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

#define TRIG_PIN 2
#define ECHO_PIN 3

const int merah = 22;
const int kuning = 23;
const int hijau = 24;

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(merah, OUTPUT);
  pinMode(kuning, OUTPUT);
  pinMode(hijau, OUTPUT);

  lcd.begin(16,2);
  lcd.init();
  lcd.backlight();
}

void loop() {
  long durasi, jarak;
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);

  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  durasi = pulseIn(ECHO_PIN, HIGH);
  jarak = durasi * 0.034 / 2;

  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(jarak);
  lcd.print("cm");

  if (jarak <= 5) {
    digitalWrite(merah, HIGH);
    digitalWrite(kuning, LOW);
    digitalWrite(hijau, LOW);
  } else if (jarak > 5 && jarak <= 15) {
    digitalWrite(merah, LOW);
    digitalWrite(kuning, HIGH);
    digitalWrite(hijau, LOW);
  } else {
    digitalWrite(merah, LOW);
    digitalWrite(kuning, LOW);
    digitalWrite(hijau, HIGH);
  }

  delay(500);
}