diff --git a/src/NodeHeizung.h b/src/NodeHeizung.h
index 3ea35ad..aa75e10 100644
--- a/src/NodeHeizung.h
+++ b/src/NodeHeizung.h
@@ -57,39 +57,28 @@ public:
     //
   };
 
-  void setup() override {
-    // TODO
+  Sensor *getSensor(const int index) override {
+    switch (index) {
+      case 0: return &keller;
+      case 1: return &abgas;
+      case 3: return &pufferVorlauf;
+      case 4: return &pufferRuecklauf;
+      case 5: return &pufferEingang;
+      case 6: return &pufferSpeicher;
+      case 7: return &pufferAusgang;
+      case 8: return &pufferZirkulation;
+      case 9: return &heizkreisVorlauf;
+      case 10: return &heizkreisRuecklauf;
+      case 11: return &abwasser;
+      case 12: return &reserve;
+      default: return nullptr;
+    }
   }
 
-  void loop() override {
-    keller.loop();
-    abgas.loop();
+protected:
+
+  void loopBeforeSensors() override {
     dallas.loop();
-    pufferVorlauf.loop();
-    pufferRuecklauf.loop();
-    pufferEingang.loop();
-    pufferSpeicher.loop();
-    pufferAusgang.loop();
-    pufferZirkulation.loop();
-    heizkreisVorlauf.loop();
-    heizkreisRuecklauf.loop();
-    abwasser.loop();
-    reserve.loop();
-  }
-
-  void toJson(JsonDocument& json) override {
-    keller.toJson(json);
-    abgas.toJson(json);
-    pufferVorlauf.toJson(json);
-    pufferRuecklauf.toJson(json);
-    pufferEingang.toJson(json);
-    pufferSpeicher.toJson(json);
-    pufferAusgang.toJson(json);
-    pufferZirkulation.toJson(json);
-    heizkreisVorlauf.toJson(json);
-    heizkreisRuecklauf.toJson(json);
-    abwasser.toJson(json);
-    reserve.toJson(json);
   }
 
 };
diff --git a/src/NodeTest.h b/src/NodeTest.h
index 38668f3..959a326 100644
--- a/src/NodeTest.h
+++ b/src/NodeTest.h
@@ -1,8 +1,6 @@
 #ifndef NODE_TEST_H
 #define NODE_TEST_H
 
-#include <WiFi.h>
-
 #include "patrix/Node.h"
 #include "patrix/sensor/Dallas.h"
 #include "patrix/sensor/DallasSensor.h"
@@ -28,30 +26,18 @@ public:
     //
   };
 
-  void setup() override {
-    // TODO
-  }
-
-  void loop() override {
-    dallas.loop();
-    test.loop();
-    testraum.loop();
-    const auto tt = test.isDue();
-    const auto tr = testraum.isDue();
-    if (tt || tr) {
-      JsonDocument json;
-      json["timestamp"] = time(nullptr);
-      toJson(json);
-      if (mqttPublish(WiFiClass::getHostname(), "state", json)) {
-        test.markSent();
-        testraum.markSent();
-      }
+  Sensor *getSensor(const int index) override {
+    switch (index) {
+      case 0: return &test;
+      case 1: return &testraum;
+      default: return nullptr;
     }
   }
 
-  void toJson(JsonDocument& json) override {
-    test.toJson(json);
-    testraum.toJson(json);
+protected:
+
+  void loopBeforeSensors() override {
+    dallas.loop();
   }
 
 };
diff --git a/src/patrix/Node.h b/src/patrix/Node.h
index 26fb024..079f854 100644
--- a/src/patrix/Node.h
+++ b/src/patrix/Node.h
@@ -1,7 +1,7 @@
 #ifndef NODE_H
 #define NODE_H
 
-#include <ArduinoJson.h>
+#include "sensor/Sensor.h"
 
 class Node {
 
@@ -9,11 +9,47 @@ public:
 
   virtual ~Node() = default;
 
-  virtual void setup() = 0;
+  void toJson(const JsonObject& json) {
+    auto index = 0;
+    Sensor *sensor;
+    while ((sensor = getSensor(index++)) != nullptr) {
+      sensor->toJson(json[sensor->getName()].to<JsonObject>());
+    }
+  }
 
-  virtual void loop() = 0;
+  void send() {
+    JsonDocument json;
+    toJson(json.to<JsonObject>());
+    mqttPublish(String(WiFi.getHostname()) + "/json", json);
+  }
 
