int inputSwitchPin = 2;
int lastState = HIGH;

void setup() {
  Serial.begin(9600);
  pinMode(inputSwitchPin, INPUT);
}

void loop() { 
  int pinState = digitalRead(inputSwitchPin);

  if (pinState != lastState) {
    Serial.println(pinState?"released":"pressed");
    lastState = pinState;
  }
}

