#include <Arduino.h>

const int buttonPin = 4;  // Reed switch - don't forget the pull down resistor.
const int ledPin =  2;    // Internal LED

void setup() {
  Serial.begin(9600);  
  // initialize the pushbutton pin as an input
  pinMode(buttonPin, INPUT);
  // initialize the LED pin as an output
  pinMode(ledPin, OUTPUT);
}

void loop() {
  int buttonState = digitalRead(buttonPin);
  Serial.println(buttonState);

  if (buttonState == HIGH) {
    digitalWrite(ledPin, HIGH);
  } else {
    digitalWrite(ledPin, LOW);
  }
  delay(500);
}