diff --git a/code/espurna/button.cpp b/code/espurna/button.cpp
index 35a2aebd..55601da1 100644
--- a/code/espurna/button.cpp
+++ b/code/espurna/button.cpp
@@ -3,6 +3,7 @@
 BUTTON MODULE
 
 Copyright (C) 2016-2019 by Xose Pérez <xose dot perez at gmail dot com>
+Copyright (C) 2019-2021 by Maxim Prokhorov <prokhorov dot max at outlook dot com>
 
 */
 
@@ -30,9 +31,7 @@ Copyright (C) 2016-2019 by Xose Pérez <xose dot perez at gmail dot com>
 
 #include "button_config.h"
 
-BrokerBind(ButtonBroker);
-
-// TODO: if we are using such conversion helpers across the codebase, should convert() be in internal ns?
+// -----------------------------------------------------------------------------
 
 namespace settings {
 namespace internal {
@@ -169,93 +168,77 @@ ButtonAction convert(const String& value) {
 
 // -----------------------------------------------------------------------------
 
-constexpr debounce_event::types::Config _buttonDecodeConfigBitmask(int bitmask) {
-    return {
-        ((bitmask & ButtonMask::Pushbutton)
-            ? debounce_event::types::Mode::Pushbutton
-            : debounce_event::types::Mode::Switch),
-        ((bitmask & ButtonMask::DefaultLow) ? debounce_event::types::PinValue::Low
-         : (bitmask & ButtonMask::DefaultHigh) ? debounce_event::types::PinValue::High
-         : (bitmask & ButtonMask::DefaultBoot) ? debounce_event::types::PinValue::Initial
-            : debounce_event::types::PinValue::Low),
-        ((bitmask & ButtonMask::SetPullup) ? debounce_event::types::PinMode::InputPullup
-            : (bitmask & ButtonMask::SetPulldown) ? debounce_event::types::PinMode::InputPulldown
-            : debounce_event::types::PinMode::Input)
-    };
-}
-
-constexpr ButtonAction _buttonDecodeEventAction(const ButtonActions& actions, button_event_t event) {
+constexpr ButtonAction _buttonDecodeEventAction(const ButtonActions& actions, ButtonEvent event) {
     return (
-        (event == button_event_t::Pressed) ? actions.pressed :
-        (event == button_event_t::Released) ? actions.released :
-        (event == button_event_t::Click) ? actions.click :
-        (event == button_event_t::DoubleClick) ? actions.dblclick :
-        (event == button_event_t::LongClick) ? actions.lngclick :
-        (event == button_event_t::LongLongClick) ? actions.lnglngclick :
-        (event == button_event_t::TripleClick) ? actions.trplclick : ButtonAction::None
+        (event == ButtonEvent::Pressed) ? actions.pressed :
+        (event == ButtonEvent::Released) ? actions.released :
+        (event == ButtonEvent::Click) ? actions.click :
+        (event == ButtonEvent::DoubleClick) ? actions.dblclick :
+        (event == ButtonEvent::LongClick) ? actions.lngclick :
+        (event == ButtonEvent::LongLongClick) ? actions.lnglngclick :
+        (event == ButtonEvent::TripleClick) ? actions.trplclick : ButtonAction::None
     );
 }
 
-constexpr button_event_t _buttonMapReleased(uint8_t count, unsigned long length, unsigned long lngclick_delay, unsigned long lnglngclick_delay) {
+constexpr ButtonEvent _buttonMapReleased(uint8_t count, unsigned long length, unsigned long lngclick_delay, unsigned long lnglngclick_delay) {
     return (
-        (0 == count) ? button_event_t::Released :
+        (0 == count) ? ButtonEvent::Released :
         (1 == count) ? (
-            (length > lnglngclick_delay) ? button_event_t::LongLongClick :
-            (length > lngclick_delay) ? button_event_t::LongClick : button_event_t::Click
+            (length > lnglngclick_delay) ? ButtonEvent::LongLongClick :
+            (length > lngclick_delay) ? ButtonEvent::LongClick : ButtonEvent::Click
         ) :
-        (2 == count) ? button_event_t::DoubleClick :
-        (3 == count) ? button_event_t::TripleClick :
-        button_event_t::None
+        (2 == count) ? ButtonEvent::DoubleClick :
+        (3 == count) ? ButtonEvent::TripleClick :
+        ButtonEvent::None
     );
 }
 
-ButtonActions _buttonConstructActions(unsigned char index) {
+ButtonActions _buttonConstructActions(size_t index) {
     return {
-        _buttonPress(index),
-        _buttonRelease(index),
-        _buttonClick(index),
-        _buttonDoubleClick(index),
-        _buttonLongClick(index),
-        _buttonLongLongClick(index),
-        _buttonTripleClick(index)
+        button::build::press(index),
+        button::build::release(index),
+        button::build::click(index),
+        button::build::doubleClick(index),
+        button::build::longClick(index),
+        button::build::longLongClick(index),
+        button::build::tripleClick(index)
     };
 }
 
-debounce_event::types::Config _buttonRuntimeConfig(unsigned char index) {
-    const auto config = _buttonDecodeConfigBitmask(_buttonConfigBitmask(index));
+debounce_event::types::Config _buttonRuntimeConfig(size_t index) {
     return {
-        getSetting({"btnMode", index}, config.mode),
-        getSetting({"btnDefVal", index}, config.default_value),
-        getSetting({"btnPinMode", index}, config.pin_mode)
+        getSetting({"btnMode", index}, button::build::mode(index)),
+        getSetting({"btnDefVal", index}, button::build::defaultValue(index)),
+        getSetting({"btnPinMode", index}, button::build::pinMode(index))
     };
 }
 
-int _buttonEventNumber(button_event_t event) {
+int _buttonEventNumber(ButtonEvent event) {
     return static_cast<int>(event);
 }
 
 // -----------------------------------------------------------------------------
 
-button_event_delays_t::button_event_delays_t() :
-    debounce(_buttonDebounceDelay()),
-    repeat(_buttonRepeatDelay()),
-    lngclick(_buttonLongClickDelay()),
-    lnglngclick(_buttonLongLongClickDelay())
+ButtonEventDelays::ButtonEventDelays() :
+    debounce(button::build::debounceDelay()),
+    repeat(button::build::repeatDelay()),
+    lngclick(button::build::longClickDelay()),
+    lnglngclick(button::build::longLongClickDelay())
 {}
 
-button_event_delays_t::button_event_delays_t(unsigned long debounce, unsigned long repeat, unsigned long lngclick, unsigned long lnglngclick) :
+ButtonEventDelays::ButtonEventDelays(unsigned long debounce, unsigned long repeat, unsigned long lngclick, unsigned long lnglngclick) :
     debounce(debounce),
     repeat(repeat),
     lngclick(lngclick),
     lnglngclick(lnglngclick)
 {}
 
-button_t::button_t(ButtonActions&& actions_, button_event_delays_t&& delays_) :
+button_t::button_t(ButtonActions&& actions_, ButtonEventDelays&& delays_) :
     actions(std::move(actions_)),
     event_delays(std::move(delays_))
 {}
 
-button_t::button_t(BasePinPtr&& pin, const debounce_event::types::Config& config, ButtonActions&& actions_, button_event_delays_t&& delays_) :
+button_t::button_t(BasePinPtr&& pin, const debounce_event::types::Config& config, ButtonActions&& actions_, ButtonEventDelays&& delays_) :
     event_emitter(std::make_unique<debounce_event::EventEmitter>(std::move(pin), config, delays_.debounce, delays_.repeat)),
     actions(std::move(actions_)),
     event_delays(std::move(delays_))
@@ -265,11 +248,11 @@ bool button_t::state() {
     return event_emitter->isPressed();
 }
 
-button_event_t button_t::loop() {
+ButtonEvent button_t::loop() {
     if (event_emitter) {
         switch (event_emitter->loop()) {
         case debounce_event::types::EventPressed:
-            return button_event_t::Pressed;
+            return ButtonEvent::Pressed;
         case debounce_event::types::EventReleased: {
             return _buttonMapReleased(
                 event_emitter->getEventCount(),
@@ -283,146 +266,118 @@ button_event_t button_t::loop() {
         }
     }
 
-    return button_event_t::None;
+    return ButtonEvent::None;
 }
 
 std::vector<button_t> _buttons;
 
 // -----------------------------------------------------------------------------
 
-unsigned char buttonCount() {
+size_t buttonCount() {
     return _buttons.size();
 }
 
 #if MQTT_SUPPORT
 
 std::bitset<ButtonsMax> _buttons_mqtt_send_all(
-    (1 == BUTTON_MQTT_SEND_ALL_EVENTS) ? 0xFFFFFFFFUL : 0UL
+    button::build::mqttSendAllEvents()
+    ? std::numeric_limits<unsigned long>::max()
+    : std::numeric_limits<unsigned long>::min()
 );
 std::bitset<ButtonsMax> _buttons_mqtt_retain(
-    (1 == BUTTON_MQTT_RETAIN) ? 0xFFFFFFFFUL : 0UL
+    button::build::mqttRetain()
+    ? std::numeric_limits<unsigned long>::max()
+    : std::numeric_limits<unsigned long>::min()
 );
 
 #endif
 
-#if WEB_SUPPORT
-
-void _buttonWebSocketOnVisible(JsonObject& root) {
-    if (buttonCount() > 0) {
-        root["btnVisible"] = 1;
-    }
-}
-
-void _buttonWebSocketOnConnected(JsonObject& root) {
-    root["btnRepDel"] = getSetting("btnRepDel", _buttonRepeatDelay());
-
-    // XXX: unused! pending webui changes
-
-#if 0
-    if (buttonCount() < 1) return;
-
-    JsonObject& module = root.createNestedObject("btn");
+// -----------------------------------------------------------------------------
 
-    // TODO: hardware can sometimes use a different providers
-    //       e.g. Sonoff Dual does not need `Pin`, `Mode` or any of `Del`
-    // TODO: schema names are uppercase to easily match settings?
-    // TODO: schema name->type map to generate WebUI elements?
+#if RELAY_SUPPORT
 
-    JsonArray& schema = module.createNestedArray("_schema");
+std::vector<unsigned char> _button_relays;
 
-    schema.add("Prov");
+size_t _buttonRelay(size_t id) {
+    return _button_relays[id];
+}
 
-    schema.add("GPIO");
-    schema.add("Mode");
-    schema.add("DefVal");
-    schema.add("PinMode");
+void _buttonRelayAction(size_t id, ButtonAction action) {
+    auto relayId = _buttonRelay(id);
 
-    schema.add("Press");
-    schema.add("Click");
-    schema.add("Dclk");
-    schema.add("Lclk");
-    schema.add("LLclk");
-    schema.add("Tclk");
+    switch (action) {
+    case ButtonAction::Toggle:
+        relayToggle(relayId);
+        break;
 
-    schema.add("DebDel");
-    schema.add("RepDel");
-    schema.add("LclkDel");
-    schema.add("LLclkDel");
+    case ButtonAction::On:
+        relayStatus(relayId, true);
+        break;
 
-#if RELAY_SUPPORT
-    schema.add("Relay");
-#endif
+    case ButtonAction::Off:
+        relayStatus(relayId, false);
+        break;
 
-#if MQTT_SUPPORT
-    schema.add("MqttSendAll");
-    schema.add("MqttRetain");
-#endif
+    case ButtonAction::Pulse:
+        // TODO
+        break;
 
-    JsonArray& buttons = module.createNestedArray("list");
+    default:
+        break;
+    }
+}
 
-    for (unsigned char i=0; i<buttonCount(); i++) {
-        JsonArray& button = buttons.createNestedArray();
+#endif // RELAY_SUPPORT
 
-        // TODO: configure PIN object instead of button specifically, link PIN<->BUTTON
-        button.add(getSetting({"btnProv", index}, _buttonProvider(index)));
-        if (_buttons[i].pin()) {
-            button.add(getSetting({"btnGPIO", index}, _buttonPin(index)));
-            const auto config = _buttonRuntimeConfig(index);
-            button.add(static_cast<int>(config.mode));
-            button.add(static_cast<int>(config.default_value));
-            button.add(static_cast<int>(config.pin_mode));
-        } else {
-            button.add(GPIO_NONE);
-            button.add(static_cast<int>(BUTTON_PUSHBUTTON));
-            button.add(0);
-            button.add(0);
-            button.add(0);
-        }
+// -----------------------------------------------------------------------------
 
-        button.add(_buttons[i].actions.pressed);
-        button.add(_buttons[i].actions.click);
-        button.add(_buttons[i].actions.dblclick);
-        button.add(_buttons[i].actions.lngclick);
-        button.add(_buttons[i].actions.lnglngclick);
-        button.add(_buttons[i].actions.trplclick);
+#if WEB_SUPPORT
 
-        button.add(_buttons[i].event_delays.debounce);
-        button.add(_buttons[i].event_delays.repeat);
-        button.add(_buttons[i].event_delays.lngclick);
-        button.add(_buttons[i].event_delays.lnglngclick);
+namespace {
 
-#if RELAY_SUPPORT
-        button.add(_buttons[i].relayID);
-#endif
+void _buttonWebSocketOnVisible(JsonObject& root) {
+    if (buttonCount()) {
+        root["btnVisible"] = 1;
+    }
+}
 
-        // TODO: send bitmask as number?
-#if MQTT_SUPPORT
-        button.add(_buttons_mqtt_send_all[i] ? 1 : 0);
-        button.add(_buttons_mqtt_retain[i] ? 1 : 0);
-#endif
+void _buttonWebSocketOnConnected(JsonObject& root) {
+    if (buttonCount()) {
+        root["btnRepDel"] = getSetting("btnRepDel", button::build::repeatDelay());
     }
-#endif
 }
 
 bool _buttonWebSocketOnKeyCheck(const char * key, JsonVariant&) {
     return (strncmp(key, "btn", 3) == 0);
 }
 
+} // namespace
+
 #endif // WEB_SUPPORT
 
-ButtonCustomAction _button_custom_action { nullptr };
+//------------------------------------------------------------------------------
+
+ButtonEventHandler _button_custom_action { nullptr };
 
-void buttonSetCustomAction(ButtonCustomAction action) {
-    _button_custom_action = action;
+void buttonSetCustomAction(ButtonEventHandler handler) {
+    _button_custom_action = handler;
 }
 
-bool buttonState(unsigned char id) {
+std::forward_list<ButtonEventHandler> _button_notify_event;
+
+void buttonSetEventNotify(ButtonEventHandler handler) {
+    _button_notify_event.push_front(handler);
+}
+
+//------------------------------------------------------------------------------
+
+bool buttonState(size_t id) {
     return (id < _buttons.size())
         ? _buttons[id].state()
         : false;
 }
 
-ButtonAction buttonAction(unsigned char id, const button_event_t event) {
+ButtonAction buttonAction(size_t id, ButtonEvent event) {
     return (id < _buttons.size())
         ? _buttonDecodeEventAction(_buttons[id].actions, event)
         : ButtonAction::None;
@@ -432,93 +387,53 @@ ButtonAction buttonAction(unsigned char id, const button_event_t event) {
 // (ref. https://github.com/esp8266/Arduino/pull/6950 "PROGMEM footprint cleanup for responseCodeToString")
 // In this particular case, saves 76 bytes (120 vs 44)
 
-String _buttonEventString(button_event_t event) {
+String _buttonEventString(ButtonEvent event) {
     const __FlashStringHelper* ptr = nullptr;
     switch (event) {
-        case button_event_t::Pressed:
-            ptr = F("pressed");
-            break;
-        case button_event_t::Released:
-            ptr = F("released");
-            break;
-        case button_event_t::Click:
-            ptr = F("click");
-            break;
-        case button_event_t::DoubleClick:
-            ptr = F("double-click");
-            break;
-        case button_event_t::LongClick:
-            ptr = F("long-click");
-            break;
-        case button_event_t::LongLongClick:
-            ptr = F("looong-click");
-            break;
-        case button_event_t::TripleClick:
-            ptr = F("triple-click");
-            break;
-        case button_event_t::None:
-            ptr = F("none");
-            break;
-    }
-    return String(ptr);
-}
-
-#if RELAY_SUPPORT
-
-unsigned char _buttonRelaySetting(unsigned char id) {
-    static std::vector<uint8_t> relays;
-
-    if (!relays.size()) {
-        relays.reserve(_buttons.size());
-        for (unsigned char button = 0; button < _buttons.size(); ++button) {
-            relays.push_back(getSetting({"btnRelay", button}, _buttonRelay(button)));
-        }
-    }
-
-    return relays[id];
-}
-
-void _buttonRelayAction(unsigned char id, ButtonAction action) {
-    auto relayId = _buttonRelaySetting(id);
-
-    switch (action) {
-    case ButtonAction::Toggle:
-        relayToggle(relayId);
+    case ButtonEvent::Pressed:
+        ptr = F("pressed");
         break;
-
-    case ButtonAction::On:
-        relayStatus(relayId, true);
+    case ButtonEvent::Released:
+        ptr = F("released");
         break;
-
-    case ButtonAction::Off:
-        relayStatus(relayId, false);
+    case ButtonEvent::Click:
+        ptr = F("click");
         break;
-
-    case ButtonAction::Pulse:
-        // TODO
+    case ButtonEvent::DoubleClick:
+        ptr = F("double-click");
         break;
-
-    default:
+    case ButtonEvent::LongClick:
+        ptr = F("long-click");
+        break;
+    case ButtonEvent::LongLongClick:
+        ptr = F("looong-click");
+        break;
+    case ButtonEvent::TripleClick:
+        ptr = F("triple-click");
+        break;
+    case ButtonEvent::None:
+        ptr = F("none");
         break;
     }
+    return String(ptr);
 }
 
-#endif // RELAY_SUPPORT
-
-void buttonEvent(unsigned char id, button_event_t event) {
+void buttonEvent(size_t id, ButtonEvent event) {
 
     DEBUG_MSG_P(PSTR("[BUTTON] Button #%u event %d (%s)\n"),
         id, _buttonEventNumber(event), _buttonEventString(event).c_str()
     );
-    if (event == button_event_t::None) return;
+
+    if (event == ButtonEvent::None) {
+        return;
+    }
 
     auto& button = _buttons[id];
 
     auto action = _buttonDecodeEventAction(button.actions, event);
-
-#if BROKER_SUPPORT
-    ButtonBroker::Publish(id, event);
-#endif
+    for (auto& notify : _button_notify_event) {
+        notify(id, event);
+    }
 
 #if MQTT_SUPPORT
     if ((action != ButtonAction::None) || _buttons_mqtt_send_all[id]) {
@@ -617,24 +532,54 @@ void buttonEvent(unsigned char id, button_event_t event) {
 }
 
 void _buttonConfigure() {
-    #if MQTT_SUPPORT
-        for (unsigned char index = 0; index < _buttons.size(); ++index) {
-            _buttons_mqtt_send_all[index] = getSetting({"btnMqttSendAll", index}, _buttonMqttSendAllEvents(index));
-            _buttons_mqtt_retain[index] = getSetting({"btnMqttRetain", index}, _buttonMqttRetain(index));
-        }
-    #endif
+    auto buttons = _buttons.size();
+
+#if RELAY_SUPPORT
+    _button_relays.clear();
+#endif
+
+    for (decltype(buttons) id = 0; id < buttons; ++id) {
+#if RELAY_SUPPORT
+        _button_relays.push_back(getSetting({"btnRelay", id}, button::build::relay(id)));
+#endif
+#if MQTT_SUPPORT
+        _buttons_mqtt_send_all[id] = getSetting({"btnMqttSendAll", id}, button::build::mqttSendAllEvents(id));
+        _buttons_mqtt_retain[id] = getSetting({"btnMqttRetain", id}, button::build::mqttRetain(id));
+#endif
+    }
 }
 
