#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16,2);
const int trigPin = 2;
const int echoPin = 3;
const int LED1 = 4;
const int LED2 = 5;
const int LED3 = 6;
const int buzzerPin = 7;
int frekuensi = 250;

long durasi;
int jarak;

void setup() {
  lcd.init();
  lcd.clear();
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("PROGRAM MULAI");
  lcd.clear();
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(buzzerPin, OUTPUT);

}

void loop() {  
  lcd.clear();
  lcd.setCursor(0, 0);
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  durasi = pulseIn(echoPin, HIGH);
  jarak = durasi * 0.034 / 2;


  if (jarak > 60) {
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, LOW);
    digitalWrite(buzzerPin, LOW);
    lcd.setCursor(0, 0);
    lcd.print("JARAK: ");
    lcd.setCursor(7, 0);
    lcd.print(jarak);
    lcd.setCursor(12,0);
     lcd.print("CM");
    lcd.setCursor(0, 1);
    lcd.print("BERBAHAYA");   
    noTone(buzzerPin);

   } else if (jarak <= 60 && jarak >= 20) {
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, HIGH);
    digitalWrite(LED3, LOW);
    digitalWrite(buzzerPin, LOW);
    lcd.setCursor(0, 0);
    lcd.print("JARAK: ");
    lcd.setCursor(12, 0);
    lcd.print(jarak);
     lcd.print("CM");
    lcd.setCursor(0, 1);
    lcd.print("Waspada");
    noTone(buzzerPin);

  } else if (jarak < 20) {
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, HIGH);
    digitalWrite(buzzerPin, LOW);
    lcd.setCursor(0, 0);
    lcd.print("JARAK: ");
    lcd.setCursor(7, 0);
    lcd.print(jarak);
    lcd.setCursor(12, 0);
     lcd.print("CM");
    lcd.setCursor(0, 1);
    lcd.print("HATI-HATI");
    tone(buzzerPin, 1000);
  }
}