Release 1.3.0 (#36 )

* Add support for HVAC (#15) * remove HASwitch::triggerCallback method * fix typo in docs * HASwitch: simplify callback #define * work in progress: HVAC * replace local mqtt instances with singleton * device types optimization * cleanup * finished aux heating and away mode * wip: HVAC * finished HVAC implementation * HVAC implementation * add ifdefs for all HA components * wip: optimization * update readme * update examples * remove unused constructor from HAMqtt * update HAUtils * remove mqtt from constructors, fix compilation warnings * finished HVAC * add HVAC example, add changelog * update changelog, add documentation * Add support for icons in HASwitch and HASensor (#16) * add support for icon in HASwitch * add support for icon in HASensor * update changelog * add support for setting retain flag in HASwitch * Add support for text payload in HASensor (#17) * refactored HASensor * update changelog * fix sensor example * Add support for fans (HAFan) (#18) * finished basic implementation of the HAFan * add retain method to DeviceTypeSerializer * finished HAFan implementation * update HAHVAC * device types cleanup * add HAFan example * update changelog * update readme * update fan example * optimization, add support for ActionFeature in HVAC * Add support for MQTT LWT (#19) * add support for hostname in HAMqtt * add support for LWT and shared availability * minor fixes * added advanced availability example * update examples * update changelog * cleanup & bug fix * bump up version * minor improvements and fixes * update readme * add HAMqtt::onMessage method * Add support for covers (#28) * add HACovers * add cover example, update implementation * disable debug * update mqtt-events example * Add support for setting different prefix for non-discovery topics (#29) * add support for data prefix * cleanup * update comments and logs * update multi-state-button example * rename rexample from mqtt-events to mqtt-advanced * update changelog * update links in changelog * Home Assistant 2021.4.5 - MQTT upgrade (#33) * updae HAFan implementation * change lib version * update changelog * fix setSpeed method * update HAFan example * Separate uniqueId from name (#34) * rename name to uniqueId * remove legacy labels * update examples * rename isMyTopic to compareTopics * update changelog, rename name to uniqueId * Implement onBeforeStateChanged callback in HASwitch (#35) * add low latency mode to HASwitch * add onBeforeStateChanged callback to HASwitch * update readme * rename DEPRECATED macro * update advanced MQTT example
Release 1.2.0 (#21 )
2026-10-04 02:48:13 +10:00 · 2021-04-17 20:03:32 +02:00 · 2021-03-23 13:23:56 +01:00
45 changed files with 3989 additions and 1054 deletions
@@ -0,0 +1,37 @@
+# Changelog
+
+## 1.3.0
+
+**New features:**
+* Added `onMessage()` method to HAMqtt class
+* Added support for HA Covers
+* Added support for setting different prefix for non-discovery topics (see [Advanced MQTT example](examples/mqtt-advanced/mqtt-advanced.ino))
+* Added `setName` method to HASensor
+* Added `setName` method to HASwitch
+* Added `onBeforeStateChanged` callback to HASwitch
+
+**Updates:**
+* Removed legacy properties from HAFan (Home Assistant 2021.4.4). Deprecated methods will be removed after a quarter (2021.7)
+* Separated `uniqueID` field from `name` in all devices types
+
+## 1.2.0
+
+**Breaking changes:**
+* Refactored HASensor implementation. Please take a look at [updated example](examples/sensor/sensor.ino)
+
+**New features:**
+* Added support for HVAC
+* Added support for excluding devices types from the compilation using defines (see [src/ArduinoHADefines.h](src/ArduinoHADefines.h))
+* Added support for setting icon in HASwitch and HASensor
+* Added support for setting retain flag in HASwitch
+* Added support for text (const char*) payload in HASensor
+* Added support for fans (HAFan)
+* Added support for connecting to the MQTT broker using hostname
+* Added `onConnected()` method in the HAMqtt
+* Added `onConnectionFailed()` method in the HAMqtt
+* Added support for MQTT LWT (see [Advanced Availability example](examples/advanced-availability/advanced-availability.ino))
+
+**Updates:**
+* Optimized codebase and logic in all devices types
+* Updated all examples
+* Fixed compilation warnings in all classes
@@ -8,41 +8,68 @@ but I successfully use it on ESP8266/ESP8255 boards in my projects.
 ## Features

 * MQTT discovery (device is added to the Home Assistant panel automatically)
+* MQTT Last Will and Testament
+* Support for custom MQTT messages (publishing and subscribing)
 * Auto reconnect with MQTT broker
+* Reporting availability (online/offline states) of a device
+
+## Supported HA types
+
+* Binary sensors
+* Covers
+* Fans
+* Device triggers
+* Switches
+* Sensors
+* Tag scanner
+* HVACs *(side note: HVACs requires more flash size than other HA types. It's not suitable for Arduino Nano/Uno)*

 ## Examples

 * [Binary Sensor](examples/binary-sensor/binary-sensor.ino)
+* [Cover](examples/cover/cover.ino)
+* [Fan](examples/fan/fan.ino)
 * [LED switch](examples/led-switch/led-switch.ino)
-* [MQTT with credentials](examples/mqtt-with-credentials/mqtt-with-credentials.ino)
 * [Multi-state button](examples/multi-state-button/multi-state-button.ino)
 * [Sensor (temperature, humidity, etc.)](examples/sensor/sensor.ino)
+* [HVAC](examples/hvac/hvac.ino)
 * [NodeMCU Wi-Fi](examples/nodemcu/nodemcu.ino)
 * [Arduino Nano 33 IoT Wi-Fi (SAMD)](examples/nano33iot/nano33iot.ino)
 * [Availability feature](examples/availability)
+* [Advanced availability (MQTT LWT)](examples/advanced-availability/advanced-availability.ino)
+* [MQTT with credentials](examples/mqtt-with-credentials/mqtt-with-credentials.ino)
+* [MQTT advanced](examples/mqtt-advanced/mqtt-advanced.ino)

 ## Tested boards

 * Arduino Uno
 * Arduino Mega
-* Controllino Maxi (standard/pure/automation/power)
-* Controllino Mega (standard/pure)
 * NodeMCU
 * ESP-01
 * Generic ESP8266/ESP8255
 * Arduino Nano 33 IoT (SAMD)

+## Tested devices
+
+* Controllino Maxi (standard/pure/automation/power)
+* Controllino Mega (standard/pure)
+* Sonoff Dual R2
+* Sonoff Basic
+* Sonoff Mini
+* Tuya Wi-Fi switch module
+* Tuya Wi-Fi curtain module
+
 ## Tested Arduino Shields

 * Arduino Ethernet Shield (WizNet W5100)

-## Supported HA types
+## Roadmap

-* Binary sensors
-* Device triggers
-* Switches
-* Sensors
-* Tag scanner
+* FAQ + Home Assistant setup instructions
+* Documentation of the library
+* Unit tests
+* Reduce flash memory usage
+* Add support for HA lights

 ## Unsupported features

@@ -0,0 +1,66 @@
+#include <Ethernet.h>
+#include <ArduinoHA.h>
+
+#define INPUT_PIN       9
+#define BROKER_ADDR     IPAddress(192,168,0,17)
+
+byte mac[] = {0x00, 0x10, 0xFA, 0x6E, 0x38, 0x4A};
+unsigned long lastReadAt = millis();
+unsigned long lastAvailabilityToggleAt = millis();
+bool lastInputState = false;
+
+EthernetClient client;
+HADevice device(mac, sizeof(mac));
+HAMqtt mqtt(client, device);
+
+// "input" is unique ID of the sensor. You should define you own ID.
+// "door" is device class (based on the class HA displays different icons in the panel)
+// "true" is initial state of the sensor. In this example it's "true" as we use pullup resistor
+HABinarySensor sensor("input", "door", true);
+
+void setup() {
+    pinMode(INPUT_PIN, INPUT_PULLUP);
+    lastInputState = digitalRead(INPUT_PIN);
+
+    // you don't need to verify return status
+    Ethernet.begin(mac);
+
+    lastReadAt = millis();
+    lastAvailabilityToggleAt = millis();
+
+    // set device's details (optional)
+    device.setName("Arduino");
+    device.setSoftwareVersion("1.0.0");
+
+    sensor.setName("Door sensor"); // optional
+
+    // This method enables availability for all device types registered on the device.
+    // For example, if you have 5 sensors on the same device, you can enable
+    // shared availability and change availability state of all sensors using
+    // single method call "device.setAvailability(false|true)"
+    device.enableSharedAvailability();
+
+    // Optionally, you can enable MQTT LWT feature. If device will lose connection
+    // to the broker, all device types related to it will be marked as offline in
+    // the Home Assistant Panel.
+    device.enableLastWill();
+
+    mqtt.begin(BROKER_ADDR);
+}
+
+void loop() {
+    Ethernet.maintain();
+    mqtt.loop();
+
+    if ((millis() - lastReadAt) > 30) { // read in 30ms interval
+        // library produces MQTT message if a new state is different than the previous one
+        sensor.setState(digitalRead(INPUT_PIN));
+        lastInputState = sensor.getState();
+        lastReadAt = millis();
+    }
+
+    if ((millis() - lastAvailabilityToggleAt) > 5000) {
+        device.setAvailability(!device.isOnline());
+        lastAvailabilityToggleAt = millis();
+    }
+}
@@ -5,6 +5,8 @@ It's supported only by following device types:
 * Binary sensor
 * Sensor
 * Switch
+* HVACs
+* Fans

 ## Initialization and usage

@@ -13,10 +13,10 @@ EthernetClient client;
 HADevice device(mac, sizeof(mac));
 HAMqtt mqtt(client, device);

-// "input" may be anything you want to be displayed in HA panel
+// "input" is unique ID of the sensor. You should define you own ID.
 // "door" is device class (based on the class HA displays different icons in the panel)
 // "true" is initial state of the sensor. In this example it's "true" as we use pullup resistor
-HABinarySensor sensor("input", "door", true, mqtt);
+HABinarySensor sensor("input", "door", true);

 void setup() {
    pinMode(INPUT_PIN, INPUT_PULLUP);
@@ -26,6 +26,7 @@ void setup() {
    Ethernet.begin(mac);

    // turn on "availability" feature
+    // this method also sets initial availability so you can use "true" or "false"
    sensor.setAvailability(false);

    lastReadAt = millis();
@@ -35,6 +36,8 @@ void setup() {
    device.setName("Arduino");
    device.setSoftwareVersion("1.0.0");

+    sensor.setName("Door sensor"); // optional
+
    mqtt.begin(BROKER_ADDR);
 }

@@ -12,10 +12,10 @@ EthernetClient client;
 HADevice device(mac, sizeof(mac));
 HAMqtt mqtt(client, device);

-// "input" may be anything you want to be displayed in HA panel
+// "input" is unique ID of the sensor. You should define you own ID.
 // "door" is device class (based on the class HA displays different icons in the panel)
 // "true" is initial state of the sensor. In this example it's "true" as we use pullup resistor
-HABinarySensor sensor("input", "door", true, mqtt);
+HABinarySensor sensor("input", "door", true);

 void setup() {
    pinMode(INPUT_PIN, INPUT_PULLUP);
@@ -28,6 +28,8 @@ void setup() {
    device.setName("Arduino");
    device.setSoftwareVersion("1.0.0");

+    sensor.setName("Door sensor"); // optional
+
    mqtt.begin(BROKER_ADDR);
 }

@@ -0,0 +1,49 @@
+#include <Ethernet.h>
+#include <ArduinoHA.h>
+
+#define BROKER_ADDR     IPAddress(192,168,0,17)
+
+byte mac[] = {0x00, 0x10, 0xFA, 0x6E, 0x38, 0x4A};
+
+EthernetClient client;
+HADevice device(mac, sizeof(mac));
+HAMqtt mqtt(client, device);
+HACover cover("my-cover"); // "my-cover" is unique ID of the cover. You should define your own ID.
+
+void onCoverCommand(HACover::CoverCommand cmd) {
+    if (cmd == HACover::CommandOpen) {
+        Serial.println("Command: Open");
+        cover.setState(HACover::StateOpening);
+    } else if (cmd == HACover::CommandClose) {
+        Serial.println("Command: Close");
+        cover.setState(HACover::StateClosing);
+    } else if (cmd == HACover::CommandStop) {
+        Serial.println("Command: Stop");
+        cover.setState(HACover::StateStopped);
+    }
+
+    // Available states:
+    // HACover::StateClosed
+    // HACover::StateClosing
+    // HACover::StateOpen
+    // HACover::StateOpening
+    // HACover::StateStopped
+
+    // You can also report position using setPosition() method
+}
+
+void setup() {
+    Serial.begin(9600);
+    Ethernet.begin(mac);
+
+    cover.onCommand(onCoverCommand);
+    cover.setName("My cover"); // optional
+    // cover.setRetain(true); // optionally you can set retain flag
+
+    mqtt.begin(BROKER_ADDR);
+}
+
+void loop() {
+    Ethernet.maintain();
+    mqtt.loop();
+}
@@ -0,0 +1,53 @@
+#include <Ethernet.h>
+#include <ArduinoHA.h>
+
+#define BROKER_ADDR     IPAddress(192,168,0,17)
+
+byte mac[] = {0x00, 0x10, 0xFA, 0x6E, 0x38, 0x4A};
+
+EthernetClient client;
+HADevice device(mac, sizeof(mac));
+HAMqtt mqtt(client, device);
+
+// HAFan::SpeedsFeature enables support for setting different speeds of fan.
+// You can skip this argument if you don't need speed management.
+// "ventilation" is unique ID of the fan. You should define your own ID.
+HAFan fan("ventilation", HAFan::SpeedsFeature);
+
+void onStateChanged(bool state) {
+    Serial.print("State: ");
+    Serial.println(state);
+}
+
+void onSpeedChanged(uint16_t speed) {
+    Serial.print("Speed: ");
+    Serial.println(speed);
+}
+
+void setup() {
+    Serial.begin(9600);
+
+    // you don't need to verify return status
+    Ethernet.begin(mac);
+
+    // set device's details (optional)
+    device.setName("Arduino");
+    device.setSoftwareVersion("1.0.0");
+
+    // configure fan (optional)
+    fan.setName("Bathroom");
+    fan.setRetain(true);
+    fan.setSpeedRangeMin(1);
+    fan.setSpeedRangeMax(100);
+
+    // handle fan states
+    fan.onStateChanged(onStateChanged);
+    fan.onSpeedChanged(onSpeedChanged);
+
+    mqtt.begin(BROKER_ADDR);
+}
+
+void loop() {
+    Ethernet.maintain();
+    mqtt.loop();
+}
@@ -0,0 +1,102 @@
+#include <ESP8266WiFi.h>
+#include <ArduinoHA.h>
+
+#define BROKER_ADDR     IPAddress(192,168,0,17)
+#define WIFI_SSID       "MyNetwork"
+#define WIFI_PASSWORD   "MyPassword"
+
+WiFiClient client;
+HADevice device;
+HAMqtt mqtt(client, device);
+
+// see src/device-types/HAHVAC.h header for more details
+HAHVAC hvac("my_name", HAHVAC::AuxHeatingFeature | HAHVAC::AwayModeFeature | HAHVAC::HoldFeature);
+
+unsigned long lastTempPublishAt = 0;
+double lastTemp = 0;
+
+void onAuxHeatingStateChanged(bool state) {
+    Serial.print("Aux heating: ");
+    Serial.println(state);
+}
+
+void onAwayStateChanged(bool state) {
+    Serial.print("Away state: ");
+    Serial.println(state);
+}
+
+void onHoldStateChanged(bool state) {
+    Serial.print("Hold state: ");
+    Serial.println(state);
+}
+
+void onTargetTemperatureChanged(double temp) {
+    Serial.print("Target temperature: ");
+    Serial.println(temp);
+}
+
+void onModeChanged(HAHVAC::Mode mode) {
+    Serial.print("Mode: ");
+    if (mode == HAHVAC::OffMode) {
+        Serial.println("off");
+    } else if (mode == HAHVAC::AutoMode) {
+        Serial.println("auto");
+    } else if (mode == HAHVAC::CoolMode) {
+        Serial.println("cool");
+    } else if (mode == HAHVAC::HeatMode) {
+        Serial.println("heat");
+    } else if (mode == HAHVAC::DryMode) {
+        Serial.println("dry");
+    } else if (mode == HAHVAC::FanOnlyMode) {
+        Serial.println("fan only");
+    }
+}
+
+void setup() {
+    Serial.begin(9600);
+    Serial.println("Starting...");
+
+    // Unique ID must be set!
+    byte mac[WL_MAC_ADDR_LENGTH];
+    WiFi.macAddress(mac);
+    device.setUniqueId(mac, sizeof(mac));
+
+    // connect to wifi
+    WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
+    while (WiFi.status() != WL_CONNECTED) {
+        Serial.print(".");
+        delay(500); // waiting for the connection
+    }
+    Serial.println();
+    Serial.println("Connected to the network");
+
+    // set device's details (optional)
+    device.setName("NodeMCU");
+    device.setSoftwareVersion("1.0.0");
+
+    // assign callbacks (optional)
+    hvac.onAuxHeatingStateChanged(onAuxHeatingStateChanged);
+    hvac.onAwayStateChanged(onAwayStateChanged);
+    hvac.onHoldStateChanged(onHoldStateChanged);
+    hvac.onTargetTemperatureChanged(onTargetTemperatureChanged);
+    hvac.onModeChanged(onModeChanged);
+
+    // configure HVAC (optional)
+    hvac.setName("My HVAC");
+    hvac.setMinTemp(10);
+    hvac.setMaxTemp(30);
+    hvac.setTempStep(0.5);
+    hvac.setRetain(true);
+
+    mqtt.begin(BROKER_ADDR);
+}
+
+void loop() {
+    mqtt.loop();
+
+    if ((millis() - lastTempPublishAt) > 3000) {
+        hvac.setCurrentTemperature(lastTemp);
+        lastTempPublishAt = millis();
+        lastTemp += 0.5;
+    }
+}
@@ -9,7 +9,13 @@ byte mac[] = {0x00, 0x10, 0xFA, 0x6E, 0x38, 0x4A};
 EthernetClient client;
 HADevice device(mac, sizeof(mac));
 HAMqtt mqtt(client, device);
-HASwitch led("led", false, mqtt); // you can use custom name in place of "led"
+HASwitch led("led", false); // "led" is unique ID of the switch. You should define your own ID.
+
+void onBeforeSwitchStateChanged(bool state, HASwitch* s)
+{
+    // this callback will be called before publishing new state to HA
+    // in some cases there may be delay before onStateChanged is called due to network latency
+}

 void onSwitchStateChanged(bool state, HASwitch* s)
 {
@@ -27,7 +33,12 @@ void setup() {
    device.setName("Arduino");
    device.setSoftwareVersion("1.0.0");

+    // set icon (optional)
+    led.setIcon("mdi:lightbulb");
+    led.setName("My LED");
+
    // handle switch state
+    led.onBeforeStateChanged(onBeforeSwitchStateChanged); // optional
    led.onStateChanged(onSwitchStateChanged);

    mqtt.begin(BROKER_ADDR);
@@ -0,0 +1,56 @@
+#include <Ethernet.h>
+#include <ArduinoHA.h>
+
+#define BROKER_ADDR         IPAddress(192,168,0,17)
+
+byte mac[] = {0x00, 0x10, 0xFA, 0x6E, 0x38, 0x4A};
+
+EthernetClient client;
+HADevice device(mac, sizeof(mac));
+HAMqtt mqtt(client, device);
+
+void onMqttMessage(const char* topic, const uint8_t* payload, uint16_t length) {
+    // This callback is called when message from MQTT broker is received.
+    // Please note that you should always verify if the message's topic is the one you expect.
+    // For example: if (memcmp(topic, "myCustomTopic") == 0) { ... }
+
+    Serial.print("New message on topic: ");
+    Serial.println(topic);
+    Serial.print("Data: ");
+    Serial.println((const char*)payload);
+
+    mqtt.publish("myPublishTopic", "hello");
+}
+
+void onMqttConnected() {
+    Serial.println("Connected to the broker!");
+
+    // You can subscribe to custom topic if you need
+    mqtt.subscribe("myCustomTopic");
+}
+
+void onMqttConnectionFailed() {
+    Serial.println("Failed to connect to the broker!");
+}
+
+void setup() {
+    Serial.begin(9600);
+    Ethernet.begin(mac);
+
+    mqtt.onMessage(onMqttMessage);
+    mqtt.onConnected(onMqttConnected);
+    mqtt.onConnectionFailed(onMqttConnectionFailed);
+
+    // If you use custom discovery prefix you can change it as following:
+    // mqtt.setDiscoveryPrefix("customPrefix");
+
+    // If you want to change prefix only for non-discovery prefix:
+    // mqtt.setDataPrefix("data");
+
+    mqtt.begin(BROKER_ADDR);
+}
+
+void loop() {
+    Ethernet.maintain();
+    mqtt.loop();
+}
@@ -11,7 +11,7 @@ byte mac[] = {0x00, 0x10, 0xFA, 0x6E, 0x38, 0x4A};
 EthernetClient client;
 HADevice device(mac, sizeof(mac));
 HAMqtt mqtt(client, device);
-HASwitch led("led", false, mqtt); // you can use custom name in place of "led"
+HASwitch led("led", false); // "led" is unique ID of the switch. You should define your own ID.

