I recently purchased a GSM shield for my project. For the GSM shield i required a SIM card, which i bought from one of the service providers in the area (Virgin Mobile). Once I placed the SIM card into the SIM holder of the GSM shield and tested the connection, the "Network" LED indicator showed that their was SIM card detected or network connectivity.
I am new to using the GSM shield and not sure why this is happening. Is it due to the network provider? a CDMA vs GSM issue? the power supply to the GSM shield? Any help would be appreciated. Thanks.
The SIM may be locked to Virgin Mobile.
Where can I purchase an unlocked SIM?
I ran into this problem. What shield are you using?
I bought the geetech sim900 and tracphone sim. I replaced both. I got the Arduino official GSM shield, and then I bought a tmobile prepaid sim. It has to be the GSM band.
I think it likely has to do with your sim card. Get a different one that works on the GSM network and has data. Tracphone did not work (blinks rapidly) but then I went to tmobile and did not pair it with a phone and it worked.
If you are in the UK then a Tesco 2g/3g sim works fine in my board; no monthly limits/top ups needed.
You theoretically need a psu capable of 2A but thats generally only for a short time.
For my use, a standard 1A regulator with a 2200uf or greater capacitor seems to be fine.
Any more questions - then mention your make of board.