const int  buttonPin = 2;
const int ledPin = LED_BUILTIN;
//counter for the number of button presses
int buttonPushCounter = 0;
//current state of the button
int buttonState = 0;
//previous state of the button
int lastButtonState = 0;

void setup() {
  pinMode(buttonPin, INPUT);
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);
}

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

  // compare the buttonState to its previous state
  if (buttonState != lastButtonState) {
    // if the state has changed, increment the counter
    if (buttonState == HIGH) {
      buttonPushCounter++;
      Serial.println("on");
      Serial.println("number of button pushes: ");
      Serial.println(buttonPushCounter);
    } else {
      Serial.println("off");
    }
    delay(50);
  }

  // save state
  lastButtonState = buttonState;
}