Usermod: Add support for Si7021 temperature and humidity sensors (#2617)

* added first version (work in progress)

* added some sensors to publish

* typo

* added dependency

* mqtt si7021_* names + don't  retain

* timer to 60 s

* some changes to HA auto discovery

* added config entries (no function yet)

* renaming

* made configs work

* added getId()

* refactoring + wrong mqtt topics fixed

* retain HA auto discovery

* do not spam serial console on each sensor update

* added readme

* add update interval info

Co-authored-by: Christian Schwinne <dev.aircoookie@gmail.com>

usermods/Si7021_MQTT_HA/readme.md

@@ -0,0 +1,69 @@
+# Si7021 to MQTT (with Home Assistant Auto Discovery) usermod
+
+This usermod implements support for [Si7021 I²C temperature and humidity sensors](https://www.silabs.com/documents/public/data-sheets/Si7021-A20.pdf).
+
+The sensor data will *not* be shown on the WLED UI (so far) but published via MQTT to WLED's "build in" MQTT device topic. 
+
+```
+temperature: $mqttDeviceTopic/si7021_temperature
+humidity: $mqttDeviceTopic/si7021_humidity
+```
+
+Additionally the following sensors can be published:
+
+```
+heat_index: $mqttDeviceTopic/si7021_heat_index
+dew_point: $mqttDeviceTopic/si7021_dew_point
+absolute_humidity: $mqttDeviceTopic/si7021_absolute_humidity
+```
+
+Sensor data will be updated/send every 60 seconds.
+
+This usermod also supports Home Assistant Auto Discovery.
+
+## Settings via Usermod Setup
+
+- `enabled`: Enables this usermod
+- `Send Dew Point, Abs. Humidity and Heat Index`: Enables additional sensors
+- `Home Assistant MQTT Auto-Discovery`: Enables Home Assistant Auto Discovery
+
+# Installation
+
+## Hardware
+
+Attach the Si7021 sensor to the I²C interface.
+
+Default PINs ESP32:
+
+```
+SCL_PIN = 22;
+SDA_PIN = 21;
+```
+
+Default PINs ESP8266:
+
+```
+SCL_PIN = 5;
+SDA_PIN = 4;
+```
+
+## Software
+
+Add to `build_flags` in platformio.ini:
+
+```
+   -D USERMOD_SI7021_MQTT_HA
+```
+
+Add to `lib_deps` in platformio.ini:
+
+```
+   adafruit/Adafruit Si7021 Library @ 1.4.0
+   BME280@~3.0.0
+```
+
+# Credits
+
+- Aircoookie for making WLED
+- Other usermod creators for example code (`sensors_to_mqtt` and `multi_relay` especially)
+- You, for reading this

