[epaper_spi] Skip the refresh when the frame is unchanged (#20333)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: J. Nick Koston <nick@home-assistant.io>

.agents/skills/hardware-test/SKILL.md

@@ -115,7 +115,7 @@ Per-topic scripts, each described in the matching `reference/recipes/<component>
 (host driver, Zephyr driver probe), `rtsp_server/` (protocol client, raw rate reader, measurement set,
 API image grab), `cse7766/` (API observer with ping), `zephyr_coredump/` (reader flow, decode with the
 Zephyr tools), `libretiny_prefs/` (rtc preference harness header), `libretiny_crash/` (BK72xx crash probe header and
-capture decoder), `api_outgoing/` (wake cycle and Wi-Fi drop timing readers), `ld2450/` (zone number driver), `dfrobot_sen0395/` (API driver and case runner), `homeassistant_light/` (direct bulb driver, held-report case driver), `usb_audio/` (URL player), `speaker_media_player/` (API player driver, pipeline task case runner), `web_server/` (SSE client, request mix, SSE and HTTPD case runners), `mqtt/` (broker config with TLS, client-certificate and WebSocket listeners, test CA with server and client certificates, transport case runner, flash-and-drive runner, CLI TLS check without a board), `udp/` (datagram recorder, `udp.write` payload checker and case driver), `entity_icons/` (icon and device class readback over the API, MQTT discovery, web_server and dump_config, with a comparer).
+capture decoder), `api_outgoing/` (wake cycle and Wi-Fi drop timing readers), `ld2450/` (zone number driver, loopback harness driver with number and binary sensor states and TX frame summarizer), `api/` (raw plaintext native API client for user defined actions), `dfrobot_sen0395/` (API driver and case runner), `homeassistant_light/` (direct bulb driver, held-report case driver), `usb_audio/` (URL player), `speaker_media_player/` (API player driver, pipeline task case runner), `web_server/` (SSE client, request mix, SSE and HTTPD case runners), `mqtt/` (broker config with TLS, client-certificate and WebSocket listeners, test CA with server and client certificates, transport case runner, flash-and-drive runner, CLI TLS check without a board), `udp/` (datagram recorder, `udp.write` payload checker and case driver), `entity_icons/` (icon and device class readback over the API, MQTT discovery, web_server and dump_config, with a comparer).
 
 ## Templates in `$SKILL/templates`
 

.agents/skills/hardware-test/reference/boards.md

@@ -7,6 +7,9 @@ Ports are not listed on purpose: they follow the USB hub port and change on ever
 
 - Opening the port usually resets the board through DTR, but not always; `serial_capture.py --reset`
   pulses RTS to capture from boot. 74880 baud shows the ROM boot messages (`rst cause`, `boot mode`).
+- UART0 can be looped back onto itself (`USC0(0) |= (1 << UCLBE)` in an `on_boot` lambda) so a UART
+  component is testable without its device: frames written with `uart.write` arrive on RX. Log over the
+  API with `logger: baud_rate: 0`, since the serial port carries the component's bytes.
 - `esphome logs` on some CH340s emits thousands of duplicated garbage lines right after the RTS reset;
   a plain pyserial capture at 115200 is reliable.
 - A failed esptool write can wedge the adapter (`termios` error 22, or an open that hangs) until replug.

.agents/skills/hardware-test/reference/recipes/README.md

@@ -4,12 +4,13 @@ Each flow names the pull requests it was used on, so their result tables show wh
 
 One file per component, named after it:
 
-- [`api.md`](api.md): noise handshake and OTA encryption on the ESP8266, outgoing connection wake timing on deep sleep and after a Wi-Fi drop
+- [`api.md`](api.md): noise handshake and OTA encryption on the ESP8266, outgoing connection wake timing on deep sleep and after a Wi-Fi drop, user defined action listing and execution with a raw plaintext client
 - [`captive_portal.md`](captive_portal.md): fallback AP and /wifisave hammer
 - [`cse7766.md`](cse7766.md): Sonoff S31 parser check over the API
 - [`espnow.md`](espnow.md): ESP8266 broadcast receive
 - [`hdmi_cec.md`](hdmi_cec.md): two-board wire
-- [`ld2450.md`](ld2450.md): polygon zones, zone number round trip through the radar's readback
+- [`ld2450.md`](ld2450.md): polygon zones, zone number round trip through the radar's readback, ESP8266 loopback harness without a radar
+- [`ld2412.md`](ld2412.md): output pin level through the basic configuration command, held back writes
 - [`libretiny.md`](libretiny.md): rtc preference emulation, BK72xx crash report on the next boot
 - [`mqtt.md`](mqtt.md): broker bench, QoS, reconnect, crash log over MQTT, WebSocket transports with a local and a public broker, TLS trust sources (own CA, client certificate, certificate bundle, no verification) with the CLI check
 - [`nrf52.md`](nrf52.md): dongle board support
@@ -20,7 +21,7 @@ One file per component, named after it:
 - [`scheduler.md`](scheduler.md): loop wake A/B
 - [`udp.md`](udp.md): datagrams, multicast, sockets, `udp.write` payload shapes
 - [`usb_cdc_acm.md`](usb_cdc_acm.md): nRF52840 dongle host driver
-- [`wifi.md`](wifi.md): reboot_timeout with a fallback AP, DHCP lease cache, Easy Connect (DPP)
+- [`wifi.md`](wifi.md): reboot_timeout with a fallback AP, DHCP lease cache, Easy Connect (DPP), WISP bridge with an ethernet upstream
 - [`zephyr.md`](zephyr.md): preferences on the nRF52840 dongle
 - [`zephyr_coredump.md`](zephyr_coredump.md): crash and decode on nRF52 boards
 - [`zwave_proxy.md`](zwave_proxy.md): frame checksums on a live proxy

.agents/skills/hardware-test/reference/recipes/api.md

@@ -28,3 +28,15 @@ connected first, and the loop-time maxima. For the loop cost of polling, repeat
 so after a drop every dial is closed and HA's incoming reconnect wins 11 to 33 s later; the measurable effect is the
 first dial landing in the loop the network flag flips.
 Results: https://github.com/esphome/esphome/pull/21085#issuecomment-6254742791
+
+## User defined action listing and execution without a client library (#18882)
+
+`scripts/api/rawactions.py HOST list` speaks the plaintext native API over a raw socket and decodes every
+`ListEntitiesServicesResponse` by field number (argument fields 1 name, 2 type, 3 description, 4 example, 5 optional,
+6 default_value), so new wire fields show up without waiting for the client library. `rawactions.py HOST exec ACTION
+k=v ...` sends `ExecuteServiceRequest` with `sint32` ints (field 5, not the legacy int32 field 2), fixed32 floats,
+length delimited strings and `int[]` as repeated sint32 (field 7); `ALLOW_MISSING=1` leaves arguments out on purpose
+(the device then drops the call). `templates/api-actions-dut.yaml` (D1 mini, three actions, optional variables with
+defaults) and `templates/api-actions-strings-dut.yaml` (required strings) log what arrived. String arguments are
+`StringRef`s that are not null terminated: copy them with `snprintf("%.*s", size, c_str())` into a buffer before
+logging, and do not pass `%.*s` to `logger.log`, whose validator counts it as one pattern.

.agents/skills/hardware-test/reference/recipes/ld2412.md

@@ -0,0 +1,13 @@
+# ld2412
+
+## Output pin level and the basic configuration command (#21353)
+
+`templates/ld2412-select-only-dut.yaml` (ESP32-S3, the module on GPIO43 and GPIO44 at 115200, only the output pin
+level select, the module's OUT pin on GPIO38 as a binary sensor plus the presence sensor) with `uart: debug:
+direction: BOTH`. Drive the select with `scripts/ld2450/lddrive.py HOST KEY LOGFILE sel:NAME=OPTION` and read the TX
+dump for command `02` carrying the level byte, then the OUT pin binary sensor against presence: with level high the
+pin follows presence, with level low it is inverted. A module that never answers the boot query (no `<<<` lines)
+only shows the held back path: `Command 02 held back until the module reports its settings`, a query `12`, and after
+2 s `Command 02 not sent, the module did not report its settings` with the select republished to the last known
+level. With the full set of numbers configured a select change also needs every number to have a state, so wait
+for the boot query answer before judging.

.agents/skills/hardware-test/reference/recipes/ld2450.md

@@ -13,3 +13,30 @@ selects over the API and prints every LD2450 state update. After each set the hu
 the radar and republishes all twelve coordinates from the answer, so set each coordinate of each zone to a distinct
 value and check the readbacks; no target is needed. Readbacks can arrive late over Wi-Fi, so match them by content.
 Results: https://github.com/esphome/esphome/pull/21146#issuecomment-6278026922
+
+## ESP8266 loopback harness, no radar needed (#21349)
+
+`templates/ld2450-loopback.yaml` (package; substitutions `name` and `baud`) runs the hub on UART0 (GPIO1 and GPIO3)
+with `logger: baud_rate: 0` and sets the UART0 loopback bit in `on_boot` (`USC0(0) |= (1 << UCLBE)`), so everything
+the hub or a `uart.write` action sends comes back on RX. Template buttons inject periodic frames (all four direction
+strings, targets 2 and 3), query zone acks (zone type 0, 1 and 2 for the select readback) and call the name based
+setters with a valid and a bogus name. `uart: debug: direction: TX` delimited on the command footer dumps every
+command the hub sends. Drive it with `scripts/ld2450/lddrive.py HOST KEY LOGFILE press:NAME sel:NAME=OPTION wait:S`
+(logs over the API at VERBOSE, 2 s between steps because the API log stream drops lines while `send_command_`
+blocks), then `txsum.py LOGFILE` lists the TX frames per step; diff the summaries of the two builds. The hub reads its
+own commands back and logs `Invalid status` for each, which is harmless. The boot readback of the baud rate select
+comes from the UART setting, so a second build at `baud: "9600"` checks the flash table lookup.
+Results: https://github.com/esphome/esphome/pull/21349#issuecomment-6332320026
+
+## Frame splitter collisions (#21357)
+
+The loopback template also carries the zone 1 numbers and seven collision buttons: a periodic frame with the
+command footer inside target 1, zone acks with `55 CC` and with `04 03 02 01` inside the coordinates, a periodic
+frame cut after 12 bytes followed by a zone ack, a frame missing its last byte followed by a complete one, a bogus
+255 byte length then a frame, and garbage then a frame. Judge by the state updates plus the `Handling Periodic` and
+`Handling Ack` lines. Through a real radar the set zone ack is sometimes corrupted by the radar itself (its tail
+replaced by the periodic frame it was sending, for example `04 03 03 03 00 ... 55 CC`), so count readbacks over at
+least 24 selects per build and read the raw bytes with `uart: debug: direction: RX` (`!extend` the package's uart
+id) before blaming the parser; the API log stream drops lines under that dump volume, so some misses stay
+unclassified.
+Results: https://github.com/esphome/esphome/pull/21357#issuecomment-6333244886

.agents/skills/hardware-test/reference/recipes/wifi.md

@@ -23,3 +23,17 @@ Only an Android phone configures: Settings, network details, Add device, Share W
 QR scanner makes the phone an enrollee). Render the URI with the `qrcode` module and open the PNG.
 `esp32: framework: log_level: DEBUG` plus `sdkconfig_options: CONFIG_WPA_DEBUG_PRINT: y` prints the
 supplicant state machine.
+
+## WISP bridge with an ethernet upstream (#7147)
+
+`templates/wisp-ethernet-dut.yaml` (ESP32-S3 with a W5500, `wifi: ap:` with `ap_mode: WISP` and no station) and
+`templates/wisp-client.yaml` (D1 mini joining the bridge, `http_request` to a web server on the wired LAN and to
+`http://example.com/` every 15 s, `time: sntp`). Secrets: `wisp_psk` and `lan_http` (serve a text file on the host
+with `python -m http.server 8787 --bind 0.0.0.0` from a scratch directory). Judge by the client's `GET status 200`
+lines, the web server log showing the device's ethernet address as the source (NAT), the client's DHCP info (DNS1 is
+the LAN resolver) and `SNTP synced`. The device logs `Starting AP` and `DHCP DNS server: <resolver>` on its USB
+console; flashing over the air reboots it for repeat boots. Before the AP address and DHCP server moved ahead of the
+AP start (the fix in that PR), the first AP start failed on every boot with `esp_netif_dhcps_option failed: 20484`
+(DHCP server already started by the AP start event) and `Failed to enable NAT`, and the bridge only came up on the
+retry 90 s later; a client that cannot find the SSID for the first minute on an older build is that. With the fix
+the bridge is up 6 s after boot. Any change to the ESP-IDF AP start should also rerun the captive portal hammer.

.agents/skills/hardware-test/scripts/api/rawactions.py

@@ -0,0 +1,211 @@
+"""Plaintext native API client that lists user actions with their raw argument fields and executes one.
+
+usage: rawactions.py HOST list
+       rawactions.py HOST exec ACTION key=value [...]   (every argument must be given; types from the listing)
+Fields of ListEntitiesServicesArgument: 1 name, 2 type, 3 description, 4 example, 5 optional, 6 default_value.
+"""
+
+import os
+import socket
+import struct
+import sys
+
+HOST = sys.argv[1]
+CMD = sys.argv[2]
+ARGS = sys.argv[3:]
+TYPE_NAMES = {
+    0: "bool",
+    1: "int",
+    2: "float",
+    3: "string",
+    4: "bool[]",
+    5: "int[]",
+    6: "float[]",
+    7: "string[]",
+}
+
+
+def varint(v: int) -> bytes:
+    out = bytearray()
+    while True:
+        b = v & 0x7F
+        v >>= 7
+        if v:
+            out.append(b | 0x80)
+        else:
+            out.append(b)
+            return bytes(out)
+
+
+def svarint(v: int) -> bytes:
+    return varint((v << 1) ^ (v >> 63))
+
+
+def decode_varint(buf: bytes, pos: int) -> tuple[int, int]:
+    value = shift = 0
+    while True:
+        b = buf[pos]
+        pos += 1
+        value |= (b & 0x7F) << shift
+        if not b & 0x80:
+            return value, pos
+        shift += 7
+
+
+def fields(payload: bytes) -> list[tuple[int, int, object]]:
+    out = []
+    pos = 0
+    while pos < len(payload):
+        key, pos = decode_varint(payload, pos)
+        fnum, wt = key >> 3, key & 7
+        if wt == 0:
+            v, pos = decode_varint(payload, pos)
+        elif wt == 2:
+            ln, pos = decode_varint(payload, pos)
+            v = payload[pos : pos + ln]
+            pos += ln
+        elif wt == 5:
+            v = payload[pos : pos + 4]  # fixed32, caller unpacks
+            pos += 4
+        else:
+            raise ValueError(f"wire type {wt}")
+        out.append((fnum, wt, v))
+    return out
+
+
+def frame(mtype: int, payload: bytes) -> bytes:
+    return b"\x00" + varint(len(payload)) + varint(mtype) + payload
+
+
+def field_bytes(fnum: int, data: bytes) -> bytes:
+    return varint((fnum << 3) | 2) + varint(len(data)) + data
+
+
+def field_varint(fnum: int, v: int) -> bytes:
+    return varint((fnum << 3) | 0) + varint(v)
+
+
+def recv_frames(
+    sock: socket.socket, until: set[int], limit: float = 5.0
+) -> list[tuple[int, bytes]]:
+    sock.settimeout(limit)
+    buf = bytearray()
+    frames = []
+    while True:
+        try:
+            chunk = sock.recv(4096)
+        except TimeoutError:
+            return frames
+        if not chunk:
+            return frames
+        buf += chunk
+        while True:
+            if len(buf) < 3:
+                break
+            if buf[0] != 0:
+                raise ValueError("not plaintext")
+            try:
+                ln, p = decode_varint(buf, 1)
+                mt, p = decode_varint(buf, p)
+            except IndexError:
+                break
+            if len(buf) < p + ln:
+                break
+            frames.append((mt, bytes(buf[p : p + ln])))
+            del buf[: p + ln]
+            if mt in until:
+                return frames
+
+
+def main() -> None:
+    sock = socket.create_connection((HOST, 6053), timeout=5)
+    sock.sendall(
+        frame(
+            1, field_bytes(1, b"rawactions") + field_varint(2, 1) + field_varint(3, 10)
+        )
+    )  # HelloRequest
+    recv_frames(sock, {2})
+    sock.sendall(frame(3, b""))  # ConnectRequest, no password
+    recv_frames(sock, {4})
+    sock.sendall(frame(11, b""))  # ListEntitiesRequest
+    frames = recv_frames(sock, {19})
+    services = {}
+    for mt, payload in frames:
+        if mt != 41:
+            continue
+        name = key = None
+        args = []
+        for fnum, _, v in fields(payload):
+            if fnum == 1:
+                name = v.decode()
+            elif fnum == 2:
+                key = struct.unpack("<I", v)[0]
+            elif fnum == 3:
+                a = {
+                    "name": None,
+                    "type": 0,
+                    "description": None,
+                    "example": None,
+                    "optional": None,
+                    "default": None,
+                }
+                for af, _, av in fields(v):
+                    if af == 1:
+                        a["name"] = av.decode()
+                    elif af == 2:
+                        a["type"] = av
+                    elif af == 3:
+                        a["description"] = av.decode()
+                    elif af == 4:
+                        a["example"] = av.decode()
+                    elif af == 5:
+                        a["optional"] = bool(av)
+                    elif af == 6:
+                        a["default"] = av.decode()
+                    else:
+                        a[f"field{af}"] = av
+                args.append(a)
+        services[name] = (key, args)
+    if CMD == "list":
+        for name, (key, args) in services.items():
+            print(f"action {name} key={key}")
+            for a in args:
+                extra = {
+                    k: v
+                    for k, v in a.items()
+                    if k not in ("name", "type") and v is not None
+                }
+                print(f"  {a['name']}: {TYPE_NAMES.get(a['type'], a['type'])} {extra}")
+        return
+    name = ARGS[0]
+    key, args = services[name]
+    payload = varint((1 << 3) | 5) + struct.pack("<I", key)
+    given = dict(kv.split("=", 1) for kv in ARGS[1:])
+    for a in args:
+        if a["name"] not in given:
+            if os.environ.get("ALLOW_MISSING"):
+                continue  # leave the argument out of the request on purpose
+            sys.exit(f"missing {a['name']}")
+        raw = given[a["name"]]
+        t = a["type"]
+        if t == 0:
+            av = field_varint(1, 1 if raw.lower() == "true" else 0)
+        elif t == 1:
+            av = varint((5 << 3) | 0) + svarint(int(raw))  # sint32 int_
+        elif t == 2:
+            av = varint((3 << 3) | 5) + struct.pack("<f", float(raw))
+        elif t == 3:
+            av = field_bytes(4, raw.encode())
+        elif t == 5:
+            av = b"".join(
+                varint((7 << 3) | 0) + svarint(int(x)) for x in raw.split(",") if x
+            )  # repeated sint32 int_array
+        else:
+            sys.exit(f"type {t} not supported here")
+        payload += field_bytes(2, av)
+    sock.sendall(frame(42, payload))  # ExecuteServiceRequest
+    print(f"sent {name} with {given}")
+    sock.close()
+
+
+main()

.agents/skills/hardware-test/scripts/ld2450/lddrive.py

@@ -0,0 +1,123 @@
+"""Drive an LD24xx harness over the API: press buttons, set selects and numbers, print state updates, save the log.
+
+usage: lddrive.py HOST KEY LOGFILE OP [OP ...]   (KEY of - means a plaintext API)
+  OP: list | press:NAME | sel:NAME=OPTION | set:NAME=VALUE | wait:SECONDS
+Steps are 2 s apart: the API log stream drops lines while the hub blocks in send_command_.
+"""
+
+import asyncio
+from pathlib import Path
+import sys
+import time
+
+from aioesphomeapi import (
+    APIClient,
+    BinarySensorState,
+    ButtonInfo,
+    LogLevel,
+    NumberInfo,
+    NumberState,
+    SelectInfo,
+    SelectState,
+    SensorInfo,
+    SensorState,
+    TextSensorInfo,
+    TextSensorState,
+)
+
+HOST, KEY, LOGFILE = sys.argv[1], sys.argv[2], sys.argv[3]
+OPS = sys.argv[4:]
+T0 = time.time()
+STEP_GAP_S = 2.0
+
+
+def stamp() -> str:
+    return f"{time.time() - T0:7.3f}"
+
+
+async def run(c: APIClient, log) -> None:
+    info = await c.device_info()
+    print(
+        f"device {info.name} esphome {info.esphome_version} compiled {info.compilation_time}"
+    )
+    ents, _ = await c.list_entities_services()
+    by_key = {e.key: e for e in ents}
+    buttons = {e.name: e for e in ents if isinstance(e, ButtonInfo)}
+    selects = {e.name: e for e in ents if isinstance(e, SelectInfo)}
+    numbers = {e.name: e for e in ents if isinstance(e, NumberInfo)}
+
+    def on_state(s) -> None:
+        e = by_key.get(s.key)
+        if e is None:
+            return
+        missing = " (missing)" if getattr(s, "missing_state", False) else ""
+        if isinstance(s, TextSensorState):
+            print(f"{stamp()} TXT {e.name} = {s.state!r}{missing}", flush=True)
+        elif isinstance(s, BinarySensorState):
+            print(f"{stamp()} BIN {e.name} = {s.state}{missing}", flush=True)
+        elif isinstance(s, NumberState):
+            print(f"{stamp()} NUM {e.name} = {s.state:.0f}{missing}", flush=True)
+        elif isinstance(s, SelectState):
+            print(f"{stamp()} SEL {e.name} = {s.state!r}{missing}", flush=True)
+        elif (
+            isinstance(s, SensorState)
+            and isinstance(e, SensorInfo)
+            and "Count" in e.name
+        ):
+            print(f"{stamp()} CNT {e.name} = {s.state:.0f}", flush=True)
+
+    def on_log(msg) -> None:
+        log.write(f"{stamp()} {msg.message.decode(errors='replace')}\n")
+
+    c.subscribe_states(on_state)
+    c.subscribe_logs(on_log, log_level=LogLevel.LOG_LEVEL_VERBOSE)
+    await asyncio.sleep(1.5)
+    for op in OPS:
+        if op == "list":
+            for n in sorted(buttons):
+                print("button:", n)
+            for n in sorted(selects):
+                print("select:", n, selects[n].options)
+            for e in ents:
+                if isinstance(e, TextSensorInfo):
+                    print("text_sensor:", e.name)
+            continue
+        kind, _, rest = op.partition(":")
+        if kind == "wait":
+            await asyncio.sleep(float(rest))
+            continue
+        if kind == "press":
+            if rest not in buttons:
+                sys.exit(f"no button named {rest!r}; have {sorted(buttons)}")
+            print(f"{stamp()} >>> press {rest}", flush=True)
+            log.write(f"{stamp()} >>> press {rest}\n")
+            c.button_command(buttons[rest].key)
+        elif kind == "set":
+            name, _, value = rest.partition("=")
+            if name not in numbers:
+                sys.exit(f"no number named {name!r}; have {sorted(numbers)}")
+            print(f"{stamp()} >>> set {name} = {value}", flush=True)
+            log.write(f"{stamp()} >>> set {name} = {value}\n")
+            c.number_command(numbers[name].key, float(value))
+        elif kind == "sel":
+            name, _, value = rest.partition("=")
+            if name not in selects:
+                sys.exit(f"no select named {name!r}; have {sorted(selects)}")
+            print(f"{stamp()} >>> select {name} = {value}", flush=True)
+            log.write(f"{stamp()} >>> select {name} = {value}\n")
+            c.select_command(selects[name].key, value)
+        else:
+            sys.exit(f"unknown op {op!r}")
+        await asyncio.sleep(STEP_GAP_S)
+    await asyncio.sleep(1)
+
+
+async def main() -> None:
+    c = APIClient(HOST, 6053, None, noise_psk=None if KEY == "-" else KEY)
+    await c.connect(login=True)
+    with Path(LOGFILE).open("w", encoding="utf-8") as log:
+        await run(c, log)
+    await c.disconnect()
+
+
+asyncio.run(main())

.agents/skills/hardware-test/scripts/ld2450/txsum.py

@@ -0,0 +1,33 @@
+"""Summarize an lddrive.py log: for each step, the LD2450 TX frames, commands and publishes.
+
+usage: txsum.py LOGFILE   (diff the output of two builds)
+"""
+
+from pathlib import Path
+import re
+import sys
+
+ANSI = re.compile(r"\x1b\[[0-9;]*m")
+out: list[str] = []
+with Path(sys.argv[1]).open(encoding="utf-8", errors="replace") as log:
+    for raw in log:
+        line = ANSI.sub("", raw.rstrip("\n"))
+        m = re.match(r"\s*[\d.]+ (.*)", line)
+        if not m:
+            continue
+        text = m.group(1)
+        if text.startswith(">>>"):
+            out.append(f"\n# {text[4:]}")
+        elif "[uart_debug" in text:
+            out.append(f"  TX {text.split('>>> ')[1]}")
+        elif "[ld2450" in text and (
+            "Sending COMMAND" in text
+            or "zone type" in text.lower()
+            or "Query zone" in text
+        ):
+            out.append(f"  LOG {text.split(']: ', 1)[1]}")
+        elif "[select:" in text and ">>" in text:
+            out.append(f"  SEL {text.split(']: ', 1)[1]}")
+        elif "[text_sensor:098]" in text:
+            out.append(f"  TXT {text.split(']: ', 1)[1]}")
+print("\n".join(out))

.agents/skills/hardware-test/templates/api-actions-dut.yaml

@@ -0,0 +1,65 @@
+esphome:
+  name: ${name}
+
+esp8266:
+  board: d1_mini
+
+wifi:
+  ssid: !secret wifi_ssid
+  password: !secret wifi_password
+  power_save_mode: none
+
+logger:
+  level: DEBUG
+
+api:
+  reboot_timeout: 0s
+  actions:
+    - action: play_buzzer
+      description: Play a song or build one from parts
+      variables:
+        song_str:
+          type: string
+          description: Full RTTTL string
+          example: "scale:d=4,o=5,b=100:c,d,e"
+          required: false
+        notes:
+          type: string
+          required: false
+        octave:
+          type: int
+          default: 5
+        bpm:
+          type: int
+          default: 100
+        tempo:
+          type: float
+          default: 1.5
+        loud:
+          type: bool
+          default: true
+        label:
+          type: string
+          default: ""
+      then:
+        - lambda: |-
+            char s[40], n[40], l[40];
+            snprintf(s, sizeof(s), "%.*s", (int) song_str.size(), song_str.c_str());
+            snprintf(n, sizeof(n), "%.*s", (int) notes.size(), notes.c_str());
+            snprintf(l, sizeof(l), "%.*s", (int) label.size(), label.c_str());
+            ESP_LOGD("main", "play_buzzer song=%s(%d) notes=%s(%d) octave=%d bpm=%d tempo=%.1f loud=%d label=%s(%d)", s,
+                     (int) song_str.size(), n, (int) notes.size(), octave, bpm, tempo, loud, l, (int) label.size());
+    - action: plain_action
+      variables:
+        value: int
+      then:
+        - logger.log:
+            format: "plain_action value=%d"
+            args: ["value"]
+    - action: list_action
+      variables:
+        values: int[]
+      then:
+        - logger.log:
+            format: "list_action n=%d"
+            args: ["values.size()"]

.agents/skills/hardware-test/templates/api-actions-strings-dut.yaml

@@ -0,0 +1,28 @@
+esphome:
+  name: ${name}
+
+esp8266:
+  board: d1_mini
+
+wifi:
+  ssid: !secret wifi_ssid
+  password: !secret wifi_password
+  power_save_mode: none
+
+logger:
+  level: DEBUG
+
+api:
+  reboot_timeout: 0s
+  actions:
+    - action: str_action
+      variables:
+        song_str: string
+        notes: string
+        octave: int
+      then:
+        - lambda: |-
+            char s[40], n[40];
+            snprintf(s, sizeof(s), "%.*s", (int) song_str.size(), song_str.c_str());
+            snprintf(n, sizeof(n), "%.*s", (int) notes.size(), notes.c_str());
+            ESP_LOGD("main", "str_action song=%s(%d) notes=%s(%d) octave=%d", s, (int) song_str.size(), n, (int) notes.size(), octave);

.agents/skills/hardware-test/templates/ld2412-select-only-dut.yaml

@@ -0,0 +1,57 @@
+substitutions:
+  name: ld2412sel
+
+esphome:
+  name: ${name}
+
+esp32:
+  variant: esp32s3
+  board: esp32-s3-devkitc-1
+  flash_size: 8MB
+  framework:
+    type: esp-idf
+
+logger:
+  level: VERBOSE
+
+api:
+  reboot_timeout: 0s
+
+ota:
+  - platform: esphome
+
+wifi:
+  ssid: !secret wifi_ssid
+  password: !secret wifi_password
+  power_save_mode: none
+
+uart:
+  - id: uart_ld2412
+    tx_pin: GPIO43
+    rx_pin: GPIO44
+    baud_rate: 115200
+    debug:
+      direction: BOTH
+      dummy_receiver: false
+      after:
+        timeout: 10ms
+        bytes: 120
+
+ld2412:
+  id: ld2412_radar
+  uart_id: uart_ld2412
+
+select:
+  - platform: ld2412
+    ld2412_id: ld2412_radar
+    out_pin_level:
+      name: "LD2412 Hardware output pin level"
+
+binary_sensor:
+  - platform: gpio
+    name: "LD2412 Out Pin"
+    pin: GPIO38
+  - platform: ld2412
+    ld2412_id: ld2412_radar
+    has_target:
+      name: "LD2412 Presence"

