无公网 IP，使用花生壳内网映射实现外网数据传递到内网；基于2G DTU GPRS730 设备，连接到服务器；实现串口向服务器发送数据，接收服务器返回的数据；
Without public network IP, peanut shell intranet mapping is used to transfer data from external network to intranet; 2G DTU GPRS730 device is used to connect to the server; serial port is used to send data to the server and receive data returned by the server; (2019-02-27, Others, 600KB, 下载2次)