#include <Servo.h>

// game vars
#define PLAY true
#define STOP false;
bool gameState = STOP;

// button vars
const int buttonPin = 2;
bool buttonState = false;

// sensor vars
const int refSensorPin = A0;
int refSensorValue = 0;
const int sensorPin = A1;
int sensorValue = 0;
int baseValue = 0;

// servo vars
int servoPin = 5;
Servo servo;

void setup() {
  Serial.begin(9600);
  pinMode(buttonPin, INPUT_PULLUP);
  pinMode(LED_BUILTIN, OUTPUT);
  
  servo.attach(servoPin);
  servo.write(0);
  // button interrupt
  EICRA = 0;
  EIMSK = 0;
  // set event on falling edge
  EICRA |= (1 << ISC01);
  // enable INT0
  EIMSK |= (1 << INT0);
  sei();
}

ISR(INT0_vect)
{
  // cod întrerupere externă PD2 /INT0
  gameState = !gameState;
  digitalWrite(LED_BUILTIN, gameState);
}

void loop() {
  if (gameState == false) {
    // calibrate
    sensorValue = analogRead(sensorPin);
    baseValue = sensorValue;
  } else {
    // play
    sensorValue = analogRead(sensorPin);
    if (abs(sensorValue - baseValue) > 5) {
      servo.write(110);
      delay(300);
      servo.write(0); 
      delay(400);
    }
  }
  
}