#define btn1 4       //Button 1 pada pin D2
#define btn2 5
#define btn3 6
#define LED1 1      //LED1 pada pin D5
#define LED2 2
#define LED3 3
#define restart 7     //Button reset pada pin D8

bool lock = false;

void setup() {
  pinMode(btn1, INPUT);   //Setting I/O
  pinMode(btn2, INPUT);
  pinMode(btn3, INPUT);
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(restart, INPUT);
}

void loop() {
  if(lock == false){               //Jika kunci terbuka, maka
    if(digitalRead (btn1) ==HIGH){       //Jika button 1 ditekan, maka
      digitalWrite(LED1, HIGH);         //LED 1 akan menyala
      lock = true;                     //Mengunci
    }
    else if(digitalRead (btn2) == HIGH){
      digitalWrite(LED2, HIGH);
      lock = true;
    }
    else if(digitalRead (btn3) == HIGH){
      digitalWrite(LED3, HIGH);
      lock = true;
    }
  }
  else{                             //Jika terkunci, maka
    if(digitalRead (restart) == HIGH){ 
      lock = false;                //Terbuka kalau tombol reset ditekan
      digitalWrite(LED1, LOW);
      digitalWrite(LED2, LOW);
      digitalWrite(LED3, LOW);
      delay(200);
    }
  }
}