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Topic: New GPRS module for Arduino (Read 9580 times) previous topic - next topic



When you send the command AT+KTCPSND=1,14, be sure that your that your module is upgraded because it's not, you must to start your message for 'A' character. Anyway, if you are using hiperterminal or similar, you can't see what are you sending, but this doesn't mean that you are sending nothing. The only way to check that the info is sending correctly, is having access to the server and listen in the socket.

Another recomendation: If you want to avoid problems with the EOF pattern, is recommended to change it to a only one character, for example with: AT+KPATTERN="#".

And now, my question: Anyone knows where I can find the famous firmware 5.05 for the module?? The links in this forum are broken. I need to make a TCP connection whitout sending the 'A' character in the first place... help please!

thank you!!


thanks for your answer. I have the new firmware in the module. I found it googling. I have it at home, I will send you it on friday if you want. I only need your email so get it to me by pm.



Sorry that the links to the software is broken.
I can see that the links is not valid anymore, but I can't remember deleting the files at the server so dunno why :(

I will try fix this later.


hi everyone!

I have another question for you. I'm having many problems with the power supply. It's posible to use a external 9 V power supply to powering Arduino, GPRS and GPS module?? how I must connec it?

In this moment, I only can make it works with 12 V. And this voltage is excessive for a wireless device. what can I do? Thanks


hello, i only used the GPRS, if you look the schematics and the datasheet of the regulator, you can see that the maximun tension is 30 (i think, i dont remember exactly), so you can put 12, but the circuit will continue on 3.3.

As i told you, i dont know about the gps or the arduino, but, in gprs, you can power it changing the jumper, or directly in the same pins.

I hope it will helps you.



Thanks, but I believe that this information isn't helpful for me. Sorry.

My shield must to be powered by arduino, because I need that ATMega manage the GPS and GPRS modules. So I have to let the shield jumpers in "Arduino" and "5 V" position.

I think that the current is the problem. I have been measuring all the voltages in the shield and everything is OK. 3,3 in the HiLo and 5 V in the GPS. I soldered a 220uF capacitor between 5V and GND, but seems that isn't enough. Should I use larger capacitors? I need al least 2A  to transmit data.


The links at page 2 is now working again


OK, that's great, thanks Sonped.

I just solve the problem with the power supply. I had to solder a capacitor between 5 V and GND bigger enough to generate 2 A for the transmision peak.

In my case, I'm using a 470uF capacitor and the voltage must to be al least 8 or 9 V.

If you are using less voltage, the capacitor must to be bigger and vice versa.

See you!!


Did some of you know of a GPRS module which use something else than AT-commands, maybe a PPP interface or similar ?


Hi, I'm trying to develop a system with GPRS-hilo, and I'm not able to initialize the modem. I try to follow the instructions about the POK_IN pulse, and the modem does nothing, CTS is always '0'. In addition, VGPIO is always at 2.8V, although POK_IN low-pulse is not given.

Someone can help me?




Does anyone know if the Libelium GPRS shield ships with any given frequency band set by default? I am in the US, I may need to change the band (to 850/1900 MHz) if the module is preconfigured with 900/1800MHz.

If a change is necessary, how do I make set the band?



I would be grateful if someone could help me, I'm having some troubles using the Hilo sagem module to send messages thro gprs, I'm using this commands:


Now nothing is happening, jus a no carrier response, but last week I had a connected response but then de module freezes, I'm kind a newbie in that stuff, if anyone could help I ll be grateful.


Do you have a 5V 2A power supply direct to the shield? It´s very important to maintain the connection stable.


now im pluging arduino directly by electricity and im using a capacitor to maintain the power supply, i get the connect part but i can´t send anything


Aug 28, 2009, 04:17 am Last Edit: Aug 28, 2009, 02:11 pm by Manoel Reason: 1
I solve the problem and Arduino it's working both in stand-alone mode and as USB gateway modem.

The antenna is essential; without the antenna  a NO CARRIER message appears.

I use a power supply (ps) of 9V 3A first, feeding Arduino board using 2.1mm center-positive plug into the board's power jack.

To the following please consider the figure
Description of the components in the Libelium tutorial


If you consider the Arduino board oriented so the power jack is at 9h (your left) the shield jumpers are:

voltage jumpers right position - Arduino 5v

******************stand alone mode ***************

1) upload the program, for example lost call (Libelium tutorial)

2) serial com jumpers: left position (Arduino).

Now the sketch lost call may be executed for example, disconnecting the USB cable from computer, disconnect and connect the power jack.

******************USB gateway mode ***************

The only way I was succeed until now to use the GPRS shield  as an USB gateway is using an Arduino board without the ATMEGA microcontroler; to work as a gateway, again with the 9v external supply:
voltage jumpers right position - Arduino 5v
serial com jumpers: right position - USB gateway

I use the hyperterminal program with the sets  referred  in  Libelium tutorial.
To begin the comunication   press about 2 s the shield on/off button; it appears a PSST message indicating that  SAGEM module is ready to listen and execute the AT commands.


Now  I 'm using a AC-DC ps with 9V 1000mA with the 220microFarads capacitor recommended in Libelium tutorial; the Windows hyperterminal connection remains stable after several  hours.

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