Add chip temperature sensor and RGB LED control, verified live in HA

Quick end-to-end data-flow proof using only what's on the ESP32-C6-
DevKitC-1 itself (no sensors on the bare devkit -- confirmed via
research: BOOT button, WS2812 LED, no external sensors):

- drivers::chip_temperature_* wraps ESP-IDF's built-in
  temperature_sensor driver (SoC die temperature).
- drivers::rgb_led_* wraps the onboard WS2812 (GPIO8) via the
  espressif/led_strip managed component (another external registry
  dependency, like mdns/mqtt).
- profiles::ChipTemperatureSensor is the first real implementation of
  the Sensor interface designed earlier, converting the driver's float
  reading to the fixed-point convention once at the boundary.
- transport/mqtt.cpp publishes chip temperature as an HA "temperature"
  sensor every 30s, and exposes the LED as an HA "light" entity
  (rgb_command_topic) -- the first use of MQTT subscribe in this
  project, not just publish.

Added a ChipTemperature SensorChannel (distinct from
AmbientTemperature -- different meaning/range) to sensor.h.

Verified live: both the chip temperature reading and LED color control
work from Home Assistant against the real device.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

components/drivers/CMakeLists.txt

@@ -1,2 +1,5 @@
-idf_component_register()
-
+idf_component_register(
+    SRCS "src/chip_temperature.cpp" "src/rgb_led.cpp"
+    INCLUDE_DIRS "include"
+    PRIV_REQUIRES esp_driver_tsens espressif__led_strip
+)

components/drivers/README.md

@@ -2,4 +2,7 @@
 
 Hardware abstraction: wraps ESP32-C6 peripherals (GPIO, ADC, I2C) behind a board-independent interface used by `sensors`. No dependency on other Kvida components.
 
+- `chip_temperature.h`/`.cpp` -- wraps ESP-IDF's built-in `temperature_sensor` driver (die temperature; there's no external ambient temperature sensor on the ESP32-C6-DevKitC-1).
+- `rgb_led.h`/`.cpp` -- wraps the DevKitC-1's onboard WS2812 addressable RGB LED (GPIO8) via the `espressif/led_strip` managed component (`idf_component.yml`).
+
 TODO: mounting the `storage` LittleFS partition (see `partitions.csv`) belongs here once a LittleFS component (e.g. `joltwallet/esp_littlefs` from the IDF Component Registry) is picked and pinned via `idf_component.yml`.

components/drivers/idf_component.yml

@@ -0,0 +1,3 @@
+dependencies:
+  espressif/led_strip:
+    version: "*"

components/drivers/include/chip_temperature.h

@@ -0,0 +1,11 @@
+#pragma once
+
+namespace kvida::drivers {
+
+// Wraps ESP-IDF's temperature_sensor driver (die temperature, not
+// ambient -- there is no external temperature sensor on the ESP32-C6
+// DevKitC). Call init() once before read_celsius().
+void chip_temperature_init();
+float chip_temperature_read_celsius();
+
+} // namespace kvida::drivers

components/drivers/include/rgb_led.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <cstdint>
+
+namespace kvida::drivers {
+
+// Wraps the WS2812 addressable RGB LED on the ESP32-C6-DevKitC-1 (GPIO8).
+void rgb_led_init();
+void rgb_led_set_color(uint8_t red, uint8_t green, uint8_t blue);
+
+} // namespace kvida::drivers

