sim300的源程序，可以发短信，；连接gprs网络，可以参考-sim300 of the source, you can send text messages connection gprs network, you can refer to

sin900a模块与51单片机连接，51单片机控制gprs模块，与服务器通信-Sin900a module and 51 single-chip connection, 51 single-chip control gprs module, and server communication