说明：  基于单片机自行车测速系统；速度里程表由信号预处理电路、AT89C51单片机、数码管显示电路、串口数据存储电路和系统软件组成。
(Velocity measurement system based on MCU bicycle speed odometer by the signal preprocessing circuit, AT89C51 microcontroller, digital display circuit, serial data storage circuit and system software.)