MQTT test with emqx free broker

esp32-mqtt-emqx.ino

@@ -6,10 +6,19 @@
 #include <PubSubClient.h>
 
 // WiFi configuration
-const char *ssid = "sedeam"; // WiFi name
-const char *password = "Sede@m2025";  // WiFi password
+const char *ssid = "Haus2.4G"; // WiFi name
+const char *password = "7476Haus#CB2040$";  // WiFi password
 WiFiClient espClient;
 
+// mqtt brocker:
+const char *mqttBrocker = "broker.emqx.io";
+const char *topic = "esp32/test";
+const char *mqttUsername = "emqx";
+const char *mqttPassword = "public";
+const int mqttPort = 1883;
+PubSubClient client(espClient);
+
+
 void setup(){
   //serial communication
   Serial.begin(115200);
@@ -20,8 +29,38 @@ void setup(){
     Serial.println(ssid); 
   }
   Serial.println("Connection done.");
+  //connecting to a mqtt brocker:
+  client.setServer(mqttBrocker, mqttPort);
+  client.setCallback(callback);
+  while(!client.connected()){
+    String clientID = "esp32-gmarx-";
+    clientID += String(WiFi.macAddress());
+    Serial.printf("The %s tries to connect to mqtt borcker...\n",clientID.c_str());
+    if(client.connect(clientID.c_str(), mqttUsername, mqttPassword)){
+      Serial.println("mqtt brocker connected");
+    }
+    else {
+      Serial.print("mqtt connection failed");
+      Serial.println(client.state());
+      delay(2000);
+    }
+  }
+  //once connected publish and suscribe:
+  client.publish(topic, "Hi EMQX broker I'm a ESP32 :)");
+  client.subscribe(topic);
 }
 
 void loop(){
-  
+  client.loop();
+}
+
+void callback(char *topic, byte *payload, unsigned int length){
+  Serial.print("Message recived in topic: ");
+  Serial.println(topic);
+  Serial.print("The message is: ");
+  for(int i=0;i<length; i++){
+    Serial.print((char) payload[i]);
+  }
+  Serial.println();
+  Serial.println("-+-+-+End+-+-+-+");
 }