Add LWT for MQTT and AMQTT

- Add LWT for MQTT and AMQTT, address https://github.com/toblum/McLighting/issues/340

Arduino/McLighting/McLighting.ino

@@ -492,6 +492,7 @@ void setup() {
       amqttClient.setServer(mqtt_host, atoi(mqtt_port));
       if (mqtt_user != "" or mqtt_pass != "") amqttClient.setCredentials(mqtt_user, mqtt_pass);
       amqttClient.setClientId(mqtt_clientid);
+      amqttClient.setWill(mqtt_will_topic.c_str(), 2, true, mqtt_will_payload, 0);
 
       connectToMqtt();
     }

Arduino/McLighting/definitions.h

@@ -62,6 +62,9 @@ uint32_t autoParams[][4] = {  // color, speed, mode, duration (milliseconds)
 };
 
 #if defined(ENABLE_MQTT) or defined(ENABLE_AMQTT)
+  const String mqtt_will_topic = String(HOSTNAME) + "/status";
+  const char mqtt_will_payload[] = "ONLINE";
+
   #ifdef ENABLE_MQTT
     #define MQTT_MAX_PACKET_SIZE 512
     #define MQTT_MAX_RECONNECT_TRIES 4

Arduino/McLighting/request_handlers.h

@@ -996,7 +996,7 @@ void checkForRequests() {
       mqtt_reconnect_retries++;
       DBG_OUTPUT_PORT.printf("Attempting MQTT connection %d / %d ...\n", mqtt_reconnect_retries, MQTT_MAX_RECONNECT_TRIES);
       // Attempt to connect
-      if (mqtt_client.connect(mqtt_clientid, mqtt_user, mqtt_pass)) {
+      if (mqtt_client.connect(mqtt_clientid, mqtt_user, mqtt_pass, mqtt_will_topic.c_str(), 2, true, mqtt_will_payload, true)) {
         DBG_OUTPUT_PORT.println("MQTT connected!");
         // Once connected, publish an announcement...
         char * message = new char[18 + strlen(HOSTNAME) + 1];

Arduino/McLighting/version_info.ino

@@ -73,4 +73,5 @@
  * - Added alternative way to send large messages using PubSubClient
  * - Bump PIO core to 2.0.1
  * - Send HA state on MQTT connect, address https://github.com/toblum/McLighting/issues/349
+ * - Add LWT for MQTT and AMQTT, address https://github.com/toblum/McLighting/issues/340
  */

platformio.ini

@@ -45,6 +45,7 @@ lib_deps =
   WebSockets
   ESPAsyncE131
   ESPAsyncUDP
+  PubSubClient
 
 [env:esp01_1m]
 board = esp01_1m