完成功能:1串口接收数据,PC接收到来自单片机的数据2串口发送数据到单片机控制led灯，同时将发送的数据返回 -Complete feature: a serial port to receive data, the PC receives the data from the microcontroller serial port to send data to the microcontroller to control the led lights, while the data sen

51开发板原理图，涵盖LED模块，4*4键盘模块，数码管显示模块，串口模块，放大模块。