 // TODO: compatibility proxy, fetch global key before indexed
-template<typename T>
-unsigned long _buttonGetSetting(const char* key, unsigned char index, T default_value) {
-    return getSetting({key, index}, getSetting(key, default_value));
+unsigned long _buttonGetDelay(const char* key, size_t index, unsigned long default_value) {
+    unsigned long result { default_value };
+
+    bool found { false };
+    auto indexed = SettingsKey(key, index);
+    auto global = String(key);
+
+    settings::kv_store.foreach([&](settings::kvs_type::KeyValueResult&& kv) {
+        if (found) {
+            return;
+        }
+
+        if ((kv.key.length != indexed.length()) && (kv.key.length != global.length())) {
+            return;
+        }
+
+        auto other = kv.key.read();
+        found = indexed == other;
+        if (found || (global == other)) {
+            result = settings::internal::convert<unsigned long>(kv.value.read());
+        }
+    });
+
+    return result;
 }
 
 void buttonLoop() {
     for (size_t id = 0; id < _buttons.size(); ++id) {
         auto event = _buttons[id].loop();
-        if (event != button_event_t::None) {
+        if (event != ButtonEvent::None) {
             buttonEvent(id, event);
         }
     }
@@ -773,15 +718,15 @@ std::vector<AnalogPin*> AnalogPin::pins;
 
 #endif // BUTTON_PROVIDER_ANALOG_SUPPORT
 
-BasePinPtr _buttonGpioPin(unsigned char index, ButtonProvider provider) {
+BasePinPtr _buttonGpioPin(size_t index, ButtonProvider provider) {
     BasePinPtr result;
 
-    auto pin = getSetting({"btnGPIO", index}, _buttonPin(index));
+    auto pin = getSetting({"btnGpio", index}, button::build::pin(index));
 
     switch (provider) {
     case ButtonProvider::Gpio: {
 #if BUTTON_PROVIDER_GPIO_SUPPORT
-        auto* base = gpioBase(getSetting({"btnGPIOType", index}, _buttonPinType(index)));
+        auto* base = gpioBase(getSetting({"btnGpioType", index}, button::build::pinType(index)));
         if (!base) {
             break;
         }
@@ -801,7 +746,7 @@ BasePinPtr _buttonGpioPin(unsigned char index, ButtonProvider provider) {
             break;
         }
 
-        auto level = getSetting({"btnLevel", index}, _buttonAnalogLevel(index));
+        auto level = getSetting({"btnLevel", index}, button::build::analogLevel(index));
         if (!AnalogPin::checkExpectedLevel(level)) {
             break;
         }
@@ -818,30 +763,30 @@ BasePinPtr _buttonGpioPin(unsigned char index, ButtonProvider provider) {
     return result;
 }
 
-ButtonActions _buttonActions(unsigned char index) {
+ButtonActions _buttonActions(size_t index) {
     return {
-        getSetting({"btnPress", index}, _buttonPress(index)),
-        getSetting({"btnRlse", index}, _buttonRelease(index)),
-        getSetting({"btnClick", index}, _buttonClick(index)),
-        getSetting({"btnDclk", index}, _buttonDoubleClick(index)),
-        getSetting({"btnLclk", index}, _buttonLongClick(index)),
-        getSetting({"btnLLclk", index}, _buttonLongLongClick(index)),
-        getSetting({"btnTclk", index}, _buttonTripleClick(index))
+        getSetting({"btnPress", index}, button::build::press(index)),
+        getSetting({"btnRlse", index}, button::build::release(index)),
+        getSetting({"btnClick", index}, button::build::click(index)),
+        getSetting({"btnDclk", index}, button::build::doubleClick(index)),
+        getSetting({"btnLclk", index}, button::build::longClick(index)),
+        getSetting({"btnLLclk", index}, button::build::longLongClick(index)),
+        getSetting({"btnTclk", index}, button::build::tripleClick(index))
     };
 }
 
 // Note that we use settings without indexes as default values to preserve backwards compatibility
 
-button_event_delays_t _buttonDelays(unsigned char index) {
+ButtonEventDelays _buttonDelays(size_t index) {
     return {
-        _buttonGetSetting("btnDebDel", index, _buttonDebounceDelay(index)),
-        _buttonGetSetting("btnRepDel", index, _buttonRepeatDelay(index)),
-        _buttonGetSetting("btnLclkDel", index, _buttonLongClickDelay(index)),
-        _buttonGetSetting("btnLLclkDel", index, _buttonLongLongClickDelay(index)),
+        _buttonGetDelay("btnDebDel", index, button::build::debounceDelay(index)),
+        _buttonGetDelay("btnRepDel", index, button::build::repeatDelay(index)),
+        _buttonGetDelay("btnLclkDel", index, button::build::longClickDelay(index)),
+        _buttonGetDelay("btnLLclkDel", index, button::build::longLongClickDelay(index)),
     };
 }
 
-bool _buttonSetupProvider(unsigned char index, ButtonProvider provider) {
+bool _buttonSetupProvider(size_t index, ButtonProvider provider) {
     bool result { false };
 
     switch (provider) {
@@ -883,8 +828,8 @@ void _buttonSettingsMigrate(int version) {
 void buttonSetup() {
     _buttonSettingsMigrate(migrateVersion());
 
-    for (unsigned char index = 0; index < ButtonsMax; ++index) {
-        auto provider = getSetting({"btnProv", index}, _buttonProvider(index));
+    for (size_t index = 0; index < ButtonsMax; ++index) {
+        auto provider = getSetting({"btnProv", index}, button::build::provider(index));
         if (!_buttonSetupProvider(index, provider)) {
             break;
         }
@@ -892,9 +837,6 @@ void buttonSetup() {
 
     auto count = _buttons.size();
     DEBUG_MSG_P(PSTR("[BUTTON] Number of buttons: %u\n"), count);
-    if (!count) {
-        return;
-    }
 
 #if TERMINAL_SUPPORT
     terminalRegisterCommand(F("BUTTON"), [](const terminal::CommandContext& ctx) {
@@ -913,19 +855,19 @@ void buttonSetup() {
     });
 #endif
 
-    _buttonConfigure();
-
-    // Websocket Callbacks
-    #if WEB_SUPPORT
+    if (count) {
+#if WEB_SUPPORT
         wsRegister()
             .onVisible(_buttonWebSocketOnVisible)
             .onConnected(_buttonWebSocketOnConnected)
             .onKeyCheck(_buttonWebSocketOnKeyCheck);
-    #endif
+#endif
 
-    // Register system callbacks
-    espurnaRegisterLoop(buttonLoop);
-    espurnaRegisterReload(_buttonConfigure);
+        _buttonConfigure();
+        espurnaRegisterReload(_buttonConfigure);
+
+        espurnaRegisterLoop(buttonLoop);
+    }
 }
 
 #endif // BUTTON_SUPPORT
diff --git a/code/espurna/button.h b/code/espurna/button.h
index 3354b684..033dc0f5 100644
--- a/code/espurna/button.h
+++ b/code/espurna/button.h
@@ -10,8 +10,6 @@ Copyright (C) 2016-2019 by Xose Pérez <xose dot perez at gmail dot com>
 
 #include "espurna.h"
 
-#include "broker.h"
-
 #include "libs/BasePin.h"
 #include "libs/DebounceEvent.h"
 
@@ -28,7 +26,7 @@ enum class ButtonProvider : int {
     Analog
 };
 
-enum class button_event_t {
+enum class ButtonEvent {
     None,
     Pressed,
     Released,
@@ -71,9 +69,9 @@ struct ButtonActions {
     ButtonAction trplclick;
 };
 
-struct button_event_delays_t {
-    button_event_delays_t();
-    button_event_delays_t(unsigned long debounce, unsigned long repeat, unsigned long lngclick, unsigned long lnglngclick);
+struct ButtonEventDelays {
+    ButtonEventDelays();
+    ButtonEventDelays(unsigned long debounce, unsigned long repeat, unsigned long lngclick, unsigned long lnglngclick);
 
     unsigned long debounce;
     unsigned long repeat;
@@ -82,28 +80,27 @@ struct button_event_delays_t {
 };
 
 struct button_t {
-    button_t(ButtonActions&& actions, button_event_delays_t&& delays);
+    button_t(ButtonActions&& actions, ButtonEventDelays&& delays);
     button_t(BasePinPtr&& pin, const debounce_event::types::Config& config,
-        ButtonActions&& actions, button_event_delays_t&& delays);
+        ButtonActions&& actions, ButtonEventDelays&& delays);
 
     bool state();
-    button_event_t loop();
+    ButtonEvent loop();
 
     std::unique_ptr<debounce_event::EventEmitter> event_emitter;
 
     ButtonActions actions;
-    button_event_delays_t event_delays;
+    ButtonEventDelays event_delays;
 };
 
-BrokerDeclare(ButtonBroker, void(unsigned char id, button_event_t event));
-
-using ButtonCustomAction = void(*)(unsigned char id, button_event_t event);
-void buttonSetCustomAction(ButtonCustomAction);
+using ButtonEventHandler = void(*)(size_t id, ButtonEvent event);
+void buttonSetCustomAction(ButtonEventHandler);
+void buttonSetNotifyAction(ButtonEventHandler);
 
-bool buttonState(unsigned char id);
-ButtonAction buttonAction(unsigned char id, const button_event_t event);
+bool buttonState(size_t id);
+ButtonAction buttonAction(size_t id, const ButtonEvent event);
 
-void buttonEvent(unsigned char id, button_event_t event);
+void buttonEvent(size_t id, ButtonEvent event);
 
-unsigned char buttonCount();
+size_t buttonCount();
 void buttonSetup();
diff --git a/code/espurna/button_config.h b/code/espurna/button_config.h
index 096c7366..dd2feb63 100644
--- a/code/espurna/button_config.h
+++ b/code/espurna/button_config.h
@@ -20,7 +20,10 @@ constexpr int SetPulldown { 1 << 6 };
 
 } // namespace ButtonMask
 
-constexpr unsigned char _buttonPin(unsigned char index) {
+namespace button {
+namespace build {
+
+constexpr size_t pin(size_t index) {
     return (
         (index == 0) ? BUTTON1_PIN :
         (index == 1) ? BUTTON2_PIN :
@@ -33,7 +36,7 @@ constexpr unsigned char _buttonPin(unsigned char index) {
     );
 }
 
-constexpr GpioType _buttonPinType(unsigned char index) {
+constexpr GpioType pinType(size_t index) {
     return (
         (index == 0) ? BUTTON1_PIN_TYPE :
         (index == 1) ? BUTTON2_PIN_TYPE :
@@ -46,7 +49,7 @@ constexpr GpioType _buttonPinType(unsigned char index) {
     );
 }
 
-constexpr int _buttonConfigBitmask(unsigned char index) {
+constexpr int configBitmask(size_t index) {
     return (
         (index == 0) ? (BUTTON1_CONFIG) :
         (index == 1) ? (BUTTON2_CONFIG) :
@@ -59,7 +62,38 @@ constexpr int _buttonConfigBitmask(unsigned char index) {
     );
 }
 
-constexpr ButtonAction _buttonRelease(unsigned char index) {
+namespace internal {
+
+constexpr debounce_event::types::Config decode(int bitmask) {
+    return {
+        ((bitmask & ButtonMask::Pushbutton)
+            ? debounce_event::types::Mode::Pushbutton
+            : debounce_event::types::Mode::Switch),
+        ((bitmask & ButtonMask::DefaultLow) ? debounce_event::types::PinValue::Low
+         : (bitmask & ButtonMask::DefaultHigh) ? debounce_event::types::PinValue::High
+         : (bitmask & ButtonMask::DefaultBoot) ? debounce_event::types::PinValue::Initial
+            : debounce_event::types::PinValue::Low),
+        ((bitmask & ButtonMask::SetPullup) ? debounce_event::types::PinMode::InputPullup
+            : (bitmask & ButtonMask::SetPulldown) ? debounce_event::types::PinMode::InputPulldown
+            : debounce_event::types::PinMode::Input)
+    };
+}
+
+} // namespace internal
+
+constexpr debounce_event::types::Mode mode(size_t index) {
+    return internal::decode(configBitmask(index)).mode;
+}
+
+constexpr debounce_event::types::PinValue defaultValue(size_t index) {
+    return internal::decode(configBitmask(index)).default_value;
+}
+
+constexpr debounce_event::types::PinMode pinMode(size_t index) {
+    return internal::decode(configBitmask(index)).pin_mode;
+}
+
+constexpr ButtonAction release(size_t index) {
     return (
         (index == 0) ? BUTTON1_RELEASE :
         (index == 1) ? BUTTON2_RELEASE :
@@ -72,7 +106,7 @@ constexpr ButtonAction _buttonRelease(unsigned char index) {
     );
 }
 
-constexpr ButtonAction _buttonPress(unsigned char index) {
+constexpr ButtonAction press(size_t index) {
     return (
         (index == 0) ? BUTTON1_PRESS :
         (index == 1) ? BUTTON2_PRESS :
@@ -85,7 +119,7 @@ constexpr ButtonAction _buttonPress(unsigned char index) {
     );
 }
 
-constexpr ButtonAction _buttonClick(unsigned char index) {
+constexpr ButtonAction click(size_t index) {
     return (
         (index == 0) ? BUTTON1_CLICK :
         (index == 1) ? BUTTON2_CLICK :
@@ -98,7 +132,7 @@ constexpr ButtonAction _buttonClick(unsigned char index) {
     );
 }
 
-constexpr ButtonAction _buttonDoubleClick(unsigned char index) {
+constexpr ButtonAction doubleClick(size_t index) {
     return (
         (index == 0) ? BUTTON1_DBLCLICK :
         (index == 1) ? BUTTON2_DBLCLICK :
@@ -111,7 +145,7 @@ constexpr ButtonAction _buttonDoubleClick(unsigned char index) {
     );
 }
 
-constexpr ButtonAction _buttonTripleClick(unsigned char index) {
+constexpr ButtonAction tripleClick(size_t index) {
     return (
         (index == 0) ? BUTTON1_TRIPLECLICK :
         (index == 1) ? BUTTON2_TRIPLECLICK :
@@ -124,7 +158,7 @@ constexpr ButtonAction _buttonTripleClick(unsigned char index) {
     );
 }
 
-constexpr ButtonAction _buttonLongClick(unsigned char index) {
+constexpr ButtonAction longClick(size_t index) {
     return (
         (index == 0) ? BUTTON1_LNGCLICK :
         (index == 1) ? BUTTON2_LNGCLICK :
@@ -137,7 +171,7 @@ constexpr ButtonAction _buttonLongClick(unsigned char index) {
     );
 }
 
-constexpr ButtonAction _buttonLongLongClick(unsigned char index) {
+constexpr ButtonAction longLongClick(size_t index) {
     return (
         (index == 0) ? BUTTON1_LNGLNGCLICK :
         (index == 1) ? BUTTON2_LNGLNGCLICK :
@@ -150,7 +184,7 @@ constexpr ButtonAction _buttonLongLongClick(unsigned char index) {
     );
 }
 
-constexpr unsigned char _buttonRelay(unsigned char index) {
+constexpr size_t relay(size_t index) {
     return (
         (index == 0) ? (BUTTON1_RELAY - 1) :
         (index == 1) ? (BUTTON2_RELAY - 1) :
@@ -163,11 +197,11 @@ constexpr unsigned char _buttonRelay(unsigned char index) {
     );
 }
 
-constexpr unsigned long _buttonDebounceDelay() {
+constexpr unsigned long debounceDelay() {
     return BUTTON_DEBOUNCE_DELAY;
 }
 
-constexpr unsigned long _buttonDebounceDelay(unsigned char index) {
+constexpr unsigned long debounceDelay(size_t index) {
     return (
         (index == 0) ? BUTTON1_DEBOUNCE_DELAY :
         (index == 1) ? BUTTON2_DEBOUNCE_DELAY :
@@ -176,15 +210,15 @@ constexpr unsigned long _buttonDebounceDelay(unsigned char index) {
         (index == 4) ? BUTTON5_DEBOUNCE_DELAY :
         (index == 5) ? BUTTON6_DEBOUNCE_DELAY :
         (index == 6) ? BUTTON7_DEBOUNCE_DELAY :
-        (index == 7) ? BUTTON8_DEBOUNCE_DELAY : _buttonDebounceDelay()
+        (index == 7) ? BUTTON8_DEBOUNCE_DELAY : debounceDelay()
     );
 }
 
-constexpr unsigned long _buttonRepeatDelay() {
+constexpr unsigned long repeatDelay() {
     return BUTTON_REPEAT_DELAY;
 }
 
-constexpr unsigned long _buttonRepeatDelay(unsigned char index) {
+constexpr unsigned long repeatDelay(size_t index) {
     return (
         (index == 0) ? BUTTON1_REPEAT_DELAY :
         (index == 1) ? BUTTON2_REPEAT_DELAY :
@@ -193,15 +227,15 @@ constexpr unsigned long _buttonRepeatDelay(unsigned char index) {
         (index == 4) ? BUTTON5_REPEAT_DELAY :
         (index == 5) ? BUTTON6_REPEAT_DELAY :
         (index == 6) ? BUTTON7_REPEAT_DELAY :
-        (index == 7) ? BUTTON8_REPEAT_DELAY : _buttonRepeatDelay()
+        (index == 7) ? BUTTON8_REPEAT_DELAY : repeatDelay()
     );
 }
 
-constexpr unsigned long _buttonLongClickDelay() {
+constexpr unsigned long longClickDelay() {
     return BUTTON_LNGCLICK_DELAY;
 }
 
-constexpr unsigned long _buttonLongClickDelay(unsigned char index) {
+constexpr unsigned long longClickDelay(size_t index) {
     return (
         (index == 0) ? BUTTON1_LNGCLICK_DELAY :
         (index == 1) ? BUTTON2_LNGCLICK_DELAY :
@@ -210,15 +244,15 @@ constexpr unsigned long _buttonLongClickDelay(unsigned char index) {
         (index == 4) ? BUTTON5_LNGCLICK_DELAY :
         (index == 5) ? BUTTON6_LNGCLICK_DELAY :
         (index == 6) ? BUTTON7_LNGCLICK_DELAY :
-        (index == 7) ? BUTTON8_LNGCLICK_DELAY : _buttonLongClickDelay()
+        (index == 7) ? BUTTON8_LNGCLICK_DELAY : longClickDelay()
     );
 }
 
-constexpr unsigned long _buttonLongLongClickDelay() {
+constexpr unsigned long longLongClickDelay() {
     return BUTTON_LNGLNGCLICK_DELAY;
 }
 
-constexpr unsigned long _buttonLongLongClickDelay(unsigned char index) {
+constexpr unsigned long longLongClickDelay(size_t index) {
     return (
         (index == 0) ? BUTTON1_LNGLNGCLICK_DELAY :
         (index == 1) ? BUTTON2_LNGLNGCLICK_DELAY :
@@ -227,11 +261,15 @@ constexpr unsigned long _buttonLongLongClickDelay(unsigned char index) {
         (index == 4) ? BUTTON5_LNGLNGCLICK_DELAY :
         (index == 5) ? BUTTON6_LNGLNGCLICK_DELAY :
         (index == 6) ? BUTTON7_LNGLNGCLICK_DELAY :
-        (index == 7) ? BUTTON8_LNGLNGCLICK_DELAY : _buttonLongLongClickDelay()
+        (index == 7) ? BUTTON8_LNGLNGCLICK_DELAY : longLongClickDelay()
     );
 }
 
-constexpr bool _buttonMqttSendAllEvents(unsigned char index) {
+constexpr bool mqttSendAllEvents() {
+    return (1 == BUTTON_MQTT_SEND_ALL_EVENTS);
+}
+
+constexpr bool mqttSendAllEvents(size_t index) {
     return (
         (index == 0) ? (1 == BUTTON1_MQTT_SEND_ALL_EVENTS) :
         (index == 1) ? (1 == BUTTON2_MQTT_SEND_ALL_EVENTS) :
@@ -240,11 +278,15 @@ constexpr bool _buttonMqttSendAllEvents(unsigned char index) {
         (index == 4) ? (1 == BUTTON5_MQTT_SEND_ALL_EVENTS) :
         (index == 5) ? (1 == BUTTON6_MQTT_SEND_ALL_EVENTS) :
         (index == 6) ? (1 == BUTTON7_MQTT_SEND_ALL_EVENTS) :
-        (index == 7) ? (1 == BUTTON8_MQTT_SEND_ALL_EVENTS) : (1 == BUTTON_MQTT_SEND_ALL_EVENTS)
+        (index == 7) ? (1 == BUTTON8_MQTT_SEND_ALL_EVENTS) : mqttSendAllEvents()
     );
 }
 
