Libelium GPRS and Cutecom

So I am working on an undergraduate research project and I have run into a wall that I can't get across. I am working with the libelium GPRS shied and I have Cutecom working. When I try to start it I can only get the reply of \0x00. I type in the command of AT and I sometimes get a reply of 'ok' but then nothing works after that. What am I doing wrong?


Have you added the required cap? Is the SIM-card in the module? Big enough power-supply? Connected the antenna?

On my shield I also soldered the shielding on the module itself to the shield.

I've read that with the old firmware you could experience some problems if the command started with something else than "A".

Sorry I have been occupied with a bunch of projects. But yes the sim card is in the module. I have a 12v 1.5 amp power supply and the antenna is also connected. I can get it to talk through cutecome for about 5 seconds now and then it will disconnect. I can get a "OK" response from the "AT" command then I can't do anything else.

I'm not sure what is meant by the required cap though.

I also think that you need a cap' and what about the power supply it's mentionned that you've to use a 12V 2A.

I bought the same shield :)

Are you having any trouble with yours?

For now, i didn't have the power supply ! So it's not really working ! But i already bought the cap :)

I'm not sure what is meant by the cap. Can you explain? I have the shield, the sim card and of course the GPRS itself, but I don't know what the cap is.

It's a capacitor ;)

Sorry I figured it out. I feel like a moron. I actually got it to stay connected in the terminal, but when I send a text, nothing come through. But hey I'm getting closer...

Take off the ATMEGA chip from the Arduino, then connect the board (with the module of course), and you'll be able to use a Serial Terminal to send some AT Commands, but without a power supply (like me), the module turns off automatically after 10 sec.

PS : Be careful when you remove the atmega chip, i broke a pin this morning : :'(

I did that and I got it to work in Cutecom. I sent a text following the tut from their website, but my phone never got the message.

\0x00 (hex), means that the module is off. I got the same issue as you. I bought an antenna, and when I back to school I'll have a power supply, it should be working :)

Did u solve it yet? It sounds like your board is either losing power or you need to upload new firmware.

Check the following:
-ATMEGA processor removed (for serial terminal use)
-capacitor (about 220 uF) soldered on as in the tutorial.
-If you want to use a serial terminal, set both your serial com jumpers (next to the capacitor above) to USB. Otherwise set them to ARD.
-If you’re powering your board through the arduino, set the power jumpers on the shield to 5V. You probably need to plug an adaptor into your arduino as well. In the tutorial they suggest 12V which is a bit overkill - I’d use something smaller.

If it’s still not working, you might want to try uploading new firmware. It’s quite simple and well described in the tutorial.

I can send SMS now :) !

Add a 220uF Capacitor Use pwer supply ;)

it works pretty good :)

Just received the GPRS shield today. With all connected I only receive echo from my commands and sometimes the \0x00. I'm using external power supply (2A) and a small antenna. Tomorrow I'll go to buy some the 220uf cap to try it.

PS: I thinked that they tested all the shields before sending... now I'm not so sure about that :P

Could be a software problem, too. Might want to post your code.

I am not yet in the code phase. What I'm doing is testing the Hilo module before going into programming:

Just soldered the 220uf and connected to a 12v 2A power supply. Result is as before, no reply from gprs module. I’m going to contact libelium for more support.

At the end all I needed to change was to send a LF after the CR commands :P

Great support received from libelium!