h

@@ -2,7 +2,9 @@
 
 #ifdef USE_RP2040
 
-#include <cstdint>
+#include "esphome/core/defines.h"
+
+#ifdef USE_RP2040_CRASH_HANDLER
 
 namespace esphome::rp2040 {
 
@@ -12,6 +14,10 @@ void crash_handler_read_and_clear();
 /// Log crash data if a crash was detected on previous boot.
 void crash_handler_log();
 
+/// Returns true if crash data was found this boot.
+bool crash_handler_has_data();
+
 }  // namespace esphome::rp2040
 
+#endif  // USE_RP2040_CRASH_HANDLER
 #endif  // USE_RP2040

esphome/components/rp2040/generate_boards.py

@@ -6,6 +6,7 @@ Usage: python esphome/components/rp2040/generate_boards.py <arduino-pico-path>
 import json
 from pathlib import Path
 import re
+import subprocess
 import sys
 
 from jinja2 import Environment, FileSystemLoader
@@ -157,7 +158,7 @@ def generate(arduino_pico_path: Path) -> str:
     board_pins, boards = load_boards(arduino_pico_path)
 
     template = _jinja_env.get_template("boards.jinja2")
-    return template.render(
+    content = template.render(
         cyw43_gpio_offset=CYW43_GPIO_OFFSET,
         cyw43_max_gpio=CYW43_GPIO_OFFSET + CYW43_GPIO_COUNT - 1,
         default_max_pin=DEFAULT_MAX_PIN,
@@ -165,6 +166,15 @@ def generate(arduino_pico_path: Path) -> str:
         boards=sorted(boards.items()),
     )
 
+    # Format output to match pre-commit ruff formatting
+    result = subprocess.run(
+        [sys.executable, "-m", "ruff", "format", "--stdin-filename", "boards.py"],
+        input=content.encode(),
+        capture_output=True,
+        check=True,
+    )
+    return result.stdout.decode()
+
 
 def main():
     if len(sys.argv) < 2:

esphome/components/runtime_image/__init__.py

@@ -74,7 +74,7 @@ class JPEGFormat(Format):
 
     def actions(self) -> None:
         cg.add_define("USE_RUNTIME_IMAGE_JPEG")
-        cg.add_library("JPEGDEC", None, "https://github.com/bitbank2/JPEGDEC#ca1e0f2")
+        cg.add_library("JPEGDEC", "1.8.4", "https://github.com/bitbank2/JPEGDEC#1.8.4")
 
 
 class PNGFormat(Format):

esphome/components/runtime_image/bmp_decoder.h

@@ -26,6 +26,10 @@ class BmpDecoder : public ImageDecoder {
   int HOT decode(uint8_t *buffer, size_t size) override;
 
   bool is_finished() const override {
+    if (this->bits_per_pixel_ == 0) {
+      // header not yet received, so dimensions not yet determined
+      return false;
+    }
     // BMP is finished when we've decoded all pixel data
     return this->paint_index_ >= static_cast<size_t>(this->width_ * this->height_);
   }

esphome/components/select/select_call.cpp

@@ -41,7 +41,7 @@ SelectCall &SelectCall::with_index(size_t index) {
   this->operation_ = SELECT_OP_SET;
   if (index >= this->parent_->size()) {
     ESP_LOGW(TAG, "'%s' - Index value %zu out of bounds", this->parent_->get_name().c_str(), index);
-    this->index_ = {};  // Store nullopt for invalid index
+    this->index_ = nullopt;  // Store nullopt for invalid index
   } else {
     this->index_ = index;
   }
@@ -52,7 +52,7 @@ optional<size_t> SelectCall::calculate_target_index_(const char *name) {
   const auto &options = this->parent_->traits.get_options();
   if (options.empty()) {
     ESP_LOGW(TAG, "'%s' - Select has no options", name);
-    return {};
+    return nullopt;
   }
 
   if (this->operation_ == SELECT_OP_FIRST) {
@@ -67,7 +67,7 @@ optional<size_t> SelectCall::calculate_target_index_(const char *name) {
     ESP_LOGD(TAG, "'%s' - Setting", name);
     if (!this->index_.has_value()) {
       ESP_LOGW(TAG, "'%s' - No option set", name);
-      return {};
+      return nullopt;
     }
     return this->index_;
   }
@@ -96,7 +96,7 @@ optional<size_t> SelectCall::calculate_target_index_(const char *name) {
     return active_index + 1;
   }
 
-  return {};  // Can't navigate further without cycling
+  return nullopt;  // Can't navigate further without cycling
 }
 
 void SelectCall::perform() {

esphome/components/sensor/__init__.py

@@ -403,9 +403,9 @@ async def filter_out_filter_to_code(config, filter_id):
 QUANTILE_SCHEMA = cv.All(
     cv.Schema(
         {
-            cv.Optional(CONF_WINDOW_SIZE, default=5): cv.positive_not_null_int,
-            cv.Optional(CONF_SEND_EVERY, default=5): cv.positive_not_null_int,
-            cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.positive_not_null_int,
+            cv.Optional(CONF_WINDOW_SIZE, default=5): cv.int_range(min=1, max=65535),
+            cv.Optional(CONF_SEND_EVERY, default=5): cv.int_range(min=1, max=65535),
+            cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.int_range(min=1, max=65535),
             cv.Optional(CONF_QUANTILE, default=0.9): cv.zero_to_one_float,
         }
     ),
@@ -427,9 +427,9 @@ async def quantile_filter_to_code(config, filter_id):
 MEDIAN_SCHEMA = cv.All(
     cv.Schema(
         {
-            cv.Optional(CONF_WINDOW_SIZE, default=5): cv.positive_not_null_int,
-            cv.Optional(CONF_SEND_EVERY, default=5): cv.positive_not_null_int,
-            cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.positive_not_null_int,
+            cv.Optional(CONF_WINDOW_SIZE, default=5): cv.int_range(min=1, max=65535),
+            cv.Optional(CONF_SEND_EVERY, default=5): cv.int_range(min=1, max=65535),
+            cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.int_range(min=1, max=65535),
         }
     ),
     validate_send_first_at,
@@ -449,9 +449,9 @@ async def median_filter_to_code(config, filter_id):
 MIN_SCHEMA = cv.All(
     cv.Schema(
         {
-            cv.Optional(CONF_WINDOW_SIZE, default=5): cv.positive_not_null_int,
-            cv.Optional(CONF_SEND_EVERY, default=5): cv.positive_not_null_int,
-            cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.positive_not_null_int,
+            cv.Optional(CONF_WINDOW_SIZE, default=5): cv.int_range(min=1, max=65535),
+            cv.Optional(CONF_SEND_EVERY, default=5): cv.int_range(min=1, max=65535),
+            cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.int_range(min=1, max=65535),
         }
     ),
     validate_send_first_at,
@@ -483,9 +483,9 @@ async def min_filter_to_code(config, filter_id):
 MAX_SCHEMA = cv.All(
     cv.Schema(
         {
-            cv.Optional(CONF_WINDOW_SIZE, default=5): cv.positive_not_null_int,
-            cv.Optional(CONF_SEND_EVERY, default=5): cv.positive_not_null_int,
-            cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.positive_not_null_int,
+            cv.Optional(CONF_WINDOW_SIZE, default=5): cv.int_range(min=1, max=65535),
+            cv.Optional(CONF_SEND_EVERY, default=5): cv.int_range(min=1, max=65535),
+            cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.int_range(min=1, max=65535),
         }
     ),
     validate_send_first_at,
@@ -509,9 +509,9 @@ async def max_filter_to_code(config, filter_id):
 SLIDING_AVERAGE_SCHEMA = cv.All(
     cv.Schema(
         {
-            cv.Optional(CONF_WINDOW_SIZE, default=15): cv.positive_not_null_int,
-            cv.Optional(CONF_SEND_EVERY, default=15): cv.positive_not_null_int,
-            cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.positive_not_null_int,
+            cv.Optional(CONF_WINDOW_SIZE, default=15): cv.int_range(min=1, max=65535),
+            cv.Optional(CONF_SEND_EVERY, default=15): cv.int_range(min=1, max=65535),
+            cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.int_range(min=1, max=65535),
         }
     ),
     validate_send_first_at,
@@ -540,8 +540,8 @@ EXPONENTIAL_AVERAGE_SCHEMA = cv.All(
     cv.Schema(
         {
             cv.Optional(CONF_ALPHA, default=0.1): cv.positive_float,
-            cv.Optional(CONF_SEND_EVERY, default=15): cv.positive_not_null_int,
-            cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.positive_not_null_int,
+            cv.Optional(CONF_SEND_EVERY, default=15): cv.int_range(min=1, max=65535),
+            cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.int_range(min=1, max=65535),
         }
     ),
     validate_send_first_at,

esphome/components/sensor/filter.cpp

@@ -41,26 +41,14 @@ void Filter::initialize(Sensor *parent, Filter *next) {
 }
 
 // SlidingWindowFilter
-SlidingWindowFilter::SlidingWindowFilter(size_t window_size, size_t send_every, size_t send_first_at)
-    : window_size_(window_size), send_every_(send_every), send_at_(send_every - send_first_at) {
-  // Allocate ring buffer once at initialization
+SlidingWindowFilter::SlidingWindowFilter(uint16_t window_size, uint16_t send_every, uint16_t send_first_at)
+    : send_every_(send_every), send_at_(send_every - send_first_at) {
   this->window_.init(window_size);
 }
 
 optional<float> SlidingWindowFilter::new_value(float value) {
-  // Add value to ring buffer
-  if (this->window_count_ < this->window_size_) {
-    // Buffer not yet full - just append
-    this->window_.push_back(value);
-    this->window_count_++;
-  } else {
-    // Buffer full - overwrite oldest value (ring buffer)
-    this->window_[this->window_head_] = value;
-    this->window_head_++;
-    if (this->window_head_ >= this->window_size_) {
-      this->window_head_ = 0;
-    }
-  }
+  // Add value to ring buffer (overwrites oldest when full)
+  this->window_.push_overwrite(value);
 
   // Check if we should send a result
   if (++this->send_at_ >= this->send_every_) {
@@ -77,9 +65,8 @@ FixedVector<float> SortedWindowFilter::get_window_values_() {
   // Copy window without NaN values using FixedVector (no heap allocation)
   // Returns unsorted values - caller will use std::nth_element for partial sorting as needed
   FixedVector<float> values;
-  values.init(this->window_count_);
-  for (size_t i = 0; i < this->window_count_; i++) {
-    float v = this->window_[i];
+  values.init(this->window_.size());
+  for (float v : this->window_) {
     if (!std::isnan(v)) {
       values.push_back(v);
     }
@@ -150,8 +137,7 @@ float MaxFilter::compute_result() { return this->find_extremum_<std::greater<flo
 float SlidingWindowMovingAverageFilter::compute_result() {
   float sum = 0;
   size_t valid_count = 0;
-  for (size_t i = 0; i < this->window_count_; i++) {
-    float v = this->window_[i];
+  for (float v : this->window_) {
     if (!std::isnan(v)) {
       sum += v;
       valid_count++;
@@ -161,7 +147,7 @@ float SlidingWindowMovingAverageFilter::compute_result() {
 }
 
