ABSTRACT
Using ultrasonic speed is easy to use, high reliability, not affected by climate condition the influence, etc. In different applications, the accuracy of ultrasonic speed system requirements are different, often use of ultrasonic speed of single-chip microcomputer control system, the error are generally in some cases cannot meet the requirement.
This paper introduces a kind of ultrasonic speed system based on AT89C51, including its work principle, the hardware composition and software flow. Hardware system by pulse launch circuit, receiving circuit, measuring temperature circuit and control circuit of the corresponding. Software part adopts singlechip C programming, mainly by, timer initialization, ultrasound subroutines, timer interrupt service procedure, external interrupt service procedure and LCD displays subroutines. At the same time, in order to improve the accuracy of ultrasonic speed, temperature sensors for environmental temperature detection, ultrasonic velocity. Tests, the system has high accuracy and strong adaptability.
Keywords: AT89C51, Ultrasonic speed, Temperature compensation
