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

#define DHTPIN 4
#define DHTTYPE DHT22
#define RELAY_PIN 12

DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  Serial.begin(115200);
  
  pinMode(RELAY_PIN, OUTPUT);
  digitalWrite(RELAY_PIN, LOW); // Relay OFF saat awal

  dht.begin();
  lcd.init();
  lcd.backlight();
  
  lcd.setCursor(0, 0);
  lcd.print("Sistem Kontrol");
  lcd.setCursor(0, 1);
  lcd.print("Suhu Otomatis");
  delay(1500);
  lcd.clear();
}

void loop() {
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();

  // Cek jika sensor gagal membaca
  if (isnan(temp) || isnan(hum)) {
    lcd.setCursor(0, 0);
    lcd.print("Error Sensor! ");
    return;
  }

  // 1. Tampilkan Data di LCD
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temp, 1);
  lcd.print("C  ");

  lcd.setCursor(0, 1);
  lcd.print("Humi: ");
  lcd.print(hum, 1);
  lcd.print("% ");

  // 2. Kontrol Relay (Batas Suhu 30 C)
  if (temp > 30.0) {
    digitalWrite(RELAY_PIN, HIGH); // Nyalakan Pendingin
    lcd.setCursor(12, 1);
    lcd.print("[ON]");
  } else {
    digitalWrite(RELAY_PIN, LOW);  // Matikan Pendingin
    lcd.setCursor(12, 1);
    lcd.print("[OK]");
  }

  delay(2000); // Pembacaan tiap 2 detik
}