本电路以89S51 单片机为中心、附加A44E 霍尔传感器测距，实现对出租车计价统计，

采用AT24C02 实现在系统掉电的时候保存单价和系统时间等信息，输出采用8 段数码显示

管。本电路设计的计价器不但能实现基本的计价，而且还能根据白天、黑夜、中途等待来调

节单价，同时在不计价的时候还能作为时钟为司机同志提供方便。-The circuit 89S51 microcontroller as the center, additional A44E Hall sensor ranging realize the taxi meter statistics, using AT24C02 achieve price and save time and other information systems in the system is powered down when the output 8-segment LED display tube. The circuit design of the meter can not only achieve the basic valuation, but also according to day and night, waiting to adjust the price midway while not denominated as the clock time can provide convenience for drivers comrades.