diff --git a/include/MQTTHelper.h b/include/MQTTHelper.h
index 29350d5..15eac6c 100644
--- a/include/MQTTHelper.h
+++ b/include/MQTTHelper.h
@@ -13,6 +13,8 @@ class MQTTHelper {
     WiFiClient _espClient;
     PubSubClient _mqttClient;
     String  _will_topic;
+    String _command_topic;
+    String _announce_topic;
     
     void reconnect(int delayMillis = 5000);
     bool connect();
@@ -24,6 +26,8 @@ class MQTTHelper {
         deviceMac.replace(":","");
         _identifier = "etxean-"+deviceMac.substring(6);
         _will_topic = getTopic("online");
+        _command_topic = _group + "/command";
+        _announce_topic = _group+"/announce";
         _mqttClient.setCallback([this] (char* topic, byte* payload, unsigned int length) { this->callback(topic, payload, length); });
     }
 
@@ -34,7 +38,7 @@ class MQTTHelper {
     }
     
     void Configure(IPAddress server, uint16 port) {
-        Serial.println("Configuring MQTT connection to: "+server.toString()+":"+String(port));
+        Serial.println("MQTT: configuring connection to "+server.toString()+":"+String(port));
         _mqttClient.setServer(server, port);
         if (_mqttClient.connected()) {
             connect();
@@ -42,40 +46,48 @@ class MQTTHelper {
     }
     
     void loop() {
-        static unsigned long lastWill;
+        static unsigned long lastWillTopicSent;
         if (!_mqttClient.connected()) {
             reconnect();
         }
         _mqttClient.loop();
 
         auto now = millis();
-        if ((now - lastWill) > 1000)
+        if ((now - lastWillTopicSent) > 1000)
         {
-            lastWill = now;
+            lastWillTopicSent = now;
             _mqttClient.publish(_will_topic.c_str(), "true");
         }
     }
 
     template<class T>
-    void publish(String sensor, T payload, bool retained = false) {
-        _mqttClient.publish(getTopic(sensor).c_str(), String(payload).c_str(), retained);
+    void publish(String node, T payload, bool retained = false, bool debug = true) {
+        auto topic = getTopic(node);
+        auto payload_s = String(payload);
+        if (debug)
+            Serial.println("MQTT: publish: "+topic+" = "+payload_s);
+        _mqttClient.publish(topic.c_str(), payload_s.c_str(), retained);
     }
 };
 
-void MQTTHelper::callback(char* topic, byte* payload, unsigned int length) {
-    Serial.print("Message arrived:");
-    Serial.print(topic);
-    Serial.print(" = ");
-    for (unsigned int i=0;  i<length; i++) {
-        Serial.print((char)payload[i]);
+void MQTTHelper::callback(char* topic_chars, byte* payload_bytes, unsigned int length) {
+    String topic(topic_chars);
+    payload_bytes[length] = '\0';
+    String payload = (char*)payload_bytes;
+    Serial.print("MQTT: callback on: ");
+    Serial.println(topic+" = "+payload);
+    String commandTopic = getTopic("command");
+    
+    if (topic == _command_topic && payload == "announce") {
+        Serial.println("Announcing");
+        announce();
     }
-    Serial.println();
 }
 
 void MQTTHelper::reconnect(int delayMillis) {
   // Loop until we're reconnected
   while (!_mqttClient.connected()) {
-    Serial.print("Attempting MQTT connection...");
+    Serial.print("MQTT: attempting connection...");
     if (connect()) {
         Serial.println("connected");
     } else {
@@ -91,19 +103,26 @@ void MQTTHelper::reconnect(int delayMillis) {
 
 void MQTTHelper::announce() {
     DynamicJsonDocument doc(1024);
-    doc["id"] = _identifier;
     doc["ip"] = WiFi.localIP().toString();
     doc["mac"] = WiFi.macAddress();
-    String payload;
-    serializeJson(doc,payload);
-    publish("settings",payload);
+    String payloadSettings;
+    serializeJson(doc,payloadSettings);
+    // publish to settings topic
+    publish("settings", payloadSettings);
+    
+    doc["id"] = _identifier;
+    String payloadAnnounce;
+    serializeJson(doc,payloadAnnounce);
+    // publish to genneral announce topic
+    Serial.println("MQTT: "+_announce_topic+" = "+payloadAnnounce);
+    _mqttClient.publish(_announce_topic.c_str(),payloadAnnounce.c_str());
 }
 
 bool MQTTHelper::connect() {
     // If you do not want to use a username and password, change next line to
     // if (_mqttClient.connect(_identifier.c_str()) {    
     if (_mqttClient.connect(_identifier.c_str(), _user, _password, _will_topic.c_str(), 2, false, "false")) {
-        _mqttClient.subscribe((getTopic("settings")+"/get").c_str());
+        _mqttClient.subscribe((_command_topic).c_str());
         announce();
         return true;
     } else {
diff --git a/src/main.cpp b/src/main.cpp
index af38e0f..fba697e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -114,14 +114,10 @@ void loop() {
     // Serial.println(" mm");
 
     if (checkBounds(distance, 0, maxDistance)) {
-      String node = "distance";
-      Serial.println(mqtt.getTopic(node)+" = "+String(distance));
-      mqtt.publish(node, distance);
+      mqtt.publish("distance", distance);
 
       bool signal = signalChange(distance, oldDistance);
-      node = "signal";
-      Serial.println(mqtt.getTopic(node)+" = "+String(signal));
-      mqtt.publish(node, signal);
+      mqtt.publish("signal", signal);
       if (signal)
         signal_led();
     }
@@ -166,13 +162,11 @@ void readConfig() {
         DynamicJsonDocument doc(1024);
         DeserializationError error = deserializeJson(doc,configFile);
         serializeJsonPretty(doc,Serial);
-        Serial.println();
         if (error) {
           Serial.print("failed to load config.json: ");
           Serial.println(error.c_str());
           return;
         }
-  
         Serial.println("\nparsed config.json");
         IPAddress addr;
         if (addr.fromString(doc["mqtt_server"].as<char*>())) {