GSM shield unstable....

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1

Does anyone know why my gsm shield is so unstable? It works fine sometimes, and suddenly it stopp working. I use the gsm sketch for send sms...

2

A bit more information might be helpful.

What shield is it ?

What does it stop doing ?

Where is the code for a review ?

Cheers Pete.

3

The shield is a SIM900 gsm/gprs shield. The code is the example sketch for sendsms under GSM in Arduino.
It hangs when I open the serial monitor. It just says "SMS Messages Sender"

/*
 SMS sender

 This sketch, for the Arduino GSM shield,sends an SMS message
 you enter in the serial monitor. Connect your Arduino with the
 GSM shield and SIM card, open the serial monitor, and wait for
 the "READY" message to appear in the monitor. Next, type a
 message to send and press "return". Make sure the serial
 monitor is set to send a newline when you press return.

 Circuit:
 * GSM shield
 * SIM card that can send SMS

 created 25 Feb 2012
 by Tom Igoe

 This example is in the public domain.

 http://arduino.cc/en/Tutorial/GSMExamplesSendSMS

 */

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

#define PINNUMBER ""

// initialize the library instance
GSM gsmAccess;
GSM_SMS sms;

void setup()
{
  // initialize serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }

  Serial.println("SMS Messages Sender");

  // connection state
  boolean notConnected = true;

  // Start GSM shield
  // If your SIM has PIN, pass it as a parameter of begin() in quotes
  while (notConnected)
  {
    if (gsmAccess.begin(PINNUMBER) == GSM_READY)
      notConnected = false;
    else
    {
      Serial.println("Not connected");
      delay(1000);
    }
  }

  Serial.println("GSM initialized");
}

void loop()
{

  Serial.print("Enter a mobile number: ");
  char remoteNum[20];  // telephone number to send sms
  readSerial(remoteNum);
  Serial.println(remoteNum);

  // sms text
  Serial.print("Now, enter SMS content: ");
  char txtMsg[200];
  readSerial(txtMsg);
  Serial.println("SENDING");
  Serial.println();
  Serial.println("Message:");
  Serial.println(txtMsg);

  // send the message
  sms.beginSMS(remoteNum);
  sms.print(txtMsg);
  sms.endSMS();
  Serial.println("\nCOMPLETE!\n");
}

/*
  Read input serial
 */
int readSerial(char result[])
{
  int i = 0;
  while (1)
  {
    while (Serial.available() > 0)
    {
      char inChar = Serial.read();
      if (inChar == '\n')
      {
        result[i] = '\0';
        Serial.flush();
        return 0;
      }
      if (inChar != '\r')
      {
        result[i] = inChar;
        i++;
      }
    }
  }
}
4

What arduino do you have it connected to

if it is NOT an UNO then you need to read this

5

It is an UNO, I've also tried it on a NANO. Same result...

6

so do you get the "Not connected" message at all or does it just hang after "SMS Messages Sender" ?

7

It just hangs after the "SMS Messages Sender"...