.agents/skills/hardware-test/templates/ld2450-loopback.yaml

@@ -0,0 +1,258 @@
+esphome:
+  name: ${name}
+  on_boot:
+    priority: -100
+    then:
+      - lambda: |-
+          // UART0 TX looped back into its own RX so injected frames reach the hub
+          USC0(0) |= (1 << UCLBE);
+          ESP_LOGI("harness", "UART0 loopback on");
+
+esp8266:
+  board: d1_mini
+
+wifi:
+  ssid: !secret wifi_ssid
+  password: !secret wifi_password
+
+api:
+  reboot_timeout: 0s
+
+logger:
+  baud_rate: 0
+  level: VERBOSE
+
+uart:
+  id: radar_uart
+  tx_pin: GPIO1
+  rx_pin: GPIO3
+  baud_rate: ${baud}
+  debug:
+    direction: TX
+    dummy_receiver: false
+    after:
+      delimiter: [0x04, 0x03, 0x02, 0x01]
+
+ld2450:
+  id: radar
+  uart_id: radar_uart
+
+select:
+  - platform: ld2450
+    baud_rate:
+      name: Baud Rate
+    zone_type:
+      name: Zone Type
+
+text_sensor:
+  - platform: ld2450
+    version:
+      name: Radar Version
+    target_1:
+      direction:
+        name: T1 Direction
+    target_2:
+      direction:
+        name: T2 Direction
+    target_3:
+      direction:
+        name: T3 Direction
+
+sensor:
+  - platform: ld2450
+    target_count:
+      name: Target Count
+
+button:
+  # periodic frames: header, 3 x (x, y, speed, resolution), footer
+  - platform: template
+    name: Frame Approach
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xAA, 0xFF, 0x03, 0x00,
+                 0x00, 0x00, 0xE8, 0x83, 0x14, 0x00, 0x64, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x55, 0xCC]
+  - platform: template
+    name: Frame Away
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xAA, 0xFF, 0x03, 0x00,
+                 0x00, 0x00, 0xE8, 0x83, 0x14, 0x80, 0x64, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x55, 0xCC]
+  - platform: template
+    name: Frame Stationary
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xAA, 0xFF, 0x03, 0x00,
+                 0x00, 0x00, 0xE8, 0x83, 0x00, 0x00, 0x64, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x55, 0xCC]
+  - platform: template
+    name: Frame None
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xAA, 0xFF, 0x03, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x55, 0xCC]
+  - platform: template
+    name: Frame T2 T3
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xAA, 0xFF, 0x03, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0xF4, 0x81, 0x20, 0x83, 0x1E, 0x00, 0x64, 0x00,
+                 0x2C, 0x01, 0xB0, 0x84, 0x0A, 0x80, 0x64, 0x00,
+                 0x55, 0xCC]
+  # query zone acks: header, length, command C1, status 01, 00 00, zone type, 00, 24 coordinate bytes, footer
+  - platform: template
+    name: Zone Ack Disabled
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xFD, 0xFC, 0xFB, 0xFA, 0x1E, 0x00, 0xC1, 0x01, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x04, 0x03, 0x02, 0x01]
+  - platform: template
+    name: Zone Ack Detection
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xFD, 0xFC, 0xFB, 0xFA, 0x1E, 0x00, 0xC1, 0x01, 0x00, 0x00, 0x01, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x04, 0x03, 0x02, 0x01]
+  - platform: template
+    name: Zone Ack Filter
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xFD, 0xFC, 0xFB, 0xFA, 0x1E, 0x00, 0xC1, 0x01, 0x00, 0x00, 0x02, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x04, 0x03, 0x02, 0x01]
+  # name based setters, the path lambdas use
+  - platform: template
+    name: Set Zone Filter By Name
+    on_press:
+      - lambda: id(radar).set_zone_type("Filter");
+  - platform: template
+    name: Set Zone Bogus By Name
+    on_press:
+      - lambda: id(radar).set_zone_type("Bogus");
+  - platform: template
+    name: Set Baud 57600 By Name
+    on_press:
+      - lambda: id(radar).set_baud_rate("57600");
+  - platform: template
+    name: Set Baud Bogus By Name
+    on_press:
+      - lambda: id(radar).set_baud_rate("Bogus");
+  # target 1 at x 772, y 258: bytes 04 03 02 01 are the command footer
+  - platform: template
+    name: Frame CmdFooter In Payload
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xAA, 0xFF, 0x03, 0x00,
+                 0x04, 0x03, 0x02, 0x01, 0x00, 0x00, 0x64, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x55, 0xCC]
+  # zone ack, type Detection, zone 1 x1 = 0xCC55: bytes 55 CC are the periodic footer
+  - platform: template
+    name: Zone Ack DataFooter In Payload
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xFD, 0xFC, 0xFB, 0xFA, 0x1E, 0x00, 0xC1, 0x01, 0x00, 0x00, 0x01, 0x00,
+                 0x55, 0xCC, 0xC8, 0x00, 0xDC, 0x05, 0xB8, 0x0B, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x04, 0x03, 0x02, 0x01]
+  # zone ack, type Filter, zone 1 x1 = 0x0304 and y1 = 0x0102: bytes 04 03 02 01 are the command footer
+  - platform: template
+    name: Zone Ack CmdFooter In Payload
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xFD, 0xFC, 0xFB, 0xFA, 0x1E, 0x00, 0xC1, 0x01, 0x00, 0x00, 0x02, 0x00,
+                 0x04, 0x03, 0x02, 0x01, 0xDC, 0x05, 0xB8, 0x0B, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x04, 0x03, 0x02, 0x01]
+  # a periodic frame cut after 12 bytes, then a complete zone ack (type Disabled, zeros)
+  - platform: template
+    name: Cut Frame Then Zone Ack
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xAA, 0xFF, 0x03, 0x00, 0x00, 0x00, 0xE8, 0x83, 0x14, 0x00, 0x64, 0x00,
+                 0xFD, 0xFC, 0xFB, 0xFA, 0x1E, 0x00, 0xC1, 0x01, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x04, 0x03, 0x02, 0x01]
+  # a periodic frame missing its last byte, then a complete one (target 1 moving away)
+  - platform: template
+    name: Cut Frame Then Frame
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xAA, 0xFF, 0x03, 0x00,
+                 0x00, 0x00, 0xE8, 0x83, 0x14, 0x00, 0x64, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x55,
+                 0xAA, 0xFF, 0x03, 0x00,
+                 0x00, 0x00, 0xE8, 0x83, 0x14, 0x80, 0x64, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x55, 0xCC]
+  # a command header claiming a 255 byte payload, then a complete periodic frame (target 1 stationary)
+  - platform: template
+    name: Bogus Length Then Frame
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0xFD, 0xFC, 0xFB, 0xFA, 0xFF, 0x00,
+                 0xAA, 0xFF, 0x03, 0x00,
+                 0x00, 0x00, 0xE8, 0x83, 0x00, 0x00, 0x64, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x55, 0xCC]
+  # five garbage bytes, then a complete periodic frame (target 1 approaching)
+  - platform: template
+    name: Garbage Then Frame
+    on_press:
+      - uart.write:
+          id: radar_uart
+          data: [0x01, 0x02, 0x03, 0x42, 0x99,
+                 0xAA, 0xFF, 0x03, 0x00,
+                 0x00, 0x00, 0xE8, 0x83, 0x14, 0x00, 0x64, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                 0x55, 0xCC]
+
+number:
+  - platform: ld2450
+    presence_timeout:
+      name: Presence Timeout
+    zone_1:
+      x1:
+        name: Z1 X1
+      y1:
+        name: Z1 Y1
+      x2:
+        name: Z1 X2
+      y2:
+        name: Z1 Y2

.agents/skills/hardware-test/templates/wisp-client.yaml

@@ -0,0 +1,57 @@
+substitutions:
+  name: wispcli
+  ap_ssid: wisp-bridge
+
+esphome:
+  name: ${name}
+
+esp8266:
+  board: d1_mini
+
+logger:
+  level: DEBUG
+
+wifi:
+  ssid: ${ap_ssid}
+  password: !secret wisp_psk
+  power_save_mode: none
+  reboot_timeout: 0s
+
+http_request:
+  esp8266_disable_ssl_support: true
+  timeout: 8s
+
+time:
+  - platform: sntp
+    id: sntp_time
+    on_time_sync:
+      - logger.log:
+          format: "SNTP synced"
+          level: INFO
+
+interval:
+  - interval: 15s
+    then:
+      - http_request.get:
+          url: !secret lan_http
+          capture_response: true
+          on_response:
+            - logger.log:
+                format: "LAN GET status %d body %s"
+                args: ["response->status_code", "body.c_str()"]
+                level: INFO
+          on_error:
+            - logger.log:
+                format: "LAN GET failed"
+                level: WARN
+      - http_request.get:
+          url: http://example.com/
+          on_response:
+            - logger.log:
+                format: "WAN GET status %d"
+                args: ["response->status_code"]
+                level: INFO
+          on_error:
+            - logger.log:
+                format: "WAN GET failed"
+                level: WARN

.agents/skills/hardware-test/templates/wisp-ethernet-dut.yaml

@@ -0,0 +1,40 @@
+substitutions:
+  name: wispeth
+  ap_ssid: wisp-bridge
+
+esphome:
+  name: ${name}
+
+esp32:
+  board: esp32-s3-devkitc-1
+  variant: esp32s3
+  flash_size: 16MB
+  framework:
+    type: esp-idf
+
+logger:
+  hardware_uart: USB_SERIAL_JTAG
+  level: VERBOSE
+
+api:
+  encryption:
+    key: !secret api_key
+  reboot_timeout: 0s
+
+ota:
+  - platform: esphome
+
+ethernet:
+  type: W5500
+  clk_pin: GPIO13
+  mosi_pin: GPIO11
+  miso_pin: GPIO12
+  cs_pin: GPIO14
+  interrupt_pin: GPIO10
+  reset_pin: GPIO9
+
+wifi:
+  ap:
+    ssid: ${ap_ssid}
+    password: !secret wisp_psk
+    ap_mode: WISP

.clang-tidy

@@ -12,6 +12,7 @@ Checks: >-
   -bugprone-multi-level-implicit-pointer-conversion,
   -bugprone-narrowing-conversions,
   -bugprone-tagged-union-member-count,
+  -bugprone-signed-bitwise,
   -bugprone-signed-char-misuse,
   -bugprone-switch-missing-default-case,
   -cert-dcl50-cpp,
@@ -39,6 +40,7 @@ Checks: >-
   -cppcoreguidelines-avoid-const-or-ref-data-members,
   -cppcoreguidelines-avoid-do-while,
   -cppcoreguidelines-avoid-magic-numbers,
+  -cppcoreguidelines-explicit-constructor,
   -cppcoreguidelines-init-variables,
   -cppcoreguidelines-macro-to-enum,
   -cppcoreguidelines-macro-usage,
@@ -84,6 +86,7 @@ Checks: >-
   -llvm-use-ranges,
   -llvmlibc-*,
   -misc-const-correctness,
+  -misc-explicit-constructor,
   -misc-include-cleaner,
   -misc-multiple-inheritance,
   -misc-no-recursion,
@@ -113,6 +116,7 @@ Checks: >-
   -objc-*,
   -performance-enum-size,
   -portability-avoid-pragma-once,
+  -portability-no-assembler,
   -portability-template-virtual-member-function,
   -readability-ambiguous-smartptr-reset-call,
   -readability-avoid-nested-conditional-operator,
@@ -129,9 +133,13 @@ Checks: >-
   -readability-named-parameter,
   -readability-redundant-casting,
   -readability-redundant-inline-specifier,
+  -readability-redundant-lambda-parameter-list,
   -readability-redundant-member-init,
+  -readability-redundant-nested-if,
   -readability-redundant-parentheses,
   -readability-redundant-typename,
+  -readability-trailing-comma,
+  -readability-trivial-switch,
   -readability-uppercase-literal-suffix,
   -readability-use-anyofallof,
   -readability-use-std-min-max,

.github/workflows/ci.yml

@@ -286,7 +286,7 @@ jobs:
           fi
           echo "version=$version" >> "$GITHUB_OUTPUT"
       - name: Run prek
-        uses: j178/prek-action@1382ad72dea72f9d53832f2bcb65b3e87a947204 # v3.0.1
+        uses: j178/prek-action@af4d4fcb6922b8e6f65c0426947125fcc38794ce # v3.0.2
         with:
           prek-version: ${{ steps.prek.outputs.version }}
           # This job only runs on pull requests, so nothing ever populates

.pre-commit-config.yaml

@@ -38,7 +38,7 @@ repos:
       - id: yamllint
         exclude: ^(\.clang-format|\.clang-tidy)$
   - repo: https://github.com/pre-commit/mirrors-clang-format
-    rev: v22.1.8
+    rev: v23.1.3
     hooks:
       - id: clang-format
         types_or: [c, c++]

AGENTS.md

@@ -205,15 +205,16 @@ file does, and it is the authority when they disagree. The most useful starting
         for a table of structs copy the whole entry out and return the copy, never a pointer into flash.
         On other platforms they are a plain `memcpy` and dereference, so no `#ifdef` is needed. Declare log tags with
         `ESPHOME_LOG_TAG(TAG, "name")`, pass status text as `LOG_STR`, e.g.
-        `this->mark_failed(LOG_STR(ESP_LOG_MSG_COMM_FAIL))`, and give an action whose payload is a byte array
-        a `TEMPLATABLE_BYTES` field so a static code stays in flash.
+        `this->mark_failed(LOG_STR(ESP_LOG_MSG_COMM_FAIL))`. An action that only forwards a byte payload is
+        registered with `automation.ApplyBytes` (see Actions below), which keeps a constant payload in flash;
+        `TEMPLATABLE_BYTES` is for a `play()` that does more with the bytes.
     *   **Fixed sets of names** (status words, model names): a `PROGMEM_STRING_TABLE` (`esphome/core/progmem.h`),
         logged with `get_log_str` and `LOG_STR_ARG`, copied out with `ESPHOME_strncpy_P` before `publish_state`.
         A `dump_config` helper that picks a name returns `const LogString *` from `LOG_STR(...)`.
     *   **CRCs and bit tricks** come from `esphome/core/helpers.h` (`crc8`, `crc16`, `xor_bytes`, `sum16_bytes`,
-        `reverse_bits`, `encode_uint16`, `encode_value_le`, `sign_extend<BITS>`, `bcd_to_uint8`); pick the helper's
-        arguments instead of writing a loop. Epson style 7-byte RTC calendars (one-hot weekday) use
-        `time::decode_bcd_calendar`.
+        `reverse_bits`, `encode_uint16`, `encode_value_le`, `sign_extend<BITS>`, `bcd_to_uint8`, `assign_bits`); pick
+        the helper's arguments instead of writing a loop. 7-byte BCD RTC calendars use `time::decode_bcd_calendar<LAYOUT>`
+        and `encode_bcd_calendar<LAYOUT>` with `EPSON_BCD_CALENDAR`, `DS_BCD_CALENDAR` or `PCF_BCD_CALENDAR`.
     *   **Bus helpers:** UART drains with `read_available(on_byte)` and `discard_available()`, text lines with
         `LineReader<N>`; I2C has `update_register`, `write_registers` (PROGMEM `I2CRegValue` table), `check_chip_id`
         and `read_bytes_16_le`. `if (!this->status_comm_result(ok)) return;` sets or clears the warning.
@@ -445,6 +446,8 @@ file does, and it is the authority when they disagree. The most useful starting
           switches = switch.sub_switches(config, parent=hub)
           await switches(CONF_BLUETOOTH, None, apply="set_bluetooth(state)", publish="after")
           ```
+          Restore an owned or standalone switch in `setup()` with `sw->restore()`, or `restore(default)`
+          to still drive a state when the restore mode is disabled.
 
         - **Other codegen helpers:** `uart.new_uart_component(config, *ctor_args)` (and `i2c.new_i2c_component`,
           `spi.new_spi_component`, `modbus.new_modbus_client_component`, `ble_client.new_ble_node_component`)
@@ -604,7 +607,9 @@ file does, and it is the authority when they disagree. The most useful starting
         )
         ```
         The `ApplyField`, `ApplyCall` and `register_apply_action` docstrings in `esphome/automation.py` cover
-        the rest; `cover.control` and `cover.template.publish` are in-tree examples. `TEMPLATABLE_VALUE` with
+        the rest; `cover.control` and `cover.template.publish` are in-tree examples. An action whose input is a
+        byte payload passes `automation.ApplyBytes(CONF_DATA, "send({})")` in the same call; a constant payload
+        stays in flash and a lambda's vector is forwarded as data and size. `TEMPLATABLE_VALUE` with
         `cg.templatable` stays for actions whose `play()` has real logic beyond forwarding values.
 
     *   **Conditions:**

CODEOWNERS

@@ -147,6 +147,7 @@ esphome/components/cst816/* @clydebarrow
 esphome/components/cst9220/* @clydebarrow
 esphome/components/ct_clamp/* @jesserockz
 esphome/components/current_based/* @djwmarcx
+esphome/components/cw2017/* @exciton
 esphome/components/d01/* @ch604
 esphome/components/dac7678/* @NickB1
 esphome/components/daikin_arc/* @MagicBear
@@ -174,6 +175,11 @@ esphome/components/ds2484/* @mrk-its
 esphome/components/ds248x/* @tomwellnitz
 esphome/components/ds3231/* @linkedupbits
 esphome/components/dsmr/* @glmnet @PolarGoose
+esphome/components/duco/* @kokx
+esphome/components/duco/number/* @kokx
+esphome/components/duco/select/* @kokx
+esphome/components/duco/sensor/* @kokx
+esphome/components/duco/text_sensor/* @kokx
 esphome/components/duty_time/* @dudanov
 esphome/components/ecocomfort2/* @gledian
 esphome/components/ee895/* @Stock-M
@@ -325,6 +331,7 @@ esphome/components/internal_temperature/* @Mat931
 esphome/components/interval/* @esphome/core
 esphome/components/ir_rf_base/* @bdraco @kbx81
 esphome/components/ir_rf_proxy/* @kbx81
+esphome/components/islandaire/* @ipopov
 esphome/components/it8951/* @koosoli @limengdu @Passific
 esphome/components/jsn_sr04t/* @Mafus1
 esphome/components/json/* @esphome/core
@@ -356,6 +363,7 @@ esphome/components/lm75b/* @beormund
 esphome/components/ln882h_ble/* @Bl00d-B0b
 esphome/components/ln882h_ble_tracker/* @Bl00d-B0b
 esphome/components/ln882x/* @lamauny
+esphome/components/ln882x_spi_led_strip/* @sebo-b
 esphome/components/lock/* @esphome/core
 esphome/components/logger/* @esphome/core
 esphome/components/logger/select/* @clydebarrow
@@ -366,11 +374,13 @@ esphome/components/ltr390/* @latonita @sjtrny
 esphome/components/ltr501/* @latonita
 esphome/components/ltr_als_ps/* @latonita
 esphome/components/lvgl/* @clydebarrow
+esphome/components/m5stack_4relay/* @KoenBreeman
 esphome/components/m5stack_8angle/* @rnauber
 esphome/components/mapping/* @clydebarrow
 esphome/components/matrix_keypad/* @ssieb
 esphome/components/max17043/* @blacknell
-esphome/components/max17048/* @B48D81EFCC
+esphome/components/max17048/* @B48D81EFCC @ryansch
+esphome/components/max170xx/* @ryansch
 esphome/components/max31865/* @DAVe3283
 esphome/components/max31888/* @JiriPrchal
 esphome/components/max44009/* @berfenger
@@ -458,6 +468,8 @@ esphome/components/openthread/* @mrene
 esphome/components/opt3001/* @ccutrer
 esphome/components/ota/* @esphome/core
 esphome/components/output/* @esphome/core
+esphome/components/packet_interface/* @clydebarrow
+esphome/components/packet_interface/packet_transport/* @clydebarrow
 esphome/components/packet_transport/* @clydebarrow
 esphome/components/pca6416a/* @Mat931
 esphome/components/pca9505/* @ajfriesen @ssieb
@@ -537,6 +549,7 @@ esphome/components/sdp3x/* @Azimath
 esphome/components/seeed_mr24hpc1/* @limengdu
 esphome/components/seeed_mr60bha2/* @limengdu
 esphome/components/seeed_mr60fda2/* @limengdu
+esphome/components/seeed_multi_channel_relay/* @KoenBreeman
 esphome/components/selec_meter/* @sourabhjaiswal
 esphome/components/select/* @esphome/core
 esphome/components/sen0321/* @notjj
@@ -677,6 +690,7 @@ esphome/components/tuya/water_heater/* @iago-veiga
 esphome/components/uart/* @esphome/core
 esphome/components/uart/button/* @ssieb
 esphome/components/uart/event/* @eoasmxd
+esphome/components/uart/packet_interface/* @clydebarrow
 esphome/components/uart/packet_transport/* @clydebarrow
 esphome/components/uart_mux/* @kbx81
 esphome/components/uart_tcp/* @Bascht74
@@ -700,6 +714,7 @@ esphome/components/veml7700/* @latonita
 esphome/components/version/* @esphome/core
 esphome/components/vevor_dtx/* @Bofr5555
 esphome/components/vl53l1x/* @will-tm
+esphome/components/vnc/* @MindFreeze
 esphome/components/voice_assistant/* @jesserockz @kahrendt
 esphome/components/wake_on_lan/* @clydebarrow @willwill2will54
 esphome/components/watchdog/* @oarcher

esphome/automation.py

@@ -24,6 +24,7 @@ from esphome.const import (
 )
 from esphome.core import CORE, ID, EsphomeError, HexInt, Lambda
 from esphome.cpp_generator import (
+    CallExpression,
     Expression,
     LambdaExpression,
     MockObj,
@@ -59,10 +60,15 @@ async def templatable_bytes(
     if cg.is_template(value):
         fn = await cg.templatable(value, args, cg.std_vector.template(cg.uint8))
         cg.add(set_template(fn))
-    elif len(value) > 0xFFFF:
-        raise EsphomeError(f"Byte payload is {len(value)} bytes; the maximum is 65535")
     else:
-        cg.add(set_static(progmem_bytes(table_name, value), len(value)))
+        cg.add(set_static(*_static_bytes(table_name, value)))
+
+
+def _static_bytes(table_name: str, value: bytes | list[int]) -> tuple[MockObj, int]:
+    """The shared PROGMEM table for a constant payload and its length."""
+    if (size := len(value)) > 0xFFFF:
+        raise EsphomeError(f"Byte payload is {size} bytes; the maximum is 65535")
+    return progmem_bytes(table_name, value), size
 
 
 def maybe_simple_id(*validators):
@@ -356,6 +362,33 @@ class ApplyField:
         return ApplyCall(target, ((self.conf_key, self.type_, self.const_fn),))
 
 
+@dataclass(frozen=True)
+class ApplyBytes:
+    """A byte payload key forwarded as ``target``, whose ``{}`` stands for ``data, len``.
+
+    A constant payload is a shared PROGMEM table passed as is; on ESP8266 it is first copied
+    out, to the stack up to ``stack`` bytes and to the heap beyond, unless ``progmem_target``
+    names a call that reads flash itself. A lambda's ``std::vector<uint8_t>`` is passed as
+    its data and size. The template may name the parent as ``{parent}``. An absent key
+    emits nothing.
+    """
+
+    conf_key: str | tuple[str, ...]
+    target: str
+    stack: int = 64
+    progmem_target: str | None = None
+
+    def __post_init__(self) -> None:
+        for target in (self.target, self.progmem_target):
+            if target is None:
+                continue
+            fields = [
+                f for _, f, _, _ in string.Formatter().parse(target) if f is not None
+            ]
+            if fields.count("") != 1 or any(f not in ("", "parent") for f in fields):
+                raise ValueError(f"apply bytes target {target!r} needs one {{}}")
+
+
 def _config_lookup(config: ConfigType, key: str | tuple[str, ...]) -> Any:
     if isinstance(key, str):
         return config.get(key)
@@ -414,9 +447,17 @@ async def _apply_parent(config: ConfigType, id_key: str = CONF_ID) -> str:
 
 
 def _apply_lambda_args(args: TemplateArgsType) -> TemplateArgsType:
-    # The generated function's parameters; a std::string arg is never copied.
+    # The generated function's parameters: a reference keeps its spelling, so a mutable
+    # one stays mutable; a value is taken by const reference, so a std::string is never copied.
     return [
-        (cg.RawExpression(f"const std::remove_cvref_t<{cg.safe_exp(t)}> &"), arg)
+        (
+            (
+                t
+                if str(cg.safe_exp(t)).rstrip().endswith("&")
+                else cg.RawExpression(f"const std::remove_cvref_t<{cg.safe_exp(t)}> &")
+            ),
+            arg,
+        )
         for t, arg in args
     ]
 
@@ -488,7 +529,7 @@ def _apply_values(config: ConfigType, members: list[tuple[Any, Any, Any]]) -> li
 def register_apply_action(
     name: str,
     schema: cv.Schema,
-    *fields: ApplyField | ApplyCall,
+    *fields: ApplyField | ApplyCall | ApplyBytes,
     call: str | None = None,
     id_key: str = CONF_ID,
 ) -> None:
@@ -504,7 +545,7 @@ def register_apply_action(
 def apply_action_builder(
     name: str,
     schema: cv.Schema,
-    *fields: ApplyField | ApplyCall,
+    *fields: ApplyField | ApplyCall | ApplyBytes,
     call: str | None = None,
     id_key: str = CONF_ID,
 ) -> Callable[..., Awaitable[MockObj]]:
@@ -517,17 +558,20 @@ def apply_action_builder(
     and ``apply_call.perform()`` is appended.
     """
     # An action stores the value, so a std::string constant stays in flash on ESP8266.
-    statements_spec = [
-        (
-            c.target,
-            _default_std_string(c.members, flash_string),
-        )
-        for c in (f if isinstance(f, ApplyCall) else f.call() for f in fields)
-    ]
     _check_key_in_schema(name, schema, id_key)
-    for _, members in statements_spec:
+    statements_spec: list[ApplyBytes | tuple[str, list[tuple[Any, Any, Any]]]] = []
+    for f in fields:
+        if isinstance(f, ApplyBytes):
+            _check_key_in_schema(name, schema, f.conf_key)
+            statements_spec.append(f)
+            continue
+        c = f if isinstance(f, ApplyCall) else f.call()
+        members = _default_std_string(c.members, flash_string)
         for conf_key, _, _ in members:
             _check_key_in_schema(name, schema, conf_key)
+        statements_spec.append((c.target, members))
+    # Named like the generated function, so it cannot clash with an SDK symbol
+    table_name = f"esphome__{name.replace('.', '_')}__bytes"
 
     async def builder(
         config: ConfigType,
@@ -539,7 +583,15 @@ def apply_action_builder(
         lambda_args = _apply_lambda_args(args)
         receiver = "apply_call." if call else f"{parent}->"
         statements: list[str] = []
-        for target, members in statements_spec:
+        for spec in statements_spec:
+            if isinstance(spec, ApplyBytes):
+                statements.extend(
+                    await _render_bytes(
+                        spec, config, receiver, parent, args, table_name
+                    )
+                )
+                continue
+            target, members = spec
             values = _apply_values(config, members)
             if not _apply_call_active(members, values):
                 continue
@@ -560,6 +612,62 @@ def apply_action_builder(
     return builder
 
 
+async def _render_bytes(
+    spec: ApplyBytes,
+    config: ConfigType,
+    receiver: str,
+    parent: str,
+    args: TemplateArgsType,
+    table_name: str,
+) -> list[str]:
+    """The statements for one ``ApplyBytes``: what ``TemplatableBytes::visit`` does, inlined.
+
+    The payload lambda keeps the automation's own argument types, as ``TemplatableBytes``
+    gave it, and is always called, so a body that modifies an argument still compiles.
+    """
+    value = _config_lookup(config, spec.conf_key)
+    if value is None:
+        return []
+
+    # The temporary carries the generated-name prefix so a trigger argument cannot shadow it
+    def send(target: str, data: str) -> str:
+        return f"{receiver}{target.format(data, parent=parent)};"
+
+    if isinstance(value, Lambda):
+        inner = await cg.process_lambda(
+            value, args, return_type=cg.std_vector.template(cg.uint8)
+        )
+        # Never reduced into the outer function, whose own parameters are const
+        call = CallExpression(inner, *[cg.MockObj(name) for _, name in args])
+        return [
+            "{",
+            f"  const std::vector<uint8_t> esphome__bytes = {call};",
+            f"  {send(spec.target, 'esphome__bytes.data(), esphome__bytes.size()')}",
+            "}",
+        ]
+    table, size = _static_bytes(table_name, value)
+    # Qualified so a trigger argument cannot shadow a reused table; an empty payload is nullptr
+    table_args = f"::{table}, {size}" if size else f"{table}, {size}"
+    if CORE.is_esp8266 and spec.progmem_target is not None:
+        return [send(spec.progmem_target, table_args)]
+    if not CORE.is_esp8266:
+        return [send(spec.target, table_args)]
+    # A PROGMEM table must be read with aligned loads on ESP8266, so copy it out first;
+    # the length is known here, so the copy is an exact array, on the heap past ``stack``.
+    # An empty payload still gets a one byte array: the raw lwIP socket rejects a null buffer.
+    if size <= spec.stack:
+        buffer, data = f"uint8_t esphome__bytes[{max(size, 1)}];", "esphome__bytes"
+    else:
+        buffer, data = (
+            f"auto esphome__bytes = std::make_unique<uint8_t[]>({size});",
+            "esphome__bytes.get()",
+        )
+    statements = ["{", f"  {buffer}"]
+    if size:
+        statements.append(f"  esphome::progmem_memcpy({data}, {table_args});")
+    return [*statements, f"  {send(spec.target, f'{data}, {size}')}", "}"]
+
+
 def _apply_call_active(members: list[tuple[Any, Any, Any]], values: list[Any]) -> bool:
     """An ``ApplyCall`` is emitted unless it has keys and none of them is set."""
     return not members or any(value is not None for value in values)

esphome/build_helpers/tool_runner.py

@@ -111,7 +111,9 @@ class ToolOutput(RedirectText):
 
     def _emit_line(self, line: str) -> None:
         if self._progress and _PROGRESS.match(line):
-            if not self._is_filtered(line):
+            if self._is_filtered(line):
+                self._drop_line(line)
+            else:
                 text = _fit_terminal(line.strip("\r\n"))
                 self._write_color_replace(f"\r{text}\x1b[K")
                 self._on_progress_line = True

esphome/components/api/__init__.py

@@ -1,5 +1,7 @@
+from collections.abc import Callable
 from ipaddress import IPv4Address, IPv6Address
 import logging
+import math
 import re
 from typing import Any
 
@@ -27,6 +29,7 @@ from esphome.const import (
     CONF_CAPTURE_RESPONSE,
     CONF_DATA,
     CONF_DATA_TEMPLATE,
+    CONF_DEFAULT,
     CONF_DELAY,
     CONF_ENCRYPTION,
     CONF_EVENT,
@@ -136,6 +139,7 @@ SERVICE_ARG_FALLBACK_TYPES: dict[str, MockObj] = {
 CONF_BATCH_DELAY = "batch_delay"
 CONF_CUSTOM_SERVICES = "custom_services"
 CONF_EXAMPLE = "example"
+CONF_REQUIRED = "required"
 CONF_HOMEASSISTANT_SERVICES = "homeassistant_services"
 CONF_HOMEASSISTANT_STATES = "homeassistant_states"
 CONF_LISTEN_BACKLOG = "listen_backlog"
@@ -247,12 +251,66 @@ def _validate_supports_response(value: Any) -> str:
     return cv.enum(SUPPORTS_RESPONSE_OPTIONS, lower=True)(value)
 
 
-VARIABLE_SCHEMA = cv.Schema(
-    {
-        cv.Required(CONF_TYPE): cv.one_of(*SERVICE_ARG_NATIVE_TYPES, lower=True),
-        cv.Optional(CONF_DESCRIPTION): cv.string_strict,
-        cv.Optional(CONF_EXAMPLE): cv.string_strict,
-    }
+def _not_boolean(value: Any) -> Any:
+    # bool is an int subclass, and "true" cannot be parsed as a number by the client
+    if isinstance(value, bool):
+        raise cv.Invalid("Expected a number, got a boolean")
+    return value
+
+
+def _finite(value: float) -> float:
+    if not math.isfinite(value):
+        raise cv.Invalid("Expected a finite number")
+    return value
+
+
+def _no_nul(value: str) -> str:
+    # The default is a C string in flash, so a NUL would cut it short
+    if "\0" in value:
+        raise cv.Invalid("A default cannot contain a NUL character")
+    return value
+
+
+# The wire carries the default as text; the client parses it into ExecuteServiceArgument's
+# types, so the values are kept within what int32 and float hold
+FLOAT32_MAX = 3.4028235e38
+_DEFAULT_VALUE_VALIDATORS: dict[str, Callable[[Any], Any]] = {
+    "bool": cv.boolean,
+    "int": cv.All(_not_boolean, cv.int_range(min=-(2**31), max=2**31 - 1)),
+    "float": cv.All(
+        _not_boolean,
+        cv.float_,
+        _finite,
+        cv.float_range(min=-FLOAT32_MAX, max=FLOAT32_MAX),
+    ),
+    "string": cv.All(cv.string_strict, _no_nul),
+}
+assert _DEFAULT_VALUE_VALIDATORS.keys() == _SERVICE_ARG_SCALAR_TYPES.keys()
+
+
+def _validate_variable_optionality(value: ConfigType) -> ConfigType:
+    """Cross-validate required/default against the variable type."""
+    var_type = value[CONF_TYPE]
+    if _is_optional_var(value) and var_type not in _DEFAULT_VALUE_VALIDATORS:
+        raise cv.Invalid("Array variables cannot be optional")
+    if CONF_DEFAULT in value:
+        if value.get(CONF_REQUIRED) is True:
+            raise cv.Invalid("A variable with a default cannot set required: true")
+        value[CONF_DEFAULT] = _DEFAULT_VALUE_VALIDATORS[var_type](value[CONF_DEFAULT])
+    return value
+
+
+VARIABLE_SCHEMA = cv.All(
+    cv.Schema(
+        {
+            cv.Required(CONF_TYPE): cv.one_of(*SERVICE_ARG_NATIVE_TYPES, lower=True),
+            cv.Optional(CONF_DESCRIPTION): cv.string_strict,
+            cv.Optional(CONF_EXAMPLE): cv.string_strict,
+            cv.Optional(CONF_REQUIRED): cv.boolean,
+            cv.Optional(CONF_DEFAULT): cv.valid,
+        }
+    ),
+    _validate_variable_optionality,
 )
 
 # Accepts the plain `name: type` shorthand or the full mapping form
@@ -464,7 +522,28 @@ def _has_action_metadata(actions: list[ConfigType]) -> bool:
     )
 
 
-def _action_strings(conf: ConfigType, has_metadata: bool) -> list[str | None]:
+def _is_optional_var(var_: ConfigType) -> bool:
+    return CONF_DEFAULT in var_ or var_.get(CONF_REQUIRED) is False
+
+
+def _has_optional_args(actions: list[ConfigType]) -> bool:
+    return any(
+        _is_optional_var(var_)
+        for conf in actions
+        for var_ in conf[CONF_VARIABLES].values()
+    )
+
+
+def _default_to_wire(value: Any) -> str:
+    """Serialize a validated default for the wire; clients coerce by arg type."""
+    if isinstance(value, bool):
+        return "true" if value else "false"
+    return str(value)
+
+
+def _action_strings(
+    conf: ConfigType, has_metadata: bool, has_optional: bool
+) -> list[str | None]:
     """Strings of one action in the table order UserServiceStatic (user_services.h) expects."""
     # An empty description or example is treated as unset
     strings: list[str | None] = [conf[CONF_ACTION]]
@@ -477,6 +556,15 @@ def _action_strings(conf: ConfigType, has_metadata: bool) -> list[str | None]:
                 var_.get(CONF_DESCRIPTION) or None,
                 var_.get(CONF_EXAMPLE) or None,
             ]
+        if has_optional:
+            # The default slot doubles as the optional flag: nullptr for a required variable,
+            # "" for an optional one without a default (an empty string default is the same)
+            if not _is_optional_var(var_):
+                strings.append(None)
+            elif (default := var_.get(CONF_DEFAULT)) is None:
+                strings.append("")
+            else:
+                strings.append(_default_to_wire(default))
     return strings
 
