51单片机控制步进电机，其中没有使用按键，而是使用定时器控制步进电机正反转和停止，明白易懂，是进行其他复杂编程的良好基础-51 SCM stepper motor control, which does not use keys, but the use of a timer to control the stepper motor reversing and stopping, easy to understand, is a good basis for other complex prog