 // ExponentialMovingAverageFilter
-ExponentialMovingAverageFilter::ExponentialMovingAverageFilter(float alpha, size_t send_every, size_t send_first_at)
+ExponentialMovingAverageFilter::ExponentialMovingAverageFilter(float alpha, uint16_t send_every, uint16_t send_first_at)
     : alpha_(alpha), send_every_(send_every), send_at_(send_every - send_first_at) {}
 optional<float> ExponentialMovingAverageFilter::new_value(float value) {
   if (!std::isnan(value)) {
@@ -183,7 +169,7 @@ optional<float> ExponentialMovingAverageFilter::new_value(float value) {
   }
   return {};
 }
-void ExponentialMovingAverageFilter::set_send_every(size_t send_every) { this->send_every_ = send_every; }
+void ExponentialMovingAverageFilter::set_send_every(uint16_t send_every) { this->send_every_ = send_every; }
 void ExponentialMovingAverageFilter::set_alpha(float alpha) { this->alpha_ = alpha; }
 
 // ThrottleAverageFilter
@@ -511,7 +497,7 @@ optional<float> ToNTCTemperatureFilter::new_value(float value) {
 }
 
 // StreamingFilter (base class)
-StreamingFilter::StreamingFilter(size_t window_size, size_t send_first_at)
+StreamingFilter::StreamingFilter(uint16_t window_size, uint16_t send_first_at)
     : window_size_(window_size), send_first_at_(send_first_at) {}
 
 optional<float> StreamingFilter::new_value(float value) {

esphome/components/sensor/filter.h

@@ -52,7 +52,7 @@ class Filter {
  */
 class SlidingWindowFilter : public Filter {
  public:
-  SlidingWindowFilter(size_t window_size, size_t send_every, size_t send_first_at);
+  SlidingWindowFilter(uint16_t window_size, uint16_t send_every, uint16_t send_first_at);
 
   optional<float> new_value(float value) final;
 
@@ -60,14 +60,10 @@ class SlidingWindowFilter : public Filter {
   /// Called by new_value() to compute the filtered result from the current window
   virtual float compute_result() = 0;
 
-  /// Access the sliding window values (ring buffer implementation)
-  /// Use: for (size_t i = 0; i < window_count_; i++) { float val = window_[i]; }
-  FixedVector<float> window_;
-  size_t window_head_{0};   ///< Index where next value will be written
-  size_t window_count_{0};  ///< Number of valid values in window (0 to window_size_)
-  size_t window_size_;      ///< Maximum window size
-  size_t send_every_;       ///< Send result every N values
-  size_t send_at_;          ///< Counter for send_every
+  /// Sliding window ring buffer - automatically overwrites oldest values when full
+  FixedRingBuffer<float> window_;
+  uint16_t send_every_;  ///< Send result every N values
+  uint16_t send_at_;     ///< Counter for send_every
 };
 
 /** Base class for Min/Max filters.
@@ -84,8 +80,7 @@ class MinMaxFilter : public SlidingWindowFilter {
   template<typename Compare> float find_extremum_() {
     float result = NAN;
     Compare comp;
-    for (size_t i = 0; i < this->window_count_; i++) {
-      float v = this->window_[i];
+    for (float v : this->window_) {
       if (!std::isnan(v)) {
         result = std::isnan(result) ? v : (comp(v, result) ? v : result);
       }
@@ -239,18 +234,18 @@ class SlidingWindowMovingAverageFilter : public SlidingWindowFilter {
  */
 class ExponentialMovingAverageFilter : public Filter {
  public:
-  ExponentialMovingAverageFilter(float alpha, size_t send_every, size_t send_first_at);
+  ExponentialMovingAverageFilter(float alpha, uint16_t send_every, uint16_t send_first_at);
 
   optional<float> new_value(float value) override;
 
-  void set_send_every(size_t send_every);
+  void set_send_every(uint16_t send_every);
   void set_alpha(float alpha);
 
  protected:
   float accumulator_{NAN};
   float alpha_;
-  size_t send_every_;
-  size_t send_at_;
+  uint16_t send_every_;
+  uint16_t send_at_;
   bool first_value_{true};
 };
 
@@ -570,7 +565,7 @@ class ToNTCTemperatureFilter : public Filter {
  */
 class StreamingFilter : public Filter {
  public:
-  StreamingFilter(size_t window_size, size_t send_first_at);
+  StreamingFilter(uint16_t window_size, uint16_t send_first_at);
 
   optional<float> new_value(float value) final;
 
@@ -584,9 +579,9 @@ class StreamingFilter : public Filter {
   /// Called by new_value() to reset internal state after sending a result
   virtual void reset_batch() = 0;
 
-  size_t window_size_;
-  size_t count_{0};
-  size_t send_first_at_;
+  uint16_t window_size_;
+  uint16_t count_{0};
+  uint16_t send_first_at_;
   bool first_send_{true};
 };
 

esphome/components/socket/bsd_sockets_impl.h

@@ -14,7 +14,7 @@
 #endif
 
 #ifdef USE_LWIP_FAST_SELECT
-struct lwip_sock;
+#include "esphome/core/lwip_fast_select.h"
 #endif
 
 namespace esphome::socket {
@@ -56,6 +56,15 @@ class BSDSocketImpl {
     return ::getsockopt(this->fd_, level, optname, optval, optlen);
   }
   int setsockopt(int level, int optname, const void *optval, socklen_t optlen) {
+#if defined(USE_LWIP_FAST_SELECT) && defined(CONFIG_LWIP_TCPIP_CORE_LOCKING)
+    // Fast path for TCP_NODELAY: directly set the pcb flag under the TCPIP core lock,
+    // bypassing lwip_setsockopt overhead (socket lookups, hook, switch cascade, refcounting).
+    if (level == IPPROTO_TCP && optname == TCP_NODELAY && optlen == sizeof(int) && optval != nullptr) {
+      LwIPLock lock;
+      if (esphome_lwip_set_nodelay(this->cached_sock_, *reinterpret_cast<const int *>(optval) != 0))
+        return 0;
+    }
+#endif
     return ::setsockopt(this->fd_, level, optname, optval, optlen);
   }
   int listen(int backlog) { return ::listen(this->fd_, backlog); }

esphome/components/socket/headers.h

@@ -51,6 +51,8 @@
 #define SO_REUSEADDR 0x0004 /* Allow local address reuse */
 #define SO_KEEPALIVE 0x0008 /* keep connections alive */
 #define SO_BROADCAST 0x0020 /* permit to send and to receive broadcast messages (see IP_SOF_BROADCAST option) */
+#define SO_RCVTIMEO 0x1006  /* receive timeout */
+#define SO_SNDTIMEO 0x1005  /* send timeout */
 
 #define SOL_SOCKET 0xfff /* options for socket level */
 

esphome/components/socket/lwip_raw_tcp_impl.cpp

@@ -5,6 +5,7 @@
 
 #include <cerrno>
 #include <cstring>
+#include <sys/time.h>
 
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
@@ -81,7 +82,9 @@ void socket_delay(uint32_t ms) {
     s_socket_woke = false;
     return;
   }
-  s_socket_woke = false;
+  // Don't clear s_socket_woke here — if an IRQ fires between the check above
+  // and the while loop below, the while condition sees it immediately. Clearing
+  // here would lose that wake and sleep until the timer fires.
   s_delay_expired = false;
   // Set a one-shot timer to wake us after the timeout.
   // add_alarm_in_ms returns >0 on success, 0 if time already passed, <0 on error.
@@ -99,6 +102,7 @@ void socket_delay(uint32_t ms) {
   // Cancel timer if we woke early (socket data arrived before timeout)
   if (!s_delay_expired)
     cancel_alarm(alarm);
+  s_socket_woke = false;  // consume the wake for next call
 }
 
 // No IRAM_ATTR equivalent needed: on RP2040, CYW43 async_context runs LWIP
@@ -138,13 +142,46 @@ static const char *const TAG = "socket.lwip";
 #define LWIP_LOG(msg, ...)
 #endif
 
+// Clear arg, recv, and err callbacks, then abort a connected PCB.
+// Only valid for full tcp_pcb (not tcp_pcb_listen).
+// Must be called before destroying the object that tcp_arg points to —
+// tcp_abort() triggers the err callback synchronously, which would
+// otherwise call back into a partially-destroyed object.
+// tcp_sent/tcp_poll are not cleared because this implementation
+// never registers them.
+static void pcb_detach_abort(struct tcp_pcb *pcb) {
+  tcp_arg(pcb, nullptr);
+  tcp_recv(pcb, nullptr);
+  tcp_err(pcb, nullptr);
+  tcp_abort(pcb);
+}
+
+// Clear arg, recv, and err callbacks, then gracefully close a connected PCB.
+// Only valid for full tcp_pcb (not tcp_pcb_listen).
+// After tcp_close(), the PCB remains alive during the TCP close handshake
+// (FIN_WAIT, TIME_WAIT states). Without clearing callbacks first, LWIP
+// would call recv/err on a destroyed socket object, corrupting the heap.
+// tcp_sent/tcp_poll are not cleared because this implementation
+// never registers them.
+// Returns ERR_OK on success; on failure the PCB is aborted instead.
+static err_t pcb_detach_close(struct tcp_pcb *pcb) {
+  tcp_arg(pcb, nullptr);
+  tcp_recv(pcb, nullptr);
+  tcp_err(pcb, nullptr);
+  err_t err = tcp_close(pcb);
+  if (err != ERR_OK) {
+    tcp_abort(pcb);
+  }
+  return err;
+}
+
 // ---- LWIPRawCommon methods ----
 
 LWIPRawCommon::~LWIPRawCommon() {
   LWIP_LOCK();
   if (this->pcb_ != nullptr) {
     LWIP_LOG("tcp_abort(%p)", this->pcb_);
-    tcp_abort(this->pcb_);
+    pcb_detach_abort(this->pcb_);
     this->pcb_ = nullptr;
   }
 }
@@ -222,15 +259,13 @@ int LWIPRawCommon::close() {
     return -1;
   }
   LWIP_LOG("tcp_close(%p)", this->pcb_);
-  err_t err = tcp_close(this->pcb_);
+  err_t err = pcb_detach_close(this->pcb_);
+  this->pcb_ = nullptr;
   if (err != ERR_OK) {
     LWIP_LOG("  -> err %d", err);
-    tcp_abort(this->pcb_);
-    this->pcb_ = nullptr;
     errno = err == ERR_MEM ? ENOMEM : EIO;
     return -1;
   }
-  this->pcb_ = nullptr;
   return 0;
 }
 
@@ -328,6 +363,18 @@ int LWIPRawCommon::getsockopt(int level, int optname, void *optval, socklen_t *o
     *optlen = 4;
     return 0;
   }
+  if (level == SOL_SOCKET && optname == SO_RCVTIMEO) {
+    if (*optlen < sizeof(struct timeval)) {
+      errno = EINVAL;
+      return -1;
+    }
+    uint32_t ms = this->recv_timeout_cs_ * 10;
+    auto *tv = reinterpret_cast<struct timeval *>(optval);
+    tv->tv_sec = ms / 1000;
+    tv->tv_usec = (ms % 1000) * 1000;
+    *optlen = sizeof(struct timeval);
+    return 0;
+  }
   if (level == IPPROTO_TCP && optname == TCP_NODELAY) {
     if (*optlen < 4) {
       errno = EINVAL;
@@ -357,6 +404,21 @@ int LWIPRawCommon::setsockopt(int level, int optname, const void *optval, sockle
     // to prevent warnings
     return 0;
   }
+  if (level == SOL_SOCKET && optname == SO_RCVTIMEO) {
+    if (optlen < sizeof(struct timeval)) {
+      errno = EINVAL;
+      return -1;
+    }
+    const auto *tv = reinterpret_cast<const struct timeval *>(optval);
+    uint32_t ms = tv->tv_sec * 1000 + tv->tv_usec / 1000;
+    uint32_t cs = (ms + 9) / 10;  // round up to nearest centisecond
+    this->recv_timeout_cs_ = cs > 255 ? 255 : static_cast<uint8_t>(cs);
+    return 0;
+  }
+  if (level == SOL_SOCKET && optname == SO_SNDTIMEO) {
+    // Raw TCP writes are non-blocking (tcp_write), so send timeout is a no-op.
+    return 0;
+  }
   if (level == IPPROTO_TCP && optname == TCP_NODELAY) {
     if (optlen != 4) {
       errno = EINVAL;
@@ -487,8 +549,25 @@ err_t LWIPRawImpl::recv_fn(struct pbuf *pb, err_t err) {
   return ERR_OK;
 }
 
