Infrared Sensor 10-80 cm - Sharp GP2Y0A21

This is the Sharp GP2Y0A21YK reflective IR distance sensor. It provides an analog voltage whose value is proportional to the distance of the detected object. The output voltage is 2,3 - 0,4V at 10 - 80 cm.

More information is available in the datasheet and on the website of Sparkfun.