 
@@ -485,9 +573,7 @@ def _validate_wizard(config: ConfigType) -> ConfigType:
     return config
 
 
-FINAL_VALIDATE_SCHEMA = cv.All(
-    _validate_wizard,
-)
+FINAL_VALIDATE_SCHEMA = _validate_wizard
 
 
 def _add_action_strings(index: int, strings: list[str | None]) -> MockObj:
@@ -546,6 +632,9 @@ async def to_code(config: ConfigType) -> None:
         has_metadata = _has_action_metadata(actions)
         if has_metadata:
             cg.add_define("USE_API_USER_DEFINED_ACTION_METADATA")
+        has_optional = _has_optional_args(actions)
+        if has_optional:
+            cg.add_define("USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS")
         # Collect all triggers first, then register all at once with initializer_list
         triggers: list[cg.MockObj] = []
         for index, conf in enumerate(actions):
@@ -589,7 +678,7 @@ async def to_code(config: ConfigType) -> None:
                     native = SERVICE_ARG_NATIVE_TYPES[var_type]
                 service_template_args.append(native)
                 func_args.append((native, name))
-            strings = _action_strings(conf, has_metadata)
+            strings = _action_strings(conf, has_metadata, has_optional)
             table = _add_action_strings(index, strings)
             # Template args: supports_response mode, then user service arg types
             templ = cg.TemplateArguments(supports_response, *service_template_args)

esphome/components/api/api.proto

@@ -608,6 +608,7 @@ message ListEntitiesCoverResponse {
   bool supports_stop = 12;
   uint32 device_id = 13 [(field_ifdef) = "USE_DEVICES"];
   bool supports_stop_tilt = 14;
+  bool supports_toggle = 15;
 }
 
 // Deprecated in API version 1.1
@@ -670,6 +671,7 @@ message CoverCommandRequest {
   bool stop = 8;
   uint32 device_id = 9 [(field_ifdef) = "USE_DEVICES"];
   bool stop_tilt = 10;
+  bool toggle = 11;
 }
 
 // ==================== FAN ====================
@@ -1172,6 +1174,10 @@ message ListEntitiesServicesArgument {
   ServiceArgType type = 2;
   string description = 3 [(field_ifdef) = "USE_API_USER_DEFINED_ACTION_METADATA", (progmem) = true];
   string example = 4 [(field_ifdef) = "USE_API_USER_DEFINED_ACTION_METADATA", (progmem) = true];
+  // Advisory: ExecuteServiceRequest still requires every argument
+  bool optional = 5 [(field_ifdef) = "USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS"];
+  // Always text: bool "true"/"false", numbers parseable as int/float; empty means no default
+  string default_value = 6 [(field_ifdef) = "USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS", (progmem) = true];
 }
 message ListEntitiesServicesResponse {
   option (id) = 41;
@@ -1783,6 +1789,8 @@ message MediaPlayerSupportedFormat {
   uint32 num_channels = 3;
   MediaPlayerFormatPurpose purpose = 4;
   uint32 sample_bytes = 5;
+  // Constant bitrate in kbps for lossy formats; 0 means no preference
+  uint32 bitrate = 6;
 }
 message ListEntitiesMediaPlayerResponse {
   option (id) = 63;

esphome/components/api/api_connection.cpp

@@ -555,6 +555,7 @@ uint16_t APIConnection::try_send_cover_info(EntityBase *entity, APIConnection *c
   msg.supports_tilt = traits.get_supports_tilt();
   msg.supports_stop = traits.get_supports_stop();
   msg.supports_stop_tilt = traits.get_supports_stop_tilt();
+  msg.supports_toggle = traits.get_supports_toggle();
   return fill_and_encode_entity_info_with_device_class(cover, msg, msg.device_class, conn, remaining_size);
 }
 void APIConnection::on_cover_command_request(const CoverCommandRequest &msg) {
@@ -567,6 +568,8 @@ void APIConnection::on_cover_command_request(const CoverCommandRequest &msg) {
     call.set_command_stop();
   if (msg.stop_tilt)
     call.set_command_stop_tilt();
+  if (msg.toggle)
+    call.set_command_toggle();
   call.perform();
 }
 #endif
@@ -1128,6 +1131,7 @@ uint16_t APIConnection::try_send_media_player_info(EntityBase *entity, APIConnec
     media_format.num_channels = supported_format.num_channels;
     media_format.purpose = static_cast<enums::MediaPlayerFormatPurpose>(supported_format.purpose);
     media_format.sample_bytes = supported_format.sample_bytes;
+    media_format.bitrate = supported_format.bitrate;
   }
   return fill_and_encode_entity_info(media_player, msg, conn, remaining_size);
 }

esphome/components/api/api_pb2.cpp

@@ -484,6 +484,7 @@ uint8_t *ListEntitiesCoverResponse::encode_msg(const void *self, uint8_t *__rest
   pos = ProtoEncode::encode_uint32(pos PROTO_ENCODE_DEBUG_ARG, 13, msg.device_id);
 #endif
   pos = ProtoEncode::encode_bool(pos PROTO_ENCODE_DEBUG_ARG, 14, msg.supports_stop_tilt);
+  pos = ProtoEncode::encode_bool(pos PROTO_ENCODE_DEBUG_ARG, 15, msg.supports_toggle);
   return pos;
 }
 uint32_t ListEntitiesCoverResponse::calc_size_msg(const void *self) {
@@ -506,6 +507,7 @@ uint32_t ListEntitiesCoverResponse::calc_size_msg(const void *self) {
   size += ProtoSize::calc_uint32(1, msg.device_id);
 #endif
   size += ProtoSize::calc_bool(1, msg.supports_stop_tilt);
+  size += ProtoSize::calc_bool(1, msg.supports_toggle);
   return size;
 }
 uint8_t *CoverStateResponse::encode_msg(const void *self, uint8_t *__restrict__ pos PROTO_ENCODE_DEBUG_PARAM) {
@@ -565,6 +567,9 @@ void CoverCommandRequest::decode_field(void *self, uint32_t tag, const uint8_t *
     case proto_tag(10, WIRE_TYPE_VARINT):
       msg.stop_tilt = value.as_bool();
       break;
+    case proto_tag(11, WIRE_TYPE_VARINT):
+      msg.toggle = value.as_bool();
+      break;
     default:
       break;
   }
@@ -1364,6 +1369,12 @@ uint8_t *ListEntitiesServicesArgument::encode_msg(const void *self,
 #endif
 #ifdef USE_API_USER_DEFINED_ACTION_METADATA
   pos = ProtoEncode::encode_progmem_string(pos PROTO_ENCODE_DEBUG_ARG, 4, msg.example);
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS
+  pos = ProtoEncode::encode_bool(pos PROTO_ENCODE_DEBUG_ARG, 5, msg.optional);
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS
+  pos = ProtoEncode::encode_progmem_string(pos PROTO_ENCODE_DEBUG_ARG, 6, msg.default_value);
 #endif
   return pos;
 }
@@ -1377,6 +1388,12 @@ uint32_t ListEntitiesServicesArgument::calc_size_msg(const void *self) {
 #endif
 #ifdef USE_API_USER_DEFINED_ACTION_METADATA
   size += ProtoSize::calc_length(1, msg.example.size());
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS
+  size += ProtoSize::calc_bool(1, msg.optional);
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS
+  size += ProtoSize::calc_length(1, msg.default_value.size());
 #endif
   return size;
 }
@@ -2368,6 +2385,7 @@ uint8_t *MediaPlayerSupportedFormat::encode_msg(const void *self, uint8_t *__res
   pos = ProtoEncode::encode_uint32(pos PROTO_ENCODE_DEBUG_ARG, 3, msg.num_channels);
   pos = ProtoEncode::encode_uint32(pos PROTO_ENCODE_DEBUG_ARG, 4, static_cast<uint32_t>(msg.purpose));
   pos = ProtoEncode::encode_uint32(pos PROTO_ENCODE_DEBUG_ARG, 5, msg.sample_bytes);
+  pos = ProtoEncode::encode_uint32(pos PROTO_ENCODE_DEBUG_ARG, 6, msg.bitrate);
   return pos;
 }
 uint32_t MediaPlayerSupportedFormat::calc_size_msg(const void *self) {
@@ -2378,6 +2396,7 @@ uint32_t MediaPlayerSupportedFormat::calc_size_msg(const void *self) {
   size += ProtoSize::calc_uint32(1, msg.num_channels);
   size += msg.purpose ? 2 : 0;
   size += ProtoSize::calc_uint32(1, msg.sample_bytes);
+  size += ProtoSize::calc_uint32(1, msg.bitrate);
   return size;
 }
 uint8_t *ListEntitiesMediaPlayerResponse::encode_msg(const void *self,

esphome/components/api/api_pb2.h

@@ -911,7 +911,7 @@ class BinarySensorStateResponse final : public StateResponseProtoMessage {
 class ListEntitiesCoverResponse final : public InfoResponseProtoMessage {
  public:
   static constexpr uint16_t MESSAGE_TYPE = 13;
-  static constexpr uint8_t ESTIMATED_SIZE = 59;
+  static constexpr uint8_t ESTIMATED_SIZE = 61;
 #ifdef HAS_PROTO_MESSAGE_DUMP
   const LogString *message_name() const override { return LOG_STR("list_entities_cover_response"); }
 #endif
@@ -921,6 +921,7 @@ class ListEntitiesCoverResponse final : public InfoResponseProtoMessage {
   ProgmemStringRef device_class{};
   bool supports_stop{false};
   bool supports_stop_tilt{false};
+  bool supports_toggle{false};
   static uint8_t *encode_msg(const void *self, uint8_t *pos PROTO_ENCODE_DEBUG_PARAM);
   uint8_t *encode(ProtoWriteBuffer &buffer PROTO_ENCODE_DEBUG_PARAM) const {
     return encode_msg(this, buffer.get_pos() PROTO_ENCODE_DEBUG_ARG);
@@ -958,7 +959,7 @@ class CoverStateResponse final : public StateResponseProtoMessage {
 class CoverCommandRequest final : public CommandProtoMessage {
  public:
   static constexpr uint16_t MESSAGE_TYPE = 30;
-  static constexpr uint8_t ESTIMATED_SIZE = 27;
+  static constexpr uint8_t ESTIMATED_SIZE = 29;
 #ifdef HAS_PROTO_MESSAGE_DUMP
   const LogString *message_name() const override { return LOG_STR("cover_command_request"); }
 #endif
@@ -968,6 +969,7 @@ class CoverCommandRequest final : public CommandProtoMessage {
   float tilt{0.0f};
   bool stop{false};
   bool stop_tilt{false};
+  bool toggle{false};
   void decode(const uint8_t *buffer, size_t length) {
     ProtoDecodableMessage::decode_fields(this, buffer, length, &decode_field);
   }
@@ -1591,6 +1593,12 @@ class ListEntitiesServicesArgument final : public ProtoMessage {
 #endif
 #ifdef USE_API_USER_DEFINED_ACTION_METADATA
   ProgmemStringRef example{};
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS
+  bool optional{false};
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS
+  ProgmemStringRef default_value{};
 #endif
   static uint8_t *encode_msg(const void *self, uint8_t *pos PROTO_ENCODE_DEBUG_PARAM);
   uint8_t *encode(ProtoWriteBuffer &buffer PROTO_ENCODE_DEBUG_PARAM) const {
@@ -2261,6 +2269,7 @@ class MediaPlayerSupportedFormat final : public ProtoMessage {
   uint32_t num_channels{0};
   enums::MediaPlayerFormatPurpose purpose{};
   uint32_t sample_bytes{0};
+  uint32_t bitrate{0};
   static uint8_t *encode_msg(const void *self, uint8_t *pos PROTO_ENCODE_DEBUG_PARAM);
   uint8_t *encode(ProtoWriteBuffer &buffer PROTO_ENCODE_DEBUG_PARAM) const {
     return encode_msg(this, buffer.get_pos() PROTO_ENCODE_DEBUG_ARG);

esphome/components/api/api_pb2_dump.cpp

@@ -1246,6 +1246,7 @@ const char *ListEntitiesCoverResponse::dump_to(DumpBuffer &out) const {
   dump_field(out, ESPHOME_PSTR("device_id"), this->device_id);
 #endif
   dump_field(out, ESPHOME_PSTR("supports_stop_tilt"), this->supports_stop_tilt);
+  dump_field(out, ESPHOME_PSTR("supports_toggle"), this->supports_toggle);
   return out.c_str();
 }
 const char *CoverStateResponse::dump_to(DumpBuffer &out) const {
@@ -1271,6 +1272,7 @@ const char *CoverCommandRequest::dump_to(DumpBuffer &out) const {
   dump_field(out, ESPHOME_PSTR("device_id"), this->device_id);
 #endif
   dump_field(out, ESPHOME_PSTR("stop_tilt"), this->stop_tilt);
+  dump_field(out, ESPHOME_PSTR("toggle"), this->toggle);
   return out.c_str();
 }
 #endif
@@ -1641,6 +1643,12 @@ const char *ListEntitiesServicesArgument::dump_to(DumpBuffer &out) const {
 #endif
 #ifdef USE_API_USER_DEFINED_ACTION_METADATA
   dump_progmem_string_field(out, ESPHOME_PSTR("example"), this->example);
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS
+  dump_field(out, ESPHOME_PSTR("optional"), this->optional);
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS
+  dump_progmem_string_field(out, ESPHOME_PSTR("default_value"), this->default_value);
 #endif
   return out.c_str();
 }
@@ -2097,6 +2105,7 @@ const char *MediaPlayerSupportedFormat::dump_to(DumpBuffer &out) const {
   dump_field(out, ESPHOME_PSTR("num_channels"), this->num_channels);
   dump_field(out, ESPHOME_PSTR("purpose"), static_cast<enums::MediaPlayerFormatPurpose>(this->purpose));
   dump_field(out, ESPHOME_PSTR("sample_bytes"), this->sample_bytes);
+  dump_field(out, ESPHOME_PSTR("bitrate"), this->bitrate);
   return out.c_str();
 }
 const char *ListEntitiesMediaPlayerResponse::dump_to(DumpBuffer &out) const {

esphome/components/api/proto.h

@@ -301,7 +301,7 @@ constexpr uint32_t VARINT_MAX_1_BYTE = 1 << 7;   // 128
 constexpr uint32_t VARINT_MAX_2_BYTE = 1 << 14;  // 16384
 
 /// Generated encode body: writes the fields at pos, returns the cursor past them.
-using ProtoEncodeFn = uint8_t *(*) (const void *, uint8_t *PROTO_ENCODE_DEBUG_PARAM);
+using ProtoEncodeFn = uint8_t *(*)(const void *, uint8_t *PROTO_ENCODE_DEBUG_PARAM);
 
 /// Static encode helpers for the generated encode bodies. Each takes the write cursor by value and
 /// returns it advanced, so outlined calls at -Os chain through the return register instead of a

esphome/components/api/user_services.cpp

@@ -31,6 +31,13 @@ ListEntitiesServicesResponse UserServiceStatic::encode_list_service_response_(
 #ifdef USE_API_USER_DEFINED_ACTION_METADATA
     arg.description = this->str_(base + 1);
     arg.example = this->str_(base + 2);
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS
+    // The default slot doubles as the optional flag: nullptr is required, "" optional without a default
+    const char *d = progmem_read_ptr(&this->strings_[base + USER_ACTION_ARG_BASE_STRINGS]);
+    arg.optional = d != nullptr;
+    if (d != nullptr)
+      arg.default_value = ProgmemStringRef(d, ESPHOME_strlen_P(d));
 #endif
   }
   return msg;

esphome/components/api/user_services.h

@@ -40,13 +40,20 @@ template<typename T> enums::ServiceArgType to_service_arg_type();
 // All strings live in one PROGMEM pointer table emitted by codegen (see _action_strings in
 // __init__.py), so each service costs a single pointer of RAM. Layout: the action name, then
 // each argument name; with USE_API_USER_DEFINED_ACTION_METADATA the action description follows
-// the name and every argument is (name, description, example). Unset metadata is nullptr.
+// the name and every argument is (name, description, example); with
+// USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS every argument ends with its default: nullptr for a
+// required argument, "" for an optional one without a default. Unset is nullptr.
 #ifdef USE_API_USER_DEFINED_ACTION_METADATA
 static constexpr size_t USER_ACTION_HEADER_STRINGS = 2;
-static constexpr size_t USER_ACTION_ARG_STRINGS = 3;
+static constexpr size_t USER_ACTION_ARG_BASE_STRINGS = 3;
 #else
 static constexpr size_t USER_ACTION_HEADER_STRINGS = 1;
-static constexpr size_t USER_ACTION_ARG_STRINGS = 1;
+static constexpr size_t USER_ACTION_ARG_BASE_STRINGS = 1;
+#endif
+#ifdef USE_API_USER_DEFINED_ACTION_OPTIONAL_ARGS
+static constexpr size_t USER_ACTION_ARG_STRINGS = USER_ACTION_ARG_BASE_STRINGS + 1;
+#else
+static constexpr size_t USER_ACTION_ARG_STRINGS = USER_ACTION_ARG_BASE_STRINGS;
 #endif
 class UserServiceStatic : public UserServiceDescriptor {
  public:

esphome/components/bl0906/constants.h

@@ -111,10 +111,9 @@ static const uint8_t BL0906_USR_WRPROT = 0x9E;
 // Reset Register
 static const uint8_t BL0906_SOFT_RESET = 0x9F;
 
-const uint8_t BL0906_INIT[2][6] = {
-    // Reset to default
-    {BL0906_WRITE_COMMAND, BL0906_SOFT_RESET, 0x5A, 0x5A, 0x5A, 0x52},
-    // Enable User Operation Write
-    {BL0906_WRITE_COMMAND, BL0906_USR_WRPROT, 0x55, 0x55, 0x00, 0xB7}};
+const uint8_t BL0906_INIT[2][6] = {// Reset to default
+                                   {BL0906_WRITE_COMMAND, BL0906_SOFT_RESET, 0x5A, 0x5A, 0x5A, 0x52},
+                                   // Enable User Operation Write
+                                   {BL0906_WRITE_COMMAND, BL0906_USR_WRPROT, 0x55, 0x55, 0x00, 0xB7}};
 
 }  // namespace esphome::bl0906

esphome/components/cc1101/__init__.py

@@ -295,11 +295,6 @@ async def to_code(config):
         )
 
 
-# Actions
-SendPacketAction = ns.class_(
-    "SendPacketAction", automation.Action, cg.Parented.template(CC1101Component)
-)
-
 CC1101_ACTION_SCHEMA = cv.Schema(
     maybe_simple_id({cv.GenerateID(CONF_ID): cv.use_id(CC1101Component)})
 )
@@ -338,23 +333,11 @@ SEND_PACKET_ACTION_SCHEMA = cv.maybe_simple_value(
 )
 
 
-@automation.register_action(
+automation.register_apply_action(
     "cc1101.send_packet",
-    SendPacketAction,
     SEND_PACKET_ACTION_SCHEMA,
-    synchronous=True,
+    automation.ApplyBytes(CONF_DATA, "transmit_packet({})"),
 )
-async def send_packet_action_to_code(config, action_id, template_arg, args):
-    var = cg.new_Pvariable(action_id, template_arg)
-    await cg.register_parented(var, config[CONF_ID])
-    await automation.templatable_bytes(
-        config[CONF_DATA],
-        args,
-        var.set_data_template,
-        var.set_data_static,
-        "cc1101_data",
-    )
-    return var
 
 
 _CONFIG_VALIDATORS = {opt.schema: validator for opt, validator in CONFIG_MAP.items()}

esphome/components/cc1101/cc1101.h

@@ -132,13 +132,4 @@ class CC1101Component final : public Component,
   bool enter_tx_();
 };
 
-// Action Wrappers
-template<typename... Ts> class SendPacketAction final : public Action<Ts...>, public Parented<CC1101Component> {
-  TEMPLATABLE_BYTES(data)
-
-  void play(const Ts &...x) override {
-    this->data_.visit([this](const uint8_t *data, size_t len) { this->parent_->transmit_packet(data, len); }, x...);
-  }
-};
-
 }  // namespace esphome::cc1101

esphome/components/ch422g/ch422g.cpp

@@ -1,4 +1,5 @@
 #include "ch422g.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 namespace esphome::ch422g {
@@ -59,11 +60,7 @@ bool CH422GComponent::digital_read(uint8_t pin) {
 }
 
 void CH422GComponent::digital_write(uint8_t pin, bool value) {
-  if (value) {
-    this->output_bits_ |= (1 << pin);
-  } else {
-    this->output_bits_ &= ~(1 << pin);
-  }
+  assign_bits(this->output_bits_, 1 << pin, value);
   this->write_outputs_();
 }
 

esphome/components/ch423/ch423.cpp

@@ -1,4 +1,5 @@
 #include "ch423.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include "esphome/core/progmem.h"
 
@@ -62,11 +63,7 @@ bool CH423Component::digital_read(uint8_t pin) {
 }
 
 void CH423Component::digital_write(uint8_t pin, bool value) {
-  if (value) {
-    this->output_bits_ |= (1 << pin);
-  } else {
-    this->output_bits_ &= ~(1 << pin);
-  }
+  assign_bits(this->output_bits_, 1 << pin, value);
   this->write_outputs_();
 }
 

esphome/components/climate/climate.h

@@ -79,6 +79,10 @@ class ClimateCall {
   ClimateCall &set_fan_mode(optional<std::string> fan_mode);
   /// Set the custom fan mode of the climate device.
   ClimateCall &set_fan_mode(const char *custom_fan_mode);
+  /// Set the custom fan mode of the climate device (StringRef overload to resolve ambiguity, zero-copy).
+  ClimateCall &set_fan_mode(StringRef custom_fan_mode) {
+    return this->set_fan_mode(custom_fan_mode.c_str(), custom_fan_mode.size());
+  }
   /// Set the custom fan mode of the climate device (zero-copy API path).
   ClimateCall &set_fan_mode(const char *custom_fan_mode, size_t len);
   /// Set the swing mode of the climate device.
@@ -99,6 +103,10 @@ class ClimateCall {
   ClimateCall &set_preset(optional<std::string> preset);
   /// Set the custom preset of the climate device.
   ClimateCall &set_preset(const char *custom_preset);
+  /// Set the custom preset of the climate device (StringRef overload to resolve ambiguity, zero-copy).
+  ClimateCall &set_preset(StringRef custom_preset) {
+    return this->set_preset(custom_preset.c_str(), custom_preset.size());
+  }
   /// Set the custom preset of the climate device (zero-copy API path).
   ClimateCall &set_preset(const char *custom_preset, size_t len);
 

esphome/components/copy/lock/copy_lock.cpp

@@ -8,10 +8,7 @@ ESPHOME_LOG_TAG(TAG, "copy.lock");
 void CopyLock::setup() {
   source_->add_on_state_callback([this](lock::LockState state) { this->publish_state(state); });
 
-  traits.set_assumed_state(source_->traits.get_assumed_state());
-  traits.set_requires_code(source_->traits.get_requires_code());
-  traits.set_supported_states_mask(source_->traits.get_supported_states_mask());
-  traits.set_supports_open(source_->traits.get_supports_open());
+  this->traits = this->source_->traits;
 
   this->publish_state(source_->state);
 }

esphome/components/cover/cover_traits.h

@@ -1,31 +1,37 @@
 #pragma once
 
+#include <cstdint>
+
 namespace esphome::cover {
 
 class CoverTraits {
  public:
   CoverTraits() = default;
 
-  bool get_is_assumed_state() const { return this->is_assumed_state_; }
-  void set_is_assumed_state(bool is_assumed_state) { this->is_assumed_state_ = is_assumed_state; }
-  bool get_supports_position() const { return this->supports_position_; }
-  void set_supports_position(bool supports_position) { this->supports_position_ = supports_position; }
-  bool get_supports_tilt() const { return this->supports_tilt_; }
-  void set_supports_tilt(bool supports_tilt) { this->supports_tilt_ = supports_tilt; }
-  bool get_supports_toggle() const { return this->supports_toggle_; }
-  void set_supports_toggle(bool supports_toggle) { this->supports_toggle_ = supports_toggle; }
-  bool get_supports_stop() const { return this->supports_stop_; }
-  void set_supports_stop(bool supports_stop) { this->supports_stop_ = supports_stop; }
-  bool get_supports_stop_tilt() const { return this->supports_stop_tilt_; }
-  void set_supports_stop_tilt(bool supports_stop_tilt) { this->supports_stop_tilt_ = supports_stop_tilt; }
+  bool get_is_assumed_state() const { return this->flags_.is_assumed_state; }
+  void set_is_assumed_state(bool is_assumed_state) { this->flags_.is_assumed_state = is_assumed_state; }
+  bool get_supports_position() const { return this->flags_.supports_position; }
+  void set_supports_position(bool supports_position) { this->flags_.supports_position = supports_position; }
+  bool get_supports_tilt() const { return this->flags_.supports_tilt; }
+  void set_supports_tilt(bool supports_tilt) { this->flags_.supports_tilt = supports_tilt; }
+  bool get_supports_toggle() const { return this->flags_.supports_toggle; }
+  void set_supports_toggle(bool supports_toggle) { this->flags_.supports_toggle = supports_toggle; }
+  bool get_supports_stop() const { return this->flags_.supports_stop; }
+  void set_supports_stop(bool supports_stop) { this->flags_.supports_stop = supports_stop; }
+  bool get_supports_stop_tilt() const { return this->flags_.supports_stop_tilt; }
+  void set_supports_stop_tilt(bool supports_stop_tilt) { this->flags_.supports_stop_tilt = supports_stop_tilt; }
 
  protected:
-  bool is_assumed_state_{false};
-  bool supports_position_{false};
-  bool supports_tilt_{false};
-  bool supports_toggle_{false};
-  bool supports_stop_{false};
-  bool supports_stop_tilt_{false};
+  // Bit-packed flags to save memory (1 byte instead of 6)
+  struct CoverTraitFlags {
+    uint8_t is_assumed_state : 1;
+    uint8_t supports_position : 1;
+    uint8_t supports_tilt : 1;
+    uint8_t supports_toggle : 1;
+    uint8_t supports_stop : 1;
+    uint8_t supports_stop_tilt : 1;
+    uint8_t reserved : 2;
+  } flags_{};
 };
 
 }  // namespace esphome::cover

esphome/components/cw2017/__init__.py

@@ -0,0 +1,2 @@
+CODEOWNERS = ["@exciton"]
+DOMAIN = "cw2017"

esphome/components/cw2017/cw2017.cpp

@@ -0,0 +1,196 @@
+#include "cw2017.h"
+
+#include <cstring>
+
+#include "esphome/core/hal.h"
+#include "esphome/core/log.h"
+
+#ifdef USE_DEEP_SLEEP
+#include "esphome/components/deep_sleep/deep_sleep_component.h"
+#endif
+
+namespace esphome::cw2017 {
+
+ESPHOME_LOG_TAG(TAG, "cw2017");
+
+static constexpr uint8_t REG_VERSION = 0x00;
+static constexpr uint8_t REG_VCELL = 0x02;
+static constexpr uint8_t REG_SOC = 0x04;
+static constexpr uint8_t REG_MODE = 0x08;
+static constexpr uint8_t REG_SOC_ALERT = 0x0B;
+static constexpr uint8_t REG_BATINFO = 0x10;
+
+static constexpr uint8_t MODE_NORMAL = 0x00;
+static constexpr uint8_t MODE_SLEEP = 0x30;
+static constexpr uint8_t UPDATE_FLAG = 0x80;
+static constexpr uint8_t RESTART_MODES[] PROGMEM = {0xF0, MODE_SLEEP, MODE_NORMAL};
+static constexpr uint8_t RESTART_STEPS = sizeof(RESTART_MODES);
+
+static constexpr uint16_t VCELL_MASK = 0x3FFF;
+static constexpr float VCELL_VOLTS_PER_LSB = 312.5e-6f;
+
+static constexpr uint32_t STEP_DELAY_MS = 20;
+static constexpr uint32_t READY_POLL_MS = 100;
+static constexpr uint8_t READY_ATTEMPTS = 40;
+static constexpr uint32_t INIT_RETRY_MS = 1000;
+static constexpr uint8_t INIT_ATTEMPTS = 3;
+
+static bool version_is_running(uint8_t version) { return (version & 0xFD) == 0x0D; }
+
+// The configured profile only changes with new firmware, and flashing never ends in a deep-sleep wake.
+static bool woke_from_deep_sleep() {
+#ifdef USE_DEEP_SLEEP
+  return deep_sleep::woke_from_deep_sleep();
+#else
+  return false;
+#endif
+}
+
+bool CW2017::read_profile_matches_(bool &matches) {
+  uint8_t stored[PROFILE_SIZE];
+  uint8_t expected[PROFILE_SIZE];
+  if (!this->read_bytes(REG_BATINFO, stored, PROFILE_SIZE))
+    return false;
+  progmem_memcpy(expected, this->profile_, PROFILE_SIZE);
+  matches = std::memcmp(stored, expected, PROFILE_SIZE) == 0;
+  return true;
+}
+
+bool CW2017::upload_profile_() {
+  // Built here with the register first, so the bus layer does not heap-allocate a buffer this size.
+  uint8_t buffer[1 + PROFILE_SIZE] = {REG_BATINFO};
+  progmem_memcpy(buffer + 1, this->profile_, PROFILE_SIZE);
+  return this->write(buffer, sizeof(buffer)) == i2c::ERROR_OK && this->write_byte(REG_SOC_ALERT, UPDATE_FLAG);
+}
+
+void CW2017::setup() { this->init_(); }
+
+// Retried because another device resetting on the same bus can disturb an early transfer.
+void CW2017::init_failed_(const LogString *reason) {
+  if (++this->init_attempts_ >= INIT_ATTEMPTS) {
+    this->mark_failed(reason);
+    return;
+  }
+  this->set_timeout(INIT_RETRY_MS, [this]() { this->init_(); });
+}
+
+void CW2017::init_() {
+  // A profile upload only takes effect after a restart, so a failed restart is retried, not skipped.
+  if (this->restart_pending_) {
+    this->restart_();
+    return;
+  }
+
+  uint8_t mode = 0;
+  uint8_t version = 0;
+  uint8_t config = 0;
+  if (!this->read_byte(REG_MODE, &mode) || !this->read_byte(REG_VERSION, &version) ||
+      !this->read_byte(REG_SOC_ALERT, &config)) {
+    this->init_failed_(LOG_STR(ESP_LOG_MSG_COMM_FAIL));
+    return;
+  }
+  const bool has_profile = (config & UPDATE_FLAG) != 0;
+  bool matches = has_profile && woke_from_deep_sleep();
+  if (has_profile && !matches && !this->read_profile_matches_(matches)) {
+    this->init_failed_(LOG_STR(ESP_LOG_MSG_COMM_FAIL));
+    return;
+  }
+
+  if (!matches) {
+    ESP_LOGI(TAG, "Uploading battery profile");
+    if (!this->upload_profile_()) {
+      this->init_failed_(LOG_STR("Battery profile upload failed"));
+      return;
+    }
+    this->restart_();
+    return;
+  }
+
+  if (mode == MODE_SLEEP) {
+    // The gauge keeps its profile and state through its own sleep, so a wake is a mode write, not a restart.
+    if (!this->write_byte(REG_MODE, MODE_NORMAL)) {
+      this->init_failed_(LOG_STR("Gauge wake failed"));
+      return;
+    }
+    this->set_timeout(STEP_DELAY_MS, [this]() { this->wait_ready_(0); });
+    return;
+  }
+
+  if (mode != MODE_NORMAL || !version_is_running(version)) {
+    this->restart_();
+    return;
+  }
+
+  this->wait_ready_(0);
+}
+
+void CW2017::restart_() {
+  this->restart_pending_ = true;
+  this->set_timeout(STEP_DELAY_MS, [this]() { this->restart_step_(0); });
+}
+
+void CW2017::restart_step_(uint8_t step) {
+  if (!this->write_byte(REG_MODE, progmem_read_byte(&RESTART_MODES[step]))) {
+    this->init_failed_(LOG_STR("Restart failed"));
+    return;
+  }
+  if (step + 1 < RESTART_STEPS) {
+    this->set_timeout(STEP_DELAY_MS, [this, step]() { this->restart_step_(step + 1); });
+  } else {
+    this->restart_pending_ = false;
+    this->set_timeout(STEP_DELAY_MS, [this]() { this->wait_ready_(0); });
+  }
+}
+
+void CW2017::wait_ready_(uint8_t attempt) {
+  uint8_t version = 0;
+  uint8_t soc = 0;
+  if (this->read_byte(REG_VERSION, &version) && version_is_running(version) && this->read_byte(REG_SOC, &soc) &&
+      soc <= 100) {
+    ESP_LOGD(TAG, "Gauge ready %u ms after boot", (unsigned) millis());
+    this->ready_ = true;
+    this->update();
+    return;
+  }
+  if (attempt + 1 >= READY_ATTEMPTS) {
+    this->init_failed_(LOG_STR("Gauge did not become ready"));
+    return;
+  }
+  this->set_timeout(READY_POLL_MS, [this, attempt]() { this->wait_ready_(attempt + 1); });
+}
+
+void CW2017::update() {
+  if (!this->ready_)
+    return;
+
+  if (this->battery_level_sensor_ != nullptr) {
+    uint8_t soc = 0;
+    if (this->read_byte(REG_SOC, &soc) && soc <= 100) {
+      this->battery_level_sensor_->publish_state(soc);
+    } else {
+      this->status_set_warning();
+      return;
+    }
+  }
+
+  if (this->battery_voltage_sensor_ != nullptr) {
+    uint16_t raw = 0;
+    if (this->read_byte_16(REG_VCELL, &raw)) {
+      this->battery_voltage_sensor_->publish_state((raw & VCELL_MASK) * VCELL_VOLTS_PER_LSB);
+    } else {
+      this->status_set_warning();
+      return;
+    }
+  }
+  this->status_clear_warning();
+}
+
+void CW2017::dump_config() {
+  ESP_LOGCONFIG(TAG, "CW2017:");
+  LOG_I2C_DEVICE(this);
+  LOG_UPDATE_INTERVAL(this);
+  LOG_SENSOR("  ", "Battery Level", this->battery_level_sensor_);
+  LOG_SENSOR("  ", "Battery Voltage", this->battery_voltage_sensor_);
+}
+
+}  // namespace esphome::cw2017

