// data lcd
#include <LiquidCrystal_I2C.h>

// LCD I2C
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Identifikasi pin
#define TRIG_PIN 17
#define ECHO_PIN 16

#define LED_HIJAU 26
#define LED_KUNING 25
#define LED_MERAH 33
#define BUZZER 23

long duration;
float distance;

void setup() {
  Serial.begin(115200);

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  pinMode(LED_HIJAU, OUTPUT);
  pinMode(LED_KUNING, OUTPUT);
  pinMode(LED_MERAH, OUTPUT);
  pinMode(BUZZER, OUTPUT);

  // LCD
  lcd.init();
  lcd.backlight();

  lcd.setCursor(0, 0);
  lcd.print("DETEKSI BANJIR");
  lcd.setCursor(0, 1);
  lcd.print("Memulai...");
  delay(2000);

  lcd.clear();
}

void loop() {

  // Pemicu sensor ultrasonic
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);

  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);

  digitalWrite(TRIG_PIN, LOW);

  // Membaca pantulan
  duration = pulseIn(ECHO_PIN, HIGH, 30000);

  // Menghitung jarak
  if (duration == 0) {
    distance = 0;
  } else {
    distance = duration * 0.034 / 2;
  }

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

  // Reset LED
  digitalWrite(LED_HIJAU, LOW);
  digitalWrite(LED_KUNING, LOW);
  digitalWrite(LED_MERAH, LOW);

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

  // Logika banjir
  if (distance > 151) {

    // AMAN
    digitalWrite(LED_HIJAU, HIGH);
    noTone(BUZZER);

    Serial.println("STATUS: AMAN");

    lcd.setCursor(0, 1);
    lcd.print("STATUS: AMAN");

  } 
  else if (distance > 71 && distance <= 151) {

    // WASPADA
    digitalWrite(LED_KUNING, HIGH);
    tone(BUZZER, 500);

    Serial.println("STATUS: WASPADA");

    lcd.setCursor(0, 1);
    lcd.print("STATUS: WASPADA");

  } 
  else {

    // BAHAYA
    digitalWrite(LED_MERAH, HIGH);
    tone(BUZZER, 2000);

    Serial.println("STATUS: BAHAYA!");

    lcd.setCursor(0, 1);
    lcd.print("STATUS: BANJIR!");

  }

  delay(1500);
}