build: add the ESP32-C5

The C5 builds like the C6: a debug build with one 3 MB app slot, so it
updates over USB. At CORE_DEBUG_LEVEL=2 its image left 3.4 KB of the
1.5 MB OTA slot, under CI's 8 KB.

- platformio.ini: env esp32c5 (esp32-c5-devkitc-1).
- Chip model "c5", so the updater and releases name its files
  SomfyController.*.esp32c5.bin.
- Radio defaults: the framework's SPI pins (CSN 6, MOSI 8, MISO 9,
  SCK 10), TX 4, RX 5.
- Web UI: GPIO 0-28, without 13-14 (USB) and 15-22 (flash, PSRAM).
- CI builds and releases it; its bootloader sits at 0x2000.
- ADR 0003: amended.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.github/workflows/build.yaml

@@ -60,7 +60,7 @@ jobs:
         # fwname: firmware-only binary for OTA updates
         # obname: onboard image (bootloader + partitions + firmware + littlefs merged)
         #         for flashing a new chip via USB/serial
-        # addr_bootloader: chip-dependent (ESP32: 0x1000, S3/C3/C6: 0x0)
+        # addr_bootloader: chip-dependent (ESP32: 0x1000, S3/C3/C6: 0x0, C5: 0x2000)
         # addr_fs: must match spiffs/littlefs offset in esp32_3MB.csv
         include:
           - env: esp32dev
@@ -87,6 +87,14 @@ jobs:
             fwname: SomfyController.ino.esp32c3.bin
             fsname: SomfyController.littlefs.esp32c3.bin
             obname: SomfyController.onboard.esp32c3.bin
+          - env: esp32c5
+            name: ESP32-C5
+            chip: ESP32-C5
+            addr_bootloader: "0x2000"
+            addr_fs: "0x310000"
+            fwname: SomfyController.ino.esp32c5.bin
+            fsname: SomfyController.littlefs.esp32c5.bin
+            obname: SomfyController.onboard.esp32c5.bin
           - env: esp32c6
             name: ESP32-C6
             chip: ESP32-C6

data-src/index.js

@@ -2719,6 +2719,7 @@ class Somfy {
         { name: 's2', maxPins: 46, inputs: [0, 19, 20, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 45], outputs: [0, 19, 20, 26, 27, 28, 29, 30, 31, 32, 45, 46]},
         { name: 's3', maxPins: 48, inputs: [19, 20, 22, 23, 24, 25, 27, 28, 29, 30, 31, 32], outputs: [19, 20, 22, 23, 24, 25, 27, 28, 29, 30, 31, 32] },
         { name: 'c3', maxPins: 21, inputs: [11, 12, 13, 14, 15, 16, 17, 18, 19, 20], outputs: [11, 12, 13, 14, 15, 16, 17, 21] },
+        { name: 'c5', maxPins: 28, inputs: [13, 14, 15, 16, 17, 18, 19, 20, 21, 22], outputs: [13, 14, 15, 16, 17, 18, 19, 20, 21, 22] },
         { name: 'c6', maxPins: 23, inputs: [], outputs: [] }
     ];
 

docs/adr/0003-pioarduino-idf55.md

@@ -13,7 +13,7 @@ We moved every firmware env from `espressif32 @ 6.13.0` (Arduino 2.0.17 on ESP-I
 - **Firmware size.** The ESP32 image grows from 1,382,640 bytes (v3.0.14) to 1,555,472 at `CORE_DEBUG_LEVEL=2`, leaving 17 KB of the 1.5 MB OTA slot. At level 3 it doesn't fit, so release envs build at level 2 (warnings and errors) and debug envs stay at 3. PlatformIO's "Flash:" figure counts ELF sections, not the image, and reads about 45 KB low, so CI checks `firmware.bin` against the app partition and fails under 8 KB free (`.github/size_check.py`).
 - **No more C3 builds.** Its image grows by 214 KB to 1,651,216 bytes, 76.5 KB over the OTA slot even at level 2. C3 boards stay on the 3.0.x releases.
 
-  > **Amended in 4.0.0.** The C3 builds again. Without the old API (ports 8080 and 8081), its image is 1,498,512 bytes at level 2 and leaves 72.6 KB of the OTA slot.
+  > **Amended in 4.0.0.** The C3 builds again. Without the old API (ports 8080 and 8081), its image is 1,498,512 bytes at level 2 and leaves 72.6 KB of the OTA slot. The C5 is new in 4.0.0 and builds like the C6: a debug build with one 3 MB app slot, updated over USB, since at level 2 its image left only 3.4 KB of the OTA slot.
 - **Ethernet PHY ids are ours.** Arduino 3.x renumbered `eth_phy_type_t` (`ETH_PHY_GENERIC` is 0). NVS, backups and the web UI keep the Arduino 2.x numbers as `eth_phy_id_t` (`src/EthPhy.h`), translated by name when Ethernet starts. Never cast a stored id to the framework enum.
 - **Ethernet only on the original ESP32.** Arduino 3.x has the RMII MAC API only where `CONFIG_ETH_USE_ESP32_EMAC` is set. S3 and C6 build without Ethernet.
 - **Updates roll back until proven.** We override the core's `verifyRollbackLater()` hook to return true, and `loop()` marks the new firmware valid once it has run 60 s and the network is up. A reset before then boots the previous firmware. The LittleFS image an update wrote stays, so the old firmware runs with the new web UI.