esphome/components/cw2017/cw2017.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include "esphome/components/i2c/i2c.h"
+#include "esphome/components/sensor/sensor.h"
+#include "esphome/core/component.h"
+
+namespace esphome::cw2017 {
+
+static constexpr uint8_t PROFILE_SIZE = 80;
+
+class CW2017 : public PollingComponent, public i2c::I2CDevice {
+ public:
+  explicit CW2017(const uint8_t *profile) : profile_(profile) {}
+
+  void set_battery_level_sensor(sensor::Sensor *sensor) { this->battery_level_sensor_ = sensor; }
+  void set_battery_voltage_sensor(sensor::Sensor *sensor) { this->battery_voltage_sensor_ = sensor; }
+
+  void setup() override;
+  void update() override;
+  void dump_config() override;
+
+ protected:
+  void init_();
+  void init_failed_(const LogString *reason);
+  bool read_profile_matches_(bool &matches);
+  bool upload_profile_();
+  void restart_();
+  void restart_step_(uint8_t step);
+  void wait_ready_(uint8_t attempt);
+
+  const uint8_t *profile_;
+  sensor::Sensor *battery_level_sensor_{nullptr};
+  sensor::Sensor *battery_voltage_sensor_{nullptr};
+  bool ready_{false};
+  bool restart_pending_{false};
+  uint8_t init_attempts_{0};
+};
+
+}  // namespace esphome::cw2017

esphome/components/cw2017/sensor.py

@@ -0,0 +1,61 @@
+import esphome.codegen as cg
+from esphome.components import i2c, sensor
+import esphome.config_validation as cv
+from esphome.const import (
+    CONF_BATTERY_LEVEL,
+    CONF_BATTERY_VOLTAGE,
+    CONF_RAW_DATA_ID,
+    DEVICE_CLASS_BATTERY,
+    DEVICE_CLASS_VOLTAGE,
+    ENTITY_CATEGORY_DIAGNOSTIC,
+    STATE_CLASS_MEASUREMENT,
+    UNIT_PERCENT,
+    UNIT_VOLT,
+)
+from esphome.types import ConfigType
+
+DEPENDENCIES = ["i2c"]
+
+CONF_BATTERY_PROFILE = "battery_profile"
+PROFILE_SIZE = 80
+
+cw2017_ns = cg.esphome_ns.namespace("cw2017")
+CW2017 = cw2017_ns.class_("CW2017", cg.PollingComponent, i2c.I2CDevice)
+
+CONFIG_SCHEMA = (
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.declare_id(CW2017),
+            cv.GenerateID(CONF_RAW_DATA_ID): cv.declare_id(cg.uint8),
+            cv.Required(CONF_BATTERY_PROFILE): cv.All(
+                cv.ensure_list(cv.hex_uint8_t),
+                cv.Length(min=PROFILE_SIZE, max=PROFILE_SIZE),
+            ),
+            cv.Optional(CONF_BATTERY_LEVEL): sensor.sensor_schema(
+                unit_of_measurement=UNIT_PERCENT,
+                accuracy_decimals=0,
+                device_class=DEVICE_CLASS_BATTERY,
+                state_class=STATE_CLASS_MEASUREMENT,
+                entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
+            ),
+            cv.Optional(CONF_BATTERY_VOLTAGE): sensor.sensor_schema(
+                unit_of_measurement=UNIT_VOLT,
+                accuracy_decimals=3,
+                device_class=DEVICE_CLASS_VOLTAGE,
+                state_class=STATE_CLASS_MEASUREMENT,
+                entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
+            ),
+        }
+    )
+    .extend(cv.polling_component_schema("60s"))
+    .extend(i2c.i2c_device_schema(0x63))
+)
+
+
+async def to_code(config: ConfigType) -> None:
+    profile = cg.progmem_array(config[CONF_RAW_DATA_ID], config[CONF_BATTERY_PROFILE])
+    var = await i2c.new_i2c_component(config, profile)
+
+    sensors = sensor.sub_sensors(config)
+    await sensors(CONF_BATTERY_LEVEL, var.set_battery_level_sensor)
+    await sensors(CONF_BATTERY_VOLTAGE, var.set_battery_voltage_sensor)

esphome/components/deep_sleep/deep_sleep_bk72xx.cpp

@@ -7,7 +7,6 @@ namespace esphome::deep_sleep {
 
 ESPHOME_LOG_TAG(TAG, "deep_sleep");
 
-#ifdef USE_DEEP_SLEEP_ON_WAKE
 WakeupCause get_wakeup_cause() {
   switch (lt_get_reboot_reason()) {
     case REBOOT_REASON_SLEEP_GPIO:
@@ -20,7 +19,6 @@ WakeupCause get_wakeup_cause() {
       return WAKEUP_CAUSE_NONE;
   }
 }
-#endif  // USE_DEEP_SLEEP_ON_WAKE
 
 optional<uint32_t> DeepSleepComponent::get_run_duration_() const { return this->run_duration_; }
 

esphome/components/deep_sleep/deep_sleep_component.h

@@ -60,8 +60,6 @@ struct WakeupCauseToRunDuration {
 
 #endif  // USE_ESP32
 
-#ifdef USE_DEEP_SLEEP_ON_WAKE
-
 /// Why the device woke from deep sleep. Passed to on_wake automations.
 enum WakeupCause : uint8_t {
   /// The device did not wake from deep sleep (for example a cold boot, reset or OTA restart).
@@ -79,6 +77,11 @@ enum WakeupCause : uint8_t {
 /// Return why the device woke from deep sleep. Implemented per platform.
 WakeupCause get_wakeup_cause();
 
+/// Return true when this boot is a wake from deep sleep.
+inline bool woke_from_deep_sleep() { return get_wakeup_cause() != WAKEUP_CAUSE_NONE; }
+
+#ifdef USE_DEEP_SLEEP_ON_WAKE
+
 /** Setup priority of on_wake triggers.
  *
  * Between restoring global variables (setup_priority::HARDWARE, 800) and on_boot automations at

esphome/components/deep_sleep/deep_sleep_esp32.cpp

@@ -30,7 +30,6 @@ namespace esphome::deep_sleep {
 
 ESPHOME_LOG_TAG(TAG, "deep_sleep");
 
-#ifdef USE_DEEP_SLEEP_ON_WAKE
 WakeupCause get_wakeup_cause() {
   switch (esp_sleep_get_wakeup_cause()) {
     case ESP_SLEEP_WAKEUP_EXT0:
@@ -47,7 +46,6 @@ WakeupCause get_wakeup_cause() {
       return WAKEUP_CAUSE_UNKNOWN;
   }
 }
-#endif  // USE_DEEP_SLEEP_ON_WAKE
 
 optional<uint32_t> DeepSleepComponent::get_run_duration_() const {
   if (this->wakeup_cause_to_run_duration_.has_value()) {

esphome/components/deep_sleep/deep_sleep_esp8266.cpp

@@ -3,17 +3,14 @@
 
 #include <Esp.h>
 
-#ifdef USE_DEEP_SLEEP_ON_WAKE
 extern "C" {
 #include <user_interface.h>
 }
-#endif
 
 namespace esphome::deep_sleep {
 
 ESPHOME_LOG_TAG(TAG, "deep_sleep");
 
-#ifdef USE_DEEP_SLEEP_ON_WAKE
 WakeupCause get_wakeup_cause() {
   // The ESP8266 can only wake from deep sleep through the RTC timer (via GPIO16 -> RST).
   // NOLINTNEXTLINE(readability-static-accessed-through-instance)
@@ -22,7 +19,6 @@ WakeupCause get_wakeup_cause() {
   }
   return WAKEUP_CAUSE_NONE;
 }
-#endif  // USE_DEEP_SLEEP_ON_WAKE
 
 optional<uint32_t> DeepSleepComponent::get_run_duration_() const { return this->run_duration_; }
 

esphome/components/deep_sleep/deep_sleep_zephyr.cpp

@@ -31,6 +31,9 @@ static bool wakeable_delay_feed_wdt(uint32_t ms) {
   return false;
 }
 
+// A wake from System OFF is not told apart from a reset yet.
+WakeupCause get_wakeup_cause() { return WAKEUP_CAUSE_NONE; }
+
 optional<uint32_t> DeepSleepComponent::get_run_duration_() const { return this->run_duration_; }
 
 void DeepSleepComponent::dump_config_platform_() {}

esphome/components/ds3231/__init__.py

@@ -1,7 +1,18 @@
-from esphome import automation
+from esphome import automation, pins
 import esphome.codegen as cg
 from esphome.components import i2c
+from esphome.components.const import CONF_ENABLED
 import esphome.config_validation as cv
+from esphome.const import (
+    CONF_FREQUENCY,
+    CONF_HOUR,
+    CONF_INTERRUPT_PIN,
+    CONF_MINUTE,
+    CONF_MODE,
+    CONF_OFFSET,
+    CONF_SECOND,
+    CONF_STATE,
+)
 from esphome.types import ConfigType
 
 CODEOWNERS = ["@linkedupbits"]
@@ -10,23 +21,245 @@ MULTI_CONF = True
 DOMAIN = "ds3231"
 
 CONF_DS3231_ID = "ds3231_id"
+CONF_ALARM = "alarm"
+CONF_ALARM_CHECK_INTERVAL = "alarm_check_interval"
+CONF_AGING_OFFSET = "aging_offset"
+CONF_AUTO_CLEAR_ALARMS = "auto_clear_alarms"
+CONF_BATTERY_BACKED_SQUARE_WAVE = "battery_backed_square_wave"
+CONF_DAY_OF_MONTH = "day_of_month"
+CONF_DAY_OF_WEEK = "day_of_week"
+CONF_ON_ALARM_1 = "on_alarm_1"
+CONF_ON_ALARM_2 = "on_alarm_2"
+CONF_OUTPUT_32KHZ = "output_32khz"
+CONF_SQUARE_WAVE_FREQUENCY = "square_wave_frequency"
 
 ds3231_ns = cg.esphome_ns.namespace("ds3231")
 DS3231Component = ds3231_ns.class_("DS3231Component", cg.Component, i2c.I2CDevice)
 
-CONFIG_SCHEMA = (
-    cv.Schema({cv.GenerateID(): cv.declare_id(DS3231Component)})
+AlarmMode = ds3231_ns.enum("AlarmMode")
+ALARM_1_MODES = AlarmMode.options(
+    "every_second",
+    "every_minute",
+    "hourly",
+    "daily",
+    "monthly",
+    "weekly",
+    prefix="ALARM_MODE_",
+)
+# Alarm 2 has no seconds register.
+ALARM_2_MODES = {k: v for k, v in ALARM_1_MODES.items() if k != "every_second"}
+
+SquareWaveFrequency = ds3231_ns.enum("SquareWaveFrequency")
+# Keyed by the frequency in Hz; cv.frequency turns "1024Hz", "1.024kHz" or 1024 into it.
+SQUARE_WAVE_FREQUENCIES = {
+    1: SquareWaveFrequency.SQUARE_WAVE_1HZ,
+    1024: SquareWaveFrequency.SQUARE_WAVE_1024HZ,
+    4096: SquareWaveFrequency.SQUARE_WAVE_4096HZ,
+    8192: SquareWaveFrequency.SQUARE_WAVE_8192HZ,
+}
+validate_square_wave_frequency = cv.All(
+    cv.frequency, cv.enum(SQUARE_WAVE_FREQUENCIES, int=True)
+)
+
+validate_aging_offset = cv.int_range(min=-128, max=127)
+
+CONFIG_SCHEMA = cv.All(
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.declare_id(DS3231Component),
+            cv.Optional(CONF_INTERRUPT_PIN): pins.internal_gpio_input_pin_schema,
+            cv.Optional(CONF_SQUARE_WAVE_FREQUENCY): validate_square_wave_frequency,
+            cv.Optional(CONF_BATTERY_BACKED_SQUARE_WAVE): cv.boolean,
+            cv.Optional(CONF_OUTPUT_32KHZ): cv.boolean,
+            cv.Optional(CONF_AGING_OFFSET): validate_aging_offset,
+            cv.Optional(CONF_AUTO_CLEAR_ALARMS, default=True): cv.boolean,
+            cv.Optional(
+                CONF_ALARM_CHECK_INTERVAL, default="1s"
+            ): cv.positive_time_period_milliseconds,
+            cv.Optional(CONF_ON_ALARM_1): automation.validate_automation(single=True),
+            cv.Optional(CONF_ON_ALARM_2): automation.validate_automation(single=True),
+        }
+    )
     .extend(cv.COMPONENT_SCHEMA)
-    .extend(i2c.i2c_device_schema(0x68))
+    .extend(i2c.i2c_device_schema(0x68)),
+    cv.has_at_most_one_key(CONF_INTERRUPT_PIN, CONF_SQUARE_WAVE_FREQUENCY),
 )
 
 
 async def to_code(config: ConfigType) -> None:
-    await i2c.new_i2c_component(config)
+    var = await i2c.new_i2c_component(config)
 
+    await cg.add_pin(var.set_interrupt_pin, config.get(CONF_INTERRUPT_PIN))
+    cg.add_optional(
+        var.set_square_wave_frequency, config.get(CONF_SQUARE_WAVE_FREQUENCY)
+    )
+    cg.add_optional(
+        var.set_battery_backed_square_wave, config.get(CONF_BATTERY_BACKED_SQUARE_WAVE)
+    )
+    cg.add_optional(var.set_output_32khz_config, config.get(CONF_OUTPUT_32KHZ))
+    cg.add_optional(var.set_aging_offset_config, config.get(CONF_AGING_OFFSET))
+    cg.add(var.set_auto_clear_alarms(config[CONF_AUTO_CLEAR_ALARMS]))
+    cg.add(var.set_alarm_check_interval(config[CONF_ALARM_CHECK_INTERVAL]))
+    # The alarm flags are only read when something uses them; the binary sensor platform
+    # turns this on as well. With an interrupt pin the check also releases INT/SQW.
+    if any(
+        key in config for key in (CONF_INTERRUPT_PIN, CONF_ON_ALARM_1, CONF_ON_ALARM_2)
+    ):
+        cg.add(var.set_monitor_alarms(True))
+
+    # One callback for both alarms; each automation runs only for its own alarm number.
+    for conf_key, alarm in ((CONF_ON_ALARM_1, 1), (CONF_ON_ALARM_2, 2)):
+        if (conf := config.get(conf_key)) is not None:
+            await automation.build_callback_automation(
+                var,
+                "add_on_alarm_callback",
+                [],
+                conf,
+                params=[(cg.uint8, "alarm")],
+                forward=[],
+                when=f"alarm == {alarm}",
+            )
+
+
+# ---------------------------------------------------------------------------------------------
+# Actions
+# ---------------------------------------------------------------------------------------------
+
+DS3231_ACTION_SCHEMA = automation.maybe_simple_id(
+    {cv.GenerateID(): cv.use_id(DS3231Component)}
+)
 
 automation.register_apply_action(
     "ds3231.force_temperature_conversion",
-    automation.maybe_simple_id({cv.GenerateID(): cv.use_id(DS3231Component)}),
+    DS3231_ACTION_SCHEMA,
     automation.ApplyCall("force_temperature_conversion()"),
 )
+
+
+def _validate_alarm_day(config: ConfigType) -> ConfigType:
+    mode = config[CONF_MODE]
+    if mode == "monthly" and CONF_DAY_OF_MONTH not in config:
+        raise cv.Invalid(f"'{CONF_DAY_OF_MONTH}' is required in monthly mode")
+    if mode == "weekly" and CONF_DAY_OF_WEEK not in config:
+        raise cv.Invalid(f"'{CONF_DAY_OF_WEEK}' is required in weekly mode")
+    # The unused day still has to be a valid register value.
+    config.setdefault(CONF_DAY_OF_MONTH, 1)
+    config.setdefault(CONF_DAY_OF_WEEK, 1)
+    return config
+
+
+def _alarm_schema(modes: dict, with_second: bool) -> cv.Schema:
+    schema = {
+        cv.GenerateID(): cv.use_id(DS3231Component),
+        cv.Required(CONF_MODE): cv.enum(modes, lower=True),
+        cv.Optional(CONF_MINUTE, default=0): cv.templatable(
+            cv.int_range(min=0, max=59)
+        ),
+        cv.Optional(CONF_HOUR, default=0): cv.templatable(cv.int_range(min=0, max=23)),
+        cv.Optional(CONF_DAY_OF_MONTH): cv.templatable(cv.int_range(min=1, max=31)),
+        # 1 = Sunday ... 7 = Saturday, as in ESPHome's time component.
+        cv.Optional(CONF_DAY_OF_WEEK): cv.templatable(cv.int_range(min=1, max=7)),
+        cv.Optional(CONF_ENABLED, default=True): cv.templatable(cv.boolean),
+    }
+    if with_second:
+        schema[cv.Optional(CONF_SECOND, default=0)] = cv.templatable(
+            cv.int_range(min=0, max=59)
+        )
+    return cv.All(cv.Schema(schema), _validate_alarm_day)
+
+
+automation.register_apply_action(
+    "ds3231.set_alarm_1",
+    _alarm_schema(ALARM_1_MODES, with_second=True),
+    automation.ApplyCall(
+        "set_alarm_1({}, {}, {}, {}, {}, {}, {})",
+        (
+            (CONF_MODE, AlarmMode),
+            (CONF_SECOND, cg.uint8),
+            (CONF_MINUTE, cg.uint8),
+            (CONF_HOUR, cg.uint8),
+            (CONF_DAY_OF_MONTH, cg.uint8),
+            (CONF_DAY_OF_WEEK, cg.uint8),
+            (CONF_ENABLED, cg.bool_),
+        ),
+    ),
+)
+
+automation.register_apply_action(
+    "ds3231.set_alarm_2",
+    _alarm_schema(ALARM_2_MODES, with_second=False),
+    automation.ApplyCall(
+        "set_alarm_2({}, {}, {}, {}, {}, {})",
+        (
+            (CONF_MODE, AlarmMode),
+            (CONF_MINUTE, cg.uint8),
+            (CONF_HOUR, cg.uint8),
+            (CONF_DAY_OF_MONTH, cg.uint8),
+            (CONF_DAY_OF_WEEK, cg.uint8),
+            (CONF_ENABLED, cg.bool_),
+        ),
+    ),
+)
+
+DS3231_ALARM_ACTION_SCHEMA = cv.Schema(
+    {
+        cv.GenerateID(): cv.use_id(DS3231Component),
+        cv.Required(CONF_ALARM): cv.templatable(cv.int_range(min=1, max=2)),
+    }
+)
+
+for _name, _method in (
+    ("ds3231.enable_alarm", "enable_alarm"),
+    ("ds3231.disable_alarm", "disable_alarm"),
+    ("ds3231.clear_alarm", "clear_alarm"),
+):
+    automation.register_apply_action(
+        _name,
+        DS3231_ALARM_ACTION_SCHEMA,
+        automation.ApplyField(CONF_ALARM, _method, cg.uint8),
+    )
+
+automation.register_apply_condition(
+    "ds3231.is_alarm_triggered",
+    DS3231_ALARM_ACTION_SCHEMA,
+    automation.ApplyCall("is_alarm_triggered({})", ((CONF_ALARM, cg.uint8),)),
+)
+
+automation.register_apply_action(
+    "ds3231.enable_square_wave",
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.use_id(DS3231Component),
+            cv.Required(CONF_FREQUENCY): validate_square_wave_frequency,
+        }
+    ),
+    automation.ApplyField(CONF_FREQUENCY, "enable_square_wave", SquareWaveFrequency),
+)
+
+automation.register_apply_action(
+    "ds3231.disable_square_wave",
+    DS3231_ACTION_SCHEMA,
+    automation.ApplyCall("disable_square_wave()"),
+)
+
+automation.register_apply_action(
+    "ds3231.set_32khz_output",
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.use_id(DS3231Component),
+            cv.Required(CONF_STATE): cv.templatable(cv.boolean),
+        }
+    ),
+    automation.ApplyField(CONF_STATE, "set_output_32khz", cg.bool_),
+)
+
+automation.register_apply_action(
+    "ds3231.set_aging_offset",
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.use_id(DS3231Component),
+            cv.Required(CONF_OFFSET): cv.templatable(validate_aging_offset),
+        }
+    ),
+    automation.ApplyField(CONF_OFFSET, "set_aging_offset", cg.int8),
+)

esphome/components/ds3231/binary_sensor/__init__.py

@@ -0,0 +1,47 @@
+import esphome.codegen as cg
+from esphome.components import binary_sensor
+import esphome.config_validation as cv
+from esphome.const import CONF_ID, DEVICE_CLASS_PROBLEM, ENTITY_CATEGORY_DIAGNOSTIC
+from esphome.types import ConfigType
+
+from .. import CONF_DS3231_ID, DS3231Component
+
+DEPENDENCIES = ["ds3231"]
+
+CONF_ALARM_1 = "alarm_1"
+CONF_ALARM_2 = "alarm_2"
+CONF_OSCILLATOR_STOPPED = "oscillator_stopped"
+
+ICON_ALARM = "mdi:alarm"
+
+CONFIG_SCHEMA = cv.All(
+    cv.Schema(
+        {
+            cv.GenerateID(CONF_ID): cv.declare_id(cg.EntityBase),
+            cv.GenerateID(CONF_DS3231_ID): cv.use_id(DS3231Component),
+            cv.Optional(CONF_ALARM_1): binary_sensor.binary_sensor_schema(
+                icon=ICON_ALARM
+            ),
+            cv.Optional(CONF_ALARM_2): binary_sensor.binary_sensor_schema(
+                icon=ICON_ALARM
+            ),
+            cv.Optional(CONF_OSCILLATOR_STOPPED): binary_sensor.binary_sensor_schema(
+                device_class=DEVICE_CLASS_PROBLEM,
+                entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
+            ),
+        }
+    ),
+    cv.has_at_least_one_key(CONF_ALARM_1, CONF_ALARM_2, CONF_OSCILLATOR_STOPPED),
+)
+
+
+async def to_code(config: ConfigType) -> None:
+    hub = await cg.get_variable(config[CONF_DS3231_ID])
+    binary_sensors = binary_sensor.sub_binary_sensors(config)
+    await binary_sensors(CONF_ALARM_1, hub.set_alarm_1_binary_sensor)
+    await binary_sensors(CONF_ALARM_2, hub.set_alarm_2_binary_sensor)
+    await binary_sensors(
+        CONF_OSCILLATOR_STOPPED, hub.set_oscillator_stopped_binary_sensor
+    )
+    if CONF_ALARM_1 in config or CONF_ALARM_2 in config:
+        cg.add(hub.set_monitor_alarms(True))

esphome/components/ds3231/ds3231.cpp

@@ -9,29 +9,184 @@ namespace esphome::ds3231 {
 
 ESPHOME_LOG_TAG(TAG, "ds3231");
 
+static constexpr uint8_t DS3231_REG_SECONDS = 0x00;
+static constexpr uint8_t DS3231_REG_ALARM_1 = 0x07;
+static constexpr uint8_t DS3231_REG_ALARM_2 = 0x0B;
 static constexpr uint8_t DS3231_REG_CONTROL = 0x0E;
+static constexpr uint8_t DS3231_REG_STATUS = 0x0F;
+static constexpr uint8_t DS3231_REG_AGING_OFFSET = 0x10;
 static constexpr uint8_t DS3231_REG_TEMPERATURE = 0x11;
 
+static constexpr uint8_t ALARM_MASK_BIT = 0x80;     // AxMy: this register is ignored when matching
+static constexpr uint8_t ALARM_DAY_OF_WEEK = 0x40;  // DY/DT: match day of week instead of date
+
+/// How long an alarm binary sensor stays on when the flag is cleared automatically.
+static constexpr uint32_t ALARM_PULSE_MS = 1000;
+
+static const LogString *alarm_state_to_string(uint8_t control, uint8_t alarm) {
+  return (control & (alarm == 1 ? 0x01 : 0x02)) != 0 ? LOG_STR("enabled") : LOG_STR("disabled");
+}
+
+static const LogString *square_wave_to_string(SquareWaveFrequency frequency) {
+  switch (frequency) {
+    case SQUARE_WAVE_1HZ:
+      return LOG_STR("1 Hz");
+    case SQUARE_WAVE_1024HZ:
+      return LOG_STR("1.024 kHz");
+    case SQUARE_WAVE_4096HZ:
+      return LOG_STR("4.096 kHz");
+    case SQUARE_WAVE_8192HZ:
+      return LOG_STR("8.192 kHz");
+    default:
+      return LOG_STR("unknown");
+  }
+}
+
+void IRAM_ATTR DS3231Component::interrupt_handler(DS3231Component *arg) { arg->enable_loop_soon_any_context(); }
+
 void DS3231Component::setup() {
   if (!this->read_control_status_()) {
     this->mark_failed(LOG_STR(ESP_LOG_MSG_COMM_FAIL));
     return;
   }
 
-  this->control_reg_ &= ~CONTROL_EOSC;  // keep the oscillator running on battery
-  // INT/SQW is the (unused) interrupt line rather than a square-wave output.
-  this->control_reg_ |= CONTROL_INTCN;
-  if (!this->write_control_()) {
+  // Keep the oscillator running on battery. INT/SQW is the alarm interrupt line unless a square
+  // wave is configured. The alarm interrupt enables (A1IE/A2IE) are kept as they are: the alarms
+  // live on the chip and survive a reboot of the ESP on battery.
+  uint8_t mask = CONTROL_EOSC | CONTROL_INTCN;
+  uint8_t value = CONTROL_INTCN;
+  if (this->square_wave_configured_) {
+    mask |= CONTROL_RS_MASK;
+    value = this->square_wave_frequency_ << CONTROL_RS_SHIFT;
+  }
+  if (this->battery_backed_square_wave_ >= 0) {
+    mask |= CONTROL_BBSQW;
+    assign_bits(value, CONTROL_BBSQW, this->battery_backed_square_wave_ != 0);
+  }
+  if (!this->update_control_(mask, value)) {
     this->mark_failed(LOG_STR(ESP_LOG_MSG_COMM_FAIL));
     return;
   }
+
+  if (this->output_32khz_ >= 0) {
+    assign_bits(this->status_reg_, STATUS_EN32KHZ, this->output_32khz_ != 0);
+    if (!this->write_status_(0)) {
+      this->mark_failed(LOG_STR(ESP_LOG_MSG_COMM_FAIL));
+      return;
+    }
+  }
+
+  if (this->aging_offset_configured_ && !this->write_aging_offset_(this->aging_offset_)) {
+    this->mark_failed(LOG_STR(ESP_LOG_MSG_COMM_FAIL));
+    return;
+  }
+
+  if ((this->status_reg_ & STATUS_OSF) != 0) {
+    ESP_LOGW(TAG, "Oscillator was stopped (battery empty or missing?), the stored time is invalid.");
+  }
+  this->publish_oscillator_stopped_();
+
+  if (!this->monitor_alarms_) {
+    this->disable_loop();
+    return;
+  }
+
+  // Start from a known state; an alarm that fired while the ESP was off is picked up by the first
+  // check, which runs from the loop right after setup.
+  this->publish_alarm_state_(1, false);
+  this->publish_alarm_state_(2, false);
+
+  if (this->interrupt_pin_ != nullptr) {
+    this->interrupt_pin_->setup();
+    // INT/SQW is open drain and active low: a falling edge means an enabled alarm matched.
+    // The handler only wakes the loop; the flags are read from there.
+    this->interrupt_pin_->attach_interrupt(&DS3231Component::interrupt_handler, this, gpio::INTERRUPT_FALLING_EDGE);
+  }
+  // Without an interrupt pin this is how alarms are seen. With one it is a fallback: it picks up an
+  // edge that was missed, and latched flags (auto_clear_alarms: false) that were cleared elsewhere.
+  this->set_interval(this->alarm_check_interval_, [this]() { this->check_alarms_(); });
+}
+
+void DS3231Component::loop() {
+  // Only runs once after setup and when woken by the interrupt pin.
+  this->disable_loop();
+  this->check_alarms_();
 }
 
 void DS3231Component::dump_config() {
   ESP_LOGCONFIG(TAG, "DS3231:");
   LOG_I2C_DEVICE(this);
+  if (this->is_failed())
+    return;
+  LOG_PIN("  Interrupt Pin: ", this->interrupt_pin_);
+  if ((this->control_reg_ & CONTROL_INTCN) == 0) {
+    ESP_LOGCONFIG(TAG, "  INT/SQW: square wave %s",
+                  LOG_STR_ARG(square_wave_to_string(
+                      static_cast<SquareWaveFrequency>((this->control_reg_ & CONTROL_RS_MASK) >> CONTROL_RS_SHIFT))));
+  } else {
+    ESP_LOGCONFIG(TAG, "  INT/SQW: alarm interrupt");
+  }
+  ESP_LOGCONFIG(TAG,
+                "  Battery-backed square wave: %s\n"
+                "  32 kHz output: %s\n"
+                "  Alarm 1: %s\n"
+                "  Alarm 2: %s\n"
+                "  Auto clear alarms: %s",
+                YESNO(this->control_reg_ & CONTROL_BBSQW), ONOFF(this->status_reg_ & STATUS_EN32KHZ),
+                LOG_STR_ARG(alarm_state_to_string(this->control_reg_, 1)),
+                LOG_STR_ARG(alarm_state_to_string(this->control_reg_, 2)), YESNO(this->auto_clear_alarms_));
+  if (this->aging_offset_configured_) {
+    ESP_LOGCONFIG(TAG, "  Aging offset: %d", this->aging_offset_);
+  }
+  if (this->monitor_alarms_) {
+    ESP_LOGCONFIG(TAG, "  Alarm check interval: %" PRIu32 " ms", this->alarm_check_interval_);
+  }
+#ifdef USE_BINARY_SENSOR
+  LOG_BINARY_SENSOR("  ", "Alarm 1", this->alarm_1_binary_sensor_);
+  LOG_BINARY_SENSOR("  ", "Alarm 2", this->alarm_2_binary_sensor_);
+  LOG_BINARY_SENSOR("  ", "Oscillator Stopped", this->oscillator_stopped_binary_sensor_);
+#endif
 }
 
+// ---------------------------------------------------------------------------------------------
+// Clock
+// ---------------------------------------------------------------------------------------------
+
+bool DS3231Component::read_calendar(uint8_t *raw) {
+  if (this->is_failed() || !this->status_comm_result(this->read_bytes(DS3231_REG_SECONDS, raw, CALENDAR_LEN)))
+    return false;
+  // Without a valid status the oscillator-stop flag is unknown, so the time can't be trusted.
+  if (!this->read_control_status_())
+    return false;
+  this->publish_oscillator_stopped_();
+  if ((this->status_reg_ & STATUS_OSF) != 0) {
+    ESP_LOGW(TAG, "Oscillator stop flag set, the RTC time is invalid. Write a valid time first.");
+    return false;
+  }
+  return true;
+}
+
+bool DS3231Component::write_calendar(const uint8_t *raw) {
+  if (this->is_failed() || !this->status_comm_result(this->write_bytes(DS3231_REG_SECONDS, raw, CALENDAR_LEN)))
+    return false;
+
+  // The time is valid again: clear the oscillator stop flag. If that fails, the RTC would keep
+  // reporting its time as invalid, so the write is not reported as successful.
+  if (!this->read_control_status_())
+    return false;
+  if ((this->status_reg_ & STATUS_OSF) != 0) {
+    if (!this->write_status_(STATUS_OSF))
+      return false;
+    this->status_reg_ &= ~STATUS_OSF;
+  }
+  this->publish_oscillator_stopped_();
+  return true;
+}
+
+// ---------------------------------------------------------------------------------------------
+// Temperature
+// ---------------------------------------------------------------------------------------------
+
 bool DS3231Component::read_temperature(float &out) {
   uint8_t raw[2];
   if (this->is_failed() || !this->read_bytes(DS3231_REG_TEMPERATURE, raw, sizeof(raw))) {
@@ -53,26 +208,280 @@ void DS3231Component::force_temperature_conversion() {
     ESP_LOGW(TAG, "A temperature conversion is already in progress.");
     return;
   }
-  this->control_reg_ |= CONTROL_CONV;
-  this->write_control_();
+  // CONV is a one-shot command bit, so it is not kept in the cached value.
+  this->status_comm_result(this->write_byte(DS3231_REG_CONTROL, this->control_reg_ | CONTROL_CONV));
 }
 
