diff --git a/.gitignore b/.gitignore
index 89cc49c..d3a58ed 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@
 .vscode/c_cpp_properties.json
 .vscode/launch.json
 .vscode/ipch
+data/homie/config.json
diff --git a/lib/HomieNodes/DHT22Node.cpp b/lib/HomieNodes/DHT22Node.cpp
new file mode 100644
index 0000000..15989e0
--- /dev/null
+++ b/lib/HomieNodes/DHT22Node.cpp
@@ -0,0 +1,105 @@
+/*
+ * DHT22Node.cpp
+ * Homie Node for DHT22 sensors using Adafruit DHT22 library.
+ *
+ * Version: 1.0
+ * Author: Lübbe Onken (http://github.com/luebbe)
+ */
+
+#include "DHT22Node.hpp"
+
+#define DHTTYPE DHT22
+
+DHT22Node::DHT22Node(const char *name, const int sensorPin, const int measurementInterval)
+    : SensorNode(name, "DHT22"),
+      _sensorPin(sensorPin),
+      _measurementInterval(measurementInterval),
+      _lastMeasurement(0)
+{
+  if (_sensorPin > DEFAULTPIN)
+  {
+    dht = new DHT(_sensorPin, DHTTYPE);
+  }
+
+  advertise(cStatusTopic)
+      .setDatatype("enum")
+      .setFormat("error, ok");
+  advertise(cTemperatureTopic)
+      .setDatatype("float")
+      .setFormat("-40:125")
+      .setUnit(cUnitDegrees);
+  advertise(cHumidityTopic)
+      .setDatatype("float")
+      .setFormat("0:100")
+      .setUnit(cUnitPercent);
+  advertise(cAbsHumidityTopic)
+      .setDatatype("float")
+      .setUnit(cUnitMgm3);
+}
+
+void DHT22Node::printCaption()
+{
+  Homie.getLogger() << cCaption << " pin[" << _sensorPin << "]:" << endl;
+}
+
+void DHT22Node::send()
+{
+  printCaption();
+
+  if (isnan(temperature) || isnan(humidity))
+  {
+    Homie.getLogger() << cIndent << "Error reading from Sensor" << endl;
+
+    if (Homie.isConnected())
+    {
+      setProperty(cStatusTopic).send("error");
+    }
+  }
+  else
+  {
+    float absHumidity = computeAbsoluteHumidity(temperature, humidity);
+
+    Homie.getLogger() << cIndent << "Temperature: " << temperature << " °C" << endl;
+    Homie.getLogger() << cIndent << "Humidity: " << humidity << " %" << endl;
+    Homie.getLogger() << cIndent << "Abs humidity: " << absHumidity << " g/m³" << endl;
+
+    if (Homie.isConnected())
+    {
+      setProperty(cStatusTopic).send("ok");
+      setProperty(cTemperatureTopic).send(String(temperature));
+      setProperty(cHumidityTopic).send(String(humidity));
+      setProperty(cAbsHumidityTopic).send(String(absHumidity));
+    }
+  }
+}
+
+void DHT22Node::loop()
+{
+  if (dht)
+  {
+    if ((millis() - _lastMeasurement >= _measurementInterval * 1000UL) ||
+        (_lastMeasurement == 0))
+    {
+      temperature = dht->readTemperature();
+      humidity = dht->readHumidity();
+
+      fixRange(&temperature, cMinTemp, cMaxTemp);
+      fixRange(&humidity, cMinHumid, cMaxHumid);
+
+      send();
+
+      _lastMeasurement = millis();
+    }
+  }
+}
+
+void DHT22Node::setup()
+{
+  printCaption();
+  Homie.getLogger() << cIndent << "Reading interval: " << _measurementInterval << " s" << endl;
+
+  if (dht)
+  {
+    dht->begin();
+  }
+}
diff --git a/lib/HomieNodes/DHT22Node.hpp b/lib/HomieNodes/DHT22Node.hpp
new file mode 100644
index 0000000..cc46def
--- /dev/null
+++ b/lib/HomieNodes/DHT22Node.hpp
@@ -0,0 +1,50 @@
+/*
+ * DHT22Node.hpp
+ * Homie Node for DHT-22 sensors using Adafruit DHT library.
