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Hello all,

Did anyone have this problem:

GSM no response
Registration 0

Is there something else you have to do to get it to work?

Ecave

Yes, I keep getting this problem. Did you ever figure out how to resolve these issues?

If so, can you show me how you fixed it?
« Last Edit: December 06, 2011, 05:55:11 pm by fulvio » Logged

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Havn't fixed it yet. Even by using the usb to serial 232 cable and a MX232N chip and using a voltage divider to decrease the input RX port of the SIM900 module its not responding to any of my AT commands. There's some additional underlying problem than it jsut being brought down to 2.8V. Unless I burnt the module already. But its doing the same thing as it did when I first bought it so its something im not doing right.
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Hi All,

I am working with a iComSat V1.0 Shield with a SIM900 module on it and have a major problem working out how to control it's power and reset from within software.

When the stack is initially powered up the Shield goes into a standby mode and requires you to press the power button on the shield to fully power up.

Secondly, when the Arduino is reset, the Shield is not, again it has its own reset button.

Has anyone found a way to override these buttons in software or, if need be, hardware?
As the Arduino is running at 5V and the SIM900 at 3.3V I am reluctant to try and override the buttons with I/O pins directly.

The application calls for the product to be inside a locked box so having to push buttons renders the shield useless in this application.



I could not get my shield working with the Arduino UNO. Are you able to provide any sample code as I keep getting "no response" and "SMS ERROR" when trying to send an SMS or do practically anything with it.

It powers on, I hold the PWR button so then the STATUS LED displays. NET flashes every now and then but like I said I just keep getting "no response" every single time. I'm running serial and gsm at 9600 baud rate if that helps.
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How do you have the jumpers set? 
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I could not get my shield working with the Arduino UNO. Are you able to provide any sample code as I keep getting "no response" and "SMS ERROR" when trying to send an SMS or do practically anything with it.

It powers on, I hold the PWR button so then the STATUS LED displays. NET flashes every now and then but like I said I just keep getting "no response" every single time. I'm running serial and gsm at 9600 baud rate if that helps.

I'm not sure whether this is relevant to your problem. But, you might want to look at this thread: http://www.seeedstudio.com/forum/viewtopic.php?f=4&t=2203

I know you are using the IteadStudio version, but I think they are pretty similar and had that silly power switch thing (at least the 1st version of Seeedstudio's).
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How do you have the jumpers set?  

The jumpers are correct as per the data sheet so I know that's not the problem.
« Last Edit: December 06, 2011, 05:59:45 pm by fulvio » Logged

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So if I'm using the Debug port I need to use a voltage divider on the RX Port of the gsm module?

I can receive messages in Hyperterminal but I get no response to the commands I send.

The Shield should already step down the voltages right?

Are you able to provide the correct jumper settings for use with Hyperterminal?

I am trying to follow this example:

http://seeedstudio.com/wiki/GPRS_Shield#Support

But I'm not sure what it means when it says to do the following:

4. Make sure the GPRS_TX & GPRS_RX jumpers on the GPRS Shield are mounted in SWSerial position - that is we want GPRS_TX to be connected to D7(RX) and GPRS_RX to D8(TX)

I have uploaded the correct sketch to my Arduino already and am just waiting to setup the above jumper settings in the correct positions in order to allow the sending of AT commands.
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Szeged/HU
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fulvio I resolved the problem! smiley-cool
the modul can communicate! smiley-mr-green
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fulvio I resolved the problem! smiley-cool
the modul can communicate! smiley-mr-green

Oh really!? How'd you get it to work? Can you please explain in detail so I can get it working?
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first off all:
I use arduino mega, and I installed this code:

#include <string.h>

char incoming_char=0;

void setup()
{
  Serial.begin(9600);
  Serial1.begin(9600);
 
  Serial.println("Starting Communication...");
}

void loop() {

  if(Serial1.available() >0)
  {
    incoming_char=Serial1.read();
    Serial.print(incoming_char);
  }
 
  if(Serial.available() >0)
  {
    incoming_char=Serial.read();
    Serial1.print(incoming_char);
  }
}


in the icomsat modul I use external DC in 5V and not the arduino internal DC supply, because arduino can't give much current like 2A
thats good.
and I use the arduino RX1/TX1 pins, for the communication.The newSerial.cpp, newSerial.h
thats all the wiring and coding

important.:
Quote
The DTR signal must be pulled to low level voltage when DTE is sending data to the module.
Otherwise, the CTS signal may always not be asserted by module and the handshaking will not be established

so I use:
I pulled the DTR signal low level voltage a second  ONCE  and no more.
then the comminication is good for the future, and then no more pulled to low this because the handshaking didn't  setted.
it work

if you wanna read more about flow control:

* serial.pdf (283.19 KB - downloaded 31 times.)
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So has anyone actually been able to use the iComSat to send a text message? How about an e-mail containing data? I recently bought one of these shields from http://iteadstudio.com and I keep getting the same error messages as everyone else:


system startup

no response

Received SMS from (sim position: 65534)

 

Command: systeÿ+

Check_Protocol

Send SMS to 5195554444                                        ****(I am actually using my personal cell phone number not ‘5195554444’)

SMS ERROR



You would think that the example included in the library that you can download from http://iteadstudio.com would actaully work.
Also I want to note that I am using  5V 1A to power the GSM board directly. I know that 2A is recommended; however I do not plan on making phone calls, just text and e-mail.
« Last Edit: January 10, 2012, 09:41:15 am by Sparked » Logged

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Quote
I know that 2A is recommended; however I do not plan on making phone calls, just text and e-mail.
It's not just for phone calls, it's for everything.

Are you sure the device is registered to the network?  There is an LED that has a varying blink rate to indicate network registration.  I've seen people get confused by the frequency of the blink rate so the easiest way to tell if the device is registered to the network is to simply call the number from another phone.  Depending on the service provider it should go straight to voice mail if it's not registered.  If it is registered then it should ring continuously. 
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Thanks for the response.
The light is flashing once every 3 seconds as it is supposed to when connected to the network. I was able to call the device and saw the "RING" in my terminal program. I am waiting on a new power supply that will give me 5v 2a, and hopefully this will fix my problem. I will report back once I get the new supply.

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Eagerly awaiting the results from you guys...  smiley
I am sourcing for a reliable GSM/GPRS module to purchase for my project.

I am also waiting for the Arduino GPRS/GSM Shield to complete its incubation phase in the Labs - highly anticipated...
http://labs.arduino.cc/GPRS/Index

Cheers!
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Ok,
So I found a 12V 7Amp power supply that I have plugged into my Arduino Mega. I believe this should work as the iComSat has it's own voltage regulator that gets power from the Vin pin on the Arduino board. Using the code that tbarat posted, and using pins 6,7 as my RX1,TX1, I was able to communicate with the SIM900.  I could send it the AT command with an "OK" response. I checked that the SMS message center number is set correctly, and also checked the band frequency (+CBAND: GSM850_MODE,ALL_BAND). I assume this is correct, doing a bit of research I found that my carrier operates on GSM850/1900. I was able to call my iComSat and saw the "RING" on the terminal display.

Anyways I still have a problem.  When I try to send a text message with the CMGS="+15554445555" it responds with the '>' sign meaning it is ready for me to type text; however when I finish typing and hit enter the terminal program shows another '>' sign....
I wait, and wait but the text message never comes. 

Any ideas of what I might be missing here?
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