+// ---------------------------------------------------------------------------------------------
+// Alarms
+// ---------------------------------------------------------------------------------------------
+
+void DS3231Component::set_alarm_1(AlarmMode mode, uint8_t second, uint8_t minute, uint8_t hour, uint8_t day_of_month,
+                                  uint8_t day_of_week, bool enabled) {
+  if (second > 59 || minute > 59 || hour > 23 || day_of_month < 1 || day_of_month > 31 || day_of_week < 1 ||
+      day_of_week > 7 || mode > ALARM_MODE_WEEKLY) {
+    ESP_LOGE(TAG, "Invalid alarm 1 setting.");
+    return;
+  }
+  // Mask bits A1M1..A1M4: a set bit means the register is ignored when matching.
+  uint8_t regs[4] = {
+      uint8_to_bcd(second),
+      uint8_to_bcd(minute),
+      uint8_to_bcd(hour),
+      mode == ALARM_MODE_WEEKLY ? static_cast<uint8_t>(ALARM_DAY_OF_WEEK | day_of_week) : uint8_to_bcd(day_of_month),
+  };
+  switch (mode) {
+    case ALARM_MODE_EVERY_SECOND:
+      regs[0] |= ALARM_MASK_BIT;
+      [[fallthrough]];
+    case ALARM_MODE_EVERY_MINUTE:
+      regs[1] |= ALARM_MASK_BIT;
+      [[fallthrough]];
+    case ALARM_MODE_HOURLY:
+      regs[2] |= ALARM_MASK_BIT;
+      [[fallthrough]];
+    case ALARM_MODE_DAILY:
+      regs[3] |= ALARM_MASK_BIT;
+      break;
+    default:  // MONTHLY / WEEKLY: everything matches
+      break;
+  }
+  ESP_LOGD(TAG, "Setting alarm 1: mode %u, %02u:%02u:%02u, day of month %u, day of week %u, %s", mode, hour, minute,
+           second, day_of_month, day_of_week, enabled ? LOG_STR_LITERAL("enabled") : LOG_STR_LITERAL("disabled"));
+  this->write_alarm_(1, regs, sizeof(regs), enabled);
+}
+
+void DS3231Component::set_alarm_2(AlarmMode mode, uint8_t minute, uint8_t hour, uint8_t day_of_month,
+                                  uint8_t day_of_week, bool enabled) {
+  if (minute > 59 || hour > 23 || day_of_month < 1 || day_of_month > 31 || day_of_week < 1 || day_of_week > 7 ||
+      mode == ALARM_MODE_EVERY_SECOND || mode > ALARM_MODE_WEEKLY) {
+    ESP_LOGE(TAG, "Invalid alarm 2 setting.");
+    return;
+  }
+  // Mask bits A2M2..A2M4.
+  uint8_t regs[3] = {
+      uint8_to_bcd(minute),
+      uint8_to_bcd(hour),
+      mode == ALARM_MODE_WEEKLY ? static_cast<uint8_t>(ALARM_DAY_OF_WEEK | day_of_week) : uint8_to_bcd(day_of_month),
+  };
+  switch (mode) {
+    case ALARM_MODE_EVERY_MINUTE:
+      regs[0] |= ALARM_MASK_BIT;
+      [[fallthrough]];
+    case ALARM_MODE_HOURLY:
+      regs[1] |= ALARM_MASK_BIT;
+      [[fallthrough]];
+    case ALARM_MODE_DAILY:
+      regs[2] |= ALARM_MASK_BIT;
+      break;
+    default:  // MONTHLY / WEEKLY: everything matches
+      break;
+  }
+  ESP_LOGD(TAG, "Setting alarm 2: mode %u, %02u:%02u, day of month %u, day of week %u, %s", mode, hour, minute,
+           day_of_month, day_of_week, enabled ? LOG_STR_LITERAL("enabled") : LOG_STR_LITERAL("disabled"));
+  this->write_alarm_(2, regs, sizeof(regs), enabled);
+}
+
+void DS3231Component::write_alarm_(uint8_t alarm, const uint8_t *regs, size_t len, bool enabled) {
+  if (this->is_failed())
+    return;
+  if (!this->status_comm_result(this->write_bytes(alarm == 1 ? DS3231_REG_ALARM_1 : DS3231_REG_ALARM_2, regs, len)))
+    return;
+  // Changing the registers may have matched on the way: start from a clean flag. Enabling the
+  // alarm with a stale flag would assert INT/SQW right away.
+  if (!this->clear_alarm_flag_(alarm)) {
+    ESP_LOGW(TAG, "Alarm %u written, but its flag could not be cleared; not changing its enable.", alarm);
+    return;
+  }
+  this->set_alarm_enabled_(alarm, enabled);
+}
+
+void DS3231Component::set_alarm_enabled_(uint8_t alarm, bool enabled) {
+  if (alarm != 1 && alarm != 2) {
+    ESP_LOGE(TAG, "Invalid alarm number %u.", alarm);
+    return;
+  }
+  if (this->is_failed())
+    return;
+  const uint8_t bit = alarm == 1 ? CONTROL_A1IE : CONTROL_A2IE;
+  if (!this->update_control_(bit, enabled ? bit : 0))
+    return;
+  if (enabled && (this->control_reg_ & CONTROL_INTCN) == 0) {
+    ESP_LOGW(TAG, "Alarm %u enabled, but INT/SQW is a square-wave output: only the flag will be set.", alarm);
+  }
+  ESP_LOGD(TAG, "Alarm %u %s.", alarm, enabled ? LOG_STR_LITERAL("enabled") : LOG_STR_LITERAL("disabled"));
+}
+
+void DS3231Component::enable_alarm(uint8_t alarm) {
+  // The chip sets the flag on every match even while the alarm is disabled; enabling with it set
+  // would fire the trigger (and INT/SQW) for that old match right away.
+  if (this->clear_alarm_flag_(alarm))
+    this->set_alarm_enabled_(alarm, true);
+}
+
+void DS3231Component::clear_alarm(uint8_t alarm) { this->clear_alarm_flag_(alarm); }
+
+bool DS3231Component::clear_alarm_flag_(uint8_t alarm) {
+  if (alarm != 1 && alarm != 2) {
+    ESP_LOGE(TAG, "Invalid alarm number %u.", alarm);
+    return false;
+  }
+  if (this->is_failed() || !this->read_control_status_())
+    return false;
+  const uint8_t flag = alarm == 1 ? STATUS_A1F : STATUS_A2F;
+  if ((this->status_reg_ & flag) != 0) {
+    // On failure the flag is still set on the chip: keep reporting the alarm as it is.
+    if (!this->write_status_(flag))
+      return false;
+    this->status_reg_ &= ~flag;
+  }
+  this->alarm_active_[alarm - 1] = false;
+  this->publish_alarm_state_(alarm, false);
+  return true;
+}
+
+bool DS3231Component::is_alarm_triggered(uint8_t alarm) {
+  if (this->is_failed() || !this->read_control_status_())
+    return false;
+  return (this->status_reg_ & (alarm == 1 ? STATUS_A1F : STATUS_A2F)) != 0;
+}
+
+void DS3231Component::check_alarms_() {
+  if (this->is_failed() || !this->read_control_status_())
+    return;
+  this->publish_oscillator_stopped_();
+
+  uint8_t to_clear = 0;
+  for (uint8_t alarm = 1; alarm <= 2; alarm++) {
+    const uint8_t flag = alarm == 1 ? STATUS_A1F : STATUS_A2F;
+    const uint8_t enable = alarm == 1 ? CONTROL_A1IE : CONTROL_A2IE;
+    const bool triggered = (this->status_reg_ & flag) != 0;
+    const bool enabled = (this->control_reg_ & enable) != 0;
+    bool &active = this->alarm_active_[alarm - 1];
+
+    if (!triggered) {
+      if (active && !this->auto_clear_alarms_)
+        this->publish_alarm_state_(alarm, false);
+      active = false;
+      continue;
+    }
+    // The flag is set on every match even when the alarm is disabled; only enabled alarms count.
+    if (enabled && !active) {
+      ESP_LOGI(TAG, "Alarm %u triggered.", alarm);
+      active = true;
+      this->publish_alarm_state_(alarm, true);
+      this->alarm_callback_.call(alarm);
+    }
+    if (this->auto_clear_alarms_)
+      to_clear |= flag;
+  }
+
+  if (to_clear != 0 && this->write_status_(to_clear)) {
+    this->status_reg_ &= ~to_clear;
+    for (uint8_t alarm = 1; alarm <= 2; alarm++) {
+      if ((to_clear & (alarm == 1 ? STATUS_A1F : STATUS_A2F)) == 0 || !this->alarm_active_[alarm - 1])
+        continue;
+      this->alarm_active_[alarm - 1] = false;
+#ifdef USE_BINARY_SENSOR
+      // Keep the binary sensor on long enough for the state to be seen, then turn it off again.
+      this->set_timeout(ALARM_PULSE_TIMEOUT_ID + alarm - 1, ALARM_PULSE_MS,
+                        [this, alarm]() { this->publish_alarm_state_(alarm, false); });
+#endif
+    }
+  }
+}
+
+void DS3231Component::publish_alarm_state_(uint8_t alarm, bool state) {
+#ifdef USE_BINARY_SENSOR
+  auto *sensor = alarm == 1 ? this->alarm_1_binary_sensor_ : this->alarm_2_binary_sensor_;
+  if (sensor != nullptr)
+    sensor->publish_state(state);
+#endif
+}
+
+void DS3231Component::publish_oscillator_stopped_() {
+#ifdef USE_BINARY_SENSOR
+  if (this->oscillator_stopped_binary_sensor_ != nullptr)
+    this->oscillator_stopped_binary_sensor_->publish_state((this->status_reg_ & STATUS_OSF) != 0);
+#endif
+}
+
+// ---------------------------------------------------------------------------------------------
+// Outputs and calibration
+// ---------------------------------------------------------------------------------------------
+
+void DS3231Component::enable_square_wave(SquareWaveFrequency frequency) {
+  if (this->interrupt_pin_ != nullptr) {
+    ESP_LOGE(TAG, "Can't enable the square wave: INT/SQW is used as the alarm interrupt pin.");
+    return;
+  }
+  if (this->is_failed())
+    return;
+  if (this->update_control_(CONTROL_INTCN | CONTROL_RS_MASK, frequency << CONTROL_RS_SHIFT)) {
+    ESP_LOGD(TAG, "Square wave enabled at %s.", LOG_STR_ARG(square_wave_to_string(frequency)));
+  }
+}
+
+void DS3231Component::disable_square_wave() {
+  if (this->is_failed())
+    return;
+  if (this->update_control_(CONTROL_INTCN, CONTROL_INTCN)) {
+    ESP_LOGD(TAG, "Square wave disabled, INT/SQW is the alarm interrupt.");
+  }
+}
+
+void DS3231Component::set_output_32khz(bool enabled) {
+  if (this->is_failed() || !this->read_control_status_())
+    return;
+  assign_bits(this->status_reg_, STATUS_EN32KHZ, enabled);
+  if (this->write_status_(0)) {
+    ESP_LOGD(TAG, "32 kHz output %s.", ONOFF(enabled));
+  }
+}
+
+void DS3231Component::set_aging_offset(int8_t offset) {
+  if (this->is_failed())
+    return;
+  if (!this->write_aging_offset_(offset))
+    return;
+  ESP_LOGD(TAG, "Aging offset set to %d.", offset);
+  // The new offset takes effect with the next temperature conversion.
+  this->force_temperature_conversion();
+}
+
+// ---------------------------------------------------------------------------------------------
+// Register access
+// ---------------------------------------------------------------------------------------------
+
 bool DS3231Component::read_control_status_() {
   uint8_t raw[2];
-  if (!this->read_bytes(DS3231_REG_CONTROL, raw, sizeof(raw))) {
-    ESP_LOGW(TAG, "Can't read control/status registers.");
+  if (!this->status_comm_result(this->read_bytes(DS3231_REG_CONTROL, raw, sizeof(raw))))
     return false;
-  }
-  this->control_reg_ = raw[0];
+  this->control_reg_ = raw[0] & ~CONTROL_CONV;
   this->status_reg_ = raw[1];
   return true;
 }
 
-bool DS3231Component::write_control_() {
-  if (!this->write_byte(DS3231_REG_CONTROL, this->control_reg_)) {
-    ESP_LOGW(TAG, "Can't write control register.");
+bool DS3231Component::update_control_(uint8_t mask, uint8_t value) {
+  // CONV is a one-shot command bit: always write it back as 0 so a control change never starts
+  // a temperature conversion.
+  if (!this->status_comm_result(this->update_register(DS3231_REG_CONTROL, mask | CONTROL_CONV, value)))
     return false;
-  }
+  this->control_reg_ = (this->control_reg_ & ~mask) | (value & mask);
+  return true;
+}
+
+bool DS3231Component::write_status_(uint8_t clear) {
+  // The flags can only be written to 0; writing 1 leaves them unchanged, so a flag that was set
+  // between the read and this write is never lost.
+  const uint8_t value = ((this->status_reg_ & STATUS_EN32KHZ) | STATUS_FLAGS) & ~clear;
+  return this->status_comm_result(this->write_byte(DS3231_REG_STATUS, value));
+}
+
+bool DS3231Component::write_aging_offset_(int8_t offset) {
+  if (!this->status_comm_result(this->write_byte(DS3231_REG_AGING_OFFSET, static_cast<uint8_t>(offset))))
+    return false;
+  this->aging_offset_ = offset;
   return true;
 }
 

esphome/components/ds3231/ds3231.h

@@ -1,32 +1,163 @@
 #pragma once
 
 #include "esphome/core/component.h"
+#include "esphome/core/defines.h"
+#include "esphome/core/hal.h"
+#include "esphome/core/helpers.h"
 #include "esphome/components/i2c/i2c.h"
 
+#ifdef USE_BINARY_SENSOR
+#include "esphome/components/binary_sensor/binary_sensor.h"
+#endif
+
 namespace esphome::ds3231 {
 
+/// When an alarm fires. Alarm 1 supports every mode, alarm 2 has no seconds register and so no EVERY_SECOND.
+enum AlarmMode : uint8_t {
+  ALARM_MODE_EVERY_SECOND = 0,  ///< Alarm 1 only.
+  ALARM_MODE_EVERY_MINUTE,      ///< Alarm 1: when the seconds match. Alarm 2: at second 00 of every minute.
+  ALARM_MODE_HOURLY,            ///< When minutes (and seconds) match.
+  ALARM_MODE_DAILY,             ///< When hours, minutes (and seconds) match.
+  ALARM_MODE_MONTHLY,           ///< When date, hours, minutes (and seconds) match.
+  ALARM_MODE_WEEKLY,            ///< When day of week, hours, minutes (and seconds) match.
+};
+
+/// Frequency of the INT/SQW pin when it is a square-wave output (RS2:RS1 in the control register).
+enum SquareWaveFrequency : uint8_t {
+  SQUARE_WAVE_1HZ = 0,
+  SQUARE_WAVE_1024HZ = 1,
+  SQUARE_WAVE_4096HZ = 2,
+  SQUARE_WAVE_8192HZ = 3,
+};
+
 /// Hub for a single DS3231 real-time clock. Owns all register access; the platforms talk to the
 /// chip through this class.
 class DS3231Component final : public Component, public i2c::I2CDevice {
  public:
+  /// Seconds through year, the 7-byte BCD calendar the time platform decodes with time::DS_BCD_CALENDAR.
+  static constexpr size_t CALENDAR_LEN = 7;
+
   void setup() override;
+  void loop() override;
   void dump_config() override;
 
+  // ---- Configuration (set from codegen) ----
+  void set_interrupt_pin(InternalGPIOPin *pin) { this->interrupt_pin_ = pin; }
+  void set_square_wave_frequency(SquareWaveFrequency frequency) {
+    this->square_wave_frequency_ = frequency;
+    this->square_wave_configured_ = true;
+  }
+  void set_battery_backed_square_wave(bool enabled) { this->battery_backed_square_wave_ = enabled ? 1 : 0; }
+  void set_output_32khz_config(bool enabled) { this->output_32khz_ = enabled ? 1 : 0; }
+  void set_aging_offset_config(int8_t offset) {
+    this->aging_offset_ = offset;
+    this->aging_offset_configured_ = true;
+  }
+  void set_auto_clear_alarms(bool auto_clear) { this->auto_clear_alarms_ = auto_clear; }
+  void set_alarm_check_interval(uint32_t interval) { this->alarm_check_interval_ = interval; }
+  void set_monitor_alarms(bool monitor) { this->monitor_alarms_ = monitor; }
+
+  /// Register a void(uint8_t alarm) callback that runs when an enabled alarm (1 or 2) matches.
+  template<typename F> void add_on_alarm_callback(F &&callback) {
+    this->alarm_callback_.add(std::forward<F>(callback));
+  }
+
+#ifdef USE_BINARY_SENSOR
+  SUB_BINARY_SENSOR(alarm_1)
+  SUB_BINARY_SENSOR(alarm_2)
+  SUB_BINARY_SENSOR(oscillator_stopped)
+#endif
+
+  // ---- Clock registers (used by the time platform) ----
+  /// Read the calendar registers into @p raw. Fails if the oscillator was stopped since the time was last set.
+  bool read_calendar(uint8_t *raw);
+  /// Write the calendar registers from @p raw and clear the oscillator-stop flag.
+  bool write_calendar(const uint8_t *raw);
+
+  // ---- Temperature ----
   bool read_temperature(float &out);
   void force_temperature_conversion();
 
+  // ---- Alarms ----
+  /// Program alarm 1. @p day_of_month is used in MONTHLY mode, @p day_of_week (1 = Sunday) in WEEKLY mode.
+  void set_alarm_1(AlarmMode mode, uint8_t second, uint8_t minute, uint8_t hour, uint8_t day_of_month,
+                   uint8_t day_of_week, bool enabled);
+  /// Program alarm 2 (minute resolution, fires at second 00).
+  void set_alarm_2(AlarmMode mode, uint8_t minute, uint8_t hour, uint8_t day_of_month, uint8_t day_of_week,
+                   bool enabled);
+  /// Enable @p alarm. A match from while it was disabled is cleared first, so only the next one fires.
+  void enable_alarm(uint8_t alarm);
+  void disable_alarm(uint8_t alarm) { this->set_alarm_enabled_(alarm, false); }
+  /// Clear the alarm flag, which also releases the INT/SQW line.
+  void clear_alarm(uint8_t alarm);
+  /// True while the alarm flag of @p alarm (1 or 2) is set on the chip.
+  bool is_alarm_triggered(uint8_t alarm);
+
+  // ---- Outputs and calibration ----
+  /// Switch INT/SQW to a square-wave output at @p frequency. Alarms then no longer drive the pin.
+  void enable_square_wave(SquareWaveFrequency frequency);
+  /// Switch INT/SQW back to the (active-low) alarm interrupt output.
+  void disable_square_wave();
+  void set_output_32khz(bool enabled);
+  /// Aging offset in LSB (about 0.1 ppm each at 25 degC); positive values slow the clock down.
+  void set_aging_offset(int8_t offset);
+
  protected:
+  static constexpr uint8_t CONTROL_A1IE = 0x01;
+  static constexpr uint8_t CONTROL_A2IE = 0x02;
   static constexpr uint8_t CONTROL_INTCN = 0x04;
+  static constexpr uint8_t CONTROL_RS_MASK = 0x18;
+  static constexpr uint8_t CONTROL_RS_SHIFT = 3;
   static constexpr uint8_t CONTROL_CONV = 0x20;
+  static constexpr uint8_t CONTROL_BBSQW = 0x40;
   static constexpr uint8_t CONTROL_EOSC = 0x80;
 
+  static constexpr uint8_t STATUS_A1F = 0x01;
+  static constexpr uint8_t STATUS_A2F = 0x02;
   static constexpr uint8_t STATUS_BSY = 0x04;
+  static constexpr uint8_t STATUS_EN32KHZ = 0x08;
+  static constexpr uint8_t STATUS_OSF = 0x80;
+  static constexpr uint8_t STATUS_FLAGS = STATUS_A1F | STATUS_A2F | STATUS_OSF;
 
+  /// Scheduler ids: one pulse timer per alarm (id + alarm - 1).
+  static constexpr uint32_t ALARM_PULSE_TIMEOUT_ID = 0;
+
+  static void interrupt_handler(DS3231Component *arg);
+
+  /// Read the control and status registers into the cached copies. Sets the warning flag on failure.
   bool read_control_status_();
-  bool write_control_();
+  /// Replace the bits in @p mask of the control register with @p value, on the chip and in the cache.
+  bool update_control_(uint8_t mask, uint8_t value);
+  /// Write the status register, clearing the flags in @p clear (writing 1 to a flag leaves it unchanged).
+  bool write_status_(uint8_t clear);
+  bool write_aging_offset_(int8_t offset);
+  /// Clear the flag of @p alarm and report it off. Returns false (state unchanged) if that fails.
+  bool clear_alarm_flag_(uint8_t alarm);
+  void set_alarm_enabled_(uint8_t alarm, bool enabled);
+  /// Write the alarm registers, clear the stale flag and set the interrupt enable.
+  void write_alarm_(uint8_t alarm, const uint8_t *regs, size_t len, bool enabled);
+  /// Read the flags, fire triggers and update the binary sensors.
+  void check_alarms_();
+  void publish_alarm_state_(uint8_t alarm, bool state);
+  void publish_oscillator_stopped_();
 
+  InternalGPIOPin *interrupt_pin_{nullptr};
+  LazyCallbackManager<void(uint8_t)> alarm_callback_;
+
+  uint32_t alarm_check_interval_{1000};
   uint8_t control_reg_{0};
   uint8_t status_reg_{0};
+  int8_t aging_offset_{0};
+  SquareWaveFrequency square_wave_frequency_{SQUARE_WAVE_1HZ};
+  /// -1: leave the chip as it is, 0: off, 1: on.
+  int8_t battery_backed_square_wave_{-1};
+  int8_t output_32khz_{-1};
+  bool square_wave_configured_{false};
+  bool aging_offset_configured_{false};
+  bool auto_clear_alarms_{true};
+  bool monitor_alarms_{false};
+  /// Set while an alarm flag has been reported, so a latched flag fires its trigger only once.
+  bool alarm_active_[2]{false, false};
 };
 
 }  // namespace esphome::ds3231

esphome/components/ds3231/time/__init__.py

@@ -0,0 +1,40 @@
+from esphome import automation
+import esphome.codegen as cg
+from esphome.components import time
+import esphome.config_validation as cv
+from esphome.const import CONF_ID
+from esphome.types import ConfigType
+
+from .. import CONF_DS3231_ID, DS3231Component, ds3231_ns
+
+DEPENDENCIES = ["ds3231"]
+
+DS3231Time = ds3231_ns.class_(
+    "DS3231Time", time.RealTimeClock, cg.Parented.template(DS3231Component)
+)
+
+CONFIG_SCHEMA = time.TIME_SCHEMA.extend(
+    {
+        cv.GenerateID(): cv.declare_id(DS3231Time),
+        cv.GenerateID(CONF_DS3231_ID): cv.use_id(DS3231Component),
+    }
+)
+
+DS3231_TIME_ACTION_SCHEMA = automation.maybe_simple_id(
+    {cv.GenerateID(): cv.use_id(DS3231Time)}
+)
+
+automation.register_apply_action(
+    "ds3231.write_time", DS3231_TIME_ACTION_SCHEMA, automation.ApplyCall("write_time()")
+)
+
+automation.register_apply_action(
+    "ds3231.read_time", DS3231_TIME_ACTION_SCHEMA, automation.ApplyCall("read_time()")
+)
+
+
+async def to_code(config: ConfigType) -> None:
+    var = cg.new_Pvariable(config[CONF_ID])
+    await cg.register_component(var, config)
+    await cg.register_parented(var, config[CONF_DS3231_ID])
+    await time.register_time(var, config)

esphome/components/ds3231/time/ds3231_time.cpp

@@ -0,0 +1,48 @@
+#include "ds3231_time.h"
+#include "esphome/core/log.h"
+
+namespace esphome::ds3231 {
+
+ESPHOME_LOG_TAG(TAG, "ds3231.time");
+
+void DS3231Time::update() { this->read_time(); }
+
+void DS3231Time::dump_config() {
+  ESP_LOGCONFIG(TAG, "DS3231 Time:");
+  RealTimeClock::dump_config();
+}
+
+void DS3231Time::read_time() {
+  uint8_t raw[DS3231Component::CALENDAR_LEN];
+  if (!this->status_comm_result(this->parent_->read_calendar(raw), LOG_STR("No valid time from the RTC")))
+    return;
+  const ESPTime rtc_time = time::decode_bcd_calendar<time::DS_BCD_CALENDAR>(raw);
+  ESP_LOGD(TAG, "Read UTC time: %04u-%02u-%02u %02u:%02u:%02u (day of week %u)", rtc_time.year, rtc_time.month,
+           rtc_time.day_of_month, rtc_time.hour, rtc_time.minute, rtc_time.second, rtc_time.day_of_week);
+  // The day of week is a free-running counter on the DS3231 and may have been set with a different
+  // numbering by other software, so it is not used to validate the time.
+  if (!this->status_comm_result(rtc_time.is_valid(/*check_day_of_week=*/false, /*check_day_of_year=*/false),
+                                LOG_STR("Invalid RTC time")))
+    return;
+  this->synchronize_epoch_(rtc_time.timestamp);
+}
+
+void DS3231Time::write_time() {
+  auto now = this->utcnow();
+  if (!now.is_valid()) {
+    ESP_LOGE(TAG, "Invalid system time, not syncing to RTC.");
+    return;
+  }
+  if (now.year > 2199) {
+    ESP_LOGE(TAG, "Year %u is out of the DS3231 range (2000-2199).", now.year);
+    return;
+  }
+  uint8_t raw[DS3231Component::CALENDAR_LEN];
+  time::encode_bcd_calendar<time::DS_BCD_CALENDAR>(now, raw);
+  if (!this->status_comm_result(this->parent_->write_calendar(raw)))
+    return;
+  ESP_LOGD(TAG, "Wrote UTC time: %04u-%02u-%02u %02u:%02u:%02u", now.year, now.month, now.day_of_month, now.hour,
+           now.minute, now.second);
+}
+
+}  // namespace esphome::ds3231

esphome/components/ds3231/time/ds3231_time.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/core/helpers.h"
+#include "esphome/components/time/real_time_clock.h"
+
+#include "../ds3231.h"
+
+namespace esphome::ds3231 {
+
+class DS3231Time final : public time::RealTimeClock, public Parented<DS3231Component> {
+ public:
+  void update() override;
+  void dump_config() override;
+
+  /// Set the system clock from the RTC.
+  void read_time();
+  /// Store the system clock in the RTC.
+  void write_time();
+};
+
+}  // namespace esphome::ds3231

esphome/components/duco/__init__.py

@@ -0,0 +1,87 @@
+import esphome.codegen as cg
+from esphome.components import time, uart
+import esphome.config_validation as cv
+from esphome.const import CONF_DISCOVERY, CONF_ID, CONF_TIME, CONF_TIME_ID
+from esphome.core import ID
+from esphome.types import ConfigType
+
+CODEOWNERS = ["@kokx"]
+DEPENDENCIES = ["uart"]
+DOMAIN = "duco"
+MULTI_CONF = True
+
+CONF_DISABLE_CRC = "disable_crc"
+CONF_DUCO_ID = "duco_id"
+
+duco_ns = cg.esphome_ns.namespace("duco")
+Duco = duco_ns.class_("Duco", cg.Component, uart.UARTDevice)
+# Base of every class that sends requests through the hub
+DucoDevice = duco_ns.class_(
+    "DucoDevice", cg.PollingComponent, cg.Parented.template(Duco)
+)
+DucoDiscovery = duco_ns.class_("DucoDiscovery", DucoDevice)
+DucoTime = duco_ns.class_("DucoTime", cg.PollingComponent, cg.Parented.template(Duco))
+
+# Entities of the platforms take the hub with this
+DUCO_COMPONENT_SCHEMA = cv.Schema({cv.GenerateID(CONF_DUCO_ID): cv.use_id(Duco)})
+
+DISCOVERY_SCHEMA = cv.Schema({cv.GenerateID(): cv.declare_id(DucoDiscovery)}).extend(
+    cv.COMPONENT_SCHEMA
+)
+
+TIME_SCHEMA = cv.Schema(
+    {
+        cv.GenerateID(): cv.declare_id(DucoTime),
+        cv.GenerateID(CONF_TIME_ID): cv.use_id(time.RealTimeClock),
+    }
+).extend(cv.polling_component_schema("15min"))
+
+CONFIG_SCHEMA = (
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.declare_id(Duco),
+            cv.Optional(CONF_DISABLE_CRC, default=False): cv.boolean,
+            cv.Optional(CONF_DISCOVERY): DISCOVERY_SCHEMA,
+            cv.Optional(CONF_TIME): TIME_SCHEMA,
+        }
+    )
+    .extend(cv.COMPONENT_SCHEMA)
+    .extend(uart.UART_DEVICE_SCHEMA)
+)
+
+FINAL_VALIDATE_SCHEMA = uart.final_validate_device_schema(
+    DOMAIN,
+    baud_rate=57600,
+    require_tx=True,
+    require_rx=True,
+    data_bits=8,
+    parity="NONE",
+    stop_bits=1,
+)
+
+
+_request_device_slot = cg.slot_counter("DUCO_DEVICE_COUNT")
+
+
+async def register_duco_device(var: cg.MockObj, config: ConfigType, hub_id: ID) -> None:
+    """Register a device that sends requests, and give it an open request slot on its hub."""
+    await cg.register_component(var, config)
+    hub = await cg.get_variable(hub_id)
+    await cg.register_parented(var, hub)
+    _request_device_slot(str(hub_id))
+    cg.add(hub.register_device(var))
+
+
+async def to_code(config: ConfigType) -> None:
+    var = await uart.new_uart_component(config)
+    cg.add(var.set_disable_crc(config[CONF_DISABLE_CRC]))
+
+    if (discovery := config.get(CONF_DISCOVERY)) is not None:
+        discovery_var = cg.new_Pvariable(discovery[CONF_ID])
+        await register_duco_device(discovery_var, discovery, config[CONF_ID])
+
+    if (time_config := config.get(CONF_TIME)) is not None:
+        clock = await cg.get_variable(time_config[CONF_TIME_ID])
+        time_var = cg.new_Pvariable(time_config[CONF_ID], clock)
+        await cg.register_component(time_var, time_config)
+        await cg.register_parented(time_var, var)