-constexpr bool _buttonMqttRetain(unsigned char index) {
+constexpr bool mqttRetain() {
+    return (1 == BUTTON_MQTT_RETAIN);
+}
+
+constexpr bool mqttRetain(size_t index) {
     return (
         (index == 0) ? (1 == BUTTON1_MQTT_RETAIN) :
         (index == 1) ? (1 == BUTTON2_MQTT_RETAIN) :
@@ -253,11 +295,11 @@ constexpr bool _buttonMqttRetain(unsigned char index) {
         (index == 4) ? (1 == BUTTON5_MQTT_RETAIN) :
         (index == 5) ? (1 == BUTTON6_MQTT_RETAIN) :
         (index == 6) ? (1 == BUTTON7_MQTT_RETAIN) :
-        (index == 7) ? (1 == BUTTON8_MQTT_RETAIN) : (1 == BUTTON_MQTT_RETAIN)
+        (index == 7) ? (1 == BUTTON8_MQTT_RETAIN) : mqttRetain()
     );
 }
 
-constexpr ButtonProvider _buttonProvider(unsigned char index) {
+constexpr ButtonProvider provider(size_t index) {
     return (
         (index == 0) ? (BUTTON1_PROVIDER) :
         (index == 1) ? (BUTTON2_PROVIDER) :
@@ -270,7 +312,7 @@ constexpr ButtonProvider _buttonProvider(unsigned char index) {
     );
 }
 
-constexpr int _buttonAnalogLevel(unsigned char index) {
+constexpr int analogLevel(size_t index) {
     return (
         (index == 0) ? (BUTTON1_ANALOG_LEVEL) :
         (index == 1) ? (BUTTON2_ANALOG_LEVEL) :
@@ -282,3 +324,6 @@ constexpr int _buttonAnalogLevel(unsigned char index) {
         (index == 7) ? (BUTTON8_ANALOG_LEVEL) : 0
     );
 }
+
+} // namespace build
+} // namespace button
diff --git a/code/espurna/config/types.h b/code/espurna/config/types.h
index d2a5e4bd..7ea49fb8 100644
--- a/code/espurna/config/types.h
+++ b/code/espurna/config/types.h
@@ -199,16 +199,16 @@
 // LED
 //------------------------------------------------------------------------------
 
-#define LED_MODE_MANUAL             0       // LED will be managed manually (OFF by default)
-#define LED_MODE_WIFI               1       // LED will blink according to the WIFI status
-#define LED_MODE_FOLLOW             2       // LED will follow state of linked LED#_RELAY relay ID
-#define LED_MODE_FOLLOW_INVERSE     3       // LED will follow the opposite state of linked LED#_RELAY relay ID
-#define LED_MODE_FINDME             4       // LED will be ON if all relays are OFF
-#define LED_MODE_FINDME_WIFI        5       // A mixture between WIFI and FINDME
-#define LED_MODE_ON                 6       // LED always ON
-#define LED_MODE_OFF                7       // LED always OFF
-#define LED_MODE_RELAY              8       // If any relay is ON, LED will be ON, otherwise OFF
-#define LED_MODE_RELAY_WIFI         9       // A mixture between WIFI and RELAY, the reverse of MIXED
+#define LED_MODE_MANUAL             LedMode::Manual         // LED will be managed manually (OFF by default)
+#define LED_MODE_WIFI               LedMode::WiFi           // LED will blink according to the WIFI status
+#define LED_MODE_FOLLOW             LedMode::Follow         // LED will follow state of linked LED#_RELAY relay ID
+#define LED_MODE_FOLLOW_INVERSE     LedMode::FollowInverse  // LED will follow the opposite state of linked LED#_RELAY relay ID
+#define LED_MODE_FINDME             LedMode::FindMe         // LED will be ON if all relays are OFF
+#define LED_MODE_FINDME_WIFI        LedMode::FindMeWiFi     // A mixture between WIFI and FINDME
+#define LED_MODE_ON                 LedMode::On             // LED always ON
+#define LED_MODE_OFF                LedMode::Off            // LED always OFF
+#define LED_MODE_RELAY              LedMode::Relay          // If any relay is ON, LED will be ON, otherwise OFF
+#define LED_MODE_RELAY_WIFI         LedMode::RelayWiFi      // A mixture between WIFI and RELAY, the reverse of MIXED
 
 // -----------------------------------------------------------------------------
 // UI
diff --git a/code/espurna/led.cpp b/code/espurna/led.cpp
index 1f116ac7..f06ba733 100644
--- a/code/espurna/led.cpp
+++ b/code/espurna/led.cpp
@@ -3,6 +3,7 @@
 LED MODULE
 
 Copyright (C) 2016-2019 by Xose Pérez <xose dot perez at gmail dot com>
+Copyright (C) 2019-2021 by Maxim Prokhorov <prokhorov dot max at outlook dot com>
 
 */
 
@@ -20,25 +21,18 @@ Copyright (C) 2016-2019 by Xose Pérez <xose dot perez at gmail dot com>
 #include "led_pattern.h"
 #include "led_config.h"
 
-// LED helper class
-
-led_t::led_t(unsigned char pin_, bool inverse_, unsigned char mode_, unsigned char relayID_) :
-    pin(pin_),
-    inverse(inverse_),
-    mode(mode_),
-    relayID(relayID_)
-{
-    pinMode(pin, OUTPUT);
+void led_t::init() {
+    pinMode(_pin, OUTPUT);
     status(false);
 }
 
 bool led_t::status() {
-    bool result = digitalRead(pin);
-    return inverse ? !result : result;
+    bool result = digitalRead(_pin);
+    return _inverse ? !result : result;
 }
 
 bool led_t::status(bool new_status) {
-    digitalWrite(pin, inverse ? !new_status : new_status);
+    digitalWrite(_pin, _inverse ? !new_status : new_status);
     return new_status;
 }
 
@@ -46,50 +40,34 @@ bool led_t::toggle() {
     return status(!status());
 }
 
-led_delay_t::led_delay_t(unsigned long on_ms, unsigned long off_ms, unsigned char repeats) :
-    type(repeats ? led_delay_mode_t::Finite : led_delay_mode_t::Infinite),
-    on(microsecondsToClockCycles(on_ms * 1000)),
-    off(microsecondsToClockCycles(off_ms * 1000)),
-    repeats(repeats ? repeats : 0)
-{}
-
-led_delay_t::led_delay_t(unsigned long on_ms, unsigned long off_ms) :
-    led_delay_t(on_ms, off_ms, 0)
-{}
-
-led_pattern_t::led_pattern_t(const std::vector<led_delay_t>& delays) :
+LedPattern::LedPattern(const LedPattern::Delays& delays) :
     delays(delays),
     queue(),
     clock_last(ESP.getCycleCount()),
-    clock_delay(delays.size() ? delays.back().on : 0)
+    clock_delay(delays.size() ? delays.back().on() : 0)
 {}
 
-bool led_pattern_t::started() {
+bool LedPattern::started() {
     return queue.size() > 0;
 }
 
-bool led_pattern_t::ready() {
+bool LedPattern::ready() {
     return delays.size() > 0;
 }
 
-void led_pattern_t::start() {
+void LedPattern::start() {
     clock_last = ESP.getCycleCount();
     clock_delay = 0;
-    queue = {
-        delays.rbegin(), delays.rend()
-    };
+    queue = { delays.rbegin(), delays.rend() };
 }
 
-void led_pattern_t::stop() {
+void LedPattern::stop() {
     queue.clear();
 }
 
-// For relay-based modes
-bool _led_update = false;
-
 // For network-based modes, cycle ON & OFF (time in milliseconds)
 // XXX: internals convert these to clock cycles, delay cannot be longer than 25000 / 50000 ms
-const led_delay_t _ledDelays[] {
+static const LedDelay _ledDelays[] {
     {100, 100},   // Autoconfig
     {100, 4900},  // Connected
     {4900, 100},  // Connected (inverse)
@@ -98,30 +76,85 @@ const led_delay_t _ledDelays[] {
     {500, 500}    // Idle
 };
 
+enum class LedDelayName {
+    NetworkAutoconfig,
+    NetworkConnected,
+    NetworkConnectedInverse,
+    NetworkConfig,
+    NetworkConfigInverse,
+    NetworkIdle,
+    None
+};
+
+bool _led_update { false };
+
 std::vector<led_t> _leds;
 
 // -----------------------------------------------------------------------------
 
-unsigned char ledCount() {
+namespace settings {
+namespace internal {
+
+template <>
+LedMode convert(const String& value) {
+    if (value.length() == 1) {
+        switch (*value.c_str()) {
+        case '0':
+            return LedMode::Manual;
+        case '1':
+            return LedMode::WiFi;
+#if RELAY_SUPPORT
+        case '2':
+            return LedMode::Follow;
+        case '3':
+            return LedMode::FollowInverse;
+        case '4':
+            return LedMode::FindMe;
+        case '5':
+            return LedMode::FindMeWiFi;
+#endif
+        case '6':
+            return LedMode::On;
+        case '7':
+            return LedMode::Off;
+#if RELAY_SUPPORT
+        case '8':
+            return LedMode::Relay;
+        case '9':
+            return LedMode::RelayWiFi;
+#endif
+        }
+    }
+
+    return LedMode::Manual;
+}
+
+} // namespace internal
+} // namespace settings
+
+// -----------------------------------------------------------------------------
+
+size_t ledCount() {
     return _leds.size();
 }
 
 bool _ledStatus(led_t& led) {
-    return led.pattern.started() || led.status();
+    return led.started() || led.status();
 }
 
 bool _ledStatus(led_t& led, bool status) {
     bool result = false;
 
     // when led has pattern, status depends on whether it's running
-    if (led.pattern.ready()) {
+    auto& pattern = led.pattern();
+    if (pattern.ready()) {
         if (status) {
-            if (!led.pattern.started()) {
-                led.pattern.start();
+            if (!pattern.started()) {
+                pattern.start();
             }
             result = true;
         } else {
-            led.pattern.stop();
+            pattern.stop();
             led.status(false);
             result = false;
         }
@@ -137,63 +170,71 @@ bool _ledToggle(led_t& led) {
     return _ledStatus(led, !_ledStatus(led));
 }
 
-bool ledStatus(unsigned char id, bool status) {
-    if (id >= ledCount()) return false;
-    return _ledStatus(_leds[id], status);
+bool ledStatus(size_t id, bool status) {
+    if (id < ledCount()) {
+        return _ledStatus(_leds[id], status);
+    }
+
+    return status;
 }
 
-bool ledStatus(unsigned char id) {
-    if (id >= ledCount()) return false;
-    return _ledStatus(_leds[id]);
+bool ledStatus(size_t id) {
+    if (id < ledCount()) {
+        return _ledStatus(_leds[id]);
+    }
+
+    return false;
 }
 
-const led_delay_t& _ledModeToDelay(LedMode mode) {
+const LedDelay& _ledDelayFromName(LedDelayName pattern) {
     static_assert(
-        (sizeof(_ledDelays) / sizeof(_ledDelays[0])) <= static_cast<int>(LedMode::None),
-        "LedMode mapping out-of-bounds"
+        (sizeof(_ledDelays) / sizeof(_ledDelays[0])) <= static_cast<int>(LedDelayName::None),
+        "Out-of-bounds"
     );
-    return _ledDelays[static_cast<int>(mode)];
+    return _ledDelays[static_cast<int>(pattern)];
 }
 
 void _ledPattern(led_t& led) {
     const auto clock_current = ESP.getCycleCount();
-    if (clock_current - led.pattern.clock_last >= led.pattern.clock_delay) {
+
+    auto& pattern = led.pattern();
+    if (clock_current - pattern.clock_last >= pattern.clock_delay) {
         const bool status = led.toggle();
-        auto& current = led.pattern.queue.back();
-        switch (current.type) {
-            case led_delay_mode_t::Finite:
-                if (status && !--current.repeats) {
-                    led.pattern.queue.pop_back();
-                    if (!led.pattern.queue.size()) {
-                        led.status(false);
-                        return;
-                    }
+
+        auto& current = pattern.queue.back();
+        switch (current.mode()) {
+        case LedDelayMode::Finite:
+            if (status && current.repeat()) {
+                pattern.queue.pop_back();
+                if (!pattern.queue.size()) {
+                    led.status(false);
+                    return;
                 }
-                break;
-            case led_delay_mode_t::Infinite:
-            case led_delay_mode_t::None:
-            default:
-                break;
+            }
+            break;
+        case LedDelayMode::Infinite:
+        case LedDelayMode::None:
+            break;
         }
 
-        led.pattern.clock_delay = status ? current.on : current.off;
-        led.pattern.clock_last = ESP.getCycleCount();
+        pattern.clock_delay = status ? current.on() : current.off();
+        pattern.clock_last = ESP.getCycleCount();
     }
 }
 
-void _ledBlink(led_t& led, const led_delay_t& delays) {
+void _ledBlink(led_t& led, const LedDelay& delays) {
     static auto clock_last = ESP.getCycleCount();
-    static auto delay_for = delays.on;
+    static auto delay_for = delays.on();
 
     const auto clock_current = ESP.getCycleCount();
     if (clock_current - clock_last >= delay_for) {
-        delay_for = led.toggle() ? delays.on : delays.off;
+        delay_for = led.toggle() ? delays.on() : delays.off();
         clock_last = clock_current;
     }
 }
 
-inline void _ledBlink(led_t& led, const LedMode mode) {
-    _ledBlink(led, _ledModeToDelay(mode));
+inline void _ledBlink(led_t& led, LedDelayName name) {
+    _ledBlink(led, _ledDelayFromName(name));
 }
 
 #if WEB_SUPPORT
@@ -216,73 +257,87 @@ void _ledWebSocketOnConnected(JsonObject& root) {
     schema.add("GPIO");
     schema.add("Inv");
     schema.add("Mode");
+#if RELAY_SUPPORT
     schema.add("Relay");
+#endif
 
     JsonArray& leds = module.createNestedArray("list");
 
-    for (unsigned char index = 0; index < ledCount(); ++index) {
+    for (size_t index = 0; index < ledCount(); ++index) {
         JsonArray& led = leds.createNestedArray();
-        led.add(getSetting({"ledGPIO", index}, _ledPin(index)));
-        led.add(static_cast<int>(getSetting({"ledInv", index}, _ledInverse(index))));
-        led.add(getSetting({"ledMode", index}, _ledMode(index)));
-        led.add(getSetting({"ledRelay", index}, _ledRelay(index)));
+        led.add(getSetting({"ledGpio", index}, led::build::pin(index)));
+        led.add(static_cast<int>(getSetting({"ledInv", index}, led::build::inverse(index))));
+        led.add(static_cast<int>(getSetting({"ledMode", index}, led::build::mode(index))));
+#if RELAY_SUPPORT
+        led.add(getSetting({"ledRelay", index}, led::build::relay(index)));
+#endif
     }
 }
 
 #endif
 
 #if MQTT_SUPPORT
-void _ledMQTTCallback(unsigned int type, const char * topic, const char * payload) {
-
+void _ledMQTTCallback(unsigned int type, const char* topic, const char* payload) {
     if (type == MQTT_CONNECT_EVENT) {
         char buffer[strlen(MQTT_TOPIC_LED) + 3];
         snprintf_P(buffer, sizeof(buffer), PSTR("%s/+"), MQTT_TOPIC_LED);
         mqttSubscribe(buffer);
+        return;
     }
 
+    // Only want `led/+/<MQTT_SETTER>`
+    // We get the led ID from the `+`
     if (type == MQTT_MESSAGE_EVENT) {
-
-        // Only want `led/+/<MQTT_SETTER>`
         const String magnitude = mqttMagnitude((char *) topic);
-        if (!magnitude.startsWith(MQTT_TOPIC_LED)) return;
+        if (!magnitude.startsWith(MQTT_TOPIC_LED)) {
+            return;
+        }
 
-        // Get led ID from after the slash when t is `led/<LED_ID>`
-        unsigned int ledID = magnitude.substring(strlen(MQTT_TOPIC_LED) + 1).toInt();
-        if (ledID >= ledCount()) {
-            DEBUG_MSG_P(PSTR("[LED] Wrong ledID (%d)\n"), ledID);
+        size_t ledID;
+        if (!tryParseId(magnitude.substring(strlen(MQTT_TOPIC_LED) + 1).c_str(), ledCount, ledID)) {
             return;
         }
 
-        // Check if LED is managed
-        if (_leds[ledID].mode != LED_MODE_MANUAL) return;
+        auto& led = _leds[ledID];
+        if (led.mode() != LED_MODE_MANUAL) {
+            return;
+        }
 
-        // Get value based on rpc payload logic (see rpc.ino)
         const auto value = rpcParsePayload(payload);
         switch (value) {
-            case PayloadStatus::On:
-            case PayloadStatus::Off:
-                _ledStatus(_leds[ledID], (value == PayloadStatus::On));
-                break;
-            case PayloadStatus::Toggle:
-                _ledToggle(_leds[ledID]);
-                break;
-            case PayloadStatus::Unknown:
-            default:
-                _ledLoadPattern(_leds[ledID], payload);
-                _ledStatus(_leds[ledID], true);
-                break;
+        case PayloadStatus::On:
+        case PayloadStatus::Off:
+            _ledStatus(led, (value == PayloadStatus::On));
+            break;
+        case PayloadStatus::Toggle:
+            _ledToggle(led);
+            break;
+        case PayloadStatus::Unknown:
+        default:
+            _ledLoadPattern(led, payload);
+            _ledStatus(led, true);
+            break;
         }
-
     }
-
 }
+
+#endif
+
+#if RELAY_SUPPORT
+std::vector<size_t> _led_relays;
 #endif
 
 void _ledConfigure() {
-    for (unsigned char id = 0; id < _leds.size(); ++id) {
-        _leds[id].mode = getSetting({"ledMode", id}, _ledMode(id));
-        _leds[id].relayID = getSetting({"ledRelay", id}, _ledRelay(id));
-        _leds[id].pattern.stop();
+#if RELAY_SUPPORT
+    _led_relays.resize(relayCount(), RelaysMax);
+#endif
+
+    for (size_t id = 0; id < _leds.size(); ++id) {
+#if RELAY_SUPPORT
+        _led_relays[id] = getSetting({"ledRelay", id}, led::build::relay(id));
+#endif
+        _leds[id].mode(getSetting({"ledMode", id}, led::build::mode(id)));
+        _leds[id].stop();
         _ledLoadPattern(_leds[id], getSetting({"ledPattern", id}).c_str());
     }
     _led_update = true;
@@ -295,21 +350,25 @@ void ledUpdate(bool do_update) {
 }
 
 void ledLoop() {
-
     const auto wifi_state = wifiState();
 
-    for (auto& led : _leds) {
+    for (size_t id = 0; id < _leds.size(); ++id) {
+        auto& led = _leds[id];
+
+        switch (led.mode()) {
+
+            case LED_MODE_MANUAL:
+                break;
 
-        switch (led.mode) {
             case LED_MODE_WIFI:
                 if ((wifi_state & WIFI_STATE_WPS) || (wifi_state & WIFI_STATE_SMARTCONFIG)) {
-                    _ledBlink(led, LedMode::NetworkAutoconfig);
+                    _ledBlink(led, LedDelayName::NetworkAutoconfig);
                 } else if (wifi_state & WIFI_STATE_STA) {
-                    _ledBlink(led, LedMode::NetworkConnected);
+                    _ledBlink(led, LedDelayName::NetworkConnected);
                 } else if (wifi_state & WIFI_STATE_AP) {
-                    _ledBlink(led, LedMode::NetworkConfig);
+                    _ledBlink(led, LedDelayName::NetworkConfig);
                 } else {
-                    _ledBlink(led, LedMode::NetworkIdle);
+                    _ledBlink(led, LedDelayName::NetworkIdle);
                 }
                 break;
 
