Sonar Ranging is one of the most common forms of distance measurement used in Mobile Robotics and a variety of other applications. The principle is simple to understand, a speaker (Transducer) is used to emit a short burst of sound (Ping). The sound wave travels through the air and reflects off a target back to the Transducer (Echo). By measuring the Time of Flight between Ping and Echo detection, one can calculate the distance between the target and transudcer.
The Polaroid Corporation has developed the 6500 Sonar Ranging board and a series of Transducers which makes Sonar Ranging very simple. Interfacing to the 6500 Board is straigthtforward. The only hardware requirement is the ability to measure the Time of Flight which can usually be handled by a host Microcontroller or a simple clock and counter circuit. For application notes and source code see Tip #4 of the hints.
Maintained by John Loomis, last updated 14 Jan 1999