-ssize_t LWIPRawImpl::read(void *buf, size_t len) {
-  LWIP_LOCK();
+void LWIPRawImpl::wait_for_data_() {
+  // Wait for data without holding LWIP_LOCK so recv_fn() can run on RP2040
+  // (needs async_context lock).
+  //
+  // Loop until data arrives, connection closes, or the full timeout elapses.
+  // socket_delay() may return early due to other sockets waking the global
+  // socket_wake() flag, so we re-enter for the remaining time.
+  uint32_t timeout_ms = this->recv_timeout_cs_ * 10;
+  uint32_t start = millis();
+  while (this->waiting_for_data_()) {
+    uint32_t elapsed = millis() - start;
+    if (elapsed >= timeout_ms)
+      break;
+    socket_delay(timeout_ms - elapsed);
+  }
+}
+
+ssize_t LWIPRawImpl::read_locked_(void *buf, size_t len) {
+  // Caller must hold LWIP_LOCK. Copies available data from rx_buf_ into buf.
   if (this->pcb_ == nullptr) {
     errno = ECONNRESET;
     return -1;
@@ -547,11 +626,26 @@ ssize_t LWIPRawImpl::read(void *buf, size_t len) {
   return read;
 }
 
+ssize_t LWIPRawImpl::read(void *buf, size_t len) {
+  // See waiting_for_data_() for safety of unlocked reads.
+  if (this->recv_timeout_cs_ > 0 && this->waiting_for_data_()) {
+    this->wait_for_data_();
+  }
+
+  LWIP_LOCK();
+  return this->read_locked_(buf, len);
+}
+
 ssize_t LWIPRawImpl::readv(const struct iovec *iov, int iovcnt) {
+  // See waiting_for_data_() for safety of unlocked reads.
+  if (this->recv_timeout_cs_ > 0 && this->waiting_for_data_()) {
+    this->wait_for_data_();
+  }
+
   LWIP_LOCK();  // Hold for entire scatter-gather operation
   ssize_t ret = 0;
   for (int i = 0; i < iovcnt; i++) {
-    ssize_t err = this->read(reinterpret_cast<uint8_t *>(iov[i].iov_base), iov[i].iov_len);
+    ssize_t err = this->read_locked_(reinterpret_cast<uint8_t *>(iov[i].iov_base), iov[i].iov_len);
     if (err == -1) {
       if (ret != 0) {
         // if we already read some don't return an error
@@ -673,13 +767,10 @@ ssize_t LWIPRawImpl::writev(const struct iovec *iov, int iovcnt) {
 LWIPRawListenImpl::~LWIPRawListenImpl() {
   LWIP_LOCK();
   // Abort any queued PCBs that were never accepted by the main loop.
-  // Clear the error callback first — tcp_abort triggers it, and we don't
-  // want s_queued_err_fn writing to slots during destruction.
   for (uint8_t i = 0; i < this->accepted_socket_count_; i++) {
     auto &entry = this->accepted_pcbs_[i];
     if (entry.pcb != nullptr) {
-      tcp_err(entry.pcb, nullptr);
-      tcp_abort(entry.pcb);
+      pcb_detach_abort(entry.pcb);
       entry.pcb = nullptr;
     }
     if (entry.rx_buf != nullptr) {
@@ -691,6 +782,10 @@ LWIPRawListenImpl::~LWIPRawListenImpl() {
   // Listen PCBs must use tcp_close(), not tcp_abort().
   // tcp_abandon() asserts pcb->state != LISTEN and would access
   // fields that don't exist in the smaller tcp_pcb_listen struct.
+  // Don't use pcb_detach_close() here — tcp_recv()/tcp_err() also access
+  // fields that only exist in the full tcp_pcb, not tcp_pcb_listen.
+  // tcp_close() on a listen PCB is synchronous (frees immediately),
+  // so there are no async callbacks to worry about.
   // Close here and null pcb_ so the base destructor skips tcp_abort.
   if (this->pcb_ != nullptr) {
     tcp_close(this->pcb_);

esphome/components/socket/lwip_raw_tcp_impl.h

@@ -57,6 +57,7 @@ class LWIPRawCommon {
   // instead use it for determining whether to call lwip_output
   bool nodelay_ = false;
   sa_family_t family_ = 0;
+  uint8_t recv_timeout_cs_ = 0;  // SO_RCVTIMEO in centiseconds (0 = no timeout, max 2.55s)
 };
 
 /// Connected socket implementation for LWIP raw TCP.
@@ -107,11 +108,8 @@ class LWIPRawImpl : public LWIPRawCommon {
       errno = ECONNRESET;
       return -1;
     }
-    if (blocking) {
-      // blocking operation not supported
-      errno = EINVAL;
-      return -1;
-    }
+    // Raw TCP doesn't use a blocking flag directly. Blocking behavior
+    // is provided by SO_RCVTIMEO which makes read() wait via socket_delay().
     return 0;
   }
   int loop() { return 0; }
@@ -122,6 +120,14 @@ class LWIPRawImpl : public LWIPRawCommon {
   static err_t s_recv_fn(void *arg, struct tcp_pcb *pcb, struct pbuf *pb, err_t err);
 
  protected:
+  // True when the socket could receive data but none has arrived yet.
+  // Safe to call without LWIP_LOCK — only null-checks pointers and reads a bool,
+  // all atomic on ARM/Xtensa. A stale value is harmless: the caller either does
+  // an unnecessary wait (stale true) or skips it (stale false), and the
+  // authoritative recheck happens under LWIP_LOCK afterward.
+  bool waiting_for_data_() const { return this->rx_buf_ == nullptr && !this->rx_closed_ && this->pcb_ != nullptr; }
+  void wait_for_data_();
+  ssize_t read_locked_(void *buf, size_t len);
   ssize_t internal_write_(const void *buf, size_t len);
   int internal_output_();
 

esphome/components/socket/lwip_sockets_impl.h

@@ -10,7 +10,7 @@
 #include "headers.h"
 
 #ifdef USE_LWIP_FAST_SELECT
-struct lwip_sock;
+#include "esphome/core/lwip_fast_select.h"
 #endif
 
 namespace esphome::socket {
@@ -52,6 +52,15 @@ class LwIPSocketImpl {
     return lwip_getsockopt(this->fd_, level, optname, optval, optlen);
   }
   int setsockopt(int level, int optname, const void *optval, socklen_t optlen) {
+#if defined(USE_LWIP_FAST_SELECT) && defined(CONFIG_LWIP_TCPIP_CORE_LOCKING)
+    // Fast path for TCP_NODELAY: directly set the pcb flag under the TCPIP core lock,
+    // bypassing lwip_setsockopt overhead (socket lookups, hook, switch cascade, refcounting).
+    if (level == IPPROTO_TCP && optname == TCP_NODELAY && optlen == sizeof(int) && optval != nullptr) {
+      LwIPLock lock;
+      if (esphome_lwip_set_nodelay(this->cached_sock_, *reinterpret_cast<const int *>(optval) != 0))
+        return 0;
+    }
+#endif
     return lwip_setsockopt(this->fd_, level, optname, optval, optlen);
   }
   int listen(int backlog) { return lwip_listen(this->fd_, backlog); }

esphome/components/template/text/template_text.h

@@ -24,23 +24,23 @@ class TemplateTextSaverBase {
 template<uint8_t SZ> class TextSaver : public TemplateTextSaverBase {
  public:
   bool save(const std::string &value) override {
-    int diff = value.compare(this->prev_);
-    if (diff != 0) {
-      // If string is bigger than the allocation, do not save it.
-      // We don't need to waste ram setting prev_value either.
-      int size = value.size();
-      if (size <= SZ) {
-        // Make it into a length prefixed thing
-        unsigned char temp[SZ + 1];
-        memcpy(temp + 1, value.c_str(), size);
-        // SZ should be pre checked at the schema level, it can't go past the char range.
-        temp[0] = ((unsigned char) size);
-        this->pref_.save(&temp);
-        this->prev_.assign(value);
-        return true;
-      }
+    if (value == this->prev_) {
+      return true;  // No change, nothing to save
     }
-    return false;
+    // If string is bigger than the allocation, do not save it.
+    // We don't need to waste ram setting prev_value either.
+    int size = value.size();
+    if (size > SZ) {
+      return false;
+    }
+    // Make it into a length prefixed thing
+    unsigned char temp[SZ + 1];
+    memcpy(temp + 1, value.c_str(), size);
+    // SZ should be pre checked at the schema level, it can't go past the char range.
+    temp[0] = ((unsigned char) size);
+    this->pref_.save(&temp);
+    this->prev_.assign(value);
+    return true;
   }
 
   // Make the preference object.  Fill the provided location with the saved data

esphome/components/template/water_heater/template_water_heater.cpp

@@ -26,6 +26,7 @@ water_heater::WaterHeaterTraits TemplateWaterHeater::traits() {
 
   if (!this->supported_modes_.empty()) {
     traits.set_supported_modes(this->supported_modes_);
+    traits.add_feature_flags(water_heater::WATER_HEATER_SUPPORTS_OPERATION_MODE);
   }
 
   traits.set_supports_current_temperature(true);

esphome/components/time/real_time_clock.cpp

@@ -88,16 +88,16 @@ void RealTimeClock::synchronize_epoch_(uint32_t epoch) {
   struct timeval timev {
     .tv_sec = static_cast<time_t>(epoch), .tv_usec = 0,
   };
+#ifdef USE_ESP8266
+  // ESP8266 settimeofday() requires tz to be nullptr
+  int ret = settimeofday(&timev, nullptr);
+#else
   struct timezone tz = {0, 0};
   int ret = settimeofday(&timev, &tz);
-  if (ret != 0 && errno == EINVAL) {
-    // Some ESP8266 frameworks abort when timezone parameter is not NULL
-    // while ESP32 expects it not to be NULL
-    ret = settimeofday(&timev, nullptr);
-  }
+#endif
 
   if (ret != 0) {
-    ESP_LOGW(TAG, "setimeofday() failed with code %d", ret);
+    ESP_LOGW(TAG, "settimeofday() failed with code %d", ret);
   }
 #endif
   auto time = this->now();

esphome/components/uart/uart_component_rp2040.cpp

@@ -105,15 +105,34 @@ void RP2040UartComponent::setup() {
     }
   }
 
+  // Determine which hardware UART to use. A pin that is not specified
+  // should not prevent hardware UART selection — one-way UART is valid.
+  // When both pins are configured, both must be HW-capable and agree on UART number.
+  // When only one pin is configured (nullptr other), use that pin's HW UART.
+  // If a pin is configured but not HW-capable (inverted/invalid), fall back to SerialPIO.
+  int8_t hw_uart = -1;
+  const bool tx_configured = (this->tx_pin_ != nullptr);
+  const bool rx_configured = (this->rx_pin_ != nullptr);
+
+  if (tx_configured && rx_configured) {
+    // Both pins configured — both must map to the same hardware UART
+    if (tx_hw != -1 && rx_hw != -1 && tx_hw == rx_hw) {
+      hw_uart = tx_hw;
+    }
+  } else if (tx_configured) {
+    hw_uart = tx_hw;
+  } else if (rx_configured) {
+    hw_uart = rx_hw;
+  }
+
 #ifdef USE_LOGGER
-  if (tx_hw == rx_hw && logger::global_logger->get_uart() == tx_hw) {
-    ESP_LOGD(TAG, "Using SerialPIO as UART%d is taken by the logger", tx_hw);
-    tx_hw = -1;
-    rx_hw = -1;
+  if (hw_uart != -1 && logger::global_logger->get_uart() == hw_uart) {
+    ESP_LOGD(TAG, "Using SerialPIO as UART%d is taken by the logger", hw_uart);
+    hw_uart = -1;
   }
 #endif
 