@@ -317,60 +376,60 @@ void ledLoop() {
 
             case LED_MODE_FINDME_WIFI:
                 if ((wifi_state & WIFI_STATE_WPS) || (wifi_state & WIFI_STATE_SMARTCONFIG)) {
-                    _ledBlink(led, LedMode::NetworkAutoconfig);
+                    _ledBlink(led, LedDelayName::NetworkAutoconfig);
                 } else if (wifi_state & WIFI_STATE_STA) {
-                    if (relayStatus(led.relayID)) {
-                        _ledBlink(led, LedMode::NetworkConnected);
+                    if (relayStatus(_led_relays[id])) {
+                        _ledBlink(led, LedDelayName::NetworkConnected);
                     } else {
-                        _ledBlink(led, LedMode::NetworkConnectedInverse);
+                        _ledBlink(led, LedDelayName::NetworkConnectedInverse);
                     }
                 } else if (wifi_state & WIFI_STATE_AP) {
-                    if (relayStatus(led.relayID)) {
-                        _ledBlink(led, LedMode::NetworkConfig);
+                    if (relayStatus(_led_relays[id])) {
+                        _ledBlink(led, LedDelayName::NetworkConfig);
                     } else {
-                        _ledBlink(led, LedMode::NetworkConfigInverse);
+                        _ledBlink(led, LedDelayName::NetworkConfigInverse);
                     }
                 } else {
-                    _ledBlink(led, LedMode::NetworkIdle);
+                    _ledBlink(led, LedDelayName::NetworkIdle);
                 }
                 break;
 
             case LED_MODE_RELAY_WIFI:
                 if ((wifi_state & WIFI_STATE_WPS) || (wifi_state & WIFI_STATE_SMARTCONFIG)) {
-                    _ledBlink(led, LedMode::NetworkAutoconfig);
+                    _ledBlink(led, LedDelayName::NetworkAutoconfig);
                 } else if (wifi_state & WIFI_STATE_STA) {
-                    if (relayStatus(led.relayID)) {
-                        _ledBlink(led, LedMode::NetworkConnected);
+                    if (relayStatus(_led_relays[id])) {
+                        _ledBlink(led, LedDelayName::NetworkConnected);
                     } else {
-                        _ledBlink(led, LedMode::NetworkConnectedInverse);
+                        _ledBlink(led, LedDelayName::NetworkConnectedInverse);
                     }
                 } else if (wifi_state & WIFI_STATE_AP) {
-                    if (relayStatus(led.relayID)) {
-                        _ledBlink(led, LedMode::NetworkConfig);
+                    if (relayStatus(_led_relays[id])) {
+                        _ledBlink(led, LedDelayName::NetworkConfig);
                     } else {
-                        _ledBlink(led, LedMode::NetworkConfigInverse);
+                        _ledBlink(led, LedDelayName::NetworkConfigInverse);
                     }
                 } else {
-                    _ledBlink(led, LedMode::NetworkIdle);
+                    _ledBlink(led, LedDelayName::NetworkIdle);
                 }
                 break;
 
             case LED_MODE_FOLLOW:
                 if (!_led_update) break;
-                _ledStatus(led, relayStatus(led.relayID));
+                _ledStatus(led, relayStatus(_led_relays[id]));
                 break;
 
             case LED_MODE_FOLLOW_INVERSE:
                 if (!_led_update) break;
-                led.status(!relayStatus(led.relayID));
-                _ledStatus(led, !relayStatus(led.relayID));
+                led.status(!relayStatus(_led_relays[id]));
+                _ledStatus(led, !relayStatus(_led_relays[id]));
                 break;
 
             case LED_MODE_FINDME: {
                 if (!_led_update) break;
                 bool status = true;
-                for (unsigned char relayID = 0; relayID < relayCount(); ++relayID) {
-                    if (relayStatus(relayID)) {
+                for (size_t relayId = 0; relayId < relayCount(); ++relayId) {
+                    if (relayStatus(relayId)) {
                         status = false;
                         break;
                     }
@@ -382,8 +441,8 @@ void ledLoop() {
             case LED_MODE_RELAY: {
                 if (!_led_update) break;
                 bool status = false;
-                for (unsigned char relayID = 0; relayID < relayCount(); ++relayID) {
-                    if (relayStatus(relayID)) {
+                for (size_t relayId = 0; relayId < relayCount(); ++relayId) {
+                    if (relayStatus(relayId)) {
                         status = true;
                         break;
                     }
@@ -406,7 +465,7 @@ void ledLoop() {
 
         }
 
-        if (led.pattern.started()) {
+        if (led.started()) {
             _ledPattern(led);
             continue;
         }
@@ -430,75 +489,45 @@ void _ledSettingsMigrate(int version) {
 
 void ledSetup() {
     _ledSettingsMigrate(migrateVersion());
+    _leds.reserve(led::build::preconfiguredLeds());
 
-    size_t leds = 0;
-
-    #if LED1_PIN != GPIO_NONE
-        ++leds;
-    #endif
-    #if LED2_PIN != GPIO_NONE
-        ++leds;
-    #endif
-    #if LED3_PIN != GPIO_NONE
-        ++leds;
-    #endif
-    #if LED4_PIN != GPIO_NONE
-        ++leds;
-    #endif
-    #if LED5_PIN != GPIO_NONE
-        ++leds;
-    #endif
-    #if LED6_PIN != GPIO_NONE
-        ++leds;
-    #endif
-    #if LED7_PIN != GPIO_NONE
-        ++leds;
-    #endif
-    #if LED8_PIN != GPIO_NONE
-        ++leds;
-    #endif
-
-    _leds.reserve(leds);
-
-    for (unsigned char index=0; index < LedsMax; ++index) {
-        const auto pin = getSetting({"ledGPIO", index}, _ledPin(index));
+    for (size_t index = 0; index < LedsMax; ++index) {
+        const auto pin = getSetting({"ledGpio", index}, led::build::pin(index));
         if (!gpioLock(pin)) {
             break;
         }
 
-        _leds.emplace_back(
-            pin,
-            getSetting({"ledInv", index}, _ledInverse(index)),
-            getSetting({"ledMode", index}, _ledMode(index)),
-            getSetting({"ledRelay", index}, _ledRelay(index))
-        );
+        _leds.emplace_back(pin,
+            getSetting({"ledInv", index}, led::build::inverse(index)),
+            getSetting({"ledMode", index}, led::build::mode(index)));
     }
 
-    _led_update = true;
+    auto leds = _leds.size();
+
+    DEBUG_MSG_P(PSTR("[LED] Number of leds: %u\n"), leds);
+    if (leds) {
+        _ledConfigure();
 
-    #if MQTT_SUPPORT
+#if MQTT_SUPPORT
         mqttRegister(_ledMQTTCallback);
-    #endif
+#endif
 
-    #if WEB_SUPPORT
+#if WEB_SUPPORT
         wsRegister()
             .onVisible(_ledWebSocketOnVisible)
             .onConnected(_ledWebSocketOnConnected)
             .onKeyCheck(_ledWebSocketOnKeyCheck);
-    #endif
+#endif
 
-    #if RELAY_SUPPORT
+#if RELAY_SUPPORT
         relaySetStatusNotify([](size_t, bool) {
             ledUpdate(true);
         });
-    #endif
-
-    DEBUG_MSG_P(PSTR("[LED] Number of leds: %d\n"), _leds.size());
-
-    // Main callbacks
-    espurnaRegisterLoop(ledLoop);
-    espurnaRegisterReload(_ledConfigure);
+#endif
 
+        espurnaRegisterLoop(ledLoop);
+        espurnaRegisterReload(_ledConfigure);
+    }
 }
 
 
diff --git a/code/espurna/led.h b/code/espurna/led.h
index 5acf38ae..6da0ebf6 100644
--- a/code/espurna/led.h
+++ b/code/espurna/led.h
@@ -12,38 +12,77 @@ Copyright (C) 2016-2019 by Xose Pérez <xose dot perez at gmail dot com>
 
 #include <vector>
 
-constexpr size_t LedsMax = 8;
+constexpr size_t LedsMax { 8ul };
 
 enum class LedMode {
-    NetworkAutoconfig,
-    NetworkConnected,
-    NetworkConnectedInverse,
-    NetworkConfig,
-    NetworkConfigInverse,
-    NetworkIdle,
-    None
+    Manual,
+    WiFi,
+    Follow,
+    FollowInverse,
+    FindMe,
+    FindMeWiFi,
+    On,
+    Off,
+    Relay,
+    RelayWiFi
 };
 
-enum class led_delay_mode_t {
+enum class LedDelayMode {
     Finite,
     Infinite,
     None
 };
 
-struct led_delay_t {
-    led_delay_t() = delete;
-    led_delay_t(unsigned long on_ms, unsigned long off_ms);
-    led_delay_t(unsigned long on_ms, unsigned long off_ms, unsigned char repeats);
-
-    led_delay_mode_t type;
-    unsigned long on;
-    unsigned long off;
-    unsigned char repeats;
+struct LedDelay {
+    LedDelay() = delete;
+
+    constexpr LedDelay(unsigned long on_ms, unsigned long off_ms, unsigned char repeats) :
+        _mode(repeats ? LedDelayMode::Finite : LedDelayMode::Infinite),
+        _on(microsecondsToClockCycles(on_ms * 1000)),
+        _off(microsecondsToClockCycles(off_ms * 1000)),
+        _repeats(repeats)
+    {}
+
+    constexpr LedDelay(unsigned long on_ms, unsigned long off_ms) :
+        LedDelay(on_ms, off_ms, 0)
+    {}
+
+    LedDelayMode mode() const {
+        return _mode;
+    }
+
+    unsigned long on() const {
+        return _on;
+    }
+
+    unsigned long off() const {
+        return _off;
+    }
+
+    unsigned char repeats() const {
+        return _repeats;
+    }
+
+    bool repeat() {
+        if (_repeats) {
+            --_repeats;
+        }
+
+        return _repeats;
+    }
+
+private:
+    LedDelayMode _mode;
+    unsigned long _on;
+    unsigned long _off;
+    unsigned char _repeats;
 };
 
-struct led_pattern_t {
-    led_pattern_t() = default;
-    led_pattern_t(const std::vector<led_delay_t>& delays);
+struct LedPattern {
+    using Delays = std::vector<LedDelay>;
+
+    LedPattern() = default;
+    LedPattern(const Delays& delays);
 
     void start();
     void stop();
@@ -51,32 +90,71 @@ struct led_pattern_t {
     bool started();
     bool ready();
 
-    std::vector<led_delay_t> delays;
-    std::vector<led_delay_t> queue;
+    Delays delays;
+    Delays queue;
     unsigned long clock_last;
     unsigned long clock_delay;
 };
 
 struct led_t {
     led_t() = delete;
-    led_t(unsigned char pin, bool inverse, unsigned char mode, unsigned char relayID);
+    led_t(unsigned char pin, bool inverse, LedMode mode) :
+        _pin(pin),
+        _inverse(inverse),
+        _mode(mode)
+    {
+        init();
+    }
+
+    unsigned char pin() const {
+        return _pin;
+    }
+
+    LedMode mode() const {
+        return _mode;
+    }
+
+    void mode(LedMode mode) {
+        _mode = mode;
+    }
+
+    bool inverse() const {
+        return _inverse;
+    }
+
+    LedPattern& pattern() {
+        return _pattern;
+    }
+
+    void init();
+
+    void start() {
+        _pattern.stop();
+    }
+
+    bool started() {
+        return _pattern.started();
+    }
+
+    void stop() {
+        _pattern.stop();
+    }
 
     bool status();
     bool status(bool new_status);
 
     bool toggle();
 
-    unsigned char pin;
-    bool inverse;
-    unsigned char mode;
-    unsigned char relayID;
-
-    led_pattern_t pattern;
+private:
+    unsigned char _pin;
+    bool _inverse;
+    LedMode _mode;
+    LedPattern _pattern;
 };
 
+size_t ledCount();
+
 void ledUpdate(bool do_update);
-unsigned char ledCount();
-bool ledStatus(unsigned char id, bool status);
-bool ledStatus(unsigned char id);
+bool ledStatus(size_t id, bool status);
+bool ledStatus(size_t id);
 void ledSetup();
-
diff --git a/code/espurna/led_config.h b/code/espurna/led_config.h
index b8df5caf..cd521f07 100644
--- a/code/espurna/led_config.h
+++ b/code/espurna/led_config.h
@@ -8,7 +8,39 @@ LED MODULE
 
 #include "espurna.h"
 
-constexpr const unsigned char _ledPin(unsigned char index) {
+namespace led {
+namespace build {
+
+constexpr size_t preconfiguredLeds() {
+    return 0ul
+    #if LED1_PIN != GPIO_NONE
+        + 1ul
+    #endif
+    #if LED2_PIN != GPIO_NONE
+        + 1ul
+    #endif
+    #if LED3_PIN != GPIO_NONE
+        + 1ul
+    #endif
+    #if LED4_PIN != GPIO_NONE
+        + 1ul
+    #endif
+    #if LED5_PIN != GPIO_NONE
+        + 1ul
+    #endif
+    #if LED6_PIN != GPIO_NONE
+        + 1ul
+    #endif
+    #if LED7_PIN != GPIO_NONE
+        + 1ul
+    #endif
+    #if LED8_PIN != GPIO_NONE
+        + 1ul
+    #endif
+        ;
+}
+
+constexpr unsigned char pin(size_t index) {
     return (
         (index == 0) ? LED1_PIN :
         (index == 1) ? LED2_PIN :
@@ -21,7 +53,7 @@ constexpr const unsigned char _ledPin(unsigned char index) {
     );
 }
 
-constexpr const unsigned char _ledMode(unsigned char index) {
+constexpr LedMode mode(size_t index) {
     return (
         (index == 0) ? LED1_MODE :
         (index == 1) ? LED2_MODE :
@@ -30,11 +62,11 @@ constexpr const unsigned char _ledMode(unsigned char index) {
         (index == 4) ? LED5_MODE :
         (index == 5) ? LED6_MODE :
         (index == 6) ? LED7_MODE :
-        (index == 7) ? LED8_MODE : LED_MODE_WIFI
+        (index == 7) ? LED8_MODE : LedMode::Manual
     );
 }
 
-constexpr const unsigned char _ledRelay(unsigned char index) {
+constexpr unsigned char relay(size_t index) {
     return (
         (index == 0) ? (LED1_RELAY - 1) :
         (index == 1) ? (LED2_RELAY - 1) :
@@ -47,7 +79,7 @@ constexpr const unsigned char _ledRelay(unsigned char index) {
     );
 }
 
-constexpr const bool _ledInverse(unsigned char index) {
+constexpr bool inverse(size_t index) {
     return (
         (index == 0) ? (1 == LED1_PIN_INVERSE) :
         (index == 1) ? (1 == LED2_PIN_INVERSE) :
@@ -59,3 +91,6 @@ constexpr const bool _ledInverse(unsigned char index) {
         (index == 7) ? (1 == LED8_PIN_INVERSE) : false
     );
 }
+
+} // namespace build
+} // namespace led
diff --git a/code/espurna/led_pattern.h b/code/espurna/led_pattern.h
index 8ec5b66e..dfb4377b 100644
--- a/code/espurna/led_pattern.h
+++ b/code/espurna/led_pattern.h
@@ -16,7 +16,7 @@ Copyright (C) 2020 by Maxim Prokhorov <prokhorov dot max at outlook dot com>
 
 // Scans input string with format
 // '<on1>,<off1>,<repeats1> <on2>,<off2>,<repeats2> ...'
-// Directly changing `led.pattern.delays` contents
+// Directly changing `LedPattern::delays` contents
 
 void _ledLoadPattern(led_t& led, const char* input) {
     char buffer[16];
@@ -28,7 +28,8 @@ void _ledLoadPattern(led_t& led, const char* input) {
     const char* p = input;
     const char* marker;
 
-    led.pattern.delays.clear();
+    auto& pattern = led.pattern();
+    pattern.delays.clear();
 
 loop:
 const char *yyt1;const char *yyt2;const char *yyt3;
@@ -153,9 +154,7 @@ yy17:
             buffer[int(p - d3)] = '\0';
             repeats = strtoul(buffer, nullptr, 10);
 
-            led.pattern.delays.emplace_back(
-                on, off, repeats
-            );
+            pattern.delays.emplace_back(on, off, repeats);
 
             goto loop;
         }
diff --git a/code/espurna/led_pattern.h.in b/code/espurna/led_pattern.h.in
index 7d5bf8f2..5b562b3b 100644
--- a/code/espurna/led_pattern.h.in
+++ b/code/espurna/led_pattern.h.in
@@ -26,7 +26,8 @@ void _ledLoadPattern(led_t& led, const char* input) {
     const char* p = input;
     const char* marker;
 
-    led.pattern.delays.clear();
+    auto& pattern = led.pattern;
+    pattern.delays.clear();
 
 loop:
 /*!stags:re2c format = 'const char *@@;'; */
@@ -61,9 +62,7 @@ loop:
             buffer[int(p - d3)] = '\0';
             repeats = strtoul(buffer, nullptr, 10);
 
-            led.pattern.delays.emplace_back(
-                on, off, repeats
-            );
+            pattern.delays.emplace_back(on, off, repeats);
 
             goto loop;
         }
diff --git a/code/espurna/light.cpp b/code/espurna/light.cpp
index fab1dfd0..c3ff380c 100644
--- a/code/espurna/light.cpp
+++ b/code/espurna/light.cpp
@@ -75,7 +75,7 @@ constexpr long Hsv::ValueMax;
 class LightChannelProvider : public RelayProviderBase {
 public:
     LightChannelProvider() = delete;
-    explicit LightChannelProvider(unsigned char id) :
+    explicit LightChannelProvider(size_t id) :
         _id(id)
     {}
 
@@ -90,7 +90,7 @@ public:
     }
 
 private:
-    unsigned char _id { RELAY_NONE };
+    size_t _id { RelaysMax };
 };
 
 class LightGlobalProvider : public RelayProviderBase {
@@ -382,8 +382,8 @@ my92xx_model_t convert(const String& value) {
 
 #endif
 
-bool _setValue(unsigned char, unsigned int) __attribute__((warn_unused_result));
-bool _setValue(unsigned char id, unsigned int value) {
+bool _setValue(size_t, unsigned int) __attribute__((warn_unused_result));
+bool _setValue(size_t id, unsigned int value) {
     if (_light_channels[id].value != value) {
         _light_channels[id].value = value;
         return true;
@@ -392,7 +392,7 @@ bool _setValue(unsigned char id, unsigned int value) {
     return false;
 }
 
-void _setInputValue(unsigned char id, long value) {
+void _setInputValue(size_t id, long value) {
     _light_channels[id].inputValue = std::clamp(value, Light::ValueMin, Light::ValueMax);
 }
 
@@ -408,7 +408,7 @@ bool _lightApplyBrightnessChannels(size_t channels) {
     channels = std::min(channels, lightChannels());
     OnceFlag changed;
 
-    for (unsigned char channel = 0; channel < lightChannels(); ++channel) {
+    for (size_t channel = 0; channel < lightChannels(); ++channel) {
         if (channel >= channels) {
             scale = 1.0f;
         }
@@ -468,32 +468,33 @@ bool _lightApplyBrightnessColor() {
     // Scale up to equal input values. So [250,150,50] -> [200,100,0,50] -> [250, 125, 0, 63]
     unsigned char max_in = std::max({_light_channels[0].inputValue, _light_channels[1].inputValue, _light_channels[2].inputValue});
     unsigned char max_out = std::max({_light_channels[0].value, _light_channels[1].value, _light_channels[2].value, _light_channels[3].value});
-    unsigned char channelSize = _light_use_cct ? 5 : 4;
+
+    size_t channelSize = _light_use_cct ? 5 : 4;
 
     if (_light_use_cct) {
         max_out = std::max(max_out, _light_channels[4].value);
     }
 
     double factor = (max_out > 0) ? (double) (max_in / max_out) : 0;
-    for (unsigned char i=0; i < channelSize; i++) {
+    for (size_t i = 0; i < channelSize; ++i) {
         changed = _setValue(i, lround((double) _light_channels[i].value * factor * brightness));
     }
 
