int button = 13; 
int counter = 0; 
int tombol_naik = 0; 
int tombol_akhir = 0; // ketika counter sudah menunjukkan angka 9 
void setup() { 
// put your setup code here, to run once: 
pinMode(button, INPUT); 
Serial.begin(9600); 
} 
void loop() { 
// put your main code here, to run repeatedly: 
  tombol_naik = digitalRead(button); 
  if(tombol_naik != tombol_akhir){ 
    if(tombol_naik == HIGH){ 
      if(counter == 9){ 
        counter = -1; 
      } 
      counter++; 
      Serial.println(counter); 
    } 
  }