Go Down

Topic: Arduino GSM Module from ITead Studio (Read 24455 times) previous topic - next topic


Hi all,
problem module On per software


//#define GSM_ON              8 // connect GSM Module turn ON to pin 77    original
#define GSM_ON              9 // connect GSM Module turn ON to pin 77        my changes  (from net !!!)
//#define GSM_RESET           9 // connect GSM Module RESET to pin 35    original
#define GSM_RESET           8 // connect GSM Module RESET to pin 35        my changes but I'm not shure for pin  to RESET

pinMode(9, OUTPUT);

thet's all, power now On at start the test program

testet with icomsat 1.1 and used SoftwareSerial (latest version) instead NewSoftSerial (changes in GSM_Shield.h and ---.cpp)



The library http://code.google.com/p/gsm-shield-arduino/ can control the SIM900 and is shield http://www.open-electronics.org/arduino-gsm-shield/
The library control SMS, CALL and also the GPRS function.
I think that is compatible with ITead Studio (that is a clone) but pay attention because the library that they suggest is our old version.

Now we are developing a new shield for also the the SIM908 module.

The main problem with the SIM900 is the power supply.
The module doesn't drink a lot of current, but the are some spikes when it does some operation. So the power supply must be 12V 1A (more important is the current)



I know this is an old thread but I had just come across it troubleshooting this same shield, and I discovered on page 7 of their published datasheet that the Reset pin is connected to Pin 10.

So the line waldschrat was unsure about should be:

#define GSM_RESET           10 // connect GSM Module RESET

Just figured I should mention.



Apr 17, 2012, 08:30 pm Last Edit: Apr 20, 2012, 01:57 am by utsavdrolia Reason: 1
I am starting my first GSM/GPRS project and about to buy this board. Hence just wanted to confirm that the library from openelectronics (http://code.google.com/p/gsm-shield-arduino/) does work with it, right? And that over all the board is good to use? Apart from the changes mentioned in the past posts, rest is good to go?
My project will be majorly using GPRS to post sensor data online.



It took me a good few hours of tinkering to get the jumpers right, and it meant having to change the pins in the library a number of times until I got it right, but yes it does work with that library and the ITead Studio board. I used "GSM Shield GPRS Library V3.08 (IDE 1.0) beta" and an Arduino Uno R3.

On the board I am using RXD as pin 4, and TXD as pin 5, and then in GSM.cpp I am using:

#define _GSM_TXPIN_ 5
#define _GSM_RXPIN_ 4

One further thing I had to do to get it to work, also in GSM.cpp, is on line 41 I added:

pinMode(GSM_ON, OUTPUT);

because a few lines further down they were pulsing the pins to get the modem to power on except the pin was never set as output. Mixing that in with figuring out what every jumper should be set to led to a frustrating evening. Hope I can save you some headache.

-David Beauchamp


Hi there
I realise this is an old topic but maybe someone will be watching it.
I have just been trying to communicate with the IteadStudio GPRS shield using the softwareSerial library and writing to pins 4 & 5 which is what i have set the shield to.
My issue is i am getting total garbage coming back.
Very few of the characters are in the alphanumeric range, many are over 0x80.

eg if i send AT i get 0x78 0x9F 0x80 0xFE
and if i send ATI i get 0x78 0x9F 0x18 0x66 0x80 0x0

is this in a language OTHER than english or is it returning unicode??



My issue is i am getting total garbage coming back.

Could be a baud rate issue - what are you using?


i also went down to 2400 with similar results


i used the first sketch from http://www.geeetech.com/wiki/index.php/Arduino_GPRS_Shield...a very simple pass thru sketch.


Hard to tell from the on-line docs, but it did mention 115200 in the command reference - worth a try?


Apr 16, 2013, 09:47 pm Last Edit: Apr 16, 2013, 10:57 pm by moshejay Reason: 1
worth a shot but no, that didn't help either.

on a completely different note, i believe the GPRS library offers a TCPIP stack which puzzles me as the SIM900 has a built in TCP stack.
Do you have any thoughts on this or am i mistaken in what i believe?

[EDIT] i have just tried 9600...THAT worked...problem gone away!


I know its an old post, but it may help anyone looking for an answer to this problem:

If your SIM900 GSM module dies when you attempt to connect...

This chip is hungry for power and when you go 'on-line' to make a call or send an SMS etc, it fires up the RF transmitter and it will die if your power supply does not have enough grunt!  It cannot run when powered via the USB cable.

This is no necessarily a problem with the chip/module, it just needs a good stable power source. I use a 2 amp 5v wall wart on any project with these modules and they work great!




Hello you all!
I have a really stupid question for you, I'm as well using GSM Module from Itead studio (http://imall.iteadstudio.com/im120417009.html). It was working fine, but now the Net and the Status LED won't blink at all!.
To power it up I'm using a 9V 1.5A charger as well as the USB port from my computer.


hi there...all i can suggest;
i presume you have checked your power supply adapter (although the USB would be enough to get the LEDs running).
And i presume you have tried pressing the SIM power button for 1/2 sec?
Incidentally, SIMcom recommend a power supply of 2A.



Has someone success switching the SIM900 module on the GBoard (also made by iTead) on/off by software and if so what pin / pulse length did you use? Any suggestion how to debug are also welcome. See also this post http://forum.arduino.cc/index.php?topic=217384.0 for details.

Go Up