     // Scale white channel to match brightness
-    for (unsigned char i=3; i < channelSize; i++) {
+    for (size_t i = 3; i < channelSize; ++i) {
         changed = _setValue(i, constrain(static_cast<unsigned int>(_light_channels[i].value * LIGHT_WHITE_FACTOR), Light::BrightnessMin, Light::BrightnessMax));
     }
 
     // For the rest of channels, don't apply brightness, it is already in the inputValue
     // i should be 4 when RGBW and 5 when RGBWW
-    for (unsigned char i=channelSize; i < _light_channels.size(); i++) {
+    for (size_t i = channelSize; i < _light_channels.size(); ++i) {
         changed = _setValue(i, _light_channels[i].inputValue);
     }
 
     return changed.get();
 }
 
-char _lightTag(size_t channels, unsigned char index) {
+char _lightTag(size_t channels, size_t index) {
     constexpr size_t Columns { 5ul };
     constexpr size_t Rows { 5ul };
 
@@ -513,12 +514,12 @@ char _lightTag(size_t channels, unsigned char index) {
     return 0;
 }
 
-char _lightTag(unsigned char index) {
+char _lightTag(size_t index) {
     return _lightTag(_light_channels.size(), index);
 }
 
 // UI hint about channel distribution
-const char* _lightDesc(size_t channels, unsigned char index) {
+const char* _lightDesc(size_t channels, size_t index) {
     const __FlashStringHelper* ptr { F("UNKNOWN") };
     switch (_lightTag(channels, index)) {
     case 'W':
@@ -541,7 +542,7 @@ const char* _lightDesc(size_t channels, unsigned char index) {
     return reinterpret_cast<const char*>(ptr);
 }
 
-const char* _lightDesc(unsigned char index) {
+const char* _lightDesc(size_t index) {
     return _lightDesc(_light_channels.size(), index);
 }
 
@@ -827,11 +828,11 @@ void _lightAdjustBrightness(const String& payload) {
     _lightAdjustBrightness(payload.c_str());
 }
 
-void _lightAdjustChannel(unsigned char id, const char* payload) {
+void _lightAdjustChannel(size_t id, const char* payload) {
     lightChannel(id, _lightAdjustValue(lightChannel(id), payload));
 }
 
-void _lightAdjustChannel(unsigned char id, const String& payload) {
+void _lightAdjustChannel(size_t id, const String& payload) {
     _lightAdjustChannel(id, payload.c_str());
 }
 
@@ -967,7 +968,7 @@ public:
             state(_state);
         }
 
-        for (unsigned char index = 0; index < _transitions.size(); ++index) {
+        for (size_t index = 0; index < _transitions.size(); ++index) {
             auto& transition = _transitions[index];
             if (!transition.count) {
                 continue;
@@ -1118,7 +1119,7 @@ inline bool _lightPwmMap(long value, long& result) {
 }
 
 // both require original values to be scaled into a PWM frequency
-void _lightProviderHandleValue(unsigned char channel, float value) {
+void _lightProviderHandleValue(size_t channel, float value) {
     long pwm;
     if (!_lightPwmMap(std::lround(value), pwm)) {
         return;
@@ -1145,7 +1146,7 @@ void _lightProviderHandleState(bool state) {
     _light_provider->state(state);
 }
 
-void _lightProviderHandleValue(unsigned char channel, float value) {
+void _lightProviderHandleValue(size_t channel, float value) {
     _light_provider->channel(channel, value);
 }
 
@@ -1281,7 +1282,7 @@ void lightSave(bool save) {
 
 void _lightSaveRtcmem() {
     auto channels = LightRtcmem::defaultChannels();
-    for (unsigned char channel = 0; channel < lightChannels(); ++channel) {
+    for (size_t channel = 0; channel < lightChannels(); ++channel) {
         channels[channel] = _light_channels[channel].inputValue;
     }
 
@@ -1294,7 +1295,7 @@ void _lightRestoreRtcmem() {
     LightRtcmem light(value);
 
     auto& channels = light.channels();
-    for (unsigned char channel = 0; channel < lightChannels(); ++channel) {
+    for (size_t channel = 0; channel < lightChannels(); ++channel) {
         _light_channels[channel].inputValue = channels[channel];
     }
 
@@ -1307,7 +1308,7 @@ void _lightSaveSettings() {
         return;
     }
 
-    for (unsigned char channel = 0; channel < lightChannels(); ++channel) {
+    for (size_t channel = 0; channel < lightChannels(); ++channel) {
         setSetting({"ch", channel}, _light_channels[channel].inputValue);
     }
 
@@ -1318,7 +1319,7 @@ void _lightSaveSettings() {
 }
 
 void _lightRestoreSettings() {
-    for (unsigned char channel = 0; channel < lightChannels(); ++channel) {
+    for (size_t channel = 0; channel < lightChannels(); ++channel) {
         auto value = getSetting({"ch", channel}, (channel == 0) ? Light::ValueMax : Light::ValueMin);
         _light_channels[channel].inputValue = value;
     }
@@ -1349,16 +1350,8 @@ bool _lightParsePayload(const String& payload) {
     return _lightParsePayload(payload.c_str());
 }
 
-bool _lightTryParseChannel(const char* p, unsigned char& id) {
-    char* endp { nullptr };
-    const unsigned long result { strtoul(p, &endp, 10) };
-    if ((endp == p) || (*endp != '\0') || (result >= lightChannels())) {
-        DEBUG_MSG_P(PSTR("[LIGHT] Invalid channelID (%s)\n"), p);
-        return false;
-    }
-
-    id = result;
-    return true;
+bool _lightTryParseChannel(const char* p, size_t& id) {
+    return tryParseId(p, lightChannels, id);
 }
 
 // -----------------------------------------------------------------------------
@@ -1485,7 +1478,7 @@ void _lightMqttCallback(unsigned int type, const char * topic, const char * payl
 
         // Channel
         if (t.startsWith(MQTT_TOPIC_CHANNEL)) {
-            unsigned char id;
+            size_t id;
             if (!_lightTryParseChannel(t.c_str() + strlen(MQTT_TOPIC_CHANNEL) + 1, id)) {
                 return;
             }
@@ -1561,7 +1554,7 @@ void lightMQTTGroup() {
 template <typename T>
 bool _lightApiTryHandle(ApiRequest& request, T&& callback) {
     auto id_param = request.wildcard(0);
-    unsigned char id;
+    size_t id;
     if (!_lightTryParseChannel(id_param.c_str(), id)) {
         return false;
     }
@@ -1659,13 +1652,13 @@ void _lightApiSetup() {
 
     apiRegister(F(MQTT_TOPIC_CHANNEL "/+"),
         [](ApiRequest& request) {
-            return _lightApiTryHandle(request, [&](unsigned char id) {
+            return _lightApiTryHandle(request, [&](size_t id) {
                 request.send(String(static_cast<int>(_light_channels[id].target)));
                 return true;
             });
         },
         [](ApiRequest& request) {
-            return _lightApiTryHandle(request, [&](unsigned char id) {
+            return _lightApiTryHandle(request, [&](size_t id) {
                 _lightAdjustChannel(id, request.param(F("value")));
                 lightUpdate();
                 return true;
@@ -1716,7 +1709,7 @@ void _lightWebSocketStatus(JsonObject& root) {
         root["useCCT"] = _light_use_cct;
     }
     JsonArray& channels = root.createNestedArray("channels");
-    for (unsigned char id=0; id < _light_channels.size(); id++) {
+    for (size_t id = 0; id < _light_channels.size(); ++id) {
         channels.add(lightChannel(id));
     }
     root["brightness"] = lightBrightness();
@@ -1813,29 +1806,26 @@ void _lightInitCommands() {
             return;
         }
 
-        auto id = -1;
-        if (ctx.argc > 1) {
-            id = ctx.argv[1].toInt();
-        }
-
-        auto description = [&](unsigned char channel) {
-            ctx.output.printf("#%hhu (%s): %hhu\n", channel, _lightDesc(channels, channel), _light_channels[channel].inputValue);
+        auto description = [&](size_t channel) {
+            ctx.output.printf("#%u (%s): %hhu\n", channel, _lightDesc(channels, channel), _light_channels[channel].inputValue);
         };
 
-        if (id < 0 || id >= static_cast<decltype(id)>(channels)) {
-            for (unsigned char index = 0; index < channels; ++index) {
-                description(index);
+        if (ctx.argc > 2) {
+            size_t id;
+            if (!_lightTryParseChannel(ctx.argv[1].c_str(), id)) {
+                terminalError(ctx, F("Invalid channel ID"));
+                return;
             }
-            terminalOK(ctx);
-            return;
-        }
 
-        if (ctx.argc > 2) {
             _lightAdjustChannel(id, ctx.argv[2].c_str());
             lightUpdate();
+            description(id);
+        } else {
+            for (size_t index = 0; index < channels; ++index) {
+                description(index);
+            }
         }
 
-        description(id);
         terminalOK(ctx);
     });
 
@@ -2116,17 +2106,19 @@ void lightUpdate() {
     lightUpdate(lightTransition());
 }
 
-void lightState(unsigned char id, bool state) {
-    if (id >= _light_channels.size()) return;
-    if (_light_channels[id].state != state) {
+void lightState(size_t id, bool state) {
+    if ((id < _light_channels.size()) && _light_channels[id].state != state) {
         _light_channels[id].state = state;
         _light_state_changed = true;
     }
 }
 
-bool lightState(unsigned char id) {
-    if (id >= _light_channels.size()) return false;
-    return _light_channels[id].state;
+bool lightState(size_t id) {
+    if (id < _light_channels.size()) {
+        return _light_channels[id].state;
+    }
+
+    return false;
 }
 
 void lightState(bool state) {
@@ -2232,18 +2224,22 @@ Light::MiredsRange lightMiredsRange() {
     return { _light_cold_mireds, _light_warm_mireds };
 }
 
-long lightChannel(unsigned char id) {
-    if (id >= _light_channels.size()) return 0;
-    return _light_channels[id].inputValue;
+long lightChannel(size_t id) {
+    if (id < _light_channels.size()) {
+        return _light_channels[id].inputValue;
+    }
+
+    return 0l;
 }
 
-void lightChannel(unsigned char id, long value) {
-    if (id >= _light_channels.size()) return;
-    _setInputValue(id, value);
+void lightChannel(size_t id, long value) {
+    if (id < _light_channels.size()) {
+        _setInputValue(id, value);
+    }
 }
 
-void lightChannelStep(unsigned char id, long steps, long multiplier) {
-    lightChannel(id, static_cast<int>(lightChannel(id)) + (steps * multiplier));
+void lightChannelStep(size_t id, long steps, long multiplier) {
+    lightChannel(id, lightChannel(id) + (steps * multiplier));
 }
 
 long lightBrightness() {
@@ -2316,7 +2312,7 @@ const unsigned long _light_iofunc[16] PROGMEM = {
 
 namespace {
 
-inline bool _lightUseGamma(size_t channels, unsigned char index) {
+inline bool _lightUseGamma(size_t channels, size_t index) {
     switch (_lightTag(channels, index)) {
     case 'R':
     case 'G':
@@ -2327,7 +2323,7 @@ inline bool _lightUseGamma(size_t channels, unsigned char index) {
     return false;
 }
 
-inline bool _lightUseGamma(unsigned char index) {
+inline bool _lightUseGamma(size_t index) {
     return _lightUseGamma(_light_channels.size(), index);
 }
 
@@ -2376,7 +2372,7 @@ void _lightConfigure() {
     _light_transition_step = getSetting("ltStep", LIGHT_TRANSITION_STEP);
 
     _light_use_gamma = getSetting("useGamma", 1 == LIGHT_USE_GAMMA);
-    for (unsigned char index = 0; index < lightChannels(); ++index) {
+    for (size_t index = 0; index < lightChannels(); ++index) {
 #if LIGHT_PROVIDER == LIGHT_PROVIDER_MY92XX
         _light_my92xx_channel_map[index] = getSetting({"ltMy92xxCh", index}, Light::build::my92xxChannel(index));
 #endif
@@ -2535,7 +2531,7 @@ void lightSetup() {
             getSetting("ltMy92xxDiGPIO", Light::build::my92xxDiPin()),
             getSetting("ltMy92xxDckiGPIO", Light::build::my92xxDckiPin()),
             Light::build::my92xxCommand());
-        for (unsigned char index = 0; index < channels; ++index) {
+        for (size_t index = 0; index < channels; ++index) {
             _light_channels.emplace_back(GPIO_NONE);
         }
     }
@@ -2547,7 +2543,7 @@ void lightSetup() {
         // 3-tuples of MUX_REGISTER, MUX_VALUE and GPIO number
         uint32_t io_info[Light::ChannelsMax][3];
 
-        for (unsigned char index = 0; index < Light::ChannelsMax; ++index) {
+        for (size_t index = 0; index < Light::ChannelsMax; ++index) {
 
             // Load up until first GPIO_NONE. Allow settings to override, but not remove values
             const auto pin = getSetting({"ltDimmerGPIO", index}, Light::build::channelPin(index));
diff --git a/code/espurna/light.h b/code/espurna/light.h
index 953520e2..7d49bb6b 100644
--- a/code/espurna/light.h
+++ b/code/espurna/light.h
@@ -164,7 +164,7 @@ class LightProvider {
 public:
     virtual void update() = 0;
     virtual void state(bool) = 0;
-    virtual void channel(unsigned char ch, float value) = 0;
+    virtual void channel(size_t ch, float value) = 0;
 };
 
 struct LightTransition {
@@ -221,8 +221,8 @@ long lightColdWhite();
 void lightWarmWhite(long value);
 long lightWarmWhite();
 
-void lightState(unsigned char i, bool state);
-bool lightState(unsigned char i);
+void lightState(size_t id, bool state);
+bool lightState(size_t id);
 
 void lightState(bool state);
 bool lightState();
@@ -230,11 +230,11 @@ bool lightState();
 void lightBrightness(long brightness);
 long lightBrightness();
 
-long lightChannel(unsigned char id);
-void lightChannel(unsigned char id, long value);
+long lightChannel(size_t id);
+void lightChannel(size_t id, long value);
 
 void lightBrightnessStep(long steps, long multiplier = LIGHT_STEP);
-void lightChannelStep(unsigned char id, long steps, long multiplier = LIGHT_STEP);
+void lightChannelStep(size_t id, long steps, long multiplier = LIGHT_STEP);
 
 void lightUpdate(bool save, LightTransition transition, Light::Report report);
 void lightUpdate(bool save, LightTransition transition, int report);
diff --git a/code/espurna/light_config.h b/code/espurna/light_config.h
index 0d435385..d327ac8c 100644
--- a/code/espurna/light_config.h
+++ b/code/espurna/light_config.h
@@ -15,7 +15,7 @@ constexpr unsigned char enablePin() {
     return LIGHT_ENABLE_PIN;
 }
 
-constexpr unsigned char channelPin(unsigned char index) {
+constexpr unsigned char channelPin(size_t index) {
     return (
         (index == 0) ? LIGHT_CH1_PIN :
         (index == 1) ? LIGHT_CH2_PIN :
@@ -25,7 +25,7 @@ constexpr unsigned char channelPin(unsigned char index) {
     );
 }
 
-constexpr bool inverse(unsigned char index) {
+constexpr bool inverse(size_t index) {
     return (
         (index == 0) ? (1 == LIGHT_CH1_INVERSE) :
         (index == 1) ? (1 == LIGHT_CH2_INVERSE) :
@@ -41,7 +41,7 @@ constexpr my92xx_cmd_t my92xxCommand() {
     return MY92XX_COMMAND;
 }
 
-constexpr unsigned char my92xxChannels() {
+constexpr size_t my92xxChannels() {
     return MY92XX_CHANNELS;
 }
 
@@ -67,15 +67,15 @@ constexpr unsigned char _my92xx_mapping[MY92XX_CHANNELS] {
     MY92XX_MAPPING
 };
 
-constexpr unsigned char my92xxChannel(unsigned char)
+constexpr unsigned char my92xxChannel(size_t)
     __attribute__((deprecated("MY92XX_CH# flags should be used instead of MY92XX_MAPPING")));
-constexpr unsigned char my92xxChannel(unsigned char channel) {
+constexpr unsigned char my92xxChannel(size_t channel) {
     return _my92xx_mapping[channel];
 }
 
 #else
 
-constexpr unsigned char my92xxChannel(unsigned char channel) {
+constexpr unsigned char my92xxChannel(size_t channel) {
     return (channel == 0) ? MY92XX_CH1 :
         (channel == 1) ? MY92XX_CH2 :
         (channel == 2) ? MY92XX_CH3 :
diff --git a/code/espurna/relay.cpp b/code/espurna/relay.cpp
index ecb20cf0..3416aea2 100644
--- a/code/espurna/relay.cpp
+++ b/code/espurna/relay.cpp
@@ -62,7 +62,7 @@ struct RelayMaskHelper {
         _mask.reset();
     }
 
-    void set(unsigned char id, bool status) {
+    void set(size_t id, bool status) {
         _mask.set(id, status);
     }
 
@@ -255,8 +255,8 @@ std::vector<relay_t> _relays;
 bool _relayRecursive { false };
 size_t _relayDummy { 0ul };
 
-unsigned long _relay_flood_window { _relayFloodWindowMs() };
-unsigned long _relay_flood_changes { _relayFloodChanges() };
+unsigned long _relay_flood_window { relay::build::floodWindowMs() };
+unsigned long _relay_flood_changes { relay::build::floodChanges() };
 
 unsigned long _relay_delay_interlock;
 int _relay_sync_mode { RELAY_SYNC_ANY };
@@ -337,7 +337,7 @@ RelayProviderBase* _relayDummyProvider() {
 // Real GPIO provider, using BasePin interface to implement writers
 
 struct GpioProvider : public RelayProviderBase {
-    GpioProvider(unsigned char id, RelayType type, std::unique_ptr<BasePin>&& pin, std::unique_ptr<BasePin>&& reset_pin) :
+    GpioProvider(size_t id, RelayType type, std::unique_ptr<BasePin>&& pin, std::unique_ptr<BasePin>&& reset_pin) :
         _id(id),
         _type(type),
         _pin(std::move(pin)),
@@ -397,7 +397,7 @@ struct GpioProvider : public RelayProviderBase {
     }
 
 private:
-    unsigned char _id { RelaysMax };
+    size_t _id { RelaysMax };
     RelayType _type { RelayType::Normal };
     std::unique_ptr<BasePin> _pin;
     std::unique_ptr<BasePin> _reset_pin;
@@ -410,7 +410,7 @@ private:
 class DualProvider : public RelayProviderBase {
 public:
     DualProvider() = delete;
-    explicit DualProvider(unsigned char id) : _id(id) {
+    explicit DualProvider(size_t id) : _id(id) {
         _instances.push_back(this);
     }
 
@@ -444,7 +444,7 @@ public:
         }
     }
 
-    unsigned char relayId() const {
+    size_t relayId() const {
         return _id;
     }
 
@@ -465,7 +465,7 @@ public:
     static void flush() {
         bool sync { true };
         RelayMaskHelper mask;
-        for (unsigned char index = 0; index < _instances.size(); ++index) {
+        for (size_t index = 0; index < _instances.size(); ++index) {
             bool status { relayStatus(_instances[index]->relayId()) };
             sync = sync && status;
             mask.set(index, status);
@@ -505,13 +505,13 @@ public:
         }
 
         // Then, manage relays individually
-        for (unsigned char index = 0; index < _instances.size(); ++index) {
+        for (size_t index = 0; index < _instances.size(); ++index) {
             relayStatus(_instances[index]->relayId(), mask[index]);
         }
     }
 
 private:
-    unsigned char _id { 0 };
+    size_t _id;
 
     static std::vector<DualProvider*> _instances;
 };
@@ -527,7 +527,7 @@ std::vector<DualProvider*> DualProvider::_instances;
 class StmProvider : public RelayProviderBase {
 public:
     StmProvider() = delete;
-    explicit StmProvider(unsigned char id) :
+    explicit StmProvider(size_t id) :
         _id(id)
     {}
 
