#include <LiquidCrystal.h>
LiquidCrystal lcd(7,6,5,4,3,2);
int buzzer = 8;

void setup()
{
  lcd.begin(16, 2);
  pinMode (11,OUTPUT);
  pinMode (10,OUTPUT);
  pinMode (9,OUTPUT);
  pinMode (8, OUTPUT);
}

void loop(){
int gas_data;
gas_data = analogRead(A0);
lcd.setCursor(0,0);
lcd.print("Gas :");
lcd.setCursor(0,1);
lcd.print("Status:");
lcd.setCursor(7,0);
lcd.print(gas_data);
if(gas_data > 900) {
  digitalWrite(9,HIGH);
  tone (buzzer, 2000,500);
  delay(100); digitalWrite(9,LOW);
  lcd.setCursor(7,1);
  lcd.print("BAHAYA");
  }
  else if(gas_data > 500)
  {
    digitalWrite(10, HIGH);
    tone(buzzer, 1500, 500);
    delay(100);
    digitalWrite(10, LOW);
    noTone(buzzer);
    lcd.setCursor(7,1);
    lcd.print("HATI-HATI");
    }
    else {
      digitalWrite(11,HIGH);
      delay(100);
      lcd.setCursor(7,1);
      lcd.print("AMAN");
      }
delay(100);
lcd.clear();
}