pr/306 Using a mDNS

README.md

@@ -3,7 +3,7 @@
 ![Build with PlatformIO](https://github.com/marvinroger/async-mqtt-client/workflows/Build%20with%20Platformio/badge.svg)
 ![cpplint](https://github.com/marvinroger/async-mqtt-client/workflows/cpplint/badge.svg)
 
-An Arduino for ESP8266 and ESP32 asynchronous [MQTT](http://mqtt.org/) client implementation, built on [me-no-dev/ESPAsyncTCP (ESP8266)](https://github.com/me-no-dev/ESPAsyncTCP) | [me-no-dev/AsyncTCP (ESP32)](https://github.com/me-no-dev/AsyncTCP) .
+An Arduino for ESP8266 and ESP32 asynchronous [MQTT](http://mqtt.org/) client implementation, built on [me-no-dev/ESPAsyncTCP (ESP8266)](https://github.com/me-no-dev/ESPAsyncTCP) | [me-no-dev/AsyncTCP (ESP32)](https://github.com/me-no-dev/AsyncTCP).
 
 ## Features
 
@@ -13,7 +13,8 @@ An Arduino for ESP8266 and ESP32 asynchronous [MQTT](http://mqtt.org/) client im
 * Publish at QoS 0, 1 and 2
 * SSL/TLS support
 * Available in the [PlatformIO registry](http://platformio.org/lib/show/346/AsyncMqttClient)
+* **New:** Option to discover the MQTT server by searching for the service `_mqtt` over the `_tcp` port.
 
 ## Requirements, installation and usage
 
-The project is documented in the [/docs folder](docs).
+The project is documented in the [/docs folder](docs).

examples/FullyFeatured-ESP32/FullyFeatured-ESP32.ino

@@ -2,133 +2,132 @@
 This example uses FreeRTOS softwaretimers as there is no built-in Ticker library
 */
 
-
 #include <WiFi.h>
 extern "C" {
-	#include "freertos/FreeRTOS.h"
-	#include "freertos/timers.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/timers.h"
 }
 #include <AsyncMqttClient.h>
 
 #define WIFI_SSID "yourSSID"
 #define WIFI_PASSWORD "yourpass"
 
-#define MQTT_HOST IPAddress(192, 168, 1, 10)
-#define MQTT_PORT 1883
+const char* mqttServiceName = "_mqtt";
+const char* protocol = "_tcp";
 
 AsyncMqttClient mqttClient;
 TimerHandle_t mqttReconnectTimer;
 TimerHandle_t wifiReconnectTimer;
 
 void connectToWifi() {
-  Serial.println("Connecting to Wi-Fi...");
-  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
+    Serial.println("Connecting to Wi-Fi...");
+    WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
 }
 
 void connectToMqtt() {
-  Serial.println("Connecting to MQTT...");
-  mqttClient.connect();
+    Serial.println("Connecting to MQTT...");
+    mqttClient.connect();
 }
 
 void WiFiEvent(WiFiEvent_t event) {
     Serial.printf("[WiFi-event] event: %d\n", event);
-    switch(event) {
-    case SYSTEM_EVENT_STA_GOT_IP:
-        Serial.println("WiFi connected");
-        Serial.println("IP address: ");
-        Serial.println(WiFi.localIP());
-        connectToMqtt();
-        break;
-    case SYSTEM_EVENT_STA_DISCONNECTED:
-        Serial.println("WiFi lost connection");
-        xTimerStop(mqttReconnectTimer, 0); // ensure we don't reconnect to MQTT while reconnecting to Wi-Fi
-        xTimerStart(wifiReconnectTimer, 0);
-        break;
+    switch (event) {
+        case SYSTEM_EVENT_STA_GOT_IP:
+            Serial.println("WiFi connected");
+            Serial.println("IP address: ");
+            Serial.println(WiFi.localIP());
+            connectToMqtt();
+            break;
+        case SYSTEM_EVENT_STA_DISCONNECTED:
+            Serial.println("WiFi lost connection");
+            xTimerStop(mqttReconnectTimer, 0);  // ensure we don't reconnect to MQTT while reconnecting to Wi-Fi
+            xTimerStart(wifiReconnectTimer, 0);
+            break;
     }
 }
 
 void onMqttConnect(bool sessionPresent) {
-  Serial.println("Connected to MQTT.");
-  Serial.print("Session present: ");
-  Serial.println(sessionPresent);
-  uint16_t packetIdSub = mqttClient.subscribe("test/lol", 2);
-  Serial.print("Subscribing at QoS 2, packetId: ");
-  Serial.println(packetIdSub);
-  mqttClient.publish("test/lol", 0, true, "test 1");
-  Serial.println("Publishing at QoS 0");
-  uint16_t packetIdPub1 = mqttClient.publish("test/lol", 1, true, "test 2");
-  Serial.print("Publishing at QoS 1, packetId: ");
-  Serial.println(packetIdPub1);
-  uint16_t packetIdPub2 = mqttClient.publish("test/lol", 2, true, "test 3");
-  Serial.print("Publishing at QoS 2, packetId: ");
-  Serial.println(packetIdPub2);
+    Serial.println("Connected to MQTT.");
+    Serial.print("Session present: ");
+    Serial.println(sessionPresent);
+    uint16_t packetIdSub = mqttClient.subscribe("test/lol", 2);
+    Serial.print("Subscribing at QoS 2, packetId: ");
+    Serial.println(packetIdSub);
+    mqttClient.publish("test/lol", 0, true, "test 1");
+    Serial.println("Publishing at QoS 0");
+    uint16_t packetIdPub1 = mqttClient.publish("test/lol", 1, true, "test 2");
+    Serial.print("Publishing at QoS 1, packetId: ");
+    Serial.println(packetIdPub1);
+    uint16_t packetIdPub2 = mqttClient.publish("test/lol", 2, true, "test 3");
+    Serial.print("Publishing at QoS 2, packetId: ");
+    Serial.println(packetIdPub2);
 }
 
 void onMqttDisconnect(AsyncMqttClientDisconnectReason reason) {
-  Serial.println("Disconnected from MQTT.");
+    Serial.println("Disconnected from MQTT.");
 