 void onSwitchStateChanged(bool state, HASwitch* s)
 {
@@ -31,6 +31,7 @@ void setup() {

    // handle switch state
    led.onStateChanged(onSwitchStateChanged);
+    led.setName("My LED"); // optional

    mqtt.begin(BROKER_ADDR, BROKER_USERNAME, BROKER_PASSWORD);
 }
@@ -14,7 +14,7 @@ byte mac[] = {0x00, 0x10, 0xFA, 0x6E, 0x38, 0x4A};
 EthernetClient client;
 HADevice device(mac, sizeof(mac));
 HAMqtt mqtt(client, device);
-HATriggers triggers(mqtt);
+HATriggers triggers;
 Button btn(BUTTON_PIN);
 bool holdingBtn = false;

@@ -22,8 +22,6 @@ void setup() {
    // you don't need to verify return status
    Ethernet.begin(mac);

-    Serial.println(Ethernet.localIP());
-
    // set device's details (optional)
    device.setName("Arduino");
    device.setSoftwareVersion("1.0.0");
@@ -9,7 +9,7 @@
 WiFiClient client;
 HADevice device;
 HAMqtt mqtt(client, device);
-HASwitch led("led", false, mqtt); // you can use custom name in place of "led"
+HASwitch led("led", false); // "led" is unique ID of the switch. You should define your own ID.

 void onSwitchStateChanged(bool state, HASwitch* s)
 {
@@ -43,6 +43,7 @@ void setup() {

    // handle switch state
    led.onStateChanged(onSwitchStateChanged);
+    led.setName("My LED"); // optional

    mqtt.begin(BROKER_ADDR);
 }
@@ -9,7 +9,13 @@
 WiFiClient client;
 HADevice device;
 HAMqtt mqtt(client, device);
-HASwitch led("led", false, mqtt); // you can use custom name in place of "led"
+HASwitch led("led", false); // "led" is unique ID of the switch. You should define your own ID.
+
+void onBeforeSwitchStateChanged(bool state, HASwitch* s)
+{
+    // this callback will be called before publishing new state to HA
+    // in some cases there may be delay before onStateChanged is called due to network latency
+}

 void onSwitchStateChanged(bool state, HASwitch* s)
 {
@@ -42,7 +48,9 @@ void setup() {
    device.setSoftwareVersion("1.0.0");

    // handle switch state
+    led.onBeforeStateChanged(onBeforeSwitchStateChanged); // optional
    led.onStateChanged(onSwitchStateChanged);
+    led.setName("My LED"); // optional

    mqtt.begin(BROKER_ADDR);
 }
@@ -10,21 +10,13 @@ double lastValue = 0;
 EthernetClient client;
 HADevice device(mac, sizeof(mac));
 HAMqtt mqtt(client, device);
+HASensor temp("temp"); // "temp" is unique ID of the sensor. You should define your own ID.

-/**
- * Supported data types:
- * - uint8_t
- * - uint16_t
- * - uint32_t
- * - int8_t
- * - int16_t
- * - int32_t
- * - double
- * - float
- */
-// you can use custom name in place of "temp"
-// "0" is initial value of the sensor
-HASensor<double> temp("temp", 0, mqtt);
+void onBeforeSwitchStateChanged(bool state, HASwitch* s)
+{
+    // this callback will be called before publishing new state to HA
+    // in some cases there may be delay before onStateChanged is called due to network latency
+}

 void setup() {
    // you don't need to verify return status
@@ -34,8 +26,11 @@ void setup() {
    device.setName("Arduino");
    device.setSoftwareVersion("1.0.0");

-    // you can set custom units for the sensor (optional)
+    // configure sensor (optional)
    temp.setUnitOfMeasurement("°C");
+    temp.setDeviceClass("temperature");
+    temp.setIcon("mdi:home");
+    temp.setName("Home temperature");

    mqtt.begin(BROKER_ADDR);
 }
@@ -48,5 +43,12 @@ void loop() {
        lastSentAt = millis();
        lastValue = lastValue + 0.5;
        temp.setValue(lastValue);
+
+        // Supported data types:
+        // uint32_t (uint16_t, uint8_t)
+        // int32_t (int16_t, int8_t)
+        // double
+        // float
+        // const char*
    }
 }
@@ -1,5 +1,5 @@
 name=home-assistant-integration
-version=1.1.1
+version=1.3.0
 author=Dawid Chyrzynski <dawid.chyrzynski@gmail.com>
 maintainer=Dawid Chyrzynski <dawid.chyrzynski@gmail.com>
 sentence=Home Assistant MQTT integration for Arduino
@@ -5,8 +5,10 @@
 #include "HAMqtt.h"
 #include "HAUtils.h"
 #include "device-types/HABinarySensor.h"
+#include "device-types/HACover.h"
+#include "device-types/HAFan.h"
+#include "device-types/HAHVAC.h"
 #include "device-types/HASensor.h"
-#include "device-types/HASensor.cpp"
 #include "device-types/HASwitch.h"
 #include "device-types/HATagScanner.h"
 #include "device-types/HATriggers.h"
@@ -2,3 +2,22 @@
 // Please note that you need to initialize serial interface manually
 // by calling Serial.begin([baudRate]) before initializing ArduinoHA.
 // #define ARDUINOHA_DEBUG
+
+// You can reduce Flash size of the compiled library by commenting unused components below
+#define ARDUINOHA_BINARY_SENSOR
+#define ARDUINOHA_COVER
+#define ARDUINOHA_FAN
+#define ARDUINOHA_HVAC
+#define ARDUINOHA_SENSOR
+#define ARDUINOHA_SWITCH
+#define ARDUINOHA_TAG_SCANNER
+#define ARDUINOHA_TRIGGERS
+
+#ifdef __GNUC__
+#define AHA_DEPRECATED(func) func __attribute__ ((deprecated))
+#elif defined(_MSC_VER)
+#define AHA_DEPRECATED(func) __declspec(deprecated) func
+#else
+#warning "Arduino Home Assistant: You may miss deprecation warnings."
+#define AHA_DEPRECATED(func) func
+#endif
@@ -1,13 +1,19 @@
 #include <Arduino.h>

+#include "ArduinoHADefines.h"
 #include "HADevice.h"
 #include "HAUtils.h"
+#include "HAMqtt.h"
+#include "device-types/DeviceTypeSerializer.h"

 #define HADEVICE_INIT \
    _manufacturer(nullptr), \
    _model(nullptr), \
    _name(nullptr), \
-    _softwareVersion(nullptr)
+    _softwareVersion(nullptr), \
+    _sharedAvailability(false), \
+    _availabilityTopic(nullptr), \
+    _available(true) // device will be available by default

 HADevice::HADevice() :
    _uniqueId(nullptr),
@@ -30,6 +36,58 @@ HADevice::HADevice(const byte* uniqueId, const uint16_t& length) :

 }

+void HADevice::setAvailability(bool online)
+{
+    _available = online;
+    publishAvailability();
+}
+
+bool HADevice::enableSharedAvailability()
+{
+    if (_sharedAvailability) {
+        return false;
+    }
+
+#if defined(ARDUINOHA_DEBUG)
+    Serial.println(F("Enabling shared availability in the device"));
+#endif
+
+    const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
+        nullptr,
+        nullptr,
+        DeviceTypeSerializer::AvailabilityTopic
+    );
+    if (topicSize == 0) {
+        return false;
+    }
+
+    _availabilityTopic = (char*)malloc(topicSize);
+    _sharedAvailability = true;
+
+    DeviceTypeSerializer::generateTopic(
+        _availabilityTopic,
+        nullptr,
+        nullptr,
+        DeviceTypeSerializer::AvailabilityTopic
+    );
+    return true;
+}
+
+bool HADevice::enableLastWill()
+{
+    HAMqtt* mqtt = HAMqtt::instance();
+    if (mqtt == nullptr || _availabilityTopic == nullptr) {
+        return false;
+    }
+
+    mqtt->setLastWill(
+        _availabilityTopic,
+        DeviceTypeSerializer::Offline,
+        false
+    );
+    return true;
+}
+
 bool HADevice::setUniqueId(const byte* uniqueId, const uint16_t& length)
 {
    if (_uniqueId != nullptr) {
@@ -40,6 +98,28 @@ bool HADevice::setUniqueId(const byte* uniqueId, const uint16_t& length)
    return true;
 }

+void HADevice::publishAvailability()
+{
+    if (!_sharedAvailability) {
+        return;
+    }
+
+    HAMqtt* mqtt = HAMqtt::instance();
+    if (mqtt == nullptr) {
+        return;
+    }
+
+    mqtt->publish(
+        _availabilityTopic,
+        (
+            _available ?
+            DeviceTypeSerializer::Online :
+            DeviceTypeSerializer::Offline
+        ),
+        true
+    );
+}
+
 uint16_t HADevice::calculateSerializedLength() const
 {
    uint16_t size =
@@ -25,7 +25,17 @@ public:
    inline void setSoftwareVersion(const char* softwareVersion)
        { _softwareVersion = softwareVersion; }

+    inline bool isSharedAvailabilityEnabled() const
+        { return _sharedAvailability; }
+
+    inline bool isOnline() const
+        { return _available; }
+
+    void setAvailability(bool online);
+    bool enableSharedAvailability();
+    bool enableLastWill();
    bool setUniqueId(const byte* uniqueId, const uint16_t& length);
+    void publishAvailability();
    uint16_t calculateSerializedLength() const;
    uint16_t serialize(char* dst) const;

@@ -35,6 +45,9 @@ private:
    const char* _model;
    const char* _name;
    const char* _softwareVersion;
+    bool _sharedAvailability;
+    char* _availabilityTopic;
+    bool _available;
 };

 #endif
@@ -5,43 +5,38 @@
 #include "ArduinoHADefines.h"
 #include "device-types/BaseDeviceType.h"

-#define HAMQTT_INIT \
-    _netClient(netClient), \
-    _device(device), \
-    _hasDevice(true), \
-    _initialized(false), \
-    _discoveryPrefix(DefaultDiscoveryPrefix), \
-    _mqtt(new PubSubClient(netClient)), \
-    _serverIp(new IPAddress()), \
-    _serverPort(0), \
-    _username(nullptr), \
-    _password(nullptr), \
-    _lastConnectionAttemptAt(0), \
-    _devicesTypesNb(0), \
-    _devicesTypes(nullptr)
-
 static const char* DefaultDiscoveryPrefix = "homeassistant";
-static HAMqtt* instance = nullptr;
+HAMqtt* HAMqtt::_instance = nullptr;

 void onMessageReceived(char* topic, uint8_t* payload, unsigned int length)
 {
-    if (instance == nullptr || length > UINT16_MAX) {
+    if (HAMqtt::instance() == nullptr || length > UINT16_MAX) {
        return;
    }

-    instance->processMessage(topic, payload, static_cast<uint16_t>(length));
+    HAMqtt::instance()->processMessage(topic, payload, static_cast<uint16_t>(length));
 }

 HAMqtt::HAMqtt(Client& netClient, HADevice& device) :
-    HAMQTT_INIT
+    _netClient(netClient),
+    _device(device),
+    _messageCallback(nullptr),
+    _connectedCallback(nullptr),
+    _connectionFailedCallback(nullptr),
+    _initialized(false),
+    _discoveryPrefix(DefaultDiscoveryPrefix),
+    _dataPrefix(nullptr),
+    _mqtt(new PubSubClient(netClient)),
+    _username(nullptr),
+    _password(nullptr),
+    _lastConnectionAttemptAt(0),
+    _devicesTypesNb(0),
+    _devicesTypes(nullptr),
+    _lastWillTopic(nullptr),
+    _lastWillMessage(nullptr),
+    _lastWillRetain(false)
 {
-    instance = this;
-}
-
-HAMqtt::HAMqtt(const char* clientId, Client& netClient, HADevice& device) :
-    HAMQTT_INIT
-{
-    instance = this;
+    _instance = this;
 }

 bool HAMqtt::begin(
@@ -76,13 +71,11 @@ bool HAMqtt::begin(
        return false;
    }

-    *_serverIp = serverIp;
-    _serverPort = serverPort;
    _username = username;
    _password = password;
    _initialized = true;

-    _mqtt->setServer(*_serverIp, _serverPort);
+    _mqtt->setServer(serverIp, serverPort);
    _mqtt->setCallback(onMessageReceived);

    return true;
@@ -94,16 +87,86 @@ bool HAMqtt::begin(
    const char* password
 )
 {
-    return begin(serverIp, 1883, username, password);
+    return begin(serverIp, HAMQTT_DEFAULT_PORT, username, password);
+}
+
+bool HAMqtt::begin(
+    const char* hostname,
+    const uint16_t& serverPort,
+    const char* username,
+    const char* password
+)
+{
+#if defined(ARDUINOHA_DEBUG)
+    Serial.println(F("Initializing ArduinoHA"));
+    Serial.print(F("Server address: "));
+    Serial.print(hostname);
+    Serial.print(F(":"));
+    Serial.print(serverPort);
+    Serial.println();
+#endif
+
+    if (_device.getUniqueId() == nullptr) {
+#if defined(ARDUINOHA_DEBUG)
+        Serial.println(F("Failed to initialize ArduinoHA. Missing device's unique ID."));
+#endif
+
+        return false;
+    }
+
+    if (_initialized) {
+#if defined(ARDUINOHA_DEBUG)
+    Serial.println(F("ArduinoHA is already initialized"));
+#endif
+
+        return false;
+    }
+
+    _username = username;
+    _password = password;
+    _initialized = true;
+
+    _mqtt->setServer(hostname, serverPort);
+    _mqtt->setCallback(onMessageReceived);
+
+    return true;
+}
+
+bool HAMqtt::begin(
+    const char* hostname,
+    const char* username,
+    const char* password
+)
+{
+    return begin(hostname, HAMQTT_DEFAULT_PORT, username, password);
+}
+
+bool HAMqtt::disconnect(bool sendLastWill)
+{
+    if (!_initialized) {
+        return false;
+    }
+
+#if defined(ARDUINOHA_DEBUG)
+    Serial.println(F("Closing connection with MQTT broker"));
+#endif
+
+    if (sendLastWill &&
+            _lastWillTopic != nullptr &&
+            _lastWillMessage != nullptr) {
+        publish(_lastWillTopic, _lastWillMessage, _lastWillRetain);
+    }
+
+    _initialized = false;
+    _lastConnectionAttemptAt = 0;
+    _mqtt->disconnect();
+
+    return true;
 }

 void HAMqtt::loop()
 {
-    if (!_initialized) {
-        return;
-    }
-
-    if (!_mqtt->loop()) {
+    if (_initialized && !_mqtt->loop()) {
        connectToServer();
    }
 }
@@ -134,9 +197,9 @@ bool HAMqtt::publish(const char* topic, const char* payload, bool retained)
    }

 #if defined(ARDUINOHA_DEBUG)
-    Serial.print(F("Publishing message with topic: "));
+    Serial.print(F("Publishing: "));
    Serial.print(topic);
-    Serial.print(F(", payload length: "));
+    Serial.print(F(", len: "));
    Serial.print(strlen(payload));
    Serial.println();
 #endif
@@ -153,9 +216,9 @@ bool HAMqtt::beginPublish(
 )
 {
 #if defined(ARDUINOHA_DEBUG)
-    Serial.print(F("Publishing message with topic: "));
+    Serial.print(F("Publishing: "));
    Serial.print(topic);
-    Serial.print(F(", payload length: "));
+    Serial.print(F(", len: "));
    Serial.print(payloadLength);
    Serial.println();
 #endif
@@ -202,6 +265,10 @@ void HAMqtt::processMessage(char* topic, uint8_t* payload, uint16_t length)
    Serial.println();
 #endif

+    if (_messageCallback) {
+        _messageCallback(topic, payload, length);
+    }
+
    for (uint8_t i = 0; i < _devicesTypesNb; i++) {
        _devicesTypes[i]->onMqttMessage(topic, payload, length);
    }
@@ -222,27 +289,42 @@ void HAMqtt::connectToServer()
    Serial.println();
 #endif

-    if (_username == nullptr || _password == nullptr) {
-        _mqtt->connect(_device.getUniqueId());
-    } else {
-        _mqtt->connect(_device.getUniqueId(), _username, _password);
-    }
+    _mqtt->connect(
+        _device.getUniqueId(),
+        _username,
+        _password,
+        _lastWillTopic,
+        0,
+        _lastWillRetain,
+        _lastWillMessage,
+        true
+    );

    if (isConnected()) {
 #if defined(ARDUINOHA_DEBUG)
        Serial.println(F("Connected to the broker"));
 #endif

-        onConnected();
+        onConnectedLogic();
    } else {
 #if defined(ARDUINOHA_DEBUG)
        Serial.println(F("Failed to connect to the broker"));
+
+        if (_connectionFailedCallback) {
+            _connectionFailedCallback();
+        }
 #endif
    }
 }

-void HAMqtt::onConnected()
+void HAMqtt::onConnectedLogic()
 {
+    if (_connectedCallback) {
+        _connectedCallback();
+    }
+
+    _device.publishAvailability();
+
    for (uint8_t i = 0; i < _devicesTypesNb; i++) {
        _devicesTypes[i]->onMqttConnected();
    }
@@ -4,6 +4,10 @@
 #include <Client.h>
 #include <IPAddress.h>

+#define HAMQTT_CALLBACK(name) void (*name)()
+#define HAMQTT_MESSAGE_CALLBACK(name) void (*name)(const char* topic, const uint8_t* payload, uint16_t length)
+#define HAMQTT_DEFAULT_PORT 1883
+
 class PubSubClient;
 class HADevice;
 class BaseDeviceType;
@@ -13,13 +17,17 @@ class HAMqtt
 public:
    static const uint16_t ReconnectInterval = 5000; // ms

+    inline static HAMqtt* instance()
+        { return _instance; }
+
    HAMqtt(Client& netClient, HADevice& device);
-    HAMqtt(const char* clientId, Client& netClient, HADevice& device);

    /**
     * Sets prefix for Home Assistant discovery.
     * It needs to match prefix set in the HA admin panel.
     * The default prefix is "homeassistant".
+     *
+     * @param prefix
     */
    inline void setDiscoveryPrefix(const char* prefix)
        { _discoveryPrefix = prefix; }
@@ -30,11 +38,50 @@ public:
    inline const char* getDiscoveryPrefix() const
        { return _discoveryPrefix; }

+    /**
+     * Sets prefix that will be used for topics different than discovery.
+     * It may be useful if you want to pass MQTT trafic through bridge.
+     *
+     * @param prefix
+     */
+    inline void setDataPrefix(const char* prefix)
+        { _dataPrefix = prefix; }
+
+    /**
+     * Returns data prefix.
+     */
+    inline const char* getDataPrefix() const
+        { return _dataPrefix; }
+
    /**
     * Returns instance of the device assigned to the HAMqtt class.
     */
    inline HADevice const* getDevice() const
-        { return (_hasDevice ? &_device : nullptr); }
+        { return &_device; }
+
+    /**
+     * Given callback will be called for each received message from the broker.
+     *
+     * @param callback
+     */
+    inline void onMessage(HAMQTT_MESSAGE_CALLBACK(callback))
+        { _messageCallback = callback; }
+
+    /**
+     * Given callback will be called each time the connection with broker is acquired.
+     *
+     * @param callback
+     */
+    inline void onConnected(HAMQTT_CALLBACK(callback))
+        { _connectedCallback = callback; }
+
+    /**
+     * Given callback will be called each time the library fails to connect to the broker.
+     *
+     * @param callback
+     */
+    inline void onConnectionFailed(HAMQTT_CALLBACK(callback))
+        { _connectionFailedCallback = callback; }

