Arduino GSM shield GSM_READY not ready ever I am using an Arduino Mega and an Arduino GSM shield. I am using the receive SMS example under GSM in the Arduino IDE. My GSM shield's hardware IP is set correctly.

Here is the sketch:


/*
 SMS receiver

 This sketch, for the Arduino GSM shield, waits for a SMS message
 and displays it through the Serial port.

 Circuit:
 * GSM shield attached to and Arduino
 * SIM card that can receive SMS messages

 created 25 Feb 2012
 by Javier Zorzano / TD

 This example is in the public domain.

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

*/

// include the GSM library
#include &lt;GSM.h&gt;

// PIN Number for the SIM
#define PINNUMBER ""

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

// Array to hold the number a SMS is retreived from
char senderNumber[20];

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 Receiver");

  // connection state
  boolean notConnected = true;

  // Start GSM connection
  while (notConnected) {
    if (gsmAccess.begin(PINNUMBER) == GSM_READY)
      notConnected = false;
    else {
      Serial.println("Not connected");
      delay(1000);
    }
  }

  Serial.println("GSM initialized");
  Serial.println("Waiting for messages");
}

void loop() {
  char c;

  // If there are any SMSs available()
  if (sms.available()) {
    Serial.println("Message received from:");
    // Get remote number
    sms.remoteNumber(senderNumber, 20);
    Serial.println(senderNumber);
    // An example of message disposal
    // Any messages starting with # should be discarded
    if (sms.peek() == '#') {
      Serial.println("Discarded SMS");
      sms.flush();
    }

    // Read message bytes and print them
    while (c = sms.read())
      Serial.print(c);
    Serial.println("\nEND OF MESSAGE");

    // Delete message from modem memory
    sms.flush();
    Serial.println("MESSAGE DELETED");
  }
  delay(1000);
}


The issue is this line:

if (gsmAccess.begin(PINNUMBER) == GSM_READY)


The serial monitor outputs everything until that line.

It just never gets past it, so I assume it cannot connect? The SIM has no pin code: I have tried it with my phone. The SIM has full signal strength when in my phone. I have tried my other SIM card also but the same thing happens.

This seem to be the same question, yet no answer:
http://forum.arduino.cc/index.php?topic=270551.0
You could always try setting a pin code and then retry
http://arduino.cc/en/Tutorial/GSMToolsPinManagement

What version of the Arduino IDE are you using ? Also, are you sure you are suppying the board correctly ? "It is recommended that the board be powered with an external power supply that can provide between 700mA and 1000mA. Powering an Arduino and the GSM shield from a USB connection is not recommended, as USB cannot provide the required current for when the modem is in heavy use."