diff --git a/app/src/main/java/ch/luria/mq1/MainActivity.java b/app/src/main/java/ch/luria/mq1/MainActivity.java
index a3bf4d3..cda6db4 100644
--- a/app/src/main/java/ch/luria/mq1/MainActivity.java
+++ b/app/src/main/java/ch/luria/mq1/MainActivity.java
@@ -61,11 +61,7 @@ public class MainActivity extends AppCompatActivity {
     }
 
     public void toggleButtonState(View view) {
-        if (stateButton.isChecked()) {
-            mService.doToggle("{\"state\":\"ON\"}");
-        } else {
-            mService.doToggle("{\"state\":\"OFF\"}");
-        }
+        mService.doToggle(stateButton.isChecked());
     }
 
     private final ServiceConnection connection = new ServiceConnection() {
diff --git a/app/src/main/java/ch/luria/mq1/MqttService.java b/app/src/main/java/ch/luria/mq1/MqttService.java
index 10f7a2a..2299044 100644
--- a/app/src/main/java/ch/luria/mq1/MqttService.java
+++ b/app/src/main/java/ch/luria/mq1/MqttService.java
@@ -6,6 +6,7 @@ import android.os.Binder;
 import android.os.IBinder;
 import android.util.Log;
 
+import com.hivemq.client.mqtt.MqttClientState;
 import com.hivemq.client.mqtt.mqtt5.Mqtt5AsyncClient;
 import com.hivemq.client.mqtt.mqtt5.Mqtt5Client;
 
@@ -36,46 +37,38 @@ public class MqttService extends Service {
                     .serverHost("192.168.178.64")
                     .serverPort(1883)
                     .buildAsync();
-            client.connectWith()
-                    .send()
-                    .whenComplete((connAck, throwable) -> {
-                        if (throwable != null) {
-                            // handle failure
-                            Log.i(TAG, "could not connect");
-                        } else {
-                            Log.i(TAG, "connect ok");
-                            subscribe();
-                        }
-                    });
         }
     }
 
     @Override
     public IBinder onBind(Intent intent) {
         Log.i(TAG, "onBind");
+        connect();
         return binder;
     }
 
-    public void doToggle(String what) {
-        publishMessage("zigbee2mqtt/Ampoule Chambre Isaac/set", what);
-    }
-
-    private void sendMessage(String msg) {
-        Intent intent = new Intent();
-        intent.setAction("ch.luria.mq1");
-        try {
-            final JSONObject obj = new JSONObject(msg);
-            String state = obj.getString("state");
-            intent.putExtra("STATE", state);
-            sendBroadcast(intent);
-        } catch (JSONException e) {
-            e.printStackTrace();
+    private void connect() {
+        if (client.getState() == MqttClientState.DISCONNECTED) {
+            Log.i(TAG, "connect()");
+            client.connectWith()
+                    .send()
+                    .whenComplete((connAck, throwable) -> {
+                        if (throwable != null) {
+                            // handle failure
+                            Log.i(TAG, "could not connect - " + connAck.getReasonString());
+                        } else {
+                            Log.i(TAG, "connect ok");
+                            subscribe();
+                        }
+                    });
+        } else {
+            Log.i(TAG, "connect() in state " + client.getState());
         }
     }
 
     private void subscribe() {
         client.subscribeWith()
-                .topicFilter("zigbee2mqtt/Ampoule Chambre Isaac")
+                .topicFilter(getString(R.string.mqtt_base_topic) + "/" + getString(R.string.mqtt_room_address))
                 .callback(publish -> {
                     // Process the received message
                     String msg = new String(publish.getPayloadAsBytes()) + " from " + publish.getTopic();
@@ -93,42 +86,65 @@ public class MqttService extends Service {
                         getStatus();
                     }
                 });
-
     }
 
-    public void getStatus() {
-        if (client != null) {
-            client.publishWith()
-                    .topic("zigbee2mqtt/Ampoule Chambre Isaac/get")
-                    .payload("{\"state\":\"\"}".getBytes())
-                    .send()
-                    .whenComplete((mqtt3Publish, throwable) -> {
-                        if (throwable != null) {
-                            // handle failure to publish
-                            Log.i(TAG, "could not publish");
-                        } else {
-                            // handle successful publish, e.g. logging or incrementing a metric
-                            Log.i(TAG, "published");
-                        }
-                    });
+    private void sendMessage(String msg) {
+        Intent intent = new Intent();
+        intent.setAction("ch.luria.mq1");
+        try {
+            final JSONObject obj = new JSONObject(msg);
+            String state = obj.getString("state");
+            intent.putExtra("STATE", state);
+            sendBroadcast(intent);
+        } catch (JSONException e) {
+            e.printStackTrace();
         }
     }
 
     private void publishMessage(String topic, String message) {
-        client.publishWith()
-                .topic(topic)
-                .payload(message.getBytes())
-                .send()
-                .whenComplete((mqtt3Publish, throwable) -> {
-                    if (throwable != null) {
-                        // handle failure to publish
-                        Log.i(TAG, "could not publish");
-                    } else {
-                        // handle successful publish, e.g. logging or incrementing a metric
-                        Log.i(TAG, "published " + message + " on " + topic);
-                        getStatus();
-                    }
-                });
+        if (client != null) {
+            if (client.getState() == MqttClientState.CONNECTED) {
+                client.publishWith()
+                        .topic(topic)
+                        .payload(message.getBytes())
+                        .send()
+                        .whenComplete((mqttPublish, throwable) -> {
+                            if (throwable != null) {
+                                // handle failure to publish
+                                Log.i(TAG, "publishMessage(): could not publish: " + throwable);
+                            } else {
+                                // handle successful publish, e.g. logging or incrementing a metric
+                                Log.i(TAG, "published " + message + " on " + topic);
+                                getStatus();
+                            }
+                        });
+            } else {
+                Log.i(TAG, "publishMessage(): not connected");
+            }
+        } else {
+            Log.i(TAG, "publishMessage(): null client");
+        }
     }
 
+    public void doToggle(boolean state) {
+        JSONObject obj = new JSONObject();
+        try {
+            obj.put("state", state ? "ON" : "OFF");
+            Log.i(TAG, "doToggle: " + obj);
+            publishMessage(getString(R.string.mqtt_base_topic) + "/" + getString(R.string.mqtt_room_address) + "/set", obj.toString());
+        } catch (JSONException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void getStatus() {
+        JSONObject obj = new JSONObject();
+        try {
+            obj.put("state", "");
+            Log.i(TAG, "getStatus()");
+            publishMessage(getString(R.string.mqtt_base_topic) + "/" + getString(R.string.mqtt_room_address) + "/get", obj.toString());
+        } catch (JSONException e) {
+            e.printStackTrace();
+        }
+    }
 }
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 2cd4de7..3e03361 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -3,4 +3,6 @@
     <string name="button_on">ALLUMEE</string>
     <string name="button_off">ETEINTE</string>
     <string name="room_name">Chambre d\'Isaac</string>
+    <string name="mqtt_base_topic">zigbee2mqtt</string>
+    <string name="mqtt_room_address">Ampoule Chambre Isaac</string>
 </resources>
\ No newline at end of file