Because the ultrasonic wave has the features, such as strong point, slow energy consumption and a long distance transmission in the medium, it always used for the distance measurement. Such as range finders and all level measurement can be achieved through the ultrasonic wave. Use of ultrasonic testing is often more rapid, convenient and simple terms, easy to achieve real-time control. It is a non-contact detection methods. Compared with other methods, it’s not influenced by light, color and other effects of the tested object. When the measured object in the dark, dusty, smoggy, toxic and other adverse circumstances, ultrasonic wave has a certain degree of adaptability.
This text has mainly described the principle and method of ultrasonic range-finder. The design uses STC89C52RC single-chip microcomputer as the main controller, the dynamic scanning method to achieve LED digital display, and single-chip timer to complete ultrasonic driving signals. Basing on introducing the function of ultrasonic ranging system, this thesis raises the overall composition of the system and also demonstrates the designed program including ranging system launch, receiving, testing, showed part.