sim900 (n95dg) arduino mega ADK

Official Hardware Retired GSM Shield
1

HI
i have recently brought the arduino mega ADK and sim900 gsm Module from maplin.
i have tried the example gsm_scanner just to test if the module is working. the gsm module seems to work fine with the network light flashing every so often, just the module is not communicating with the arduino board all i get is "GSM networks scanner"

i have powered it with a 12v power supply able to supply 2 amps.

the issue i have, i dont know where to connect the serial
i have bent pin 2 and connected the pin to pin 10 as i have read here:

but this has not worked for me,

i have also set the jumpers to software serial and connected the software serial pins to mega adk pins 18,19 but this has not worked for me.

thank you in advance if anyone can help

2

The thing that stands out its your 12v supply.

The Maplin / Linksprite gsm shield specifies a 5v input.

While I cannot find the exact schematic for that board and its regulators there is a chance you may have damaged it.

Also 12V is about the maximum ideal you should feed into the mega if you intend to do that, 9v much better as the onboard regulator will not get overheat.

Have you checked that your psu is giiving out a true 12dc , many cheap wall plugs give out much higher.

Have got a sim 900 shield but only run it on the Uno, have a standard mega but not tried that yet, will try it with the Unos software later.

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3

Should have added that you can , for testing purposes, run the shield from the megas internal 5v power source.

Move slider switch by the jack socket to the 'internal' power position and plug the shield in.

You can easily test it out with the AT commands and send out SMS this way.