    /**
     * Sets parameters of the connection to the MQTT broker.
@@ -48,27 +95,43 @@ public:
     */
    bool begin(
        const IPAddress& serverIp,
-        const uint16_t& serverPort = 1883,
+        const uint16_t& serverPort = HAMQTT_DEFAULT_PORT,
        const char* username = nullptr,
        const char* password = nullptr
    );
-
-    /**
-     * Sets parameters of the connection to the MQTT broker on default port.
-     * The library will try to connect to the broker in first loop cycle.
-     * Please note that the library automatically reconnects to the broker if connection is lost.
-     *
-     * @param serverIp IP address of the MQTT broker.
-     * @param serverPort Port of the MQTT broker.
-     * @param username Username for authentication.
-     * @param password Password for authentication.
-     */
    bool begin(
        const IPAddress& serverIp,
        const char* username,
        const char* password
    );

+    /**
+     * Connects to the MQTT broker using hostname.
+     *
+     * @param hostname Hostname of the MQTT broker.
+     * @param serverPort Port of the MQTT broker.
+     * @param username Username for authentication.
+     * @param password Password for authentication.
+     */
+    bool begin(
+        const char* hostname,
+        const uint16_t& serverPort = HAMQTT_DEFAULT_PORT,
+        const char* username = nullptr,
+        const char* password = nullptr
+    );
+    bool begin(
+        const char* hostname,
+        const char* username,
+        const char* password
+    );
+
+    /**
+     * Closes connection with the MQTT broker.
+     *
+     * @param sendLastWill Set to true if you want to publish device unavailability before closing the connection.
+     */
+    bool disconnect(bool sendLastWill = true);
+
    /**
     * ArduinoHA's ticker.
     */
@@ -116,6 +179,25 @@ public:
     */
    bool subscribe(const char* topic);

+    /**
+     * Enables last will message that will be produced when device disconnects from the broker.
+     * If you want to change availability of the device in Home Assistant panel
+     * please use enableLastWill() method in the HADevice object instead.
+     *
+     * @param lastWillTopic
+     * @param lastWillMessage
+     * @param lastWillRetain
+     */
+    inline void setLastWill(
+        const char* lastWillTopic,
+        const char* lastWillMessage,
+        bool lastWillRetain
+    ) {
+        _lastWillTopic = lastWillTopic;
+        _lastWillMessage = lastWillMessage;
+        _lastWillRetain = lastWillRetain;
+    }
+
    /**
     * Processes MQTT message received from the broker (subscription).
     *
@@ -126,6 +208,8 @@ public:
    void processMessage(char* topic, uint8_t* payload, uint16_t length);

 private:
+    static HAMqtt* _instance;
+
    /**
     * Attempts to connect to the MQTT broker.
     * The method uses properties passed to the "begin" method.
@@ -135,21 +219,25 @@ private:
    /**
     * This method is called each time the connection with MQTT broker is acquired.
     */
-    void onConnected();
+    void onConnectedLogic();

    Client& _netClient;
    HADevice& _device;
-    bool _hasDevice;
+    HAMQTT_MESSAGE_CALLBACK(_messageCallback);
+    HAMQTT_CALLBACK(_connectedCallback);
+    HAMQTT_CALLBACK(_connectionFailedCallback);
    bool _initialized;
    const char* _discoveryPrefix;
+    const char* _dataPrefix;
    PubSubClient* _mqtt;
-    IPAddress* _serverIp;
-    uint16_t _serverPort;
    const char* _username;
    const char* _password;
    uint32_t _lastConnectionAttemptAt;
    uint8_t _devicesTypesNb;
    BaseDeviceType** _devicesTypes;
+    const char* _lastWillTopic;
+    const char* _lastWillMessage;
+    bool _lastWillRetain;
 };

 #endif
@@ -1,3 +1,7 @@
+#ifdef ARDUINO_ARCH_SAMD
+#include <avr/dtostrf.h>
+#endif
+
 #include <Arduino.h>

 #include "HAUtils.h"
@@ -46,34 +50,18 @@ char* HAUtils::byteArrayToStr(
    return dst;
 }

-uint8_t HAUtils::getValueTypeLength(const ValueType& type)
+void HAUtils::tempToStr(
+    char* dst,
+    const double& temp
+)
 {
-    switch(type) {
-        case ValueTypeUint8:
-            return sizeof(uint8_t);
-
-        case ValueTypeUint16:
-            return sizeof(uint16_t);
-
-        case ValueTypeUint32:
-            return sizeof(uint32_t);
-
-        case ValueTypeInt8:
-            return sizeof(int8_t);
-
-        case ValueTypeInt16:
-            return sizeof(int16_t);
-
-        case ValueTypeInt32:
-            return sizeof(int32_t);
-
-        case ValueTypeDouble:
-            return sizeof(double);
-
-        case ValueTypeFloat:
-            return sizeof(float);
-
-        default:
-            return 0;
-    }
+    memset(dst, 0, sizeof(AHA_SERIALIZED_TEMP_SIZE));
+    dtostrf(temp, 0, 2, dst);
+}
+
+double HAUtils::strToTemp(
+    const char* src
+)
+{
+    return atof(src);
 }
@@ -3,24 +3,14 @@

 #include <Arduino.h>

+#define AHA_SERIALIZED_TEMP_SIZE 8
+
 class HAUtils
 {
 public:
-    enum ValueType {
-        ValueTypeUnknown = -1,
-        ValueTypeUint8,
-        ValueTypeUint16,
-        ValueTypeUint32,
-        ValueTypeInt8,
-        ValueTypeInt16,
-        ValueTypeInt32,
-        ValueTypeDouble,
-        ValueTypeFloat
-    };
-
    static bool endsWith(
        const char* str,
-        const char* suffi
+        const char* suffix
    );
    static void byteArrayToStr(
        char* dst,
@@ -31,28 +21,13 @@ public:
        const byte* src,
        const uint16_t& length
    );
-
-    template <typename A, typename B >
-    static bool compareType(A a, B b) { return false; }
-
-    template <typename A, typename B >
-    static bool compareType(A a, A b) { return true; }
-
-    template <typename T>
-    static ValueType determineValueType() {
-        if (compareType<T, uint8_t>(0, (uint8_t)0)) return ValueTypeUint8;
-        else if (compareType<T, uint16_t>(0, (uint16_t)0)) return ValueTypeUint16;
-        else if (compareType<T, uint32_t>(0, (uint32_t)0)) return ValueTypeUint32;
-        else if (compareType<T, int8_t>(0, (int8_t)0)) return ValueTypeInt8;
-        else if (compareType<T, int16_t>(0, (int16_t)0)) return ValueTypeInt16;
-        else if (compareType<T, int32_t>(0, (int32_t)0)) return ValueTypeInt32;
-        else if (compareType<T, double>(0, (double)0)) return ValueTypeDouble;
-        else if (compareType<T, float>(0, (float)0)) return ValueTypeFloat;
-
-        return ValueTypeUnknown;
-    }
-
-    static uint8_t getValueTypeLength(const ValueType& type);
+    static void tempToStr(
+        char* dst,
+        const double& temp
+    );
+    static double strToTemp(
+        const char* src
+    );
 };

 #endif
@@ -1,18 +1,18 @@
 #include "BaseDeviceType.h"
 #include "../HAMqtt.h"
 #include "../HADevice.h"
+#include "../HAUtils.h"

 BaseDeviceType::BaseDeviceType(
-    HAMqtt& mqtt,
    const char* componentName,
-    const char* name
+    const char* uniqueId
 ) :
-    _mqtt(mqtt),
    _componentName(componentName),
-    _name(name),
-    _availability(AvailabilityDefault)
+    _uniqueId(uniqueId),
+    _availability(AvailabilityDefault),
+    _name(nullptr)
 {
-    _mqtt.addDeviceType(this);
+    mqtt()->addDeviceType(this);
 }

 BaseDeviceType::~BaseDeviceType()
@@ -26,19 +26,89 @@ void BaseDeviceType::setAvailability(bool online)
    publishAvailability();
 }

+HAMqtt* BaseDeviceType::mqtt() const
+{
+    return HAMqtt::instance();
+}
+
+void BaseDeviceType::onMqttMessage(
+    const char* topic,
+    const uint8_t* payload,
+    const uint16_t& length
+)
+{
+    (void)topic;
+    (void)payload;
+    (void)length;
+}
+
+void BaseDeviceType::publishConfig()
+{
+    const HADevice* device = mqtt()->getDevice();
+    if (device == nullptr) {
+        return;
+    }
+
+    const uint16_t& deviceLength = device->calculateSerializedLength();
+    if (deviceLength == 0) {
+        return;
+    }
+
+    char serializedDevice[deviceLength];
+    if (device->serialize(serializedDevice) == 0) {
+        return;
+    }
+
+    const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
+        componentName(),
+        uniqueId(),
+        DeviceTypeSerializer::ConfigTopic,
+        true,
+        true
+    );
+    const uint16_t& dataLength = calculateSerializedLength(serializedDevice);
+
+    if (topicLength == 0 || dataLength == 0) {
+        return;
+    }
+
+    char topic[topicLength];
+    DeviceTypeSerializer::generateTopic(
+        topic,
+        componentName(),
+        uniqueId(),
+        DeviceTypeSerializer::ConfigTopic,
+        true
+    );
+
+    if (strlen(topic) == 0) {
+        return;
+    }
+
+    if (mqtt()->beginPublish(topic, dataLength, true)) {
+        writeSerializedData(serializedDevice);
+        mqtt()->endPublish();
+    }
+}
+
 void BaseDeviceType::publishAvailability()
 {
+    const HADevice* device = HAMqtt::instance()->getDevice();
+    if (device == nullptr) {
+        return;
+    }
+
    if (_availability == AvailabilityDefault ||
-            !_mqtt.isConnected() ||
-            strlen(_name) == 0 ||
-            strlen(_componentName) == 0) {
+            !mqtt()->isConnected() ||
+            strlen(uniqueId()) == 0 ||
+            strlen(componentName()) == 0 ||
+            device->isSharedAvailabilityEnabled()) {
        return;
    }

    const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-        mqtt(),
-        _componentName,
-        _name,
+        componentName(),
+        uniqueId(),
        DeviceTypeSerializer::AvailabilityTopic
    );
    if (topicSize == 0) {
@@ -47,10 +117,9 @@ void BaseDeviceType::publishAvailability()

    char topic[topicSize];
    DeviceTypeSerializer::generateTopic(
-        mqtt(),
        topic,
-        _componentName,
-        _name,
+        componentName(),
+        uniqueId(),
        DeviceTypeSerializer::AvailabilityTopic
    );

@@ -68,3 +137,27 @@ void BaseDeviceType::publishAvailability()
        true
    );
 }
+
+bool BaseDeviceType::compareTopics(const char* topic, const char* expectedTopic)
+{
+    if (topic == nullptr || expectedTopic == nullptr) {
+        return false;
+    }
+
+    if (strlen(uniqueId()) == 0) {
+        return false;
+    }
+
+    static const char Slash[] PROGMEM = {"/"};
+
+    // unique ID + cmd topic + two slashes + null terminator
+    uint8_t suffixLength = strlen(uniqueId()) + strlen(expectedTopic) + 3;
+    char suffix[suffixLength];
+
+    strcpy_P(suffix, Slash);
+    strcat(suffix, uniqueId());
+    strcat_P(suffix, Slash);
+    strcat(suffix, expectedTopic);
+
+    return HAUtils::endsWith(topic, suffix);
+}
@@ -3,6 +3,7 @@

 #include <stdint.h>

+#include "../ArduinoHADefines.h"
 #include "DeviceTypeSerializer.h"

 class HAMqtt;
@@ -11,23 +12,13 @@ class BaseDeviceType
 {
 public:
    BaseDeviceType(
-        HAMqtt& mqtt,
        const char* componentName,
-        const char* name
+        const char* uniqueId
    );
    virtual ~BaseDeviceType();

-    inline bool isOnline() const
-        { return (_availability == AvailabilityOnline); }
-
-    virtual void setAvailability(bool online);
-
-protected:
-    inline HAMqtt* mqtt() const
-        { return &_mqtt; }
-
-    inline const char* name() const
-        { return _name; }
+    inline const char* uniqueId() const
+        { return _uniqueId; }

    inline const char* componentName() const
        { return _componentName; }
@@ -35,17 +26,35 @@ protected:
    inline bool isAvailabilityConfigured() const
        { return (_availability != AvailabilityDefault); }

+    inline bool isOnline() const
+        { return (_availability == AvailabilityOnline); }
+
+    inline void setName(const char* name)
+        { _name = name; }
+
+    inline const char* getName() const
+        { return _name; }
+
+    virtual void setAvailability(bool online);
+
+protected:
+    HAMqtt* mqtt() const;
+
    virtual void onMqttConnected() = 0;
    virtual void onMqttMessage(
        const char* topic,
        const uint8_t* payload,
        const uint16_t& length
-    ) { };
+    );

+    virtual void publishConfig();
    virtual void publishAvailability();
+    virtual bool compareTopics(const char* topic, const char* expectedTopic);
+    virtual uint16_t calculateSerializedLength(const char* serializedDevice) const = 0;
+    virtual bool writeSerializedData(const char* serializedDevice) const = 0;

    const char* const _componentName;
-    const char* const _name;
+    const char* const _uniqueId;

 private:
    enum Availability {
@@ -54,8 +63,8 @@ private:
        AvailabilityOffline
    };

-    HAMqtt& _mqtt;
    Availability _availability;
+    const char* _name;

    friend class HAMqtt;
 };
@@ -1,6 +1,7 @@
 #include <Arduino.h>

 #include "DeviceTypeSerializer.h"
+#include "BaseDeviceType.h"
 #include "../HAMqtt.h"
 #include "../HADevice.h"

@@ -18,32 +19,45 @@ const char* DeviceTypeSerializer::Offline = "offline";
 const char* DeviceTypeSerializer::StateOn = "ON";
 const char* DeviceTypeSerializer::StateOff = "OFF";

+const char* DeviceTypeSerializer::getTopicPrefix(bool isDiscoveryTopic)
+{
+    if (!isDiscoveryTopic) {
+        const char* dataPrefix = HAMqtt::instance()->getDataPrefix();
+        if (dataPrefix != nullptr) {
+            return dataPrefix;
+        }
+    }
+
+    return HAMqtt::instance()->getDiscoveryPrefix();
+}
+
 uint16_t DeviceTypeSerializer::calculateTopicLength(
-    const HAMqtt* mqtt,
    const char* component,
    const char* objectId,
    const char* suffix,
-    bool includeNullTerminator
+    bool includeNullTerminator,
+    bool isDiscoveryTopic
 )
 {
-    const char* prefix = mqtt->getDiscoveryPrefix();
+    const char* prefix = getTopicPrefix(isDiscoveryTopic);
    if (prefix == nullptr) {
        return 0;
    }

    uint16_t size =
-        strlen(prefix) + 1 + // with slash
-        strlen(component) + 1 + // with slash
+        strlen(prefix) + 1 + // prefix with slash
        strlen(suffix);

+    if (component != nullptr) {
+        size += strlen(component) + 1; // component with slash
+    }
+
+    if (HAMqtt::instance()->getDevice() != nullptr) {
+        size += strlen(HAMqtt::instance()->getDevice()->getUniqueId()) + 1; // device ID with slash
+    }
+
    if (objectId != nullptr) {
        size += strlen(objectId) + 1; // with slash
-    } else {
-        size += 1; // slash
-    }
-
-    if (mqtt->getDevice() != nullptr) {
-        size += strlen(mqtt->getDevice()->getUniqueId()) + 1; // with slash
    }

    if (includeNullTerminator) {
@@ -54,26 +68,36 @@ uint16_t DeviceTypeSerializer::calculateTopicLength(
 }

 uint16_t DeviceTypeSerializer::generateTopic(
-    const HAMqtt* mqtt,
    char* output,
    const char* component,
    const char* objectId,
-    const char* suffix
+    const char* suffix,
+    bool isDiscoveryTopic
 )
 {
-    const char* prefix = mqtt->getDiscoveryPrefix();
+    const char* prefix = getTopicPrefix(isDiscoveryTopic);
+    if (prefix == nullptr) {
+        return 0;
+    }
+
    strcpy(output, prefix);
    strcat_P(output, CharSlash);
-    strcat(output, component);
-    strcat_P(output, CharSlash);

-    if (mqtt->getDevice() != nullptr) {
-        strcat(output, mqtt->getDevice()->getUniqueId());
+    if (component != nullptr) {
+        strcat(output, component);
+        strcat_P(output, CharSlash);
+    }
+
+    if (HAMqtt::instance()->getDevice() != nullptr) {
+        strcat(output, HAMqtt::instance()->getDevice()->getUniqueId());
+        strcat_P(output, CharSlash);
+    }
+
+    if (objectId != nullptr) {
+        strcat(output, objectId);
        strcat_P(output, CharSlash);
    }

-    strcat(output, objectId);
-    strcat_P(output, CharSlash);
    strcat(output, suffix);
    return strlen(output) + 1; // size with null terminator
 }
@@ -94,36 +118,39 @@ uint16_t DeviceTypeSerializer::calculateNameFieldSize(const char* name)
 }

 uint16_t DeviceTypeSerializer::calculateUniqueIdFieldSize(
-    const HADevice* device,
-    const char* name
+    const char* uniqueId
 )
 {
-    if (device == nullptr || name == nullptr) {
+    HADevice const* device = HAMqtt::instance()->getDevice();
+    if (device == nullptr || uniqueId == nullptr) {
        return 0;
    }

-    // Field format: ,"uniq_id":"[DEVICE ID]_[NAME]"
+    // Field format: ,"uniq_id":"[DEVICE ID]_[UNIQUE ID]"
    return (
        strlen(device->getUniqueId()) +
-        strlen(name) +
+        strlen(uniqueId) +
        14 // 14 - length of the JSON decorators for this field
    );
 }

 uint16_t DeviceTypeSerializer::calculateAvailabilityFieldSize(
-    const HAMqtt* mqtt,
-    const char* componentName,
-    const char* name
+    const BaseDeviceType* const dt
 )
 {
-    if (mqtt == nullptr || componentName == nullptr || name == nullptr) {
+    const HADevice* device = HAMqtt::instance()->getDevice();
+    if (device == nullptr) {
+        return 0;
+    }
+
+    const bool& sharedAvailability = device->isSharedAvailabilityEnabled();
+    if (!sharedAvailability && !dt->isAvailabilityConfigured()) {
        return 0;
    }

    const uint16_t& availabilityTopicLength = calculateTopicLength(
-        mqtt,
-        componentName,
-        name,
+        (sharedAvailability ? nullptr : dt->componentName()),
+        (sharedAvailability ? nullptr : dt->uniqueId()),
        AvailabilityTopic,
        false
    );
@@ -136,6 +163,16 @@ uint16_t DeviceTypeSerializer::calculateAvailabilityFieldSize(
    return availabilityTopicLength + 12; // 12 - length of the JSON decorators for this field
 }

+uint16_t DeviceTypeSerializer::calculateRetainFieldSize(bool retain)
+{
+    if (!retain) {
+        return 0;
+    }
+
+    // Field format: ,"ret":true
+    return 11;
+}
+
 uint16_t DeviceTypeSerializer::calculateDeviceFieldSize(
    const char* serializedDevice
 )
@@ -148,85 +185,87 @@ uint16_t DeviceTypeSerializer::calculateDeviceFieldSize(
    return strlen(serializedDevice) + 7; // 7 - length of the JSON decorators for this field
 }

-void DeviceTypeSerializer::mqttWriteBeginningJson(HAMqtt* mqtt)
+void DeviceTypeSerializer::mqttWriteBeginningJson()
 {
-    if (mqtt == nullptr) {
-        return;
-    }
-
    static const char Data[] PROGMEM = {"{"};
-    mqtt->writePayload_P(Data);
+    HAMqtt::instance()->writePayload_P(Data);
 }