esphome/components/duco/duco.cpp

@@ -0,0 +1,273 @@
+#include "duco.h"
+
+#include "esphome/core/application.h"
+#include "esphome/core/log.h"
+
+namespace esphome::duco {
+
+ESPHOME_LOG_TAG(TAG, "duco");
+
+static constexpr uint8_t HEADER_START = 0xAA;
+static constexpr uint8_t HEADER_END = 0x55;
+static constexpr uint8_t STUFFING = 0x01;  // follows an 0xAA inside a message, not part of it
+static constexpr uint32_t FRAME_GAP_MS = 50;
+
+static constexpr uint32_t DISCOVERY_START_ID = 0;
+static constexpr uint32_t DISCOVERY_STEP_ID = 1;
+static constexpr uint32_t DISCOVERY_START_MS = 16000;
+static constexpr uint32_t DISCOVERY_STEP_MS = 1600;
+static constexpr uint8_t DISCOVERY_MAX_ATTEMPTS = 3;
+
+void Duco::loop() {
+  const uint32_t now = App.get_loop_component_start_time();
+  // Read first: after a slow loop pass the rest of a message is already waiting, which is not silence
+  this->read_available([this, now](uint8_t byte) {
+    if (this->parse_byte_(byte)) {
+      this->last_byte_ = now;
+    } else {
+      this->reset_frame_();
+    }
+  });
+
+  // The last message of a burst has no header after it, so it ends on silence
+  if (this->rx_size_ != 0 && now - this->last_byte_ > FRAME_GAP_MS) {
+    this->finalize_message_();
+    this->reset_frame_();
+  }
+}
+
+void Duco::reset_frame_() {
+  this->rx_size_ = 0;
+  this->escaped_ = false;
+}
+
+void Duco::close_request(DucoDevice *device) {
+#ifdef DUCO_DEVICE_COUNT
+  for (auto &pending : this->pending_) {
+    if (pending.device == device) {
+      pending.function = 0;
+      pending.missed = false;
+      this->update_warning_();
+      return;
+    }
+  }
+#endif
+}
+
+bool Duco::parse_byte_(uint8_t byte) {
+  const size_t at = this->rx_size_;
+  if (at >= MAX_FRAME_SIZE) {
+    ESP_LOGV(TAG, "Message longer than %u bytes dropped", static_cast<unsigned>(MAX_FRAME_SIZE));
+    return false;
+  }
+  const uint8_t prev = at > 0 ? this->rx_buffer_[at - 1] : 0;
+
+  if (at == 1 && prev == HEADER_START && byte == HEADER_END)
+    return false;  // header of the next message
+
+  if (at >= 2) {
+    const bool escaped = this->escaped_;
+    this->escaped_ = false;
+    if (prev == HEADER_START && !escaped) {
+      if (byte == STUFFING) {
+        this->escaped_ = true;
+        return true;
+      }
+      if (at >= 3 && byte == HEADER_END) {
+        this->rx_size_--;  // drop the 0xAA of the header
+        this->finalize_message_();
+        return false;
+      }
+    }
+  }
+
+  this->rx_buffer_[this->rx_size_++] = byte;
+  return true;
+}
+
+void Duco::finalize_message_() {
+  const uint8_t *raw = this->rx_buffer_.data();
+  // length (function, id and data), function, id, data, CRC low, CRC high
+  if (this->rx_size_ < 5 || raw[0] < 2 || this->rx_size_ < raw[0] + 3u) {
+    ESP_LOGV(TAG, "Malformed message dropped: %u bytes, length byte %u", this->rx_size_, raw[0]);
+    return;
+  }
+  const uint8_t length = raw[0];
+
+  const uint16_t computed_crc = crc16(raw, length + 1);
+  const uint16_t remote_crc = encode_uint16(raw[length + 2], raw[length + 1]);
+  if (computed_crc != remote_crc) {
+    if (!this->disable_crc_) {
+      ESP_LOGV(TAG, "CRC check failed: %04X != %04X", computed_crc, remote_crc);
+      return;
+    }
+    ESP_LOGV(TAG, "CRC check failed, ignored: %04X != %04X", computed_crc, remote_crc);
+  }
+
+#ifdef DUCO_DEVICE_COUNT
+  // The box first acknowledges a request with function + 1, then answers with function + 2
+  const DucoMessage message{raw[2], raw + 3, static_cast<uint8_t>(length - 2)};
+  for (auto &pending : this->pending_) {
+    if (pending.function != 0 && pending.id == message.id && pending.function + 2 == raw[1]) {
+      pending.function = 0;
+      pending.missed = false;
+      this->update_warning_();
+      pending.device->receive_response(message);
+      return;
+    }
+  }
+  // Acknowledgements (odd function codes) are expected and never match
+  if ((raw[1] & 1) == 0) {
+    ESP_LOGV(TAG, "Answer %02X with id %u matches no open request", raw[1], message.id);
+  }
+#endif
+}
+
+#ifdef DUCO_DEVICE_COUNT
+void Duco::update_warning_() {
+  for (const auto &pending : this->pending_) {
+    if (pending.missed) {
+      this->status_set_warning(LOG_STR("No answer from the box"));
+      return;
+    }
+  }
+  this->status_clear_warning();
+}
+#endif
+
+void Duco::dump_config() {
+  ESP_LOGCONFIG(TAG,
+                "Duco:\n"
+                "  CRC Disabled: %s",
+                YESNO(this->disable_crc_));
+}
+
+uint8_t Duco::next_id_() {
+  do {
+    this->last_id_++;
+  } while (this->last_id_ == HEADER_START || this->last_id_ == HEADER_END);
+  return this->last_id_;
+}
+
+void Duco::send(DucoDevice *device, uint8_t function, std::initializer_list<uint8_t> data) {
+  if (data.size() > MAX_REQUEST_DATA) {
+    ESP_LOGE(TAG, "Request of %u bytes is too long", static_cast<unsigned>(data.size()));
+    return;
+  }
+  // Not byte stuffed, as in the author's original and no capture shows a request with 0xAA. An 0xAA followed by any
+  // byte but 0x01 or 0x55 reads the same with or without unstuffing on the box, so only those rare pairs are
+  // unverified.
+  const size_t size = data.size();
+  const uint8_t id = this->next_id_();
+  uint8_t frame[5 + MAX_REQUEST_DATA + 2] = {HEADER_START, HEADER_END, static_cast<uint8_t>(size + 2), function, id};
+  std::copy_n(data.begin(), size, frame + 5);
+  const uint16_t crc = crc16(frame + 2, size + 3);
+  frame[size + 5] = crc & 0xFF;
+  frame[size + 6] = crc >> 8;
+  this->write_array(frame, size + 7);
+  this->flush();
+
+#ifdef DUCO_DEVICE_COUNT
+  for (auto &pending : this->pending_) {
+    if (pending.device == device) {
+      pending.missed = pending.function != 0;
+      if (pending.missed) {
+        ESP_LOGV(TAG, "No answer to request %02X with id %u", pending.function, pending.id);
+        this->update_warning_();
+      }
+      pending.id = id;
+      pending.function = function;
+      break;
+    }
+  }
+#endif
+
+  ESP_LOGV_HEX(TAG, frame + 2, size + 5, sizeof(frame), "Sent %s");
+}
+
+static const LogString *node_type_name(uint8_t type) {
+  switch (type) {
+    case 8:
+      return LOG_STR("UCBAT");
+    case 9:
+      return LOG_STR("UC");
+    case 10:
+      return LOG_STR("UCRH");
+    case 12:
+      return LOG_STR("UCCO2");
+    case 13:
+      return LOG_STR("VLV");
+    case 17:
+      return LOG_STR("BOX");
+    case 18:
+      return LOG_STR("SWITCH");
+    default:
+      return LOG_STR("UNKNOWN");
+  }
+}
+
+void DucoDiscovery::setup() {
+  // Give the box time to start before walking its node addresses
+  this->set_timeout(DISCOVERY_START_ID, DISCOVERY_START_MS, [this]() {
+    this->set_interval(DISCOVERY_STEP_ID, DISCOVERY_STEP_MS, [this]() { this->update(); });
+  });
+}
+
+void DucoDiscovery::update() {
+  if (this->attempts_ == DISCOVERY_MAX_ATTEMPTS) {
+    ESP_LOGV(TAG, "No answer for node %u", this->next_node_);
+    this->next_node_++;
+    this->attempts_ = 0;
+  }
+  if (this->next_node_ >= NODE_COUNT) {
+    this->cancel_interval(DISCOVERY_STEP_ID);
+    this->parent_->close_request(this);
+    return;
+  }
+  // Without an answer by the next step the same node is asked again; a retry is not a missed answer
+  if (this->attempts_ > 0)
+    this->parent_->close_request(this);
+  ESP_LOGV(TAG, "Discovering node %u", this->next_node_);
+  this->attempts_++;
+  this->parent_->send(this, FUNCTION_NODE, {0x01, this->next_node_});
+}
+
+void DucoDiscovery::receive_response(const DucoMessage &message) {
+  // Only the latest attempt is open, so a late answer to an earlier one never arrives here
+  if (message.size >= 1 && this->next_node_ < NODE_COUNT) {
+    if (message.data[0] != 0) {
+      ESP_LOGV(TAG, "Found node %u: type %u", this->next_node_, message.data[0]);
+    }
+    this->node_types_[this->next_node_++] = message.data[0];
+    this->attempts_ = 0;
+  }
+}
+
+void DucoDiscovery::dump_config() {
+  ESP_LOGCONFIG(TAG, "Discovered nodes:");
+  for (uint8_t node = 0; node < NODE_COUNT; node++) {
+    const uint8_t type = this->node_types_[node];
+    if (type != 0) {
+      ESP_LOGCONFIG(TAG, "  Node %u: type %u (%s)", node, type, LOG_STR_ARG(node_type_name(type)));
+    }
+  }
+  if (this->next_node_ < NODE_COUNT) {
+    ESP_LOGCONFIG(TAG, "  Still discovering, at node %u", this->next_node_);
+  }
+}
+
+#ifdef USE_TIME
+void DucoTime::update() {
+  const ESPTime now = this->clock_->now();
+  if (!now.is_valid()) {
+    ESP_LOGV(TAG, "Time is not valid yet");
+    return;
+  }
+  const uint32_t ts = now.timestamp;
+  this->parent_->send(nullptr, FUNCTION_PARAMETER,
+                      {0x05, static_cast<uint8_t>(ts), static_cast<uint8_t>(ts >> 8), static_cast<uint8_t>(ts >> 16),
+                       static_cast<uint8_t>(ts >> 24), 0x00, 0x00, 0x00, 0x00});
+}
+#endif
+
+}  // namespace esphome::duco

esphome/components/duco/duco.h

@@ -0,0 +1,113 @@
+#pragma once
+
+#include <array>
+#include <initializer_list>
+
+#include "esphome/components/uart/uart.h"
+#include "esphome/core/component.h"
+#include "esphome/core/helpers.h"
+
+#ifdef USE_TIME
+#include "esphome/components/time/real_time_clock.h"
+#endif
+
+namespace esphome::duco {
+
+// Function codes of the requests; the box answers a request with function + 2
+static constexpr uint8_t FUNCTION_NODE = 0x0c;       // discovery, status and mode of a node
+static constexpr uint8_t FUNCTION_NODE_DATA = 0x10;  // a block of a node's data (sensors, serial number)
+static constexpr uint8_t FUNCTION_PARAMETER = 0x24;  // read or write a box parameter, set the clock
+
+/// A received message; data points into the receive buffer and is valid only during the callback.
+struct DucoMessage {
+  uint8_t id;
+  const uint8_t *data;
+  uint8_t size;
+};
+
+class DucoDevice;
+
+/// The open request of one device: the answer to it is function + 2 with the same message id.
+struct DucoPendingRequest {
+  DucoDevice *device;
+  uint8_t id;
+  uint8_t function;  // 0 while nothing is open
+  bool missed;       // the request before this one got no answer; sits in padding
+};
+
+class Duco : public uart::UARTDevice, public Component {
+ public:
+  void loop() override;
+  void dump_config() override;
+
+  void set_disable_crc(bool disable_crc) { this->disable_crc_ = disable_crc; }
+
+#ifdef DUCO_DEVICE_COUNT
+  void register_device(DucoDevice *device) { this->pending_.push_back({device, 0, 0, false}); }
+#endif
+
+  /// Forget device's open request, for a device that will not send again.
+  void close_request(DucoDevice *device);
+
+  /// Send a request; its answer goes to device, or nowhere if nullptr. A device's new request replaces its
+  /// open one, so an answer is never lost to another device's traffic.
+  void send(DucoDevice *device, uint8_t function, std::initializer_list<uint8_t> data);
+
+ protected:
+  // The longest answer to a request sent here is 25 bytes (node status), the longest request 9
+  static constexpr size_t MAX_FRAME_SIZE = 32;
+  static constexpr size_t MAX_REQUEST_DATA = 9;
+
+  bool parse_byte_(uint8_t byte);
+  void reset_frame_();
+#ifdef DUCO_DEVICE_COUNT
+  void update_warning_();  // warn while any device's previous request went unanswered
+#endif
+  void finalize_message_();
+  uint8_t next_id_();
+
+#ifdef DUCO_DEVICE_COUNT
+  StaticVector<DucoPendingRequest, DUCO_DEVICE_COUNT> pending_;
+#endif
+  std::array<uint8_t, MAX_FRAME_SIZE> rx_buffer_{};
+  uint32_t last_byte_{0};
+  uint8_t rx_size_{0};
+  uint8_t last_id_{10};
+  bool escaped_{false};  // the last 0xAA was followed by a stuffing byte, so it starts no header
+  bool disable_crc_{false};
+};
+
+/// Every entity polls the box; deriving from PollingComponent shares its vtable.
+class DucoDevice : public PollingComponent, public Parented<Duco> {
+ public:
+  virtual void receive_response(const DucoMessage &message) = 0;
+};
+
+/// Walks the node addresses once after boot; the nodes found are listed in the config dump.
+class DucoDiscovery : public DucoDevice {
+ public:
+  void setup() override;
+  void dump_config() override;
+  void update() override;  // one discovery step, run by the step interval
+  void receive_response(const DucoMessage &message) override;
+
+ protected:
+  static constexpr uint8_t NODE_COUNT = 0x45;
+
+  std::array<uint8_t, NODE_COUNT> node_types_{};  // 0 when no node answered at that address
+  uint8_t next_node_{0};
+  uint8_t attempts_{0};
+};
+
+#ifdef USE_TIME
+class DucoTime : public PollingComponent, public Parented<Duco> {
+ public:
+  explicit DucoTime(time::RealTimeClock *clock) : clock_(clock) {}
+  void update() override;
+
+ protected:
+  time::RealTimeClock *clock_;
+};
+#endif
+
+}  // namespace esphome::duco

esphome/components/duco/number/__init__.py

@@ -0,0 +1,34 @@
+from esphome.components import number
+import esphome.config_validation as cv
+from esphome.const import DEVICE_CLASS_TEMPERATURE, UNIT_CELSIUS
+from esphome.types import ConfigType
+
+from .. import (
+    CONF_DUCO_ID,
+    DUCO_COMPONENT_SCHEMA,
+    DucoDevice,
+    duco_ns,
+    register_duco_device,
+)
+
+DEPENDENCIES = ["duco"]
+CODEOWNERS = ["@kokx"]
+
+DucoComfortTemperature = duco_ns.class_(
+    "DucoComfortTemperature", DucoDevice, number.Number
+)
+
+CONFIG_SCHEMA = (
+    number.number_schema(
+        DucoComfortTemperature,
+        unit_of_measurement=UNIT_CELSIUS,
+        device_class=DEVICE_CLASS_TEMPERATURE,
+    )
+    .extend(DUCO_COMPONENT_SCHEMA)
+    .extend(cv.polling_component_schema("60s"))
+)
+
+
+async def to_code(config: ConfigType) -> None:
+    var = await number.new_number(config, min_value=10.0, max_value=25.5, step=0.1)
+    await register_duco_device(var, config, config[CONF_DUCO_ID])

esphome/components/duco/number/number.cpp

@@ -0,0 +1,26 @@
+#include "number.h"
+
+#include <cmath>
+
+namespace esphome::duco {
+
+static constexpr uint8_t PARAMETER_COMFORT_TEMPERATURE = 0x12;
+static constexpr uint8_t GROUP_COMFORT_TEMPERATURE = 0x0a;
+
+void DucoComfortTemperature::update() {
+  this->parent_->send(this, FUNCTION_PARAMETER, {0x00, PARAMETER_COMFORT_TEMPERATURE, GROUP_COMFORT_TEMPERATURE});
+}
+
+void DucoComfortTemperature::receive_response(const DucoMessage &message) {
+  // Reads and writes get the same answer: one byte in tenths of a degree, below 10.0 is invalid
+  if (message.size >= 4 && message.data[3] >= 100)
+    this->publish_state(message.data[3] / 10.0f);
+}
+
+void DucoComfortTemperature::control(float value) {
+  const auto tenths = static_cast<uint8_t>(lroundf(value * 10.0f));
+  this->parent_->send(this, FUNCTION_PARAMETER,
+                      {0x01, PARAMETER_COMFORT_TEMPERATURE, GROUP_COMFORT_TEMPERATURE, tenths, 0x00, 0x00, 0x00});
+}
+
+}  // namespace esphome::duco

esphome/components/duco/number/number.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "esphome/components/number/number.h"
+
+#include "../duco.h"
+
+namespace esphome::duco {
+
+class DucoComfortTemperature : public DucoDevice, public number::Number {
+ public:
+  void update() override;
+  void receive_response(const DucoMessage &message) override;
+
+ protected:
+  void control(float value) override;
+};
+
+}  // namespace esphome::duco

esphome/components/duco/select/__init__.py

@@ -0,0 +1,45 @@
+from esphome.components import select
+import esphome.config_validation as cv
+from esphome.types import ConfigType
+
+from .. import (
+    CONF_DUCO_ID,
+    DUCO_COMPONENT_SCHEMA,
+    DucoDevice,
+    duco_ns,
+    register_duco_device,
+)
+
+DEPENDENCIES = ["duco"]
+CODEOWNERS = ["@kokx"]
+
+# Same order as MODE_CODES in select.cpp
+DUCO_MODE_OPTIONS = [
+    "AUTO",
+    "MAN1",
+    "MAN2",
+    "MAN3",
+    "EMPT",
+    "CNT1",
+    "CNT2",
+    "CNT3",
+    "MAN1x2",
+    "MAN2x2",
+    "MAN3x2",
+    "MAN1x3",
+    "MAN2x3",
+    "MAN3x3",
+]
+
+DucoSelect = duco_ns.class_("DucoSelect", DucoDevice, select.Select)
+
+CONFIG_SCHEMA = (
+    select.select_schema(DucoSelect)
+    .extend(cv.polling_component_schema("3s"))
+    .extend(DUCO_COMPONENT_SCHEMA)
+)
+
+
+async def to_code(config: ConfigType) -> None:
+    var = await select.new_select(config, options=DUCO_MODE_OPTIONS)
+    await register_duco_device(var, config, config[CONF_DUCO_ID])

esphome/components/duco/select/select.cpp

@@ -0,0 +1,47 @@
+#include "select.h"
+
+#include "esphome/core/hal.h"
+#include "esphome/core/log.h"
+
+namespace esphome::duco {
+
+ESPHOME_LOG_TAG(TAG, "duco.select");
+
+// Box code of each option, in the order of DUCO_MODE_OPTIONS in __init__.py
+static constexpr uint8_t MODE_CODES[] PROGMEM = {
+    0x00,  // AUTO
+    0x04,  // MAN1
+    0x05,  // MAN2
+    0x06,  // MAN3
+    0x07,  // EMPT
+    0x08,  // CNT1
+    0x09,  // CNT2
+    0x0a,  // CNT3
+    0x84,  // MAN1x2
+    0x85,  // MAN2x2
+    0x86,  // MAN3x2
+    0xc4,  // MAN1x3
+    0xc5,  // MAN2x3
+    0xc6,  // MAN3x3
+};
+
+void DucoSelect::update() { this->parent_->send(this, FUNCTION_NODE, {0x02, 0x01}); }
+
+void DucoSelect::receive_response(const DucoMessage &message) {
+  if (message.size < 1)
+    return;
+  for (size_t i = 0; i < sizeof(MODE_CODES); i++) {
+    if (progmem_read_byte(&MODE_CODES[i]) == message.data[0]) {
+      this->publish_state(i);
+      return;
+    }
+  }
+  ESP_LOGV(TAG, "Unknown mode %02X", message.data[0]);
+}
+
+void DucoSelect::control(size_t index) {
+  // The next update reads the new mode back
+  this->parent_->send(nullptr, FUNCTION_NODE, {0x04, 0x01, progmem_read_byte(&MODE_CODES[index])});
+}
+
+}  // namespace esphome::duco

esphome/components/duco/select/select.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "esphome/components/select/select.h"
+
+#include "../duco.h"
+
+namespace esphome::duco {
+
+class DucoSelect : public DucoDevice, public select::Select {
+ public:
+  void update() override;
+  void receive_response(const DucoMessage &message) override;
+
+ protected:
+  void control(size_t index) override;
+};
+
+}  // namespace esphome::duco

esphome/components/duco/sensor/__init__.py

@@ -0,0 +1,156 @@
+from esphome.components import sensor
+import esphome.config_validation as cv
+from esphome.const import (
+    CONF_ADDRESS,
+    CONF_CO2,
+    CONF_HUMIDITY,
+    CONF_TEMPERATURE,
+    DEVICE_CLASS_CARBON_DIOXIDE,
+    DEVICE_CLASS_DURATION,
+    DEVICE_CLASS_HUMIDITY,
+    DEVICE_CLASS_TEMPERATURE,
+    STATE_CLASS_MEASUREMENT,
+    UNIT_CELSIUS,
+    UNIT_PARTS_PER_MILLION,
+    UNIT_PERCENT,
+    UNIT_SECOND,
+)
+from esphome.types import ConfigType
+
+from .. import (
+    CONF_DUCO_ID,
+    DUCO_COMPONENT_SCHEMA,
+    DucoDevice,
+    duco_ns,
+    register_duco_device,
+)
+
+DEPENDENCIES = ["duco"]
+CODEOWNERS = ["@kokx"]
+
+UNIT_DAYS = "d"
+
+CONF_BYPASS = "bypass"
+CONF_FILTER_REMAINING = "filter_remaining"
+CONF_FLOW_LEVEL = "flow_level"
+CONF_TEMPERATURE_EHA = "temperature_eha"
+CONF_TEMPERATURE_ETA = "temperature_eta"
+CONF_TEMPERATURE_ODA = "temperature_oda"
+CONF_TEMPERATURE_SUP = "temperature_sup"
+CONF_TIME_REMAINING = "time_remaining"
+
+DucoSensor = duco_ns.class_("DucoSensor", DucoDevice, sensor.Sensor)
+DucoReading = duco_ns.enum("DucoReading", is_class=True)
+
+BOX_NODE = 1
+
+
+def _schema(update_interval: str = "60s", **kwargs) -> cv.Schema:
+    return sensor.sensor_schema(
+        DucoSensor, state_class=STATE_CLASS_MEASUREMENT, **kwargs
+    ).extend(cv.polling_component_schema(update_interval))
+
+
+def _node_schema(**kwargs) -> cv.All:
+    """A list of sensors, one per node address."""
+    return cv.ensure_list(
+        _schema(**kwargs).extend({cv.Required(CONF_ADDRESS): cv.int_range(0, 68)})
+    )
+
+
+_TEMPERATURE = {
+    "unit_of_measurement": UNIT_CELSIUS,
+    "accuracy_decimals": 1,
+    "device_class": DEVICE_CLASS_TEMPERATURE,
+}
+
+# key: (what is read, request argument or None for the node address, schema)
+SENSORS = {
+    CONF_CO2: (
+        DucoReading.DUCO_READING_CO2,
+        None,
+        _node_schema(
+            unit_of_measurement=UNIT_PARTS_PER_MILLION,
+            accuracy_decimals=0,
+            device_class=DEVICE_CLASS_CARBON_DIOXIDE,
+        ),
+    ),
+    CONF_TEMPERATURE: (
+        DucoReading.DUCO_READING_NODE_TEMPERATURE,
+        None,
+        _node_schema(**_TEMPERATURE),
+    ),
+    CONF_HUMIDITY: (
+        DucoReading.DUCO_READING_HUMIDITY,
+        None,
+        _node_schema(
+            unit_of_measurement=UNIT_PERCENT,
+            accuracy_decimals=1,
+            device_class=DEVICE_CLASS_HUMIDITY,
+        ),
+    ),
+    CONF_FILTER_REMAINING: (
+        DucoReading.DUCO_READING_FILTER_REMAINING,
+        0x30,
+        _schema(
+            "1200s",
+            unit_of_measurement=UNIT_DAYS,
+            accuracy_decimals=0,
+            device_class=DEVICE_CLASS_DURATION,
+        ),
+    ),
+    CONF_FLOW_LEVEL: (
+        DucoReading.DUCO_READING_FLOW_LEVEL,
+        BOX_NODE,
+        _schema(unit_of_measurement=UNIT_PERCENT, accuracy_decimals=0),
+    ),
+    CONF_TIME_REMAINING: (
+        DucoReading.DUCO_READING_TIME_REMAINING,
+        BOX_NODE,
+        _schema(
+            unit_of_measurement=UNIT_SECOND,
+            accuracy_decimals=0,
+            device_class=DEVICE_CLASS_DURATION,
+        ),
+    ),
+    CONF_TEMPERATURE_ODA: (
+        DucoReading.DUCO_READING_BOX_TEMPERATURE,
+        0x00,
+        _schema(**_TEMPERATURE),
+    ),
+    CONF_TEMPERATURE_SUP: (
+        DucoReading.DUCO_READING_BOX_TEMPERATURE,
+        0x01,
+        _schema(**_TEMPERATURE),
+    ),
+    CONF_TEMPERATURE_ETA: (
+        DucoReading.DUCO_READING_BOX_TEMPERATURE,
+        0x02,
+        _schema(**_TEMPERATURE),
+    ),
+    CONF_TEMPERATURE_EHA: (
+        DucoReading.DUCO_READING_BOX_TEMPERATURE,
+        0x03,
+        _schema(**_TEMPERATURE),
+    ),
+    CONF_BYPASS: (
+        DucoReading.DUCO_READING_BYPASS,
+        0x10,
+        _schema(unit_of_measurement=UNIT_PERCENT, accuracy_decimals=0),
+    ),
+}
+
+CONFIG_SCHEMA = DUCO_COMPONENT_SCHEMA.extend(
+    {cv.Optional(key): schema for key, (_, _, schema) in SENSORS.items()}
+)
+
+
+async def to_code(config: ConfigType) -> None:
+    for key, (reading, argument, _) in SENSORS.items():
+        if (confs := config.get(key)) is None:
+            continue
+        for conf in confs if isinstance(confs, list) else [confs]:
+            var = await sensor.new_sensor(
+                conf, reading, conf.get(CONF_ADDRESS, argument)
+            )
+            await register_duco_device(var, conf, config[CONF_DUCO_ID])

esphome/components/duco/sensor/sensor.cpp

@@ -0,0 +1,78 @@
+#include "sensor.h"
+
+#include "esphome/core/hal.h"
+#include "esphome/core/log.h"
+
+namespace esphome::duco {
+
+ESPHOME_LOG_TAG(TAG, "duco.sensor");
+
+enum class DucoValueFormat : uint8_t {
+  DUCO_VALUE_FORMAT_UINT8,
+  DUCO_VALUE_FORMAT_UINT16,
+  DUCO_VALUE_FORMAT_INT16,
+};
+
+/// A little endian field at offset in the answer. Values outside [minimum, maximum] are dropped;
+/// the box reports those for sensors that are missing or still starting.
+struct ReadingLayout {
+  uint8_t function;
+  uint8_t offset;
+  DucoValueFormat format;
+  uint8_t divisor;
+  int16_t minimum;
+  uint16_t maximum;
+};
+
+// Indexed by DucoReading
+static constexpr ReadingLayout READINGS[] PROGMEM = {
+    {FUNCTION_NODE_DATA, 4, DucoValueFormat::DUCO_VALUE_FORMAT_UINT16, 1, 300, 10000},  // CO2
+    {FUNCTION_NODE_DATA, 2, DucoValueFormat::DUCO_VALUE_FORMAT_UINT16, 10, 0, 1000},    // node temperature
+    {FUNCTION_NODE_DATA, 6, DucoValueFormat::DUCO_VALUE_FORMAT_UINT16, 100, 0, 10000},  // humidity
+    {FUNCTION_PARAMETER, 3, DucoValueFormat::DUCO_VALUE_FORMAT_UINT8, 1, 0, 255},       // filter remaining
+    {FUNCTION_NODE, 2, DucoValueFormat::DUCO_VALUE_FORMAT_UINT8, 1, 0, 255},            // flow level
+    {FUNCTION_NODE, 12, DucoValueFormat::DUCO_VALUE_FORMAT_UINT16, 1, 0, 65535},        // time remaining
+    {FUNCTION_PARAMETER, 3, DucoValueFormat::DUCO_VALUE_FORMAT_INT16, 10, -999, 1000},  // box temperature
+    {FUNCTION_PARAMETER, 3, DucoValueFormat::DUCO_VALUE_FORMAT_UINT8, 1, 0, 100},       // bypass
+};
+
+static ReadingLayout layout_of(DucoReading reading) {
+  ReadingLayout layout;
+  progmem_memcpy(&layout, &READINGS[static_cast<uint8_t>(reading)], sizeof(layout));
+  return layout;
+}
+
+void DucoSensor::update() {
+  switch (layout_of(this->reading_).function) {
+    case FUNCTION_NODE_DATA:
+      this->parent_->send(this, FUNCTION_NODE_DATA, {0x01, this->argument_, 0x00, 0x49, 0x04});
+      break;
+    case FUNCTION_PARAMETER:
+      this->parent_->send(this, FUNCTION_PARAMETER, {0x00, this->argument_, 0x09});
+      break;
+    case FUNCTION_NODE:
+      this->parent_->send(this, FUNCTION_NODE, {0x02, this->argument_});
+      break;
+  }
+}
+
+void DucoSensor::receive_response(const DucoMessage &message) {
+  const ReadingLayout layout = layout_of(this->reading_);
+  const bool wide = layout.format != DucoValueFormat::DUCO_VALUE_FORMAT_UINT8;
+  if (message.size < layout.offset + (wide ? 2 : 1)) {
+    ESP_LOGV(TAG, "Answer of %u bytes is too short", message.size);
+    return;
+  }
+
+  const uint8_t *field = message.data + layout.offset;
+  int32_t value = field[0];
+  if (layout.format == DucoValueFormat::DUCO_VALUE_FORMAT_UINT16) {
+    value = encode_value_le<uint16_t>(field);
+  } else if (layout.format == DucoValueFormat::DUCO_VALUE_FORMAT_INT16) {
+    value = encode_value_le<int16_t>(field);
+  }
+  if (value >= layout.minimum && value <= layout.maximum)
+    this->publish_state(static_cast<float>(value) / layout.divisor);
+}
+
+}  // namespace esphome::duco

esphome/components/duco/sensor/sensor.h

@@ -0,0 +1,34 @@
+#pragma once
+
+#include "esphome/components/sensor/sensor.h"
+
+#include "../duco.h"
+
+namespace esphome::duco {
+
+/// What a sensor reads; the request and where the value is in the answer are in READINGS in sensor.cpp.
+enum class DucoReading : uint8_t {
+  DUCO_READING_CO2,
+  DUCO_READING_NODE_TEMPERATURE,
+  DUCO_READING_HUMIDITY,
+  DUCO_READING_FILTER_REMAINING,
+  DUCO_READING_FLOW_LEVEL,
+  DUCO_READING_TIME_REMAINING,
+  DUCO_READING_BOX_TEMPERATURE,
+  DUCO_READING_BYPASS,
+};
+
+class DucoSensor : public DucoDevice, public sensor::Sensor {
+ public:
+  /// argument is the node address, or the parameter number for a box parameter.
+  DucoSensor(DucoReading reading, uint8_t argument) : reading_(reading), argument_(argument) {}
+
+  void update() override;
+  void receive_response(const DucoMessage &message) override;
+
+ protected:
+  DucoReading reading_;
+  uint8_t argument_;
+};
+
+}  // namespace esphome::duco

esphome/components/duco/text_sensor/__init__.py

@@ -0,0 +1,27 @@
+from esphome.components import text_sensor
+import esphome.config_validation as cv
+from esphome.types import ConfigType
+
+from .. import (
+    CONF_DUCO_ID,
+    DUCO_COMPONENT_SCHEMA,
+    DucoDevice,
+    duco_ns,
+    register_duco_device,
+)
+
+DEPENDENCIES = ["duco"]
+CODEOWNERS = ["@kokx"]
+
+DucoSerial = duco_ns.class_("DucoSerial", DucoDevice, text_sensor.TextSensor)
+
+CONFIG_SCHEMA = (
+    text_sensor.text_sensor_schema(DucoSerial)
+    .extend(cv.polling_component_schema("300s"))
+    .extend(DUCO_COMPONENT_SCHEMA)
+)
+
+
+async def to_code(config: ConfigType) -> None:
+    var = await text_sensor.new_text_sensor(config)
+    await register_duco_device(var, config, config[CONF_DUCO_ID])

esphome/components/duco/text_sensor/serial.cpp

@@ -0,0 +1,17 @@
+#include "serial.h"
+
+#include <cstring>
+
+namespace esphome::duco {
+
+void DucoSerial::update() { this->parent_->send(this, FUNCTION_NODE_DATA, {0x01, 0x01, 0x00, 0x1a, 0x10}); }
+
+void DucoSerial::receive_response(const DucoMessage &message) {
+  if (message.size > 2) {
+    // The serial number starts at byte 2 and is padded with zeros
+    const char *serial = reinterpret_cast<const char *>(message.data + 2);
+    this->publish_state(serial, strnlen(serial, message.size - 2));
+  }
+}
+
+}  // namespace esphome::duco

esphome/components/duco/text_sensor/serial.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include "esphome/components/text_sensor/text_sensor.h"
+
+#include "../duco.h"
+
+namespace esphome::duco {
+
+class DucoSerial : public DucoDevice, public text_sensor::TextSensor {
+ public:
+  void update() override;
+  void receive_response(const DucoMessage &message) override;
+};
+
+}  // namespace esphome::duco

esphome/components/emontx/emontx.cpp

@@ -126,7 +126,7 @@ void EmonTx::loop() {
 
   // Read all available data to prevent UART buffer overflow
   this->read_available([this](uint8_t received) {
-    size_t len;
+    size_t len = 0;
     char *line = this->line_reader_.feed(received, len);
     this->line_reader_.log_if_overflowed(TAG);
     if (line == nullptr || len == 0) {

esphome/components/epaper_spi/epaper_goodisplay_3c.cpp

@@ -0,0 +1,12 @@
+#include "epaper_goodisplay_3c.h"
+
+namespace esphome::epaper_spi {
+
+void EPaperGoodDisplay3C::power_on() {}
+
+void EPaperGoodDisplay3C::refresh_screen(bool partial) {
+  EPaperWeAct3C::refresh_screen(partial);
+  this->next_delay_ = REFRESH_START_MS;
+}
+
+}  // namespace esphome::epaper_spi

esphome/components/epaper_spi/epaper_goodisplay_3c.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include "epaper_weact_3c.h"
+
+namespace esphome::epaper_spi {
+
+/**
+ * Good Display 3-color e-paper displays (SSD1680 controller), e.g. GDEY029Z95.
+ *
+ * Driven as EPaperWeAct3C, except that there is no separate power-on: the full refresh (0xF7) powers the panel
+ * up itself. Busy then only goes high a little after the refresh starts, so the next state waits before
+ * checking it.
+ */
+class EPaperGoodDisplay3C : public EPaperWeAct3C {
+ public:
+  using EPaperWeAct3C::EPaperWeAct3C;
+
+ protected:
+  // Time from master activation (0x20) until busy can be relied on
+  static constexpr uint16_t REFRESH_START_MS = 50;
+
+  // With EPaperWeAct3C's power-on (0x22 0xF8) first, this panel's refresh ends almost at once and the image
+  // does not change.
+  void power_on() override;
+  void refresh_screen(bool partial) override;
+};
+
+}  // namespace esphome::epaper_spi

esphome/components/epaper_spi/epaper_spi.cpp

@@ -1,4 +1,5 @@
 #include "epaper_spi.h"
+#include <algorithm>
 #include <cinttypes>
 #include "esphome/core/application.h"
 #include "esphome/core/helpers.h"
@@ -37,6 +38,42 @@ bool EPaperBase::init_buffer_(size_t buffer_length) {
   return true;
 }
 
