Detection of DS18B20, arduino Mega I just bought a DS18B20 temperature sensor. I can't detect the device when i run this code :

#include &lt;OneWire.h&gt;
#include &lt;DallasTemperature.h&gt;

// Data wire is plugged into pin 10 on the Arduino
#define ONE_WIRE_BUS 10

// Setup a oneWire instance to communicate with any OneWire devices 
// (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);

// Pass our oneWire reference to Dallas Temperature.
DallasTemperature sensors(&amp;oneWire);

void setup(void)
{
  // start serial port
  Serial.begin(9600);
  Serial.println("Dallas Temperature IC Control Library Demo");

  // Start up the library
  sensors.begin();
 }


 void loop(void)
{
  // call sensors.requestTemperatures() to issue a global temperature
 // request to all devices on the bus
  Serial.print(" Requesting temperatures...");
  sensors.requestTemperatures(); // Send the command to get temperatures
  Serial.println("DONE");

  Serial.print("Temperature for Device 1 is: ");
  Serial.print(sensors.getTempCByIndex(0)); // Why "byIndex"? 
    // You can have more than one IC on the same bus. 
    // 0 refers to the first IC on the wire

}




Here are my connections:

and output on Serial Terminal is: 

      "Temperature for Device 1 is: -127.00 Requesting temperatures...DONE"

I also tried to detect the address of my device but with no success.
I am using an arduino Mega 2560, i have read in some forms that maybe it has something to do with Clock speed or something like that.

I appreciate your help.

I mainly followed this tutorial : http://www.hobbytronics.co.uk/ds18b20-arduino
In the Tutorial, which you are following, it says,


  So we will use the 2 wire method. Simply connect both the GND and VDD
  pins to 0V (yes both)


and it shows:



but I think you are missing this step, because i can't see any connection like that here: