该程序为UART程序。 通信协议为： 1.假如接收到A或a，则向电脑发送0到9 2.假如收到8，则停止发送数据 3.否则轰鸣器报警。 -The program for the UART program. The communication protocol is: 1. Received A or a computer to send 0-9 2. Received eight, stop sending data. Otherwise roar Alarm.