说明：  该程序可以驱动常见的两相4步的小型步进电机并且可以通过按键控制电机加速减速暂停正反转。并且将相关信息显示在数码管上。
(The program can drive the common four-step two-phase stepper motors and can be a small button to control motor speed reducer through the suspension of positive inversion. And relevant information will be displayed in the digital pipe.)