本文为DMA串口实验(DMA Serial TEST)，红牛开板测试正常，-This article for DMA Serial experiment (DMA Serial TEST), red bull open board TEST normal,

通讯检测.两个移位寄存器值进行对比，一致则通讯异常，红色灯亮，不一致则通讯正常，绿色灯亮-Communication detection. Two shift register value comparison consistent communications abnormal, red lights, inconsistent communication normally green lights

采集25扇门的开关状态,在面板上用红LED指示开,绿LED指示关,并把25扇门的开关状态用NMEA语句从RS422发送给上位机.-detect the 25pcs watertight door open/close status, and display the status of each door in panel, red LED mean open, green LED means close, meanwhile these information will be send out