用4个开关设置发送的数据，然后通过串口将数据发回来~~ 如果接收的数据和发送的数据一样则两个数码管显示的数据将会一样-Switch with four settings to send data, then send back the data through the serial port ~ ~ If you receive data and send the data as the two digital display of the data will be the same as