diff --git a/gateway/include/devices.h b/gateway/include/devices.h
index 6ae8b46..4a1451f 100644
--- a/gateway/include/devices.h
+++ b/gateway/include/devices.h
@@ -7,16 +7,20 @@
 using namespace Ha;
 
 DeviceConfig* gatewayDevice = (new DeviceConfig{MAIN_DEVICE_ID})->withName("RC Gateway")->withManufacturer("Adafruit")->withModel("Huzzah Esp8266");
-DeviceConfig* atTinyDevice = (new DeviceConfig{})->withManufacturer("Atmel")->withModel("AtTiny85")->withParent(gatewayDevice);
 
 struct OilTankRoomSensorBuilder {
     static Sensor* build(const char* id) {
-        auto device = (new DeviceConfig{*atTinyDevice})->withName("Oil tank room")->withArea("Basement");
-        device->id = id;
-        Sensor* sensor = (new Ha::TemperatureSensor(id))->asDevice(device);
-        (new VoltageSensor{sensor->id, "Battery voltage", "{{ value_json.sensor.diagnostic.voltage }}"})->ofDevice((id));
-        (new BatterySensor{sensor->id, "Battery level", "{{ ((states('sensor.oil_tank_room_battery_voltage')|float-2.5)|round(2)*100/2)|int }}"})->ofDevice(id);
-        return sensor;
+        auto device = (new DeviceConfig{ id })
+            ->withName("Oil tank room")
+            ->withManufacturer("Atmel")
+            ->withModel("AtTiny85")
+            ->withArea("Basement")
+            ->withParent(gatewayDevice);
+        return Builder<TemperatureSensor>::instance(id)
+            .asDevice(device)
+            .withDiagnostic(new VoltageSensor{id, "Battery voltage", "{{ value_json.sensor.diagnostic.voltage }}"})
+            .withDiagnostic(new BatterySensor{id, "Battery level", "{{ ((states('sensor.oil_tank_room_battery_voltage')|float-2.5)|round(2)*100/2)|int }}"})
+            .build();
     }
 };
 
@@ -45,13 +49,18 @@ struct OilTankLevelSensor : Sensor {
 
 struct OilSensorBuilder {
     static Sensor* build(const char* id) {
-        auto device = (new DeviceConfig{*atTinyDevice})->withName("Oil tank")->withArea("Basement");
-        device->id = id;
-        Sensor* sensor = (new OilTankSensor(id))->asDevice(device);
-        (new OilTankLevelSensor(sensor->id))->ofDevice(id);
-        (new VoltageSensor{id, "Battery voltage", "{{ value_json.sensor.diagnostic.voltage }}"})->ofDevice(id);
-        (new BatterySensor{id, "Battery level", "{{ ((states('sensor.oil_tank_battery_voltage')|float-3.6)|round(2)*100/1.6)|int }}"})->ofDevice(id);
-        return sensor;
+        auto device = (new DeviceConfig{ id })
+            ->withName("Oil tank")
+            ->withManufacturer("Arduino")
+            ->withModel("Pro Mini")
+            ->withArea("Basement")
+            ->withParent(gatewayDevice);
+        return Builder<OilTankSensor>::instance(id)
+            .asDevice(device)
+            .withSecondary(new OilTankLevelSensor(id))
+            .withDiagnostic(new VoltageSensor{id, "Battery voltage", "{{ value_json.sensor.diagnostic.voltage }}"})
+            .withDiagnostic(new BatterySensor{id, "Battery level", "{{ ((states('sensor.oil_tank_battery_voltage')|float-3.6)|round(2)*100/1.6)|int }}"})
+            .build();
     }
 };
 
@@ -61,7 +70,7 @@ struct PollinSwitch : Switch {
 
     PollinSwitch(const char* name, const char* group, const unsigned char channel, const char* area = nullptr)
         : Switch(name, Protocol_1::buildId(group, channel)), group(group), channel(channel) {
-        asDevice((new DeviceConfig{id})->withName(name)->withManufacturer("Pollin")->withArea(area)->withParent(gatewayDevice));
+        mainDevice = (new DeviceConfig{id})->withName(name)->withManufacturer("Pollin")->withArea(area)->withParent(gatewayDevice);
         p1Switches.insert({ string(id), this });
     }
 
@@ -80,7 +89,7 @@ struct EasyHomeSwitch : Switch {
         : Switch(name, id) {
         memcpy(&this->on[4], on, 4 * sizeof(unsigned long));
         memcpy(&this->off[4], off, 4 * sizeof(unsigned long));
-        asDevice((new DeviceConfig{id})->withName(name)->withManufacturer("Intertek")->withModel("Easy Home")->withArea(area)->withParent(gatewayDevice));
+        mainDevice = (new DeviceConfig{id})->withName(name)->withManufacturer("Intertek")->withModel("Easy Home")->withArea(area)->withParent(gatewayDevice);
         for (int i = 0; i < 8; i++) {
             onSwitches.insert({ this->on[i], this });
             offSwitches.insert({ this->off[i], this });
diff --git a/gateway/include/ha.h b/gateway/include/ha.h
index 61515cc..904f254 100644
--- a/gateway/include/ha.h
+++ b/gateway/include/ha.h
@@ -93,31 +93,56 @@ namespace Ha {
             jsonDoc["unique_id"] = uniqueId;
         }
     };
-
-    template <class T>
-    struct EntityConfig : Component {
-
-        EntityConfig(const char* name, const char* id, const char* type) : Component(name, id, type) {
-        }
-
-        T* asDevice(DeviceConfig* deviceConfig) {
-            mainDevice = deviceConfig;
-            return static_cast<T*>(this);
-        }
-
-        T* ofDevice(const char* id) {
-            mainDevice = new DeviceConfig{id};
-            return static_cast<T*>(this);
-        }
-    };
     
