Panduan Lengkap ESP32: Dari Setup Hingga Proyek IoT Pertama

// =============================================
// Proyek: Monitoring Suhu Real-time via MQTT
// BeebaneLabs - https://beebanelabs.pages.dev
// =============================================

#include "WiFi.h"
#include "PubSubClient.h"
#include "DHT.h"

// === Pin & Sensor ===
#define DHT_PIN 4
#define DHT_TYPE DHT11
#define LED_STATUS 2

// === WiFi Config ===
const char* WIFI_SSID = "NamaWiFiAnda";
const char* WIFI_PASS = "PasswordWiFi";

// === MQTT Config ===
const char* MQTT_SERVER   = "test.mosquitto.org";
const int   MQTT_PORT     = 1883;
const char* MQTT_TOPIC_DATA   = "iothub/monitoring/suhu";
const char* MQTT_TOPIC_ALERT = "iothub/monitoring/alert";
const char* MQTT_TOPIC_CMD   = "iothub/monitoring/cmd";
const char* CLIENT_ID        = "esp32_monitor_suhu_01";

// === Threshold ===
const float SUHU_BAHAYA = 35.0;   // Suhu bahaya dalam Celsius
const float SUHU_WASPADA = 30.0;  // Suhu waspada
const int   INTERVAL_KIRIM = 15000; // Kirim setiap 15 detik

// === Objek ===
DHT dht(DHT_PIN, DHT_TYPE);
WiFiClient espClient;
PubSubClient mqtt(espClient);

// === Variabel Global ===
unsigned long lastKirim = 0;
int totalPengiriman = 0;
int totalError = 0;
bool modeDebug = false;

// === Callback saat menerima pesan MQTT ===
void onMessage(char* topic, byte* payload, unsigned int length) {
  String pesan = "";
  for (unsigned int i = 0; i < length; i++) {
    pesan += (char)payload[i];
  }

  Serial.print("[CMD] Diterima di topik '");
  Serial.print(topic);
  Serial.print("': ");
  Serial.println(pesan);

  // Handle perintah sederhana
  if (pesan == "status") {
    char statusMsg[128];
    snprintf(statusMsg, sizeof(statusMsg),
      "{\"total_pengiriman\":%d,\"total_error\":%d,\"uptime\":%lu}",
      totalPengiriman, totalError, millis() / 1000);
    mqtt.publish(MQTT_TOPIC_DATA, statusMsg);
    Serial.println("[CMD] Status dikirim.");
  } else if (pesan == "debug_on") {
    modeDebug = true;
    Serial.println("[CMD] Mode debug diaktifkan.");
  } else if (pesan == "debug_off") {
    modeDebug = false;
    Serial.println("[CMD] Mode debug dinonaktifkan.");
  }
}

void setupWiFi() {
  Serial.print("WiFi: Menghubungkan ke ");
  Serial.print(WIFI_SSID);
  WiFi.mode(WIFI_STA);
  WiFi.begin(WIFI_SSID, WIFI_PASS);

  int attempt = 0;
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
    if (++attempt > 40) {
      Serial.println(" [GAGAL]");
      ESP.restart();  // Restart jika gagal
    }
  }

  Serial.println(" [OK]");
  Serial.print("IP: ");
  Serial.println(WiFi.localIP());

  // Kedipkan LED sebagai indikator WiFi terhubung
  for (int i = 0; i < 5; i++) {
    digitalWrite(LED_STATUS, HIGH);
    delay(100);
    digitalWrite(LED_STATUS, LOW);
    delay(100);
  }
}

void setupMQTT() {
  mqtt.setServer(MQTT_SERVER, MQTT_PORT);
  mqtt.setCallback(onMessage);
  mqtt.setBufferSize(256);
}

void hubungkanMQTT() {
  while (!mqtt.connected()) {
    Serial.print("MQTT: Menghubungkan...");

