SIM900 GSM / GPRS expansion board using SIM900 4 band GSM / GPRS module. Providing GSM / GPRS functionality extended to Arduino control board. After adding the expansion board, Arduino can send and receive short interest, as well as GPRS data communication connection.

Expansion board with a switch you can choose SIM900 or SIM900 debug serial port connection, if you select Debug port, serial port hardware must be practical Arduino to control, analog serial invalid. Farad capacitor provides power to the RTC module on board.Debug toggle switch, you can set the SIM900 the DEBUG port to connect to Arduino or connect to a PC via ATMEGA8U2 / FT232 Arduino on, carry on the debug

Automatic level 3.3V and 5V compatible with 3.3V or 5V can be adaptively control board, supports such 3.3V Chipkit leaf maple and other platform development board.

After SIM900 plug expansion board Arduino board, you must provide 9V / 2A DC power supply, or they may not work properly.

Quad-band GSM / GPRS 850/900/1800 / 1900MHz