+bool EPaperBase::init_sent_frame_(size_t length) {
+  if (!this->is_using_partial_update_())
+    return false;
+  if (this->sent_.init(length))
+    return true;
+  ESP_LOGW(TAG, "No memory for the previous frame; partial updates will send the whole drawn area");
+  return false;
+}
+
+uint32_t EPaperBase::buffer_hash_() const {
+  uint32_t hash = FNV1_OFFSET_BASIS;
+  size_t index = 0;
+  while (index != this->buffer_.size()) {
+    size_t length;
+    const uint8_t *data = this->buffer_.get_span(index, length);
+    for (size_t i = 0; i != length; i++)
+      hash = fnv1a_hash_extend(hash, data[i]);
+    index += length;
+  }
+  return hash;
+}
+
+void EPaperBase::set_full_bounds_() {
+  this->x_low_ = 0;
+  this->y_low_ = 0;
+  this->x_high_ = this->width_;
+  this->y_high_ = this->height_;
+}
+
+void EPaperBase::reset_bounds_() {
+  this->x_low_ = this->width_;
+  this->x_high_ = 0;
+  this->y_low_ = this->height_;
+  this->y_high_ = 0;
+}
+
 void EPaperBase::setup_pins_() const {
   for (auto *pin : this->enable_pins_) {
     pin->setup();
@@ -233,17 +270,28 @@ void EPaperBase::process_state_() {
         // Refresh the whole panel even if nothing was drawn
         this->full_update_requested_ = false;
         this->update_count_ = 0;
-        this->x_low_ = 0;
-        this->y_low_ = 0;
-        this->x_high_ = this->width_;
-        this->y_high_ = this->height_;
+        this->set_full_bounds_();
       }
       if (this->x_high_ < this->x_low_ || this->y_high_ < this->y_low_) {
         this->set_state_(EPaperState::IDLE);
         return;
       }
+      if (this->is_using_partial_update_()) {
+        const uint32_t frame_hash = this->buffer_hash_();
+        if (this->update_count_ != 0 && this->shown_hash_valid_ && frame_hash == this->shown_hash_) {
+          ESP_LOGD(TAG, "Frame unchanged, refresh skipped");
+          this->reset_bounds_();
+          this->set_state_(EPaperState::IDLE);
+          return;
+        }
+        this->shown_hash_ = frame_hash;
+      }
+      this->drawn_since_hash_ = false;
+      // Valid again only once this frame is on the panel, so an abandoned update leaves nothing to match
+      this->shown_hash_valid_ = false;
       // A full update resets update_count_ to zero, so a non-zero count marks a partial one
       this->partial_ = this->update_count_ != 0;
+      this->sent_count_ = 0;
       this->set_state_(EPaperState::RESET);
       break;
     case EPaperState::INITIALISE:
@@ -256,10 +304,15 @@ void EPaperBase::process_state_() {
       if (!this->transfer_data()) {
         return;  // Not done yet, come back next loop
       }
-      this->x_low_ = this->width_;
-      this->x_high_ = 0;
-      this->y_low_ = this->height_;
-      this->y_high_ = 0;
+      if (this->sent_.is_valid() && this->sent_count_ == this->sent_.size())
+        this->sent_valid_ = true;
+      // A draw during the chunked push may not have reached the panel, so the next update sends the whole frame
+      this->sent_hash_intact_ = this->is_using_partial_update_() && !this->drawn_since_hash_;
+      if (this->drawn_since_hash_) {
+        this->set_full_bounds_();
+      } else {
+        this->reset_bounds_();
+      }
       this->set_state_(EPaperState::POWER_ON);
       break;
     case EPaperState::POWER_ON:
@@ -280,6 +333,7 @@ void EPaperBase::process_state_() {
       break;
     case EPaperState::DEEP_SLEEP:
       this->deep_sleep();
+      this->shown_hash_valid_ = this->sent_hash_intact_;
       this->status_clear_warning();
       this->set_state_(EPaperState::IDLE);
       ESP_LOGD(TAG, "Display update took %" PRIu32 " ms", millis() - this->update_start_time_);
@@ -365,6 +419,7 @@ bool EPaperBase::rotate_coordinates_(int &x, int &y) {
   this->x_high_ = clamp_at_least(this->x_high_, x + 1);
   this->y_low_ = clamp_at_most(this->y_low_, y);
   this->y_high_ = clamp_at_least(this->y_high_, y + 1);
+  this->drawn_since_hash_ = true;
   return true;
 }
 
@@ -486,6 +541,7 @@ void HOT EPaperBase::draw_rgb565_block_(uint8_t *buffer, int x_start, int y_star
   this->x_high_ = clamp_at_least(this->x_high_, x_high);
   this->y_low_ = clamp_at_most(this->y_low_, y_low);
   this->y_high_ = clamp_at_least(this->y_high_, y_high);
+  this->drawn_since_hash_ = true;
 }
 
 // Writes an RGB565 block of pixels, as LVGL sends them, straight into a 1 bit per pixel buffer that is one block (the

esphome/components/epaper_spi/epaper_spi.h

@@ -99,10 +99,7 @@ class EPaperBase : public Display,
 
     // We store 8 pixels per byte
     this->buffer_.fill(pixel_color);
-    this->x_high_ = this->width_;
-    this->y_high_ = this->height_;
-    this->x_low_ = 0;
-    this->y_low_ = 0;
+    this->mark_all_drawn_();
   }
 
   void clear() override {
@@ -139,6 +136,25 @@ class EPaperBase : public Display,
   void wait_for_idle_(bool should_wait);
   void abandon_update_();
   bool init_buffer_(size_t buffer_length);
+  // Allocates the copy of the previous frame; only drivers that diff against it (needs_previous_frame) call this
+  bool init_sent_frame_(size_t length);
+  void record_sent_(size_t index, const uint8_t *data, size_t length) {
+    if (this->sent_.is_valid()) {
+      this->sent_.write(index, data, length);
+      this->sent_count_ += length;
+    }
+  }
+  // Whether the driver reads the previous frame (sent_) for its differential refresh
+  virtual bool needs_previous_frame() const { return false; }
+  // FNV-1a hash of the current frame buffer, to detect an unchanged frame without a full copy
+  uint32_t buffer_hash_() const;
+  void reset_bounds_();
+  void set_full_bounds_();
+  // For a draw that writes the whole buffer without going through rotate_coordinates_()
+  void mark_all_drawn_() {
+    this->set_full_bounds_();
+    this->drawn_since_hash_ = true;
+  }
   void update_effective_transform_();
   bool rotate_coordinates_(int &x, int &y);
   void draw_rgb565_block_(uint8_t *buffer, int x_start, int y_start, int w, int h, const uint8_t *ptr, bool big_endian,
@@ -200,6 +216,13 @@ class EPaperBase : public Display,
   size_t buffer_length_;
   size_t current_data_index_{};  // used by data transfer to track progress
   split_buffer::SplitBuffer buffer_{};
+  split_buffer::SplitBuffer sent_{};  // the previous frame, kept only by drivers that diff against it
+  bool sent_valid_{};                 // sent_ holds a whole frame
+  size_t sent_count_{};               // bytes recorded into sent_ by the update in progress
+  uint32_t shown_hash_{};             // hash of the frame on the panel, to skip an unchanged update
+  bool shown_hash_valid_{};           // shown_hash_ holds the hash of a frame whose refresh completed
+  bool sent_hash_intact_{};           // the buffer was unchanged by the end of the push of shown_hash_
+  bool drawn_since_hash_{};           // something was drawn after shown_hash_ was taken
   GPIOPin *dc_pin_{};
   GPIOPin *busy_pin_{};
   GPIOPin *reset_pin_{};

esphome/components/epaper_spi/epaper_spi_4bpp.cpp

@@ -18,11 +18,7 @@ void EPaper4bpp::fill(Color color) {
   // We store 2 pixels per byte
   this->buffer_.fill(pixel_color + (pixel_color << 4));
 
-  // Whole buffer just changed; mark the entire canvas dirty.
-  this->x_low_ = 0;
-  this->y_low_ = 0;
-  this->x_high_ = this->width_;
-  this->y_high_ = this->height_;
+  this->mark_all_drawn_();
 }
 
 void EPaper4bpp::clear() {

esphome/components/epaper_spi/epaper_spi_inkplate2.cpp

@@ -71,10 +71,7 @@ void EPaperInkplate2::fill(Color color) {
   for (size_t i = half_buffer; i < this->buffer_length_; i++)
     this->buffer_[i] = red_byte;
 
-  this->x_low_ = 0;
-  this->y_low_ = 0;
-  this->x_high_ = this->width_;
-  this->y_high_ = this->height_;
+  this->mark_all_drawn_();
 }
 
 void EPaperInkplate2::clear() { this->fill(COLOR_ON); }

esphome/components/epaper_spi/epaper_spi_jd79660.cpp

@@ -30,6 +30,7 @@ void EPaperJD79660::fill(Color color) {
 
   // We store 4 pixels per byte
   this->buffer_.fill(pixel_color | (pixel_color << 2) | (pixel_color << 4) | (pixel_color << 6));
+  this->drawn_since_hash_ = true;
 }
 
 void HOT EPaperJD79660::draw_pixel_at(int x, int y, Color color) {

esphome/components/epaper_spi/epaper_spi_mono.cpp

@@ -7,6 +7,12 @@
 namespace esphome::epaper_spi {
 ESPHOME_LOG_TAG(TAG, "epaper_spi.mono");
 
+void EPaperMono::setup() {
+  EPaperBase::setup();
+  if (!this->is_failed() && this->needs_previous_frame())
+    this->init_sent_frame_(this->sent_frame_length());
+}
+
 void EPaperMono::refresh_screen(bool partial) {
   ESP_LOGV(TAG, "Refresh screen");
   this->cmd_data(0x22, {partial ? (uint8_t) 0xFF : (uint8_t) 0xF7});
@@ -66,7 +72,8 @@ bool HOT EPaperMono::transfer_data() {
   ESP_LOGV(TAG, "Writing %u bytes at line %zu at %ums", row_length, this->current_data_index_, (unsigned) millis());
   this->start_data_();
   while (this->current_data_index_ != this->y_high_) {
-    size_t data_idx = this->current_data_index_ * this->row_width_ + this->x_low_ / 8;
+    const size_t row_start = this->current_data_index_ * this->row_width_ + this->x_low_ / 8;
+    size_t data_idx = row_start;
     for (size_t i = 0; i != row_length; i++) {
       bytes_to_send[i] = this->send_red_ && !this->send_red_as_image_ ? 0 : this->buffer_[data_idx++];
     }

esphome/components/epaper_spi/epaper_spi_mono.h

@@ -12,6 +12,8 @@ class EPaperMono : public EPaperBase {
              size_t init_sequence_length, DisplayType display_type = DISPLAY_TYPE_BINARY, uint8_t bits_per_pixel = 1)
       : EPaperBase(name, width, height, init_sequence, init_sequence_length, display_type, bits_per_pixel) {}
 
+  void setup() override;
+
  protected:
   void refresh_screen(bool partial) override;
   void power_on() override {}
@@ -19,6 +21,8 @@ class EPaperMono : public EPaperBase {
   void deep_sleep() override;
   bool reset() override;
   virtual void set_window();
+  // Bytes in the comparison frame; the buffer's size unless a subclass sends the frame in another layout
+  virtual size_t sent_frame_length() const { return this->buffer_length_; }
   bool transfer_data() override;
   bool send_red_{true};
   bool software_reset_{true};  // send 0x12 after the hardware reset

esphome/components/epaper_spi/epaper_spi_ssd1677.cpp

@@ -6,21 +6,6 @@
 #include "esphome/core/log.h"
 
 namespace esphome::epaper_spi {
-ESPHOME_LOG_TAG(TAG, "epaper_spi.ssd1677");
-
-void EPaperSSD1677::setup() {
-  EPaperMono::setup();
-  if (!this->is_failed())
-    this->init_comparison_frame_();
-}
-
-void EPaperSSD1677::init_comparison_frame_() {
-  if (!this->is_using_partial_update_())
-    return;
-  if (!this->sent_.init(this->plane_row_length_() * this->height_)) {
-    ESP_LOGW(TAG, "No memory for the comparison frame; partial updates will degrade unchanged areas");
-  }
-}
 
 void EPaperSSD1677::plane_row(size_t y, uint8_t *out) {
   const size_t row_length = this->plane_row_length_();
@@ -82,7 +67,7 @@ bool HOT EPaperSSD1677::transfer_data() {
     }
     this->write_array(data, length);
     if (this->plane_ == 1)
-      this->sent_.write(this->current_data_index_, data, length);
+      this->record_sent_(this->current_data_index_, data, length);
     this->current_data_index_ += length;
     if (this->current_data_index_ != plane_length && millis() - start_time > MAX_TRANSFER_TIME) {
       // Let the main loop run and come back next loop

esphome/components/epaper_spi/epaper_spi_ssd1677.h

@@ -26,12 +26,12 @@ class EPaperSSD1677 : public EPaperMono {
                 size_t init_sequence_length, DisplayType display_type = DISPLAY_TYPE_BINARY, uint8_t bits_per_pixel = 1)
       : EPaperMono(name, width, height, init_sequence, init_sequence_length, display_type, bits_per_pixel) {}
 
-  void setup() override;
-
  protected:
-  // Allocates the comparison frame when partial updates are enabled. Separate from setup() so it
-  // can run without a bus.
-  void init_comparison_frame_();
+  // Reads the previous frame to copy it into the other RAM bank on a full refresh
+  bool needs_previous_frame() const override { return true; }
+  // Allocates the comparison frame as setup() would, for tests that run without a bus.
+  void init_comparison_frame_() { this->init_sent_frame_(this->sent_frame_length()); }
+  size_t sent_frame_length() const override { return this->plane_row_length_() * this->height_; }
   // Bytes in one row of a RAM plane: 8 pixels per byte, whatever the buffer holds.
   size_t plane_row_length_() const { return (this->width_ + 7) / 8; }
   // Row y of the frame as a RAM plane holds it, 1 bit per pixel with 1 = white.
@@ -39,8 +39,7 @@ class EPaperSSD1677 : public EPaperMono {
   bool reset() override;
   bool transfer_data() override;
 
-  split_buffer::SplitBuffer sent_{};  // the frame last sent to 0x24, i.e. what the panel shows
-  uint8_t plane_{0};                  // 0 while sending 0x26, 1 while sending 0x24
+  uint8_t plane_{0};  // 0 while sending 0x26, 1 while sending 0x24
 };
 
 }  // namespace esphome::epaper_spi

esphome/components/epaper_spi/epaper_spi_ssd1677_gray4.cpp

@@ -29,10 +29,7 @@ void EPaperSSD1677Gray4::fill(Color color) {
   }
   const uint8_t level = color_to_gray4(color);
   this->buffer_.fill((uint8_t) (level | (level << 2) | (level << 4) | (level << 6)));
-  this->x_low_ = 0;
-  this->y_low_ = 0;
-  this->x_high_ = this->width_;
-  this->y_high_ = this->height_;
+  this->mark_all_drawn_();
 }
 
 void HOT EPaperSSD1677Gray4::draw_pixel_at(int x, int y, Color color) {
@@ -83,14 +80,14 @@ bool HOT EPaperSSD1677Gray4::transfer_data() {
   this->start_data_();
   while (this->current_data_index_ != this->y_high_) {
     const size_t src_row = this->current_data_index_ * this->row_width_ + this->x_low_ / 4;
-    for (size_t i = 0; i != plane_row_length; i++) {
-      const uint8_t plane = plane_byte(this->buffer_[src_row + 2 * i], this->buffer_[src_row + 2 * i + 1], first_pass);
-      // The OTP grayscale waveform treats data as inverted relative to monochrome
-      bytes_to_send[i] = (uint8_t) ~plane;
-      // What the next partial update compares against: the high bits, as a black-and-white frame.
-      if (first_pass && this->sent_.is_valid())
-        this->sent_[this->current_data_index_ * plane_row_length + i] = plane;
-    }
+    for (size_t i = 0; i != plane_row_length; i++)
+      bytes_to_send[i] = plane_byte(this->buffer_[src_row + 2 * i], this->buffer_[src_row + 2 * i + 1], first_pass);
+    // What the next partial update compares against: the high bits, as a black-and-white frame.
+    if (first_pass)
+      this->record_sent_(this->current_data_index_ * plane_row_length, bytes_to_send, plane_row_length);
+    // The OTP grayscale waveform treats data as inverted relative to monochrome
+    for (size_t i = 0; i != plane_row_length; i++)
+      bytes_to_send[i] = (uint8_t) ~bytes_to_send[i];
     ++this->current_data_index_;
     this->write_array(bytes_to_send, plane_row_length);
     if (millis() - start_time > MAX_TRANSFER_TIME) {

esphome/components/epaper_spi/epaper_spi_ssd1681.cpp

@@ -1,10 +1,50 @@
 #include "epaper_spi_ssd1681.h"
 
+#include <algorithm>
+#include <cstring>
+
 #include "esphome/core/log.h"
 
 namespace esphome::epaper_spi {
 ESPHOME_LOG_TAG(TAG, "epaper_spi.ssd1681");
 
+void EPaperSSD1681::bounds_from_changes_() {
+  if (!this->sent_valid_ || this->sent_.size() != this->buffer_.size())
+    return;
+  bool changed = false;
+  uint16_t row_low = this->height_, row_high = 0, col_low = this->row_width_, col_high = 0;
+  for (uint16_t row = 0; row != this->height_; row++) {
+    const size_t base = row * this->row_width_;
+    const size_t end = base + this->row_width_;
+    size_t index = base;
+    while (index != end) {
+      size_t new_length, old_length;
+      const uint8_t *new_bytes = this->buffer_.get_span(index, new_length);
+      const uint8_t *old_bytes = this->sent_.get_span(index, old_length);
+      const size_t length = std::min({new_length, old_length, end - index});
+      if (std::memcmp(new_bytes, old_bytes, length) != 0) {
+        for (size_t i = 0; i != length; i++) {
+          if (new_bytes[i] == old_bytes[i])
+            continue;
+          const auto col = static_cast<uint16_t>(index + i - base);
+          changed = true;
+          row_low = std::min(row_low, row);
+          row_high = std::max<uint16_t>(row_high, row + 1);
+          col_low = std::min(col_low, col);
+          col_high = std::max<uint16_t>(col_high, col + 1);
+        }
+      }
+      index += length;
+    }
+  }
+  if (!changed)
+    return;
+  this->x_low_ = col_low * 8;
+  this->x_high_ = std::min<uint16_t>(col_high * 8, this->width_);
+  this->y_low_ = row_low;
+  this->y_high_ = row_high;
+}
+
 bool HOT EPaperSSD1681::transfer_data() {
   if (this->current_data_index_ == 0 && this->send_red_) {
     if (!this->partial_) {
@@ -15,6 +55,7 @@ bool HOT EPaperSSD1681::transfer_data() {
       this->y_high_ = this->height_;
     } else {
       // 0x26 already holds the image on the panel: the controller copies 0x24 into it after each refresh
+      this->bounds_from_changes_();
       this->set_window();
       this->send_red_ = false;
     }

esphome/components/epaper_spi/epaper_spi_ssd1681.h

@@ -16,6 +16,10 @@ class EPaperSSD1681 : public EPaperSSD1683 {
   }
 
  protected:
+  // Reads the previous frame to compute the changed window for a partial refresh
+  bool needs_previous_frame() const override { return true; }
+  // Shrinks the update bounds to the bytes that differ from the frame last sent
+  void bounds_from_changes_();
   bool transfer_data() override;
   void refresh_screen(bool partial) override;
 };

esphome/components/epaper_spi/epaper_spi_ssd1683.cpp

@@ -71,12 +71,15 @@ bool HOT EPaperSSD1683::transfer_data() {
   ESP_LOGV(TAG, "Writing %u bytes at line %zu at %ums", row_length, this->current_data_index_, (unsigned) millis());
   this->start_data_();
   while (this->current_data_index_ != this->y_high_) {
-    size_t data_idx = this->current_data_index_ * this->row_width_ + this->x_low_;
+    const size_t row_start = this->current_data_index_ * this->row_width_ + this->x_low_;
+    size_t data_idx = row_start;
     for (size_t i = 0; i != row_length; i++) {
       bytes_to_send[i] = this->buffer_[data_idx++];
     }
     ++this->current_data_index_;
     this->write_array(&bytes_to_send.front(), row_length);  // NOLINT
+    if (!this->send_red_)
+      this->record_sent_(row_start, &bytes_to_send.front(), row_length);
     if (millis() - start_time > MAX_TRANSFER_TIME) {
       // Let the main loop run and come back next loop
       this->disable();

esphome/components/epaper_spi/epaper_spi_t133a01.cpp

@@ -232,6 +232,7 @@ void EPaperT133A01::fill(Color color) {
   }
   auto pixel_color = color_to_index(color);
   this->buffer_.fill(pixel_color + (pixel_color << 4));
+  this->drawn_since_hash_ = true;
 }
 
 void EPaperT133A01::draw_pixel_at(int x, int y, Color color) {

esphome/components/epaper_spi/epaper_waveshare_bwr.cpp

@@ -1,4 +1,5 @@
 #include "epaper_waveshare_bwr.h"
+#include "esphome/core/helpers.h"
 
 #include <algorithm>
 
@@ -36,17 +37,9 @@ void EPaperWaveshareBWR::draw_pixel_at(int x, int y, Color color) {
 
   const auto bwr = color_to_bwr(color);
 
-  if (bwr == BwrState::BWR_BLACK) {
-    this->buffer_[pos] |= bit;
-  } else {
-    this->buffer_[pos] &= ~bit;
-  }
+  assign_bits(this->buffer_[pos], bit, bwr == BwrState::BWR_BLACK);
 
-  if (bwr == BwrState::BWR_RED) {
-    this->buffer_[red_offset + pos] |= bit;
-  } else {
-    this->buffer_[red_offset + pos] &= ~bit;
-  }
+  assign_bits(this->buffer_[red_offset + pos], bit, bwr == BwrState::BWR_RED);
 }
 
 void EPaperWaveshareBWR::fill(Color color) {

esphome/components/epaper_spi/models/weact_bwr.py

@@ -4,11 +4,17 @@ Supported models:
 - weact-2.13in-3c: 122x250 pixels (2.13" display)
 - weact-2.9in-3c: 128x296 pixels (2.9" display)
 - weact-4.2in-3c: 400x300 pixels (4.2" display)
+- goodisplay-gdey029z95-2.9: 128x296 pixels (Good Display GDEY029Z95 2.9" display)
 
 These displays use SSD1680 or SSD1683 controller and require a specific initialization
 sequence. The DRV_OUT_CTL command is calculated from the display height.
+The Good Display panel is driven as the WeAct ones, except that it must not get the
+separate power-on before the refresh, so it has its own driver class, EPaperGoodDisplay3C.
 """
 
+import esphome.config_validation as cv
+from esphome.const import CONF_BUSY_PIN, CONF_RESET_PIN
+
 from . import EpaperModel
 
 
@@ -17,8 +23,10 @@ class WeActBWR(EpaperModel):
 
     source_files = ("epaper_weact_3c.cpp",)
 
-    def __init__(self, name, **defaults):
-        super().__init__(name, "EPaperWeAct3C", **defaults)
+    def __init__(
+        self, name: str, class_name: str = "EPaperWeAct3C", **defaults: object
+    ) -> None:
+        super().__init__(name, class_name, **defaults)
 
     def get_init_sequence(self, config):
         """Generate initialization sequence for WeAct BWR displays.
@@ -75,3 +83,27 @@ weact_4p2in3c = WeActBWR(
     data_rate="10MHz",
     minimum_update_interval="10s",
 )
+
+
+class GoodDisplayBWR(WeActBWR):
+    """Good Display Black/White/Red displays using SSD1680 controller."""
+
+    source_files = ("epaper_weact_3c.cpp", "epaper_goodisplay_3c.cpp")
+
+    def __init__(self, name: str, **defaults: object) -> None:
+        super().__init__(name, "EPaperGoodDisplay3C", **defaults)
+
+    def option(self, name, fallback=cv.UNDEFINED) -> cv.Optional | cv.Required:
+        # Only a hardware reset wakes the panel from deep sleep, and refreshes are timed by busy
+        if name in (CONF_RESET_PIN, CONF_BUSY_PIN):
+            return cv.Required(name)
+        return super().option(name, fallback)
+
+
+# Model: Good Display GDEY029Z95 2.9" BWR - 128x296 pixels, SSD1680 controller
+GoodDisplayBWR(
+    "goodisplay-gdey029z95-2.9",
+    width=128,
+    height=296,
+    minimum_update_interval="10s",
+)

esphome/components/es8156/es8156.cpp

@@ -1,6 +1,7 @@
 #include "es8156.h"
 #include "es8156_const.h"
 #include "esphome/core/hal.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include <cinttypes>
 
@@ -100,11 +101,7 @@ bool ES8156::set_mute_state_(bool mute_state) {
 
   ESP_LOGV(TAG, "Read ES8156_REG13_DAC_MUTE: %u", reg13);
 
-  if (mute_state) {
-    reg13 |= BIT(1) | BIT(2);
-  } else {
-    reg13 &= ~(BIT(1) | BIT(2));
-  }
+  assign_bits(reg13, BIT(1) | BIT(2), mute_state);
 
   ESP_LOGV(TAG, "Setting ES8156_REG13_DAC_MUTE to %u (muted: %s)", reg13, YESNO(mute_state));
   return this->write_byte(ES8156_REG13_DAC_MUTE, reg13);

esphome/components/es8311/es8311.cpp

@@ -1,6 +1,7 @@
 #include "es8311.h"
 #include "es8311_const.h"
 #include "esphome/core/hal.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include <cinttypes>
 
@@ -154,11 +155,7 @@ bool ES8311::configure_clock_() {
   // Register 0x06
   uint8_t reg06;
   ES8311_ERROR_CHECK(this->read_byte(ES8311_REG06_CLK_MANAGER, &reg06));
-  if (this->sclk_inverted_) {
-    reg06 |= BIT(5);
-  } else {
-    reg06 &= ~BIT(5);
-  }
+  assign_bits(reg06, BIT(5), this->sclk_inverted_);
   reg06 &= 0xE0;
   if (coefficient->bclk_div < 19) {
     reg06 |= (coefficient->bclk_div - 1) << 0;
@@ -223,11 +220,7 @@ bool ES8311::set_mute_state_(bool mute_state) {
     return false;
   }
 
-  if (mute_state) {
-    reg31 |= BIT(6) | BIT(5);
-  } else {
-    reg31 &= ~(BIT(6) | BIT(5));
-  }
+  assign_bits(reg31, BIT(6) | BIT(5), mute_state);
 
   return this->write_byte(ES8311_REG31_DAC, reg31);
 }

esphome/components/es8388/es8388.cpp

@@ -2,6 +2,7 @@
 
 #include <cinttypes>
 #include "esphome/core/hal.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 namespace esphome::es8388 {
@@ -184,11 +185,7 @@ bool ES8388::set_mute_state_(bool mute_state) {
   // DAC settings that must be preserved. Previously muting overwrote the whole
   // register with 0x3C and unmuting never cleared the bit, so once muted the DAC
   // could not be unmuted again.
-  if (mute_state) {
-    value |= ES8388_DACCONTROL3_DAC_MUTE;
-  } else {
-    value &= ~ES8388_DACCONTROL3_DAC_MUTE;
-  }
+  assign_bits(value, ES8388_DACCONTROL3_DAC_MUTE, mute_state);
 
   ESP_LOGV(TAG, "Setting ES8388_DACCONTROL3 to 0x%02X (muted: %s)", value, YESNO(mute_state));
   return this->write_byte(ES8388_DACCONTROL3, value);

esphome/components/esp32/__init__.py

@@ -1303,8 +1303,8 @@ def _resolve_framework_version(value: ConfigType) -> cv.Version:
             raise cv.Invalid("Only Arduino 3.0+ is supported.")
         recommended = ARDUINO_FRAMEWORK_VERSION_LOOKUP["recommended"]
     else:
-        if version < cv.Version(5, 0, 0):
-            raise cv.Invalid("Only ESP-IDF 5.0+ is supported.")
+        if version < cv.Version(5, 1, 0):
+            raise cv.Invalid("Only ESP-IDF 5.1+ is supported.")
         recommended = ESP_IDF_FRAMEWORK_VERSION_LOOKUP["recommended"]
 
     if version != recommended:
@@ -2213,6 +2213,22 @@ def idf_version() -> cv.Version:
     return CORE.data[KEY_ESP32][KEY_IDF_VERSION]
 
 
+def require_idf_version(
+    minimum: cv.Version, feature: str = "This feature"
+) -> Callable[[Any], Any]:
+    """Validator for an option that needs the underlying ESP-IDF at ``minimum`` or newer."""
+
+    def validator(value: Any) -> Any:
+        cv.only_on_esp32(value)
+        if (version := idf_version()) < minimum:
+            raise cv.Invalid(
+                f"{feature} requires ESP-IDF {minimum} or newer, got {version}"
+            )
+        return value
+
+    return validator
+
+
 def require_fatfs() -> None:
     """Mark that FATFS support is required by a component.
 
