Pololu Digital Distance Sensor, 15cm

This small lidar-based distance sensor detects the presence objects within 15 cm (6″). It has a single digital output that drives low when an object is being detected; otherwise, it is high. It works over an input voltage range of 3.0 V to 5.5 V, and the 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards.

Note: A newer version of this sensor is now available.