-  if (tx_hw == -1 || rx_hw == -1 || tx_hw != rx_hw) {
+  if (hw_uart == -1) {
     ESP_LOGV(TAG, "Using SerialPIO");
     pin_size_t tx = this->tx_pin_ == nullptr ? NOPIN : this->tx_pin_->get_pin();
     pin_size_t rx = this->rx_pin_ == nullptr ? NOPIN : this->rx_pin_->get_pin();
@@ -127,13 +146,15 @@ void RP2040UartComponent::setup() {
   } else {
     ESP_LOGV(TAG, "Using Hardware Serial");
     SerialUART *serial;
-    if (tx_hw == 0) {
+    if (hw_uart == 0) {
       serial = &Serial1;
     } else {
       serial = &Serial2;
     }
-    serial->setTX(this->tx_pin_->get_pin());
-    serial->setRX(this->rx_pin_->get_pin());
+    if (this->tx_pin_ != nullptr)
+      serial->setTX(this->tx_pin_->get_pin());
+    if (this->rx_pin_ != nullptr)
+      serial->setRX(this->rx_pin_->get_pin());
     serial->setFIFOSize(this->rx_buffer_size_);
     serial->begin(this->baud_rate_, config);
     this->serial_ = serial;

esphome/components/vbus/__init__.py

@@ -19,6 +19,7 @@ CONF_DELTASOL_BS_2009 = "deltasol_bs_2009"
 CONF_DELTASOL_BS2 = "deltasol_bs2"
 CONF_DELTASOL_C = "deltasol_c"
 CONF_DELTASOL_CS2 = "deltasol_cs2"
+CONF_DELTASOL_CS4 = "deltasol_cs4"
 CONF_DELTASOL_CS_PLUS = "deltasol_cs_plus"
 
 CONFIG_SCHEMA = uart.UART_DEVICE_SCHEMA.extend(

esphome/components/vbus/binary_sensor/__init__.py

@@ -20,6 +20,7 @@ from .. import (
     CONF_DELTASOL_BS_PLUS,
     CONF_DELTASOL_C,
     CONF_DELTASOL_CS2,
+    CONF_DELTASOL_CS4,
     CONF_DELTASOL_CS_PLUS,
     CONF_VBUS_ID,
     VBus,
@@ -31,6 +32,7 @@ DeltaSol_BS_2009 = vbus_ns.class_("DeltaSolBS2009BSensor", cg.Component)
 DeltaSol_BS2 = vbus_ns.class_("DeltaSolBS2BSensor", cg.Component)
 DeltaSol_C = vbus_ns.class_("DeltaSolCBSensor", cg.Component)
 DeltaSol_CS2 = vbus_ns.class_("DeltaSolCS2BSensor", cg.Component)
+DeltaSol_CS4 = vbus_ns.class_("DeltaSolCS4BSensor", cg.Component)
 DeltaSol_CS_Plus = vbus_ns.class_("DeltaSolCSPlusBSensor", cg.Component)
 VBusCustom = vbus_ns.class_("VBusCustomBSensor", cg.Component)
 VBusCustomSub = vbus_ns.class_("VBusCustomSubBSensor", cg.Component)
@@ -186,6 +188,28 @@ CONFIG_SCHEMA = cv.typed_schema(
                 ),
             }
         ),
+        CONF_DELTASOL_CS4: cv.COMPONENT_SCHEMA.extend(
+            {
+                cv.GenerateID(): cv.declare_id(DeltaSol_CS4),
+                cv.GenerateID(CONF_VBUS_ID): cv.use_id(VBus),
+                cv.Optional(CONF_SENSOR1_ERROR): binary_sensor.binary_sensor_schema(
+                    device_class=DEVICE_CLASS_PROBLEM,
+                    entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
+                ),
+                cv.Optional(CONF_SENSOR2_ERROR): binary_sensor.binary_sensor_schema(
+                    device_class=DEVICE_CLASS_PROBLEM,
+                    entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
+                ),
+                cv.Optional(CONF_SENSOR3_ERROR): binary_sensor.binary_sensor_schema(
+                    device_class=DEVICE_CLASS_PROBLEM,
+                    entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
+                ),
+                cv.Optional(CONF_SENSOR4_ERROR): binary_sensor.binary_sensor_schema(
+                    device_class=DEVICE_CLASS_PROBLEM,
+                    entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
+                ),
+            }
+        ),
         CONF_DELTASOL_CS_PLUS: cv.COMPONENT_SCHEMA.extend(
             {
                 cv.GenerateID(): cv.declare_id(DeltaSol_CS_Plus),
@@ -350,6 +374,23 @@ async def to_code(config):
             sens = await binary_sensor.new_binary_sensor(config[CONF_SENSOR4_ERROR])
             cg.add(var.set_s4_error_bsensor(sens))
 
+    elif config[CONF_MODEL] == CONF_DELTASOL_CS4:
+        cg.add(var.set_command(0x0100))
+        cg.add(var.set_source(0x1122))
+        cg.add(var.set_dest(0x0010))
+        if CONF_SENSOR1_ERROR in config:
+            sens = await binary_sensor.new_binary_sensor(config[CONF_SENSOR1_ERROR])
+            cg.add(var.set_s1_error_bsensor(sens))
+        if CONF_SENSOR2_ERROR in config:
+            sens = await binary_sensor.new_binary_sensor(config[CONF_SENSOR2_ERROR])
+            cg.add(var.set_s2_error_bsensor(sens))
+        if CONF_SENSOR3_ERROR in config:
+            sens = await binary_sensor.new_binary_sensor(config[CONF_SENSOR3_ERROR])
+            cg.add(var.set_s3_error_bsensor(sens))
+        if CONF_SENSOR4_ERROR in config:
+            sens = await binary_sensor.new_binary_sensor(config[CONF_SENSOR4_ERROR])
+            cg.add(var.set_s4_error_bsensor(sens))
+
     elif config[CONF_MODEL] == CONF_DELTASOL_CS_PLUS:
         cg.add(var.set_command(0x0100))
         cg.add(var.set_source(0x2211))

esphome/components/vbus/binary_sensor/vbus_binary_sensor.cpp

@@ -110,6 +110,25 @@ void DeltaSolCS2BSensor::handle_message(std::vector<uint8_t> &message) {
     this->s4_error_bsensor_->publish_state(message[18] & 8);
 }
 
+void DeltaSolCS4BSensor::dump_config() {
+  ESP_LOGCONFIG(TAG, "Deltasol CS4:");
+  LOG_BINARY_SENSOR("  ", "Sensor 1 Error", this->s1_error_bsensor_);
+  LOG_BINARY_SENSOR("  ", "Sensor 2 Error", this->s2_error_bsensor_);
+  LOG_BINARY_SENSOR("  ", "Sensor 3 Error", this->s3_error_bsensor_);
+  LOG_BINARY_SENSOR("  ", "Sensor 4 Error", this->s4_error_bsensor_);
+}
+
+void DeltaSolCS4BSensor::handle_message(std::vector<uint8_t> &message) {
+  if (this->s1_error_bsensor_ != nullptr)
+    this->s1_error_bsensor_->publish_state(message[20] & 1);
+  if (this->s2_error_bsensor_ != nullptr)
+    this->s2_error_bsensor_->publish_state(message[20] & 2);
+  if (this->s3_error_bsensor_ != nullptr)
+    this->s3_error_bsensor_->publish_state(message[20] & 4);
+  if (this->s4_error_bsensor_ != nullptr)
+    this->s4_error_bsensor_->publish_state(message[20] & 8);
+}
+
 void DeltaSolCSPlusBSensor::dump_config() {
   ESP_LOGCONFIG(TAG, "Deltasol CS Plus:");
   LOG_BINARY_SENSOR("  ", "Sensor 1 Error", this->s1_error_bsensor_);

esphome/components/vbus/binary_sensor/vbus_binary_sensor.h

@@ -94,6 +94,23 @@ class DeltaSolCS2BSensor : public VBusListener, public Component {
   void handle_message(std::vector<uint8_t> &message) override;
 };
 
+class DeltaSolCS4BSensor : public VBusListener, public Component {
+ public:
+  void dump_config() override;
+  void set_s1_error_bsensor(binary_sensor::BinarySensor *bsensor) { this->s1_error_bsensor_ = bsensor; }
+  void set_s2_error_bsensor(binary_sensor::BinarySensor *bsensor) { this->s2_error_bsensor_ = bsensor; }
+  void set_s3_error_bsensor(binary_sensor::BinarySensor *bsensor) { this->s3_error_bsensor_ = bsensor; }
+  void set_s4_error_bsensor(binary_sensor::BinarySensor *bsensor) { this->s4_error_bsensor_ = bsensor; }
+
+ protected:
+  binary_sensor::BinarySensor *s1_error_bsensor_{nullptr};
+  binary_sensor::BinarySensor *s2_error_bsensor_{nullptr};
+  binary_sensor::BinarySensor *s3_error_bsensor_{nullptr};
+  binary_sensor::BinarySensor *s4_error_bsensor_{nullptr};
+
+  void handle_message(std::vector<uint8_t> &message) override;
+};
+
 class DeltaSolCSPlusBSensor : public VBusListener, public Component {
  public:
   void dump_config() override;

