GPRS Shield v1.2 : Power supply selection


I m using gprs/gsm shield v1.2.

How can I select power supply : usb or external ?

There is no switch on the shield


Please, help me !

May I plug external power (5v) on my shield when it is plugged on my seeeduino Mega ?


Hi, you can download this attachment to see the schematic

You can select a board or external power (no more than 6v,5v is best),and if you plug your GPRS into a board and connect a external power to GPRS at the same time , your GPRS just would be powered by external power.