// this constant won't change:
const int BUTTON_PIN = 8;    // the pin that the pushbutton is attached to
const int RELAY_PIN = 7;
const int LED_PIN = 13;       // the pin that the LED is attached to

// Variables will change:
int buttonPushCounter = 0;   // counter for the number of button presses
int buttonState = 0;         // current state of the button
int lastButtonState = 0;     // previous state of the button

void setup() {
  // initialize the button pin as a input:
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  // initialize the LED as an output:
  pinMode(LED_PIN, OUTPUT);
  pinMode(RELAY_PIN, OUTPUT);
  // initialize serial communication:
  Serial.begin(9600);
}

void loop() {
  // read the pushbutton input pin:
  buttonState = digitalRead(BUTTON_PIN);

  // compare the buttonState to its previous state
  if (buttonState != lastButtonState) {
    // if the state has changed, increment the counter
    if (buttonState == LOW) {
      // if the current state is HIGH then the button went from off to on:
      buttonPushCounter++;
      Serial.println("on");
      Serial.print("number of button pushes: ");
      Serial.println(buttonPushCounter);
    } else {
      // if the current state is LOW then the button went from on to off:
      Serial.println("off");
    }
    // Delay a little bit to avoid bouncing
    delay(50);
  }
  // save the current state as the last state, for next time through the loop
  lastButtonState = buttonState;

  // turns on the LED every four button pushes by checking the modulo of the
  // button push counter. the modulo function gives you the remainder of the
  // division of two numbers:
  if (buttonPushCounter % 4 == 0) {
    digitalWrite(LED_PIN, LOW);
    digitalWrite(RELAY_PIN, LOW);
  } else {
    digitalWrite(LED_PIN, HIGH);
    digitalWrite(RELAY_PIN, HIGH);
  }

}