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This example is for Wiring version 1.0 build 0100+. If you have a previous version, use the examples included with your software. If you see any errors or have comments, please let us know.

Hall sensor by Juan Guillermo (Coco) Gomez
A hall sensor is a magnetic field sensor, it can detect when a magnet is in the proximity. This example turns on the Wiring board LED when a magnet is near the Hall sensor

    int pinHall = 8;  // Pin for the Hall sensor

    void setup()
    {
      pinMode(WLED, OUTPUT);  // sets the digital pin as output
      pinMode(pinHall, INPUT);  // sets the digital pin as input
    }

    void loop()
    {
      if (digitalRead(pinHall) == HIGH)  // If a magnet is near the Hall sensor
      {
        digitalWrite(WLED, HIGH);  // turns ON the LED
      }
      else
      {
        digitalWrite(WLED, LOW);   // turn OFF the LED
      }
    }