+ *
+ * Version: 1.0
+ * Author: Lübbe Onken (http://github.com/luebbe)
+ */
+
+#pragma once
+
+#include <Adafruit_Sensor.h>
+#include <DHT_U.h>
+
+#include "SensorNode.hpp"
+#include "constants.hpp"
+
+#define DEFAULTPIN -1
+
+class DHT22Node : public SensorNode
+{
+private:
+  const float cMinTemp = -40.0;
+  const float cMaxTemp = 125.0;
+  const char *cCaption = "• DHT22 sensor";
+  const char *cIndent = "  ◦ ";
+
+  int _sensorPin;
+  unsigned long _measurementInterval;
+  unsigned long _lastMeasurement;
+
+  float temperature = NAN;
+  float humidity = NAN;
+
+  DHT *dht = NULL;
+
+  void printCaption();
+  void send();
+
+protected:
+  virtual void setup() override;
+  virtual void loop() override;
+
+public:
+  explicit DHT22Node(const char *name,
+                     const int sensorPin = DEFAULTPIN,
+                     const int measurementInterval = MEASUREMENT_INTERVAL);
+
+  float getHumidity() const { return humidity; }
+  float getTemperature() const { return temperature; }
+};
diff --git a/lib/HomieNodes/PingNode.cpp b/lib/HomieNodes/PingNode.cpp
new file mode 100644
index 0000000..c6caba2
--- /dev/null
+++ b/lib/HomieNodes/PingNode.cpp
@@ -0,0 +1,147 @@
+/*
+ * BME280Node.cpp
+ * Homie Node for BME280 sensors using Adafruit BME280 library.
+ *
+ * Version: 1.1
+ * Author: Lübbe Onken (http://github.com/luebbe)
+ * Author: Markus Haack (http://github.com/mhaack)
+ */
+
+#include "PingNode.hpp"
+#include <Homie.h>
+
+bool checkBounds(float value, float min, float max) {
+  return !isnan(value) && value >= min &&  value <= max;
+}
+
+PingNode::PingNode(const char *name, const int triggerPin, const int echoPin,
+                     const int measurementInterval, const int publishInterval)
+    : SensorNode(name, "RCW-0001"),
+      _triggerPin(triggerPin), _echoPin(echoPin),_lastMeasurement(0), _lastPublish(0)
+{
+  _measurementInterval = (measurementInterval > MIN_INTERVAL) ? measurementInterval : MIN_INTERVAL;
+  _publishInterval = (publishInterval > int(_measurementInterval)) ? publishInterval : _measurementInterval;
+  setMicrosecondsToMetersFactor(20);
+
+  if (_triggerPin > DEFAULTPIN && _echoPin > DEFAULTPIN) {
+    sonar = new NewPing(_triggerPin,_echoPin,cMaxDistance*100.0);
+  }
+
+  advertise(cDistanceTopic)
+    .setDatatype("float")
+    .setFormat("0:3")
+    .setUnit(cUnitMeter);
+  advertise(cPingTopic)
+    .setDatatype("float")
+    .setUnit(cUnitMicrosecond);
+  advertise(cStatusTopic)
+      .setDatatype("enum")
+      .setFormat("error, ok");
+  advertise(cChangedTopic)
+    .setName("Obstacle changed")
+    .setDatatype("boolean"); 
+}
+
+void PingNode::printCaption()
+{
+  Homie.getLogger() << cCaption << " triggerpin[" << _triggerPin << "], echopin[" << _echoPin << "]:" << endl;
+}
+
+void PingNode::send()
+{
+  printCaption();
+  Homie.getLogger() << cIndent << "Ping: " << _ping_us << " " << cUnitMicrosecond << endl;
+  Homie.getLogger() << cIndent << "Distance: " << _distance << " " << cUnitMeter << endl;
+  bool valid = _distance > 0;
