MQTT/Ethernet reconnection sketch

Projects General Guidance
1

Hi All,
I wrote this sketch:

#include <PubSubClient.h>
#include <Ethernet.h> 

IPAddress mqtt_ip(192, 168, 1, 61);
IPAddress client_ip(192, 168, 1, 35);
IPAddress dns_gw_ip(192, 168, 1, 1);
byte mac[] = {0x11, 0x11, 0x11, 0x11, 0x11, 0x11 }; //physical mac address
const char* mqttUser = "XXXX";
const char* mqttPassword = "XXXXX";

EthernetClient espClient;
PubSubClient client(espClient);

const char *REC = "rec46/onoff"; 

//FUNZIONE CHE RICEVE I MESSAGGI MQTT
void callback(char* topic, byte* payload, unsigned int length) {
  String response;
  String topicStr = topic;   
  for (int i = 0; i < length; i++) {response += (char)payload[i];  }
  Serial.print("Message arrived [");
  Serial.print(topicStr);
  Serial.print("] ");
  Serial.println(response);
}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect("arduinonanorec46",mqttUser, mqttPassword,"rec46/will", 0, false, "offline")) {
           Serial.println("connected");
            client.subscribe(REC);    //comando rec
    } else {
      Serial.print("failed, rc="); Serial.print(client.state()); Serial.println(" try again in 5 seconds");
      delay(5000);
      }
  }
}
 
void setup()
{
  Serial.begin(115200);
  delay(100);

  Serial.println("Starting Ethernet...");
  Ethernet.begin(mac,client_ip);
  Serial.print("My IP address: ");
  Serial.println(Ethernet.localIP());
  
  client.setServer(mqtt_ip, 1883);
  client.setCallback(callback);// Initialize the callback routine
  
  delay(1000);
}
 
void loop()
{
  if (Ethernet.linkStatus() == LinkON) {if (!client.connected()) {  reconnect();  }}
  else {Serial.println("Ethernet link is down. Attempting to reconnect...");
        Ethernet.begin(mac,client_ip);
        Serial.print("My IP address: ");
        Serial.println(Ethernet.localIP());  
        delay(5000);
  }

  client.loop();
  delay(500);
}

the objective is to ensure that the card must always be connected to the ethernet network and to the mqtt broker.

I found the MQTT reconnection in various examples, but the ethernet reconnection is done by IA....

Can I have suggestions if there are errors?

2

You forgot to include the serial log in code tags of the errors