/*
 LightSwitchPullup2a
 Turn an LED on and off.
 Internal pullup version.
 */

const int pushButtonPin = 2;  // connect the push button to digital pin 2
const int ledPin = 13;        // connect the LED to pin 13
boolean buttonState;          // stores current button state 

void setup() {
  pinMode(pushButtonPin, INPUT);  // make the pushbutton's pin an input
  digitalWrite(pushButtonPin, HIGH);  // turn on internal pullup resistors
  pinMode(ledPin, OUTPUT);        // make LED's pin an output
}

void loop() {
  buttonState = digitalRead(pushButtonPin);  // read the input pin

  // set LED state accordingly
  // note the inverted logic resulting from using pullup resistors.
  digitalWrite(ledPin, !buttonState);        // turn the LED on or off
}