+  Homie.getLogger() << cIndent << "Status: " << (valid ? "ok" : "error") << endl;
+  bool changed = signalChange(_distance, _lastDistance);
+  Homie.getLogger() << cIndent << "Changed: " << (changed ? "true" : "false") << " " << endl;
+  if (Homie.isConnected())
+  {
+    setProperty(cStatusTopic).send(valid ? "ok" : "error");
+    if (valid) {
+      setProperty(cDistanceTopic).send(String(_distance));
+      setProperty(cChangedTopic).send(changed ? "true": "false");
+    }
+  }
+  if (changed)
+  {
+    _changeHandler();
+  }
+  if (valid) {
+    _lastDistance = _distance;
+    _distance = -1;
+  }
+    
+}
+
+void PingNode::loop()
+{
+  if (sonar) {
+    if (millis() - _lastMeasurement >= _measurementInterval * 1000UL || _lastMeasurement == 0)
+    {
+      float ping_us = sonar->ping_median();
+      // Calculating the distance @ 10 °C from d = t_ping /2 * c => t_ping /2 * 337 [m/s] => t_ping_us / 1e-6 * 1/2 * 337 
+      float newDistance = ping_us*0.0001685;
+      fixRange(&newDistance, cMinDistance, cMaxDistance);
+      if (newDistance > 0) {
+        _ping_us = ping_us;
+        _distance = newDistance;
+      }
+      _lastMeasurement = millis();
+    }
+
+    if (millis() - _lastPublish >= _publishInterval * 1000UL || _lastPublish == 0)
+      if (_distance > 0) {
+        	send();
+        _lastPublish = millis();
+        _distance = 0;
+      }
+  }
+}
+
+void PingNode::onReadyToOperate()
+{
+  if (Homie.isConnected())
+  {
+    setProperty(cStatusTopic).send("ok");
+  }
+};
+
+void PingNode::setup()
+{
+  printCaption();
+  Homie.getLogger() << cIndent << "Reading interval: " << _measurementInterval << " s" << endl;
+  Homie.getLogger() << cIndent << "Publish interval: " << _publishInterval << " s" << endl;
+}
+
+void PingNode::setMicrosecondsToMetersFactor(float temperatureCelcius)
+{
+  //float soundSpeed = 337.0; // @ 10°C
+  float soundSpeed = 331.4 * 0.6*temperatureCelcius;
+  // Calculating the distance from d = t_ping /2 * c => t_ping /2 * 337 [m/s] => t_ping_us / 1e-6 * 1/2 * 337
+  _microseconds2meter = 0.5e-6 * soundSpeed;  
+}
+
+float PingNode::getRawEchoTime() {
+    // Clears the trigPin
+  digitalWrite(_triggerPin, LOW);
+  delayMicroseconds(2);
+
+  // Sets the trigPin on HIGH state for 10 micro seconds
+  digitalWrite(_triggerPin, HIGH);
+  delayMicroseconds(10);
+  digitalWrite(_triggerPin, LOW);
+
+  // Reads the echoPin, returns the sound wave travel time in microseconds
+  return pulseIn(_echoPin, HIGH);
+}
+
+bool PingNode::signalChange(float distance, float lastDistance) {
+  return fabs(distance - lastDistance) > cMinimumChange;
+}
+
+PingNode& PingNode::setChangeHandler(const ChangeHandler& changeHandler) {
+  _changeHandler = changeHandler;
+  return *this;
+}
diff --git a/lib/HomieNodes/PingNode.hpp b/lib/HomieNodes/PingNode.hpp
new file mode 100644
index 0000000..9241d49
--- /dev/null
+++ b/lib/HomieNodes/PingNode.hpp
@@ -0,0 +1,71 @@
+/*
+ * BME280Node.h
+ * Homie Node for BME280 sensors using Adafruit BME280 library.
