PING))) ultrasonic distance sensor module
The PING))) ultrasonic sensor provides a low-cost and easy method of distance measurement. This sensor is perfect for any number of applications that require you to perform measurements between moving or stationary objects. Robotics applications are popular but you will also find it to be useful in security systems or as an infrared replacement. The PING))) sensor measures distance using sonar: an ultrasonic (well above human hearing) pulse is transmitted from the unit and distance-to-target is determined by measuring the time required for the echo return. Output from the PING))) sensor is a variable-width pulse that corresponds to the distance to the target.