这是UART测试程序，下载本程序，将串口连接到 串口0 打开串口终端软件 将会显示串口0输出的信息 串口2输出开发板信息。-This is the UART test program, download this program that will open the serial port to connect to the serial port 0 serial 0 output terminal software information will be displayed 2 De