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Sim900 Arduino shield
Posted: Fri Oct 21, 2016 6:23 am
by nerdmedic
I have a Sim900 Arduino shield but even with a known good SIM, I am not able to get it working and it doesn't appear to initialize. Do anyone know of a good Arduino sketch that could be installed to help me troubleshoot and figure out why it will not connect to the GSM network? Or perhaps a good reference for the AT command set for the SIM900?
Re: Sim900 Arduino shield
Posted: Fri Oct 21, 2016 5:58 pm
by William
Re: Sim900 Arduino shield
Posted: Fri Oct 21, 2016 10:00 pm
by nerdmedic
No, unfortunately, the AT Command Manual didn't help because I cannot get to the point that I can query the module using the AT command set. I have tried both SoftSerial (on ports 8 and 7) and hard serial on 1 and 2 and I have not been able to communicate with the module. The only return I get is an error code that the module is not ready... which would make sense if I don't have the communications pins right.
What would probably be most helpful would be a schematic of the shield so I can see how the serial pins to/from the module are routed. At this point, the only clues I have are from the screenprinting on the board and they have not been shown to be accurate at this point.
Nerdmedic
Re: Sim900 Arduino shield
Posted: Sat Oct 22, 2016 1:46 pm
by William
I'm not sure which one you've bought of the two shields:
- QQ截图20161022134356.jpg (92.47 KiB) Viewed 6580 times
And don't know if it helps:
http://www.geeetech.com/Documents/GPRSshield_sch.pdf
Re: Sim900 Arduino shield
Posted: Sat Oct 22, 2016 4:48 pm
by nerdmedic
In the picture provided, the one I have is on the right.
Re: Sim900 Arduino shield
Posted: Mon Oct 24, 2016 11:48 am
by William
OK,the schematic i posted belongs to the right one.