我在项目开发过程中搜集的各种NMEA协议文档，用于开发各种与GPS相关的项目。-I am in the project development process to collect a variety of NMEA protocol document for the development of a variety of GPS-related projects.

在Linux上实现GPRS的功能，实现短信功能，对研究GPRS有帮助，基于sim3-GPRS in Linux to achieve the functions of SMS function, GPRS helpful for research, based on sim300