Here are case studies of two such projects. A stepping motor rotates the rangefinder, giving 360 coverage. The computer paints a graphic display of its surroundings with resolution better than 0.1 inch. This project combines motor control with measurement of time intervals. The rangefinder emits a brief pulse of high frequency sound.
Any object hit by the sound produces an echo.
The distance to the object is measured by very accurately timing from the pulse to the echo. The rangefinder is made up of two parts, a transducer and a driver board. The transducer acts as both a speaker and a microphone. It emits the sound pulse and listens for the echo. The driver board provides the high voltages required to run the transducer, sensitive amplifiers for the echo detection, and control logic.