+ *
+ * Version: 1.1
+ * Author: Lübbe Onken (http://github.com/luebbe)
+ * Author: Markus Haack (http://github.com/mhaack)
+ */
+
+#pragma once
+
+#include "NewPing.h"
+
+#include "SensorNode.hpp"
+#include "constants.hpp"
+
+#define DEFAULTPIN -1
+
+class PingNode : public SensorNode
+{
+public:
+  typedef std::function<void()> ChangeHandler;
+private:
+  const float cMinDistance = 0.0;
+  const float cMaxDistance = 3.0;
+  const float cMinimumChange = 0.2;
+
+  static const int MIN_INTERVAL = 1; // in seconds
+  const char *cCaption = "• RCW-0001 sensor";
+  const char *cIndent = "  ◦ ";
+
+  int _triggerPin;
+  int _echoPin;
+  float _microseconds2meter;
+  
+  unsigned long _measurementInterval;
+  unsigned long _lastMeasurement;
+  unsigned long _publishInterval;
+  unsigned long _lastPublish;
+
+  NewPing* sonar;
+  float _distance = NAN;
+  int _ping_us = NAN;
+  float _lastDistance = 0;
+  ChangeHandler _changeHandler = [](){};
+  
+  float getRawEchoTime();
+  void setMicrosecondsToMetersFactor(float temperatureCelcius);
+  bool signalChange(float distance, float lastDistance);
+  void printCaption();
+  void send();
+  
+protected:
+  virtual void setup() override;
+  virtual void loop() override;
+  virtual void onReadyToOperate() override;
+  static const int DEFAULT_MEASUREMENT_INTERVAL = 1;
+  static const int DEFAULT_PUBLISH_INTERVAL = 5;
+
+
+public:
+  explicit PingNode(const char *name,
+                     const int triggerPin = DEFAULTPIN,
+                     const int echoPin = DEFAULTPIN,
+                     const int measurementInterval = DEFAULT_MEASUREMENT_INTERVAL,
+                     const int publishInterval = DEFAULT_PUBLISH_INTERVAL);
+
+  float getDistance() const { return _distance; }
+  void setTemperature(float temperatureCelcius) { setMicrosecondsToMetersFactor(temperatureCelcius); }
+  PingNode& setChangeHandler(const ChangeHandler& changeHandler);
+};
diff --git a/lib/HomieNodes/RelayNode.cpp b/lib/HomieNodes/RelayNode.cpp
new file mode 100644
index 0000000..4a04b57
--- /dev/null
+++ b/lib/HomieNodes/RelayNode.cpp
@@ -0,0 +1,179 @@
+/*
+ * RelayNode.cpp
+ * Homie Node for a Relay with optional status indicator LED
+ *
+ * Version: 1.1
+ * Author: Lübbe Onken (http://github.com/luebbe)
+ */
+
+#include "RelayNode.hpp"
+
+RelayNode::RelayNode(const char *name, const int relayPin, const int ledPin, const bool reverseSignal)
+    : HomieNode(name, "RelayNode", "actor")
+{
+  _relayPin = relayPin;
+  _ledPin = ledPin;
+  if (reverseSignal)
+  {
+    _relayOnValue = LOW;
+    _relayOffValue = HIGH;
+  }
+  else
+  {
+    _relayOnValue = HIGH;
+    _relayOffValue = LOW;
+  }
+  advertise("on")
+      .setDatatype("boolean")
+      .settable();
+
+  advertise("timeout")
+      .setDatatype("integer")
+      .settable();
+}
+
+HomieInternals::Uptime relayUptime;
+
+bool RelayNode::handleOnOff(const String &value)
+{
+  if (value == "true" || value == "false")
+  {
+    setRelay(value == "true");
+    return true;
+  }
+  else
+  {
+    return false;
+  }
+}
+
+#define IS_INTEGER(s) (s == String(s.toInt()))
+
+bool RelayNode::handleTimeout(const String &value)
+{
+  if (IS_INTEGER(value))
+  {
+    long timeout = value.toInt();
+    if (timeout > 0)
+    {
+      setRelay(true, timeout);
+      return true;
+    }
+  }
+  return false;
+}
+
+bool RelayNode::handleInput(const HomieRange &range, const String &property, const String &value)
+{
+  Homie.getLogger() << "Message: " << property << " " << value << endl;
+
+  if (property.equals("on"))
