> For the complete documentation index, see [llms.txt](https://learn.arduinosa.co.za/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://learn.arduinosa.co.za/sensor-kits/37-in-1-sensor-kit/photoresistor.md).

# Photoresistor

![](/files/-MS2OnavNZU--3HXSzej)

LDR (Light Dependant Resistor). Dark resistance >20M Ohm, light <80 Ohm. The two outer pins connect to the LDR. A fixed 10 K ohm resistor connected between the middle pin and the ‘S’ pin is included on the module. This simplifies the building of a measurement bridge circuit.