LIGHT is a light intensity sensor unit with an adjustable photo-resistor。

A photo-resistor is a light-controlled variable resistor. The resistance of a photo-resistor decreases with increasing incident light intensity and vice versa. The sensor exhibits photoconductivity which make it possible to detect the light varies based on voltage and use an AD (Analog to digital converter) to convert the digital data.

We added some extra work to strengthen the circuit, a Dual Differential Comparators LM393, compares the differential voltage between the photo-resistor and the varistor. It could offer larger and accuracy range of light intensity.


Resources Parameters
Product Size 32mm × 24mm × 8mm
Package Size 67mm × 53mm × 12mm
Product Weight 4g
Package Weight 17g

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UIFlow Blocks

  • get analog value
  • get digital value


  • Light_UNIT Demo

  • Light_UNIT Tutorial


Question: What is the difference between a digital ambient light sensor and a photointensity detection sensor? (Can the brightness of the computer monitor be measured?) )

  • -Illuminance:refers to how much light I get somewhere, and his unit of measurement is lux.
  • Brightness: The brightness of the recognition seen by the human eye. The unit of measurement is candela per square meter (cd/㎡).
  • Illuminance and brightness, one refers to how much light is obtained per unit area, and the other refers to how bright it looks per unit area.
  • Brightness is related to reflectivity, and the reflectivity of the palm of the hand is not the same, resulting in the difference between brightness and darkness. So the output of the digital ambient light sensor is the amount of light; The light source can be: incandescent lamp, fluorescent lamp, halogen lamp, white LED, sunlight;
  • The output of the photosensitive intensity detection sensor is the analog value of the brightness of the light; It can be divided into ultraviolet photoresistors, infrared photoresistors, visible photoresistors, here our sensor is visible light photointensity detection sensor。