+  {
+    return handleOnOff(value);
+  }
+  else if (property.equals("timeout"))
+  {
+    return handleTimeout(value);
+  }
+  else
+  {
+    return false;
+  }
+}
+
+void RelayNode::printCaption()
+{
+  Homie.getLogger() << cCaption << endl;
+}
+
+void RelayNode::setLed(bool on)
+{
+  if (_ledPin > DEFAULTPIN)
+  {
+    digitalWrite(_ledPin, on ? LOW : HIGH); // LOW = LED on
+  }
+}
+
+void RelayNode::setRelay(bool on, long timeoutSecs)
+{
+  printCaption();
+
+  if (_relayPin > DEFAULTPIN)
+  {
+    setRelayState(on);
+    if (on && timeoutSecs > 0)
+    {
+      _timeout = relayUptime.getSeconds() + timeoutSecs;
+    }
+    else
+    {
+      _timeout = 0;
+    }
+    sendState();
+  }
+  else
+  {
+    Homie.getLogger() << cIndent << "No Relay Pin!" << endl;
+  }
+  setLed(on);
+}
+
+void RelayNode::sendState()
+{
+  bool on = getRelayState();
+  Homie.getLogger() << cIndent << "Relay is " << (on ? "on" : "off") << endl;
+  if (Homie.isConnected())
+  {
+    setProperty("on").send(on ? "true" : "false");
+    setProperty("timeout").send(String(long(_timeout)));
+  }
+}
+
+void RelayNode::setRelayState(bool on)
+{
+  digitalWrite(_relayPin, on ? _relayOnValue : _relayOffValue);
+}
+
+bool RelayNode::getRelayState()
+{
+  return digitalRead(_relayPin) == _relayOnValue;
+}
+
+void RelayNode::toggleRelay()
+{
+  setRelay(!getRelayState());
+}
+
+void RelayNode::setupRelay()
+{
+  pinMode(_relayPin, OUTPUT);
+}
+
+void RelayNode::setup()
+{
+  printCaption();
+
+  Homie.getLogger() << cIndent << "Relay Pin: " << _relayPin << endl
+                    << cIndent << "Led Pin  : " << _ledPin << endl;
+
+  if (_ledPin > DEFAULTPIN)
+  {
+    pinMode(_ledPin, OUTPUT);
+    setLed(false);
+  }
+
+  if (_relayPin > DEFAULTPIN)
+  {
+    setupRelay();
+    setRelay(false);
+  }
+}
+
+void RelayNode::loop()
+{
+  relayUptime.update();
+  if ((_timeout > 0) && getRelayState() && (_timeout < relayUptime.getSeconds()))
+  {
+    setRelay(false);
+  }
+}
diff --git a/lib/HomieNodes/RelayNode.hpp b/lib/HomieNodes/RelayNode.hpp
new file mode 100644
index 0000000..43feb03
--- /dev/null
+++ b/lib/HomieNodes/RelayNode.hpp
@@ -0,0 +1,49 @@
+/*
+ * RelayNode.hpp
+ * Homie Node for a Relay with optional status indicator LED
+ *
+ * Version: 1.0
+ * Author: Lübbe Onken (http://github.com/luebbe)
+ */
+
+#pragma once
+
+#include <Homie.hpp>
+
+#define DEFAULTPIN -1
+
+class RelayNode : public HomieNode
+{
+private:
+  const char *cCaption = "• Relay:";
+  const char *cIndent = "  ◦ ";
+
+  int _relayPin;
+  int _ledPin;
+
+  uint8_t _relayOnValue;
+  uint8_t _relayOffValue;
+  uint64_t _timeout;
+
+  bool handleOnOff(const String &value);
+  bool handleTimeout(const String &value);
+
+  void printCaption();
+  void sendState();
+
+  void setupRelay();
+  bool getRelayState();
+  void setRelayState(bool on);
+
+  void setLed(bool on);
+
+protected:
+  virtual bool handleInput(const HomieRange &range, const String &property, const String &value) override;
+  virtual void setup() override;
+  virtual void loop() override;
+
+public:
+  explicit RelayNode(const char *name, const int relayPin = DEFAULTPIN, const int ledPin = DEFAULTPIN, const bool reverseSignal = false);
+  void setRelay(bool on, long timeoutSecs = 0);
+  void toggleRelay();
+};
diff --git a/lib/HomieNodes/SensorNode.cpp b/lib/HomieNodes/SensorNode.cpp
new file mode 100644
index 0000000..bb630cd
--- /dev/null
+++ b/lib/HomieNodes/SensorNode.cpp
@@ -0,0 +1,48 @@
+/*
+ * SensorNode.hpp
+ * Homie Node for genric sensors.
