#include <Arduino.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>


LiquidCrystal_I2C lcd(0x27, 16, 2);


const int trigPin =13;
const int echoPin = 12;


const int redPin = 2;
const int yellowPin = 26;
const int greenPin = 32;


const int buzzerPin = 14;


long duration;
int distance;

void setup(){


  pinMode(redPin, OUTPUT);
  pinMode(yellowPin, OUTPUT);
  pinMode(greenPin, OUTPUT);


Serial.begin(9600);


pinMode (trigPin, OUTPUT);
pinMode (echoPin, INPUT);

 
  lcd.init();
  lcd.backlight();

  
  pinMode(buzzerPin,OUTPUT);



}


void loop(){

digitalWrite(trigPin,LOW) ;
delayMicroseconds(2) ;
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW) ;


duration =pulseIn (echoPin, HIGH);



distance = duration * 0.034 / 2;


Serial.print("Jarak: ");
Serial.print(distance);
Serial.println("cm");


lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Jarak: ");
lcd.print(distance);
lcd.print(" cm");

  
  if (distance > 30) {
    digitalWrite(greenPin, HIGH);
    digitalWrite(redPin, LOW);
    digitalWrite(yellowPin, LOW);
  } else if (distance >= 14 && distance <= 29) {
    digitalWrite(greenPin, LOW);
    digitalWrite(redPin, LOW);
    digitalWrite(yellowPin, HIGH);
  } else if (distance >= 0 && distance < 14) {
    digitalWrite(greenPin, LOW);
    digitalWrite(redPin, HIGH);
    digitalWrite(yellowPin, LOW);
  } 

  
  if (distance < 15){
    tone(buzzerPin,1000);
  }else{
    noTone(buzzerPin);
  }

delay(500);
}