@@ -564,7 +564,7 @@ public:
     }
 
 private:
-    unsigned char _id;
+    size_t _id;
 };
 
 #endif // RELAY_PROVIDER_STM_SUPPORT
@@ -573,18 +573,11 @@ private:
 // UTILITY
 // -----------------------------------------------------------------------------
 
-bool _relayTryParseId(const char* p, unsigned char& relayID) {
-    char* endp { nullptr };
-    const unsigned long result { strtoul(p, &endp, 10) };
-    if ((endp == p) || (*endp != '\0') || (result >= relayCount())) {
-        return false;
-    }
-
-    relayID = result;
-    return true;
+bool _relayTryParseId(const char* p, size_t& id) {
+    return tryParseId(p, relayCount, id);
 }
 
-bool _relayTryParseIdFromPath(const String& endpoint, unsigned char& relayID) {
+bool _relayTryParseIdFromPath(const String& endpoint, size_t& id) {
     int next_slash { endpoint.lastIndexOf('/') };
     if (next_slash < 0) {
         return false;
@@ -596,10 +589,10 @@ bool _relayTryParseIdFromPath(const String& endpoint, unsigned char& relayID) {
         return false;
     }
 
-    return _relayTryParseId(p, relayID);
+    return _relayTryParseId(p, id);
 }
 
-void _relayHandleStatus(unsigned char id, PayloadStatus status) {
+void _relayHandleStatus(size_t id, PayloadStatus status) {
     switch (status) {
     case PayloadStatus::Off:
         relayStatus(id, false);
@@ -615,7 +608,7 @@ void _relayHandleStatus(unsigned char id, PayloadStatus status) {
     }
 }
 
-bool _relayHandlePayload(unsigned char id, const char* payload) {
+bool _relayHandlePayload(size_t id, const char* payload) {
     auto status = relayParsePayload(payload);
     if (status != PayloadStatus::Unknown) {
         _relayHandleStatus(id, status);
@@ -626,11 +619,11 @@ bool _relayHandlePayload(unsigned char id, const char* payload) {
     return false;
 }
 
-bool _relayHandlePayload(unsigned char id, const String& payload) {
+bool _relayHandlePayload(size_t id, const String& payload) {
     return _relayHandlePayload(id, payload.c_str());
 }
 
-bool _relayHandlePulsePayload(unsigned char id, const char* payload) {
+bool _relayHandlePulsePayload(size_t id, const char* payload) {
     unsigned long pulse = 1000 * atof(payload);
     if (!pulse) {
         return false;
@@ -647,7 +640,7 @@ bool _relayHandlePulsePayload(unsigned char id, const char* payload) {
     return true;
 }
 
-bool _relayHandlePulsePayload(unsigned char id, const String& payload) {
+bool _relayHandlePulsePayload(size_t id, const String& payload) {
     return _relayHandlePulsePayload(id, payload.c_str());
 }
 
@@ -665,7 +658,7 @@ PayloadStatus _relayInvertStatus(PayloadStatus status) {
     return PayloadStatus::Unknown;
 }
 
-PayloadStatus _relayPayloadStatus(unsigned char id) {
+PayloadStatus _relayPayloadStatus(size_t id) {
     if (id < _relays.size()) {
         return _relays[id].current_status
             ? PayloadStatus::On
@@ -689,7 +682,7 @@ void _relayUnlockAll() {
     _relay_sync_locked = false;
 }
 
-bool _relayStatusLock(unsigned char id, bool status) {
+bool _relayStatusLock(size_t id, bool status) {
     if (_relays[id].lock != RelayLock::None) {
         bool lock = _relays[id].lock == RelayLock::On;
         if ((lock != status) || (lock != _relays[id].target_status)) {
@@ -705,7 +698,7 @@ bool _relayStatusLock(unsigned char id, bool status) {
 // https://github.com/xoseperez/espurna/issues/1510#issuecomment-461894516
 // completely reset timing on the other relay to sync with this one
 // to ensure that they change state sequentially
-void _relaySyncRelaysDelay(unsigned char first, unsigned char second) {
+void _relaySyncRelaysDelay(size_t first, size_t second) {
     _relays[second].fw_start = _relays[first].change_start;
     _relays[second].fw_count = 1;
     _relays[second].change_delay = std::max({
@@ -780,7 +773,7 @@ inline void _relayMaskSettings(const RelayMaskHelper& mask) {
 // Pulse timers (timer after ON or OFF event)
 // TODO: integrate with scheduled ON or OFF
 
-void relayPulse(unsigned char id) {
+void relayPulse(size_t id) {
 
     auto& relay = _relays[id];
     if (!relay.pulseTicker) {
@@ -814,15 +807,15 @@ void relayPulse(unsigned char id) {
         DEBUG_MSG_P(PSTR("[RELAY] Scheduling relay #%u back in %lums (pulse)\n"), id, ms);
         relay.pulseTicker->once_ms(ms, relayToggle, id);
         // Reconfigure after dynamic pulse
-        relay.pulse = getSetting({"relayPulse", id}, _relayPulseMode(id));
-        relay.pulse_ms = static_cast<unsigned long>(1000.0f * getSetting({"relayTime", id}, _relayPulseTime(id)));
+        relay.pulse = getSetting({"relayPulse", id},relay::build::pulseMode(id));
+        relay.pulse_ms = static_cast<unsigned long>(1000.0f * getSetting({"relayTime", id}, relay::build::pulseTime(id)));
     }
 
 }
 
 // General relay status control
 
-bool relayStatus(unsigned char id, bool status, bool report, bool group_report) {
+bool relayStatus(size_t id, bool status, bool report, bool group_report) {
 
     if ((id >= RelaysMax) || (id >= _relays.size())) {
         return false;
@@ -903,7 +896,7 @@ bool relayStatus(unsigned char id, bool status, bool report, bool group_report)
 
 }
 
-bool relayStatus(unsigned char id, bool status) {
+bool relayStatus(size_t id, bool status) {
 #if MQTT_SUPPORT
     return relayStatus(id, status, mqttForward(), true);
 #else
@@ -911,7 +904,7 @@ bool relayStatus(unsigned char id, bool status) {
 #endif
 }
 
-bool relayStatus(unsigned char id) {
+bool relayStatus(size_t id) {
 
     // Check that relay ID is valid
     if (id >= _relays.size()) return false;
@@ -921,35 +914,40 @@ bool relayStatus(unsigned char id) {
 
 }
 
-bool relayStatusTarget(unsigned char id) {
+bool relayStatusTarget(size_t id) {
     if (id >= _relays.size()) return false;
     return _relays[id].target_status;
 }
 
-void relaySync(unsigned char id) {
-
-    // No sync if none or only one relay
-    if (_relays.size() < 2) return;
+void relaySync(size_t target) {
 
     // Do not go on if we are comming from a previous sync
-    if (_relayRecursive) return;
-
-    // Flag sync mode
+    if (_relayRecursive) {
+        return;
+    }
     _relayRecursive = true;
 
-    bool status = _relays[id].target_status;
+    // No sync if none or only one relay
+    auto relays = _relays.size();
+    if (relays < 2) {
+        return;
+    }
+
+    bool status = _relays[target].target_status;
 
     // If RELAY_SYNC_SAME all relays should have the same state
     if (_relay_sync_mode == RELAY_SYNC_SAME) {
-        for (unsigned short i=0; i<_relays.size(); i++) {
-            if (i != id) relayStatus(i, status);
+        for (decltype(relays) id = 0; id < relays; ++id) {
+            if (id != target) {
+                relayStatus(id, status);
+            }
         }
 
     // If RELAY_SYNC_FIRST all relays should have the same state as first if first changes
     } else if (_relay_sync_mode == RELAY_SYNC_FIRST) {
-        if (id == 0) {
-            for (unsigned short i=1; i<_relays.size(); i++) {
-                relayStatus(i, status);
+        if (target == 0) {
+            for (decltype(relays) id = 1; id < relays; ++id) {
+                relayStatus(id, status);
             }
         }
 
@@ -957,11 +955,11 @@ void relaySync(unsigned char id) {
         // If NONE_OR_ONE or ONE and setting ON we should set OFF all the others
         if (status) {
             if (_relay_sync_mode != RELAY_SYNC_ANY) {
-                for (unsigned short other_id=0; other_id<_relays.size(); other_id++) {
-                    if (other_id != id) {
-                        relayStatus(other_id, false);
-                        if (relayStatus(other_id)) {
-                            _relaySyncRelaysDelay(other_id, id);
+                for (decltype(relays) id = 0; id < relays; ++id) {
+                    if (id != target) {
+                        relayStatus(id, false);
+                        if (relayStatus(id)) {
+                            _relaySyncRelaysDelay(id, target);
                         }
                     }
                 }
@@ -969,22 +967,21 @@ void relaySync(unsigned char id) {
         // If ONLY_ONE and setting OFF we should set ON the other one
         } else {
             if (_relay_sync_mode == RELAY_SYNC_ONE) {
-                unsigned char other_id = (id + 1) % _relays.size();
-                _relaySyncRelaysDelay(id, other_id);
-                relayStatus(other_id, true);
+                auto id = (target + 1) % relays;
+                _relaySyncRelaysDelay(target, id);
+                relayStatus(id, true);
             }
         }
         _relayLockAll();
     }
 
-    // Unflag sync mode
     _relayRecursive = false;
 
 }
 
 void relaySave(bool persist) {
     RelayMaskHelper mask;
-    for (unsigned char id = 0; id < _relays.size(); ++id) {
+    for (size_t id = 0; id < _relays.size(); ++id) {
         mask.set(id, _relays[id].current_status);
     }
 
@@ -1008,13 +1005,13 @@ void relaySave() {
     relaySave(false);
 }
 
-void relayToggle(unsigned char id, bool report, bool group_report) {
+void relayToggle(size_t id, bool report, bool group_report) {
     if (id < _relays.size()) {
         relayStatus(id, !relayStatus(id), report, group_report);
     }
 }
 
-void relayToggle(unsigned char id) {
+void relayToggle(size_t id) {
 #if MQTT_SUPPORT
     relayToggle(id, mqttForward(), true);
 #else
@@ -1050,7 +1047,7 @@ void _relaySettingsMigrate(int version) {
         moveSetting("relayDelayInterlock", "relayIlkDelay");
 
         // groups use a new set of keys
-        for (unsigned char index = 0; index < RelaysMax; ++index) {
+        for (size_t index = 0; index < RelaysMax; ++index) {
             auto group = getSetting({"mqttGroup", index});
             if (!group.length()) {
                 break;
@@ -1072,7 +1069,7 @@ void _relaySettingsMigrate(int version) {
             "mqttGroup",     // migrated to relayTopic
             "mqttGroupSync", // migrated to relayTopic
             "relayOnDisc",   // replaced with relayMqttDisc
-            "relayGPIO",     // avoid depending on migrate.ino
+            "relayGpio",     // avoid depending on migrate.ino
             "relayProvider", // different type
             "relayType",     // different type
         });
@@ -1080,8 +1077,8 @@ void _relaySettingsMigrate(int version) {
     }
 }
 
-void _relayBoot(unsigned char index, const RelayMaskHelper& mask) {
-    const auto boot_mode = getSetting({"relayBoot", index}, _relayBootMode(index));
+void _relayBoot(size_t index, const RelayMaskHelper& mask) {
+    const auto boot_mode = getSetting({"relayBoot", index}, relay::build::bootMode(index));
 
     auto status = false;
     auto lock = RelayLock::None;
@@ -1154,24 +1151,24 @@ void _relayBootAll() {
 void _relayConfigure() {
     auto relays = _relays.size();
     for (decltype(relays) id = 0; id < relays; ++id) {
-        _relays[id].pulse = getSetting({"relayPulse", id}, _relayPulseMode(id));
-        _relays[id].pulse_ms = static_cast<unsigned long>(1000.0f * getSetting({"relayTime", i}, _relayPulseTime(i)));
+        _relays[id].pulse = getSetting({"relayPulse", id}, relay::build::pulseMode(id));
+        _relays[id].pulse_ms = static_cast<unsigned long>(1000.0f * getSetting({"relayTime", id}, relay::build::pulseTime(id)));
 
-        _relays[id].delay_on = getSetting({"relayDelayOn", id}, _relayDelayOn(id));
-        _relays[id].delay_off = getSetting({"relayDelayOff", id}, _relayDelayOff(id));
+        _relays[id].delay_on = getSetting({"relayDelayOn", id}, relay::build::delayOn(id));
+        _relays[id].delay_off = getSetting({"relayDelayOff", id}, relay::build::delayOff(id));
     }
 
-    _relay_flood_window = (1000.0f * getSetting("relayFloodTime", _relayFloodWindow()));
-    _relay_flood_changes = getSetting("relayFloodChanges", _relayFloodChanges());
+    _relay_flood_window = (1000.0f * getSetting("relayFloodTime", relay::build::floodWindow()));
+    _relay_flood_changes = getSetting("relayFloodChanges", relay::build::floodChanges());
 
-    _relay_delay_interlock = getSetting("relayIlkDelay", _relayInterlockDelay());
-    _relay_sync_mode = getSetting("relaySync", _relaySyncMode());
+    _relay_delay_interlock = getSetting("relayIlkDelay", relay::build::interlockDelay());
+    _relay_sync_mode = getSetting("relaySync", relay::build::syncMode());
 
     #if MQTT_SUPPORT || API_SUPPORT
         settingsProcessConfig({
-            {_relay_rpc_payload_on,     "relayPayloadOn",     _relayMqttPayloadOn()},
-            {_relay_rpc_payload_off,    "relayPayloadOff",    _relayMqttPayloadOff()},
-            {_relay_rpc_payload_toggle, "relayPayloadToggle", _relayMqttPayloadToggle()},
+            {_relay_rpc_payload_on,     "relayPayloadOn",     relay::build::mqttPayloadOn()},
+            {_relay_rpc_payload_off,    "relayPayloadOff",    relay::build::mqttPayloadOff()},
+            {_relay_rpc_payload_toggle, "relayPayloadToggle", relay::build::mqttPayloadToggle()},
         });
     #endif // MQTT_SUPPORT
 }
@@ -1202,17 +1199,17 @@ void _relayWebSocketUpdate(JsonObject& root) {
 }
 
 void _relayWebSocketRelayConfig(JsonArray& relay, size_t id) {
-    relay.add(static_cast<uint8_t>(getSetting({"relayProv", id}, _relayProvider(id))));
+    relay.add(static_cast<uint8_t>(getSetting({"relayProv", id}, relay::build::provider(id))));
     relay.add(getSetting({"relayName", id}));
-    relay.add(getSetting({"relayBoot", id}, _relayBootMode(id)));
+    relay.add(getSetting({"relayBoot", id}, relay::build::bootMode(id)));
 
 #if MQTT_SUPPORT
-    relay.add(getSetting({"relayTopicSub", id}, _relayMqttTopicSub(id)));
-    relay.add(getSetting({"relayTopicPub", id}, _relayMqttTopicPub(id)));
+    relay.add(getSetting({"relayTopicSub", id}, relay::build::mqttTopicSub(id)));
+    relay.add(getSetting({"relayTopicPub", id}, relay::build::mqttTopicPub(id)));
     relay.add(static_cast<uint8_t>(getSetting({"relayTopicMode", id},
-            _relayMqttTopicMode(id))));
+            relay::build::mqttTopicMode(id))));
     relay.add(static_cast<uint8_t>(getSetting({"relayMqttDisc", id},
-            _relayMqttDisconnectionStatus(id))));
+            relay::build::mqttDisconnectionStatus(id))));
 #endif
 
     relay.add(static_cast<uint8_t>(_relays[id].pulse));
@@ -1266,8 +1263,8 @@ void _relayWebSocketOnVisible(JsonObject& root) {
 
     if (relayCount() > 1) {
         root["multirelayVisible"] = 1;
-        root["relaySync"] = static_cast<uint8_t>(getSetting("relaySync", _relaySyncMode()));
-        root["relayIlkDelay"] = getSetting("relayIlkDelay", _relayInterlockDelay());
+        root["relaySync"] = static_cast<uint8_t>(getSetting("relaySync", relay::build::syncMode()));
+        root["relayIlkDelay"] = getSetting("relayIlkDelay", relay::build::interlockDelay());
     }
 
     root["relayVisible"] = 1;
@@ -1314,7 +1311,7 @@ void relaySetupWS() {
 template <typename T>
 bool _relayApiTryHandle(ApiRequest& request, T&& callback) {
     auto id_param = request.wildcard(0);
-    unsigned char id;
+    size_t id;
     if (!_relayTryParseId(id_param.c_str(), id)) {
         return false;
     }
@@ -1331,7 +1328,7 @@ void relaySetupAPI() {
     apiRegister(F(MQTT_TOPIC_RELAY),
         [](ApiRequest&, JsonObject& root) {
             JsonArray& relays = root.createNestedArray("relayStatus");
-            for (unsigned char id = 0; id < relayCount(); ++id) {
+            for (size_t id = 0; id < relayCount(); ++id) {
                 relays.add(_relays[id].target_status ? 1 : 0);
             }
             return true;
@@ -1341,13 +1338,13 @@ void relaySetupAPI() {
 
     apiRegister(F(MQTT_TOPIC_RELAY "/+"),
         [](ApiRequest& request) {
-            return _relayApiTryHandle(request, [&](unsigned char id) {
+            return _relayApiTryHandle(request, [&](size_t id) {
                 request.send(String(_relays[id].target_status ? 1 : 0));
                 return true;
             });
         },
         [](ApiRequest& request) {
-            return _relayApiTryHandle(request, [&](unsigned char id) {
+            return _relayApiTryHandle(request, [&](size_t id) {
                 return _relayHandlePayload(id, request.param(F("value")));
             });
         }
@@ -1355,13 +1352,13 @@ void relaySetupAPI() {
 
     apiRegister(F(MQTT_TOPIC_PULSE "/+"),
         [](ApiRequest& request) {
-            return _relayApiTryHandle(request, [&](unsigned char id) {
+            return _relayApiTryHandle(request, [&](size_t id) {
                 request.send(String(static_cast<double>(_relays[id].pulse_ms) / 1000));
                 return true;
             });
         },
         [](ApiRequest& request) {
-            return _relayApiTryHandle(request, [&](unsigned char id) {
+            return _relayApiTryHandle(request, [&](size_t id) {
                 return _relayHandlePulsePayload(id, request.param(F("value")));
             });
         }
@@ -1478,7 +1475,7 @@ struct RelayCustomTopic {
         _mode(base.mode())
     {}
 
-    unsigned char id() const {
+    size_t id() const {
         return _id;
     }
 
@@ -1508,7 +1505,7 @@ struct RelayCustomTopic {
     }
 
 private:
-    unsigned char _id;
+    size_t _id;
     String _topic;
     PathParts _parts;
     RelayMqttTopicMode _mode;
@@ -1524,7 +1521,7 @@ void _relayMqttSubscribeCustomTopics() {
 
     static std::vector<RelayCustomTopicBase> topics;
     for (size_t id = 0; id < relays; ++id) {
-        topics.emplace_back(_relayMqttTopicSub(id), _relayMqttTopicMode(id));
+        topics.emplace_back(relay::build::mqttTopicSub(id), relay::build::mqttTopicMode(id));
     }
 
     settings::kv_store.foreach([&](settings::kvs_type::KeyValueResult&& kv) {
@@ -1541,22 +1538,21 @@ void _relayMqttSubscribeCustomTopics() {
         }
 
         const auto key = kv.key.read();
-        unsigned char id;
+        size_t id;
 
         if (key.startsWith(SubPrefix)) {
             if (_relayTryParseId(key.c_str() + strlen(SubPrefix), id)) {
                 topics[id] = std::move(kv.value.read());
             }
         } else if (key.startsWith(ModePrefix)) {
-            using namespace settings::internal;
             if (_relayTryParseId(key.c_str() + strlen(ModePrefix), id)) {
-                topics[id] = convert<RelayMqttTopicMode>(kv.value.read());
+                topics[id] = settings::internal::convert<RelayMqttTopicMode>(kv.value.read());
             }
         }
     });
 