esphome/components/vbus/sensor/__init__.py

@@ -36,6 +36,7 @@ from .. import (
     CONF_DELTASOL_BS_PLUS,
     CONF_DELTASOL_C,
     CONF_DELTASOL_CS2,
+    CONF_DELTASOL_CS4,
     CONF_DELTASOL_CS_PLUS,
     CONF_VBUS_ID,
     VBus,
@@ -47,6 +48,7 @@ DeltaSol_BS_2009 = vbus_ns.class_("DeltaSolBS2009Sensor", cg.Component)
 DeltaSol_BS2 = vbus_ns.class_("DeltaSolBS2Sensor", cg.Component)
 DeltaSol_C = vbus_ns.class_("DeltaSolCSensor", cg.Component)
 DeltaSol_CS2 = vbus_ns.class_("DeltaSolCS2Sensor", cg.Component)
+DeltaSol_CS4 = vbus_ns.class_("DeltaSolCS4Sensor", cg.Component)
 DeltaSol_CS_Plus = vbus_ns.class_("DeltaSolCSPlusSensor", cg.Component)
 VBusCustom = vbus_ns.class_("VBusCustomSensor", cg.Component)
 VBusCustomSub = vbus_ns.class_("VBusCustomSubSensor", cg.Component)
@@ -438,6 +440,99 @@ CONFIG_SCHEMA = cv.typed_schema(
                 ),
             }
         ),
+        CONF_DELTASOL_CS4: cv.COMPONENT_SCHEMA.extend(
+            {
+                cv.GenerateID(): cv.declare_id(DeltaSol_CS4),
+                cv.GenerateID(CONF_VBUS_ID): cv.use_id(VBus),
+                cv.Optional(CONF_TEMPERATURE_1): sensor.sensor_schema(
+                    unit_of_measurement=UNIT_CELSIUS,
+                    icon=ICON_THERMOMETER,
+                    accuracy_decimals=1,
+                    device_class=DEVICE_CLASS_TEMPERATURE,
+                    state_class=STATE_CLASS_MEASUREMENT,
+                ),
+                cv.Optional(CONF_TEMPERATURE_2): sensor.sensor_schema(
+                    unit_of_measurement=UNIT_CELSIUS,
+                    icon=ICON_THERMOMETER,
+                    accuracy_decimals=1,
+                    device_class=DEVICE_CLASS_TEMPERATURE,
+                    state_class=STATE_CLASS_MEASUREMENT,
+                ),
+                cv.Optional(CONF_TEMPERATURE_3): sensor.sensor_schema(
+                    unit_of_measurement=UNIT_CELSIUS,
+                    icon=ICON_THERMOMETER,
+                    accuracy_decimals=1,
+                    device_class=DEVICE_CLASS_TEMPERATURE,
+                    state_class=STATE_CLASS_MEASUREMENT,
+                ),
+                cv.Optional(CONF_TEMPERATURE_4): sensor.sensor_schema(
+                    unit_of_measurement=UNIT_CELSIUS,
+                    icon=ICON_THERMOMETER,
+                    accuracy_decimals=1,
+                    device_class=DEVICE_CLASS_TEMPERATURE,
+                    state_class=STATE_CLASS_MEASUREMENT,
+                ),
+                cv.Optional(CONF_TEMPERATURE_5): sensor.sensor_schema(
+                    unit_of_measurement=UNIT_CELSIUS,
+                    icon=ICON_THERMOMETER,
+                    accuracy_decimals=1,
+                    device_class=DEVICE_CLASS_TEMPERATURE,
+                    state_class=STATE_CLASS_MEASUREMENT,
+                ),
+                cv.Optional(CONF_PUMP_SPEED_1): sensor.sensor_schema(
+                    unit_of_measurement=UNIT_PERCENT,
+                    icon=ICON_PERCENT,
+                    accuracy_decimals=0,
+                    device_class=DEVICE_CLASS_EMPTY,
+                    state_class=STATE_CLASS_MEASUREMENT,
+                ),
+                cv.Optional(CONF_PUMP_SPEED_2): sensor.sensor_schema(
+                    unit_of_measurement=UNIT_PERCENT,
+                    icon=ICON_PERCENT,
+                    accuracy_decimals=0,
+                    device_class=DEVICE_CLASS_EMPTY,
+                    state_class=STATE_CLASS_MEASUREMENT,
+                ),
+                cv.Optional(CONF_OPERATING_HOURS_1): sensor.sensor_schema(
+                    unit_of_measurement=UNIT_HOUR,
+                    icon=ICON_TIMER,
+                    accuracy_decimals=0,
+                    device_class=DEVICE_CLASS_DURATION,
+                    state_class=STATE_CLASS_MEASUREMENT,
+                ),
+                cv.Optional(CONF_OPERATING_HOURS_2): sensor.sensor_schema(
+                    unit_of_measurement=UNIT_HOUR,
+                    icon=ICON_TIMER,
+                    accuracy_decimals=0,
+                    device_class=DEVICE_CLASS_DURATION,
+                    state_class=STATE_CLASS_MEASUREMENT,
+                ),
+                cv.Optional(CONF_HEAT_QUANTITY): sensor.sensor_schema(
+                    unit_of_measurement=UNIT_WATT_HOURS,
+                    icon=ICON_RADIATOR,
+                    accuracy_decimals=0,
+                    device_class=DEVICE_CLASS_ENERGY,
+                    state_class=STATE_CLASS_TOTAL_INCREASING,
+                ),
+                cv.Optional(CONF_TIME): sensor.sensor_schema(
+                    unit_of_measurement=UNIT_MINUTE,
+                    icon=ICON_TIMER,
+                    accuracy_decimals=0,
+                    device_class=DEVICE_CLASS_DURATION,
+                    state_class=STATE_CLASS_MEASUREMENT,
+                    entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
+                ),
+                cv.Optional(CONF_VERSION): sensor.sensor_schema(
+                    accuracy_decimals=2,
+                    entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
+                ),
+                cv.Optional(CONF_FLOW_RATE): sensor.sensor_schema(
+                    accuracy_decimals=0,
+                    device_class=DEVICE_CLASS_EMPTY,
+                    state_class=STATE_CLASS_MEASUREMENT,
+                ),
+            }
+        ),
         CONF_DELTASOL_CS_PLUS: cv.COMPONENT_SCHEMA.extend(
             {
                 cv.GenerateID(): cv.declare_id(DeltaSol_CS_Plus),
@@ -734,7 +829,51 @@ async def to_code(config):
             sens = await sensor.new_sensor(config[CONF_VERSION])
             cg.add(var.set_version_sensor(sens))
 
-    if config[CONF_MODEL] == CONF_DELTASOL_CS_PLUS:
+    elif config[CONF_MODEL] == CONF_DELTASOL_CS4:
+        cg.add(var.set_command(0x0100))
+        cg.add(var.set_source(0x1122))
+        cg.add(var.set_dest(0x0010))
+        if CONF_TEMPERATURE_1 in config:
+            sens = await sensor.new_sensor(config[CONF_TEMPERATURE_1])
+            cg.add(var.set_temperature1_sensor(sens))
+        if CONF_TEMPERATURE_2 in config:
+            sens = await sensor.new_sensor(config[CONF_TEMPERATURE_2])
+            cg.add(var.set_temperature2_sensor(sens))
+        if CONF_TEMPERATURE_3 in config:
+            sens = await sensor.new_sensor(config[CONF_TEMPERATURE_3])
+            cg.add(var.set_temperature3_sensor(sens))
+        if CONF_TEMPERATURE_4 in config:
+            sens = await sensor.new_sensor(config[CONF_TEMPERATURE_4])
+            cg.add(var.set_temperature4_sensor(sens))
+        if CONF_TEMPERATURE_5 in config:
+            sens = await sensor.new_sensor(config[CONF_TEMPERATURE_5])
+            cg.add(var.set_temperature5_sensor(sens))
+        if CONF_PUMP_SPEED_1 in config:
+            sens = await sensor.new_sensor(config[CONF_PUMP_SPEED_1])
+            cg.add(var.set_pump_speed1_sensor(sens))
+        if CONF_PUMP_SPEED_2 in config:
+            sens = await sensor.new_sensor(config[CONF_PUMP_SPEED_2])
+            cg.add(var.set_pump_speed2_sensor(sens))
+        if CONF_OPERATING_HOURS_1 in config:
+            sens = await sensor.new_sensor(config[CONF_OPERATING_HOURS_1])
+            cg.add(var.set_operating_hours1_sensor(sens))
+        if CONF_OPERATING_HOURS_2 in config:
+            sens = await sensor.new_sensor(config[CONF_OPERATING_HOURS_2])
+            cg.add(var.set_operating_hours2_sensor(sens))
+        if CONF_HEAT_QUANTITY in config:
+            sens = await sensor.new_sensor(config[CONF_HEAT_QUANTITY])
+            cg.add(var.set_heat_quantity_sensor(sens))
+        if CONF_TIME in config:
+            sens = await sensor.new_sensor(config[CONF_TIME])
+            cg.add(var.set_time_sensor(sens))
+        if CONF_VERSION in config:
+            sens = await sensor.new_sensor(config[CONF_VERSION])
+            cg.add(var.set_version_sensor(sens))
+        if CONF_FLOW_RATE in config:
+            sens = await sensor.new_sensor(config[CONF_FLOW_RATE])
+            cg.add(var.set_flow_rate_sensor(sens))
+
+    elif config[CONF_MODEL] == CONF_DELTASOL_CS_PLUS:
         cg.add(var.set_command(0x0100))
         cg.add(var.set_source(0x2211))
         cg.add(var.set_dest(0x0010))

esphome/components/vbus/sensor/vbus_sensor.cpp

@@ -168,6 +168,52 @@ void DeltaSolCS2Sensor::handle_message(std::vector<uint8_t> &message) {
     this->version_sensor_->publish_state(get_u16(message, 28) * 0.01f);
 }
 
+void DeltaSolCS4Sensor::dump_config() {
+  ESP_LOGCONFIG(TAG, "Deltasol CS4:");
+  LOG_SENSOR("  ", "Temperature 1", this->temperature1_sensor_);
+  LOG_SENSOR("  ", "Temperature 2", this->temperature2_sensor_);
+  LOG_SENSOR("  ", "Temperature 3", this->temperature3_sensor_);
+  LOG_SENSOR("  ", "Temperature 4", this->temperature4_sensor_);
+  LOG_SENSOR("  ", "Temperature 5", this->temperature5_sensor_);
+  LOG_SENSOR("  ", "Pump Speed 1", this->pump_speed1_sensor_);
+  LOG_SENSOR("  ", "Pump Speed 2", this->pump_speed2_sensor_);
+  LOG_SENSOR("  ", "Operating Hours 1", this->operating_hours1_sensor_);
+  LOG_SENSOR("  ", "Operating Hours 2", this->operating_hours2_sensor_);
+  LOG_SENSOR("  ", "Heat Quantity", this->heat_quantity_sensor_);
+  LOG_SENSOR("  ", "System Time", this->time_sensor_);
+  LOG_SENSOR("  ", "FW Version", this->version_sensor_);
+  LOG_SENSOR("  ", "Flow Rate", this->flow_rate_sensor_);
+}
+
+void DeltaSolCS4Sensor::handle_message(std::vector<uint8_t> &message) {
+  if (this->temperature1_sensor_ != nullptr)
+    this->temperature1_sensor_->publish_state(get_i16(message, 0) * 0.1f);
+  if (this->temperature2_sensor_ != nullptr)
+    this->temperature2_sensor_->publish_state(get_i16(message, 2) * 0.1f);
+  if (this->temperature3_sensor_ != nullptr)
+    this->temperature3_sensor_->publish_state(get_i16(message, 4) * 0.1f);
+  if (this->temperature4_sensor_ != nullptr)
+    this->temperature4_sensor_->publish_state(get_i16(message, 6) * 0.1f);
+  if (this->temperature5_sensor_ != nullptr)
+    this->temperature5_sensor_->publish_state(get_i16(message, 36) * 0.1f);
+  if (this->pump_speed1_sensor_ != nullptr)
+    this->pump_speed1_sensor_->publish_state(message[8]);
+  if (this->pump_speed2_sensor_ != nullptr)
+    this->pump_speed2_sensor_->publish_state(message[12]);
+  if (this->operating_hours1_sensor_ != nullptr)
+    this->operating_hours1_sensor_->publish_state(get_u16(message, 10));
+  if (this->operating_hours2_sensor_ != nullptr)
+    this->operating_hours2_sensor_->publish_state(get_u16(message, 14));
+  if (this->heat_quantity_sensor_ != nullptr)
+    this->heat_quantity_sensor_->publish_state((get_u16(message, 30) << 16) + get_u16(message, 28));
+  if (this->time_sensor_ != nullptr)
+    this->time_sensor_->publish_state(get_u16(message, 22));
+  if (this->version_sensor_ != nullptr)
+    this->version_sensor_->publish_state(get_u16(message, 32) * 0.01f);
+  if (this->flow_rate_sensor_ != nullptr)
+    this->flow_rate_sensor_->publish_state(get_u16(message, 38));
+}
+
 void DeltaSolCSPlusSensor::dump_config() {
   ESP_LOGCONFIG(TAG, "Deltasol CS Plus:");
   LOG_SENSOR("  ", "Temperature 1", this->temperature1_sensor_);

esphome/components/vbus/sensor/vbus_sensor.h

@@ -122,6 +122,41 @@ class DeltaSolCS2Sensor : public VBusListener, public Component {
   void handle_message(std::vector<uint8_t> &message) override;
 };
 