usermods/Si7021_MQTT_HA/usermod_si7021_mqtt_ha.h

@@ -0,0 +1,236 @@
+#pragma once
+
+// this is remixed from usermod_v2_SensorsToMqtt.h (sensors_to_mqtt usermod)
+// and usermod_multi_relay.h (multi_relay usermod)
+
+#include "wled.h"
+#include <Adafruit_Si7021.h>
+#include <EnvironmentCalculations.h> // EnvironmentCalculations::HeatIndex(), ::DewPoint(), ::AbsoluteHumidity()
+
+Adafruit_Si7021 si7021;
+
+#ifdef ARDUINO_ARCH_ESP32 //ESP32 boards
+uint8_t SCL_PIN = 22;
+uint8_t SDA_PIN = 21;
+#else //ESP8266 boards
+uint8_t SCL_PIN = 5;
+uint8_t SDA_PIN = 4;
+#endif
+
+class Si7021_MQTT_HA : public Usermod
+{
+  private:
+    bool sensorInitialized = false;
+    bool mqttInitialized = false;
+    float sensorTemperature = 0;
+    float sensorHumidity = 0;
+    float sensorHeatIndex = 0;
+    float sensorDewPoint = 0;
+    float sensorAbsoluteHumidity= 0;
+    String mqttTemperatureTopic = "";
+    String mqttHumidityTopic = "";
+    String mqttHeatIndexTopic = "";
+    String mqttDewPointTopic = "";
+    String mqttAbsoluteHumidityTopic = "";
+    unsigned long nextMeasure = 0;
+    bool enabled = false;
+    bool haAutoDiscovery = true;
+    bool sendAdditionalSensors = true;
+
+    // strings to reduce flash memory usage (used more than twice)
+    static const char _name[];
+    static const char _enabled[];
+    static const char _sendAdditionalSensors[];
+    static const char _haAutoDiscovery[];
+
+    void _initializeSensor()
+    {
+      sensorInitialized = si7021.begin();
+      Serial.printf("Si7021_MQTT_HA: sensorInitialized = %d\n", sensorInitialized);
+    }
+
+    void _initializeMqtt()
+    {
+      mqttTemperatureTopic = String(mqttDeviceTopic) + "/si7021_temperature";
+      mqttHumidityTopic = String(mqttDeviceTopic) + "/si7021_humidity";
+      mqttHeatIndexTopic = String(mqttDeviceTopic) + "/si7021_heat_index";
+      mqttDewPointTopic = String(mqttDeviceTopic) + "/si7021_dew_point";
+      mqttAbsoluteHumidityTopic = String(mqttDeviceTopic) + "/si7021_absolute_humidity";
+
+      // Update and publish sensor data
+      _updateSensorData();
+      _publishSensorData();
+
+      if (haAutoDiscovery) {
+        _publishHAMqttSensor("temperature", "Temperature", mqttTemperatureTopic, "temperature", "°C");
+        _publishHAMqttSensor("humidity", "Humidity", mqttHumidityTopic, "humidity", "%");
+        if (sendAdditionalSensors) {
+          _publishHAMqttSensor("heat_index", "Heat Index", mqttHeatIndexTopic, "temperature", "°C");
+          _publishHAMqttSensor("dew_point", "Dew Point", mqttDewPointTopic, "", "°C");
+          _publishHAMqttSensor("absolute_humidity", "Absolute Humidity", mqttAbsoluteHumidityTopic, "", "g/m³");
+        }
+      }
+      
+      mqttInitialized = true;
+    }
+
+    void _publishHAMqttSensor(
+      const String &name, 
+      const String &friendly_name, 
+      const String &state_topic, 
+      const String &deviceClass, 
+      const String &unitOfMeasurement)
+    {
+      if (WLED_MQTT_CONNECTED) {
+        String topic = String("homeassistant/sensor/") + mqttClientID + "/" + name + "/config";
+
+        StaticJsonDocument<300> doc;
+
+        doc["name"] = String(serverDescription) + " " + friendly_name;
+        doc["state_topic"] = state_topic;
+        doc["unique_id"] = String(mqttClientID) + name;
+        if (unitOfMeasurement != "")
+          doc["unit_of_measurement"] = unitOfMeasurement;
+        if (deviceClass != "")
+          doc["device_class"] = deviceClass;
+        doc["expire_after"] = 1800;
+
+        JsonObject device = doc.createNestedObject("device"); // attach the sensor to the same device
+        device["name"] = String(serverDescription);
+        device["model"] = "WLED";
+        device["manufacturer"] = "Aircoookie";
+        device["identifiers"] = String("wled-") + String(serverDescription);
+        device["sw_version"] = VERSION;
+
+        String payload;
+        serializeJson(doc, payload);
+
+        mqtt->publish(topic.c_str(), 0, true, payload.c_str());
+      }
+    }
+
+    void _updateSensorData()
+    {
+      sensorTemperature = si7021.readTemperature();
+      sensorHumidity = si7021.readHumidity();
+
+      // Serial.print("Si7021_MQTT_HA: Temperature: ");
+      // Serial.print(sensorTemperature, 2);
+      // Serial.print("\tHumidity: ");
+      // Serial.print(sensorHumidity, 2);
+
+      if (sendAdditionalSensors) {
+        EnvironmentCalculations::TempUnit envTempUnit(EnvironmentCalculations::TempUnit_Celsius);
+        sensorHeatIndex = EnvironmentCalculations::HeatIndex(sensorTemperature, sensorHumidity, envTempUnit);
+        sensorDewPoint = EnvironmentCalculations::DewPoint(sensorTemperature, sensorHumidity, envTempUnit);
+        sensorAbsoluteHumidity = EnvironmentCalculations::AbsoluteHumidity(sensorTemperature, sensorHumidity, envTempUnit);
+
+        // Serial.print("\tHeat Index: ");
+        // Serial.print(sensorHeatIndex, 2);
+        // Serial.print("\tDew Point: ");
+        // Serial.print(sensorDewPoint, 2);
+        // Serial.print("\tAbsolute Humidity: ");
+        // Serial.println(sensorAbsoluteHumidity, 2);
+      }
+      // else
+      //   Serial.println("");
+    }
+
+    void _publishSensorData()
+    {
+      if (WLED_MQTT_CONNECTED) {
+        mqtt->publish(mqttTemperatureTopic.c_str(), 0, false, String(sensorTemperature).c_str());
+        mqtt->publish(mqttHumidityTopic.c_str(), 0, false, String(sensorHumidity).c_str());
+        if (sendAdditionalSensors) {
+          mqtt->publish(mqttHeatIndexTopic.c_str(), 0, false, String(sensorHeatIndex).c_str());
+          mqtt->publish(mqttDewPointTopic.c_str(), 0, false, String(sensorDewPoint).c_str());
+          mqtt->publish(mqttAbsoluteHumidityTopic.c_str(), 0, false, String(sensorAbsoluteHumidity).c_str());
+        }
+      }
+    }
+
+  public:
+    void addToConfig(JsonObject& root)
+    {
+      JsonObject top = root.createNestedObject(FPSTR(_name));
+      
+      top[FPSTR(_enabled)] = enabled;
+      top[FPSTR(_sendAdditionalSensors)] = sendAdditionalSensors;
+      top[FPSTR(_haAutoDiscovery)] = haAutoDiscovery;
+    }
+
+    bool readFromConfig(JsonObject& root)
+    {
+      JsonObject top = root[FPSTR(_name)];
+      
+      bool configComplete = !top.isNull();
+      configComplete &= getJsonValue(top[FPSTR(_enabled)], enabled);
+      configComplete &= getJsonValue(top[FPSTR(_sendAdditionalSensors)], sendAdditionalSensors);
+      configComplete &= getJsonValue(top[FPSTR(_haAutoDiscovery)], haAutoDiscovery);
+
+      return configComplete;
+    }
+
+    void onMqttConnect(bool sessionPresent) {
+      if (mqttDeviceTopic[0] != 0)
+        _initializeMqtt();
+    }
+
+    void setup()
+    {
+      if (enabled) {
+        Serial.println("Si7021_MQTT_HA: Starting!");
+        Wire.begin(SDA_PIN, SCL_PIN);
+        Serial.println("Si7021_MQTT_HA: Initializing sensors.. ");
+        _initializeSensor();
+      }
+    }
+
+    // gets called every time WiFi is (re-)connected.
+    void connected()
+    {
+      nextMeasure = millis() + 5000; // Schedule next measure in 5 seconds
+    }
+
+    void loop()
+    {
+      yield();
+      if (!enabled || strip.isUpdating()) return; // !sensorFound || 
+
+      unsigned long tempTimer = millis();
+
+      if (tempTimer > nextMeasure) {
+        nextMeasure = tempTimer + 60000; // Schedule next measure in 60 seconds
+
+        if (!sensorInitialized) {
+          Serial.println("Si7021_MQTT_HA: Error! Sensors not initialized in loop()!");
+          _initializeSensor();
+          return; // lets try again next loop
+        }
+
+        if (WLED_MQTT_CONNECTED) {
+          if (!mqttInitialized)
+            _initializeMqtt();
+
+          // Update and publish sensor data
+          _updateSensorData();
+          _publishSensorData();
+        }
+        else {
+          Serial.println("Si7021_MQTT_HA: Missing MQTT connection. Not publishing data");
+          mqttInitialized = false;
+        }
+      }
+    }
+    
+    uint16_t getId()
+    {
+      return USERMOD_ID_SI7021_MQTT_HA;
+    }
+};
+
+// strings to reduce flash memory usage (used more than twice)
+const char Si7021_MQTT_HA::_name[]                   PROGMEM = "Si7021 MQTT (Home Assistant)";
+const char Si7021_MQTT_HA::_enabled[]                PROGMEM = "enabled";
+const char Si7021_MQTT_HA::_sendAdditionalSensors[]  PROGMEM = "Send Dew Point, Abs. Humidity and Heat Index";
+const char Si7021_MQTT_HA::_haAutoDiscovery[]        PROGMEM = "Home Assistant MQTT Auto-Discovery";

