/*
 LightToggleLogic
 Toggle an LED on and off.
 */

const int pushButtonPin = 2;    // connect the push button to digital pin 2
const int ledPin = 13;          // connect the LED to pin 13
boolean ledState = LOW;         // used to set LED
boolean lastButtonState = LOW;  // value of buttonState from previous loop iteration

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

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

  // if button goes down and previously it was high...
  if (buttonState == LOW && lastButtonState == HIGH) {
    if (ledState == HIGH)            // toggle LED
      ledState = LOW;
    else
      ledState = HIGH;

    digitalWrite(ledPin, ledState);  // turn the LED on or off
  }

  lastButtonState = buttonState;
}