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

#define trigPin 9
#define echoPin 10
#define buzzerPin 8

LiquidCrystal_I2C lcd(0x27, 16, 2); // Alamat I2C bisa disesuaikan (umum: 0x27 atau 0x3F)

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  
  lcd.init();                      // initialize the lcd 
  lcd.init();
  // Print a message to the LCD.
  lcd.backlight();
  lcd.setCursor(3,0);
  lcd.print("Alarm Parkir");
  delay(1000);
  lcd.clear();
}

void loop() {
  long duration;
  float distance;

  // Kirim sinyal trigger
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin,LOW);

  // Baca echo
  duration = pulseIn(echoPin, HIGH);
  distance = (duration * 0.0343) / 2;

  // Tampilkan di LCD
  lcd.setCursor(0, 0);
  lcd.print("Jarak: ");
  lcd.print(distance, 1);
  lcd.print(" cm   ");

  // Alarm berdasarkan jarak
  if (distance < 10) {
    tone(buzzerPin, 1000);
    delay(100);
    noTone(buzzerPin);
    delay(100);
  } else if (distance < 0) {
    tone(buzzerPin, 1000);
    delay(300);
    noTone(buzzerPin);
    delay(300);
  } else if (distance < 30) {
    tone(buzzerPin, 1000);
    delay(500);
    noTone(buzzerPin);
    delay(500);
  } else {
    noTone(buzzerPin);
  }

  delay(100);
}