基于长距离串口通信，由于串口只能短距离通信，但在多方面需要用到串口通信且距离较长，照成很多不便，所以在这里研究出一张长距离的串口通信方法。-Based on long-range serial communications, serial port only as short-distance communication, but many need to use serial communication and the distance is longer, according to a lot of inconvenience, so here come up with a long-distance serial communication method.