Send & receive data using Libelium GPRS Shield?

Forum 2005-2010 (read only) Hardware Interfacing
1

I've started this new thread as I've had some success with Libelium's GPRS shield, but am very stuck with data operations over GPRS.

Here is Libelium's general introduction which is a good start:

http://www.libelium.com/squidbee/index.php?title=New_GPRS_module_for_Arduino_(Hilo_-_Sagem)

I've managed to send and receive SMS, monitor and make calls, but the shield appears to die when I send data following the KTCPSND command.

Looking at page 17 of the Sagem module datasheet it looks like nearly 2 amps are drawn in a GPRS transmission burst:

http://www.alphamicro.net/resources/Sagem/HiLo/URD1-5635.1-005-70086-ed-05-HiLo-technical-specification.pdf

Libelium's introduction recommends a 220uf capacitor on their shield to mitigate this current spike, I have one in place. In my experience, without the capacitor, the shield would become uncommunicative after about 10 seconds with no AT commands being sent.

Here are the AT commands I'm using, this is testing sending and receiving data using the mail server of the company providing support for the Sagem module in the UK. I should see the sent string echoed back to the receive buffer, as I do during a telnet session:

AT+KCNXCFG=1,"GPRS","payg.talkmobile.co.uk"
AT+KCNXTIMER=1,60,2,70
AT+CGATT=1
AT+KTCPCFG=1,0,"mail.alphamicro.net",10003
AT+KPATTERN="--END--"
AT+KTCPCNX=1
AT+KTCPSND=1,24
HELLO WORLD 1234 --END--
AT+KTCPRCV=1,1000
AT+KTCPCLOSE=1,1

The stall/crash occurs when I send the data "HELLO WORLD 1234 --END--" after seeing the "CONNECT" prompt.

Can anyone confirm they have HTTP data receive working, or have any other suggestions?

2

I will try to help you when I get my module working...

I think my problem its because I dont have an antenna connected to it...

3

Yes you need an antenna to connect to the network that the SIM is registered with, the shield is pretty useless without that unless you want to just manage the data on the SIM card.

4

I trying to connect the Libelium GSM Module with an Arduino Mega, Im not sure if the arduino is giving the module enough juice. I dont get any responce from the module. Any suggestions would be appreciated.

5

Well i think that's not your problem since i'm able to send sms but don't see any responces neither.

6

I finally got everything to work. First you must upgrade the Libelium module with the lastest firmware. after that, use a 12V-2A power supply but you still need a 220uF capacitor (Note that in the tutorial they mention that you can use one or the other)this is not completely correct, you need both of them.

7

hi julio123,

thanks for posting your good news, this has inspired me to return my attention to the module.

Here's the guide for uploading the latest firmware:
http://www.libelium.com/squidbee/index.php?title=Uploading_the_firmware

I'll post an update here shortly, hopefully I'll also get a nice result.

bests,
Tobie

8

Thanks Tobie

the tutorial to upgrade the module worked fine, i was able to perform the upgrade without having to solder the wire they mentioned, i carefully placed the wire ina way that got kind of stuck in there and made enough contact to perform the upgrade. I didnt want to solder in such a small and risky part of the board.

Now Im trying to make a remote activation system, mainly i want to activate the device by making a call to it. This is going to allow the device send txt msg every couple of min which is the purpose of my project. I have been looking at the documentation of the module, but i have not idea how im going to do this

Good luck with your project

9

so, I've done a butt ton of research on this, and this thread proved to be the most helpful and informative.

I upgraded the firmware on my libelium GPRS using a duemil gateway (chip removed, obviously)

I now have it connected to my ATMEGA1280, external power (12V SLA battery) with a 220uF cap installed for the spikes.

On the jumpers I have the one next to the cap completely removed and the other one (closer to the edge of the board) on the arduino side.

I have some headers in between but it's basically just slapped onto my mega

I've managed to send a text message through the libelium and it's received on the other devices (i.e. my cell phone)

I can't get an echo when it's in the arduino, when I have it on the duemil gateway using BR@Y I get an echo, it essentially works perfectly. I need full duplex communication for my school project and I can't seem to do it.

Any advice or help? I'm using the arduino 0021 btw, and it is working (for the most part)

I tried using the gateway separately and running wires from the RX and TX ports to the TX & RX ports on my mega and trying to get a response. I could get an echo but it was just a total botch because I couldn't send commands, and that was in USB mode. when I do it in arduino mode I can only send commands....

this stinks. I need help :frowning:

10

nobody knows anything about the libelium shield?

11

Hi,
I have a Sagem Hilo (libelium board) on an arduino One powered by a 12v dc 2A without the additional capacitor installed.
In gateway mode I have non problem to originate http requests (commands are manually issued). If I try to program the arduino to perform the same operations previously issued by hand ... nothing seems to happen. Any suggestion?

Thank you