Add Home Assistant MQTT room presence support (ESP32 only) (#294)

* Add Home Assistant MQTT room presence support

ESP32 only

ZgatewayBT.ino

@@ -126,6 +126,28 @@ Thanks to wolass https://github.com/wolass for suggesting me HM 10 and dinosd ht
                     boolean result = process_data(pos - 26,service_data,mac);
                   }
                 }
+            #ifdef roomPresence
+              StaticJsonBuffer<200> jsonBuffer;
+              JsonObject& HomePresence = jsonBuffer.createObject();
+              trc("BLE id :");    
+              String id = advertisedDevice.getAddress().toString().c_str();
+              trc(id);
+              HomePresence["id"] = id;
+              trc("BLE Name :");
+              String name = advertisedDevice.getName().c_str();
+              trc(name);
+              HomePresence["name"] = name;
+              trc("BLE DISTANCE :");
+              double BLErssi = advertisedDevice.getRSSI();
+              double ratio = BLErssi/-59;
+              double distance = (0.89)* pow(ratio,7.7095) + 0.11;  
+              HomePresence["distance"] = distance;
+              HomePresence["rssi"] = BLErssi;
+              trc(distance);
+             char JSONmessageBuffer[100];
+             HomePresence.printTo(JSONmessageBuffer, sizeof(JSONmessageBuffer));
+             client.publish(subjectHomePresence,JSONmessageBuffer);
+           #endif
             }
           }
       };

config_BT.h

@@ -42,6 +42,13 @@
 #define delimiter "4f4b2b444953413a"
 #define delimiter_length 16
 
+/*-------------------HOME ASSISTANT ROOM PRESENCE !!! ESP32 only !!!!----------------------*/
+#define roomPresence //Uncomment to enable 
+#ifdef roomPresence
+  #define subjectHomePresence "/homePresence/salon" // will send Home Assistant room presence message to this topic (first part is same for all rooms, second is room name)
+#endif
+
+
 struct decompose
 {
   char subject[4];