client.connect always fails with -2

[kevinyea]

Network with 2 MQTT servers (one on a Mac, one on a pi). Client on iphone can pub/sub to both; each can pub and sub to the other so doesn't seem to be MQTT side. Everything MQTT_VERSION_3_1_1

Can ping Heltec_WiFi_Lora32 from MQTT servers connection established. DHCP issues same IP each time.

Note: On Arduino/PlatformIO Ethernet.h conflicts with SPI.h, so used Internet2 package (is this ok?)

Any clue how to overcome problem? Thanks

#include <WiFi.h>
#include <PubSubClient.h>
#include "SPI.h"
#include <Ethernet2.h>
#include "SSD1306Wire.h"
#include <Wire.h>

const char* ssid = "HUAWEI_T222";
const char* password = "ABCDEF10293222";
const char* device_id = "dev01";
IPAddress server(192,168,8,102);  // MQTT server (Mac)
WiFiClient espClient;
SSD1306Wire display(0x3c, 4, 15);
String rssi = "RSSI --";
String packSize = "--";
String packet ;
IPAddress ipIP; // dhcp ip ends 101
EthernetClient ethClient;
PubSubClient client(ethClient);

void connectToNetwork() {
  WiFi.begin(ssid, password);
  delay(1500);

  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connected to WiFi..");  // works
    delay(500);
  }

  Serial.println("Connected to network");
  ipIP =  WiFi.localIP() ;
  Serial.println(ipIP);
}

void connectToMQTTServer() {
  Serial.println("Connecting to MQTT Server");
  client.setServer(server, 1883);
  client.setClient(ethClient);

   while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect(device_id)) { // fails always
      Serial.println("connected");
      // Once connected, publish an announcement...
      client.publish("garden/light","works");
    } else {
      Serial.print("failed, rc= ");  // always fails with -2
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  while (!Serial);
//  WiFi.mode(WIFI_STA); // doesn't help
  connectToNetwork();
  connectToMQTTServer();
  Serial.println("init ok");
}

void loop() {
  Serial.println("In publishing loop");
  display.clear();
  display.setTextAlignment(TEXT_ALIGN_LEFT);
  display.setFont(ArialMT_Plain_10);
  int p = client.publish ("garden/light", "On");
  if (p == true)
//   display.drawString(40, 30, "Published");
  else
//    display.drawString(40, 30, "Pub Failed");
//  display.display();

}

[Najab]

Because you are using WiFi and for PubSubClient client(ethClient) you are using EthernetClient ethClient so change it with WiFiClient espClient so your PubSubClient client(espClient) is now it will work.