本次设计就是来完成由上位机通过串口控制来实现，以发光二极管的发光状态模拟开关电路的通断，用上位机的DOS命令对其进行控制。并用LED屏显示程序的传输。(This design is completed by the host computer through serial port control. The LED switch's luminous state is used to simulate the on-off of the switch circuit, and the upper