在两块单片机之间，通过串口通信机制，控制步进电机转动和停止。当指拨开关接地时，电机停止；当指拨开关接+5v电源时，电机转动。-Between the two single-chip, through the serial communication mechanisms to control the stepper motor rotates and stops. When the DIP switch is grounded, the motor stops When the DIP swi