基于CPLD的超声波精密测距仪设计

his paper presents a high accuracy ultrasonic measuring distance based on CPLD design. It is mainly used to count the wave number by CPLD, a wavelength(coarse code) is divided into 256 equal elements, each element called the precision code, the sum of coarse and precision code is a wave number. Microcontroller controls sending, receiving, calculating the distance and the liquid crystal display. Compared with conventional ultrasonic ranging system, the design with high precision and repeatable, and can be eliminated the influence of temperature, pressure, humidity and other parameters on the system.