Problem with GSM Network registration

Hello,

I have an arduino Leonardo and a GSM Shield (http://arduino.cc/en/Main/ArduinoGSMShield#.Uys6HnVJUoY) I am doing a very simple application that sends SMS however I'm having some problems with some SIM Cards.

My code is very simple... on the setup method I do:

 while(notConnected)
  {
    if(gsmAccess.begin()==GSM_READY)
    {
      notConnected = false;
    }
    else
    {
      delay(1000);
    }
  }

With some sim cards everything works perfectly... I can send SMS, do everything... no problems at all.. card registration takes a few seconds... But with some SIM Cards (a lot of other sim cards)... the method GSM.Begin never returns...

I enabled debugging to try and understand what was going on:

GSM gsmAccess(true);

For example..on one of the SIM's that worsk this is my output:

Stating DEBUG
AT%13%
0 9>AT%13%%13%%10%OK%13%%10%
AT+CGREG?%13%
9 40>AT+CGREG?%13%%13%%10%+CGREG: 0,1%13%%10%%13%%10%OK%13%%10%
AT+IFC=1,1%13%
40 57>AT+IFC=1,1%13%%13%%10%OK%13%%10%
AT+CMGF=1%13%
57 75>%19%%17%AT+CMGF=1%13%%13%%10%OK%13%%10%
AT+CLIP=1%13%
75 91>AT+CLIP=1%13%%13%%10%OK%13%%10%
ATE0%13%
91 102>ATE0%13%%13%%10%OK%13%%10%
AT+COLP=1%13%
102 108>%13%%10%OK%13%%10%
Config complete DEBUG

but on the SIM Cards that don't work I allways get an output that makes me believe the card isn't registering on the network:

AT%13%
0 9>AT%13%%13%%10%OK%13%%10%
AT+CGREG?%13%
9 40>AT+CGREG?%13%%13%%10%+CGREG: 0,2%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
40 71>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
71 102>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
102 5>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
5 36>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
36 67>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
67 98>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
98 1>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
1 32>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
32 63>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
63 94>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
94 125>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
125 28>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
28 59>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
59 90>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
90 121>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
121 24>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%
24 55>AT+CGREG?%13%%13%%10%+CGREG: 0,3%13%%10%%13%%10%OK%13%%10%
AT+CGREG?%13%

It just goes on and on allways with these messages AT+CREG?%13%

  • I have 7 sim cards;
  • All the sim cards belong to the same network operator;
  • 2 of them work, the other 5 all give the same problem;
  • All of the 7 sim's work on a mobile phone (tested all of them);
  • None of them have PIN number set;
  • I noticed not all the sim cards connectors have the same size (plastic part is allways of the same size), but I believe this is "normal" (they all work on the same mobile phone) and on the group of 5 sims that don't work I have of both larger and smaller types os sim connectors and none works :slight_smile:

Can anyone help please?

Thank you in advance

I've just noticed one pattern on my problem, I continued my tests...and I noticed that all the sim's that work are prepaid, and all that don't work are postpaid.... I wouldn't think that this should be a problem...however tested 15 cards, 5 were prepaid and all worked...the other 10 were postpaid and none worked... too much coincidence? Is there anything that should be done to register a postpaid card???

Just to let everyone know...the problem was that my network operator was blocking GPRS data...even though I only need to send SMS, the GSM shield isn't able (apparently) to register to the network when GPRS is not available...

Problem solved :slight_smile:

I have the same problem. How did u get the gprs unblocked