int count = 0;
int buttonState; // \variabel untuk menyimpan
int lastButtonState = 0; //variabel untuk menyimpan keadaan tombol terakhir
long  lastDebounceTime = 0; //variabel untuk waktu debounce
const long PROGMEM debounceDelay = 30; //waktu untuk membaca tombol hingga noise debounce hilang 
//semakin kecil semakin cepat pembacaan tombol

void setup() {
  /*  
  A  => d9
  B  => d8
  C  => d7
  D  => d6
  E  => d5
  F  => d4
  G  => d3
  DP => d2
  */
  DDRD |= B11111100;
  DDRB |= B00000011;
  DDRC &= !B00000001;
  Serial.begin(9600);

}

//fungsi untuk menampilkan angka pada 7-segment display
void display_number(int num){
  switch(num){
    case 0:
      PORTB = B11111100;
      PORTD = B00001111;
      break;
    case 1:
      PORTB = B11111110;
      PORTD = B01111111;
      break;
    case 2: 
      PORTB = B11111100;
      PORTD = B10010100;
      break;
    case 3:
      PORTB = B11111100;
      PORTD = B00110100;
      break;
    case 4:
      PORTB = B11111110;
      PORTD = B01100111;
      break;
    case 5:
      PORTB = B11111101;
      PORTD = B00100111;
      break;
    case 6:
      PORTB = B11111101;
      PORTD = B00000100;
      break;
    case 7:
      PORTB = B11111100;
      PORTD = B01111100;
      break;
    case 8:
      PORTB = B11111100;
      PORTD = B00000100;
      break;
    case 9:
      PORTB = B11111100;
      PORTD = B00100100;
      break;
    case 10:
      PORTB = B11111100;
      PORTD = B01000100;
      break;
    case 11:
      PORTB = B11111111;
      PORTD = B00000100;
      break;
    case 12:
      PORTB = B11111101;
      PORTD = B10001100;
      break;
    case 13:
      PORTB = B11111110;
      PORTD = B00010100;
      break;
    case 14:
      PORTB = B11111101;
      PORTD = B10000100;
      break;
    case 15:
      PORTB = B11111101;
      PORTD = B11000100;
      break;
  }
}

void loop() {
  int reading = (PINC & B00000001);
  // jika keadaan switch berubah, karena noise atau ditekan tahan:
  if (reading != lastButtonState) {
    // reset debouncing timer
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    /* ketika pembacaan (reading) sudah berada pada waktu yang lebih lama
    dari waktu delay untuk menghilangkan debounce, maka nilai 
    buttonState berubah menjadi nilai pembacaan */

    // jika nilai buttonState berubah:
    if (reading != buttonState) {
      buttonState = reading;

      // toggle penambahan counter jika buttonState baru bernilai 1
      if (buttonState == 1) {
        count = count + 1;
      }
    }
  }
  Serial.println(lastButtonState);
  lastButtonState = reading;
  if(count > 15){
    count = 0;
  }

  display_number(count);
}