Send Receive SMS & Call with SIM900 GPRS Shield & Arduino

Development Tools IDE 1.x
1

We have encountered the error ouf our Sim Card not being connected to cellular network according to the Arduino GPRS Shield. We have tested using the Sim Card with phones and it works, so we really have no idea what to do. It might be because we use an Arduino Uno as our power supply, but it seems to power the shield well as far as we can see. Thanks beforehand for the help.

The NetLight LED light turns on and off at a rate off 800ms which can have something to do with the error.

"64ms on, 800ms off: The SIM900 chip is running but not registered to the cellular network yet."

2

It might be because we use an Arduino Uno as our power supply

You are right, modems are very power hungry so you should use an external power source to supply it.
Your SIM 900 board should have an external power source.Use it