Using the LEGO MINDSTORMS NXT brick, the light sensor is able to sense light or dark as well as light intensity in a room. It is also able to measure light intensity in colours (grey scale sorting).

Suggestions for use:

You can use the Lego Mindstorms NXT Light Sensor to make a burglar alarm robot: when an intruder turns on the light in your room the robot can react to defend your property. You can also use the Light Sensor to make a line-following robot or a robot that can sort things by color.

You will need a connector cable, which is included in the 9797 Base Set.