-void DeviceTypeSerializer::mqttWriteEndJson(HAMqtt* mqtt)
+void DeviceTypeSerializer::mqttWriteEndJson()
 {
-    if (mqtt == nullptr) {
-        return;
-    }
-
    static const char Data[] PROGMEM = {"}"};
-    mqtt->writePayload_P(Data);
+    HAMqtt::instance()->writePayload_P(Data);
 }

 void DeviceTypeSerializer::mqttWriteConstCharField(
-    HAMqtt* mqtt,
    const char* prefix,
-    const char* value
+    const char* value,
+    bool quoteSuffix
 )
 {
-    if (mqtt == nullptr || prefix == nullptr || value == nullptr) {
+    if (prefix == nullptr || value == nullptr) {
        return;
    }

-    mqtt->writePayload_P(prefix);
-    mqtt->writePayload(value, strlen(value));
-    mqtt->writePayload_P(CharQuotation);
+    HAMqtt::instance()->writePayload_P(prefix);
+    HAMqtt::instance()->writePayload(value, strlen(value));
+
+    if (quoteSuffix) {
+        HAMqtt::instance()->writePayload_P(CharQuotation);
+    }
 }

-void DeviceTypeSerializer::mqttWriteNameField(HAMqtt* mqtt, const char* name)
+void DeviceTypeSerializer::mqttWriteNameField(const char* name)
 {
-    if (mqtt == nullptr || name == nullptr) {
+    if (name == nullptr) {
        return;
    }

    static const char Prefix[] PROGMEM = {",\"name\":\""};
-    mqttWriteConstCharField(mqtt, Prefix, name);
+    mqttWriteConstCharField(Prefix, name);
 }

 void DeviceTypeSerializer::mqttWriteUniqueIdField(
-    HAMqtt* mqtt,
-    const char* name
+    const char* uniqueId
 )
 {
-    if (mqtt == nullptr || name == nullptr) {
+    if (uniqueId == nullptr) {
+        return;
+    }
+
+    HADevice const* device = HAMqtt::instance()->getDevice();
+    if (device == nullptr) {
        return;
    }

    static const char Prefix[] PROGMEM = {",\"uniq_id\":\""};

-    uint8_t uniqueIdLength = strlen(name) + strlen(mqtt->getDevice()->getUniqueId()) + 2; // underscore and null temrinator
-    char uniqueId[uniqueIdLength];
-    strcpy(uniqueId, name);
-    strcat_P(uniqueId, CharUnderscore);
-    strcat(uniqueId, mqtt->getDevice()->getUniqueId());
+    uint8_t uniqueIdLength = strlen(uniqueId) + strlen(device->getUniqueId()) + 2; // underscore + null temrinator
+    char finalUniqueId[uniqueIdLength];
+    strcpy(finalUniqueId, uniqueId);
+    strcat_P(finalUniqueId, CharUnderscore);
+    strcat(finalUniqueId, device->getUniqueId());

-    mqttWriteConstCharField(mqtt, Prefix, uniqueId);
+    mqttWriteConstCharField(Prefix, finalUniqueId);
 }

 void DeviceTypeSerializer::mqttWriteAvailabilityField(
-    HAMqtt* mqtt,
-    const char* componentName,
-    const char* name
+    const BaseDeviceType* const dt
 )
 {
-    if (mqtt == nullptr || componentName == nullptr || name == nullptr) {
+    const HADevice* device = HAMqtt::instance()->getDevice();
+    if (device == nullptr) {
+        return;
+    }
+
+    const bool& sharedAvailability = device->isSharedAvailabilityEnabled();
+    if (!sharedAvailability && !dt->isAvailabilityConfigured()) {
        return;
    }

    const uint16_t& topicSize = calculateTopicLength(
-        mqtt,
-        componentName,
-        name,
+        (sharedAvailability ? nullptr : dt->componentName()),
+        (sharedAvailability ? nullptr : dt->uniqueId()),
        AvailabilityTopic
    );
    if (topicSize == 0) {
@@ -235,10 +274,9 @@ void DeviceTypeSerializer::mqttWriteAvailabilityField(

    char availabilityTopic[topicSize];
    generateTopic(
-        mqtt,
        availabilityTopic,
-        componentName,
-        name,
+        (sharedAvailability ? nullptr : dt->componentName()),
+        (sharedAvailability ? nullptr : dt->uniqueId()),
        AvailabilityTopic
    );

@@ -247,20 +285,137 @@ void DeviceTypeSerializer::mqttWriteAvailabilityField(
    }

    static const char Prefix[] PROGMEM = {",\"avty_t\":\""};
-    mqttWriteConstCharField(mqtt, Prefix, availabilityTopic);
+    mqttWriteConstCharField(Prefix, availabilityTopic);
+}
+
+void DeviceTypeSerializer::mqttWriteRetainField(
+    bool retain
+)
+{
+    if (!retain) {
+        return;
+    }
+
+    static const char Prefix[] PROGMEM = {",\"ret\":"};
+    mqttWriteConstCharField(
+        Prefix,
+        "true",
+        false
+    );
 }

 void DeviceTypeSerializer::mqttWriteDeviceField(
-    HAMqtt* mqtt,
    const char* serializedDevice
 )
 {
-    if (mqtt == nullptr || serializedDevice == nullptr) {
+    if (serializedDevice == nullptr) {
        return;
    }

    static const char Data[] PROGMEM = {",\"dev\":"};

-    mqtt->writePayload_P(Data);
-    mqtt->writePayload(serializedDevice, strlen(serializedDevice));
+    HAMqtt::instance()->writePayload_P(Data);
+    HAMqtt::instance()->writePayload(serializedDevice, strlen(serializedDevice));
+}
+
+bool DeviceTypeSerializer::mqttWriteTopicField(
+    const BaseDeviceType* const dt,
+    const char* jsonPrefix,
+    const char* topicSuffix
+)
+{
+    if (jsonPrefix == nullptr || topicSuffix == nullptr) {
+        return false;
+    }
+
+    const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
+        dt->componentName(),
+        dt->uniqueId() ,
+        topicSuffix
+    );
+    if (topicSize == 0) {
+        return false;
+    }
+
+    char topic[topicSize];
+    DeviceTypeSerializer::generateTopic(
+        topic,
+        dt->componentName(),
+        dt->uniqueId(),
+        topicSuffix
+    );
+
+    if (strlen(topic) == 0) {
+        return false;
+    }
+
+    DeviceTypeSerializer::mqttWriteConstCharField(jsonPrefix, topic);
+    return true;
+}
+
+bool DeviceTypeSerializer::mqttPublishMessage(
+    const BaseDeviceType* const dt,
+    const char* topicSuffix,
+    const char* data
+)
+{
+    if (topicSuffix == nullptr || data == nullptr) {
+        return false;
+    }
+
+    const uint16_t& topicSize = calculateTopicLength(
+        dt->componentName(),
+        dt->uniqueId(),
+        topicSuffix
+    );
+    if (topicSize == 0) {
+        return false;
+    }
+
+    char topic[topicSize];
+    generateTopic(
+        topic,
+        dt->componentName(),
+        dt->uniqueId(),
+        topicSuffix
+    );
+
+    if (strlen(topic) == 0) {
+        return false;
+    }
+
+    return HAMqtt::instance()->publish(
+        topic,
+        data,
+        true
+    );
+}
+
+bool DeviceTypeSerializer::mqttSubscribeTopic(
+    const BaseDeviceType* const dt,
+    const char* topicSuffix
+)
+{
+    const uint16_t& topicSize = calculateTopicLength(
+        dt->componentName(),
+        dt->uniqueId(),
+        topicSuffix
+    );
+    if (topicSize == 0) {
+        return false;
+    }
+
+    char topic[topicSize];
+    generateTopic(
+        topic,
+        dt->componentName(),
+        dt->uniqueId(),
+        topicSuffix
+    );
+
+    if (strlen(topic) == 0) {
+        return false;
+    }
+
+    return HAMqtt::instance()->subscribe(topic);
 }
@@ -3,8 +3,8 @@

 #include <stdint.h>

-class HAMqtt;
 class HADevice;
+class BaseDeviceType;

 class DeviceTypeSerializer
 {
@@ -19,40 +19,44 @@ public:
    static const char* StateOn;
    static const char* StateOff;

+    static const char* getTopicPrefix(bool isDiscoveryTopic);
+
    /**
     * Calculates length of the topic with given parameters.
-     * Topic format: [discovery prefix]/[component]/[objectId]/[suffix]
+     * Topic format: [prefix]/[component]/[deviceId]/[objectId]/[suffix]
     *
     * @param component
     * @param objectId
     * @param suffix
     * @param includeNullTerminator
+     * @param isDiscoveryTopic Determines which prefix will be used for topic.
     */
    static uint16_t calculateTopicLength(
-        const HAMqtt* mqtt,
        const char* component,
        const char* objectId,
        const char* suffix,
-        bool includeNullTerminator = true
+        bool includeNullTerminator = true,
+        bool isDiscoveryTopic = false
    );

    /**
     * Generates topic and saves it to the given buffer.
     * Please note that size of the buffer must be calculated by `calculateTopicLength` method first.
-     * Topic format: [discovery prefix]/[component]/[objectId]/[suffix]
+     * Topic format: [prefix]/[component]/[deviceId]/[objectId]/[suffix]
     *
     * @param output
     * @param component
     * @param objectId
     * @param suffix
     * @param includeNullTerminator
+     * @param isDiscoveryTopic Determines which prefix will be used for topic.
     */
    static uint16_t generateTopic(
-        const HAMqtt* mqtt,
        char* output,
        const char* component,
        const char* objectId,
-        const char* suffix
+        const char* suffix,
+        bool isDiscoveryTopic = false
    );

    static uint16_t calculateBaseJsonDataSize();
@@ -60,39 +64,54 @@ public:
        const char* name
    );
    static uint16_t calculateUniqueIdFieldSize(
-        const HADevice* device,
-        const char* name
+        const char* uniqueId
    );
    static uint16_t calculateAvailabilityFieldSize(
-        const HAMqtt* mqtt,
-        const char* componentName,
-        const char* name
+        const BaseDeviceType* const dt
+    );
+    static uint16_t calculateRetainFieldSize(
+        bool retain
    );
    static uint16_t calculateDeviceFieldSize(
        const char* serializedDevice
    );

-    static void mqttWriteBeginningJson(HAMqtt* mqtt);
-    static void mqttWriteEndJson(HAMqtt* mqtt);
+    static void mqttWriteBeginningJson();
+    static void mqttWriteEndJson();
    static void mqttWriteConstCharField(
-        HAMqtt* mqtt,
        const char* prefix,
-        const char* value
+        const char* value,
+        bool quoteSuffix = true
    );
-    static void mqttWriteNameField(HAMqtt* mqtt, const char* name);
-    static void mqttWriteUniqueIdField(
-        HAMqtt* mqtt,
+    static void mqttWriteNameField(
        const char* name
    );
+    static void mqttWriteUniqueIdField(
+        const char* uniqueId
+    );
    static void mqttWriteAvailabilityField(
-        HAMqtt* mqtt,
-        const char* componentName,
-        const char* name
+        const BaseDeviceType* const dt
+    );
+    static void mqttWriteRetainField(
+        bool retain
    );
    static void mqttWriteDeviceField(
-        HAMqtt* mqtt,
        const char* serializedDevice
    );
+    static bool mqttWriteTopicField(
+        const BaseDeviceType* const dt,
+        const char* jsonPrefix,
+        const char* topicSuffix
+    );
+    static bool mqttPublishMessage(
+        const BaseDeviceType* const dt,
+        const char* topicSuffix,
+        const char* data
+    );
+    static bool mqttSubscribeTopic(
+        const BaseDeviceType* const dt,
+        const char* topicSuffix
+    );
 };

 #endif
@@ -1,15 +1,15 @@
 #include "HABinarySensor.h"
+#ifdef ARDUINOHA_BINARY_SENSOR
+
 #include "../ArduinoHADefines.h"
 #include "../HAMqtt.h"
 #include "../HADevice.h"
-#include "../HAUtils.h"

 HABinarySensor::HABinarySensor(
-    const char* name,
-    bool initialState,
-    HAMqtt& mqtt
+    const char* uniqueId,
+    bool initialState
 ) :
-    BaseDeviceType(mqtt, "binary_sensor", name),
+    BaseDeviceType("binary_sensor", uniqueId),
    _class(nullptr),
    _currentState(initialState)
 {
@@ -17,21 +17,41 @@ HABinarySensor::HABinarySensor(
 }

 HABinarySensor::HABinarySensor(
-    const char* name,
-    const char* deviceClass,
+    const char* uniqueId,
    bool initialState,
    HAMqtt& mqtt
 ) :
-    BaseDeviceType(mqtt, "binary_sensor", name),
+    HABinarySensor(uniqueId, initialState)
+{
+    (void)mqtt;
+}
+
+HABinarySensor::HABinarySensor(
+    const char* uniqueId,
+    const char* deviceClass,
+    bool initialState
+) :
+    BaseDeviceType("binary_sensor", uniqueId),
    _class(deviceClass),
    _currentState(initialState)
 {

 }

+HABinarySensor::HABinarySensor(
+    const char* uniqueId,
+    const char* deviceClass,
+    bool initialState,
+    HAMqtt& mqtt
+) :
+    HABinarySensor(uniqueId, deviceClass, initialState)
+{
+    (void)mqtt;
+}
+
 void HABinarySensor::onMqttConnected()
 {
-    if (strlen(name()) == 0) {
+    if (strlen(uniqueId()) == 0) {
        return;
    }

@@ -46,10 +66,6 @@ bool HABinarySensor::setState(bool state)
        return true;
    }

-    if (strlen(name()) == 0) {
-        return false;
-    }
-
    if (publishState(state)) {
        _currentState = state;
        return true;
@@ -58,64 +74,15 @@ bool HABinarySensor::setState(bool state)
    return false;
 }

-void HABinarySensor::publishConfig()
-{
-    const HADevice* device = mqtt()->getDevice();
-    if (device == nullptr) {
-        return;
-    }
-
-    const uint16_t& deviceLength = device->calculateSerializedLength();
-    if (deviceLength == 0) {
-        return;
-    }
-
-    char serializedDevice[deviceLength];
-    if (device->serialize(serializedDevice) == 0) {
-        return;
-    }
-
-    const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
-        mqtt(),
-        componentName(),
-        name(),
-        DeviceTypeSerializer::ConfigTopic
-    );
-    const uint16_t& dataLength = calculateSerializedLength(serializedDevice);
-
-    if (topicLength == 0 || dataLength == 0) {
-        return;
-    }
-
-    char topic[topicLength];
-    DeviceTypeSerializer::generateTopic(
-        mqtt(),
-        topic,
-        componentName(),
-        name(),
-        DeviceTypeSerializer::ConfigTopic
-    );
-
-    if (strlen(topic) == 0) {
-        return;
-    }
-
-    if (mqtt()->beginPublish(topic, dataLength, true)) {
-        writeSerializedData(serializedDevice);
-        mqtt()->endPublish();
-    }
-}
-
 bool HABinarySensor::publishState(bool state)
 {
-    if (strlen(name()) == 0) {
+    if (strlen(uniqueId()) == 0) {
        return false;
    }

    const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-        mqtt(),
        componentName(),
-        name(),
+        uniqueId(),
        DeviceTypeSerializer::StateTopic
    );
    if (topicSize == 0) {
@@ -124,10 +91,9 @@ bool HABinarySensor::publishState(bool state)

    char topic[topicSize];
    DeviceTypeSerializer::generateTopic(
-        mqtt(),
        topic,
        componentName(),
-        name(),
+        uniqueId(),
        DeviceTypeSerializer::StateTopic
    );

@@ -161,24 +127,16 @@ uint16_t HABinarySensor::calculateSerializedLength(

    uint16_t size = 0;
    size += DeviceTypeSerializer::calculateBaseJsonDataSize();
-    size += DeviceTypeSerializer::calculateNameFieldSize(name());
-    size += DeviceTypeSerializer::calculateUniqueIdFieldSize(device, name());
+    size += DeviceTypeSerializer::calculateNameFieldSize(getName());
+    size += DeviceTypeSerializer::calculateUniqueIdFieldSize(uniqueId());
    size += DeviceTypeSerializer::calculateDeviceFieldSize(serializedDevice);
-
-    if (isAvailabilityConfigured()) {
-        size += DeviceTypeSerializer::calculateAvailabilityFieldSize(
-            mqtt(),
-            componentName(),
-            name()
-        );
-    }
+    size += DeviceTypeSerializer::calculateAvailabilityFieldSize(this);

    // state topic
    {
        const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
-            mqtt(),
            componentName(),
-            name(),
+            uniqueId(),
            DeviceTypeSerializer::StateTopic,
            false
        );
@@ -206,56 +164,31 @@ bool HABinarySensor::writeSerializedData(const char* serializedDevice) const
        return false;
    }

-    DeviceTypeSerializer::mqttWriteBeginningJson(mqtt());
+    DeviceTypeSerializer::mqttWriteBeginningJson();

    // state topic
    {
-        const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-            mqtt(),
-            componentName(),
-            name(),
-            DeviceTypeSerializer::StateTopic
-        );
-        if (topicSize == 0) {
-            return false;
-        }
-
-        char topic[topicSize];
-        DeviceTypeSerializer::generateTopic(
-            mqtt(),
-            topic,
-            componentName(),
-            name(),
-            DeviceTypeSerializer::StateTopic
-        );
-
-        if (strlen(topic) == 0) {
-            return false;
-        }
-
        static const char Prefix[] PROGMEM = {"\"stat_t\":\""};
-        DeviceTypeSerializer::mqttWriteConstCharField(mqtt(), Prefix, topic);
+        DeviceTypeSerializer::mqttWriteTopicField(
+            this,
+            Prefix,
+            DeviceTypeSerializer::StateTopic
+        );
    }

    // device class
    if (_class != nullptr) {
        static const char Prefix[] PROGMEM = {",\"dev_cla\":\""};
-        DeviceTypeSerializer::mqttWriteConstCharField(mqtt(), Prefix, _class);
+        DeviceTypeSerializer::mqttWriteConstCharField(Prefix, _class);
    }

-    DeviceTypeSerializer::mqttWriteNameField(mqtt(), name());
-    DeviceTypeSerializer::mqttWriteUniqueIdField(mqtt(), name());
-
-    if (isAvailabilityConfigured()) {
-        DeviceTypeSerializer::mqttWriteAvailabilityField(
-            mqtt(),
-            componentName(),
-            name()
-        );
-    }
-
-    DeviceTypeSerializer::mqttWriteDeviceField(mqtt(), serializedDevice);
-    DeviceTypeSerializer::mqttWriteEndJson(mqtt());
+    DeviceTypeSerializer::mqttWriteNameField(getName());
+    DeviceTypeSerializer::mqttWriteUniqueIdField(uniqueId());
+    DeviceTypeSerializer::mqttWriteAvailabilityField(this);
+    DeviceTypeSerializer::mqttWriteDeviceField(serializedDevice);
+    DeviceTypeSerializer::mqttWriteEndJson();

    return true;
 }
+
+#endif
@@ -3,33 +3,44 @@

 #include "BaseDeviceType.h"

+#ifdef ARDUINOHA_BINARY_SENSOR
+
 class HABinarySensor : public BaseDeviceType
 {
 public:
    /**
     * Initializes binary sensor.
     *
-     * @param name Name of the sensor. Recommendes characters: [a-z0-9\-_]
+     * @param uniqueId Unique ID of the sensor. Recommended characters: [a-z0-9\-_]
     * @param initialState Initial state of the sensor.
                           It will be published right after "config" message in order to update HA state.
     */
    HABinarySensor(
-        const char* name,
+        const char* uniqueId,
+        bool initialState
+    );
+    HABinarySensor(
+        const char* uniqueId,
        bool initialState,
        HAMqtt& mqtt
-    );
+    ); // legacy constructor

