Wokwi - Online ESP32, STM32, Arduino Simulator

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

const char * MQTTServer = "broker.emqx.io";
const char * MQTT_Topic = "testtopic/batden1";

// Tạo ID ngẫu nhiên tại: https://www.guidgen.com/
const char * MQTT_ID = "eecf5f88-5a58-4c56-9277-74d5510d11fc";
int Port = 1883;

WiFiClient espClient;
PubSubClient client(espClient);
const int ledPin = 2;

void WIFIConnect() {
  Serial.println("Connecting to SSID: Wokwi-GUEST");
  WiFi.begin("Wokwi-GUEST", "");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("WiFi connected");
  Serial.print(", IP address: ");
  Serial.println(WiFi.localIP());
}

void MQTT_Reconnect() {
  while (!client.connected()) {
    if (client.connect(MQTT_ID)) {
      Serial.print("MQTT Topic: ");
      Serial.print(MQTT_Topic);
      Serial.print(" connected");
      client.subscribe(MQTT_Topic);
      Serial.println("");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void callback(char* topic, byte* message, unsigned int length) {
  Serial.print("Message arrived on topic: ");
  Serial.println(topic);
  Serial.print("Message: ");
  String stMessage;

  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    stMessage += (char)message[i];
  }
  Serial.println();
  if (stMessage == "on") {
    digitalWrite(ledPin, HIGH);
  }
  else if (stMessage == "off") {
    digitalWrite(ledPin, LOW);
  }
}

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

  WIFIConnect();
  client.setServer(MQTTServer, Port);
  client.setCallback(callback);
  pinMode(ledPin, OUTPUT);
}

void loop() {
  delay(10);
  if (!client.connected()) {
    MQTT_Reconnect();
  }
  client.loop();
}
/*
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <script
      src="https://cdnjs.cloudflare.com/ajax/libs/paho-mqtt/1.0.1/mqttws31.min.js"
      type="text/javascript"
    ></script>
    <script
      src="https://code.jquery.com/jquery-3.6.1.min.js"
      type="text/javascript"
    ></script>
    <style>
      body {
        font-family: Arial, sans-serif;
        text-align: center;
        padding-top: 50px;
      }

      .anh {
        width: 80px;
        margin: 10px;
        cursor: pointer;
        display: inline-block;
      }

      button {
        padding: 10px 20px;
        margin: 10px;
        cursor: pointer;
      }
    </style>
  </head>
  <body>
    <img class="anh" src="27112023144221.jpg" alt="LED Image" />
    <div class="thongbao">Đang Tắt</div>
  </body>
</html>

<script>
  var anh_bat = "27112023144221.jpg";
  var anh_tat = "wdoq93jk.png";
  $(".anh").click(function () {
    var anhht = $(".anh").attr("src");
    if (anhht == anh_bat) {
      $(".anh").attr("src", anh_tat);
      $(".thongbao").text("Đang Tắt");

      message = new Paho.MQTT.Message("off");
      message.destinationName = "DHTtri";
      client.send(message);
    } else {
      $(".anh").attr("src", anh_bat);
      $(".thongbao").text("Đang Bật");

      message = new Paho.MQTT.Message("on");
      message.destinationName = "DHTtri";
      client.send(message);
    }
  });

  client = new Paho.MQTT.Client(
    "broker.emqx.io",
    Number(8083),
    "8c884929-2392-4806-9b70-686acaea3f89"
  );

  client.onConnectionLost = onConnectionLost;
  client.onMessageArrived = onMessageArrived;

  client.connect({ onSuccess: onConnect });

  function onConnect() {
    console.log("onConnect");
    // client.subscribe("World");
  }

  function onConnectionLost(responseObject) {
    if (responseObject.errorCode !== 0) {
      console.log("onConnectionLost:" + responseObject.errorMessage);
    }
  }

  function onMessageArrived(message) {
    console.log("onMessageArrived:" + message.payloadString);
  }
</script>
*/