+class DeltaSolCS4Sensor : public VBusListener, public Component {
+ public:
+  void dump_config() override;
+  void set_temperature1_sensor(sensor::Sensor *sensor) { this->temperature1_sensor_ = sensor; }
+  void set_temperature2_sensor(sensor::Sensor *sensor) { this->temperature2_sensor_ = sensor; }
+  void set_temperature3_sensor(sensor::Sensor *sensor) { this->temperature3_sensor_ = sensor; }
+  void set_temperature4_sensor(sensor::Sensor *sensor) { this->temperature4_sensor_ = sensor; }
+  void set_temperature5_sensor(sensor::Sensor *sensor) { this->temperature5_sensor_ = sensor; }
+  void set_pump_speed1_sensor(sensor::Sensor *sensor) { this->pump_speed1_sensor_ = sensor; }
+  void set_pump_speed2_sensor(sensor::Sensor *sensor) { this->pump_speed2_sensor_ = sensor; }
+  void set_operating_hours1_sensor(sensor::Sensor *sensor) { this->operating_hours1_sensor_ = sensor; }
+  void set_operating_hours2_sensor(sensor::Sensor *sensor) { this->operating_hours2_sensor_ = sensor; }
+  void set_heat_quantity_sensor(sensor::Sensor *sensor) { this->heat_quantity_sensor_ = sensor; }
+  void set_time_sensor(sensor::Sensor *sensor) { this->time_sensor_ = sensor; }
+  void set_version_sensor(sensor::Sensor *sensor) { this->version_sensor_ = sensor; }
+  void set_flow_rate_sensor(sensor::Sensor *sensor) { this->flow_rate_sensor_ = sensor; }
+
+ protected:
+  sensor::Sensor *temperature1_sensor_{nullptr};
+  sensor::Sensor *temperature2_sensor_{nullptr};
+  sensor::Sensor *temperature3_sensor_{nullptr};
+  sensor::Sensor *temperature4_sensor_{nullptr};
+  sensor::Sensor *temperature5_sensor_{nullptr};
+  sensor::Sensor *pump_speed1_sensor_{nullptr};
+  sensor::Sensor *pump_speed2_sensor_{nullptr};
+  sensor::Sensor *operating_hours1_sensor_{nullptr};
+  sensor::Sensor *operating_hours2_sensor_{nullptr};
+  sensor::Sensor *heat_quantity_sensor_{nullptr};
+  sensor::Sensor *time_sensor_{nullptr};
+  sensor::Sensor *version_sensor_{nullptr};
+  sensor::Sensor *flow_rate_sensor_{nullptr};
+
+  void handle_message(std::vector<uint8_t> &message) override;
+};
+
 class DeltaSolCSPlusSensor : public VBusListener, public Component {
  public:
   void dump_config() override;

esphome/components/web_server/web_server.cpp

@@ -2181,7 +2181,7 @@ json::SerializationBuffer<> WebServer::update_state_json_generator(WebServer *we
 }
 json::SerializationBuffer<> WebServer::update_all_json_generator(WebServer *web_server, void *source) {
   // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-  return web_server->update_json_((update::UpdateEntity *) (source), DETAIL_STATE);
+  return web_server->update_json_((update::UpdateEntity *) (source), DETAIL_ALL);
 }
 json::SerializationBuffer<> WebServer::update_json_(update::UpdateEntity *obj, JsonDetail start_config) {
   // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson

esphome/components/web_server_base/web_server_base.cpp

@@ -11,6 +11,10 @@ void WebServerBase::add_handler(AsyncWebHandler *handler) {
     handler = new internal::AuthMiddlewareHandler(handler, &credentials_);
   }
 #endif
+  this->add_handler_without_auth(handler);
+}
+
+void WebServerBase::add_handler_without_auth(AsyncWebHandler *handler) {
   this->handlers_.push_back(handler);
   if (this->server_ != nullptr) {
     this->server_->addHandler(handler);

esphome/components/web_server_base/web_server_base.h

@@ -122,6 +122,14 @@ class WebServerBase {
 #endif
 
   void add_handler(AsyncWebHandler *handler);
+  /**
+   * WARNING: Registers a handler that bypasses the USE_WEBSERVER_AUTH middleware.
+   *
+   * This should only be used for endpoints that are intentionally unauthenticated
+   * (for example, captive portal or very limited-status endpoints). For normal
+   * endpoints that should respect web server authentication, use add_handler().
+   */
+  void add_handler_without_auth(AsyncWebHandler *handler);
 
   void set_port(uint16_t port) { port_ = port; }
   uint16_t get_port() const { return port_; }

esphome/components/wifi/__init__.py

@@ -166,6 +166,7 @@ TTLS_PHASE_2 = {
 }
 
 EAP_AUTH_SCHEMA = cv.All(
+    cv.only_on([Platform.ESP32, Platform.ESP8266]),
     cv.Schema(
         {
             cv.Optional(CONF_IDENTITY): cv.string_strict,
@@ -562,13 +563,6 @@ async def to_code(config):
         cg.add_library("ESP8266WiFi", None)
     elif CORE.is_rp2040:
         cg.add_library("WiFi", None)
-        # RP2040's mDNS library (LEAmDNS) relies on LwipIntf::stateUpCB() to restart
-        # mDNS when the network interface reconnects. However, this callback is disabled
-        # in the arduino-pico framework. As a workaround, we block component setup until
-        # WiFi is connected via can_proceed(), ensuring mDNS.begin() is called with an
-        # active connection. This define enables the loop priority sorting infrastructure
-        # used during the setup blocking phase.
-        cg.add_define("USE_LOOP_PRIORITY")
 
     if CORE.is_esp32:
         if config[CONF_ENABLE_BTM] or config[CONF_ENABLE_RRM]:

esphome/components/wifi/wifi_component.cpp

@@ -6,7 +6,7 @@
 #include <type_traits>
 
 #ifdef USE_ESP32
-#if (ESP_IDF_VERSION_MAJOR >= 5 && ESP_IDF_VERSION_MINOR >= 1)
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
 #include <esp_eap_client.h>
 #else
 #include <esp_wpa2.h>
@@ -2109,20 +2109,6 @@ void WiFiComponent::retry_connect() {
   }
 }
 
-#ifdef USE_RP2040
-// RP2040's mDNS library (LEAmDNS) relies on LwipIntf::stateUpCB() to restart
-// mDNS when the network interface reconnects. However, this callback is disabled
-// in the arduino-pico framework. As a workaround, we block component setup until
-// WiFi is connected, ensuring mDNS.begin() is called with an active connection.
-
-bool WiFiComponent::can_proceed() {
-  if (!this->has_sta() || this->state_ == WIFI_COMPONENT_STATE_DISABLED || this->ap_setup_) {
-    return true;
-  }
-  return this->is_connected_();
-}
-#endif
-
 void WiFiComponent::set_reboot_timeout(uint32_t reboot_timeout) { this->reboot_timeout_ = reboot_timeout; }
 bool WiFiComponent::is_connected_() const {
   return this->state_ == WIFI_COMPONENT_STATE_STA_CONNECTED &&

esphome/components/wifi/wifi_component.h

@@ -18,7 +18,7 @@
 #endif
 
 #if defined(USE_ESP32) && defined(USE_WIFI_WPA2_EAP)
-#if (ESP_IDF_VERSION_MAJOR >= 5) && (ESP_IDF_VERSION_MINOR >= 1)
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
 #include <esp_eap_client.h>
 #else
 #include <esp_wpa2.h>
@@ -437,10 +437,6 @@ class WiFiComponent : public Component {
 
   void retry_connect();
 
-#ifdef USE_RP2040
-  bool can_proceed() override;
-#endif
-
   void set_reboot_timeout(uint32_t reboot_timeout);
 
   bool is_connected() const { return this->connected_; }

esphome/components/wifi/wifi_component_esp_idf.cpp

@@ -17,7 +17,7 @@
 #include <memory>
 #include <utility>
 #ifdef USE_WIFI_WPA2_EAP
-#if (ESP_IDF_VERSION_MAJOR >= 5) && (ESP_IDF_VERSION_MINOR >= 1)
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
 #include <esp_eap_client.h>
 #else
 #include <esp_wpa2.h>
@@ -75,7 +75,11 @@ struct IDFWiFiEvent {
 #if USE_NETWORK_IPV6
     ip_event_got_ip6_t ip_got_ip6;
 #endif /* USE_NETWORK_IPV6 */
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(6, 0, 0)
+    ip_event_assigned_ip_to_client_t ip_assigned_ip_to_client;
+#else
     ip_event_ap_staipassigned_t ip_ap_staipassigned;
+#endif
   } data;
 };
 
