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VEML6040 RGBW Color Sensor

The veml6040 sensor platform allows you to use the Vishay VEML6040 RGBW color sensor with ESPHome. It reports the red, green, blue and white channels, illuminance and correlated color temperature. Communication with the device is over I²C, which must be present in your configuration.

The sensor measures continuously. Each channel is a 16-bit count, so it ranges from 0 to 65535. Illuminance is calculated from the green channel. Color temperature uses the formula from the Vishay application note “Designing the VEML6040 into an Application”. Both values are approximate without calibration for your light source and enclosure.

A red, green or blue channel that reaches 65535 is saturated, and a warning is logged. The white channel is not checked, so a white reading of 65535 comes with no warning. If the green channel is saturated, illuminance is reported as unknown. If any of the red, green or blue channels is saturated, color temperature is reported as unknown. A saturated red or blue channel does not affect illuminance, so a valid lux reading can appear next to an unknown color temperature. Use a shorter integration_time in bright light.

# Example configuration entry
sensor:
  - platform: veml6040
    red_channel:
      name: "Red Channel"
    green_channel:
      name: "Green Channel"
    blue_channel:
      name: "Blue Channel"
    white_channel:
      name: "White Channel"
    illuminance:
      name: "Illuminance"
    color_temperature:
      name: "Color Temperature"

Configuration Variables

Section titled “Configuration Variables”

  • red_channel (Optional): Raw count of the red channel. All options from Sensor.

  • green_channel (Optional): Raw count of the green channel. All options from Sensor.

  • blue_channel (Optional): Raw count of the blue channel. All options from Sensor.

  • white_channel (Optional): Raw count of the white channel. All options from Sensor.

  • illuminance (Optional): Illuminance in lux. All options from Sensor.

  • color_temperature (Optional): Correlated color temperature in kelvin. All options from Sensor.

  • integration_time (Optional, Time): The time the device uses for each measurement. Longer times give more resolution in low light, but the sensor saturates at a lower light level. It must be one of:

    Integration timeLux per countMaximum lux
    40ms0.2516816496
    80ms0.125848248
    160ms (default)0.062924124
    320ms0.031462062
    640ms0.015731031
    1280ms0.007865515.4

  • glass_attenuation_factor (Optional, float): Corrects the illuminance for light lost when the sensor is behind glass or another cover. The value is the inverse of the cover’s transmission; for example, a cover that passes 50% of the light needs a factor of 2. Defaults to 1.0 (no cover). Must be at least 1.0. It does not affect color temperature; use color_temperature_offset for that.

  • color_temperature_offset (Optional, float): The offset in the color temperature formula CCT = 4278.6 × ((R − B) / G + offset) ^ −1.2455. Vishay gives 0.5 for a sensor in open air and notes that the value changes behind cover glass. To tune it, compare the reported color temperature with a reference meter or a light source of known color temperature, and adjust the offset until they match. Defaults to 0.5.

  • update_interval (Optional, Time): The interval to check the sensor. Defaults to 60s.

  • address (Optional, int): The I²C address of the sensor. Defaults to 0x10.

  • i2c_id (Optional, ID): The ID of the I²C bus to use, if you have more than one.

See Also

Section titled “See Also”