由步进电机实验，设计一个控制步进电机实验电路，能够完成步进电机调速控制，同时检测8种不同开关状态，实现7层楼的电梯运行过程控制。-By a stepping motor experiment, experimental design a stepper motor control circuit, to complete the stepper motor speed control, and 8 different switch status detection, to achieve 7 f