hall-effect.ino

int led = 13;//LED pin
int sensor = 10; //sensor pin
int val; //numeric variable

void setup()
{
  pinMode(led, OUTPUT);
  pinMode(sensor, INPUT); //set sensor pin as input
}

void loop()
{
  val = digitalRead(sensor); //Read the sensor
  if(val == HIGH) //when magnetic field is detected, turn led on
  {
    digitalWrite(led, HIGH);
  }
  else
  {
    digitalWrite(led, LOW);
  }
}