SparkFun Forums

[chaost]

Hello there,

I am having an issue with this shield. It does not seem to recognise any SIM cards. I have tried 4 of them (3 pay-as-you-go and 1 contract).

I keep getting +SIND: 0

All of the SIM cards work in mobile phones and are not PIN protected.

Here is a screen shot of the terminal output:



And here is a picture of the setup (in case anybody can see any glaringly obvious hiccup! )



And before anyone says it - I know it is recommended to power the board directly with 9v 2 amp. I have tried this too but it makes no difference.

The GSM band is set to 4 - which is apparently UK. I have tried 0 and 5 too. No difference.

I have done a thorough google search and read other posts - none seem to be about this problem or a solution.

Needless to say, any help / tips would be gratefully appreciated!

[maokh]

+SIND must be some annoying unsolicited response.

try a AT+CPIN? and see what it says.

then try an AT+CREG?

It will take the device a few seconds to register, but very strange.

You can also try to listen to the audio and perform a simple dial operation for a non working number: ATD611; and see if you can determine if the call is being denied due to a particular reason.

Do the SIMs work fine in a normal cell phone?

[chaost]

Thanks for the reply maokh.

AT+CPIN? returns CME ERROR: 10 - which i believe to be SIM NOT INSERTED.

AT+CREG? returns +CREG: 0,3 - which seems to be network denied or something but probably due to SIM not being recognised in the first place?

The SIM's do work in a normal cell phone.

I have ordered up another board to eliminate the possibility of a duff board / SM5100 chip. No way i'm giving up on this so any further suggestions welcomed! 8)

[maokh]

I haven't used the SM5100B in particular, so I do not know if the module has any quirks, but the only thing that has caused me trouble in the past would be issues with the capacitors between the GSM module and the SIM, SIM socket switch failure or failure to permanently ground the SIMIN line, or some sort of physical issue with the sim socket (including a time when a fab shop we used accidentally put it on backwards)

On the more rarer case, the SIM card may have some sort of unsupported architecture (pre-paid) or voltage incompatibility, but nearly any GSM module today supports both voltages.

If the new shield works fine, id suggest testing the capacitors. Otherwise, it could be a bad module?

[chaost]

New shield arrived this morning....

Had it working inside of 10 minutes (despite having to reconfigure baud rate to 9600 ).

So definitely a faulty shield or chip on the original shield it seems.

Thanks for your suggestions maokh!

[tspedaliere]

Hi Chaost,

Which GSM Shield did you end up using after?

Thanks
Tony

[chaost]

Hi Tony - I ordered a replacement of the same shield. It was just a fault with that particular one. I have used another 3 since then and they all work fine.
Good luck!