platformio.ini

@@ -103,6 +103,18 @@ build_flags =
 	${esp32.build_flags}
 	-DCORE_DEBUG_LEVEL=2
 
+; Released as a debug build with one 3 MB app slot, so C5 and C6 boards
+; update over USB, not OTA.  The C5's image leaves 3.4 KB of the 1.5 MB OTA
+; slot even at level 2.
+[env:esp32c5]
+extends = esp32
+board = esp32-c5-devkitc-1
+build_type = debug
+board_build.partitions = esp32_huge_app.csv
+build_flags =
+	${esp32.build_flags}
+	-DCORE_DEBUG_LEVEL=3
+
 ; Released as a debug build with one 3 MB app slot, so C6 boards update over
 ; USB, not OTA.
 [env:esp32c6]

src/ConfigSettings.cpp

@@ -134,6 +134,11 @@ bool ConfigSettings::begin() {
     case esp_chip_model_t::CHIP_ESP32C3:
       strcpy(this->chipModel, "c3");
       break;
+    #ifdef CONFIG_IDF_TARGET_ESP32C5
+    case esp_chip_model_t::CHIP_ESP32C5:
+      strcpy(this->chipModel, "c5");
+      break;
+    #endif
     #ifdef CONFIG_IDF_TARGET_ESP32C6
     case esp_chip_model_t::CHIP_ESP32C6:
       strcpy(this->chipModel, "c6");

src/EthPhy.h

@@ -5,8 +5,8 @@
 #include <sdkconfig.h>
 #endif
 
-// Ethernet needs the RMII MAC, which only the original ESP32 has.  The C3, S3
+// Ethernet needs the RMII MAC, which only the original ESP32 has.  The C3, C5,
-// and C6 build without it.
+// S3 and C6 build without it.
 #if defined(CONFIG_ETH_USE_ESP32_EMAC) && CONFIG_ETH_USE_ESP32_EMAC
 #define HAS_ETHERNET 1
 #else

src/Transceiver.cpp

@@ -481,6 +481,18 @@ void transceiver_config_t::load() {
         this->SCKPin = 15;
         this->CSNPin = 14;
         break;
+#ifdef CONFIG_IDF_TARGET_ESP32C5
+      case esp_chip_model_t::CHIP_ESP32C5:
+        // The framework's default SPI pins (variants/esp32c5).  4 and 5 aren't
+        // strapping pins.
+        this->TXPin = 4;
+        this->RXPin = 5;
+        this->MOSIPin = 8;
+        this->MISOPin = 9;
+        this->SCKPin = 10;
+        this->CSNPin = 6;
+        break;
+#endif
 #ifdef CONFIG_IDF_TARGET_ESP32C6
       case esp_chip_model_t::CHIP_ESP32C6:
       // Pinout applicable for the ESP32-C6-WROOM-1 module (ESP32-C6-DevKitC-1-N4)

src/Utils.h

@@ -85,7 +85,7 @@ const char *wifiAuthModeName(uint8_t authMode);
 bool otaProven(bool networkUp, unsigned long uptimeMs, unsigned long minUptimeMs);
 // A release asset's name: "SomfyController.<kind>.esp32<chipModel>.bin", kind
 // "ino" for the firmware or "littlefs" for the web UI image, chipModel as in
-// ConfigSettings ("" for the ESP32, "s3", "c3", "c6").
+// ConfigSettings ("" for the ESP32, "s3", "c3", "c5", "c6").
 void releaseAssetName(char *buf, size_t size, const char *kind, const char *chipModel);
 // A coredump backtrace as " 0x%08x" per frame.  bt holds maxFrames entries and
 // depth is how many the dump claims are valid.

test/test_utils/test_utils.cpp

@@ -280,6 +280,8 @@ static void test_releaseAssetName_matches_the_release_workflow() {
   TEST_ASSERT_EQUAL_STRING("SomfyController.littlefs.esp32s3.bin", buf);
   releaseAssetName(buf, sizeof(buf), "ino", "c3");
   TEST_ASSERT_EQUAL_STRING("SomfyController.ino.esp32c3.bin", buf);
+  releaseAssetName(buf, sizeof(buf), "ino", "c5");
+  TEST_ASSERT_EQUAL_STRING("SomfyController.ino.esp32c5.bin", buf);
   releaseAssetName(buf, sizeof(buf), "littlefs", "c6");
   TEST_ASSERT_EQUAL_STRING("SomfyController.littlefs.esp32c6.bin", buf);
 }