     List<Component> Component::components;
 
     template <class T>
-    struct Command : EntityConfig<T> {
+    struct Builder {
+        T* cmp;
+
+        Builder() {}
+        Builder(T* cmp) : cmp(cmp) {}
+        Builder(const char* id) {
+            cmp = new T{id};
+        }
+
+        static Builder& instance() {
+            return *(new Builder<T>());
+        }
+
+        static Builder& instance(T* c) {
+            return *(new Builder<T>(c));
+        }
+
+        static Builder& instance(const char* id) {
+            return *(new Builder<T>(id));
+        }
+
+        T* build() {
+            return static_cast<T*>(cmp);
+        }
+
+        Builder& withSecondary(Component* c) {
+            c->mainDevice = new DeviceConfig{ cmp->id };
+            return *this;
+        }
+
+        Builder& withDiagnostic(Component* c) {
+            c->entityCategory = "diagnostic";
+            c->mainDevice = new DeviceConfig{ cmp->id };
+            return *this;
+        }
+
+        Builder& asDevice(DeviceConfig* deviceConfig) {
+            cmp->mainDevice = deviceConfig;
+            return *this;
+        }
+    };
+
+    struct Command : Component {
         char commandTopic[TOPIC_SIZE];
 
-        Command(const char* name, const char* id, const char* type) : EntityConfig<T>(name, id, type) {
+        Command(const char* name, const char* id, const char* type) : Component(name, id, type) {
             sprintf(commandTopic, "homeassistant/%s/%s/%s", type, MAIN_DEVICE_ID, id);
         }
 
@@ -126,17 +151,17 @@ namespace Ha {
         }
 
         void buildConfig(JsonDocument& jsonDoc) override {
-            EntityConfig<T>::buildConfig(jsonDoc);
+            Component::buildConfig(jsonDoc);
             jsonDoc["command_topic"] = commandTopic;
         }
 
     };
 
     typedef void (*onMessage)(const char* msg);
-    struct Button : Command<Button> {
+    struct Button : Command {
         onMessage f;
 
-        Button(const char* name, const char* id, onMessage f) : Command(name, id, "button"), f(f) {}
+        Button(const char* name, const char* id, onMessage f = nullptr) : Command(name, id, "button"), f(f) {}
 
     };
 
@@ -150,7 +175,7 @@ namespace Ha {
         }
     };
 
-    struct Switch : Command<Switch>, StateConfig<Switch> {
+    struct Switch : Command, StateConfig<Switch> {
 
         virtual void onCommand(const char* msg){}
 
@@ -171,11 +196,15 @@ namespace Ha {
         }
     };
 
-    struct Sensor : EntityConfig<Sensor>, StateConfig<Sensor> {
+    struct Sensor : Component, StateConfig<Sensor> {
         const char* unitMeasure = nullptr;
         const char* valueTemplate = nullptr;
 
-        Sensor(const char* name, const char* id) : EntityConfig(name, Protocol_2::buildId(id), "sensor") {
+        Sensor() : Component(name, Protocol_2::buildId(id), "sensor") {
+            withStateTopic();
+        }
+
+        Sensor(const char* name, const char* id) : Component(name, Protocol_2::buildId(id), "sensor") {
             withStateTopic();
         }
 
@@ -184,7 +213,7 @@ namespace Ha {
         }
 
         void buildConfig(JsonDocument& jsonDoc) override {
-            EntityConfig::buildConfig(jsonDoc);
+            Component::buildConfig(jsonDoc);
             if (unitMeasure) jsonDoc["unit_of_measurement"] = unitMeasure;
             if (valueTemplate) jsonDoc["value_template"] = valueTemplate;
             jsonDoc["state_topic"] = stateTopic;
@@ -203,7 +232,6 @@ namespace Ha {
     struct VoltageSensor : Sensor {
         VoltageSensor(const char* id, const char* name, const char* valueTemplate) : Sensor(name, id) {
             this->valueTemplate = valueTemplate;
-            entityCategory = "diagnostic";
             deviceClass = "voltage";
             unitMeasure = "V";
         }
@@ -212,7 +240,6 @@ namespace Ha {
     struct BatterySensor : Sensor {
        BatterySensor(const char* id, const char* name, const char* valueTemplate) : Sensor(name, id) {
             this->valueTemplate = valueTemplate;
-            entityCategory = "diagnostic";
             deviceClass = "battery";
             unitMeasure = "%";
         }
diff --git a/gateway/include/mqtt.h b/gateway/include/mqtt.h
index 96957cb..998add7 100644
--- a/gateway/include/mqtt.h
+++ b/gateway/include/mqtt.h
@@ -31,12 +31,12 @@ namespace Mqtt {
         return client.publish(topic, 0, true, message);
     }
 
-    Ha::Button* buttons[] = {
-        (new Ha::Button{"Restart", "restart",
+    Button* buttons[] = {
+        Builder<Button>::instance(new Button{"Restart", "restart",
             [](const char* msg) {
                 if (String { "PRESS" }.equals(msg)) ESP.restart();
             }
-        })->asDevice(gatewayDevice)
+        }).asDevice(gatewayDevice).build()
     };
 
     Ha::Switch* switches[] = {