The GPRS Shield is based on SIM900 module from SIMCOM and compatible with Aduino and its clones. The GPRS Shield provides you a way to communicate using the GSM cell phone network. The shield allows you to achieve SMS, MMS, GPRS and Audio via UART by sending AT commands (GSM 07.07 ,07.05 and SIMCOM enhanced AT Commands). The shield also has the 12 GPIOs, 2 PWMs and an ADC of the SIM900 module(They are all 2V8 logic) present onboard.
SIM900 Arduino Shield connect to arduino by using Serial port, you can choose connect sim900 to arduino hardware serial port, or using any two IO pins as software serial port to communication. This is can be done by changing the jumper.
