#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,20,4);
String input;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  for (int i=2;i<=7;i++) {
    pinMode(i, OUTPUT);
  }  
}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.println("Select lamp: 1-6;  9: ALL ON; 0: ALL OFF");
  while (!Serial.available()){}
  input = Serial.readString();
  int nomor = input.toInt();

  if (nomor==0) {
    for (int i = 2; i<=7;i++){
      digitalWrite(i, LOW);
    }
    lcd.setCursor(0,0);
    lcd.print("SEMUA LAMPU MATI..");
  }
  else if (nomor==9){
    for (int i = 2; i<=7;i++){
      digitalWrite(i,HIGH);
    }
    lcd.setCursor(0,0);
    lcd.print("SEMUA LAMPU HIDUP.");
  }
  else {
    for (int i = 2; i<=7;i++){
      digitalWrite(i, i==(nomor+1)?HIGH:LOW);
    }
    lcd.setCursor(0,0);
    if (nomor <=6) {
        lcd.print("Lampu " + String(nomor) + " hidup....");
    }
    else {          
        lcd.print("TAK ADA NOMOR ITU!");
    }
  }
  delay(1000);    
}