-  virtual void toJson(JsonDocument& json) = 0;
+  void loop() {
+    loopBeforeSensors();
+    const auto changed = loopSensors();
+    if (changed) {
+      send();
+    }
+  }
+
+  virtual void setup() {}
+
+  virtual void loopBeforeSensors() {}
+
+  virtual Sensor *getSensor(int index) = 0;
+
+private:
+
+  bool loopSensors() {
+    auto changed = false;
+    auto index = 0;
+    Sensor *sensor;
+    while ((sensor = getSensor(index++)) != nullptr) {
+      if (sensor->loop()) {
+        changed = true;
+      }
+    }
+    return changed;
+  }
 
 };
 
diff --git a/src/patrix/http.cpp b/src/patrix/http.cpp
index ca4f444..79ab274 100644
--- a/src/patrix/http.cpp
+++ b/src/patrix/http.cpp
@@ -3,12 +3,46 @@
 #include <ESPAsyncWebServer.h>
 
 #include "log.h"
+#include "main.h"
 #include "system.h"
 
 AsyncWebServer server(80);
 
+void printValues(AsyncResponseStream *const response, Sensor *sensor) {
+  auto valueIndex = 0;
+  Value *value;
+  response->println("<ul>");
+  while ((value = sensor->getValue(valueIndex++)) != nullptr) {
+    response->println("<li>");
+    response->printf("<h2>%s = %.1f</h2>\n", value->getName(), value->getCurrentValue());
+    response->println("</li>");
+  }
+  response->println("</ul>");
+}
+
+void printSensors(AsyncResponseStream *const response) {
+  auto sensorIndex = 0;
+  Sensor *sensor;
+  response->println("<ul>");
+  while ((sensor = node.getSensor(sensorIndex++)) != nullptr) {
+    response->println("<li>");
+    response->printf("<h3>%s</h3>\n", sensor->getName());
+    printValues(response, sensor);
+    response->println("</li>");
+  }
+  response->println("</ul>");
+}
+
 void httpIndex(AsyncWebServerRequest *request) {
-  request->send(200, "text/html", R"(<a href="/reboot">reboot</a>)");
+  const auto response = request->beginResponseStream("text/html");
+  response->println("<!DOCTYPE html><html><head>");
+  response->println("<title>TEST</title>");
+  response->println("</head>");
+  response->println("<body>");
+  response->println("<a href='reboot'>Neustart</a>");
+  printSensors(response);
+  response->println("</body></html>");
+  request->send(response);
 }
 
 void httpReboot(AsyncWebServerRequest *request) {
@@ -16,6 +50,7 @@ void httpReboot(AsyncWebServerRequest *request) {
   request->redirect("/");
   request->client()->close();
   yield();
+  delay(500);
 
   restart();
 }
diff --git a/src/patrix/main.cpp b/src/patrix/main.cpp
index 773afdf..cb0729c 100644
--- a/src/patrix/main.cpp
+++ b/src/patrix/main.cpp
@@ -1,5 +1,6 @@
 #include <Arduino.h>
 
+#include "main.h"
 #include "boot.h"
 #include "wifi.h"
 #include "http.h"
@@ -9,15 +10,12 @@
 #include "sensor/DHT22.h"
 #include "sensor/Max6675Sensor.h"
 
-#include "NodeTest.h"
-#include "NodeHeizung.h"
-
 #ifdef NODE_TEST
-auto node = NodeTest();
+NodeTest node = NodeTest();
 #endif
 
 #ifdef NODE_HEIZUNG
-auto node = NodeHeizung();
+NodeHeizung node = NodeHeizung();
 #endif
 
 void setup() {
diff --git a/src/patrix/main.h b/src/patrix/main.h
new file mode 100644
index 0000000..21fb2c8
--- /dev/null
+++ b/src/patrix/main.h
@@ -0,0 +1,15 @@
+#ifndef MAIN_H
+#define MAIN_H
+
+#include "NodeTest.h"
+#include "NodeHeizung.h"
+
+#ifdef NODE_TEST
+extern NodeTest node;
+#endif
+
+#ifdef NODE_HEIZUNG
+extern NodeHeizung node;
+#endif
+
+#endif
diff --git a/src/patrix/mqtt.cpp b/src/patrix/mqtt.cpp
index 10ebe79..ed11b3f 100644
--- a/src/patrix/mqtt.cpp
+++ b/src/patrix/mqtt.cpp
@@ -46,11 +46,13 @@ void mqttLoop() {
   }
 }
 
-bool mqttPublish(const char *topic0, const char *topic1, const JsonDocument& json) {
-  char topic[256];
-  snprintf(topic, sizeof(topic), "%s/%s", topic0, topic1);
+bool mqttPublish(const String& topic, const double value, const bool retained) {
+  return mqtt.publish(topic.c_str(), String(value).c_str(), retained);
+}
 