+ * Provides a limit method for measurement values
+ *
+ * Version: 1.0
+ * Author: Lübbe Onken (http://github.com/luebbe)
+ */
+
+#include "SensorNode.hpp"
+
+SensorNode::SensorNode(const char *name, const char *type)
+    : HomieNode(name, type, "sensor")
+{
+}
+
+float SensorNode::computeAbsoluteHumidity(float temperature, float percentHumidity) {
+  // Calculate the absolute humidity in g/m³
+  // https://carnotcycle.wordpress.com/2012/08/04/how-to-convert-relative-humidity-to-absolute-humidity/
+
+  float absHumidity;
+  float absTemperature;
+  absTemperature = temperature + 273.15;
+
+  absHumidity = 6.112;
+  absHumidity *= exp((17.67 * temperature) / (243.5 + temperature));
+  absHumidity *= percentHumidity;
+  absHumidity *= 2.1674;
+  absHumidity /= absTemperature;
+
+  return absHumidity;
+}
+
+void SensorNode::fixRange(float *value, float min, float max)
+{
+  if (isnan(*value))
+  {
+    return;
+  }
+  else if (*value < min)
+  {
+    *value = min;
+  }
+  else if (*value > max)
+  {
+    *value = max;
+  };
+}
diff --git a/lib/HomieNodes/SensorNode.hpp b/lib/HomieNodes/SensorNode.hpp
new file mode 100644
index 0000000..05de251
--- /dev/null
+++ b/lib/HomieNodes/SensorNode.hpp
@@ -0,0 +1,26 @@
+/*
+ * SensorNode.hpp
+ * Homie Node for genric sensors.
+ * Provides a limit method for measurement values
+ *
+ * Version: 1.0
+ * Author: Lübbe Onken (http://github.com/luebbe)
+ */
+
+#pragma once
+
+#include <Homie.hpp>
+
+class SensorNode : public HomieNode
+{
+protected:
+  const float cMinHumid = 0.0;
+  const float cMaxHumid = 100.0;
+  static const int MEASUREMENT_INTERVAL = 300;
+
+  float computeAbsoluteHumidity(float temperature, float percentHumidity);
+  void fixRange(float *value, float min, float max);
+
+public:
+  explicit SensorNode(const char *name, const char *type);
+};
diff --git a/lib/HomieNodes/constants.hpp b/lib/HomieNodes/constants.hpp
new file mode 100644
index 0000000..dec01d5
--- /dev/null
+++ b/lib/HomieNodes/constants.hpp
@@ -0,0 +1,25 @@
+// Units
+#define cUnitDegrees "°C"
+#define cUnitHpa "hPa"
+#define cUnitMgm3 "g/m³"
+#define cUnitPercent "%"
+#define cUnitVolt "V"
+#define cUnitMeter "m"
+#define cUnitMicrosecond "μs"
+
+// Topics
+#define cStatusTopic "status"
+#define cUnitTopic "unit"
+#define cTemperatureTopic "temperature"
+#define cTemperatureUnitTopic cTemperatureTopic "/" cUnitTopic
+#define cHumidityTopic "humidity"
+#define cPressureTopic "pressure"
+#define cAbsHumidityTopic "abshumidity"
+#define cVoltageTopic "voltage"
+#define cBatteryLevelTopic "batterylevel"
+#define cDistanceTopic "distance"
+#define cPingTopic "ping"
+#define cChangedTopic "changed"
+#define cValidTopic "valid"
+
+
diff --git a/platformio.ini b/platformio.ini
index b487207..8b7fc79 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -17,4 +17,5 @@ monitor_speed = 115200
 lib_deps =
   NewPing
   Homie
-
+  DHT sensor library
+  Adafruit Unified Sensor
diff --git a/src/main.cpp b/src/main.cpp
index b7c71a4..12e40d2 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,28 +1,38 @@
-#include <NewPing.h>
 #include <Homie.h>
 
+#include "PingNode.hpp"
+#include "RelayNode.hpp"
+#include "DHT22Node.hpp"
+
 #define TURN_ON LOW
 #define TURN_OFF HIGH
 
-const int trigPin = D1;  //D1
-const int echoPin = D2;  //D2
+const int trigPin = D1;
+const int echoPin = D2;
+const int relayPin = 14; // D5
+const int dhtPin = D7;                            ;
 const int ledPin  = LED_BUILTIN; 
-const float minDistance = 0.01;
-const float maxDistance = 4.0;
-const float minimumChange = 0.2;
 
-#define MEASURE_INTERVAL 1000 // ms
-#define PUBLISH_INTERVAL 5000 // ms
+unsigned long HEARTBEAT_INTERVAL = 5;
+unsigned long lastHeartbeat = 0;
 
-NewPing sonar(trigPin,echoPin,maxDistance*100.0);