wled00/const.h

@@ -75,6 +75,7 @@
 #define USERMOD_ID_WIZLIGHTS             26     //Usermod "wizlights.h"
 #define USERMOD_ID_WORDCLOCK             27     //Usermod "usermod_v2_word_clock.h"
 #define USERMOD_ID_MY9291                28     //Usermod "usermod_MY9291.h"
+#define USERMOD_ID_SI7021_MQTT_HA        29     //Usermod "usermod_si7021_mqtt_ha.h"
 
 //Access point behavior
 #define AP_BEHAVIOR_BOOT_NO_CONN          0     //Open AP when no connection after boot

wled00/usermods_list.cpp

@@ -124,6 +124,10 @@
 #include "../usermods/MY9291/usermode_MY9291.h"
 #endif
 
+#ifdef USERMOD_SI7021_MQTT_HA
+#include "../usermods/Si7021_MQTT_HA/usermod_si7021_mqtt_ha.h"
+#endif
+
 void registerUsermods()
 {
 /*
@@ -235,4 +239,8 @@ void registerUsermods()
   #ifdef USERMOD_MY9291
   usermods.add(new MY9291Usermod());
   #endif
+  
+  #ifdef USERMOD_SI7021_MQTT_HA
+  usermods.add(new Si7021_MQTT_HA());
+  #endif
 }