images are CC BY-NC-SA 3.0
Description: The Brightness Cubelet has an analog photocell that responds to varying light conditions and detects the amount of light hitting it's sensor. Expect values near zero in a dark room, and values near one when the sensor is in front of a bright light.
Cubelets are magnetic blocks that can be snapped together to make an endless variety of robots. You can build robots that drive around on a tabletop, respond to light, sound, and temperature, and have surprisingly lifelike behavior. But instead of programming that behavior, you snap the cubelets together and watch the behavior emerge like with a flock of birds or a swarm of bees.
Note: Cubelets require a special battery and charger. You will need to purchase the charger separately.