    // Buat pesan LWT (Last Will and Testament)
    char lwtMsg[] = "{\"status\":\"offline\"}";

    if (mqtt.connect(CLIENT_ID, MQTT_TOPIC_DATA, 1, true, lwtMsg)) {
      Serial.println(" [OK]");
      digitalWrite(LED_STATUS, HIGH);

      // Subscribe ke topik perintah
      mqtt.subscribe(MQTT_TOPIC_CMD);
      Serial.println("Subscribed ke: " + String(MQTT_TOPIC_CMD));

      // Publish status online (retained)
      mqtt.publish(MQTT_TOPIC_DATA, "{\"status\":\"online\"}", true);
    } else {
      Serial.print(" [GAGAL, rc=");
      Serial.print(mqtt.state());
      Serial.println("]");
      digitalWrite(LED_STATUS, LOW);
      delay(3000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(LED_STATUS, OUTPUT);

  Serial.println("╔════════════════════════════════════╗");
  Serial.println("║  Monitoring Suhu Real-time v1.0   ║");
  Serial.println("║  BeebaneLabs - https://beebanelabs.pages.dev       ║");
  Serial.println("╚════════════════════════════════════╝");

  dht.begin();
  setupWiFi();
  setupMQTT();
  hubungkanMQTT();
}

void loop() {
  if (!mqtt.connected()) {
    hubungkanMQTT();
  }
  mqtt.loop();

  unsigned long sekarang = millis();

  if (sekarang - lastKirim >= INTERVAL_KIRIM) {
    lastKirim = sekarang;

    // Baca sensor
    float suhu = dht.readTemperature();
    float kelembaban = dht.readHumidity();

    // Validasi pembacaan
    if (isnan(suhu) || isnan(kelembaban)) {
      totalError++;
      Serial.println("[ERROR] Pembacaan sensor gagal!");
      return;
    }

    // Hitung heat index
    float heatIndex = dht.computeHeatIndex(suhu, kelembaban, false);

    // Tentukan level status
    const char* level;
    if (suhu >= SUHU_BAHAYA) {
      level = "BAHAYA";
    } else if (suhu >= SUHU_WASPADA) {
      level = "WASPADA";
    } else {
      level = "AMAN";
    }

    // Format payload JSON
    char payload[256];
    snprintf(payload, sizeof(payload),
      "{\"suhu\":%.1f,\"kelembaban\":%.1f,\"heat_index\":%.1f,"
      "\"level\":\"%s\",\"wifi_rssi\":%d,\"uptime\":%lu,\"msg_count\":%d}",
      suhu, kelembaban, heatIndex, level,
      WiFi.RSSI(), sekarang / 1000, totalPengiriman + 1);

    // Publish data
    bool sukses = mqtt.publish(MQTT_TOPIC_DATA, payload);

    if (suhu >= SUHU_WASPADA) {
      // Kirim alert ke topik terpisah
      char alertMsg[128];
      snprintf(alertMsg, sizeof(alertMsg),
        "{\"alert\":\"SUHU %s\",\"suhu\":%.1f,\"level\":\"%s\"}",
        suhu >= SUHU_BAHAYA ? "BAHAYA" : "WASPADA",
        suhu, level);
      mqtt.publish(MQTT_TOPIC_ALERT, alertMsg);

      // Kedipkan LED untuk alert
      for (int i = 0; i < 3; i++) {
        digitalWrite(LED_STATUS, LOW);
        delay(200);
        digitalWrite(LED_STATUS, HIGH);
        delay(200);
      }
    }

    if (sukses) {
      totalPengiriman++;
      Serial.printf("[%d] Suhu: %.1f°C | RH: %.1f%% | %s\n",
        totalPengiriman, suhu, kelembaban, level);
    } else {
      totalError++;
      Serial.println("[ERROR] Gagal mengirim data!");
    }

    if (modeDebug) {
      Serial.print("[DEBUG] Payload: ");
      Serial.println(payload);
    }
  }
}