The light sensor module provides an analog output for measuring and triggering dependant on surround light level. All you need to connect it to your Arduino or compatible board is GND, 5V, and one analog input. On a 3.3V microcontroller VCC should be connected to 3.3V instead of 5V. Accepts any power source (VCC) between 3.0 and 5.5V DC. Output voltage will vary between 0V and slightly less than VCC.