/****************************************************
 * SISTEM PENYIRAMAN OTOMATIS BERBASIS PID
 * Input  : DHT22 (Kelembaban)
 * Output : PWM LED (Simulasi Pompa)
 * Board  : ESP32
 ****************************************************/

#include <DHT.h>
#include <PID_v1_bc.h>

// =====================
// PIN KONFIGURASI
// =====================
#define DHTPIN 22        // Pin data DHT22
#define DHTTYPE DHT22

#define LED_PIN 18      // PWM LED (simulasi pompa)

// =====================
// OBJEK SENSOR
// =====================
DHT dht(DHTPIN, DHTTYPE);

// =====================
// VARIABEL PID
// =====================
double setpoint = 60.0;     // Target kelembaban (%)
double input;               // Kelembaban aktual
double output;              // PWM output (0–255)

// Parameter PID (stabil, hasil tuning simulasi)
double Kp = 2.2;
double Ki = 0.45;
double Kd = 0.1;

// Objek PID
PID myPID(&input, &output, &setpoint, Kp, Ki, Kd, DIRECT);

// =====================
// SETUP
// =====================
void setup() {
  Serial.begin(115200);
  dht.begin();

  pinMode(LED_PIN, OUTPUT);

  // Inisialisasi PID
  myPID.SetMode(AUTOMATIC);
  myPID.SetOutputLimits(0, 255);   // PWM range
  myPID.SetSampleTime(100);        // 100 ms

  Serial.println("=== SISTEM PENYIRAMAN OTOMATIS PID ===");
}

// =====================
// LOOP
// =====================
void loop() {
  // Baca kelembaban dari DHT22
  float humidity = dht.readHumidity();

  // Validasi pembacaan sensor
  if (isnan(humidity)) {
    Serial.println("Gagal membaca DHT22!");
    delay(1000);
    return;
  }

  // Masukkan ke variabel PID
  input = humidity;

  // Hitung PID
  myPID.Compute();

  // Keluarkan PWM ke LED (simulasi pompa)
  analogWrite(LED_PIN, (int)output);

  // =====================
  // SERIAL MONITOR
  // =====================
  Serial.print("Kelembaban: ");
  Serial.print(input);
  Serial.print(" % | PWM Pompa: ");
  Serial.print(output);
  Serial.print(" | Setpoint: ");
  Serial.println(setpoint);

  delay(500);
}