diff --git a/README.md b/README.md
index eabd584..623f5ca 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,15 @@
-# arduino-home-assistant
\ No newline at end of file
+# Arduino Home Assistant
+
+## Examples
+
+## Compatible boards
+
+## Compatible Arduino Shields
+
+## Roadmap
+
+- [ ] Add support for "Lights" device's type
+- [ ] Add support for "Sensor" device's type
+- [ ] Add support for "Tag scanner" device's type
+- [ ] Add support for "Lock" device's type
+- [ ] Add support for "Binary sensor" device's type
diff --git a/src/HAMqtt.cpp b/src/HAMqtt.cpp
index 30e213d..da4fcd4 100644
--- a/src/HAMqtt.cpp
+++ b/src/HAMqtt.cpp
@@ -20,6 +20,11 @@
 
 const char* HAMqtt::DefaultDiscoveryPrefix = "homeassistant";
 
+void onMessageReceived(char* topic, char* message, uint32_t length)
+{
+    // todo: process message
+}
+
 HAMqtt::HAMqtt(const char* clientId, Client& netClient) :
     _clientId(clientId),
     _netClient(netClient),
@@ -70,7 +75,7 @@ bool HAMqtt::begin(
     _initialized = true;
 
     _mqtt->setServer(*_serverIp, _serverPort);
-    // _mqtt->setCallback(...);
+    _mqtt->setCallback(onMessageReceived);
 
     return true;
 }
@@ -160,6 +165,17 @@ bool HAMqtt::endPublish()
     return _mqtt->endPublish();
 }
 
+bool HAMqtt::subscribe(const char* topic)
+{
+    #if defined(ARDUINOHA_DEBUG)
+        Serial.print(F("Subscribing topic: "));
+        Serial.print(topic);
+        Serial.println();
+    #endif
+
+    return _mqtt->subscribe(topic);
+}
+
 void HAMqtt::connectToServer()
 {
     if (_lastConnectionAttemptAt > 0 &&
diff --git a/src/HAMqtt.h b/src/HAMqtt.h
index 0a3d437..15eefc5 100644
--- a/src/HAMqtt.h
+++ b/src/HAMqtt.h
@@ -94,6 +94,7 @@ public:
     bool writePayload(const char* data, uint16_t length);
     bool writePayload_P(const char* src);
     bool endPublish();
+    bool subscribe(const char* topic);
 
 private:
     /**
diff --git a/src/device-types/HASwitch.cpp b/src/device-types/HASwitch.cpp
index 904e245..20db3da 100644
--- a/src/device-types/HASwitch.cpp
+++ b/src/device-types/HASwitch.cpp
@@ -28,7 +28,12 @@ HASwitch::~HASwitch()
 
 void HASwitch::onMqttConnected()
 {
+    if (strlen(_name) == 0) {
+        return;
+    }
+
     publishConfig();
+    subscribeCommandTopic();
 }
 
 void HASwitch::setState(bool state)
@@ -74,10 +79,6 @@ void HASwitch::triggerCallback(bool state)
 
 void HASwitch::publishConfig()
 {
-    if (strlen(_name) == 0) {
-        return;
-    }
-
     const HADevice* device = mqtt()->getDevice();
     uint16_t deviceLength = (device == nullptr ? 0 : device->calculateSerializedLength());
     char serializedDevice[deviceLength];
@@ -120,6 +121,24 @@ void HASwitch::publishCurrentState()
     mqtt()->publish(topic, (_currentState ? StateOn : StateOff));
 }
 
+void HASwitch::subscribeCommandTopic()
+{
+    const uint16_t& topicSize = calculateTopicLength(
+        HAComponentName,
+        _name,
+        CommandTopic
+    );
+    char topic[topicSize];
+    generateTopic(
+        topic,
+        HAComponentName,
+        _name,
+        CommandTopic
+    );
+
+    mqtt()->subscribe(topic);
+}
+
 uint16_t HASwitch::calculateSerializedLength(const char* serializedDevice) const
 {
     const uint16_t& cmdTopicLength = calculateTopicLength(
diff --git a/src/device-types/HASwitch.h b/src/device-types/HASwitch.h
index 757f85d..0237536 100644
--- a/src/device-types/HASwitch.h
+++ b/src/device-types/HASwitch.h
@@ -23,6 +23,7 @@ private:
     void triggerCallback(bool state);
     void publishConfig();
     void publishCurrentState();
+    void subscribeCommandTopic();
     uint16_t calculateSerializedLength(const char* serializedDevice) const;
     bool writeSerializedTrigger(const char* serializedDevice) const;