components/drivers/src/chip_temperature.cpp

@@ -0,0 +1,37 @@
+#include "chip_temperature.h"
+
+#include "driver/temperature_sensor.h"
+#include "esp_log.h"
+
+namespace kvida::drivers {
+
+namespace {
+constexpr const char *TAG = "chip_temperature";
+temperature_sensor_handle_t g_handle = nullptr;
+} // namespace
+
+void chip_temperature_init()
+{
+    if (g_handle) {
+        return;
+    }
+    temperature_sensor_config_t cfg = TEMPERATURE_SENSOR_CONFIG_DEFAULT(-10, 80);
+    ESP_ERROR_CHECK(temperature_sensor_install(&cfg, &g_handle));
+    ESP_ERROR_CHECK(temperature_sensor_enable(g_handle));
+}
+
+float chip_temperature_read_celsius()
+{
+    if (!g_handle) {
+        ESP_LOGE(TAG, "chip_temperature_read_celsius() called before chip_temperature_init()");
+        return 0.0f;
+    }
+    float celsius = 0.0f;
+    esp_err_t err = temperature_sensor_get_celsius(g_handle, &celsius);
+    if (err != ESP_OK) {
+        ESP_LOGW(TAG, "temperature_sensor_get_celsius failed: %s", esp_err_to_name(err));
+    }
+    return celsius;
+}
+
+} // namespace kvida::drivers

components/drivers/src/rgb_led.cpp

@@ -0,0 +1,47 @@
+#include "rgb_led.h"
+
+#include "esp_log.h"
+#include "led_strip.h"
+
+namespace kvida::drivers {
+
+namespace {
+constexpr const char *TAG = "rgb_led";
+constexpr int kGpio = 8; // WS2812 on ESP32-C6-DevKitC-1
+led_strip_handle_t g_strip = nullptr;
+} // namespace
+
+void rgb_led_init()
+{
+    if (g_strip) {
+        return;
+    }
+
+    led_strip_config_t strip_config = {};
+    strip_config.strip_gpio_num = kGpio;
+    strip_config.max_leds = 1;
+    strip_config.led_model = LED_MODEL_WS2812;
+    strip_config.color_component_format = LED_STRIP_COLOR_COMPONENT_FMT_GRB;
+
+    led_strip_rmt_config_t rmt_config = {};
+    rmt_config.resolution_hz = 10 * 1000 * 1000;
+
+    esp_err_t err = led_strip_new_rmt_device(&strip_config, &rmt_config, &g_strip);
+    if (err != ESP_OK) {
+        ESP_LOGE(TAG, "led_strip_new_rmt_device failed: %s", esp_err_to_name(err));
+        return;
+    }
+    led_strip_clear(g_strip);
+}
+
+void rgb_led_set_color(uint8_t red, uint8_t green, uint8_t blue)
+{
+    if (!g_strip) {
+        ESP_LOGE(TAG, "rgb_led_set_color() called before rgb_led_init()");
+        return;
+    }
+    led_strip_set_pixel(g_strip, 0, red, green, blue);
+    led_strip_refresh(g_strip);
+}
+
+} // namespace kvida::drivers

components/profiles/CMakeLists.txt

@@ -1,3 +1,5 @@
 idf_component_register(
-    REQUIRES sensors
+    SRCS "src/chip_temperature_sensor.cpp"
+    INCLUDE_DIRS "include"
+    REQUIRES sensors drivers
 )

components/profiles/README.md

@@ -1,3 +1,7 @@
 # profiles
 
 Exposes reusable sensor/actuator capabilities (reed switch, hall sensor, push button, pulse counter, analog input, DS18B20, BME280, leak sensor, PIR, generic I2C device) to the Lua runtime, backed by `sensors`. `REQUIRES sensors`.
+
+Concrete `Sensor` implementations live here (not in `sensors`, which owns the shared interface/types), and reach down to `drivers` directly for the actual hardware access -- `sensors` is the shared contract, not a mandatory pass-through. `REQUIRES drivers` too.
+
+- `ChipTemperatureSensor` (`include/chip_temperature_sensor.h`) -- the first real `Sensor` implementation, wrapping `drivers::chip_temperature_*` (the ESP32-C6's internal die temperature). Added to get real data flowing end-to-end (drivers -> profiles -> transport/MQTT) before more sensor types exist.

