Linux GPRS module problem

This is a hardware problem, but by my learning software to meet. It was awkward and tangled for a long time.

GPRS module If the SIM card is not plugged in, everything is OK after booting. Once the card is plugged in, it automatically shuts down after about 10 seconds. and print information on the serial port:

IIII

RDY

+cfun:1

+cpin:ready

+creg:0

+creg:2

Call ready

+creg:1

Started thinking it was a SIM card issue, and the SIM card is still the case. Then unplug the serial port, just plug in the power cord, can not see the serial port printing information, but the module is still on the boot about 10 seconds after the automatic shutdown. That's when I started to question the module itself. Before the module is very good, how can suddenly be broken? Analysis of the printed information, when the call is ready when the module will hang up, think of whether the power is too low power caused, and just before the power line can not find a random take a power cord, found that can be used directly. Then I found the original power cord, plugged in and sure enough! The original power cord is 9v--1a power cord, then I changed a 9v--2a can also be used.

Linux GPRS module problem