     _relay_custom_topics.clear();
-    for (unsigned char id = 0; id < relays; ++id) {
+    for (size_t id = 0; id < relays; ++id) {
         RelayCustomTopicBase& topic = topics[id];
         auto& value = topic.value();
         if (!value.length()) {
@@ -1570,15 +1566,15 @@ void _relayMqttSubscribeCustomTopics() {
     topics.clear();
 }
 
-void _relayMqttPublishCustomTopic(unsigned char id) {
-    const String topic = getSetting({"relayTopicPub", id}, _relayMqttTopicPub(id));
+void _relayMqttPublishCustomTopic(size_t id) {
+    const String topic = getSetting({"relayTopicPub", id}, relay::build::mqttTopicPub(id));
     if (!topic.length()) {
         return;
     }
 
     auto status = _relayPayloadStatus(id);
 
-    auto mode = getSetting({"relayTopicMode", id}, _relayMqttTopicMode(id));
+    auto mode = getSetting({"relayTopicMode", id}, relay::build::mqttTopicMode(id));
     if (mode == RelayMqttTopicMode::Inverse) {
         status = _relayInvertStatus(status);
     }
@@ -1588,7 +1584,7 @@ void _relayMqttPublishCustomTopic(unsigned char id) {
 
 } // namespace
 
-void _relayMqttReport(unsigned char id) {
+void _relayMqttReport(size_t id) {
     if (id < _relays.size()) {
         if (_relays[id].report) {
             _relays[id].report = false;
@@ -1608,7 +1604,7 @@ void _relayMqttReportAll() {
     }
 }
 
-void relayStatusWrap(unsigned char id, PayloadStatus value, bool is_group_topic) {
+void relayStatusWrap(size_t id, PayloadStatus value, bool is_group_topic) {
     #if MQTT_SUPPORT
         const auto forward = mqttForward();
     #else
@@ -1664,7 +1660,7 @@ void _relayMqttHandleDisconnect() {
 
         const auto key = kv.key.read();
         if (key.startsWith(prefix)) {
-            unsigned char id;
+            size_t id;
             if (_relayTryParseId(key.c_str() + strlen(prefix), id)) {
                 const auto value = kv.value.read();
                 _relayHandleStatus(id, relayParsePayload(value.c_str()));
@@ -1704,7 +1700,7 @@ void relayMQTTCallback(unsigned int type, const char * topic, const char * paylo
         auto is_relay = t.startsWith(MQTT_TOPIC_RELAY);
         auto is_pulse = t.startsWith(MQTT_TOPIC_PULSE);
         if (is_relay || is_pulse) {
-            unsigned char id;
+            size_t id;
             if (!_relayTryParseIdFromPath(t.c_str(), id)) {
                 return;
             }
@@ -1752,8 +1748,8 @@ void relaySetupMQTT() {
 void _relayInitCommands() {
 
     terminalRegisterCommand(F("RELAY"), [](const terminal::CommandContext& ctx) {
-        auto showRelays = [&](unsigned char start, unsigned char stop, bool full = true) {
-            for (unsigned char index = start; index < stop; ++index) {
+        auto showRelays = [&](size_t start, size_t stop, bool full = true) {
+            for (size_t index = start; index < stop; ++index) {
                 auto& relay = _relays[index];
 
                 char pulse_info[64] = "";
@@ -1795,7 +1791,7 @@ void _relayInitCommands() {
             return;
         }
 
-        unsigned char id;
+        size_t id;
         if (!_relayTryParseId(ctx.argv[1].c_str(), id)) {
             terminalError(ctx, F("Invalid relayID"));
             return;
@@ -1821,7 +1817,7 @@ void _relayInitCommands() {
 
 //------------------------------------------------------------------------------
 
-void _relayReport(unsigned char id [[gnu::unused]], bool status [[gnu::unused]]) {
+void _relayReport(size_t id [[gnu::unused]], bool status [[gnu::unused]]) {
     for (auto& change : _relay_status_change) {
         change(id, status);
     }
@@ -1873,7 +1869,7 @@ void _relayProcess(bool mode) {
 
             // We will trigger a eeprom save only if
             // we care about current relay status on boot
-            const auto boot_mode = getSetting({"relayBoot", id}, _relayBootMode(id));
+            const auto boot_mode = getSetting({"relayBoot", id}, relay::build::bootMode(id));
             const bool save_eeprom = ((RELAY_BOOT_SAME == boot_mode) || (RELAY_BOOT_TOGGLE == boot_mode));
             _relay_save_timer.once_ms(RELAY_SAVE_DELAY, relaySave, save_eeprom);
 
@@ -1887,7 +1883,7 @@ void _relayProcess(bool mode) {
     // Whenever we are using sync modes and any relay had changed the state, check if we can unlock
     switch (_relay_sync_mode) {
     case RELAY_SYNC_ONE:
-    case RELAY_SYNC_NONE_OR_ONE
+    case RELAY_SYNC_NONE_OR_ONE:
         if (_relay_sync_locked && changed) {
             _relaySyncUnlock();
         }
@@ -1969,14 +1965,14 @@ struct RelayGpioProviderCfg {
     uint8_t reset;
 };
 
-RelayGpioProviderCfg _relayGpioProviderCfg(unsigned char index) {
+RelayGpioProviderCfg _relayGpioProviderCfg(size_t index) {
     return {
-        gpioBase(getSetting({"relayGPIOType", index}, _relayPinType(index))),
-        getSetting({"relayGPIO", index}, _relayPin(index)),
-        getSetting({"relayResetGPIO", index}, _relayResetPin(index))};
+        gpioBase(getSetting({"relayGpioType", index}, relay::build::pinType(index))),
+        getSetting({"relayGpio", index}, relay::build::pin(index)),
+        getSetting({"relayResetGpio", index}, relay::build::resetPin(index))};
 }
 
-std::unique_ptr<GpioProvider> _relayGpioProvider(unsigned char index, RelayType type) {
+std::unique_ptr<GpioProvider> _relayGpioProvider(size_t index, RelayType type) {
     auto cfg = _relayGpioProviderCfg(index);
     if (!cfg.base) {
         return nullptr;
@@ -1992,9 +1988,9 @@ std::unique_ptr<GpioProvider> _relayGpioProvider(unsigned char index, RelayType
     return nullptr;
 }
 
-RelayProviderBasePtr _relaySetupProvider(unsigned char index) {
-    auto provider = getSetting({"relayProv", index}, _relayProvider(index));
-    auto type = getSetting({"relayType", index}, _relayType(index));
+RelayProviderBasePtr _relaySetupProvider(size_t index) {
+    auto provider = getSetting({"relayProv", index}, relay::build::provider(index));
+    auto type = getSetting({"relayType", index}, relay::build::type(index));
 
     RelayProviderBasePtr result;
 
@@ -2026,7 +2022,7 @@ void _relaySetup() {
     auto relays = _relays.size();
     _relays.reserve(relays + _relayAdhocPins());
 
-    for (unsigned char id = relays; id < RelaysMax; ++id) {
+    for (size_t id = relays; id < RelaysMax; ++id) {
         auto impl = _relaySetupProvider(id);
         if (!impl) {
             break;
@@ -2037,7 +2033,7 @@ void _relaySetup() {
         _relays.emplace_back(std::move(impl));
     }
 
-    relaySetupDummy(getSetting("relayDummy", DUMMY_RELAY_COUNT));
+    relaySetupDummy(getSetting("relayDummy", relay::build::dummyCount()));
 }
 
 void relaySetup() {
diff --git a/code/espurna/relay.h b/code/espurna/relay.h
index 27b6120e..71ef5aee 100644
--- a/code/espurna/relay.h
+++ b/code/espurna/relay.h
@@ -70,17 +70,17 @@ public:
 
 PayloadStatus relayParsePayload(const char * payload);
 
-bool relayStatus(unsigned char id, bool status, bool report, bool group_report);
-bool relayStatus(unsigned char id, bool status);
+bool relayStatus(size_t id, bool status, bool report, bool group_report);
+bool relayStatus(size_t id, bool status);
 
 // gets either current or target status, where current is the status that we are
 // actually in and target is the status we would be, eventually, unless
 // relayStatus(id, relayStatus()) is called
-bool relayStatus(unsigned char id);
-bool relayStatusTarget(unsigned char id);
+bool relayStatus(size_t id);
+bool relayStatusTarget(size_t id);
 
-void relayToggle(unsigned char id, bool report, bool group_report);
-void relayToggle(unsigned char id);
+void relayToggle(size_t id, bool report, bool group_report);
+void relayToggle(size_t id);
 
 size_t relayCount();
 
@@ -90,8 +90,8 @@ const String& relayPayloadToggle();
 
 const char* relayPayload(PayloadStatus status);
 
-void relayPulse(unsigned char id);
-void relaySync(unsigned char id);
+void relayPulse(size_t id);
+void relaySync(size_t id);
 void relaySave(bool persist);
 
 using RelayStatusCallback = void(*)(size_t id, bool status);
diff --git a/code/espurna/relay_config.h b/code/espurna/relay_config.h
index e8789f73..7bb19d07 100644
--- a/code/espurna/relay_config.h
+++ b/code/espurna/relay_config.h
@@ -8,29 +8,36 @@ RELAY MODULE
 
 #include "espurna.h"
 
-constexpr int _relaySyncMode() {
+namespace relay {
+namespace build {
+
+constexpr size_t dummyCount() {
+    return DUMMY_RELAY_COUNT;
+}
+
+constexpr int syncMode() {
     return RELAY_SYNC;
 }
 
-constexpr float _relayFloodWindow() {
+constexpr float floodWindow() {
     return RELAY_FLOOD_WINDOW;
 }
 
-static_assert(_relayFloodWindow() >= 0.0f, "");
+static_assert(floodWindow() >= 0.0f, "");
 
-constexpr unsigned long _relayFloodWindowMs() {
-    return static_cast<unsigned long>(_relayFloodWindow() * 1000.0f);
+constexpr unsigned long floodWindowMs() {
+    return static_cast<unsigned long>(floodWindow() * 1000.0f);
 }
 
-constexpr unsigned long _relayFloodChanges() {
+constexpr unsigned long floodChanges() {
     return RELAY_FLOOD_CHANGES;
 }
 
-constexpr unsigned long _relayInterlockDelay() {
+constexpr unsigned long interlockDelay() {
     return RELAY_DELAY_INTERLOCK;
 }
 
-constexpr float _relayPulseTime(unsigned char index) {
+constexpr float pulseTime(size_t index) {
     return (
         (index == 0) ? RELAY1_PULSE_TIME :
         (index == 1) ? RELAY2_PULSE_TIME :
@@ -43,16 +50,16 @@ constexpr float _relayPulseTime(unsigned char index) {
     );
 }
 
-static_assert(_relayPulseTime(0) >= 0.0f, "");
-static_assert(_relayPulseTime(1) >= 0.0f, "");
-static_assert(_relayPulseTime(2) >= 0.0f, "");
-static_assert(_relayPulseTime(3) >= 0.0f, "");
-static_assert(_relayPulseTime(4) >= 0.0f, "");
-static_assert(_relayPulseTime(5) >= 0.0f, "");
-static_assert(_relayPulseTime(6) >= 0.0f, "");
-static_assert(_relayPulseTime(7) >= 0.0f, "");
+static_assert(pulseTime(0) >= 0.0f, "");
+static_assert(pulseTime(1) >= 0.0f, "");
+static_assert(pulseTime(2) >= 0.0f, "");
+static_assert(pulseTime(3) >= 0.0f, "");
+static_assert(pulseTime(4) >= 0.0f, "");
+static_assert(pulseTime(5) >= 0.0f, "");
+static_assert(pulseTime(6) >= 0.0f, "");
+static_assert(pulseTime(7) >= 0.0f, "");
 
-constexpr RelayPulse _relayPulseMode(unsigned char index) {
+constexpr RelayPulse pulseMode(size_t index) {
     return (
         (index == 0) ? RELAY1_PULSE_MODE :
         (index == 1) ? RELAY2_PULSE_MODE :
@@ -65,7 +72,7 @@ constexpr RelayPulse _relayPulseMode(unsigned char index) {
     );
 }
 
-constexpr unsigned long _relayDelayOn(unsigned char index) {
+constexpr unsigned long delayOn(size_t index) {
     return (
         (index == 0) ? RELAY1_DELAY_ON :
         (index == 1) ? RELAY2_DELAY_ON :
@@ -78,7 +85,7 @@ constexpr unsigned long _relayDelayOn(unsigned char index) {
     );
 }
 
-constexpr unsigned long _relayDelayOff(unsigned char index) {
+constexpr unsigned long delayOff(size_t index) {
     return (
         (index == 0) ? RELAY1_DELAY_OFF :
         (index == 1) ? RELAY2_DELAY_OFF :
@@ -91,7 +98,7 @@ constexpr unsigned long _relayDelayOff(unsigned char index) {
     );
 }
 
-constexpr unsigned char _relayPin(unsigned char index) {
+constexpr unsigned char pin(size_t index) {
     return (
         (index == 0) ? RELAY1_PIN :
         (index == 1) ? RELAY2_PIN :
@@ -104,7 +111,7 @@ constexpr unsigned char _relayPin(unsigned char index) {
     );
 }
 
-constexpr RelayType _relayType(unsigned char index) {
+constexpr RelayType type(size_t index) {
     return (
         (index == 0) ? RELAY1_TYPE :
         (index == 1) ? RELAY2_TYPE :
@@ -117,7 +124,7 @@ constexpr RelayType _relayType(unsigned char index) {
     );
 }
 
-constexpr GpioType _relayPinType(unsigned char index) {
+constexpr GpioType pinType(size_t index) {
     return (
         (index == 0) ? RELAY1_PIN_TYPE :
         (index == 1) ? RELAY2_PIN_TYPE :
@@ -130,7 +137,7 @@ constexpr GpioType _relayPinType(unsigned char index) {
     );
 }
 
-constexpr unsigned char _relayResetPin(unsigned char index) {
+constexpr unsigned char resetPin(size_t index) {
     return (
         (index == 0) ? RELAY1_RESET_PIN :
         (index == 1) ? RELAY2_RESET_PIN :
@@ -143,7 +150,7 @@ constexpr unsigned char _relayResetPin(unsigned char index) {
     );
 }
 
-constexpr int _relayBootMode(unsigned char index) {
+constexpr int bootMode(size_t index) {
     return (
         (index == 0) ? RELAY1_BOOT_MODE :
         (index == 1) ? RELAY2_BOOT_MODE :
@@ -156,7 +163,7 @@ constexpr int _relayBootMode(unsigned char index) {
     );
 }
 
-constexpr RelayProvider _relayProvider(unsigned char index) {
+constexpr RelayProvider provider(size_t index) {
     return (
         (index == 0) ? (RELAY1_PROVIDER) :
         (index == 1) ? (RELAY2_PROVIDER) :
@@ -169,7 +176,7 @@ constexpr RelayProvider _relayProvider(unsigned char index) {
     );
 }
 
-constexpr RelayMqttTopicMode _relayMqttTopicMode(unsigned char index) {
+constexpr RelayMqttTopicMode mqttTopicMode(size_t index) {
     return (
         (index == 0) ? (RELAY1_MQTT_TOPIC_MODE) :
         (index == 1) ? (RELAY2_MQTT_TOPIC_MODE) :
@@ -182,19 +189,19 @@ constexpr RelayMqttTopicMode _relayMqttTopicMode(unsigned char index) {
     );
 }
 
-constexpr const char* const _relayMqttPayloadOn() {
+constexpr const char* const mqttPayloadOn() {
     return RELAY_MQTT_ON;
 }
 
-constexpr const char* const _relayMqttPayloadOff() {
+constexpr const char* const mqttPayloadOff() {
     return RELAY_MQTT_OFF;
 }
 
-constexpr const char* const _relayMqttPayloadToggle() {
+constexpr const char* const mqttPayloadToggle() {
     return RELAY_MQTT_TOGGLE;
 }
 
-constexpr const char* const _relayMqttTopicSub(unsigned char index) {
+constexpr const char* const mqttTopicSub(size_t index) {
     return (
         (index == 0) ? (RELAY1_MQTT_TOPIC_SUB) :
         (index == 1) ? (RELAY2_MQTT_TOPIC_SUB) :
@@ -207,7 +214,7 @@ constexpr const char* const _relayMqttTopicSub(unsigned char index) {
     );
 }
 
-constexpr const char* const _relayMqttTopicPub(unsigned char index) {
+constexpr const char* const mqttTopicPub(size_t index) {
     return (
         (index == 0) ? (RELAY1_MQTT_TOPIC_PUB) :
         (index == 1) ? (RELAY2_MQTT_TOPIC_PUB) :
@@ -220,7 +227,7 @@ constexpr const char* const _relayMqttTopicPub(unsigned char index) {
     );
 }
 
-constexpr PayloadStatus _relayMqttDisconnectionStatus(unsigned char index) {
+constexpr PayloadStatus mqttDisconnectionStatus(size_t index) {
     return (
         (index == 0) ? (RELAY1_MQTT_DISCONNECT_STATUS) :
         (index == 1) ? (RELAY2_MQTT_DISCONNECT_STATUS) :
@@ -232,3 +239,6 @@ constexpr PayloadStatus _relayMqttDisconnectionStatus(unsigned char index) {
         (index == 7) ? (RELAY8_MQTT_DISCONNECT_STATUS) : RELAY_MQTT_DISCONNECT_NONE
     );
 }
+
+} // namespace build
+} // namespace relay
diff --git a/code/espurna/rfbridge.cpp b/code/espurna/rfbridge.cpp
index c605a894..110984ea 100644
--- a/code/espurna/rfbridge.cpp
+++ b/code/espurna/rfbridge.cpp
@@ -53,33 +53,39 @@ constexpr bool _rfb_transmit { true };
 
 struct RfbRelayMatch {
     RfbRelayMatch() = default;
-    RfbRelayMatch(unsigned char id_, PayloadStatus status_) :
-        id(id_),
-        status(status_),
+    RfbRelayMatch(size_t id, PayloadStatus status) :
+        _id(id),
+        _status(status),
         _found(true)
     {}
 
-    bool ok() {
-        return _found;
+    void reset(size_t id, PayloadStatus status) {
+        _id = id;
+        _status = status;
+        _found = true;
     }
 
-    void reset(unsigned char id_, PayloadStatus status_) {
-        id = id_;
-        status = status_;
-        _found = true;
+    size_t id() const {
+        return _id;
     }
 
-    unsigned char id { 0u };
-    PayloadStatus status { PayloadStatus::Unknown };
+    PayloadStatus status() const {
+        return _status;
+    }
 
-    private:
+    explicit operator bool() const {
+        return _found;
+    }
 
+private:
+    size_t _id { RelaysMax };
+    PayloadStatus _status { PayloadStatus::Unknown };
     bool _found { false };
 };
 
 struct RfbLearn {
     unsigned long ts;
-    unsigned char id;
+    size_t id;
     bool status;
 };
 
@@ -332,7 +338,7 @@ void _rfbWebSocketOnVisible(JsonObject& root) {
 
 #if RELAY_SUPPORT
 
-void _rfbWebSocketSendCodeArray(JsonObject& root, unsigned char start, unsigned char size) {
+void _rfbWebSocketSendCodeArray(JsonObject& root, size_t start, size_t size) {
     JsonObject& rfb = root.createNestedObject("rfb");
     rfb["size"] = size;
     rfb["start"] = start;
@@ -340,14 +346,14 @@ void _rfbWebSocketSendCodeArray(JsonObject& root, unsigned char start, unsigned
     JsonArray& on = rfb.createNestedArray("on");
     JsonArray& off = rfb.createNestedArray("off");
 
-    for (uint8_t id=start; id<start+size; id++) {
+    for (auto id = start; id < (start + size); ++id) {
         on.add(rfbRetrieve(id, true));
         off.add(rfbRetrieve(id, false));
     }
 }
 
 void _rfbWebSocketOnData(JsonObject& root) {
-    _rfbWebSocketSendCodeArray(root, 0, relayCount());
+    _rfbWebSocketSendCodeArray(root, 0ul, relayCount());
 }
 