+
+bool mqttPublish(const String& topic, const JsonDocument& json) {
   char buffer[512];
   serializeJson(json, buffer);
-  return mqtt.publish(topic, buffer);
+  return mqtt.publish(topic.c_str(), buffer);
 }
diff --git a/src/patrix/mqtt.h b/src/patrix/mqtt.h
index 6c259fa..5335539 100644
--- a/src/patrix/mqtt.h
+++ b/src/patrix/mqtt.h
@@ -5,6 +5,8 @@
 
 void mqttLoop();
 
-bool mqttPublish(const char *topic0, const char *topic1, const JsonDocument& json);
+bool mqttPublish(const String& topic, const double value, bool retained);
+
+bool mqttPublish(const String& topic, const JsonDocument& json);
 
 #endif
diff --git a/src/patrix/sensor/DHT22.h b/src/patrix/sensor/DHT22.h
index d070517..b77eb99 100644
--- a/src/patrix/sensor/DHT22.h
+++ b/src/patrix/sensor/DHT22.h
@@ -1,10 +1,11 @@
 #ifndef DHT22_H
 #define DHT22_H
 
-#include "dht_nonblocking.h"
-
 #include "Sensor.h"
 
+#include "dht_nonblocking.h"
+#include "Value.h"
+
 class DHT22 final : public Sensor {
 
   DHT_nonblocking sensor;
@@ -32,7 +33,7 @@ public:
     //
   }
 
-  bool loop() override {
+  void loopBeforeValues() override {
     float t, hr;
     if (sensor.measure(&t, &hr)) {
       temperature.update(t);
@@ -40,26 +41,15 @@ public:
       humidityAbsolute.update(6.112 * exp(17.67 * t / (243.5 + t)) * hr * 2.1674 / (t + 273.15));
       info("%s: temperature=%.1f^C, humidityRelative=%.0f%%, humidityAbsolute=%.0fmg/L", name, temperature.getCurrentValue(), humidityRelative.getCurrentValue(), humidityAbsolute.getCurrentValue());
     }
-    return false; // TODO
   }
 
-  void toJson(JsonDocument& json) override {
-    json[String(name) + "/" + temperature.getName()] = temperature.getCurrentValue();
-    json[String(name) + "/" + humidityRelative.getName()] = humidityRelative.getCurrentValue();
-    json[String(name) + "/" + humidityAbsolute.getName()] = humidityAbsolute.getCurrentValue();
-  }
-
-  bool isDue() override {
-    const auto tp = temperature.isDue();
-    const auto hr = humidityRelative.isDue();
-    const auto ha = humidityAbsolute.isDue();
-    return tp || hr || ha;
-  }
-
-  void markSent() override {
-    temperature.markSent();
-    humidityRelative.markSent();
-    humidityAbsolute.markSent();
+  Value *getValue(const int index) override {
+    switch (index) {
+      case 0: return &temperature;
+      case 1: return &humidityRelative;
+      case 2: return &humidityAbsolute;
+      default: return nullptr;
+    }
   }
 
 };
diff --git a/src/patrix/sensor/DallasSensor.h b/src/patrix/sensor/DallasSensor.h
index 48e1d56..191fde6 100644
--- a/src/patrix/sensor/DallasSensor.h
+++ b/src/patrix/sensor/DallasSensor.h
@@ -30,23 +30,17 @@ public:
     //
   }
 
-  bool loop() override {
+  void loopBeforeValues() override {
     if (sensors.isConverted()) {
       temperature.update(sensors.read(address));
     }
-    return false; // TODO
   }
 
-  void toJson(JsonDocument& json) override {
-    json[String(name) + "/" + temperature.getName()] = temperature.getCurrentValue();
-  }
-
-  bool isDue() override {
-    return temperature.isDue();
-  }
-
-  void markSent() override {
-    temperature.markSent();
+  Value *getValue(const int index) override {
+    switch (index) {
+      case 0: return &temperature;
+      default: return nullptr;
+    }
   }
 
 };
diff --git a/src/patrix/sensor/Max6675Sensor.h b/src/patrix/sensor/Max6675Sensor.h
index e52db41..bd9cb55 100644
--- a/src/patrix/sensor/Max6675Sensor.h
+++ b/src/patrix/sensor/Max6675Sensor.h
@@ -30,22 +30,15 @@ public:
     //
   }
 
-  bool loop() override {
-    float current = sensor.readCelsius();
-    temperature.update(current);
-    return false; // TODO
+  void loopBeforeValues() override {
+    temperature.update(sensor.readCelsius());
   }
 
