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Topic: EFCom GPRS/GSM Shield (Read 2584 times) previous topic - next topic


Hello guys,

I just received my EFCom GPRS/GSM Shield from Singapore today. i set everything up and loaded the example from Arduino IDE, and tried different ones. However; its not working well for some reason. Basically out of like hours and so many tries, i managed to make few calls, but thats about it. i tried to figure the problem out and compare what i've done at the beginning to what i've done when it worked, but i can seem to find anything different. Even when i made the few calls, the call drops after 30-40 seconds. and and i can see the network signal restarting or something along with the SAT light.

Basically i can load the code and run everything, for for example when i load the "Receive Call" example, all i get in the serial monitor is "Receive Voice Call" and it'll stay like this forever. when it worked for me for a few times, i get "Waiting for a call" after a like 20 seconds after the first message. I read on different websites and stuff that it needs a firmware update or something , but that was before i had a several successful attempts. I'm still really new to all this stuff, and can't seem to fully understand some of the stuff i read about AT commands and some other applications. Not even sure if thats related to what i'm doing.

I'd really appreciate it if someone could help me and guide me on what might be the problem.

Tried on different computers (Windows 7, Window8)
Tried different sim cards and tested them.
Power : USB + 9v battery
network coverage is excellent in my area
Shield: EFCom GPRS/GSM Shield  http://www.elecfreaks.com/wiki/index.php?title=EFCom_GPRS/GSM_Shield

can someone also point out what is "buad 9600" ? that might be a really dumb question , but please excuse my lack of knowledge as i'm still fresh.

code :

Code: [Select]
Receive Voice Call

This sketch, for the Arduino GSM shield, receives voice calls,
displays the calling number, waits a few seconds then hangs up.

* GSM shield
* Voice circuit. Refer to to the GSM shield getting started guide
   at http://arduino.cc/en/Guide/ArduinoGSMShield#toc11
* SIM card that can accept voice calls

With no voice circuit the call will connect, but will not send or receive sound
created Mar 2012
by Javier Zorzano

This example is in the public domain.



// Include the GSM library
#include <GSM.h>

// PIN Number
#define PINNUMBER ""

// initialize the library instance
GSM gsmAccess;
GSMVoiceCall vcs;

// Array to hold the number for the incoming call
char numtel[20];           

void setup()
  // initialize serial communications and wait for port to open:
  while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only

  Serial.println("Receive Voice Call");
  // connection state
  boolean notConnected = true;
  // Start GSM shield
  // If your SIM has PIN, pass it as a parameter of begin() in quotes
      notConnected = false;
      Serial.println("Not connected");
  // This makes sure the modem correctly reports incoming events
  Serial.println("Waiting for a call");

void loop()
  // Check the status of the voice call
  switch (vcs.getvoiceCallStatus())
    case IDLE_CALL: // Nothing is happening
    case RECEIVINGCALL: // Yes! Someone is calling us
      Serial.println("RECEIVING CALL");
      // Retrieve the calling number
      vcs.retrieveCallingNumber(numtel, 20);
      // Print the calling number
      // Answer the call, establish the call
    case TALKING:  // In this case the call would be established
      Serial.println("TALKING. Press enter to hang up.");
      Serial.println("Hanging up and waiting for the next call.");     

Thanks in advace


could someone please help me ?

i should mention one thing, we i run the serial monitor for Receive calls, and call the sim card it rings, i even can hear a ring tone when i plug headphones into the headphone jack. but nothing on the serial monitor.

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