Trying to make a stable connection of my ESP8266 w/ Arduino Uno to a MQTT broker

Using Arduino Networking, Protocols, and Devices
1

Hello, I'm new to this forum and to this topic.

My final objective is to connect my Arduino Uno with a ESP8266 - ESP01 to a Raspberry Pi 3.

As I am new to the networking topic I thought I could make both communicate via a MQTT broker.

I found this blog that had an example to connect my ESP to a broker.

But when I do the connection it says that is connected but then it disconnects and stays on a loop connecting and disconnecting. Anyone had this kind of problem before?

If anyone wants to help, I'll but my code below:

#include <WiFiEsp.h>
#include <WiFiEspClient.h>
//#include <WiFiEspUdp.h>
//#include <WiFiClient.h>
#include <SoftwareSerial.h>
#include <PubSubClient.h>

#define DEBUG true

//Connecting to the Wifi

const char* ssid = "Gandhi";
const char* pass = "newPassw0rd";
const char* mqtt_server = "iot.eclipse.org";
const char* mqtt_topic = "ArdUnoLEDStatus";

int status = WL_IDLE_STATUS; 

IPAddress ip(192, 168, 115, 102);
IPAddress gateway(192, 168, 115, 1);
IPAddress subnet(255, 255, 255, 0);
WiFiEspClient espClient;
PubSubClient client(espClient);


SoftwareSerial esp8266(3,2);

const byte ledPin = 8;

void callback(char* topic, byte* payload, unsigned int length){

  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("]");

//  for (int i=0; i<length; i++)
//  {
//    char receivedChar = (char)payload[i];
//    Serial.print(receivedChar);
//
//    if (receivedChar == '0');
//    digitalWrite(ledPin, LOW);
//
//    if (receivedChar == '1');
//    digitalWrite(ledPin, HIGH);
//  }
  Serial.println();
  
}


void reconnect(){
    // Loop until we're reconnected

    while(!client.connected())
    {
      Serial.print("Attempting MQTT connection...");

      // Attempt to connect
      if(client.connect("ESP8266 Client"))
      {
        Serial.println("connected");
        client.subscribe(mqtt_topic); //Connecting to the topic
        delay(3000);
        Serial.println("Sending Message to Topic");
        client.publish(mqtt_topic,"Arduino Test");
        delay(3000);
      }
      else
      {
        Serial.print("failed, rc=");
        Serial.print(client.state());
        Serial.println(" try again in 5 seconds");
        delay(5000); // wait for 5 seconds
      
      }
    }
    Serial.println("I'm connected and heading out from the Reconnect function");
  }

  void setup(){
    Serial.begin(9600);
    esp8266.begin(9600);

    WiFi.init(&esp8266);

    // check for the presence of the shield
    if (WiFi.status() == WL_NO_SHIELD) {
      Serial.println("WiFi shield not present");
      // don't continue
      while (true);
    }

    // attempt to connect to WiFi network
    while (status != WL_CONNECTED) {
      Serial.print("Attempting to connect to WPA SSID: ");
      Serial.println(ssid);
      // Connect to WPA/WPA2 network
      status = WiFi.begin(ssid, pass);
    }

    
    Serial.println("You're connected to WiFi now");
    Serial.println("WiFi status :" + WiFi.status());



    Serial.println("Setting Server");
    client.setServer(mqtt_server, 1883);
    Serial.println("Callback:");
    client.setCallback(callback);

    pinMode(ledPin, OUTPUT);
  }

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

    
    client.loop();
  }

Thank you.