#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);
 const int buttonPin =2;
 const int potPin = A0;
 int gasValue =0;
 int buttonState =0;
 int lastButtonState =0;

 void setup(){
  lcd.begin(16, 2);
   pinMode (buttonPin, INPUT);
  lcd.setCursor(5,0);
  lcd.print("SENSOR");
  lcd.setCursor(1,1);
  lcd.print("PENDETEKSI GAS");
  delay(1000);
 }
 void loop(){
  buttonState=digitalRead(buttonPin);
  if(buttonState== HIGH && lastButtonState == LOW){
    int potValue = map(potValue, 0, 1023,0,100);
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("besar gas : ");
    lcd.print(gasValue);
    lcd.print("%");
    delay(500);
  }
  lastButtonState=buttonState;
 }