基于SIM908和KL25的浮动车定位器设计

Design of Probe Vehicle Tracker Based on SIM908 and KL25

摘要:

为便于实时交通信息数据采集,设计并实现了一种基于SIM908模块和KL25微控制器的浮动车定位器,将GPS信息通过GPRS网络实时传输至服务器端；利用SIM908已有的射频连接器和内部集成的电源管理电路,减小了定位器的尺寸；利用SIM908和KL25的低功耗特性,增强了定位器的续航能力；微控制器的软件设计基于FreeRTOS实时操作系统,解析SIM908输出的基于NMEA协议的GPS报文,并使用AT指令控制SIM908与远程服务器基于TCP协议进行数据传输；实际测试结果表明,该定位器具有较高的稳定性和定位精度,并兼具便携性和长时间续航能力。

Abstract:

A probe vehicle tracker which could send GPS information to server through GPRS network in real time has been built based on SIM908 module and KL25 microcontroller to gather live transportation information. The RF connector in the module side and the power management circuit in the module are taken full advantage of to reduce the tracker’s size while the tracker features long battery life with the low power consumption feature of SIM908 and KL25. With the FreeRTOS real-time operation system, the TCP-based data transportation between SIM908 and remote server by using AT commands has been developed as well as parsing the GPS reports in NMEA format from the module. Practical test result indicates that the portable tracker works stably with high positioning accuracy and long battery life.