AT 指令通过GSM 串口发送到模块并接收返回指令。GPS 的控制指令也是

通过GSM 串口控制，GPS 串口只负责输出相应的GPS 信息.本文档时针对SIM908的AT指令集做解析。-Serial port to send AT commands to the module via the GSM and receive return instructions. GPS control command is serial control via GSM, GPS serial output is only responsible for the corresponding GPS information in this document for the SIM908 AT command set to do parsing.