TinkerKit - LDR Sensor

The LDR (or Light Dependant Resistor, or Photoresistor) is a variable resistor. Light falling on the sensor reduces its resistance.

Output: This module emits a voltage of 5 V when the sensor receives no light (the circuit is open) and a voltage of 0 V when exposed to bright light (the circuit is closed). A green LED indicates that the module is correctly powered and a yellow LED changes brightness according to the light intensity.