ESP8266_HIVEMQ.ino

    #include <ESP8266WiFi.h>
    #include <PubSubClient.h>
    #define wifi_ssid "TNCAP7B297F"
    #define wifi_password "xxxxxxxx"
    #define mqtt_server "192.168.1.69"
    #define mqtt_user "xxxxxxxx"
    #define mqtt_password "xxxxxxxxx"
    #define topic1 "t1"
    #define topic2 "t2"
    WiFiClient espClient;
    PubSubClient client(espClient);
    void setup() {
        Serial.begin(115200);
        setup_wifi();
        client.setServer(mqtt_server, 1883);
    }
    void setup_wifi() {
        delay(10);
        // We start by connecting to a WiFi network
        Serial.println();
        Serial.print("Connecting to ");
        Serial.println(wifi_ssid);
        WiFi.begin(wifi_ssid, wifi_password);
        while (WiFi.status() != WL_CONNECTED) {
            delay(500);
            Serial.print(".");
        }
        Serial.println("");
        Serial.println("WiFi connected");
        Serial.println("IP address: ");
        Serial.println(WiFi.localIP());
    }
    void reconnect() {
        // Loop until we're reconnected
        while (!client.connected()) {
            Serial.print("Attempting MQTT connection...");
            // Attempt to connect
            if (client.connect("TestMQTT", mqtt_user, mqtt_password)) { //* See //NOTE below
                Serial.println("connected");
            } else {
                Serial.print("failed, rc=");
                Serial.print(client.state());
                Serial.println(" try again in 5 seconds");
                // Wait 5 seconds before retrying
                delay(5000);
            }
        }
    }
    //NOTE: if a user/password is used for MQTT connection use:
//   if (client.connect("TestMQTT", mqtt_user, mqtt_password)) {
    void pubMQTT(String topic,float topic_val){
        Serial.print("Newest topic " + topic + " value:");
        Serial.println(String(topic_val).c_str());
        client.publish(topic.c_str(), String(topic_val).c_str(), true);
     }
 //   } 
    //Variables used in loop()
    long lastMsg = 0;
    float t1 = 75.5;
    float t2 = 50.5;
    void loop() {
      if (!client.connected()) {
        reconnect();
      }
      client.loop();
      //2 seconds minimum between Read Sensors and Publish
      long now = millis();
      if (now - lastMsg > 2000) {
          lastMsg = now;
          //Read Sensors (simulate by increasing the values, range:0-90)
          t1 = t1>90 ? 0 : ++t1;
          t2 = t2>90 ? 0 : ++t2;
          //Publish Values to MQTT broker
          pubMQTT(topic1,t1);
          pubMQTT(topic2,t2);
      }
    }