#define tombol_up 2
#define tombol_down 3
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,16,2);

int counter ;

void setup() {
  pinMode(tombol_up, INPUT_PULLUP);
  pinMode(tombol_down, INPUT_PULLUP);
  lcd.init();
  lcd.backlight();
}

void loop() {
 lcd.setCursor(0,0); lcd.print("counter =");

 if(digitalRead(tombol_up)==LOW)
 {delay(200);
   counter ++;lcd.print(counter);lcd.print(" ");
 }
 if(digitalRead(tombol_down)==LOW)
 {delay(200);
   counter --; lcd.print(counter);lcd.print(" ");
 }

}