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

Servo servoku;
int echoPin = 2;
int trigPin = 3;
int buzzer = 4;

LiquidCrystal_I2C lcd(0x27, 16, 2);
String teks = "Selamat Datang DI STMIK JAYANUSA";
int indeks = 0;

void setup() {
  Serial.begin(9600);
  pinMode(echoPin, INPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(13, OUTPUT);
  lcd.begin(16, 2);
  lcd.init();
  lcd.backlight();
  servoku.attach(5);
  indeks = 0;  // Inisialisasi indeks ke 0
}

float bacaUltrasonik() {
  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 jarak = bacaUltrasonik();

  if (jarak <= 200) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("AWAS KERETA!  ");
    lcd.setCursor(0, 1);
    lcd.print("Jarak: ");
    lcd.print(jarak);
    lcd.print("cm");

    tone(buzzer, 1000);
    digitalWrite(13, HIGH);
    delay(500);
    tone(buzzer, 10);
    digitalWrite(13, LOW);
    delay(500);
    servoku.write(0);
  } else {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Tidak ADA KERETA API!  ");
    lcd.setCursor(0, 1);
    lcd.print(teks.substring(indeks, indeks + 16));  // Mengambil 16 karakter dari teks

    indeks++;
    if (indeks >= teks.length()) {
      indeks = 0;
    }

    delay(100);
    noTone(buzzer);
    servoku.write(90);
  }
}