components/profiles/include/chip_temperature_sensor.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include "sensor.h"
+
+namespace kvida {
+
+// First real implementation of the Sensor interface (see
+// components/sensors/include/sensor.h) -- wraps the ESP32-C6's internal
+// die temperature sensor (kvida::drivers::chip_temperature_*).
+class ChipTemperatureSensor : public Sensor {
+public:
+    const char *id() const override { return "chip_temperature"; }
+    void begin() override;
+
+    bool supports(SensorChannel channel) const override
+    {
+        return channel == SensorChannel::ChipTemperature;
+    }
+
+    bool fetch() override;
+    bool get(SensorChannel channel, SensorValue &out) override;
+
+private:
+    bool fetched_ = false;
+    SensorValue last_{};
+};
+
+} // namespace kvida

components/profiles/src/chip_temperature_sensor.cpp

@@ -0,0 +1,36 @@
+#include "chip_temperature_sensor.h"
+
+#include "chip_temperature.h"
+
+namespace kvida {
+
+void ChipTemperatureSensor::begin()
+{
+    drivers::chip_temperature_init();
+}
+
+bool ChipTemperatureSensor::fetch()
+{
+    float celsius = drivers::chip_temperature_read_celsius();
+
+    // Convert to the fixed-point convention (val1 + val2 * 1e-6) once, at
+    // the boundary where the underlying driver hands us a float --
+    // ESP32-C6 has no hardware FPU, see sensor.h.
+    auto val1 = static_cast<int32_t>(celsius);
+    auto val2 = static_cast<int32_t>((celsius - static_cast<float>(val1)) * 1000000.0f);
+
+    last_ = SensorValue{val1, val2, "C", 0};
+    fetched_ = true;
+    return true;
+}
+
+bool ChipTemperatureSensor::get(SensorChannel channel, SensorValue &out)
+{
+    if (!fetched_ || channel != SensorChannel::ChipTemperature) {
+        return false;
+    }
+    out = last_;
+    return true;
+}
+
+} // namespace kvida

components/sensors/include/sensor.h

@@ -11,6 +11,7 @@ enum class SensorChannel {
     Contact,
     Motion,
     AmbientTemperature,
+    ChipTemperature, // SoC die temperature, e.g. ESP32-C6's internal sensor -- distinct from AmbientTemperature since the value range/meaning differ
     Humidity,
     Pressure,
     AccelX,

components/transport/include/mqtt.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <cstdint>
+
 namespace kvida {
 
 // Starts mDNS-based MQTT broker discovery (_mqtt._tcp) and, once found,
@@ -12,4 +14,16 @@ void start_mqtt();
 
 bool mqtt_connected();
 
+// Publishes (retained) Home Assistant MQTT Discovery for a diagnostic
+// "Chip temperature" sensor on first call, then the reading itself.
+// Quick end-to-end proof that a real Sensor implementation's data can
+// reach MQTT/HA -- not the eventual generic publish(topic, value) API.
+void publish_chip_temperature(float celsius);
+
+// Registered by main to receive "set LED color" commands from Home
+// Assistant (an RGB light entity) without transport depending on
+// `drivers` directly.
+using LedColorHandler = void (*)(uint8_t red, uint8_t green, uint8_t blue);
+void set_led_color_handler(LedColorHandler handler);
+
 } // namespace kvida

components/transport/src/mqtt.cpp

@@ -33,10 +33,19 @@ std::atomic<bool> g_connected{false};
 esp_mqtt_client_handle_t g_client = nullptr;
 esp_timer_handle_t g_retry_timer = nullptr;
 httpd_handle_t g_settings_httpd = nullptr;
+LedColorHandler g_led_handler = nullptr;
 
 char g_availability_topic[48];
 char g_discovery_topic[80];
 char g_discovery_payload[512];
+
+char g_temp_state_topic[48];
+char g_led_command_topic[48];
+char g_led_rgb_command_topic[48];
+char g_led_state_topic[48];
+char g_led_rgb_state_topic[48];
+bool g_led_discovery_published = false;
+bool g_led_on = false;
 // Remembered so a settings update can reconnect without re-running mDNS
 // discovery.
 char g_broker_uri[96]; // "mqtt://" + up to 63-char host + ":" + port + NUL
@@ -149,18 +158,106 @@ void publish_discovery_and_birth()
     esp_mqtt_client_publish(g_client, g_availability_topic, "online", 0, 1, true);
 }
 
