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


LiquidCrystal_I2C lcd(0x27, 16, 2);


const int trigPin = 9;
const int echoPin = 8;


const int ledPin = 10;
const int buzzerPin = 11;


long duration;
float distance;
const float safeDistance = 50.0; 

void setup() {
  
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);

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

  
  Serial.begin(9600);

 
  lcd.setCursor(0, 0);
  lcd.print("Longsor Detector");
  lcd.setCursor(0, 1);
  lcd.print("Initializing...");
  delay(2000);
  lcd.clear();
}

void loop() {
  
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  
  duration = pulseIn(echoPin, HIGH);

  
  distance = (duration * 0.034) / 2;

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

  
  if (distance < safeDistance) {
    lcd.setCursor(0, 1);
    lcd.print("Bahaya Longsor!");
    digitalWrite(ledPin, HIGH);
    digitalWrite(buzzerPin, HIGH);
  } else {
    lcd.setCursor(0, 1);
    lcd.print("Status: Aman    ");
    digitalWrite(ledPin, LOW);
    digitalWrite(buzzerPin, LOW);
  }

  
  delay(500);
}