单片机控制步进电机的上位机调试程序，上位机发送指令，下位机执行-Stepper motor microcontroller debugger PC, PC to send commands, the implementation of the next crew

通过串口实现VB程序和单片机的通讯，并实时控制步进电机的转速和方向。-VB program through the serial port and single-chip communication, and real-time control of the stepper motor speed and direction.