Is the Gsmshield the right tool to send sms ?


I would like to send sms when the status of a switch is changed. I have choosed to use an Arduino Ethernet and Gsm Shield 2 but I can not get this work properly :

Sometimes the Gsm shields connects properly but most of the time it is not connected. I have seen on the forum that a lot of persons have this problem but I don't find any concrete solution ...

I run the SMS Messages Sender and get the message : AT%13% 0 6>%13%%10%OK%13%%10% AT+CPIN=2925%13% 6 23>%13%%10%+CME ERROR: 3%13%%10% Not connected

The gsm shield is powered with a 1000mA power supply The SIM is placed on the board and the PIN is introduced into the code. The status light is ON and the NET light is blinking. It's an Arduino Gsm Shield 2 : so it has an integrated antenna. I have tested with a new second Arduino and same problem.

Do you have an idea of what I can do to make it work ? Is this Gsmshield the right tool ? Is there another solution more reliable ?

Thanks for your help Mario

The GSM shield can send SMS. I have done it with the same type (Quectel M10 with integrated antenna) on an Arduino Uno and Mega. But I have a SIM card without PIN. In this forum you can read many postings which recommend to remove the PIN. The PIN can be removed when you plug it into a mobile and use configuration functions - I never did it.

Generally using the SIM card of the GSM shield within a mobile shows you if the SIM card is ok and not locked (e.g. after 3 times wrong PIN).

If removing the PIN does not solve your problem check the response of M10 to the command AT, see the second line of your messages list. Hopefully the type of response gives you a hint where to check further. The Quectel M10 handbook should help to interpret the response.

Do you have an Arduino Uno for a test? If the GSM shield and your test software is not working with the Uno then either the shield is defect or your software is not ok. Test it with the GSM examples.

If you are using the Mac version of GSM library then see

I had problems with the autobaud function of M10, see


Hello SupArdu,

Thanks a lot for your reply. I have tested with a second Arduino Uno with the Gsm samples and same results. I'm waiting for a new Gsm shield, hoping that this will solve the problem.

Again thank you for your time.