    /**
     * Initializes binary sensor with the specified class.
     * You can find list of available values here: https://www.home-assistant.io/integrations/binary_sensor/#device-class
     *
-     * @param name Name of the sensor. Recommendes characters: [a-z0-9\-_]
+     * @param uniqueId Unique ID of the sensor. Recommendes characters: [a-z0-9\-_]
     * @param deviceClass Name of the class (lower case).
     * @param initialState Initial state of the sensor.
                           It will be published right after "config" message in order to update HA state.
     */
    HABinarySensor(
-        const char* name,
+        const char* uniqueId,
+        const char* deviceClass,
+        bool initialState
+    );
+    HABinarySensor(
+        const char* uniqueId,
        const char* deviceClass,
        bool initialState,
        HAMqtt& mqtt
@@ -58,13 +69,13 @@ public:
        { return _currentState; }

 private:
-    void publishConfig();
    bool publishState(bool state);
-    uint16_t calculateSerializedLength(const char* serializedDevice) const;
-    bool writeSerializedData(const char* serializedDevice) const;
+    uint16_t calculateSerializedLength(const char* serializedDevice) const override;
+    bool writeSerializedData(const char* serializedDevice) const override;

    const char* _class;
    bool _currentState;
 };

 #endif
+#endif
@@ -0,0 +1,286 @@
+#include "HACover.h"
+#ifdef ARDUINOHA_COVER
+
+#include "../HAMqtt.h"
+#include "../HADevice.h"
+
+static const char ClosedStateStr[] PROGMEM = {"closed"};
+static const char ClosingStateStr[] PROGMEM = {"closing"};
+static const char OpenStateStr[] PROGMEM = {"open"};
+static const char OpeningStateStr[] PROGMEM = {"opening"};
+static const char StoppedStateStr[] PROGMEM = {"stopped"};
+static const char OpenCommandStr[] PROGMEM = {"OPEN"};
+static const char CloseCommandStr[] PROGMEM = {"CLOSE"};
+static const char StopCommandStr[] PROGMEM = {"STOP"};
+
+const char* HACover::PositionTopic = "ps";
+
+HACover::HACover(const char* uniqueId) :
+    BaseDeviceType("cover", uniqueId),
+    _commandCallback(nullptr),
+    _currentState(StateUnknown),
+    _currentPosition(0),
+    _retain(false)
+{
+
+}
+
+HACover::HACover(const char* uniqueId, HAMqtt& mqtt) :
+    HACover(uniqueId)
+{
+    (void)mqtt;
+}
+
+void HACover::onMqttConnected()
+{
+    if (strlen(uniqueId()) == 0) {
+        return;
+    }
+
+    publishConfig();
+    publishAvailability();
+
+    DeviceTypeSerializer::mqttSubscribeTopic(
+        this,
+        DeviceTypeSerializer::CommandTopic
+    );
+
+    if (!_retain) {
+        publishState(_currentState);
+        publishPosition(_currentPosition);
+    }
+}
+
+void HACover::onMqttMessage(
+    const char* topic,
+    const uint8_t* payload,
+    const uint16_t& length
+)
+{
+    (void)payload;
+
+    if (compareTopics(topic, DeviceTypeSerializer::CommandTopic)) {
+        char cmd[length + 1];
+        memset(cmd, 0, sizeof(cmd));
+        memcpy(cmd, payload, length);
+        handleCommand(cmd);
+    }
+}
+
+bool HACover::setState(CoverState state, bool force)
+{
+    if (!force && _currentState == state) {
+        return true;
+    }
+
+    if (publishState(state)) {
+        _currentState = state;
+        return true;
+    }
+
+    return false;
+}
+
+bool HACover::setPosition(int16_t position)
+{
+    if (_currentPosition == position) {
+        return true;
+    }
+
+    if (publishPosition(position)) {
+        _currentPosition = position;
+        return true;
+    }
+
+    return false;
+}
+
+bool HACover::publishState(CoverState state)
+{
+    if (strlen(uniqueId()) == 0 || state == StateUnknown) {
+        return false;
+    }
+
+    char stateStr[8];
+    switch (state) {
+        case StateClosed:
+            strcpy_P(stateStr, ClosedStateStr);
+            break;
+
+        case StateClosing:
+            strcpy_P(stateStr, ClosingStateStr);
+            break;
+
+        case StateOpen:
+            strcpy_P(stateStr, OpenStateStr);
+            break;
+
+        case StateOpening:
+            strcpy_P(stateStr, OpeningStateStr);
+            break;
+
+        case StateStopped:
+            strcpy_P(stateStr, StoppedStateStr);
+            break;
+
+        default:
+            return false;
+    }
+
+    return DeviceTypeSerializer::mqttPublishMessage(
+        this,
+        DeviceTypeSerializer::StateTopic,
+        stateStr
+    );
+}
+
+bool HACover::publishPosition(int16_t position)
+{
+    if (strlen(uniqueId()) == 0) {
+        return false;
+    }
+
+    uint8_t digitsNb = floor(log10(position)) + 1;
+    char str[digitsNb + 2]; // + null terminator + negative sign
+    memset(str, 0, sizeof(str));
+    itoa(position, str, 10);
+
+    return DeviceTypeSerializer::mqttPublishMessage(
+        this,
+        PositionTopic,
+        str
+    );
+}
+
+uint16_t HACover::calculateSerializedLength(const char* serializedDevice) const
+{
+    if (serializedDevice == nullptr) {
+        return 0;
+    }
+
+    uint16_t size = 0;
+    size += DeviceTypeSerializer::calculateBaseJsonDataSize();
+    size += DeviceTypeSerializer::calculateNameFieldSize(getName());
+    size += DeviceTypeSerializer::calculateUniqueIdFieldSize(uniqueId());
+    size += DeviceTypeSerializer::calculateDeviceFieldSize(serializedDevice);
+    size += DeviceTypeSerializer::calculateAvailabilityFieldSize(this);
+    size += DeviceTypeSerializer::calculateRetainFieldSize(_retain);
+
+    // command topic
+    {
+        const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
+            componentName(),
+            uniqueId(),
+            DeviceTypeSerializer::CommandTopic,
+            false
+        );
+
+        if (topicLength == 0) {
+            return 0;
+        }
+
+        // Field format: "cmd_t":"[TOPIC]"
+        size += topicLength + 10; // 10 - length of the JSON decorators for this field
+    }
+
+    // state topic
+    {
+        const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
+            componentName(),
+            uniqueId(),
+            DeviceTypeSerializer::StateTopic,
+            false
+        );
+
+        if (topicLength == 0) {
+            return 0;
+        }
+
+        // Field format: ,"stat_t":"[TOPIC]"
+        size += topicLength + 12; // 12 - length of the JSON decorators for this field
+    }
+
+    // position topic
+    {
+        const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
+            componentName(),
+            uniqueId(),
+            PositionTopic,
+            false
+        );
+
+        if (topicLength == 0) {
+            return 0;
+        }
+
+        // Field format: ,"pos_t":"[TOPIC]"
+        size += topicLength + 11; // 11 - length of the JSON decorators for this field
+    }
+
+    return size; // exludes null terminator
+}
+
+bool HACover::writeSerializedData(const char* serializedDevice) const
+{
+    if (serializedDevice == nullptr) {
+        return false;
+    }
+
+    DeviceTypeSerializer::mqttWriteBeginningJson();
+
+    // command topic
+    {
+        static const char Prefix[] PROGMEM = {"\"cmd_t\":\""};
+        DeviceTypeSerializer::mqttWriteTopicField(
+            this,
+            Prefix,
+            DeviceTypeSerializer::CommandTopic
+        );
+    }
+
+    // state topic
+    {
+        static const char Prefix[] PROGMEM = {",\"stat_t\":\""};
+        DeviceTypeSerializer::mqttWriteTopicField(
+            this,
+            Prefix,
+            DeviceTypeSerializer::StateTopic
+        );
+    }
+
+    // position topic
+    {
+        static const char Prefix[] PROGMEM = {",\"pos_t\":\""};
+        DeviceTypeSerializer::mqttWriteTopicField(
+            this,
+            Prefix,
+            PositionTopic
+        );
+    }
+
+    DeviceTypeSerializer::mqttWriteNameField(getName());
+    DeviceTypeSerializer::mqttWriteUniqueIdField(uniqueId());
+    DeviceTypeSerializer::mqttWriteDeviceField(serializedDevice);
+    DeviceTypeSerializer::mqttWriteAvailabilityField(this);
+    DeviceTypeSerializer::mqttWriteRetainField(_retain);
+    DeviceTypeSerializer::mqttWriteEndJson();
+
+    return true;
+}
+
+void HACover::handleCommand(const char* cmd)
+{
+    if (!_commandCallback) {
+        return;
+    }
+
+    if (strcmp_P(cmd, CloseCommandStr) == 0) {
+        _commandCallback(CommandClose);
+    } else if (strcmp_P(cmd, OpenCommandStr) == 0) {
+        _commandCallback(CommandOpen);
+    } else if (strcmp_P(cmd, StopCommandStr) == 0) {
+        _commandCallback(CommandStop);
+    }
+}
+
+#endif
@@ -0,0 +1,113 @@
+#ifndef AHA_COVER_H
+#define AHA_COVER_H
+
+#include "BaseDeviceType.h"
+
+#ifdef ARDUINOHA_COVER
+
+#define HACOVER_CALLBACK(name) void (*name)(CoverCommand cmd)
+
+class HACover : public BaseDeviceType
+{
+public:
+    static const char* PositionTopic;
+
+    enum CoverState {
+        StateUnknown = 0,
+        StateClosed,
+        StateClosing,
+        StateOpen,
+        StateOpening,
+        StateStopped
+    };
+
+    enum CoverCommand {
+        CommandOpen,
+        CommandClose,
+        CommandStop
+    };
+
+    HACover(const char* uniqueId);
+    HACover(const char* uniqueId, HAMqtt& mqtt); // legacy constructor
+
+    virtual void onMqttConnected() override;
+    virtual void onMqttMessage(
+        const char* topic,
+        const uint8_t* payload,
+        const uint16_t& length
+    ) override;
+
+    /**
+     * Changes state of the cover and publishes MQTT message.
+     * Please note that if a new value is the same as previous one,
+     * the MQTT message won't be published.
+     *
+     * @param state New state of the cover.
+     * @param force Forces to update state without comparing it to previous known state.
+     * @returns Returns true if MQTT message has been published successfully.
+     */
+    bool setState(CoverState state, bool force = false);
+
+    /**
+     * Sets current state of the cover without pushing the state to Home Assistant.
+     * This method may be useful if you want to change state before connection
+     * with MQTT broker is acquired.
+     *
+     * @param state New state of the cover.
+     */
+    inline void setCurrentState(CoverState state)
+        { _currentState = state; }
+
+    /**
+     * Changes position of the cover and publishes MQTT message.
+     * Please note that if a new value is the same as previous one,
+     * the MQTT message won't be published.
+     *
+     * @param position New position of the cover.
+     * @returns Returns true if MQTT message has been published successfully.
+     */
+    bool setPosition(int16_t position);
+
+    /**
+     * Sets current position of the cover without pushing the value to Home Assistant.
+     * This method may be useful if you want to change position before connection
+     * with MQTT broker is acquired.
+     *
+     * @param position New position of the cover.
+     */
+    inline void setCurrentPosition(int16_t position)
+        { _currentPosition = position; }
+
+    /**
+     * Sets `retain` flag for commands published by Home Assistant.
+     * By default it's set to false.
+     *
+     * @param retain
+     */
+    inline void setRetain(bool retain)
+        { _retain = retain; }
+
+    /**
+     * Registers callback that will be called each time the command from HA is received.
+     * Please note that it's not possible to register multiple callbacks for the same covers.
+     *
+     * @param callback
+     */
+    inline void onCommand(HACOVER_CALLBACK(callback))
+        { _commandCallback = callback; }
+
+protected:
+    bool publishState(CoverState state);
+    bool publishPosition(int16_t position);
+    uint16_t calculateSerializedLength(const char* serializedDevice) const override;
+    bool writeSerializedData(const char* serializedDevice) const override;
+    void handleCommand(const char* cmd);
+
+    HACOVER_CALLBACK(_commandCallback);
+    CoverState _currentState;
+    int16_t _currentPosition;
+    bool _retain;
+};
+
+#endif
+#endif
@@ -0,0 +1,343 @@
+#include "HAFan.h"
+#ifdef ARDUINOHA_FAN
+
+#include "../HAMqtt.h"
+#include "../HADevice.h"
+
+const char* HAFan::PercentageCommandTopic = {"sct"};
+const char* HAFan::PercentageStateTopic = {"sst"};
+
+HAFan::HAFan(const char* uniqueId, uint8_t features) :
+    BaseDeviceType("fan", uniqueId),
+    _features(features),
+    _currentState(false),
+    _stateCallback(nullptr),
+    _currentSpeed(0),
+    _speedCallback(nullptr),
+    _retain(false),
+    _speedRangeMin(1),
+    _speedRangeMax(100)
+{
+
+}
+
+HAFan::HAFan(const char* uniqueId, uint8_t features, HAMqtt& mqtt) :
+    HAFan(uniqueId, features)
+{
+    (void)mqtt;
+}
+
+void HAFan::onMqttConnected()
+{
+    if (strlen(uniqueId()) == 0) {
+        return;
+    }
+
+    publishConfig();
+    publishAvailability();
+
+    DeviceTypeSerializer::mqttSubscribeTopic(
+        this,
+        DeviceTypeSerializer::CommandTopic
+    );
+
+    if (_features & SpeedsFeature) {
+        DeviceTypeSerializer::mqttSubscribeTopic(
+            this,
+            PercentageCommandTopic
+        );
+    }
+
+    if (!_retain) {
+        publishState(_currentState);
+        publishSpeed(_currentSpeed);
+    }
+}
+
+void HAFan::onMqttMessage(
+    const char* topic,
+    const uint8_t* payload,
+    const uint16_t& length
+)
+{
+    (void)payload;
+
+    if (compareTopics(topic, DeviceTypeSerializer::CommandTopic)) {
+        bool state = (length == strlen(DeviceTypeSerializer::StateOn));
+        setState(state, true);
+    } else if (compareTopics(topic, PercentageCommandTopic)) {
+        char speedStr[length + 1];
+        memset(speedStr, 0, sizeof(speedStr));
+        memcpy(speedStr, payload, length);
+        int32_t speed = atoi(speedStr);
+        if (speed >= 0) {
+            setSpeed(speed);
+        }
+    }
+}
+
+bool HAFan::setState(bool state, bool force)
+{
+    if (!force && _currentState == state) {
+        return true;
+    }
+
+    if (publishState(state)) {
+        _currentState = state;
+
+        if (_stateCallback) {
+            _stateCallback(state);
+        }
+
+        return true;
+    }
+
+    return false;
+}
+
+bool HAFan::setSpeed(uint16_t speed)
+{
+    if (publishSpeed(speed)) {
+        _currentSpeed = speed;
+
+        if (_speedCallback) {
+            _speedCallback(_currentSpeed);
+        }
+
+        return true;
+    }
+
+    return false;
+}
+
+bool HAFan::publishState(bool state)
+{
+    if (strlen(uniqueId()) == 0) {
+        return false;
+    }
+
+    return DeviceTypeSerializer::mqttPublishMessage(
+        this,
+        DeviceTypeSerializer::StateTopic,
+        (
+            state ?
+            DeviceTypeSerializer::StateOn :
+            DeviceTypeSerializer::StateOff
+        )
+    );
+}
+
+bool HAFan::publishSpeed(uint16_t speed)
+{
+    if (strlen(uniqueId()) == 0) {
+        return false;
+    }
+
+    uint8_t digitsNb = floor(log10(speed)) + 1;
+    char str[digitsNb + 1]; // + null terminator
+    memset(str, 0, sizeof(str));
+    itoa(speed, str, 10);
+
+    return DeviceTypeSerializer::mqttPublishMessage(
+        this,
+        PercentageStateTopic,
+        str
+    );
+}
+
+uint16_t HAFan::calculateSerializedLength(const char* serializedDevice) const
+{
+    if (serializedDevice == nullptr) {
+        return 0;
+    }
+
+    uint16_t size = 0;
+    size += DeviceTypeSerializer::calculateBaseJsonDataSize();
+    size += DeviceTypeSerializer::calculateNameFieldSize(getName());
+    size += DeviceTypeSerializer::calculateUniqueIdFieldSize(uniqueId());
+    size += DeviceTypeSerializer::calculateDeviceFieldSize(serializedDevice);
+    size += DeviceTypeSerializer::calculateAvailabilityFieldSize(this);
+    size += DeviceTypeSerializer::calculateRetainFieldSize(_retain);
+
+    // command topic
+    {
+        const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
+            componentName(),
+            uniqueId(),
+            DeviceTypeSerializer::CommandTopic,
+            false
+        );
+
+        if (topicLength == 0) {
+            return 0;
+        }
+
+        // Field format: "cmd_t":"[TOPIC]"
+        size += topicLength + 10; // 10 - length of the JSON decorators for this field
+    }
+
+    // state topic
+    {
+        const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
+            componentName(),
+            uniqueId(),
+            DeviceTypeSerializer::StateTopic,
+            false
+        );
+
+        if (topicLength == 0) {
+            return 0;
+        }
+
+        // Field format: ,"stat_t":"[TOPIC]"
+        size += topicLength + 12; // 12 - length of the JSON decorators for this field
+    }
+
+    // speeds
+    if (_features & SpeedsFeature) {
+        // percentage command topic
+        {
+            const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
+                componentName(),
+                uniqueId(),
+                PercentageCommandTopic,
+                false
+            );
+
+            if (topicLength == 0) {
+                return 0;
+            }
+
+            // Field format: ,"pct_cmd_t":"[TOPIC]"
+            size += topicLength + 15; // 15 - length of the JSON decorators for this field
+        }
+
+        // percentage state topic
+        {
+            const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
+                componentName(),
+                uniqueId(),
+                PercentageStateTopic,
+                false
+            );
+
+            if (topicLength == 0) {
+                return 0;
+            }
+
+            // Field format: ,"pct_stat_t":"[TOPIC]"
+            size += topicLength + 16; // 16 - length of the JSON decorators for this field
+        }
+
+        // speed range min
+        if (_speedRangeMin != 1) {
+            uint8_t digitsNb = floor(log10(_speedRangeMin)) + 1;
+
+            // Field format: ,"spd_rng_min":[VALUE]
+            size += digitsNb + 15; // 15 - length of the JSON decorators for this field
+        }
+
+        // speed range max
+        if (_speedRangeMax != 100) {
+            uint8_t digitsNb = floor(log10(_speedRangeMax)) + 1;
+
+            // Field format: ,"spd_rng_max":[VALUE]
+            size += digitsNb + 15; // 15 - length of the JSON decorators for this field
+        }
+    }
+
+    return size; // excludes null terminator
+}
+
+bool HAFan::writeSerializedData(const char* serializedDevice) const
+{
+    if (serializedDevice == nullptr) {
+        return false;
+    }
+
+    DeviceTypeSerializer::mqttWriteBeginningJson();
+
+    // command topic
+    {
+        static const char Prefix[] PROGMEM = {"\"cmd_t\":\""};
+        DeviceTypeSerializer::mqttWriteTopicField(
+            this,
+            Prefix,
+            DeviceTypeSerializer::CommandTopic
+        );
+    }
+
+    // state topic
+    {
+        static const char Prefix[] PROGMEM = {",\"stat_t\":\""};
+        DeviceTypeSerializer::mqttWriteTopicField(
+            this,
+            Prefix,
+            DeviceTypeSerializer::StateTopic
+        );
+    }
+
+    // speeds
+    if (_features & SpeedsFeature) {
+        // percentage command topic
+        {
+            static const char Prefix[] PROGMEM = {",\"pct_cmd_t\":\""};
+            DeviceTypeSerializer::mqttWriteTopicField(
+                this,
+                Prefix,
+                PercentageCommandTopic
+            );
+        }
+
+        // percentage state topic
+        {
+            static const char Prefix[] PROGMEM = {",\"pct_stat_t\":\""};
+            DeviceTypeSerializer::mqttWriteTopicField(
+                this,
+                Prefix,
+                PercentageStateTopic
+            );
+        }
+
+        // speed range min
+        if (_speedRangeMin != 1) {
+            uint8_t digitsNb = floor(log10(_speedRangeMin)) + 1;
+            char str[digitsNb + 1]; // + null terminator
+            memset(str, 0, sizeof(str));
+            itoa(_speedRangeMin, str, 10);
+
+            static const char Prefix[] PROGMEM = {",\"spd_rng_min\":"};
+            DeviceTypeSerializer::mqttWriteConstCharField(
+                Prefix,
+                str,
+                false
+            );
+        }
+
+        // speed range max
+        if (_speedRangeMax != 100) {
+            uint8_t digitsNb = floor(log10(_speedRangeMax)) + 1;
+            char str[digitsNb + 1]; // + null terminator
+            memset(str, 0, sizeof(str));
+            itoa(_speedRangeMax, str, 10);
+
+            static const char Prefix[] PROGMEM = {",\"spd_rng_max\":"};
+            DeviceTypeSerializer::mqttWriteConstCharField(
+                Prefix,
+                str,
+                false
+            );
+        }
+    }
+
+    DeviceTypeSerializer::mqttWriteNameField(getName());
+    DeviceTypeSerializer::mqttWriteUniqueIdField(uniqueId());
+    DeviceTypeSerializer::mqttWriteDeviceField(serializedDevice);
+    DeviceTypeSerializer::mqttWriteAvailabilityField(this);
+    DeviceTypeSerializer::mqttWriteRetainField(_retain);
+    DeviceTypeSerializer::mqttWriteEndJson();
+
+    return true;
+}
+
+#endif
@@ -0,0 +1,156 @@
+#ifndef AHA_FAN_H
+#define AHA_FAN_H
+
+#include "BaseDeviceType.h"
+
+#ifdef ARDUINOHA_FAN
+
+#define HAFAN_STATE_CALLBACK_BOOL(name) void (*name)(bool)
+#define HAFAN_STATE_CALLBACK_SPEED(name) void (*name)(uint16_t)
+#define HAFAN_STATE_CALLBACK_SPEED_DEPRECATED(name) void (*name)(Speed)
+
+class HAFan : public BaseDeviceType
+{
+public:
+    static const char* PercentageCommandTopic;
+    static const char* PercentageStateTopic;
+
+    enum Features {
+        DefaultFeatures = 0,
+        SpeedsFeature = 1
+    };
+
+    // @deprecated
+    enum Speed {
+        UnknownSpeed = 0,
+        OffSpeed = 1,
+        LowSpeed = 2,
+        MediumSpeed = 4,
+        HighSpeed = 8
+    };
+
+    HAFan(const char* uniqueId, uint8_t features = DefaultFeatures);
+    HAFan(const char* uniqueId, uint8_t features, HAMqtt& mqtt); // legacy constructor
+
+    virtual void onMqttConnected() override;
+    virtual void onMqttMessage(
+        const char* topic,
+        const uint8_t* payload,
+        const uint16_t& length
+    ) override;
+
+    /**
+     * Changes state of the fan and publishes MQTT message.
+     * Please note that if a new value is the same as previous one,
+     * the MQTT message won't be published.
+     *
+     * @param state New state of the fan (on - true, off - false).
+     * @param force Forces to update state without comparing it to previous known state.
+     * @returns Returns true if MQTT message has been published successfully.
+     */
+    bool setState(bool state, bool force = false);
+
+    /**
+     * Alias for setState(true).
+     */
+    inline bool turnOn()
+        { return setState(true); }
+
+    /**
+     * Alias for setState(false).
+     */
+    inline bool turnOff()
+        { return setState(false); }
+
+    /**
+     * Returns last known state of the fan.
+     * If setState method wasn't called the initial value will be returned.
+     */
+    inline bool getState() const
+        { return _currentState; }
+
+    /**
+     * Registers callback that will be called each time the state of the fan changes.
+     * Please note that it's not possible to register multiple callbacks for the same fan.
+     *
+     * @param callback
+     */
+    inline void onStateChanged(HAFAN_STATE_CALLBACK_BOOL(callback))
+        { _stateCallback = callback; }
+
+    /**
+     * Sets the list of supported fan's speeds.
+     *
+     * @param speeds
+     */
+    AHA_DEPRECATED(inline void setSpeeds(uint8_t speeds))
+        { (void)speeds; }
+
+    /**
+     * Sets speed of the fan.
+     *
+     * @param speed
+     */
+    bool setSpeed(uint16_t speed);
+
+    /**
+     * Returns current speed of the fan.
+     */
+    inline uint16_t getSpeed() const
+        { return _currentSpeed; }
+
+    /**
+     * Registers callback that will be called each time the speed of the fan changes.
+     * Please note that it's not possible to register multiple callbacks for the same fan.
+     *
+     * @param callback
+     */
+    inline void onSpeedChanged(HAFAN_STATE_CALLBACK_SPEED(callback))
+        { _speedCallback = callback; }
+
+    AHA_DEPRECATED(inline void onSpeedChanged(HAFAN_STATE_CALLBACK_SPEED_DEPRECATED(callback)))
+        { (void)callback; }
+
+    /**
+     * Sets `retain` flag for commands published by Home Assistant.
+     * By default it's set to false.
+     *
+     * @param retain
+     */
+    inline void setRetain(bool retain)
+        { _retain = retain; }
+
+    /**
+     * Sets minimum range for slider in the HA panel.
+     *
+     * @param min
+     */
+    inline void setSpeedRangeMin(uint16_t min)
+        { _speedRangeMin = min; }
+
+    /**
+     * Sets maximum range for slider in the HA panel.
+     *
+     * @param min
+     */
+    inline void setSpeedRangeMax(uint16_t max)
+        { _speedRangeMax = max; }
+
+protected:
+    bool publishState(bool state);
+    bool publishSpeed(uint16_t speed);
+    uint16_t calculateSerializedLength(const char* serializedDevice) const override;
+    bool writeSerializedData(const char* serializedDevice) const override;
+
+    const uint8_t _features;
+    bool _currentState;
+    HAFAN_STATE_CALLBACK_BOOL(_stateCallback);
+    uint16_t _currentSpeed;
+    HAFAN_STATE_CALLBACK_SPEED(_speedCallback);
+    bool _retain;
+    uint16_t _speedRangeMin;
+    uint16_t _speedRangeMax;
+};
+
+#endif
+#endif
@@ -0,0 +1,336 @@
+#ifndef AHA_HVAC_H
+#define AHA_HVAC_H
+
+#include "BaseDeviceType.h"
+
+#ifdef ARDUINOHA_HVAC
+
+#define HAHVAC_STATE_CALLBACK_BOOL(name) void (*name)(bool)
+#define HAHVAC_STATE_CALLBACK_DOUBLE(name) void (*name)(double)
+#define HAHVAC_STATE_CALLBACK_MODE(name) void (*name)(HAHVAC::Mode)
+
+class HAHVAC : public BaseDeviceType
+{
+public:
+    static const char* ActionTopic;
+    static const char* AuxCommandTopic;
+    static const char* AuxStateTopic;
+    static const char* AwayCommandTopic;
+    static const char* AwayStateTopic;
+    static const char* HoldCommandTopic;
+    static const char* HoldStateTopic;
+    static const char* TargetTemperatureCommandTopic;
+    static const char* TargetTemperatureStateTopic;
+    static const char* CurrentTemperatureTopic;
+    static const char* ModeCommandTopic;
+    static const char* ModeStateTopic;
+
+    enum Features {
+        DefaultFeatures = 0,
+        ActionFeature = 1,
+        AuxHeatingFeature = 2,
+        AwayModeFeature = 4,
+        HoldFeature = 8
+    };
+
+    enum Action {
+        UnknownAction = 0,
+        OffAction,
+        HeatingAction,
+        CoolingAction,
+        DryingAction,
+        IdleAction,
+        FanAction
+    };
+
+    enum Mode {
+        UnknownMode = 0,
+        OffMode = 1,
+        AutoMode = 2,
+        CoolMode = 4,
+        HeatMode = 8,
+        DryMode = 16,
+        FanOnlyMode = 32
+    };
+
+    enum TemperatureUnit {
+        DefaultUnit = 1,
+        CelsiusUnit,
+        FahrenheitUnit
+    };
+
+    /**
+     * Initializes HVAC.
+     *
+     * @param uniqueId Unique ID of the HVAC. Recommendes characters: [a-z0-9\-_]
+     * @param features The list of additional features (flag). For example: `HAHVAC::AuxHeatingFeature | HAHVAC::AwayModeFeature`
+     */
+    HAHVAC(
+        const char* uniqueId,
+        uint8_t features = 0
+    );
+    HAHVAC(
+        const char* uniqueId,
+        uint8_t features,
+        HAMqtt& mqtt
+    ); // legacy constructor
+
+    virtual void onMqttConnected() override;
+
+    virtual void onMqttMessage(
+        const char* topic,
+        const uint8_t* payload,
+        const uint16_t& length
+    ) override;
+
+    /**
+     * Changes action of the HVAC (it's displayed in the Home Assistant panel).
+     *
+     * @param action New action.
+     * @returns Returns true if MQTT message has been published successfully.
+     */
+    bool setAction(Action action);
+
+    /**
+     * Returns action that was previously sent to MQTT.
+     */
+    inline Action getAction() const
+        { return _action; }
+
+    /**
+     * Changes default temperature unit.
+     * Please note that this method must be called before `mqtt.begin(...)`.
+     *
+     * @param unit See TemperatureUnit enum above
+     */
+    inline void setTemperatureUnit(TemperatureUnit unit)
+        { _temperatureUnit = unit; }
+
+    /**
+     * Publishes aux heating state.
+     * Please note that HAHVAC::AuxHeatingFeature must be set in the constructor.
+     *
+     * @param state ON (true) / OFF (false)
+     * @returns Returns true if MQTT message has been published successfully.
+     */
+    bool setAuxHeatingState(bool state);
+
+    /**
+     * Registers callback that will be called each time the aux heating's state changes.
+     * Please note that it's not possible to register multiple callbacks.
+     *
+     * @param callback
+     */
+    inline void onAuxHeatingStateChanged(HAHVAC_STATE_CALLBACK_BOOL(callback))
+        { _auxHeatingCallback = callback; }
+
+    /**
+     * Returns state of the aux heating.
+     *
+     * @returns ON (true) / OFF (false)
+     */
+    inline bool getAuxHeatingState() const
+        { return _auxHeatingState; }
+
+    /**
+     * Publishes away state.
+     * Please note that HAHVAC::AwayModeFeature must be set in the constructor.
+     *
+     * @param state ON (true) / OFF (false)
+     * @returns Returns true if MQTT message has been published successfully.
+     */
+    bool setAwayState(bool state);
+
+    /**
+     * Registers callback that will be called each time the away's state changes.
+     * Please note that it's not possible to register multiple callbacks.
+     *
+     * @param callback
+     */
+    inline void onAwayStateChanged(HAHVAC_STATE_CALLBACK_BOOL(callback))
+        { _awayCallback = callback; }
+
+    /**
+     * Returns away's state.
+     *
+     * @returns ON (true) / OFF (false)
+     */
+    inline bool getAwayState() const
+        { return _awayState; }
+
+    /**
+     * Publishes hold state.
+     * Please note that HAHVAC::HoldFeature must be set in the constructor.
+     *
+     * @param state ON (true) / OFF (false)
+     * @returns Returns true if MQTT message has been published successfully.
+     */
+    bool setHoldState(bool state);
+
+    /**
+     * Registers callback that will be called each time the hold's state changes.
+     * Please note that it's not possible to register multiple callbacks.
+     *
+     * @param callback
+     */
+    inline void onHoldStateChanged(HAHVAC_STATE_CALLBACK_BOOL(callback))
+        { _holdCallback = callback; }
+
+    /**
+     * Returns hold's state.
+     *
+     * @returns ON (true) / OFF (false)
+     */
+    inline bool getHoldState() const
+        { return _holdState; }
+
+    /**
+     * Publishes given target temperature.
+     *
+     * @param targetTemperature
+     * @returns Returns true if MQTT message has been published successfully.
+     */
+    bool setTargetTemperature(double targetTemperature);
+
+    /**
+     * Registers callback that will be called each time the target temperature changes
+     * Please note that it's not possible to register multiple callbacks.
+     *
+     * @param callback
+     */
+    inline void onTargetTemperatureChanged(HAHVAC_STATE_CALLBACK_DOUBLE(callback))
+        { _targetTempCallback = callback; }
+
+    /**
+     * Returns target temperature.
+     *
+     * @returns Target temperature or __DBL_MAX__ if temperature is not set.
+     */
+    inline double getTargetTemperature() const
+        { return _targetTemperature; }
+
+    /**
+     * Publishes current temperature.
+     *
+     * @param temperature
+     * @returns Returns true if MQTT message has been published successfully.
+     */
+    bool setCurrentTemperature(double temperature);
+
+    /**
+     * Return temperature that was previously set by `setCurrentTemperature` method.
+     *
+     * @returns Temperature or __DBL_MAX__ if temperature is not set.
+     */
+    inline double getCurrentTemperature() const
+        { return _currentTemperature; }
+
+    /**
+     * Publishes working mode of the HVAC.
+     *
+     * @param mode
+     * @returns Returns true if MQTT message has been published successfully.
+     */
+    bool setMode(Mode mode);
+
+    /**
+     * Same as above but input is the string representation of the mode.
+     *
+     * @param mode
+     * @returns Returns true if MQTT message has been published successfully.
+     */
+    bool setModeFromStr(const char* mode);
+
+    /**
+     * Registers callback that will be called each time the mode changes.
+     * Please note that it's not possible to register multiple callbacks.
+     *
+     * @param callback
+     */
+    inline void onModeChanged(HAHVAC_STATE_CALLBACK_MODE(callback))
+        { _modeChangedCallback = callback; }
+
+    /**
+     * Returns HVAC's mode.
+     *
+     * @returns It may be UnknownMode if it's not set.
+     */
+    inline Mode getMode() const
+        { return _currentMode; }
+
+    /**
+     * Sets the list of supported modes. By default the list contains all available modes.
+     * You can merge multiple modes as following: `setModes(HAHVAC::OffMode | HAHVAC::CoolMode)`
+     *
+     * @param modes
+     */
+    inline void setModes(uint8_t modes)
+        { _modes = modes; }
+
+    /**
+     * Sets `retain` flag for commands published by Home Assistant.
+     * By default it's set to false.
+     *
+     * @param retain
+     */
+    inline void setRetain(bool retain)
+        { _retain = retain; }
+
+    /**
+     * Sets the minimum temperature that user will be able to select in Home Assistant panel.
+     *
+     * @param minTemp
+     */
+    bool setMinTemp(double minTemp);
+
+    /**
+     * Sets the maximum temperature that user will be able to select in Home Assistant panel.
+     *
+     * @param minTemp
+     */
+    bool setMaxTemp(double maxTemp);
+
+    /**
+     * Sets the step of the temperature's picker in the Home Assistant panel.
+     *
+     * @param tempStep
+     */
+    bool setTempStep(double tempStep);
+
+private:
+    bool publishAction(Action action);
+    bool publishAuxHeatingState(bool state);
+    bool publishAwayState(bool state);
+    bool publishHoldState(bool state);
+    bool publishCurrentTemperature(double temperature);
+    bool publishTargetTemperature(double temperature);
+    bool publishMode(Mode mode);
+    void subscribeTopics();
+    uint16_t calculateSerializedLength(const char* serializedDevice) const override;
+    uint16_t calculateModesLength() const;
+    bool writeSerializedData(const char* serializedDevice) const override;
+
+    const char* _uniqueId;
+    const uint8_t _features;
+    TemperatureUnit _temperatureUnit;
+    Action _action;
+    HAHVAC_STATE_CALLBACK_BOOL(_auxHeatingCallback);
+    bool _auxHeatingState;
+    HAHVAC_STATE_CALLBACK_BOOL(_awayCallback);
+    bool _awayState;
+    HAHVAC_STATE_CALLBACK_BOOL(_holdCallback);
+    bool _holdState;
+    double _currentTemperature;
+    double _minTemp;
+    double _maxTemp;
+    double _tempStep;
+    HAHVAC_STATE_CALLBACK_DOUBLE(_targetTempCallback);
+    double _targetTemperature;
+    uint8_t _modes;
+    HAHVAC_STATE_CALLBACK_MODE(_modeChangedCallback);
+    Mode _currentMode;
+    bool _retain;
+};
+
+#endif
+#endif
@@ -3,140 +3,92 @@
 #endif

