Untitled

#include <WiFi.h>
#include <PubSubClient.h>

// Kredensial WiFi
const char* ssid = "Wifi_SB-II";
const char* password = "";

// Alamat server MQTT (IP atau hostname)
const char* mqtt_server = "test.mosquitto.org"; // Ganti dengan alamat broker MQTT Anda

// Objek WiFi dan MQTT
WiFiClient espClient;
PubSubClient client(espClient);

// Tentukan pin LED
const int ledPin = 18; // Ganti pin LED ke pin 18

// Fungsi callback untuk menangani pesan yang diterima
void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");

  // Menyalin payload
  for (unsigned int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();

  // Mengubah payload ke string
  String messageTemp;
  for (unsigned int i = 0; i < length; i++) {
    messageTemp += (char)payload[i];
  }

  // Menyalakan atau mematikan LED berdasarkan pesan
  if (messageTemp == "1") {
    digitalWrite(ledPin, LOW); // LED ON
  } else if (messageTemp == "0") {
    digitalWrite(ledPin, HIGH); // LED OFF
  }
}

void setup() {
  // Inisialisasi serial monitor
  Serial.begin(115200);

  // Inisialisasi pin LED
  pinMode(ledPin, OUTPUT); // Menggunakan pin 18
  digitalWrite(ledPin, HIGH); // Default LED OFF

  // Menghubungkan ke WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print("Connecting to WiFi..");
  }
  Serial.println("Connected to the WiFi network");

  // Mengatur server MQTT dan callback
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

void reconnect() {
  // Loop hingga terhubung kembali
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Membuat ID klien acak
    String clientId = "ESP8266Client-";
    clientId += String(random(0xffff), HEX);
    // Mencoba koneksi
    if (client.connect(clientId.c_str())) {
      Serial.println("connected");
      // Mempublish pesan awal
      client.publish("polines/trk/data", "hello world");
      // Subscribe ke topik
      client.subscribe("polines/trk/data");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Tunggu 5 detik sebelum mencoba lagi
      delay(5000);
    }
  }
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
}