 #endif // RELAY_SUPPORT
@@ -447,23 +453,18 @@ RfbRelayMatch _rfbMatch(const char* code) {
             return;
         }
 
-        char *endptr = nullptr;
-        const auto id = strtoul(id_ptr, &endptr, 10);
-        if (endptr == id_ptr || endptr[0] != '\0' || id > std::numeric_limits<uint8_t>::max() || id >= relayCount()) {
+        size_t id;
+        if (!tryParseId(id_ptr, relayCount, id)) {
             return;
         }
 
         // when we see the same id twice, we match the opposite statuses
-        if (matched.ok() && (id == matched.id)) {
-            matched.status = PayloadStatus::Toggle;
+        if (matched && (id == matched.id())) {
+            matched.reset(matched.id(), PayloadStatus::Toggle);
             return;
         }
 
-        matched.reset(matched.ok()
-            ? std::min(static_cast<uint8_t>(id), matched.id)
-            : static_cast<uint8_t>(id),
-            status
-        );
+        matched.reset(matched ? std::min(id, matched.id()) : id, status);
     });
 
 
@@ -482,7 +483,7 @@ void _rfbLearnFromString(std::unique_ptr<RfbLearn>& learn, const char* buffer) {
 #if WEB_SUPPORT
     auto id = learn->id;
     wsPost([id](JsonObject& root) {
-        _rfbWebSocketSendCodeArray(root, id, 1);
+        _rfbWebSocketSendCodeArray(root, id, 1ul);
     });
 #endif
 
@@ -493,18 +494,18 @@ bool _rfbRelayHandler(const char* buffer, bool locked = false) {
     bool result { false };
 
     auto match = _rfbMatch(buffer);
-    if (match.ok()) {
-        DEBUG_MSG_P(PSTR("[RF] Matched with the relay ID %u\n"), match.id);
-        _rfb_relay_status_lock.set(match.id, locked);
+    if (match) {
+        DEBUG_MSG_P(PSTR("[RF] Matched with the relay ID %u\n"), match.id());
+        _rfb_relay_status_lock.set(match.id(), locked);
 
-        switch (match.status) {
+        switch (match.status()) {
         case PayloadStatus::On:
         case PayloadStatus::Off:
-            relayStatus(match.id, (PayloadStatus::On == match.status));
+            relayStatus(match.id(), (PayloadStatus::On == match.status()));
             result = true;
             break;
         case PayloadStatus::Toggle:
-            relayToggle(match.id);
+            relayToggle(match.id());
             result = true;
         case PayloadStatus::Unknown:
             break;
@@ -529,13 +530,8 @@ void _rfbLearnStartFromPayload(const char* payload) {
 
     std::copy(payload, sep, relay);
 
-    char *endptr = nullptr;
-    const auto id = strtoul(relay, &endptr, 10);
-    if (endptr == &relay[0] || endptr[0] != '\0') {
-        return;
-    }
-
-    if (id >= relayCount()) {
+    size_t id;
+    if (!tryParseId(relay, relayCount(), id)) {
         DEBUG_MSG_P(PSTR("[RF] Invalid relay ID (%u)\n"), id);
         return;
     }
@@ -580,7 +576,7 @@ bool _rfbEnqueue(const char* code, size_t length, unsigned char repeats = 1u) {
     return false;
 }
 
-void _rfbSendRaw(const uint8_t* message, unsigned char size) {
+void _rfbSendRaw(const uint8_t* message, size_t size) {
     Serial.write(message, size);
 }
 
@@ -1075,6 +1071,20 @@ void _rfbApiSetup() {
 
 #if TERMINAL_SUPPORT
 
+void _rfbCommandStatusDispatch(const terminal::CommandContext& ctx, size_t id, const String& payload, RelayStatusCallback callback) {
+    auto parsed = rpcParsePayload(payload.c_str());
+    switch (parsed) {
+    case PayloadStatus::On:
+    case PayloadStatus::Off:
+        callback(id, (parsed == PayloadStatus::On));
+        return;
+    case PayloadStatus::Toggle:
+    case PayloadStatus::Unknown:
+        terminalError(ctx, F("Invalid status"));
+        break;
+    }
+}
+
 void _rfbInitCommands() {
 
     terminalRegisterCommand(F("RFB.SEND"), [](const terminal::CommandContext& ctx) {
@@ -1093,38 +1103,35 @@ void _rfbInitCommands() {
             return;
         }
 
-        int id = ctx.argv[1].toInt();
-        if (id >= relayCount()) {
+        size_t id;
+        if (!tryParseId(ctx.argv[1].c_str(), relayCount, id)) {
             terminalError(ctx, F("Invalid relay ID"));
             return;
         }
 
-        rfbLearn(id, (ctx.argv[2].toInt()) == 1);
-
-        terminalOK(ctx);
-
+        _rfbCommandStatusDispatch(ctx, id, ctx.argv[2], rfbLearn);
     });
 
     terminalRegisterCommand(F("RFB.FORGET"), [](const terminal::CommandContext& ctx) {
-
         if (ctx.argc < 2) {
             terminalError(ctx, F("RFB.FORGET <ID> [<STATUS>]"));
             return;
         }
 
-        int id = ctx.argv[1].toInt();
-        if (id >= relayCount()) {
+        size_t id;
+        if (!tryParseId(ctx.argv[1].c_str(), relayCount, id)) {
             terminalError(ctx, F("Invalid relay ID"));
             return;
         }
 
         if (ctx.argc == 3) {
-            rfbForget(id, (ctx.argv[2].toInt()) == 1);
-        } else {
-            rfbForget(id, true);
-            rfbForget(id, false);
+            _rfbCommandStatusDispatch(ctx, id, ctx.argv[2], rfbForget);
+            return;
         }
 
+        rfbForget(id, true);
+        rfbForget(id, false);
+
         terminalOK(ctx);
     });
 #endif // if RELAY_SUPPORT
@@ -1148,19 +1155,19 @@ void _rfbInitCommands() {
 // PUBLIC
 // -----------------------------------------------------------------------------
 
-void rfbStore(unsigned char id, bool status, const char * code) {
+void rfbStore(size_t id, bool status, const char * code) {
     SettingsKey key { status ? F("rfbON") : F("rfbOFF"), id };
     setSetting(key, code);
-    DEBUG_MSG_P(PSTR("[RF] Saved %s => \"%s\"\n"), key.toString().c_str(), code);
+    DEBUG_MSG_P(PSTR("[RF] Saved %s => \"%s\"\n"), key.c_str(), code);
 }
 
-String rfbRetrieve(unsigned char id, bool status) {
+String rfbRetrieve(size_t id, bool status) {
     return getSetting({ status ? F("rfbON") : F("rfbOFF"), id });
 }
 
 #if RELAY_SUPPORT
 
-void rfbStatus(unsigned char id, bool status) {
+void rfbStatus(size_t id, bool status) {
     // TODO: This is a left-over from the old implementation. Right now we set this lock when relay handler
     //       is called within the receiver, while this is called from either relayStatus or relay loop calling
     //       this via provider callback. This prevents us from re-sending the code we just received.
@@ -1173,12 +1180,12 @@ void rfbStatus(unsigned char id, bool status) {
     _rfb_relay_status_lock[id] = false;
 }
 
-void rfbLearn(unsigned char id, bool status) {
+void rfbLearn(size_t id, bool status) {
     _rfb_learn.reset(new RfbLearn { millis(), id, status });
     _rfbLearnImpl();
 }
 
-void rfbForget(unsigned char id, bool status) {
+void rfbForget(size_t id, bool status) {
 
     delSetting({status ? F("rfbON") : F("rfbOFF"), id});
 
@@ -1186,7 +1193,7 @@ void rfbForget(unsigned char id, bool status) {
     // we send these in bulk is at the very start of the connection
 #if WEB_SUPPORT
     wsPost([id](JsonObject& root) {
-        _rfbWebSocketSendCodeArray(root, id, 1);
+        _rfbWebSocketSendCodeArray(root, id, 1ul);
     });
 #endif
 
diff --git a/code/espurna/rfbridge.h b/code/espurna/rfbridge.h
index eac7a667..a6eed9e1 100644
--- a/code/espurna/rfbridge.h
+++ b/code/espurna/rfbridge.h
@@ -19,13 +19,13 @@ BrokerDeclare(RfbridgeBroker, void(unsigned char protocol, const char* code));
 void rfbSend(const char* code);
 void rfbSend(const String& code);
 
-void rfbStatus(unsigned char id, bool status);
-void rfbLearn(unsigned char id, bool status);
+void rfbStatus(size_t id, bool status);
+void rfbLearn(size_t id, bool status);
 
-String rfbRetrieve(unsigned char id, bool status);
-void rfbStore(unsigned char id, bool status, const char * code);
+String rfbRetrieve(size_t id, bool status);
+void rfbStore(size_t id, bool status, const char* code);
 
-void rfbForget(unsigned char id, bool status);
+void rfbForget(size_t id, bool status);
 void rfbSetup();
 
 #endif // RFB_SUPPORT == 1
diff --git a/code/espurna/settings.cpp b/code/espurna/settings.cpp
index cfdcbf12..fd42dcd0 100644
--- a/code/espurna/settings.cpp
+++ b/code/espurna/settings.cpp
@@ -211,33 +211,39 @@ String settingsQueryDefaults(const String& key) {
     return String();
 }
 
-settings_move_key_t _moveKeys(const String& from, const String& to, unsigned char index) {
+settings_move_key_t _moveKeys(const String& from, const String& to, size_t index) {
     return settings_move_key_t {{from, index}, {to, index}};
 }
 
 void moveSetting(const String& from, const String& to) {
-    const auto value = getSetting(from);
-    if (value.length() > 0) setSetting(to, value);
+    auto result = settings::kv_store.get(from);
+    if (result) {
+        setSetting(to, result.ref());
+    }
     delSetting(from);
 }
 
 void moveSetting(const String& from, const String& to, unsigned char index) {
     const auto keys = _moveKeys(from, to, index);
-    const auto value = getSetting(keys.first);
-    if (value.length() > 0) setSetting(keys.second, value);
+
+    auto result = settings::kv_store.get(keys.first.value());
+    if (result) {
+        setSetting(keys.second, result.ref());
+    }
 
     delSetting(keys.first);
 }
 
 void moveSettings(const String& from, const String& to) {
-    unsigned char index = 0;
-    while (index < 100) {
+    for (size_t index = 0; index < 100; ++index) {
         const auto keys = _moveKeys(from, to, index);
-        const auto value = getSetting(keys.first);
-        if (value.length() == 0) break;
-        setSetting(keys.second, value);
+        auto result = settings::kv_store.get(keys.first.value());
+        if (!result) {
+            break;
+        }
+
+        setSetting(keys.second, result.ref());
         delSetting(keys.first);
-        ++index;
     }
 }
 
@@ -516,7 +522,7 @@ void _settingsInitCommands() {
                 continue;
             }
 
-            ctx.output.printf("> %s => \"%s\"\n", key.c_str(), result.value.c_str());
+            ctx.output.printf("> %s => \"%s\"\n", key.c_str(), result.c_str());
         }
 
         terminalOK(ctx);
diff --git a/code/espurna/settings_embedis.h b/code/espurna/settings_embedis.h
index 2a1dfb3f..8e3f33d5 100644
--- a/code/espurna/settings_embedis.h
+++ b/code/espurna/settings_embedis.h
@@ -489,11 +489,9 @@ class KeyValueStore {
 
             auto key_result = kv.key.read();
             if (key_result == key) {
-                if (read_value) {
-                    out = std::move(kv.value.read();
-                } else {
-                    out = String();
-                }
+                out = read_value
+                    ? std::move(kv.value.read())
+                    : String();
                 break;
             }
         } while (_state != State::End);
diff --git a/code/espurna/thingspeak.cpp b/code/espurna/thingspeak.cpp
index 203502bb..d27fa3a8 100644
--- a/code/espurna/thingspeak.cpp
+++ b/code/espurna/thingspeak.cpp
@@ -50,7 +50,7 @@ const char THINGSPEAK_REQUEST_TEMPLATE[] PROGMEM =
 bool _tspk_enabled = false;
 bool _tspk_clear = false;
 
-char * _tspk_queue[THINGSPEAK_FIELDS] = {NULL};
+String _tspk_fields[THINGSPEAK_FIELDS];
 String _tspk_data;
 
 bool _tspk_flush = false;
@@ -136,14 +136,11 @@ void _tspkConfigure() {
     #endif
 }
 
-void _tspkClearQueue() {
+void _tspkClearFields() {
     _tspk_tries = THINGSPEAK_TRIES;
     if (_tspk_clear) {
-        for (unsigned char id=0; id<THINGSPEAK_FIELDS; id++) {
-            if (_tspk_queue[id] != NULL) {
-                free(_tspk_queue[id]);
-                _tspk_queue[id] = NULL;
-            }
+        for (size_t id = 0; id < THINGSPEAK_FIELDS; ++id) {
+            _tspk_fields[id] = "";
         }
     }
 }
@@ -153,7 +150,7 @@ void _tspkRetry(int code) {
         _tspk_flush = true;
         DEBUG_MSG_P(PSTR("[THINGSPEAK] Re-enqueuing %u more time(s)\n"), _tspk_tries);
     } else {
-        _tspkClearQueue();
+        _tspkClearFields();
     }
 }
 
@@ -369,11 +366,11 @@ void _tspkPost(const String& address) {
 
 #endif // THINGSPEAK_USE_ASYNC
 
-void _tspkEnqueue(unsigned char index, const char * payload) {
-    DEBUG_MSG_P(PSTR("[THINGSPEAK] Enqueuing field #%u with value %s\n"), index, payload);
-    --index;
-    if (_tspk_queue[index] != NULL) free(_tspk_queue[index]);
-    _tspk_queue[index] = strdup(payload);
+void _tspkEnqueue(size_t index, const char* payload) {
+    if (index > 0) {
+        DEBUG_MSG_P(PSTR("[THINGSPEAK] Enqueuing field #%hhu with value %s\n"), index, payload);
+        _tspk_fields[--index] = payload;
+    }
 }
 
 void _tspkFlush() {
@@ -390,11 +387,11 @@ void _tspkFlush() {
     _tspk_data.reserve(tspkDataBufferSize);
 
     // Walk the fields, numbered 1...THINGSPEAK_FIELDS
-    for (unsigned char id=0; id<THINGSPEAK_FIELDS; id++) {
-        if (_tspk_queue[id] != NULL) {
+    for (size_t id = 0; id<THINGSPEAK_FIELDS; id++) {
+        if (_tspk_fields[id].length()) {
             if (_tspk_data.length() > 0) _tspk_data.concat("&");
             char buf[32] = {0};
-            snprintf_P(buf, sizeof(buf), PSTR("field%u=%s"), (id + 1), _tspk_queue[id]);
+            snprintf_P(buf, sizeof(buf), PSTR("field%u=%s"), (id + 1), _tspk_fields[id].c_str());
             _tspk_data.concat(buf);
         }
     }
@@ -411,14 +408,17 @@ void _tspkFlush() {
 
 // -----------------------------------------------------------------------------
 
-bool tspkEnqueueRelay(unsigned char index, bool status) {
-    if (!_tspk_enabled) return true;
-    unsigned char id = getSetting({"tspkRelay", index}, 0);
-    if (id > 0) {
-        _tspkEnqueue(id, status ? "1" : "0");
-        return true;
+bool tspkEnqueueRelay(size_t index, bool status) {
+    if (_tspk_enabled) {
+        unsigned char id = getSetting({"tspkRelay", index}, 0);
+        if (id > 0) {
+            _tspkEnqueue(id, status ? "1" : "0");
+            return true;
+        }
+        return false;
     }
-    return false;
+
+    return true;
 }
 
 bool tspkEnqueueMeasurement(unsigned char index, const char * payload) {
diff --git a/code/espurna/thingspeak.h b/code/espurna/thingspeak.h
index 6b8e2c0d..3517548c 100644
--- a/code/espurna/thingspeak.h
+++ b/code/espurna/thingspeak.h
@@ -12,7 +12,7 @@ Copyright (C) 2019 by Xose Pérez <xose dot perez at gmail dot com>
 
 constexpr size_t tspkDataBufferSize { 256ul };
 
-bool tspkEnqueueRelay(unsigned char index, bool status);
+bool tspkEnqueueRelay(size_t index, bool status);
 bool tspkEnqueueMeasurement(unsigned char index, const char * payload);
 void tspkFlush();
 
diff --git a/code/espurna/tuya.cpp b/code/espurna/tuya.cpp
index 8f280b1e..b43f26fc 100644
--- a/code/espurna/tuya.cpp
+++ b/code/espurna/tuya.cpp
@@ -139,7 +139,7 @@ namespace tuya {
             }
         }
 
-        void channel(unsigned char channel, float value) override {
+        void channel(size_t channel, float value) override {
             // XXX: can't handle channel values when OFF, and will turn the lights ON
             if (!_last_state) {
                 return;
@@ -520,7 +520,7 @@ error:
 
     namespace build {
 
-    constexpr unsigned char channelDpId(unsigned char index) {
+    constexpr unsigned char channelDpId(size_t index) {
         return (index == 0) ? TUYA_CH1_DPID :
             (index == 1) ? TUYA_CH2_DPID :
             (index == 2) ? TUYA_CH3_DPID :
@@ -528,7 +528,7 @@ error:
             (index == 4) ? TUYA_CH5_DPID : 0u;
     }
 
-    constexpr unsigned char switchDpId(unsigned char index) {
+    constexpr unsigned char switchDpId(size_t index) {
         return (index == 0) ? TUYA_SW1_DPID :
             (index == 1) ? TUYA_SW2_DPID :
             (index == 2) ? TUYA_SW3_DPID :
@@ -551,7 +551,7 @@ error:
 
     void setupSwitches() {
         bool done { false };
-        for (unsigned char id = 0; id < RelaysMax; ++id) {
+        for (size_t id = 0; id < RelaysMax; ++id) {
             auto dp = getSetting({"tuyaSwitch", id}, build::switchDpId(id));
             if (!dp) {
                 break;
@@ -577,7 +577,7 @@ error:
 
     void setupChannels() {
         bool done { false };
-        for (unsigned char id = 0; id < Light::ChannelsMax; ++id) {
+        for (size_t id = 0; id < Light::ChannelsMax; ++id) {
             auto dp = getSetting({"tuyaChannel", id}, build::channelDpId(id));
             if (!dp) {
                 break;
diff --git a/code/espurna/utils.cpp b/code/espurna/utils.cpp
index cd5b6f09..27c64a51 100644
--- a/code/espurna/utils.cpp
+++ b/code/espurna/utils.cpp
@@ -11,6 +11,18 @@ Copyright (C) 2017-2019 by Xose Pérez <xose dot perez at gmail dot com>
 #include "board.h"
 #include "ntp.h"
 
+bool tryParseId(const char* p, TryParseIdFunc limit, size_t& out) {
+    static_assert(std::numeric_limits<size_t>::max() >= std::numeric_limits<unsigned long>::max(), "");
+
+    char* endp { nullptr };
+    out = strtoul(p, &endp, 10);
+    if ((endp == p) || (*endp != '\0') || (out >= limit())) {
+        return false;
+    }
+
+    return true;
+}
+
 void setDefaultHostname() {
     if (strlen(HOSTNAME) > 0) {
         setSetting("hostname", F(HOSTNAME));
diff --git a/code/espurna/utils.h b/code/espurna/utils.h
index dc485033..5abc5912 100644
--- a/code/espurna/utils.h
+++ b/code/espurna/utils.h
@@ -52,3 +52,6 @@ double roundTo(double num, unsigned char positions);
 
 size_t hexEncode(const uint8_t* in, size_t in_size, char* out, size_t out_size);
 size_t hexDecode(const char* in, size_t in_size, uint8_t* out, size_t out_size);
+
+using TryParseIdFunc = size_t(*)();
+bool tryParseId(const char* ptr, TryParseIdFunc limit, size_t& out);