@@ -116,8 +120,13 @@ void event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, voi
     memcpy(&event.data.ap_staconnected, event_data, sizeof(wifi_event_ap_staconnected_t));
   } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_AP_STADISCONNECTED) {
     memcpy(&event.data.ap_stadisconnected, event_data, sizeof(wifi_event_ap_stadisconnected_t));
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(6, 0, 0)
+  } else if (event_base == IP_EVENT && event_id == IP_EVENT_ASSIGNED_IP_TO_CLIENT) {
+    memcpy(&event.data.ip_assigned_ip_to_client, event_data, sizeof(ip_event_assigned_ip_to_client_t));
+#else
   } else if (event_base == IP_EVENT && event_id == IP_EVENT_AP_STAIPASSIGNED) {
     memcpy(&event.data.ip_ap_staipassigned, event_data, sizeof(ip_event_ap_staipassigned_t));
+#endif
   } else {
     // did not match any event, don't send anything
     return;
@@ -407,7 +416,7 @@ bool WiFiComponent::wifi_sta_connect_(const WiFiAP &ap) {
   if (eap_opt.has_value()) {
     // note: all certificates and keys have to be null terminated. Lengths are appended by +1 to include \0.
     EAPAuth eap = *eap_opt;
-#if (ESP_IDF_VERSION_MAJOR >= 5) && (ESP_IDF_VERSION_MINOR >= 1)
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
     err = esp_eap_client_set_identity((uint8_t *) eap.identity.c_str(), eap.identity.length());
 #else
     err = esp_wifi_sta_wpa2_ent_set_identity((uint8_t *) eap.identity.c_str(), eap.identity.length());
@@ -419,7 +428,7 @@ bool WiFiComponent::wifi_sta_connect_(const WiFiAP &ap) {
     int client_cert_len = strlen(eap.client_cert);
     int client_key_len = strlen(eap.client_key);
     if (ca_cert_len) {
-#if (ESP_IDF_VERSION_MAJOR >= 5) && (ESP_IDF_VERSION_MINOR >= 1)
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
       err = esp_eap_client_set_ca_cert((uint8_t *) eap.ca_cert, ca_cert_len + 1);
 #else
       err = esp_wifi_sta_wpa2_ent_set_ca_cert((uint8_t *) eap.ca_cert, ca_cert_len + 1);
@@ -432,7 +441,7 @@ bool WiFiComponent::wifi_sta_connect_(const WiFiAP &ap) {
     // validation is not required as the config tool has already validated it
     if (client_cert_len && client_key_len) {
       // if we have certs, this must be EAP-TLS
-#if (ESP_IDF_VERSION_MAJOR >= 5) && (ESP_IDF_VERSION_MINOR >= 1)
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
       err = esp_eap_client_set_certificate_and_key((uint8_t *) eap.client_cert, client_cert_len + 1,
                                                    (uint8_t *) eap.client_key, client_key_len + 1,
                                                    (uint8_t *) eap.password.c_str(), eap.password.length());
@@ -446,7 +455,7 @@ bool WiFiComponent::wifi_sta_connect_(const WiFiAP &ap) {
       }
     } else {
       // in the absence of certs, assume this is username/password based
-#if (ESP_IDF_VERSION_MAJOR >= 5) && (ESP_IDF_VERSION_MINOR >= 1)
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
       err = esp_eap_client_set_username((uint8_t *) eap.username.c_str(), eap.username.length());
 #else
       err = esp_wifi_sta_wpa2_ent_set_username((uint8_t *) eap.username.c_str(), eap.username.length());
@@ -454,7 +463,7 @@ bool WiFiComponent::wifi_sta_connect_(const WiFiAP &ap) {
       if (err != ESP_OK) {
         ESP_LOGV(TAG, "set_username failed %d", err);
       }
-#if (ESP_IDF_VERSION_MAJOR >= 5) && (ESP_IDF_VERSION_MINOR >= 1)
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
       err = esp_eap_client_set_password((uint8_t *) eap.password.c_str(), eap.password.length());
 #else
       err = esp_wifi_sta_wpa2_ent_set_password((uint8_t *) eap.password.c_str(), eap.password.length());
@@ -463,7 +472,7 @@ bool WiFiComponent::wifi_sta_connect_(const WiFiAP &ap) {
         ESP_LOGV(TAG, "set_password failed %d", err);
       }
       // set TTLS Phase 2, defaults to MSCHAPV2
-#if (ESP_IDF_VERSION_MAJOR >= 5) && (ESP_IDF_VERSION_MINOR >= 1)
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
       err = esp_eap_client_set_ttls_phase2_method(eap.ttls_phase_2);
 #else
       err = esp_wifi_sta_wpa2_ent_set_ttls_phase2_method(eap.ttls_phase_2);
@@ -472,7 +481,7 @@ bool WiFiComponent::wifi_sta_connect_(const WiFiAP &ap) {
         ESP_LOGV(TAG, "set_ttls_phase2_method failed %d", err);
       }
     }
-#if (ESP_IDF_VERSION_MAJOR >= 5) && (ESP_IDF_VERSION_MINOR >= 1)
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
     err = esp_wifi_sta_enterprise_enable();
 #else
     err = esp_wifi_sta_wpa2_ent_enable();
@@ -628,14 +637,26 @@ const char *get_disconnect_reason_str(uint8_t reason) {
       return "Auth Expired";
     case WIFI_REASON_AUTH_LEAVE:
       return "Auth Leave";
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(6, 0, 0)
+    case WIFI_REASON_DISASSOC_DUE_TO_INACTIVITY:
+      return "Disassociated Due to Inactivity";
+#else
     case WIFI_REASON_ASSOC_EXPIRE:
       return "Association Expired";
+#endif
     case WIFI_REASON_ASSOC_TOOMANY:
       return "Too Many Associations";
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(6, 0, 0)
+    case WIFI_REASON_CLASS2_FRAME_FROM_NONAUTH_STA:
+      return "Class 2 Frame from Non-Authenticated STA";
+    case WIFI_REASON_CLASS3_FRAME_FROM_NONASSOC_STA:
+      return "Class 3 Frame from Non-Associated STA";
+#else
     case WIFI_REASON_NOT_AUTHED:
       return "Not Authenticated";
     case WIFI_REASON_NOT_ASSOCED:
       return "Not Associated";
+#endif
     case WIFI_REASON_ASSOC_LEAVE:
       return "Association Leave";
     case WIFI_REASON_ASSOC_NOT_AUTHED:
@@ -688,7 +709,7 @@ const char *get_disconnect_reason_str(uint8_t reason) {
       return "Association comeback time too long";
     case WIFI_REASON_SA_QUERY_TIMEOUT:
       return "SA query timeout";
-#if (ESP_IDF_VERSION_MAJOR >= 5) && (ESP_IDF_VERSION_MINOR >= 2)
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 2, 0)
     case WIFI_REASON_NO_AP_FOUND_W_COMPATIBLE_SECURITY:
       return "No AP found with compatible security";
     case WIFI_REASON_NO_AP_FOUND_IN_AUTHMODE_THRESHOLD:
@@ -917,8 +938,13 @@ void WiFiComponent::wifi_process_event_(IDFWiFiEvent *data) {
     ESP_LOGV(TAG, "AP client disconnected MAC=%s", mac_buf);
 #endif
 
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(6, 0, 0)
+  } else if (data->event_base == IP_EVENT && data->event_id == IP_EVENT_ASSIGNED_IP_TO_CLIENT) {
+    const auto &it = data->data.ip_assigned_ip_to_client;
+#else
   } else if (data->event_base == IP_EVENT && data->event_id == IP_EVENT_AP_STAIPASSIGNED) {
     const auto &it = data->data.ip_ap_staipassigned;
+#endif
     ESP_LOGV(TAG, "AP client assigned IP " IPSTR, IP2STR(&it.ip));
   }
 }

esphome/const.py

@@ -4,7 +4,7 @@ from enum import Enum
 
 from esphome.enum import StrEnum
 
-__version__ = "2026.3.0b1"
+__version__ = "2026.4.0-dev"
 
 ALLOWED_NAME_CHARS = "abcdefghijklmnopqrstuvwxyz0123456789-_"
 VALID_SUBSTITUTIONS_CHARACTERS = (
@@ -1235,6 +1235,7 @@ UNIT_LITRE = "L"
 UNIT_LUX = "lx"
 UNIT_MEGAJOULE = "MJ"
 UNIT_METER = "m"
+UNIT_METER_PER_SECOND = "m/s"
 UNIT_METER_PER_SECOND_SQUARED = "m/s²"
 UNIT_MICROAMP = "µA"
 UNIT_MICROGRAMS_PER_CUBIC_METER = "µg/m³"
@@ -1244,6 +1245,7 @@ UNIT_MICROSILVERTS_PER_HOUR = "µSv/h"
 UNIT_MICROTESLA = "µT"
 UNIT_MILLIAMP = "mA"
 UNIT_MILLIGRAMS_PER_CUBIC_METER = "mg/m³"
+UNIT_MILLILITRE = "mL"
 UNIT_MILLIMETER = "mm"
 UNIT_MILLISECOND = "ms"
 UNIT_MILLISIEMENS_PER_CENTIMETER = "mS/cm"
@@ -1255,6 +1257,7 @@ UNIT_PARTS_PER_MILLION = "ppm"
 UNIT_PASCAL = "Pa"
 UNIT_PERCENT = "%"
 UNIT_PH = "pH"
+UNIT_POUND = "lb"
 UNIT_PULSES = "pulses"
 UNIT_PULSES_PER_MINUTE = "pulses/min"
 UNIT_REVOLUTIONS_PER_MINUTE = "RPM"

esphome/core/config.py

@@ -589,7 +589,10 @@ async def _add_looping_components() -> None:
 async def to_code(config: ConfigType) -> None:
     cg.add_global(cg.global_ns.namespace("esphome").using)
     # These can be used by user lambdas, put them to default scope
+    # picolibc (IDF 6.0+) declares isnan in global scope, conflicting with using std::isnan
+    cg.add_global(cg.RawStatement("#ifndef __PICOLIBC__"))
     cg.add_global(cg.RawExpression("using std::isnan"))
+    cg.add_global(cg.RawStatement("#endif"))
     cg.add_global(cg.RawExpression("using std::min"))
     cg.add_global(cg.RawExpression("using std::max"))
 

esphome/core/defines.h

@@ -195,6 +195,7 @@
 
 // ESP32-specific feature flags
 #ifdef USE_ESP32
+#define USE_ESP32_CRASH_HANDLER
 #define USE_MQTT_IDF_ENQUEUE
 #define USE_ESPHOME_TASK_LOG_BUFFER
 #define USE_OTA_ROLLBACK
@@ -337,6 +338,7 @@
 #ifdef USE_RP2040
 #define USE_ARDUINO_VERSION_CODE VERSION_CODE(3, 3, 0)
 #define USE_LOOP_PRIORITY
+#define USE_RP2040_CRASH_HANDLER
 #define USE_HTTP_REQUEST_RESPONSE
 #define USE_I2C
 #define USE_LOGGER_USB_CDC

esphome/core/helpers.h

@@ -301,7 +301,7 @@ template<typename T, size_t N> class StaticVector {
 /// Not thread-safe. All access (push/pop/iteration) must occur from a single
 /// context, or the caller must provide external synchronization.
 template<typename T, size_t N> class StaticRingBuffer {
-  using index_type = std::conditional_t<(N <= 255), uint8_t, uint16_t>;
+  using index_type = std::conditional_t<(N <= std::numeric_limits<uint8_t>::max()), uint8_t, uint16_t>;
 
  public:
   class Iterator {
@@ -356,6 +356,13 @@ template<typename T, size_t N> class StaticRingBuffer {
   index_type size() const { return this->count_; }
   bool empty() const { return this->count_ == 0; }
 
+  /// Clear all elements (reset to empty)
+  void clear() {
+    this->head_ = 0;
+    this->tail_ = 0;
+    this->count_ = 0;
+  }
+
   Iterator begin() { return Iterator(this, 0); }
   Iterator end() { return Iterator(this, this->count_); }
   ConstIterator begin() const { return ConstIterator(this, 0); }
@@ -368,6 +375,128 @@ template<typename T, size_t N> class StaticRingBuffer {
   index_type count_{0};
 };
 