-void mqtt_event_handler(void * /*arg*/, esp_event_base_t /*base*/, int32_t event_id, void * /*event_data*/)
+// Publishes HA MQTT Discovery for an RGB light entity (once) and
+// (re)subscribes to its command topics -- topic subscriptions don't
+// survive a client reconnect, so this runs on every MQTT_EVENT_CONNECTED,
+// not just the first.
+void publish_led_discovery_and_subscribe()
+{
+    char id[16];
+    device_id(id, sizeof(id));
+
+    snprintf(g_led_command_topic, sizeof(g_led_command_topic), "kvida/%s/led/set", id);
+    snprintf(g_led_rgb_command_topic, sizeof(g_led_rgb_command_topic), "kvida/%s/led/rgb/set", id);
+    snprintf(g_led_state_topic, sizeof(g_led_state_topic), "kvida/%s/led/state", id);
+    snprintf(g_led_rgb_state_topic, sizeof(g_led_rgb_state_topic), "kvida/%s/led/rgb/state", id);
+
+    if (!g_led_discovery_published) {
+        char discovery_topic[80];
+        snprintf(discovery_topic, sizeof(discovery_topic), "homeassistant/light/%s/led/config", id);
+
+        char payload[640];
+        snprintf(payload, sizeof(payload),
+                 "{"
+                 "\"name\":\"LED\","
+                 "\"unique_id\":\"%s_led\","
+                 "\"command_topic\":\"%s\","
+                 "\"state_topic\":\"%s\","
+                 "\"rgb_command_topic\":\"%s\","
+                 "\"rgb_state_topic\":\"%s\","
+                 "\"payload_on\":\"ON\","
+                 "\"payload_off\":\"OFF\","
+                 "\"availability_topic\":\"%s\","
+                 "\"payload_available\":\"online\","
+                 "\"payload_not_available\":\"offline\","
+                 "\"device\":{"
+                 "\"identifiers\":[\"%s\"],"
+                 "\"name\":\"%s\","
+                 "\"manufacturer\":\"Xylon\","
+                 "\"model\":\"Kvida\""
+                 "}"
+                 "}",
+                 id, g_led_command_topic, g_led_state_topic, g_led_rgb_command_topic, g_led_rgb_state_topic,
+                 g_availability_topic, id, id);
+
+        esp_mqtt_client_publish(g_client, discovery_topic, payload, 0, 1, true);
+        g_led_discovery_published = true;
+    }
+
+    esp_mqtt_client_subscribe(g_client, g_led_command_topic, 1);
+    esp_mqtt_client_subscribe(g_client, g_led_rgb_command_topic, 1);
+}
+
+void handle_led_data(const char *topic, size_t topic_len, const char *data, size_t data_len)
+{
+    char payload[32] = {0};
+    size_t n = data_len < sizeof(payload) - 1 ? data_len : sizeof(payload) - 1;
+    memcpy(payload, data, n);
+    payload[n] = '\0';
+
+    bool is_power = topic_len == strlen(g_led_command_topic) && memcmp(topic, g_led_command_topic, topic_len) == 0;
+    bool is_rgb =
+        topic_len == strlen(g_led_rgb_command_topic) && memcmp(topic, g_led_rgb_command_topic, topic_len) == 0;
+
+    if (is_power) {
+        g_led_on = strcmp(payload, "ON") == 0;
+        if (!g_led_on && g_led_handler) {
+            g_led_handler(0, 0, 0);
+        }
+        esp_mqtt_client_publish(g_client, g_led_state_topic, g_led_on ? "ON" : "OFF", 0, 1, true);
+    } else if (is_rgb) {
+        // Home Assistant's classic (non-JSON) rgb_command_topic schema
+        // sends "R,G,B".
+        int r = 0, g = 0, b = 0;
+        if (sscanf(payload, "%d,%d,%d", &r, &g, &b) == 3) {
+            g_led_on = true;
+            if (g_led_handler) {
+                g_led_handler(static_cast<uint8_t>(r), static_cast<uint8_t>(g), static_cast<uint8_t>(b));
+            }
+            esp_mqtt_client_publish(g_client, g_led_state_topic, "ON", 0, 1, true);
+            esp_mqtt_client_publish(g_client, g_led_rgb_state_topic, payload, 0, 1, true);
+        }
+    }
+}
+
+void mqtt_event_handler(void * /*arg*/, esp_event_base_t /*base*/, int32_t event_id, void *event_data)
 {
     switch (static_cast<esp_mqtt_event_id_t>(event_id)) {
     case MQTT_EVENT_CONNECTED:
         ESP_LOGI(TAG, "MQTT connected");
         g_connected.store(true);
         publish_discovery_and_birth();
+        publish_led_discovery_and_subscribe();
         break;
     case MQTT_EVENT_DISCONNECTED:
         ESP_LOGW(TAG, "MQTT disconnected");
         g_connected.store(false);
         break;
+    case MQTT_EVENT_DATA: {
+        auto *event = static_cast<esp_mqtt_event_handle_t>(event_data);
+        handle_led_data(event->topic, event->topic_len, event->data, event->data_len);
+        break;
+    }
     default:
         break;
     }
@@ -411,4 +508,55 @@ bool mqtt_connected()
     return g_connected.load();
 }
 