-HomieNode obstacleNode("obstacle", "Obstacle", "object");
+PingNode obstacleNode("obstacle",trigPin,echoPin);
+DHT22Node airNode("air",dhtPin,20);
+RelayNode relayNode("relay",relayPin,ledPin);
 
-void signal_led(bool ons = true);
+void signal_led(bool on = true);
 void heartbeat_led(int times = 2);
-void longbeat_led();
-void loopHandler();
-void setupHandler();
-float readDistance();
+
+void changeHandler() {
+  signal_led();
+}
+
+void loopHandler() {
+  if (millis() - lastHeartbeat > HEARTBEAT_INTERVAL * 1000UL || lastHeartbeat == 0) {
+    heartbeat_led();
+    lastHeartbeat = millis();
+  }
+}
 
 void setup() {
   Serial.begin(115200);
@@ -31,14 +41,9 @@ void setup() {
   pinMode(ledPin, OUTPUT);
 
   Homie_setBrand("EtxeanIoT");
-  Homie_setFirmware("etxean-distancesensor", "1.0.4"); 
+  Homie_setFirmware("etxean-garagesensor", "1.0.5"); 
   Homie.setLoopFunction(loopHandler);
-  obstacleNode
-    .advertise("distance").setName("Distance").setDatatype("float").setUnit("m");
-  obstacleNode
-    .advertise("valid").setName("Valid measurement").setDatatype("boolean");
-  obstacleNode
-    .advertise("changed").setName("Obstacle changed").setDatatype("boolean");  
+  obstacleNode.setChangeHandler(changeHandler); 
   Homie.setup();
 }
 
@@ -46,86 +51,9 @@ void loop() {
   Homie.loop();
 }
 
-long lastPublish = 0;
-long lastMeasurement = 0;
-float lastDistance = 0.0;
-float validDistance = -1;
-
-bool checkBounds(float value, float min, float max) {
-  return !isnan(value) && value >= min &&  value <= max;
-}
-
-bool signalChange(float distance, float lastDistance) {
-  return fabs(distance - lastDistance) > minimumChange;
-}
-
-String toPayload(bool value)
-{
-  return value ? "true" : "false";  
-}
-
-void loopHandler() {
-  if (millis() - lastMeasurement >= MEASURE_INTERVAL) {
-    float distance = readDistance();
-    //float distance = random(5,400)/100.0;
-    Homie.getLogger() << "Distance: " << distance << " m";
-    bool valid = checkBounds(distance,minDistance,maxDistance);
-    Homie.getLogger() << ", valid = " << toPayload(valid) << endl;
-    if (valid)
-      validDistance = distance;
-    lastMeasurement = millis();
-  }
-  if (millis() - lastPublish >= PUBLISH_INTERVAL) {
-    heartbeat_led();
-
-    bool valid = validDistance > 0;
-    obstacleNode.setProperty("valid").send(toPayload(valid));
-    if (valid)
-    {
-      Homie.getLogger() << "Publish distance: " << validDistance << " m";
-      obstacleNode.setProperty("distance").send(String(validDistance));
-      bool changed = signalChange(validDistance, lastDistance);
-      obstacleNode.setProperty("changed").send(toPayload(changed));
-      if (changed)
-      {
-        signal_led();      
-         Homie.getLogger() << ", changed" << endl;
-      }
-      lastDistance = validDistance;
-      validDistance = -1;      
-    }
-    lastPublish = millis();
-  }
-}
-
-float getEchoTime() {
-    // Clears the trigPin
-  digitalWrite(trigPin, LOW);
-  delayMicroseconds(2);
-
-  // Sets the trigPin on HIGH state for 10 micro seconds
-  digitalWrite(trigPin, HIGH);
-  delayMicroseconds(10);
-  digitalWrite(trigPin, LOW);
-
-  // Reads the echoPin, returns the sound wave travel time in microseconds
-  return pulseIn(echoPin, HIGH);
-}
-
-float readDistance() {
-  //auto ping_us = getEchoTime();
-  auto ping_us = sonar.ping_median();
-  // Calculating the distance @ 10 °C from d = t_ping /2 * c => t_ping /2 * 337 [m/s] => t_ping_us / 1e-6 * 1/2 * 337 
-  auto computedDistance = ping_us*0.0001685;
-  return computedDistance;
-}
-
 void signal_led(bool on) 
 {
-  if (on)
-    digitalWrite(ledPin, TURN_ON);
-  else
-    digitalWrite(ledPin, TURN_OFF); 
+  digitalWrite(ledPin, on ? TURN_ON : TURN_OFF);
 }
 
 void heartbeat_led(int times)