+/// Fixed-capacity circular buffer - allocates once at runtime, never reallocates.
+/// Runtime-sized equivalent of StaticRingBuffer - use when capacity is only known at initialization.
+/// Supports FIFO push/pop and iteration over queued elements.
+/// Not thread-safe.
+template<typename T, size_t MAX_CAPACITY = std::numeric_limits<uint16_t>::max()> class FixedRingBuffer {
+  using index_type = std::conditional_t<
+      (MAX_CAPACITY <= std::numeric_limits<uint8_t>::max()), uint8_t,
+      std::conditional_t<(MAX_CAPACITY <= std::numeric_limits<uint16_t>::max()), uint16_t, uint32_t>>;
+
+ public:
+  class Iterator {
+   public:
+    Iterator(FixedRingBuffer *buf, index_type pos) : buf_(buf), pos_(pos) {}
+    T &operator*() { return buf_->data_[(buf_->head_ + pos_) % buf_->capacity_]; }
+    Iterator &operator++() {
+      ++pos_;
+      return *this;
+    }
+    bool operator!=(const Iterator &other) const { return pos_ != other.pos_; }
+
+   private:
+    FixedRingBuffer *buf_;
+    index_type pos_;
+  };
+
+  class ConstIterator {
+   public:
+    ConstIterator(const FixedRingBuffer *buf, index_type pos) : buf_(buf), pos_(pos) {}
+    const T &operator*() const { return buf_->data_[(buf_->head_ + pos_) % buf_->capacity_]; }
+    ConstIterator &operator++() {
+      ++pos_;
+      return *this;
+    }
+    bool operator!=(const ConstIterator &other) const { return pos_ != other.pos_; }
+
+   private:
+    const FixedRingBuffer *buf_;
+    index_type pos_;
+  };
+
+  FixedRingBuffer() = default;
+  ~FixedRingBuffer() {
+    if constexpr (std::is_trivial<T>::value) {
+      ::operator delete(this->data_);
+    } else {
+      delete[] this->data_;
+    }
+  }
+
+  // Disable copy
+  FixedRingBuffer(const FixedRingBuffer &) = delete;
+  FixedRingBuffer &operator=(const FixedRingBuffer &) = delete;
+
+  /// Allocate capacity - can only be called once
+  void init(index_type capacity) {
+    if constexpr (std::is_trivial<T>::value) {
+      // Raw allocation without initialization (elements are written before read)
+      // NOLINTNEXTLINE(bugprone-sizeof-expression)
+      this->data_ = static_cast<T *>(::operator new(capacity * sizeof(T)));
+    } else {
+      this->data_ = new T[capacity];
+    }
+    this->capacity_ = capacity;
+  }
+
+  /// Push a value. Returns false if full.
+  bool push(const T &value) {
+    if (this->count_ >= this->capacity_)
+      return false;
+    this->data_[this->tail_] = value;
+    this->tail_ = (this->tail_ + 1) % this->capacity_;
+    ++this->count_;
+    return true;
+  }
+
+  /// Push a value, overwriting the oldest if full.
+  void push_overwrite(const T &value) {
+    this->data_[this->tail_] = value;
+    this->tail_ = (this->tail_ + 1) % this->capacity_;
+    if (this->count_ >= this->capacity_) {
+      // Buffer full - advance head to drop oldest, count stays at capacity
+      this->head_ = this->tail_;
+    } else {
+      ++this->count_;
+    }
+  }
+
+  /// Remove the oldest element.
+  void pop() {
+    if (this->count_ > 0) {
+      this->head_ = (this->head_ + 1) % this->capacity_;
+      --this->count_;
+    }
+  }
+
+  T &front() { return this->data_[this->head_]; }
+  const T &front() const { return this->data_[this->head_]; }
+  index_type size() const { return this->count_; }
+  bool empty() const { return this->count_ == 0; }
+  index_type capacity() const { return this->capacity_; }
+  bool full() const { return this->count_ == this->capacity_; }
+
+  /// Clear all elements (reset to empty, keep capacity)
+  void clear() {
+    this->head_ = 0;
+    this->tail_ = 0;
+    this->count_ = 0;
+  }
+
+  Iterator begin() { return Iterator(this, 0); }
+  Iterator end() { return Iterator(this, this->count_); }
+  ConstIterator begin() const { return ConstIterator(this, 0); }
+  ConstIterator end() const { return ConstIterator(this, this->count_); }
+
+ protected:
+  T *data_{nullptr};
+  index_type head_{0};
+  index_type tail_{0};
+  index_type count_{0};
+  index_type capacity_{0};
+};
+
 /// Fixed-capacity vector - allocates once at runtime, never reallocates
 /// This avoids std::vector template overhead (_M_realloc_insert, _M_default_append)
 /// when size is known at initialization but not at compile time
@@ -942,6 +1071,28 @@ __attribute__((format(printf, 4, 5))) inline size_t buf_append_printf(char *buf,
 }
 #endif
 
+/// Safely append a string to buffer without format parsing, returning new position (capped at size).
+/// More efficient than buf_append_printf for plain string literals.
+/// @param buf Output buffer
+/// @param size Total buffer size
+/// @param pos Current position in buffer
+/// @param str String to append (must not be null)
+/// @return New position after appending (capped at size on overflow)
+inline size_t buf_append_str(char *buf, size_t size, size_t pos, const char *str) {
+  if (pos >= size) {
+    return size;
+  }
+  size_t remaining = size - pos - 1;  // reserve space for null terminator
+  size_t len = strlen(str);
+  if (len > remaining) {
+    len = remaining;
+  }
+  memcpy(buf + pos, str, len);
+  pos += len;
+  buf[pos] = '\0';
+  return pos;
+}
+
 /// Concatenate a name with a separator and suffix using an efficient stack-based approach.
 /// This avoids multiple heap allocations during string construction.
 /// Maximum name length supported is 120 characters for friendly names.

esphome/core/log.cpp

@@ -86,3 +86,79 @@ int HOT esp_idf_log_vprintf_(const char *format, va_list args) {  // NOLINT
 #endif
 
 }  // namespace esphome
+
+#if defined(USE_ESP32) && !defined(BOOTLOADER_BUILD)
+// Override esp_log_format to prevent V2's 3-call vprintf fragmentation.
+// Without this, Log V2 calls the vprintf hook 3 times per message (header,
+// body, newline) which creates 3 separate log entries in ESPHome's logger.
+// This strong definition overrides the archive symbol from ESP-IDF's liblog,
+// affecting all callers including precompiled blobs (e.g. wifi).
+#include <esp_private/log_message.h>
+#include <esp_log_write.h>
+
+// Format an ESP-IDF log message directly to the console, bypassing the
+// ESPHome logger hook. Used when the hook isn't installed (early boot) or
+// can't be used safely (constrained env: PHY init, efuse reads — fwrite
+// locks crash on USB JTAG devices).
+// Formats in ESPHome style with ANSI colors into a 512-byte stack buffer,
+// then outputs atomically via esp_rom_printf.
+// This path is cold on 99.9% of builds — it only runs during early boot
+// and at DEBUG framework log level (default is ERROR).
+static void __attribute__((noinline)) esp_log_format_direct_(esp_log_msg_t *message) {
+  // ESP-IDF levels: NONE=0 ERROR=1 WARN=2 INFO=3 DEBUG=4 VERBOSE=5
+  // Color digits: E=1(red) W=3(yellow) I=2(green) D=6(cyan) V=7(gray)
+  static const char color_digit[] = {'\0', '1', '3', '2', '6', '7'};
+  static const char lvl[] = {'\0', 'E', 'W', 'I', 'D', 'V'};
+  // Format into stack buffer and output atomically via esp_rom_printf.
+  // Can't use fwrite (locks crash during early boot and PHY init).
+  char buf[512];
+  int pos = 0;
+  uint8_t level = message->config.opts.log_level;
+  if (level > 0 && level < sizeof(lvl)) {
+    pos = snprintf(buf, sizeof(buf), "\033[0;3%cm[%c][%s]: ", color_digit[level], lvl[level],
+                   message->tag ? message->tag : "idf");
+  }
+  if (pos >= 0 && pos < (int) sizeof(buf) - 2) {
+    int body = vsnprintf(buf + pos, sizeof(buf) - pos, message->format, message->args);
+    if (body > 0)
+      pos += (body < (int) sizeof(buf) - pos) ? body : (int) sizeof(buf) - pos - 1;
+  }
+  if (level > 0 && level < sizeof(lvl) && pos < (int) sizeof(buf) - 6) {
+    pos += snprintf(buf + pos, sizeof(buf) - pos, "\033[0m");
+  }
+  if (pos < (int) sizeof(buf) - 1) {
+    buf[pos++] = '\n';
+  }
+  buf[pos] = '\0';
+  esp_rom_printf("%s", buf);
+}
+
+extern "C" {
+// Override esp_log_format from liblog.a to prevent V2's 3-call vprintf
+// fragmentation. IRAM_ATTR to match esp_log_va's IRAM placement and avoid
+// an IRAM→flash cache miss on every ESP-IDF log call. This function is
+// tiny (~43 bytes) so the IRAM cost is negligible.
+void IRAM_ATTR esp_log_format(esp_log_msg_t *message) {
+  extern vprintf_like_t esp_log_vprint_func;
+  extern int vprintf(const char *, __gnuc_va_list);  // NOLINT
+  if (esp_log_vprint_func == &vprintf || message->config.opts.constrained_env) [[unlikely]] {
+    // Early boot or constrained env (PHY init, efuse reads, scheduler not
+    // running). Can't use the ESPHome hook — fwrite locks crash during PHY
+    // init on USB JTAG devices and newlib isn't initialized during early boot.
+    // Format to stack buffer with vsnprintf + esp_rom_printf instead.
+    //
+    // Note: if called from an ISR with flash cache disabled, this will crash
+    // because the format string and tag are in flash. This is the same as V1
+    // where ESP_EARLY_LOGx from ISR also used flash-resident format strings
+    // via esp_rom_printf. No ESP-IDF code is known to log from ISR with
+    // cache disabled.
+    esp_log_format_direct_(message);
+    return;
+  }
+  // After hook installed, normal environment: skip formatting, forward body only.
+  // Call esp_log_vprint_func directly to avoid pulling in esp_rom_vprintf
+  // (1.2KB IRAM) through the esp_log_vprintf inline.
+  esp_log_vprint_func(message->format, message->args);
+}
+}  // extern "C"
+#endif

esphome/core/lwip_fast_select.c

@@ -112,6 +112,7 @@
 // LwIP headers must come first — they define netconn_callback, struct lwip_sock, etc.
 #include <lwip/api.h>
 #include <lwip/priv/sockets_priv.h>
+#include <lwip/tcp.h>
 // FreeRTOS include paths differ: ESP-IDF uses freertos/ prefix, LibreTiny does not
 #ifdef USE_ESP32
 #include <freertos/FreeRTOS.h>
@@ -216,6 +217,21 @@ void esphome_lwip_hook_socket(struct lwip_sock *sock) {
   sock->conn->callback = esphome_socket_event_callback;
 }
 
+bool esphome_lwip_set_nodelay(struct lwip_sock *sock, bool enable) {
+  if (sock == NULL || sock->conn == NULL)
+    return false;
+  if (NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_TCP)
+    return false;
+  if (sock->conn->pcb.tcp == NULL)
+    return false;
+  if (enable) {
+    tcp_nagle_disable(sock->conn->pcb.tcp);
+  } else {
+    tcp_nagle_enable(sock->conn->pcb.tcp);
+  }
+  return true;
+}
+
 // Wake the main loop from another FreeRTOS task. NOT ISR-safe.
 void esphome_lwip_wake_main_loop(void) {
   TaskHandle_t task = s_main_loop_task;

esphome/core/lwip_fast_select.h

@@ -66,6 +66,13 @@ void esphome_lwip_wake_main_loop(void);
 /// @param px_higher_priority_task_woken Set to pdTRUE if a context switch is needed.
 void esphome_lwip_wake_main_loop_from_isr(int *px_higher_priority_task_woken);
 
+/// Set or clear TCP_NODELAY on a socket's tcp_pcb directly.
+/// Must be called with the TCPIP core lock held (LwIPLock in C++).
+/// This bypasses lwip_setsockopt() overhead (socket lookups, switch cascade,
+/// hooks, refcounting) — just a direct pcb->flags bit set/clear.
+/// Returns true if successful, false if sock/conn/pcb is NULL or the socket is not TCP.
+bool esphome_lwip_set_nodelay(struct lwip_sock *sock, bool enable);
+
 /// Wake the main loop task from any context (ISR, thread, or main loop).
 /// ESP32-only: uses xPortInIsrContext() to detect ISR context.
 /// LibreTiny lacks IRAM_ATTR support needed for ISR-safe paths.

esphome/core/scheduler.cpp

@@ -105,10 +105,11 @@ static void validate_static_string(const char *name) {
 // avoid the main thread modifying the list while it is being accessed.
 
 // Calculate random offset for interval timers
-// Extracted from set_timer_common_ to reduce code size - float math + random_float()
-// only needed for intervals, not timeouts
+// Extracted from set_timer_common_ to reduce code size - only needed for intervals, not timeouts
 uint32_t Scheduler::calculate_interval_offset_(uint32_t delay) {
-  return static_cast<uint32_t>(std::min(delay / 2, MAX_INTERVAL_DELAY) * random_float());
+  uint32_t max_offset = std::min(delay / 2, MAX_INTERVAL_DELAY);
+  // Multiply-and-shift: uniform random in [0, max_offset) without floating point
+  return static_cast<uint32_t>((static_cast<uint64_t>(random_uint32()) * max_offset) >> 32);
 }
 
 // Check if a retry was already cancelled in items_ or to_add_