lwMQTT testing on ESP32 with Arduino

ESP32MQTT.ino

#include <WiFi.h>
#include <MQTT.h>

const char ssid[] = "ssid";
const char password[] = "pass";

WiFiClient net;
MQTTClient client;

unsigned long lastMillis = 0;

void connect() {
  Serial.print("checking wifi...");
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(1000);
  }

  Serial.print("\nconnecting...");
  while (!client.connect("arduinoESP32")) {
    Serial.print(".");
    delay(1000);
  }

  Serial.println("\nconnected!");

  client.subscribe("/clientSub");
  // client.unsubscribe("/clientSub");
}

void messageReceived(String &topic, String &payload) {
  Serial.println("incoming: " + topic + " - " + payload);
}

void setup() {
  Serial.begin(115200);
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  // Note: Local domain names (e.g. "Computer.local" on OSX) are not supported by Arduino.
  // You need to set the IP address directly.
  client.begin("mqtt.eclipse.org", net);
  client.onMessage(messageReceived);

  connect();
}

void loop() {
  client.loop();
  delay(10);  // <- fixes some issues with WiFi stability

  if (!client.connected()) {
    connect();
  }

  // publish a message roughly every second.
  if (millis() - lastMillis > 1000) {
    lastMillis = millis();
    client.publish("/clientPub", "Hello from ESP32");
  }
}