Hello,
I recently bought a Sim 900a module and have been really struggling with it.
When I supply it with power (5v 2amp) or just with the arduino, the red power Light turns on and I am greeted with 4 fast flashes of the signal light before it turns off again. It never flashes every second or every 3 seconds. It seems to randomly come on About every couple of minutes.
I have a SIM card in it which works perfectly in my phone but not in that module.
The AT commands are not working mostly and when I do get an understandable response it is always saying service, 0.
I have tried all different board rates but nothing is working.
I do live in Australia and I have heard it is made with the intention to be used in Asia but surely it would at least flash the signal light even without a SIM card.
Thank you in advance,
Kind regards,
Sam
I'm sure the SIM900a is 2G, and I don't think there is any 2G network left here, hence the service, 0. The intermittent operation is probably evidence of it sniffing around, futilely. Your SIM is fine, your shield isn't.
Thank you for your advice. I am really appreciative. I am going to hassle you even more.
Now I know that won’t ever work, I need a 3G module. Do you know of any extremly low cost ones
I'm afraid not. I have not been following this too closely but, from the best I can tell, 3G shields are more than twice the price of a SIM900a.
Edit
Things change all the time. Check this out
it's actually a local supplier. I'm amazed....