+void publish_chip_temperature(float celsius)
+{
+    if (!g_client || !g_connected.load()) {
+        return;
+    }
+
+    char id[16];
+    device_id(id, sizeof(id));
+    snprintf(g_temp_state_topic, sizeof(g_temp_state_topic), "kvida/%s/chip_temperature", id);
+
+    static bool discovery_published = false;
+    if (!discovery_published) {
+        char discovery_topic[80];
+        snprintf(discovery_topic, sizeof(discovery_topic),
+                 "homeassistant/sensor/%s/chip_temperature/config", id);
+
+        char payload[512];
+        snprintf(payload, sizeof(payload),
+                 "{"
+                 "\"name\":\"Chip temperature\","
+                 "\"device_class\":\"temperature\","
+                 "\"unit_of_measurement\":\"\xc2\xb0"
+                 "C\","
+                 "\"unique_id\":\"%s_chip_temperature\","
+                 "\"state_topic\":\"%s\","
+                 "\"availability_topic\":\"%s\","
+                 "\"payload_available\":\"online\","
+                 "\"payload_not_available\":\"offline\","
+                 "\"device\":{"
+                 "\"identifiers\":[\"%s\"],"
+                 "\"name\":\"%s\","
+                 "\"manufacturer\":\"Xylon\","
+                 "\"model\":\"Kvida\""
+                 "}"
+                 "}",
+                 id, g_temp_state_topic, g_availability_topic, id, id);
+
+        esp_mqtt_client_publish(g_client, discovery_topic, payload, 0, 1, true);
+        discovery_published = true;
+    }
+
+    char value[16];
+    snprintf(value, sizeof(value), "%.1f", static_cast<double>(celsius));
+    esp_mqtt_client_publish(g_client, g_temp_state_topic, value, 0, 0, false);
+}
+
+void set_led_color_handler(LedColorHandler handler)
+{
+    g_led_handler = handler;
+}
+
 } // namespace kvida