利用PID算法实现直流电动机调速，可用16个按键精确设置转速值，并在8279数码管上显示当前转速、电压和设置转速。同时，系统还具有堵转判断功能。当电机在外力作用下被强行停止时，系统可自动停止运行，保护电路。-PID algorithm to achieve the DC motor speed control, 16 keys available to accurately set the speed value, speed, voltage and set the speed on the 8279 digital tube display. Meanwhile, the system also has the function of the stall judgment. When the motor was forced to stop under loads, the system can automatically stop running to protect the circuit.