 #include "HASensor.h"
-#include "../ArduinoHADefines.h"
+#ifdef ARDUINOHA_SENSOR
+
 #include "../HAMqtt.h"
 #include "../HADevice.h"
-#include "../HAUtils.h"

-template <typename T>
-HASensor<T>::HASensor(
-    const char* name,
-    T initialValue,
-    HAMqtt& mqtt
-) :
-    BaseDeviceType(mqtt, "sensor", name),
+HASensor::HASensor(const char* uniqueId) :
+    BaseDeviceType("sensor", uniqueId),
    _class(nullptr),
    _units(nullptr),
-    _valueType(HAUtils::determineValueType<T>()),
-    _currentValue(initialValue)
+    _icon(nullptr)
 {

 }

-template <typename T>
-HASensor<T>::HASensor(
-    const char* name,
-    const char* deviceClass,
-    T initialValue,
-    HAMqtt& mqtt
-) :
-    BaseDeviceType(mqtt, "sensor", name),
-    _class(deviceClass),
-    _units(nullptr),
-    _valueType(HAUtils::determineValueType<T>()),
-    _currentValue(initialValue)
+HASensor::HASensor(const char* uniqueId, HAMqtt& mqtt) :
+    HASensor(uniqueId)
 {
-
+    (void)mqtt;
 }

-template <typename T>
-void HASensor<T>::onMqttConnected()
+void HASensor::onMqttConnected()
 {
-    if (strlen(name()) == 0 ||
-            _valueType == HAUtils::ValueTypeUnknown) {
+    if (strlen(uniqueId()) == 0) {
        return;
    }

    publishConfig();
-    publishValue(_currentValue);
    publishAvailability();
 }

-template <typename T>
-bool HASensor<T>::setValue(T value)
+bool HASensor::setValue(const char* value)
 {
-    if (strlen(name()) == 0 ||
-            _valueType == HAUtils::ValueTypeUnknown) {
+    return publishValue(value);
+}
+
+bool HASensor::setValue(uint32_t value)
+{
+    uint8_t digitsNb = floor(log10(value)) + 1;
+    char str[digitsNb + 1]; // + null terminator
+    memset(str, 0, sizeof(str));
+    itoa(value, str, 10);
+
+    return publishValue(str);
+}
+
+bool HASensor::setValue(int32_t value)
+{
+    uint8_t digitsNb = floor(log10(value)) + 1;
+    char str[digitsNb + 2]; // + null terminator and minus sign
+    memset(str, 0, sizeof(str));
+    itoa(value, str, 10);
+
+    return publishValue(str);
+}
+
+bool HASensor::setValue(double value, uint8_t precision)
+{
+    uint8_t digitsNb = floor(log10(floor(value))) + 1;
+    char str[digitsNb + 3 + precision]; // null terminator, dot, minus sign
+    dtostrf(value, 0, precision, str);
+
+    return publishValue(str);
+}
+
+bool HASensor::setValue(float value, uint8_t precision)
+{
+    uint8_t digitsNb = floor(log10(floor(value))) + 1;
+    char str[digitsNb + 3 + precision]; // null terminator, dot, minus sign
+    dtostrf(value, 0, precision, str);
+
+    return publishValue(str);
+}
+
+bool HASensor::publishValue(const char* value)
+{
+    if (strlen(uniqueId()) == 0 || value == nullptr) {
        return false;
    }

-    if (_currentValue == value) {
-        return true;
-    }
-
-    if (publishValue(value)) {
-        _currentValue = value;
-        return true;
-    }
-
-    return false;
-}
-
-template <typename T>
-void HASensor<T>::publishConfig()
-{
-    if (_valueType == HAUtils::ValueTypeUnknown) {
-        return;
-    }
-
-    const HADevice* device = mqtt()->getDevice();
-    if (device == nullptr) {
-        return;
-    }
-
-    const uint16_t& deviceLength = device->calculateSerializedLength();
-    if (deviceLength == 0) {
-        return;
-    }
-
-    char serializedDevice[deviceLength];
-    if (device->serialize(serializedDevice) == 0) {
-        return;
-    }
-
-    const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
-        mqtt(),
-        componentName(),
-        name(),
-        DeviceTypeSerializer::ConfigTopic
-    );
-    const uint16_t& dataLength = calculateSerializedLength(serializedDevice);
-
-    if (topicLength == 0 || dataLength == 0) {
-        return;
-    }
-
-    char topic[topicLength];
-    DeviceTypeSerializer::generateTopic(
-        mqtt(),
-        topic,
-        componentName(),
-        name(),
-        DeviceTypeSerializer::ConfigTopic
-    );
-
-    if (strlen(topic) == 0) {
-        return;
-    }
-
-    if (mqtt()->beginPublish(topic, dataLength, true)) {
-        writeSerializedData(serializedDevice);
-        mqtt()->endPublish();
-    }
-}
-
-template <typename T>
-bool HASensor<T>::publishValue(T value)
-{
-    if (strlen(name()) == 0 ||
-            _valueType == HAUtils::ValueTypeUnknown) {
+    if (!mqtt()->isConnected()) {
        return false;
    }

    const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-        mqtt(),
        componentName(),
-        name(),
+        uniqueId(),
        DeviceTypeSerializer::StateTopic
    );
    if (topicSize == 0) {
@@ -145,10 +97,9 @@ bool HASensor<T>::publishValue(T value)

    char topic[topicSize];
    DeviceTypeSerializer::generateTopic(
-        mqtt(),
        topic,
        componentName(),
-        name(),
+        uniqueId(),
        DeviceTypeSerializer::StateTopic
    );

