Hall_sensor.ino

const int ledPin = 13;// the led attach to pin13
int digitalPin = 2; // attach to pin 2
boolean digitalValue=0;// variable to store the value coming from pin2
void setup() 
{
  pinMode(digitalPin,INPUT);//set the state of pin2 as INPUT
  pinMode(ledPin,OUTPUT);//set the state of pin13 as OUTPUT
  Serial.begin(9600); // initialize serial communications at 9600 bps
}
void loop() 
{ 
  digitalValue=digitalRead(digitalPin); //read the value of pin2
  Serial.print("Digital Value "); // print label to serial monitor 
  Serial.println(digitalValue); 
  if( digitalValue==HIGH )
  {
    digitalWrite(ledPin,LOW);//turn off the led
  }
  else
  {
    digitalWrite(ledPin,HIGH);//turn on the led
  }
  delay(1000);
}