【摘要】 出租车计价器是单片机的一种典型应用。基于单片机的计价器是由单片机和外部电路组成。利用AT89C51的全双工串行口进行通信,其外接显示电路由74LS614和共阳极数码管构成,实现了扩展并行I/O接口的功能,可以实现单价,起步价,返程价,郊区价,夜间价,低速价,显示和修改时间。更多还原

【Abstract】 Taxi computation system is a kind of classic application of chip microprocessors,which is composed of chip microprocessors and outer electro circuit,and communicates with the use of AT89C51 serial interface. The outside display electro circuit of taxi computation system is consisted of 74LS614 and anode numerical display tube,which actualize the function of expanding I/O parallel interface and the function of displaying for unit price,starting price,returning price,countryside price,night price,low-speed price and time revising.Through connecting P0 with outer electro circuit about phonetic quotation,AT89C51 can actualize the function of phonetic quotation.更多还原