Skip to content


BH1750 usermod

This usermod will read from an ambient light sensor like the BH1750. The luminance is displayed in both the Info section of the web UI, as well as published to the /luminance MQTT topic if enabled.


  • Libraries
  • claws/BH1750 @^1.2.0
  • This must be added under lib_deps in your platformio.ini (or platformio_override.ini).
  • Data is published over MQTT - make sure you've enabled the MQTT sync interface.


To enable, compile with USERMOD_BH1750 defined (e.g. in platformio_override.ini)

extends = env:d1_mini
build_flags =
    -D USERMOD_BH1750
lib_deps = 
    claws/BH1750 @ ^1.2.0

Configuration Options

The following settings can be set at compile-time but are configurable on the usermod menu (except First Measurement time): * USERMOD_BH1750_MAX_MEASUREMENT_INTERVAL - the max number of milliseconds between measurements, defaults to 10000ms * USERMOD_BH1750_MIN_MEASUREMENT_INTERVAL - the min number of milliseconds between measurements, defaults to 500ms * USERMOD_BH1750_OFFSET_VALUE - the offset value to report on, defaults to 1 * USERMOD_BH1750_FIRST_MEASUREMENT_AT - the number of milliseconds after boot to take first measurement, defaults to 10000 ms

In addition, the Usermod screen allows you to: - enable/disable the usermod - Enable Home Assistant Discovery of usermod - Configure the SCL/SDA pins


The following method is available to interact with the usermod from other code modules: - getIlluminance read the brightness from the sensor

Change Log

Jul 2022 - Added Home Assistant Discovery - Implemented PinManager to register pins - Made pins configurable in usermod menu - Added API call to read luminance from other modules - Enhanced info-screen outputs - Updated

Fork specific info