-  void toJson(JsonDocument& json) override {
-    json[String(name) + "/" + temperature.getName()] = temperature.getCurrentValue();
-  }
-
-  bool isDue() override {
-    return temperature.isDue();
-  }
-
-  void markSent() override {
-    temperature.markSent();
+  Value *getValue(const int index) override {
+    switch (index) {
+      case 0: return &temperature;
+      default: return nullptr;
+    }
   }
 
 };
diff --git a/src/patrix/sensor/Sensor.h b/src/patrix/sensor/Sensor.h
index b04e20b..53b16ad 100644
--- a/src/patrix/sensor/Sensor.h
+++ b/src/patrix/sensor/Sensor.h
@@ -1,7 +1,8 @@
 #ifndef SENSOR_H
 #define SENSOR_H
 
-#include <ArduinoJson.h>
+#include "Value.h"
+#include "../mqtt.h"
 
 class Sensor {
 
@@ -17,13 +18,50 @@ public:
 
   virtual ~Sensor() = default;
 
-  virtual bool loop() = 0;
+  const char *getName() const {
+    return name;
+  }
 
-  virtual void toJson(JsonDocument& json) = 0;
+  bool loop() {
+    loopBeforeValues();
+    const auto changed = loopValues();
+    if (changed) {
+      send();
+    }
+    return changed;
+  }
 
-  virtual bool isDue() = 0;
+  void send() {
+    JsonDocument json;
+    toJson(json.to<JsonObject>());
+    mqttPublish(String(name) + "/json", json);
+  }
 
-  virtual void markSent() = 0;
+  void toJson(const JsonObject& json) {
+    auto index = 0;
+    Value *value;
+    while ((value = getValue(index++)) != nullptr) {
+      value->toJson(json[value->getName()].to<JsonObject>());
+    }
+  }
+
+  virtual void loopBeforeValues() {}
+
+  virtual Value *getValue(int index) = 0;
+
+private:
+
+  bool loopValues() {
+    auto changed = false;
+    auto index = 0;
+    Value *value;
+    while ((value = getValue(index++)) != nullptr) {
+      if (value->loop()) {
+        changed = true;
+      }
+    }
+    return changed;
+  }
 
 };
 
diff --git a/src/patrix/sensor/Value.h b/src/patrix/sensor/Value.h
index b13a5fb..d31cd46 100644
--- a/src/patrix/sensor/Value.h
+++ b/src/patrix/sensor/Value.h
@@ -1,6 +1,9 @@
 #ifndef VALUE_H
 #define VALUE_H
+
+#include <WiFi.h>
 #include <patrix/log.h>
+#include <patrix/mqtt.h>
 
 class Value {
 
@@ -18,6 +21,8 @@ class Value {
 
   unsigned long currentMillis = 0;
 
+  time_t currentEpoch = 0;
+
   double sentValue = NAN;
 
   time_t sentInterval = 0;
@@ -41,22 +46,38 @@ public:
   void update(const double value) {
     currentValue = value;
     currentMillis = millis();
+    currentEpoch = time(nullptr);
   }
 
-  bool isDue() {
+  void toJson(const JsonObject& json) const {
+    json["value"] = currentValue;
+    json["time"] = currentEpoch;
+  }
+
+  void send() {
+    mqttPublish(String(parent) + "/" + name + "/plain", currentValue, true);
+
+    JsonDocument json;
+    toJson(json.to<JsonObject>());
+    mqttPublish(String(parent) + "/" + name + "/json", json);
+
+    markSent();
+  }
+
+  bool loop() {
     if (!isnan(currentValue) && millis() - currentMillis > maxAgeMillis) {
       warn("Value too old: %s/%s", parent, name);
       update(NAN);
     }
+
     const auto dueToNAN = isnan(currentValue) != isnan(sentValue);
     const auto dueToThreshold = abs(sentValue - currentValue) >= threshold;
     const auto dueToTime = sentInterval != 0 && sentInterval != time(nullptr) / overdueSeconds;
-    return dueToNAN || dueToThreshold || dueToTime;
-  }
-
-  void markSent() {
-    sentValue = currentValue;
-    sentInterval = time(nullptr) / overdueSeconds;
+    const auto changed = dueToNAN || dueToThreshold || dueToTime;
+    if (changed) {
+      send();
+    }
+    return changed;
   }
 
   const char *getName() const {
@@ -67,6 +88,17 @@ public:
     return currentValue;
   }
 
+  time_t getCurrentEpoch() const {
+    return currentEpoch;
+  }
+
+private:
+
+  void markSent() {
+    sentValue = currentValue;
+    sentInterval = time(nullptr) / overdueSeconds;
+  }
+
 };
 
 #endif