Adrino: Photoresistor

// 4 pins of the stepper motor board
#define _PIN1 8
#define _PIN2 9
#define _PIN3 10
#define _PIN4 11

// Interruption on PIN2
#define ITR_PIN 2


volatile int count = 0;
volatile int triggers = 0;
volatile int lastTrigger = 0;

const unsigned int BAUD_RATE = 9600;

void Trigger()
{
  triggers++;
}


void setup()
{
  cli();
  pinMode(ITR_PIN, INPUT_PULLUP);
  attachInterrupt(0, Trigger, FALLING);
  sei();

  Serial.begin(BAUD_RATE);
  Serial.println("Go");
  Serial.flush();
}


void loop()
{
  if (triggers != lastTrigger)
  {
    // Debounce count
    lastTrigger = triggers;
    count++;

    // Output count
    Serial.println(count);
    Serial.flush();
  }
  delay(200);
}