Si7021 to MQTT (with Home Assistant Auto Discovery) usermod

This usermod implements support for Si7021 I²C temperature and humidity sensors.

As of this writing, the sensor data will not be shown on the WLED UI, but it is published via MQTT to WLED's "built-in" MQTT device topic.

temperature: $mqttDeviceTopic/si7021_temperature
humidity: $mqttDeviceTopic/si7021_humidity

The following sensors can also 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/sent 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