-  if (WiFi.isConnected()) {
-    xTimerStart(mqttReconnectTimer, 0);
-  }
+    if (WiFi.isConnected()) {
+        xTimerStart(mqttReconnectTimer, 0);
+    }
 }
 
 void onMqttSubscribe(uint16_t packetId, uint8_t qos) {
-  Serial.println("Subscribe acknowledged.");
-  Serial.print("  packetId: ");
-  Serial.println(packetId);
-  Serial.print("  qos: ");
-  Serial.println(qos);
+    Serial.println("Subscribe acknowledged.");
+    Serial.print("  packetId: ");
+    Serial.println(packetId);
+    Serial.print("  qos: ");
+    Serial.println(qos);
 }
 
 void onMqttUnsubscribe(uint16_t packetId) {
-  Serial.println("Unsubscribe acknowledged.");
-  Serial.print("  packetId: ");
-  Serial.println(packetId);
+    Serial.println("Unsubscribe acknowledged.");
+    Serial.print("  packetId: ");
+    Serial.println(packetId);
 }
 
 void onMqttMessage(char* topic, char* payload, AsyncMqttClientMessageProperties properties, size_t len, size_t index, size_t total) {
-  Serial.println("Publish received.");
-  Serial.print("  topic: ");
-  Serial.println(topic);
-  Serial.print("  qos: ");
-  Serial.println(properties.qos);
-  Serial.print("  dup: ");
-  Serial.println(properties.dup);
-  Serial.print("  retain: ");
-  Serial.println(properties.retain);
-  Serial.print("  len: ");
-  Serial.println(len);
-  Serial.print("  index: ");
-  Serial.println(index);
-  Serial.print("  total: ");
-  Serial.println(total);
+    Serial.println("Publish received.");
+    Serial.print("  topic: ");
+    Serial.println(topic);
+    Serial.print("  qos: ");
+    Serial.println(properties.qos);
+    Serial.print("  dup: ");
+    Serial.println(properties.dup);
+    Serial.print("  retain: ");
+    Serial.println(properties.retain);
+    Serial.print("  len: ");
+    Serial.println(len);
+    Serial.print("  index: ");
+    Serial.println(index);
+    Serial.print("  total: ");
+    Serial.println(total);
 }
 
 void onMqttPublish(uint16_t packetId) {
-  Serial.println("Publish acknowledged.");
-  Serial.print("  packetId: ");
-  Serial.println(packetId);
+    Serial.println("Publish acknowledged.");
+    Serial.print("  packetId: ");
+    Serial.println(packetId);
 }
 
 void setup() {
-  Serial.begin(115200);
-  Serial.println();
-  Serial.println();
+    Serial.begin(115200);
+    Serial.println();
+    Serial.println();
 
-  mqttReconnectTimer = xTimerCreate("mqttTimer", pdMS_TO_TICKS(2000), pdFALSE, (void*)0, reinterpret_cast<TimerCallbackFunction_t>(connectToMqtt));
-  wifiReconnectTimer = xTimerCreate("wifiTimer", pdMS_TO_TICKS(2000), pdFALSE, (void*)0, reinterpret_cast<TimerCallbackFunction_t>(connectToWifi));
+    mqttReconnectTimer = xTimerCreate("mqttTimer", pdMS_TO_TICKS(2000), pdFALSE, (void*)0, reinterpret_cast<TimerCallbackFunction_t>(connectToMqtt));
+    wifiReconnectTimer = xTimerCreate("wifiTimer", pdMS_TO_TICKS(2000), pdFALSE, (void*)0, reinterpret_cast<TimerCallbackFunction_t>(connectToWifi));
 
-  WiFi.onEvent(WiFiEvent);
+    WiFi.onEvent(WiFiEvent);
 
-  mqttClient.onConnect(onMqttConnect);
-  mqttClient.onDisconnect(onMqttDisconnect);
-  mqttClient.onSubscribe(onMqttSubscribe);
-  mqttClient.onUnsubscribe(onMqttUnsubscribe);
-  mqttClient.onMessage(onMqttMessage);
-  mqttClient.onPublish(onMqttPublish);
-  mqttClient.setServer(MQTT_HOST, MQTT_PORT);
+    mqttClient.onConnect(onMqttConnect);
+    mqttClient.onDisconnect(onMqttDisconnect);
+    mqttClient.onSubscribe(onMqttSubscribe);
+    mqttClient.onUnsubscribe(onMqttUnsubscribe);
+    mqttClient.onMessage(onMqttMessage);
+    mqttClient.onPublish(onMqttPublish);
+    mqttClient.setServer(mqttServiceName, protocol);
 
-  connectToWifi();
+    connectToWifi();
 }
 
 void loop() {