// found here: https://arduino.stackexchange.com/questions/3479/how-to-toggle-led-on-button-press

int ledPin = 7;
int buttonPin = 3;
int lastButtonState = HIGH;


void setup() {

pinMode(ledPin, OUTPUT);
pinMode(buttonPin, INPUT_PULLUP);
}

void loop()
{
  // Get the current state of the button
  int currentButtonState = digitalRead(buttonPin);

  // Has the button gone high since we last read it?
 if (currentButtonState == HIGH && lastButtonState == LOW) {
     // Switch the state of the output
     //digitalWrite(ledPin, !digitalRead(ledPin));

    if(digitalRead(ledPin))
       digitalWrite(ledPin, 0);
    else
       digitalWrite(ledPin, 1);
      
  }

  // Store the button's state so we can tell if it's changed next time round
  lastButtonState = currentButtonState;
}