@@ -2851,9 +2867,9 @@ async def _reconcile_network_sdkconfig() -> None:
     # Software coexistence: enable when requested (the schema only allows it
     # alongside WiFi). Disable only in the Ethernet-without-WiFi case.
     if net.software_coexistence:
-        set_idf_sdkconfig_default("CONFIG_SW_COEXIST_ENABLE", True)
+        set_idf_sdkconfig_default("CONFIG_ESP_COEX_SW_COEXIST_ENABLE", True)
     elif wifi_disabled:
-        set_idf_sdkconfig_default("CONFIG_SW_COEXIST_ENABLE", False)
+        set_idf_sdkconfig_default("CONFIG_ESP_COEX_SW_COEXIST_ENABLE", False)
 
     # SoftAP support: drop it when WiFi is used without AP mode (IDF only).
     if not is_arduino and net.wifi and not net.wifi_ap:
@@ -3031,10 +3047,9 @@ async def to_code(config):
     # assert(), HAL_ASSERT and ESP_ERROR_CHECK bake __FILE__ into rodata, and
     # IDF's noflash placement puts the flash driver's copies in DRAM. The
     # basename keeps the panic output useful at a fraction of the size.
-    # __FILE_NAME__ is a GCC 12 builtin; IDF 5.0 still ships GCC 11.2.
-    if idf_version() >= cv.Version(5, 1, 0):
-        cg.add_build_flag("-D__FILE__=__FILE_NAME__")
-        cg.add_build_flag("-Wno-builtin-macro-redefined")
+    # __FILE_NAME__ is a GCC 12 builtin, which every supported IDF ships.
+    cg.add_build_flag("-D__FILE__=__FILE_NAME__")
+    cg.add_build_flag("-Wno-builtin-macro-redefined")
     # Deferred so KEY_COMPONENTS is fully populated -- see the coroutine.
     CORE.add_job(_finalize_arduino_aware_flags)
     cg.add_define("ESPHOME_BOARD", config[CONF_BOARD])

esphome/components/esp32_ble/__init__.py

@@ -473,17 +473,11 @@ def final_validation(config: ConfigType) -> None:
 
     # Check if hosted bluetooth is being used
     if ESP32_HOSTED_DOMAIN in full_config:
-        from esphome.components.esp32_hosted import uses_esp_hosted_3x
-
         add_idf_sdkconfig_option("CONFIG_BT_CLASSIC_ENABLED", False)
         add_idf_sdkconfig_option("CONFIG_BT_BLE_ENABLED", True)
         add_idf_sdkconfig_option("CONFIG_BT_BLUEDROID_ENABLED", True)
         add_idf_sdkconfig_option("CONFIG_BT_CONTROLLER_DISABLED", True)
-        if uses_esp_hosted_3x():
-            add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_HOST_FEAT_BT", True)
-        else:
-            add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_ENABLE_BT_BLUEDROID", True)
-            add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_BLUEDROID_HCI_VHCI", True)
+        add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_HOST_FEAT_BT", True)
 
     # Check if BLE Client is needed (via esp32_ble_tracker or esp32_ble_client)
     has_ble_client = (

esphome/components/esp32_ble/ble.cpp

@@ -14,15 +14,10 @@
 #include <cinttypes>
 extern "C" {
 #include <esp_hosted.h>
-#ifndef CONFIG_ESP_HOSTED_HOST_FEAT_BT
-#include <esp_hosted_misc.h>
-#include <esp_hosted_bluedroid.h>
-#endif
 }
-#ifdef CONFIG_ESP_HOSTED_HOST_FEAT_BT
+#include <eh_host_bt.h>
 #include <esp_hosted_bt_host_stack.h>
 #endif
-#endif
 #include <esp_bt_device.h>
 #include <esp_bt_main.h>
 #include <esp_gap_ble_api.h>
@@ -246,44 +241,28 @@ bool ESP32BLE::ble_setup_() {
   }
   ESP_LOGD(TAG, "Co-processor firmware %" PRIu32 ".%" PRIu32 ".%" PRIu32, fw_ver.major1, fw_ver.minor1, fw_ver.patch1);
 
-#ifdef CONFIG_ESP_HOSTED_HOST_FEAT_BT
-  esp_hosted_bt_host_stack_cfg_t bt_cfg{};
-  bt_cfg.stack = ESP_HOSTED_BT_HOST_STACK_BLUEDROID;
-  bt_cfg.bring_up_controller = true;
-  bt_cfg.controller_ready_timeout_ms = EH_BT_CTRL_DEFAULT_READY_TIMEOUT_MS;
-  if (esp_hosted_bt_host_stack_setup(&bt_cfg) != ESP_OK) {
-    ESP_LOGE(TAG,
-             "BT controller bring-up failed; co-processor firmware %" PRIu32 ".%" PRIu32 ".%" PRIu32
-             " may lack BT support. Update it with the esp32_hosted update component; BLE disabled",
-             fw_ver.major1, fw_ver.minor1, fw_ver.patch1);
-    return false;
-  }
-#else
-  if (esp_hosted_bt_controller_init() != ESP_OK) {
+  // Not the library's bring-up: its retry loop can block for minutes on a silent co-processor
+  err = eh_host_bt_controller_init();
+  if (err != ESP_OK && err != ESP_ERR_INVALID_STATE) {
     ESP_LOGE(TAG,
              "BT controller init failed; co-processor firmware %" PRIu32 ".%" PRIu32 ".%" PRIu32
              " may lack BT support. Update it with the esp32_hosted update component; BLE disabled",
              fw_ver.major1, fw_ver.minor1, fw_ver.patch1);
     return false;
   }
-
-  if (esp_hosted_bt_controller_enable() != ESP_OK) {
-    ESP_LOGE(TAG,
-             "BT controller enable failed; co-processor firmware %" PRIu32 ".%" PRIu32 ".%" PRIu32
-             " may lack BT support. Update it with the esp32_hosted update component; BLE disabled",
-             fw_ver.major1, fw_ver.minor1, fw_ver.patch1);
+  err = eh_host_bt_controller_enable();
+  if (err != ESP_OK && err != ESP_ERR_INVALID_STATE) {
+    ESP_LOGE(TAG, "BT controller enable failed: %s; BLE disabled", esp_err_to_name(err));
     return false;
   }
 
-  hosted_hci_bluedroid_open();
-
-  esp_bluedroid_hci_driver_operations_t operations = {
-      .send = hosted_hci_bluedroid_send,
-      .check_send_available = hosted_hci_bluedroid_check_send_available,
-      .register_host_callback = hosted_hci_bluedroid_register_host_callback,
-  };
-  esp_bluedroid_attach_hci_driver(&operations);
-#endif
+  esp_hosted_bt_host_stack_cfg_t bt_cfg{};
+  bt_cfg.stack = ESP_HOSTED_BT_HOST_STACK_BLUEDROID;
+  bt_cfg.bring_up_controller = false;
+  if (esp_hosted_bt_host_stack_setup(&bt_cfg) != ESP_OK) {
+    ESP_LOGE(TAG, "BT host stack setup failed; BLE disabled");
+    return false;
+  }
 #endif
 
   err = esp_bluedroid_init();
@@ -440,23 +419,11 @@ bool ESP32BLE::ble_dismantle_() {
       return false;
     }
   }
-#elif defined(CONFIG_ESP_HOSTED_HOST_FEAT_BT)
+#else
   if (esp_hosted_bt_host_stack_teardown() != ESP_OK) {
     ESP_LOGE(TAG, "esp_hosted_bt_host_stack_teardown failed");
     return false;
   }
-#else
-  if (esp_hosted_bt_controller_disable() != ESP_OK) {
-    ESP_LOGE(TAG, "esp_hosted_bt_controller_disable failed");
-    return false;
-  }
-
-  if (esp_hosted_bt_controller_deinit(false) != ESP_OK) {
-    ESP_LOGE(TAG, "esp_hosted_bt_controller_deinit failed");
-    return false;
-  }
-
-  hosted_hci_bluedroid_close();
 #endif
   return true;
 }

esphome/components/esp32_hosted/__init__.py

@@ -1,6 +1,6 @@
+import logging
 import os
 from pathlib import Path
-import re
 
 from esphome import pins
 from esphome.components import esp32
@@ -8,33 +8,25 @@ from esphome.components.const import CONF_SLOT, CONF_USE_PSRAM
 import esphome.config_validation as cv
 from esphome.const import (
     CONF_CLK_PIN,
-    CONF_COMPONENTS,
     CONF_CS_PIN,
-    CONF_FRAMEWORK,
     CONF_FREQUENCY,
     CONF_MISO_PIN,
     CONF_MOSI_PIN,
-    CONF_NAME,
-    CONF_REF,
     CONF_RESET_PIN,
     CONF_TYPE,
     CONF_VARIANT,
-    KEY_ESP32,
 )
-from esphome.core import CORE
 from esphome.cpp_generator import add_define
-import esphome.final_validate as fv
 from esphome.types import ConfigType
 
+_LOGGER = logging.getLogger(__name__)
+
 CODEOWNERS = ["@swoboda1337"]
 DEPENDENCIES = ["esp32"]
 DOMAIN = "esp32_hosted"
 # esp32_ble raises the task watchdog around the remote BT controller bring-up
 AUTO_LOAD = ["watchdog"]
 
-# 3.x is opt-in via a pin under esp32.framework.components (needs ESP-IDF 5.5)
-ESP_HOSTED_COMPONENT = "espressif/esp_hosted"
-
 CONF_ACTIVE_HIGH = "active_high"
 CONF_BUS_WIDTH = "bus_width"
 CONF_CMD_PIN = "cmd_pin"
@@ -72,7 +64,7 @@ _MAX_CUSTOM_MSG_HANDLERS = 8
 BASE_SCHEMA = cv.Schema(
     {
         cv.Required(CONF_VARIANT): cv.one_of(*esp32.VARIANTS, upper=True),
-        cv.Required(CONF_ACTIVE_HIGH): cv.boolean,
+        cv.Optional(CONF_ACTIVE_HIGH): cv.boolean,
         cv.Required(CONF_RESET_PIN): pins.internal_gpio_output_pin_number,
         cv.Optional(CONF_USE_PSRAM, default=False): cv.boolean,
     }
@@ -83,7 +75,7 @@ SDIO_SCHEMA = BASE_SCHEMA.extend(
         cv.Required(CONF_CLK_PIN): pins.internal_gpio_output_pin_number,
         cv.Required(CONF_CMD_PIN): pins.internal_gpio_output_pin_number,
         cv.Required(CONF_D0_PIN): pins.internal_gpio_output_pin_number,
-        cv.Optional(CONF_D1_PIN): pins.internal_gpio_output_pin_number,
+        cv.Required(CONF_D1_PIN): pins.internal_gpio_output_pin_number,
         cv.Optional(CONF_D2_PIN): pins.internal_gpio_output_pin_number,
         cv.Optional(CONF_D3_PIN): pins.internal_gpio_output_pin_number,
         cv.Optional(CONF_BUS_WIDTH, default=4): cv.one_of(1, 4, int=True),
@@ -95,9 +87,26 @@ SDIO_SCHEMA = BASE_SCHEMA.extend(
 )
 
 
+def _validate_active_high(config: ConfigType) -> ConfigType:
+    # Remove before 2027.5.0
+    if (active_high := config.get(CONF_ACTIVE_HIGH)) is None:
+        return config
+    if not active_high:
+        raise cv.Invalid(
+            "esp_hosted always parks the reset line high with a low pulse, so "
+            "'active_high: false' is not supported.",
+            path=[CONF_ACTIVE_HIGH],
+        )
+    _LOGGER.warning(
+        "'active_high' is deprecated and ignored, remove it from esp32_hosted. "
+        "Removed in 2027.5.0"
+    )
+    return config
+
+
 def _validate_sdio(config: ConfigType) -> ConfigType:
     if config[CONF_BUS_WIDTH] == 4:
-        for pin in (CONF_D1_PIN, CONF_D2_PIN, CONF_D3_PIN):
+        for pin in (CONF_D2_PIN, CONF_D3_PIN):
             if pin not in config:
                 raise cv.Invalid(
                     f"{pin} is required when bus_width is 4",
@@ -150,121 +159,26 @@ def _validate_spi(config: ConfigType) -> ConfigType:
 
 CONFIG_SCHEMA = cv.typed_schema(
     {
-        "sdio": cv.All(SDIO_SCHEMA, _validate_sdio),
-        "spi": cv.All(SPI_SCHEMA, _validate_spi),
+        "sdio": cv.All(SDIO_SCHEMA, _validate_sdio, _validate_active_high),
+        "spi": cv.All(SPI_SCHEMA, _validate_spi, _validate_active_high),
     },
     default_type="sdio",
 )
 
 
-# Version specs that stay within one major (exact, ^, ~, ~=); other ranges are 3.x
-_PINNED_MAJOR = re.compile(r"^(?:==|\^|~=|~)?(\d+)(?:\.(?:\d+|\*))*$")
-
-
-def user_esp_hosted_major() -> int | None:
-    """Major version of a user-pinned esp_hosted, or None without a pin."""
-    try:
-        full_config = fv.full_config.get()
-    except LookupError:
-        full_config = CORE.config
-    esp32_config = full_config.get(KEY_ESP32) or {}
-    for component in esp32_config.get(CONF_FRAMEWORK, {}).get(CONF_COMPONENTS, []):
-        if component.get(CONF_NAME) != ESP_HOSTED_COMPONENT:
-            continue
-        ref = component.get(CONF_REF, "").strip()
-        if not ref:
-            return 2
-        if match := _PINNED_MAJOR.match(ref):
-            return int(match.group(1))
-        return 3
-    return None
-
-
-def uses_esp_hosted_3x() -> bool:
-    """Whether the user pinned esp_hosted 3.x."""
-    return (major := user_esp_hosted_major()) is not None and major >= 3
-
-
 def _final_validate(config: ConfigType) -> None:
-    # The esp_hosted releases compatible with older ESP-IDF versions crash at
-    # boot with a heap double free in the SDIO RX path (fixed in esp_hosted
-    # 2.11.0, which requires ESP-IDF 5.3), so reject them at validation time.
-    if (idf_ver := esp32.idf_version()) < cv.Version(5, 3, 0):
+    if (idf_ver := esp32.idf_version()) < cv.Version(5, 5, 0):
         raise cv.Invalid(
-            f"esp32_hosted requires ESP-IDF 5.3 or newer, got {idf_ver}. "
+            f"esp32_hosted requires ESP-IDF 5.5 or newer, got {idf_ver}. "
             "Remove the framework version from your configuration to use the "
-            "recommended version, or pin a version at or above 5.3."
-        )
-    if (major := user_esp_hosted_major()) is None or major < 3:
-        return
-    if idf_ver < cv.Version(5, 5, 0):
-        raise cv.Invalid(
-            f"esp_hosted 3.x requires ESP-IDF 5.5 or newer, got {idf_ver}. "
-            f"Remove the {ESP_HOSTED_COMPONENT} pin from esp32.framework."
-            "components to stay on the 2.x line, or use ESP-IDF 5.5 or newer."
-        )
-    if not config[CONF_ACTIVE_HIGH]:
-        raise cv.Invalid(
-            "esp_hosted 3.x always parks the reset line high with a low pulse, so "
-            "'active_high: false' cannot be expressed on it. Remove the "
-            f"{ESP_HOSTED_COMPONENT} pin from esp32.framework.components to stay "
-            "on the 2.x line."
-        )
-    if config[CONF_TYPE] == "sdio" and config[CONF_BUS_WIDTH] == 1:
-        raise cv.Invalid(
-            "esp_hosted 3.x cannot be built with a 1-bit SDIO bus "
-            "(espressif/esp-hosted-mcu#245). Remove the "
-            f"{ESP_HOSTED_COMPONENT} pin from esp32.framework.components to stay "
-            "on the 2.x line, or use a 4-bit bus."
+            "recommended version, or pin a version at or above 5.5."
         )
 
 
 FINAL_VALIDATE_SCHEMA = _final_validate
 
 
-def _configure_sdio_2x(config: ConfigType) -> None:
-    slot = config[CONF_SLOT]
-    esp32.add_idf_sdkconfig_option(
-        f"CONFIG_ESP_HOSTED_SDIO_SLOT_{slot}",
-        True,
-    )
-    if config[CONF_BUS_WIDTH] == 1:
-        esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_SDIO_1_BIT_BUS", True)
-    else:
-        esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_SDIO_4_BIT_BUS", True)
-    esp32.add_idf_sdkconfig_option(
-        f"CONFIG_ESP_HOSTED_PRIV_SDIO_PIN_CLK_SLOT_{slot}",
-        config[CONF_CLK_PIN],
-    )
-    esp32.add_idf_sdkconfig_option(
-        f"CONFIG_ESP_HOSTED_PRIV_SDIO_PIN_CMD_SLOT_{slot}",
-        config[CONF_CMD_PIN],
-    )
-    esp32.add_idf_sdkconfig_option(
-        f"CONFIG_ESP_HOSTED_PRIV_SDIO_PIN_D0_SLOT_{slot}",
-        config[CONF_D0_PIN],
-    )
-    if config[CONF_BUS_WIDTH] == 4:
-        esp32.add_idf_sdkconfig_option(
-            f"CONFIG_ESP_HOSTED_PRIV_SDIO_PIN_D1_4BIT_BUS_SLOT_{slot}",
-            config[CONF_D1_PIN],
-        )
-        esp32.add_idf_sdkconfig_option(
-            f"CONFIG_ESP_HOSTED_PRIV_SDIO_PIN_D2_4BIT_BUS_SLOT_{slot}",
-            config[CONF_D2_PIN],
-        )
-        esp32.add_idf_sdkconfig_option(
-            f"CONFIG_ESP_HOSTED_PRIV_SDIO_PIN_D3_4BIT_BUS_SLOT_{slot}",
-            config[CONF_D3_PIN],
-        )
-    esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_CUSTOM_SDIO_PINS", True)
-    esp32.add_idf_sdkconfig_option(
-        "CONFIG_ESP_HOSTED_SDIO_CLOCK_FREQ_KHZ",
-        int(config[CONF_SDIO_FREQUENCY] // 1000),
-    )
-
-
-def _configure_sdio_3x(config: ConfigType) -> None:
+def _configure_sdio(config: ConfigType) -> None:
     esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_HOST_TRANSPORT_BUS_SDIO", True)
     esp32.add_idf_sdkconfig_option(
         f"CONFIG_ESP_HOSTED_SDIO_SLOT_{config[CONF_SLOT]}",
@@ -283,10 +197,11 @@ def _configure_sdio_3x(config: ConfigType) -> None:
     esp32.add_idf_sdkconfig_option(
         "CONFIG_ESP_HOSTED_HOST_SDIO_PIN_D0", config[CONF_D0_PIN]
     )
+    # D1 carries the card interrupt on a 1-bit bus too
+    esp32.add_idf_sdkconfig_option(
+        "CONFIG_ESP_HOSTED_HOST_SDIO_PIN_D1", config[CONF_D1_PIN]
+    )
     if config[CONF_BUS_WIDTH] == 4:
-        esp32.add_idf_sdkconfig_option(
-            "CONFIG_ESP_HOSTED_HOST_SDIO_PIN_D1", config[CONF_D1_PIN]
-        )
         esp32.add_idf_sdkconfig_option(
             "CONFIG_ESP_HOSTED_HOST_SDIO_PIN_D2", config[CONF_D2_PIN]
         )
@@ -299,55 +214,7 @@ def _configure_sdio_3x(config: ConfigType) -> None:
     )
 
 
-def _configure_spi_2x(config: ConfigType) -> None:
-    esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_SPI_HOST_INTERFACE", True)
-    # SPI mode is set via per-variant choice options
-    variant = config[CONF_VARIANT]
-    mode = config[CONF_SPI_MODE]
-    suffix = "ESP32" if variant == "ESP32" else "ESP32XX"
-    esp32.add_idf_sdkconfig_option(
-        f"CONFIG_ESP_HOSTED_SPI_PRIV_MODE_{mode}_{suffix}",
-        True,
-    )
-    # Frequency is set via per-variant options
-    freq_mhz = int(config[CONF_FREQUENCY] // 1e6)
-    if variant == "ESP32":
-        esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_SPI_FREQ_ESP32", freq_mhz)
-    elif variant == "ESP32C6":
-        esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_SPI_FREQ_ESP32C6", freq_mhz)
-    else:
-        esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_SPI_FREQ_ESP32XX", freq_mhz)
-    # Pin configuration (use HSPI variant as P4/H2 hosts don't have VSPI)
-    esp32.add_idf_sdkconfig_option(
-        "CONFIG_ESP_HOSTED_SPI_HSPI_GPIO_MOSI", config[CONF_MOSI_PIN]
-    )
-    esp32.add_idf_sdkconfig_option(
-        "CONFIG_ESP_HOSTED_SPI_HSPI_GPIO_MISO", config[CONF_MISO_PIN]
-    )
-    esp32.add_idf_sdkconfig_option(
-        "CONFIG_ESP_HOSTED_SPI_HSPI_GPIO_CLK", config[CONF_CLK_PIN]
-    )
-    esp32.add_idf_sdkconfig_option(
-        "CONFIG_ESP_HOSTED_SPI_HSPI_GPIO_CS", config[CONF_CS_PIN]
-    )
-    esp32.add_idf_sdkconfig_option(
-        "CONFIG_ESP_HOSTED_SPI_GPIO_HANDSHAKE", config[CONF_HANDSHAKE_PIN]
-    )
-    esp32.add_idf_sdkconfig_option(
-        "CONFIG_ESP_HOSTED_SPI_GPIO_DATA_READY", config[CONF_DATA_READY_PIN]
-    )
-    # Handshake and data_ready polarity
-    if config[CONF_HANDSHAKE_ACTIVE_HIGH]:
-        esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_HS_ACTIVE_HIGH", True)
-    else:
-        esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_HS_ACTIVE_LOW", True)
-    if config[CONF_DATA_READY_ACTIVE_HIGH]:
-        esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_DR_ACTIVE_HIGH", True)
-    else:
-        esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_DR_ACTIVE_LOW", True)
-
-
-def _configure_spi_3x(config: ConfigType) -> None:
+def _configure_spi(config: ConfigType) -> None:
     esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_HOST_TRANSPORT_BUS_SPI", True)
     esp32.add_idf_sdkconfig_option(
         "CONFIG_ESP_HOSTED_HOST_SPI_MODE", config[CONF_SPI_MODE]
@@ -392,59 +259,28 @@ def _configure_spi_3x(config: ConfigType) -> None:
         )
 
 
-def _configure_2x(config: ConfigType) -> None:
-    transport_prefix = "SDIO" if config[CONF_TYPE] == "sdio" else "SPI"
-    # Reset polarity
-    if config[CONF_ACTIVE_HIGH]:
-        esp32.add_idf_sdkconfig_option(
-            f"CONFIG_ESP_HOSTED_{transport_prefix}_RESET_ACTIVE_HIGH", True
-        )
-    else:
-        esp32.add_idf_sdkconfig_option(
-            f"CONFIG_ESP_HOSTED_{transport_prefix}_RESET_ACTIVE_LOW", True
-        )
-    # Reset GPIO
+async def to_code(config: ConfigType) -> None:
+    add_define("USE_ESP32_HOSTED")
+    # The board choice defaults to an Espressif dev board, which locks every
+    # pin's Kconfig range to that board and silently drops other values
+    esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_P4_DEV_BOARD_NONE", True)
     esp32.add_idf_sdkconfig_option(
-        f"CONFIG_ESP_HOSTED_{transport_prefix}_GPIO_RESET_SLAVE",  # NOLINT
-        config[CONF_RESET_PIN],
+        "CONFIG_ESP_HOSTED_HOST_RESET_GPIO", config[CONF_RESET_PIN]
     )
-    # Slave variant  # NOLINT
+    # Co-processor variant. Wi-Fi Remote owns the choice and esp_hosted only
+    # offers the matching CP target, so both must name the same chip
     esp32.add_idf_sdkconfig_option(
         f"CONFIG_SLAVE_IDF_TARGET_{config[CONF_VARIANT]}",  # NOLINT
         True,
     )
-    if config[CONF_TYPE] == "sdio":
-        _configure_sdio_2x(config)
-    else:
-        _configure_spi_2x(config)
-    if esp32.get_esp32_variant() == esp32.VARIANT_ESP32P4:
-        # esp-hosted's CustomRpc ("peer data transfer") path — off by default.
-        esp32.add_idf_sdkconfig_option(
-            "CONFIG_ESP_HOSTED_ENABLE_PEER_DATA_TRANSFER", True
-        )
-        esp32.add_idf_sdkconfig_option(
-            "CONFIG_ESP_HOSTED_MAX_CUSTOM_MSG_HANDLERS", _MAX_CUSTOM_MSG_HANDLERS
-        )
-    # Place the transport mempool in PSRAM. Required on memory-tight host
-    # configurations (e.g. P4 with a large LVGL UI) where the internal-RAM
-    # mempool allocation fails at boot with `sdio_mempool_create` assert.
-    if config[CONF_USE_PSRAM]:
-        esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_MEMPOOL_PREFER_SPIRAM", True)
-
-
-def _configure_3x(config: ConfigType) -> None:
-    esp32.add_idf_sdkconfig_option(
-        "CONFIG_ESP_HOSTED_HOST_RESET_GPIO", config[CONF_RESET_PIN]
-    )
-    # Co-processor variant
     esp32.add_idf_sdkconfig_option(
         f"CONFIG_ESP_HOSTED_CP_TARGET_{config[CONF_VARIANT]}",
         True,
     )
     if config[CONF_TYPE] == "sdio":
-        _configure_sdio_3x(config)
+        _configure_sdio(config)
     else:
-        _configure_spi_3x(config)
+        _configure_spi(config)
     if esp32.get_esp32_variant() == esp32.VARIANT_ESP32P4:
         esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_HOST_FEAT_PEER_DATA", True)
         esp32.add_idf_sdkconfig_option(
@@ -455,16 +291,6 @@ def _configure_3x(config: ConfigType) -> None:
         esp32.add_idf_sdkconfig_option("CONFIG_EH_HOST_PORT_DMA_PREFER_SPIRAM", True)
         esp32.add_idf_sdkconfig_option("CONFIG_ESP_HOSTED_DFLT_TASK_FROM_SPIRAM", True)
 
-
-async def to_code(config: ConfigType) -> None:
-    add_define("USE_ESP32_HOSTED")
-    use_3x = uses_esp_hosted_3x()
-
-    if use_3x:
-        _configure_3x(config)
-    else:
-        _configure_2x(config)
-
     # ESP-NOW-over-hosted shim: only the radio-less ESP32-P4 host needs it (see
     # the note by _MAX_CUSTOM_MSG_HANDLERS). Enabled for every P4 host, not
     # gated on the `espnow` component being present: the shim is tiny and the
@@ -478,14 +304,14 @@ async def to_code(config: ConfigType) -> None:
         # esp_now_hosted.cpp includes esp_now.h, which esp_wifi provides
         esp32.include_builtin_idf_component("esp_wifi")
 
-    # Library versions; this component set requires ESP-IDF 5.3 or newer,
+    # Library versions; this component set requires ESP-IDF 5.5 or newer,
     # which is enforced at validation time.
     idf_ver = esp32.idf_version()
     os.environ["ESP_IDF_VERSION"] = f"{idf_ver.major}.{idf_ver.minor}"
     esp32.add_idf_component(name="espressif/esp_wifi_remote", ref="1.6.5")
     esp32.add_idf_component(name="espressif/wifi_remote_over_eppp", ref="0.3.3")
     esp32.add_idf_component(name="espressif/eppp_link", ref="1.1.5")
-    esp32.add_idf_component(name="espressif/esp_hosted", ref="2.12.13")
+    esp32.add_idf_component(name="espressif/esp_hosted", ref="3.0.10")
     esp32.add_extra_script(
         "post",
         "esp32_hosted.py",

esphome/components/esp32_hosted/update/__init__.py

@@ -1,12 +1,22 @@
 import hashlib
+import logging
+from pathlib import Path
+from tempfile import TemporaryDirectory
+import time
 from typing import Any
 
+import voluptuous as vol
+
+from esphome import external_files
 import esphome.codegen as cg
 from esphome.components import esp32, update
 from esphome.components.const import CONF_SHA256
 import esphome.config_validation as cv
-from esphome.const import CONF_ID, CONF_PATH, CONF_SOURCE, CONF_TYPE
+from esphome.const import CONF_ID, CONF_PATH, CONF_SOURCE, CONF_TYPE, CONF_URL
 from esphome.core import CORE, ID, HexInt
+from esphome.types import ConfigType
+
+_LOGGER = logging.getLogger(__name__)
 
 CODEOWNERS = ["@swoboda1337"]
 AUTO_LOAD = ["sha256", "watchdog", "json"]
@@ -40,11 +50,15 @@ BASE_SCHEMA = update.update_schema(Esp32HostedUpdate, device_class="firmware").e
     cv.polling_component_schema("6h")
 )
 
-EMBEDDED_SCHEMA = BASE_SCHEMA.extend(
-    {
-        cv.Required(CONF_PATH): cv.file_,
-        cv.Required(CONF_SHA256): _validate_sha256,
-    }
+EMBEDDED_SCHEMA = cv.All(
+    BASE_SCHEMA.extend(
+        {
+            cv.Optional(CONF_PATH): cv.file_,
+            cv.Optional(CONF_URL): cv.All(cv.url, vol.Match(r"^https?://")),
+            cv.Required(CONF_SHA256): _validate_sha256,
+        }
+    ),
+    cv.has_exactly_one_key(CONF_PATH, CONF_URL),
 )
 
 HTTP_SCHEMA = BASE_SCHEMA.extend(
@@ -70,21 +84,74 @@ CONFIG_SCHEMA = cv.All(
 )
 
 
-def _validate_firmware(config: dict[str, Any]) -> None:
-    if config[CONF_TYPE] != TYPE_EMBEDDED:
-        return
+# The other build's rename finishes within milliseconds; a few short checks cover it
+CACHE_RACE_RETRIES = 5
+CACHE_RACE_RETRY_S = 0.05
 
-    path = CORE.relative_config_path(config[CONF_PATH])
-    with path.open("rb") as f:
-        firmware_data = f.read()
-    calculated = hashlib.sha256(firmware_data).hexdigest()
-    expected = config[CONF_SHA256].lower()
+
+def _check_firmware_hash(data: bytes, expected: str, source: str | Path) -> None:
+    calculated = hashlib.sha256(data).hexdigest()
     if calculated != expected:
         raise cv.Invalid(
-            f"SHA256 mismatch for {config[CONF_PATH]}: expected {expected}, got {calculated}"
+            f"SHA256 mismatch for {source}: expected {expected}, got {calculated}"
         )
 
 
+def _cached_image_digest(target: Path) -> str | None:
+    """The SHA256 of the cached image, or None while it is missing or another build still writes it."""
+    try:
+        return hashlib.sha256(target.read_bytes()).hexdigest()
+    except OSError:
+        return None
+
+
+def _firmware_path(config: ConfigType) -> Path:
+    """The configured image file, or the cache slot of the pinned digest for a downloaded one."""
+    if CONF_URL in config:
+        cache_dir = external_files.compute_local_file_dir("esp32_hosted") / "firmware"
+        return cache_dir / f"{config[CONF_SHA256].lower()}.bin"
+    return CORE.relative_config_path(config[CONF_PATH])
+
+
+def _validate_firmware(config: ConfigType) -> None:
+    """Fetch and verify the image here; codegen only reads the file this leaves behind."""
+    if config[CONF_TYPE] != TYPE_EMBEDDED:
+        return
+    expected = config[CONF_SHA256].lower()
+    target = _firmware_path(config)
+    if (url := config.get(CONF_URL)) is None:
+        _check_firmware_hash(target.read_bytes(), expected, target)
+        return
+    # A pinned digest needs no remote freshness check.
+    if (actual := _cached_image_digest(target)) == expected:
+        return
+    if actual is not None:
+        # Named after its digest, so a mismatch means the file was damaged or edited
+        _LOGGER.warning(
+            "Cached firmware %s hashes to %s, downloading it again", target, actual
+        )
+    target.parent.mkdir(parents=True, exist_ok=True)
+    # Keep unverified bytes out of the shared cache, even across concurrent builds.
+    with TemporaryDirectory(dir=target.parent) as temporary:
+        candidate = Path(temporary) / "firmware.bin"
+        data = external_files.download_content(url, candidate, allow_stale=False)
+        _check_firmware_hash(data, expected, url)
+        for attempt in range(CACHE_RACE_RETRIES + 1):
+            try:
+                candidate.replace(target)
+                return
+            except OSError as err:
+                # Windows refuses to replace a file another build holds at that moment; retry, or
+                # take that build's copy: named after its digest, a verified one is the same image
+                if _cached_image_digest(target) == expected:
+                    return
+                if attempt == CACHE_RACE_RETRIES:
+                    raise cv.Invalid(
+                        f"Could not cache the firmware from {url}: {err}"
+                    ) from err
+                time.sleep(CACHE_RACE_RETRY_S)
+
+
 FINAL_VALIDATE_SCHEMA = _validate_firmware
 
 
@@ -92,9 +159,7 @@ async def to_code(config: dict[str, Any]) -> None:
     var = await update.new_update(config)
 
     if config[CONF_TYPE] == TYPE_EMBEDDED:
-        path = config[CONF_PATH]
-        with CORE.relative_config_path(path).open("rb") as f:
-            firmware_data = f.read()
+        firmware_data = _firmware_path(config).read_bytes()
         rhs = [HexInt(x) for x in firmware_data]
         arr_id = ID(f"{config[CONF_ID]}_data", is_declaration=True, type=cg.uint8)
         prog_arr = cg.progmem_array(arr_id, rhs)

esphome/components/esp32_hosted/update/esp32_hosted_update.cpp

@@ -24,8 +24,8 @@ namespace esphome::esp32_hosted {
 
 ESPHOME_LOG_TAG(TAG, "esp32_hosted.update");
 
-// Older coprocessor firmware versions have a 1500-byte limit per RPC call
-constexpr size_t CHUNK_SIZE = 1500;
+// The host rejects writes above its per-RPC payload limit before they reach the coprocessor
+constexpr size_t CHUNK_SIZE = EH_HOST_CP_OTA_CHUNK_MAX;
 // OTA begin blocks while the coprocessor erases its partition, end while it validates the image
 constexpr uint32_t OTA_WDT_TIMEOUT_MS = 60000;
 

esphome/components/esphome/ota/ota_esphome_udp.cpp

@@ -222,10 +222,13 @@ void ESPHomeOTAComponent::udp_open_(UdpLink &link) {
   if (!random_bytes(token, sizeof(token)))
     return;
 #ifdef ESPHOME_OTA_UDP_LWIP
+#if USE_NETWORK_IPV4
   uint32_t ipv4;
   if (socket::sockaddr_to_ipv4(reinterpret_cast<const struct sockaddr *>(&peer), &ipv4)) {
     ip_addr_set_ip4_u32(&link.peer_ip, ipv4);
-  } else {
+  } else
+#endif
+  {
 #if USE_NETWORK_IPV6 && LWIP_IPV6
     inet6_addr_to_ip6addr(ip_2_ip6(&link.peer_ip), &reinterpret_cast<const sockaddr_in6 *>(&peer)->sin6_addr);
     IP_SET_TYPE_VAL(link.peer_ip, IPADDR_TYPE_V6);