说明：  按钮分别接5，6（对应电机正反转），电位器接A0接口（调速用），DI接10，PU接11，EN可不接（我已经把它设置为全程关闭了），可以实现步进电机的基本控制。
(The buttons are respectively connected with 5 and 6 (corresponding to the positive and negative rotation of the motor), the potentiometer is connected with A0 interface (for speed regulation), the Di is connected with 10, the Pu is connected with 11, and the en is not connected (I have set it to be closed in the whole process), which can realize the basic control of the stepping motor.)