直流电机调速模块采用模拟出租车的速度，通过模数转换为S。

代码说明：

采用直流电机测速单元模拟出租车速度，通过A/D转换进行速度采样，利用单片机的定时器/计数器定时和计数，用LED数码管或LCD显示总价和时间，并通过键盘进行单价设定及时间显示，键盘功能自行定义。-DC Motor Speed modules using simulation taxi speed, through the A/D conversion speed of sampling, the use of single-chip timer/counter timing and counting, with LED digital tube or LCD display the total price and time, and through keyboard Price settings and time display, keyboard function on its own definition.