@@ -156,26 +107,14 @@ bool HASensor<T>::publishValue(T value)
        return false;
    }

-    const uint16_t& valueLength = calculateValueLength();
-    if (valueLength == 0) {
-        return false;
-    }
-
-    char valueStr[valueLength];
-    if (!valueToStr(valueStr, value)) {
-        return false;
-    }
-
-    return mqtt()->publish(topic, valueStr, true);
+    return mqtt()->publish(topic, value, true);
 }

-template <typename T>
-uint16_t HASensor<T>::calculateSerializedLength(
+uint16_t HASensor::calculateSerializedLength(
    const char* serializedDevice
 ) const
 {
-    if (serializedDevice == nullptr ||
-            _valueType == HAUtils::ValueTypeUnknown) {
+    if (serializedDevice == nullptr) {
        return 0;
    }

@@ -186,23 +125,15 @@ uint16_t HASensor<T>::calculateSerializedLength(

    uint16_t size = 0;
    size += DeviceTypeSerializer::calculateBaseJsonDataSize();
-    size += DeviceTypeSerializer::calculateNameFieldSize(name());
-    size += DeviceTypeSerializer::calculateUniqueIdFieldSize(device, name());
+    size += DeviceTypeSerializer::calculateNameFieldSize(getName());
+    size += DeviceTypeSerializer::calculateUniqueIdFieldSize(uniqueId());
    size += DeviceTypeSerializer::calculateDeviceFieldSize(serializedDevice);
-
-    if (isAvailabilityConfigured()) {
-        size += DeviceTypeSerializer::calculateAvailabilityFieldSize(
-            mqtt(),
-            componentName(),
-            name()
-        );
-    }
+    size += DeviceTypeSerializer::calculateAvailabilityFieldSize(this);

    {
        const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-            mqtt(),
            componentName(),
-            name(),
+            uniqueId(),
            DeviceTypeSerializer::StateTopic,
            false
        );
@@ -227,142 +158,61 @@ uint16_t HASensor<T>::calculateSerializedLength(
        size += strlen(_units) + 18; // 18 - length of the JSON decorators for this field
    }

+    // icon
+    if (_icon != nullptr) {
+        // Field format: ,"ic":"[ICON]"
+        size += strlen(_icon) + 8; // 8 - length of the JSON decorators for this field
+    }
+
    return size; // exludes null terminator
 }

-template <typename T>
-bool HASensor<T>::writeSerializedData(const char* serializedDevice) const
+bool HASensor::writeSerializedData(const char* serializedDevice) const
 {
-    if (serializedDevice == nullptr ||
-            _valueType == HAUtils::ValueTypeUnknown) {
+    if (serializedDevice == nullptr) {
        return false;
    }

-    DeviceTypeSerializer::mqttWriteBeginningJson(mqtt());
+    DeviceTypeSerializer::mqttWriteBeginningJson();

    // state topic
    {
-        const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-            mqtt(),
-            componentName(),
-            name(),
-            DeviceTypeSerializer::StateTopic
-        );
-        if (topicSize == 0) {
-            return false;
-        }
-
-        char topic[topicSize];
-        DeviceTypeSerializer::generateTopic(
-            mqtt(),
-            topic,
-            componentName(),
-            name(),
-            DeviceTypeSerializer::StateTopic
-        );
-
-        if (strlen(topic) == 0) {
-            return false;
-        }
-
        static const char Prefix[] PROGMEM = {"\"stat_t\":\""};
-        DeviceTypeSerializer::mqttWriteConstCharField(mqtt(), Prefix, topic);
+        DeviceTypeSerializer::mqttWriteTopicField(
+            this,
+            Prefix,
+            DeviceTypeSerializer::StateTopic
+        );
    }

    // device class
    if (_class != nullptr) {
        static const char Prefix[] PROGMEM = {",\"dev_cla\":\""};
-        DeviceTypeSerializer::mqttWriteConstCharField(mqtt(), Prefix, _class);
+        DeviceTypeSerializer::mqttWriteConstCharField(Prefix, _class);
    }

    // units of measurement
    if (_units != nullptr) {
        static const char Prefix[] PROGMEM = {",\"unit_of_meas\":\""};
-        DeviceTypeSerializer::mqttWriteConstCharField(mqtt(), Prefix, _units);
+        DeviceTypeSerializer::mqttWriteConstCharField(Prefix, _units);
    }

-    DeviceTypeSerializer::mqttWriteNameField(mqtt(), name());
-    DeviceTypeSerializer::mqttWriteUniqueIdField(mqtt(), name());
-
-    if (isAvailabilityConfigured()) {
-        DeviceTypeSerializer::mqttWriteAvailabilityField(
-            mqtt(),
-            componentName(),
-            name()
+    // icon
+    if (_icon != nullptr) {
+        static const char Prefix[] PROGMEM = {",\"ic\":\""};
+        DeviceTypeSerializer::mqttWriteConstCharField(
+            Prefix,
+            _icon
        );
    }

-    DeviceTypeSerializer::mqttWriteDeviceField(mqtt(), serializedDevice);
-    DeviceTypeSerializer::mqttWriteEndJson(mqtt());
+    DeviceTypeSerializer::mqttWriteNameField(getName());
+    DeviceTypeSerializer::mqttWriteUniqueIdField(uniqueId());
+    DeviceTypeSerializer::mqttWriteAvailabilityField(this);
+    DeviceTypeSerializer::mqttWriteDeviceField(serializedDevice);
+    DeviceTypeSerializer::mqttWriteEndJson();

    return true;
 }

-template <typename T>
-uint16_t HASensor<T>::calculateValueLength() const
-{
-    if (_valueType == HAUtils::ValueTypeUnknown) {
-        return 0;
-    }
-
-    uint16_t size = 0;
-
-    switch (_valueType) {
-        case HAUtils::ValueTypeUint8:
-            size = 3; // from 0 to 255
-            break;
-
-        case HAUtils::ValueTypeUint16:
-            size = 5; // from 0 to 65535
-            break;
-
-        case HAUtils::ValueTypeUint32:
-            size = 10; // from 0 to 4294967295
-            break;
-
-        case HAUtils::ValueTypeInt8:
-            size = 4; // from -128 to 127
-            break;
-
-        case HAUtils::ValueTypeInt16:
-            size = 6; // from -32768 to 32767
-            break;
-
-        case HAUtils::ValueTypeInt32:
-            size = 11; // from -2147483648 to 2147483647
-            break;
-
-        case HAUtils::ValueTypeDouble:
-        case HAUtils::ValueTypeFloat:
-            // 3 digits per byte + dot separator + 2 precision digits
-            return (HAUtils::getValueTypeLength(_valueType) * 3) + 3;
-    }
-
-    return (size > 0 ? (size + 1) : 0);
-}
-
-template <typename T>
-bool HASensor<T>::valueToStr(char* dst, T value) const
-{
-    if (_valueType == HAUtils::ValueTypeUnknown) {
-        return false;
-    }
-
-    switch (_valueType) {
-        case HAUtils::ValueTypeUint8:
-        case HAUtils::ValueTypeUint16:
-        case HAUtils::ValueTypeUint32:
-        case HAUtils::ValueTypeInt8:
-        case HAUtils::ValueTypeInt16:
-        case HAUtils::ValueTypeInt32:
-            itoa(value, dst, 10);
-            break;
-
-        case HAUtils::ValueTypeDouble:
-        case HAUtils::ValueTypeFloat:
-            dtostrf(value, 0, 2, dst);
-            break;
-    }
-
-    return true;
-}
+#endif
@@ -2,40 +2,24 @@
 #define AHA_HASENSOR_H

 #include "BaseDeviceType.h"
-#include "../HAUtils.h"

-template <typename T>
+#ifdef ARDUINOHA_SENSOR
+
 class HASensor : public BaseDeviceType
 {
 public:
    /**
     * Initializes binary sensor.
     *
-     * @param name Name of the sensor. Recommendes characters: [a-z0-9\-_]
-     * @param initialValue Initial value of the sensor.
-                           It will be published right after "config" message in order to update HA state.
+     * @param uniqueId Unique ID of the sensor. Recommendes characters: [a-z0-9\-_]
     */
    HASensor(
-        const char* name,
-        T initialValue,
-        HAMqtt& mqtt
+        const char* uniqueId
    );
-
-    /**
-     * Initializes binary sensor with the specified class.
-     * You can find list of available values here: https://www.home-assistant.io/integrations/binary_sensor/#device-class
-     *
-     * @param name Name of the sensor. Recommendes characters: [a-z0-9\-_]
-     * @param deviceClass Name of the class (lower case).
-     * @param initialValue Initial value of the sensor.
-                           It will be published right after "config" message in order to update HA state.
-     */
    HASensor(
-        const char* name,
-        const char* deviceClass,
-        T initialValue,
+        const char* uniqueId,
        HAMqtt& mqtt
-    );
+    ); // legacy constructor

    /**
     * Publishes configuration of the sensor to the MQTT.
@@ -43,21 +27,38 @@ public:
    virtual void onMqttConnected() override;

    /**
-     * Changes state of the sensor and publishes MQTT message.
-     * Please note that if a new value is the same as previous one,
-     * the MQTT message won't be published.
+     * Publishes new value of the sensor.
+     * Please note that connection to MQTT broker must be acquired.
+     * Otherwise method will return false.
     *
-     * @param state New state of the sensor.
+     * @param state Value to publish.
     * @returns Returns true if MQTT message has been published successfully.
     */
-    bool setValue(T value);
+    bool setValue(const char* value);
+    bool setValue(uint32_t value);
+    bool setValue(int32_t value);
+    bool setValue(double value, uint8_t precision = 2);
+    bool setValue(float value, uint8_t precision = 2);
+
+    inline bool setValue(uint8_t value)
+        { return setValue(static_cast<uint32_t>(value)); }
+
+    inline bool setValue(uint16_t value)
+        { return setValue(static_cast<uint32_t>(value)); }
+
+    inline bool setValue(int8_t value)
+        { return setValue(static_cast<int32_t>(value)); }
+
+    inline bool setValue(int16_t value)
+        { return setValue(static_cast<int32_t>(value)); }

    /**
-     * Returns last known state of the sensor.
-     * If setState method wasn't called the initial value will be returned.
+     * The type/class of the sensor to set the icon in the frontend.
+     *
+     * @param className https://www.home-assistant.io/integrations/sensor/#device-class
     */
-    inline T getValue() const
-        { return _currentValue; }
+    inline void setDeviceClass(const char* className)
+        { _class = className; }

    /**
     * Defines the units of measurement of the sensor, if any.
@@ -67,18 +68,23 @@ public:
    inline void setUnitOfMeasurement(const char* units)
        { _units = units; }

+    /**
+     * Sets icon of the sensor, e.g. `mdi:home`.
+     *
+     * @param icon Material Design Icon name with mdi: prefix.
+     */
+    inline void setIcon(const char* icon)
+        { _icon = icon; }
+
 private:
-    void publishConfig();
-    bool publishValue(T value);
-    uint16_t calculateSerializedLength(const char* serializedDevice) const;
-    bool writeSerializedData(const char* serializedDevice) const;
-    uint16_t calculateValueLength() const;
-    bool valueToStr(char* dst, T value) const;
+    bool publishValue(const char* value);
+    uint16_t calculateSerializedLength(const char* serializedDevice) const override;
+    bool writeSerializedData(const char* serializedDevice) const override;

    const char* _class;
    const char* _units;
-    HAUtils::ValueType _valueType;
-    T _currentValue;
+    const char* _icon;
 };

 #endif
+#endif
@@ -1,27 +1,48 @@
 #include "HASwitch.h"
+#ifdef ARDUINOHA_SWITCH
+
 #include "../ArduinoHADefines.h"
 #include "../HAMqtt.h"
 #include "../HADevice.h"
-#include "../HAUtils.h"

-HASwitch::HASwitch(const char* name, bool initialState, HAMqtt& mqtt) :
-    BaseDeviceType(mqtt, "switch", name),
+HASwitch::HASwitch(const char* uniqueId, bool initialState) :
+    BaseDeviceType("switch", uniqueId),
    _stateCallback(nullptr),
-    _currentState(initialState)
+    _beforeStateCallback(nullptr),
+    _currentState(initialState),
+    _icon(nullptr),
+    _retain(false)
 {

 }

+HASwitch::HASwitch(
+    const char* uniqueId,
+    bool initialState,
+    HAMqtt& mqtt
+) :
+    HASwitch(uniqueId, initialState)
+{
+    (void)mqtt;
+}
+
 void HASwitch::onMqttConnected()
 {
-    if (strlen(name()) == 0) {
+    if (strlen(uniqueId()) == 0) {
        return;
    }

    publishConfig();
-    publishState(_currentState);
-    subscribeCommandTopic();
    publishAvailability();
+
+    if (!_retain) {
+        publishState(_currentState);
+    }
+
+    DeviceTypeSerializer::mqttSubscribeTopic(
+        this,
+        DeviceTypeSerializer::CommandTopic
+    );
 }

 void HASwitch::onMqttMessage(
@@ -30,170 +51,54 @@ void HASwitch::onMqttMessage(
    const uint16_t& length
 )
 {
-    if (strlen(name()) == 0) {
-        return;
-    }
+    (void)payload;

-    static const char Slash[] PROGMEM = {"/"};
-    // name + cmd topic + two slashes + null terminator
-    uint8_t suffixLength = strlen(name()) + strlen(DeviceTypeSerializer::CommandTopic) + 3;
-    char suffix[suffixLength];
-
-    strcpy_P(suffix, Slash);
-    strcat(suffix, name());
-    strcat_P(suffix, Slash);
-    strcat(suffix, DeviceTypeSerializer::CommandTopic);
-
-    if (HAUtils::endsWith(topic, suffix)) {
-        bool onState = (length == strlen(DeviceTypeSerializer::StateOn));
-        setState(onState);
+    if (compareTopics(topic, DeviceTypeSerializer::CommandTopic)) {
+        bool state = (length == strlen(DeviceTypeSerializer::StateOn));
+        setState(state, true);
    }
 }

-bool HASwitch::setState(bool state)
+bool HASwitch::setState(bool state, bool force)
 {
-    if (_currentState == state) {
+    if (!force && _currentState == state) {
        return true;
    }

-    if (strlen(name()) == 0) {
-        return false;
+    if (_beforeStateCallback) {
+        _beforeStateCallback(state, this);
    }

    if (publishState(state)) {
        _currentState = state;
-        triggerCallback(_currentState);
+
+        if (_stateCallback) {
+            _stateCallback(_currentState, this);
+        }
+
        return true;
    }

    return false;
 }

-void HASwitch::triggerCallback(bool state)
-{
-    if (_stateCallback == nullptr) {
-        return;
-    }
-
-    _stateCallback(state, this);
-}
-
-void HASwitch::publishConfig()
-{
-    const HADevice* device = mqtt()->getDevice();
-    if (device == nullptr) {
-        return;
-    }
-
-    const uint16_t& deviceLength = device->calculateSerializedLength();
-    if (deviceLength == 0) {
-        return;
-    }
-
-    char serializedDevice[deviceLength];
-    if (device->serialize(serializedDevice) == 0) {
-        return;
-    }
-
-    const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
-        mqtt(),
-        componentName(),
-        name(),
-        DeviceTypeSerializer::ConfigTopic
-    );
-    const uint16_t& dataLength = calculateSerializedLength(serializedDevice);
-
-    if (topicLength == 0 || dataLength == 0) {
-        return;
-    }
-
-    char topic[topicLength];
-    DeviceTypeSerializer::generateTopic(
-        mqtt(),
-        topic,
-        componentName(),
-        name(),
-        DeviceTypeSerializer::ConfigTopic
-    );
-
-    if (strlen(topic) == 0) {
-        return;
-    }
-
-    if (mqtt()->beginPublish(topic, dataLength, true)) {
-        writeSerializedData(serializedDevice);
-        mqtt()->endPublish();
-    }
-}
-
 bool HASwitch::publishState(bool state)
 {
-    if (strlen(name()) == 0) {
+    if (strlen(uniqueId()) == 0) {
        return false;
    }

-    const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-        mqtt(),
-        componentName(),
-        name(),
-        DeviceTypeSerializer::StateTopic
-    );
-    if (topicSize == 0) {
-        return false;
-    }
-
-    char topic[topicSize];
-    DeviceTypeSerializer::generateTopic(
-        mqtt(),
-        topic,
-        componentName(),
-        name(),
-        DeviceTypeSerializer::StateTopic
-    );
-
-    if (strlen(topic) == 0) {
-        return false;
-    }
-
-    return mqtt()->publish(
-        topic,
+    return DeviceTypeSerializer::mqttPublishMessage(
+        this,
+        DeviceTypeSerializer::StateTopic,
        (
            state ?
            DeviceTypeSerializer::StateOn :
            DeviceTypeSerializer::StateOff
-        ),
-        true
+        )
    );
 }

-void HASwitch::subscribeCommandTopic()
-{
-    const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-        mqtt(),
-        componentName(),
-        name(),
-        DeviceTypeSerializer::CommandTopic
-    );
-    if (topicSize == 0) {
-        return;
-    }
-
-    char topic[topicSize];
-    DeviceTypeSerializer::generateTopic(
-        mqtt(),
-        topic,
-        componentName(),
-        name(),
-        DeviceTypeSerializer::CommandTopic
-    );
-
-    if (strlen(topic) == 0) {
-        return;
-    }
-
-    mqtt()->subscribe(topic);
-}
-
 uint16_t HASwitch::calculateSerializedLength(const char* serializedDevice) const
 {
    if (serializedDevice == nullptr) {
@@ -207,24 +112,17 @@ uint16_t HASwitch::calculateSerializedLength(const char* serializedDevice) const

    uint16_t size = 0;
    size += DeviceTypeSerializer::calculateBaseJsonDataSize();
-    size += DeviceTypeSerializer::calculateNameFieldSize(name());
-    size += DeviceTypeSerializer::calculateUniqueIdFieldSize(device, name());
+    size += DeviceTypeSerializer::calculateNameFieldSize(getName());
+    size += DeviceTypeSerializer::calculateUniqueIdFieldSize(uniqueId());
    size += DeviceTypeSerializer::calculateDeviceFieldSize(serializedDevice);
-
-    if (isAvailabilityConfigured()) {
-        size += DeviceTypeSerializer::calculateAvailabilityFieldSize(
-            mqtt(),
-            componentName(),
-            name()
-        );
-    }
+    size += DeviceTypeSerializer::calculateAvailabilityFieldSize(this);
+    size += DeviceTypeSerializer::calculateRetainFieldSize(_retain);

    // cmd topic
    {
        const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
-            mqtt(),
            componentName(),
-            name(),
+            uniqueId(),
            DeviceTypeSerializer::CommandTopic,
            false
        );
@@ -240,9 +138,8 @@ uint16_t HASwitch::calculateSerializedLength(const char* serializedDevice) const
    // state topic
    {
        const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
-            mqtt(),
            componentName(),
-            name(),
+            uniqueId(),
            DeviceTypeSerializer::StateTopic,
            false
        );
@@ -255,6 +152,12 @@ uint16_t HASwitch::calculateSerializedLength(const char* serializedDevice) const
        size += topicLength + 12; // 12 - length of the JSON decorators for this field
    }

+    // icon
+    if (_icon != nullptr) {
+        // Field format: ,"ic":"[ICON]"
+        size += strlen(_icon) + 8; // 8 - length of the JSON decorators for this field
+    }
+
    return size; // exludes null terminator
 }

