feat(homeassistant): enable homeassistant discovery

refactor(mqtt): use arduino json for overrides

doc(homeassistant): some remarks to homeassistant integration

refactor(discovery): various items from test

AquaMQTT/include/Version.h

@@ -0,0 +1,4 @@
+namespace aquamqtt
+{
+constexpr char VERSION[] = "v1.4.0";
+}

AquaMQTT/include/config/Configuration.h

@@ -34,6 +34,17 @@ constexpr char timeZoneInfo[] = "CET-1CEST,M3.5.0,M10.5.0/3";  // Europe/Berlin
  */
 constexpr char ntpServer[] = "pool.ntp.org";
 
+/**
+ * Enable HomeAssistant MQTT Discovery Mode
+ */
+constexpr bool ENABLE_HOMEASSISTANT_DISCOVERY_MODE = true;
+
+/**
+ * Homeassistant MQTT Discovery Prefix
+ * https://www.home-assistant.io/integrations/mqtt/#discovery-topic
+ */
+constexpr char haDiscoveryPrefix[] = "homeassistant/";
+
 /**
  * The OperationMode which is used for AquaMqtt. Refer to EOperationMode
  */
@@ -104,8 +115,8 @@ constexpr float ABSENCE_WATER_TEMPERATURE = 20.0;
  */
 constexpr uint32_t WATCHDOG_TIMEOUT_MS    = 60000;
 constexpr uint16_t WIFI_RECONNECT_CYCLE_S = 10;
-constexpr uint8_t  MQTT_MAX_TOPIC_SIZE    = 80;
-constexpr uint8_t  MQTT_MAX_PAYLOAD_SIZE  = 255;
+constexpr uint16_t MQTT_MAX_TOPIC_SIZE    = 255;
+constexpr uint16_t MQTT_MAX_PAYLOAD_SIZE  = 1024;
 
 /**
  * Pin assignments for AquaMQTT Board Rev 1.0

AquaMQTT/include/config/ExampleConfiguration.h

@@ -12,9 +12,10 @@ constexpr char     brokerAddr[]     = "192.168.188.1";
 constexpr uint16_t brokerPort       = 1883;
 constexpr char     brokerClientId[] = "aquamqtt";
 // leave blank if your broker does not require a username/password
-constexpr char brokerUser[]     = "";
-constexpr char brokerPassword[] = "";
-constexpr char mqttPrefix[]     = "";
+constexpr char brokerUser[]        = "";
+constexpr char brokerPassword[]    = "";
+constexpr char mqttPrefix[]        = "";
+constexpr char heatpumpModelName[] = "Atlantic Explorer v4";
 
 }  // namespace config