#include <LiquidCrystal_I2C.h>



LiquidCrystal_I2C lcd(0x27,16,2);

int echoPin = 6;
int trigPin = 5;
int ledR = 2;
int ledY = 3;
int ledG = 4;

void setup() {
  pinMode(echoPin, INPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(ledR, OUTPUT);
  pinMode(ledY, OUTPUT);
  pinMode(ledG, OUTPUT);
  lcd.begin(16,2);
  lcd.backlight();
}

float ultrasonik() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  int durasi = pulseIn(echoPin, HIGH);
  return durasi * 0.034 / 2;
}

void loop() {
  float sensor = ultrasonik();
  lcd.setCursor(0, 0);
  if(sensor > 60) {
    digitalWrite(ledG, HIGH);
    digitalWrite(ledR, LOW);
    digitalWrite(ledY, LOW);
    lcd.print("HIJAU");
  }

  else if(sensor <= 60 && sensor >= 10) {
    digitalWrite(ledG, LOW);
    digitalWrite(ledR, LOW);
    digitalWrite(ledY, HIGH);
    lcd.print("KUNING");
  }

  else if(sensor < 10) {
    digitalWrite(ledG, LOW);
    digitalWrite(ledR, HIGH);
    digitalWrite(ledY, LOW);
    lcd.print("MERAH");
  }

}