@@ -264,79 +167,45 @@ bool HASwitch::writeSerializedData(const char* serializedDevice) const
        return false;
    }

-    DeviceTypeSerializer::mqttWriteBeginningJson(mqtt());
+    DeviceTypeSerializer::mqttWriteBeginningJson();

    // command topic
    {
-        const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-            mqtt(),
-            componentName(),
-            name(),
-            DeviceTypeSerializer::CommandTopic
-        );
-        if (topicSize == 0) {
-            return false;
-        }
-
-        char topic[topicSize];
-        DeviceTypeSerializer::generateTopic(
-            mqtt(),
-            topic,
-            componentName(),
-            name(),
-            DeviceTypeSerializer::CommandTopic
-        );
-
-        if (strlen(topic) == 0) {
-            return false;
-        }
-
        static const char Prefix[] PROGMEM = {"\"cmd_t\":\""};
-        DeviceTypeSerializer::mqttWriteConstCharField(mqtt(), Prefix, topic);
+        DeviceTypeSerializer::mqttWriteTopicField(
+            this,
+            Prefix,
+            DeviceTypeSerializer::CommandTopic
+        );
    }

    // state topic
    {
-        const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-            mqtt(),
-            componentName(),
-            name(),
-            DeviceTypeSerializer::StateTopic
-        );
-        if (topicSize == 0) {
-            return false;
-        }
-
-        char topic[topicSize];
-        DeviceTypeSerializer::generateTopic(
-            mqtt(),
-            topic,
-            componentName(),
-            name(),
-            DeviceTypeSerializer::StateTopic
-        );
-
-        if (strlen(topic) == 0) {
-            return false;
-        }
-
        static const char Prefix[] PROGMEM = {",\"stat_t\":\""};
-        DeviceTypeSerializer::mqttWriteConstCharField(mqtt(), Prefix, topic);
-    }
-
-    DeviceTypeSerializer::mqttWriteNameField(mqtt(), name());
-    DeviceTypeSerializer::mqttWriteUniqueIdField(mqtt(), name());
-
-    if (isAvailabilityConfigured()) {
-        DeviceTypeSerializer::mqttWriteAvailabilityField(
-            mqtt(),
-            componentName(),
-            name()
+        DeviceTypeSerializer::mqttWriteTopicField(
+            this,
+            Prefix,
+            DeviceTypeSerializer::StateTopic
        );
    }

-    DeviceTypeSerializer::mqttWriteDeviceField(mqtt(), serializedDevice);
-    DeviceTypeSerializer::mqttWriteEndJson(mqtt());
+    // icon
+    if (_icon != nullptr) {
+        static const char Prefix[] PROGMEM = {",\"ic\":\""};
+        DeviceTypeSerializer::mqttWriteConstCharField(
+            Prefix,
+            _icon
+        );
+    }
+
+    DeviceTypeSerializer::mqttWriteRetainField(_retain);
+    DeviceTypeSerializer::mqttWriteNameField(getName());
+    DeviceTypeSerializer::mqttWriteUniqueIdField(uniqueId());
+    DeviceTypeSerializer::mqttWriteAvailabilityField(this);
+    DeviceTypeSerializer::mqttWriteDeviceField(serializedDevice);
+    DeviceTypeSerializer::mqttWriteEndJson();

    return true;
 }
+
+#endif
@@ -3,7 +3,9 @@

 #include "BaseDeviceType.h"

-#define HASWITCH_CALLBACK void (*callback)(bool, HASwitch*)
+#ifdef ARDUINOHA_SWITCH
+
+#define HASWITCH_CALLBACK(name) void (*name)(bool, HASwitch*)

 class HASwitch : public BaseDeviceType
 {
@@ -11,15 +13,19 @@ public:
    /**
     * Initializes switch.
     *
-     * @param name Name of the switch. Recommendes characters: [a-z0-9\-_]
+     * @param uniqueId Unique ID of the switch. Recommendes characters: [a-z0-9\-_]
     * @param initialState Initial state of the switch.
                           It will be published right after "config" message in order to update HA state.
     */
    HASwitch(
-        const char* name,
+        const char* uniqueId,
+        bool initialState
+    );
+    HASwitch(
+        const char* uniqueId,
        bool initialState,
        HAMqtt& mqtt
-    );
+    ); // legacy constructor

    /**
     * Publishes configuration of the sensor to the MQTT.
@@ -36,21 +42,16 @@ public:
        const uint16_t& length
    ) override;

-    /**
-     * Returns name of the switch assigned via constructor.
-     */
-    inline const char* getName() const
-        { return _name; }
-
    /**
     * Changes state of the switch and publishes MQTT message.
     * Please note that if a new value is the same as previous one,
     * the MQTT message won't be published.
     *
     * @param state New state of the switch.
+     * @param force Forces to update state without comparing it to previous known state.
     * @returns Returns true if MQTT message has been published successfully.
     */
-    bool setState(bool state);
+    bool setState(bool state, bool force = false);

    /**
     * Alias for setState(true).
@@ -72,24 +73,51 @@ public:
        { return _currentState; }

    /**
-     * Registers callback that will be called each time the value of the switch changes.
+     * Registers callback that will be called each time the state of the switch changes.
     * Please note that it's not possible to register multiple callbacks for the same switch.
     *
     * @param callback
     */
-    inline void onStateChanged(HASWITCH_CALLBACK)
+    inline void onStateChanged(HASWITCH_CALLBACK(callback))
        { _stateCallback = callback; }

-private:
-    void triggerCallback(bool state);
-    void publishConfig();
-    bool publishState(bool state);
-    void subscribeCommandTopic();
-    uint16_t calculateSerializedLength(const char* serializedDevice) const;
-    bool writeSerializedData(const char* serializedDevice) const;
+    /**
+     * Registers callback that will be called before state of the switch changes.
+     * The state passed to callback is a new state that is going to be set.
+     *
+     * @param callback
+     */
+    inline void onBeforeStateChanged(HASWITCH_CALLBACK(callback))
+        { _beforeStateCallback = callback; }

-    void (*_stateCallback)(bool, HASwitch*);
+    /**
+     * Sets icon of the switch, e.g. `mdi:home`.
+     *
+     * @param icon Material Design Icon name with mdi: prefix.
+     */
+    inline void setIcon(const char* icon)
+        { _icon = icon; }
+
+    /**
+     * Sets `retain` flag for commands published by Home Assistant.
+     * By default it's set to false.
+     *
+     * @param retain
+     */
+    inline void setRetain(bool retain)
+        { _retain = retain; }
+
+private:
+    bool publishState(bool state);
+    uint16_t calculateSerializedLength(const char* serializedDevice) const override;
+    bool writeSerializedData(const char* serializedDevice) const override;
+
+    HASWITCH_CALLBACK(_stateCallback);
+    HASWITCH_CALLBACK(_beforeStateCallback);
    bool _currentState;
+    const char* _icon;
+    bool _retain;
 };

 #endif
+#endif
@@ -1,18 +1,25 @@
 #include "HATagScanner.h"
+#ifdef ARDUINOHA_TAG_SCANNER
+
 #include "../ArduinoHADefines.h"
 #include "../HAMqtt.h"
 #include "../HADevice.h"
-#include "../HAUtils.h"

-HATagScanner::HATagScanner(const char* name, HAMqtt& mqtt) :
-    BaseDeviceType(mqtt, "tag", name)
+HATagScanner::HATagScanner(const char* uniqueId) :
+    BaseDeviceType("tag", uniqueId)
 {

 }

+HATagScanner::HATagScanner(const char* uniqueId, HAMqtt& mqtt) :
+    HATagScanner(uniqueId)
+{
+    (void)mqtt;
+}
+
 void HATagScanner::onMqttConnected()
 {
-    if (strlen(name()) == 0) {
+    if (strlen(uniqueId()) == 0) {
        return;
    }

@@ -21,14 +28,13 @@ void HATagScanner::onMqttConnected()

 bool HATagScanner::tagScanned(const char* tag)
 {
-    if (tag == nullptr || strlen(tag) == 0) {
+    if (tag == nullptr || strlen(tag) == 0 || strlen(uniqueId()) == 0) {
        return false;
    }

    const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-        mqtt(),
        componentName(),
-        name(),
+        uniqueId(),
        DeviceTypeSerializer::EventTopic
    );
    if (topicSize == 0) {
@@ -37,10 +43,9 @@ bool HATagScanner::tagScanned(const char* tag)

    char topic[topicSize];
    DeviceTypeSerializer::generateTopic(
-        mqtt(),
        topic,
        componentName(),
-        name(),
+        uniqueId(),
        DeviceTypeSerializer::EventTopic
    );

@@ -51,54 +56,6 @@ bool HATagScanner::tagScanned(const char* tag)
    return mqtt()->publish(topic, tag);
 }

-void HATagScanner::publishConfig()
-{
-    const HADevice* device = mqtt()->getDevice();
-    if (device == nullptr) {
-        return;
-    }
-
-    const uint16_t& deviceLength = device->calculateSerializedLength();
-    if (deviceLength == 0) {
-        return;
-    }
-
-    char serializedDevice[deviceLength];
-    if (device->serialize(serializedDevice) == 0) {
-        return;
-    }
-
-    const uint16_t& topicLength = DeviceTypeSerializer::calculateTopicLength(
-        mqtt(),
-        componentName(),
-        name(),
-        DeviceTypeSerializer::ConfigTopic
-    );
-    const uint16_t& dataLength = calculateSerializedLength(serializedDevice);
-
-    if (topicLength == 0 || dataLength == 0) {
-        return;
-    }
-
-    char topic[topicLength];
-    DeviceTypeSerializer::generateTopic(
-        mqtt(),
-        topic,
-        componentName(),
-        name(),
-        DeviceTypeSerializer::ConfigTopic
-    );
-
-    if (strlen(topic) == 0) {
-        return;
-    }
-
-    if (mqtt()->beginPublish(topic, dataLength, true)) {
-        writeSerializedData(serializedDevice);
-        mqtt()->endPublish();
-    }
-}
-
 uint16_t HATagScanner::calculateSerializedLength(
    const char* serializedDevice
 ) const
@@ -114,9 +71,8 @@ uint16_t HATagScanner::calculateSerializedLength(
    // event topic
    {
        const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-            mqtt(),
            componentName(),
-            name(),
+            uniqueId(),
            DeviceTypeSerializer::EventTopic,
            false
        );
@@ -134,31 +90,22 @@ bool HATagScanner::writeSerializedData(const char* serializedDevice) const
        return false;
    }

-    DeviceTypeSerializer::mqttWriteBeginningJson(mqtt());
+    DeviceTypeSerializer::mqttWriteBeginningJson();

    // topic
    {
-        const uint16_t& topicSize = DeviceTypeSerializer::calculateTopicLength(
-            mqtt(),
-            componentName(),
-            name(),
-            DeviceTypeSerializer::EventTopic
-        );
-        char topic[topicSize];
-        DeviceTypeSerializer::generateTopic(
-            mqtt(),
-            topic,
-            componentName(),
-            name(),
-            DeviceTypeSerializer::EventTopic
-        );
-
        static const char Prefix[] PROGMEM = {"\"t\":\""};
-        DeviceTypeSerializer::mqttWriteConstCharField(mqtt(), Prefix, topic);
+        DeviceTypeSerializer::mqttWriteTopicField(
+            this,
+            Prefix,
+            DeviceTypeSerializer::EventTopic
+        );
    }

-    DeviceTypeSerializer::mqttWriteDeviceField(mqtt(), serializedDevice);
-    DeviceTypeSerializer::mqttWriteEndJson(mqtt());
+    DeviceTypeSerializer::mqttWriteDeviceField(serializedDevice);
+    DeviceTypeSerializer::mqttWriteEndJson();

    return true;
 }
+
+#endif
@@ -3,15 +3,18 @@

 #include "BaseDeviceType.h"

+#ifdef ARDUINOHA_TAG_SCANNER
+
 class HATagScanner : public BaseDeviceType
 {
 public:
    /**
     * Initializes tag scanner with the given name.
     *
-     * @param name Name of the scanner. Recommendes characters: [a-z0-9\-_]
+     * @param uniqueId Unique ID of the scanner. Recommendes characters: [a-z0-9\-_]
     */
-    HATagScanner(const char* name, HAMqtt& mqtt);
+    HATagScanner(const char* uniqueId);
+    HATagScanner(const char* uniqueId, HAMqtt& mqtt); // legacy constructor

    /**
     * Publishes configuration of the sensor to the MQTT.
@@ -21,7 +24,7 @@ public:
    /**
     * Tag scanner doesn't support availability. Nothing to do here.
     */
-    virtual void setAvailability(bool online) override { }
+    virtual void setAvailability(bool online) override { (void)online; }

    /**
     * Sends "tag scanned" event to the MQTT (Home Assistant).
@@ -32,9 +35,9 @@ public:
    bool tagScanned(const char* tag);

 private:
-    void publishConfig();
-    uint16_t calculateSerializedLength(const char* serializedDevice) const;
-    bool writeSerializedData(const char* serializedDevice) const;
+    uint16_t calculateSerializedLength(const char* serializedDevice) const override;
+    bool writeSerializedData(const char* serializedDevice) const override;
 };

 #endif
+#endif
@@ -1,16 +1,24 @@
 #include "HATriggers.h"
+#ifdef ARDUINOHA_TRIGGERS
+
 #include "../ArduinoHADefines.h"
 #include "../HAMqtt.h"
 #include "../HADevice.h"

-HATriggers::HATriggers(HAMqtt& mqtt) :
-    BaseDeviceType(mqtt, "device_automation", nullptr),
+HATriggers::HATriggers() :
+    BaseDeviceType("device_automation", nullptr),
    _triggers(nullptr),
    _triggersNb(0)
 {

 }

+HATriggers::HATriggers(HAMqtt& mqtt) :
+    HATriggers()
+{
+    (void)mqtt;
+}
+
 HATriggers::~HATriggers()
 {
    if (_triggers != nullptr) {
@@ -87,6 +95,14 @@ bool HATriggers::trigger(const char* type, const char* subtype)
        return false;
    }

+#if defined(ARDUINOHA_DEBUG)
+    Serial.print(F("Triggering HATrigger: "));
+    Serial.print(type);
+    Serial.print(F(" "));
+    Serial.print(subtype);
+    Serial.println();
+#endif
+
    return mqtt()->publish(topic, "");
 }

@@ -116,13 +132,14 @@ void HATriggers::publishConfig()
        const uint16_t& topicLength = calculateTopicLength(
            componentName(),
            trigger,
-            DeviceTypeSerializer::ConfigTopic
+            DeviceTypeSerializer::ConfigTopic,
+            true,
+            true
        );
        const uint16_t& dataLength = calculateSerializedLength(
            trigger,
            serializedDevice
        );
-
        if (topicLength == 0 || dataLength == 0) {
            continue;
        }
@@ -132,7 +149,8 @@ void HATriggers::publishConfig()
            topic,
            componentName(),
            trigger,
-            DeviceTypeSerializer::ConfigTopic
+            DeviceTypeSerializer::ConfigTopic,
+            true
        );

        if (strlen(topic) == 0) {
@@ -150,16 +168,17 @@ uint16_t HATriggers::calculateTopicLength(
    const char* component,
    const HATrigger *trigger,
    const char* suffix,
-    bool includeNullTerminator
+    bool includeNullTerminator,
+    bool isDiscoveryTopic
 ) const
 {
-    uint8_t length = strlen(trigger->type) + strlen(trigger->subtype) + 1; // + underscore
+    uint8_t length = strlen(trigger->type) + strlen(trigger->subtype) + 2; // underscore and slash
    return DeviceTypeSerializer::calculateTopicLength(
-        mqtt(),
        component,
        nullptr,
        suffix,
-        includeNullTerminator
+        includeNullTerminator,
+        isDiscoveryTopic
    ) + length;
 }

@@ -167,11 +186,12 @@ uint16_t HATriggers::generateTopic(
    char* output,
    const char* component,
    const HATrigger *trigger,
-    const char* suffix
+    const char* suffix,
+    bool isDiscoveryTopic
 ) const
 {
    static const char Underscore[] PROGMEM = {"_"};
-    uint8_t length = strlen(trigger->type) + strlen(trigger->subtype) + 2; // slash + null terminator
+    uint8_t length = strlen(trigger->type) + strlen(trigger->subtype) + 2; // underscore + null terminator
    char objectId[length];

    strcpy(objectId, trigger->subtype);
@@ -179,11 +199,11 @@ uint16_t HATriggers::generateTopic(
    strcat(objectId, trigger->type);

    return DeviceTypeSerializer::generateTopic(
-        mqtt(),
        output,
        component,
        objectId,
-        suffix
+        suffix,
+        isDiscoveryTopic
    );
 }

@@ -246,7 +266,7 @@ bool HATriggers::writeSerializedTrigger(
        return false;
    }

-    DeviceTypeSerializer::mqttWriteBeginningJson(mqtt());
+    DeviceTypeSerializer::mqttWriteBeginningJson();

    // automation type
    {
@@ -273,28 +293,29 @@ bool HATriggers::writeSerializedTrigger(
            DeviceTypeSerializer::EventTopic
        );

-        if (strlen(topic) == 0) {
-            return false;
-        }
-
        static const char Prefix[] PROGMEM = {",\"t\":\""};
-        DeviceTypeSerializer::mqttWriteConstCharField(mqtt(), Prefix, topic);
+        DeviceTypeSerializer::mqttWriteConstCharField(
+            Prefix,
+            topic
+        );
    }

    // type
    {
        static const char Prefix[] PROGMEM = {",\"type\":\""};
-        DeviceTypeSerializer::mqttWriteConstCharField(mqtt(), Prefix, trigger->type);
+        DeviceTypeSerializer::mqttWriteConstCharField(Prefix, trigger->type);
    }

    // subtype
    {
        static const char Prefix[] PROGMEM = {",\"stype\":\""};
-        DeviceTypeSerializer::mqttWriteConstCharField(mqtt(), Prefix, trigger->subtype);
+        DeviceTypeSerializer::mqttWriteConstCharField(Prefix, trigger->subtype);
    }

-    DeviceTypeSerializer::mqttWriteDeviceField(mqtt(), serializedDevice);
-    DeviceTypeSerializer::mqttWriteEndJson(mqtt());
+    DeviceTypeSerializer::mqttWriteDeviceField(serializedDevice);
+    DeviceTypeSerializer::mqttWriteEndJson();

    return true;
 }
+
+#endif
@@ -3,6 +3,8 @@

 #include "BaseDeviceType.h"

+#ifdef ARDUINOHA_TRIGGERS
+
 struct HATrigger {
    const char* type;
    const char* subtype;
@@ -11,7 +13,8 @@ struct HATrigger {
 class HATriggers : public BaseDeviceType
 {
 public:
-    HATriggers(HAMqtt& mqtt);
+    HATriggers();
+    HATriggers(HAMqtt& mqtt); // legacy constructor
    virtual ~HATriggers();

    virtual void onMqttConnected() override;
@@ -19,29 +22,39 @@ public:
    /**
     * Triggers dont't support availability. Nothing to do here.
     */
-    virtual void setAvailability(bool online) override { }
+    virtual void setAvailability(bool online) override { (void)online; }

    bool add(const char* type, const char* subtype);
    bool trigger(const char* type, const char* subtype);

 protected:
+    void publishConfig() override;
+
+    uint16_t calculateSerializedLength(
+        const char* serializedDevice
+    ) const override { (void)serializedDevice; return 0; }
+
+    bool writeSerializedData(
+        const char* serializedDevice
+    ) const override { (void)serializedDevice; return false; }
+
    uint16_t calculateTopicLength(
        const char* component,
        const HATrigger *trigger,
        const char* suffix,
-        bool includeNullTerminator = true
+        bool includeNullTerminator = true,
+        bool isDiscoveryTopic = false
    ) const;

    uint16_t generateTopic(
        char* output,
        const char* component,
        const HATrigger *trigger,
-        const char* suffix
+        const char* suffix,
+        bool isDiscoveryTopic = false
    ) const;

 private:
-    void publishConfig();
-
    uint16_t calculateSerializedLength(
        const HATrigger* trigger,
        const char* serializedDevice
@@ -57,3 +70,4 @@ private:
 };

 #endif
+#endif