light: experiment with relay state provider

* dynamic relays should not overlap with configuration
* prefer explicit relay configuration vs. dynamic addition

resolve #2568

code/espurna/config/general.h

@@ -1214,10 +1214,6 @@
 #define LIGHT_TRANSITION_TIME   500         // Time in millis from color to color
 #endif
 
-#ifndef LIGHT_RELAY_ENABLED
-#define LIGHT_RELAY_ENABLED     1           // Add a virtual switch that controls the global light state. Depends on RELAY_SUPPORT
-#endif
-
 // -----------------------------------------------------------------------------
 // DOMOTICZ
 // -----------------------------------------------------------------------------

code/espurna/config/hardware.h

@@ -827,6 +827,9 @@
     #define DEVICE              "BNSZ01"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // LEDs
     #define LED1_PIN            13
     #define LED1_PIN_INVERSE    1
@@ -876,6 +879,9 @@
     #define DEVICE              "SONOFF_B1"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_MY92XX
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
 
     #define MY92XX_MODEL        MY92XX_MODEL_MY9231
@@ -900,6 +906,9 @@
     #define DEVICE              "SONOFF_LED"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // LEDs
     #define LED1_PIN            13
     #define LED1_PIN_INVERSE    1
@@ -1304,6 +1313,9 @@
     #define DEVICE              "AI_LIGHT"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_MY92XX
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define MY92XX_MODEL        MY92XX_MODEL_MY9291
     #define MY92XX_CHIPS        1
@@ -1323,6 +1335,9 @@
     #define DEVICE              "RGB_LED"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_MY92XX
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define MY92XX_MODEL        MY92XX_MODEL_MY9291
     #define MY92XX_CHIPS        1
@@ -1342,6 +1357,9 @@
     #define DEVICE              "LED_CONTROLLER"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // LEDs
     #define LED1_PIN            2
     #define LED1_PIN_INVERSE    1
@@ -1365,6 +1383,9 @@
     #define DEVICE              "LED_CONTROLLER_20"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // LEDs
     #define LED1_PIN            2
     #define LED1_PIN_INVERSE    1
@@ -1388,6 +1409,9 @@
     #define DEVICE              "ZJ_WFMN_A_11"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // LEDs
     #define LED1_PIN            2
     #define LED1_PIN_INVERSE    1
@@ -1413,6 +1437,9 @@
     #define DEVICE              "ZJ_WFMN_B_11"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // LEDs
     #define LED1_PIN            2
     #define LED1_PIN_INVERSE    1
@@ -1437,6 +1464,9 @@
     #define DEVICE              "ZJ_WFMN_C_11"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Buttons
     #define BUTTON1_PIN         0
     #define BUTTON1_CONFIG      BUTTON_PUSHBUTTON | BUTTON_DEFAULT_HIGH
@@ -1456,6 +1486,9 @@
     #define DEVICE              "ZJ_ESPM_5CH_B_13"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Buttons
     #define BUTTON1_PIN         0
     #define BUTTON1_CONFIG      BUTTON_PUSHBUTTON | BUTTON_DEFAULT_HIGH
@@ -1479,6 +1512,9 @@
     #define DEVICE              "ZJ_LB_RGBWW_L"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define LIGHT_CH1_PIN       5       // RED
     #define LIGHT_CH2_PIN       4       // GREEN
@@ -1497,6 +1533,9 @@
     #define DEVICE              "H801"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Debug
     #define UART1_TX_PIN        2
     #define UART2_RX_PIN        GPIO_NONE
@@ -1519,6 +1558,9 @@
     #define DEVICE              "H802"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Debug
     #define UART1_TX_PIN        2
     #define UART2_RX_PIN        GPIO_NONE
@@ -1906,6 +1948,9 @@
     #define DEVICE              "QUINLED"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // LEDs
     #define LED1_PIN            5
     #define LED1_PIN_INVERSE    1
@@ -1925,6 +1970,9 @@
     #define DEVICE              "AL_LC01"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define LIGHT_CH1_PIN       5       // RED
     #define LIGHT_CH2_PIN       12      // GREEN
@@ -1937,6 +1985,9 @@
     #define DEVICE              "AL_LC02"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define LIGHT_CH1_PIN       12      // RED
     #define LIGHT_CH2_PIN       5       // GREEN
@@ -1950,6 +2001,9 @@
     #define DEVICE              "AL_LC02_V14"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define LIGHT_CH1_PIN       14      // RED
     #define LIGHT_CH2_PIN       5       // GREEN
@@ -1963,6 +2017,9 @@
     #define DEVICE              "AL_LC06"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Buttons
     #define BUTTON1_PIN         0
     #define BUTTON1_CONFIG      BUTTON_PUSHBUTTON | BUTTON_DEFAULT_HIGH
@@ -1982,6 +2039,9 @@
     #define DEVICE              "AL_LC11"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define LIGHT_CH1_PIN       5       // RED
     #define LIGHT_CH2_PIN       4       // GREEN
@@ -1996,6 +2056,9 @@
     #define DEVICE              "E27"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_MY92XX
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define MY92XX_MODEL        MY92XX_MODEL_MY9291
     #define MY92XX_CHIPS        1
@@ -2064,6 +2127,9 @@
     #define DEVICE              "LYT8266"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define LIGHT_CH1_PIN       13      // RED
     #define LIGHT_CH2_PIN       12      // GREEN
@@ -2079,6 +2145,9 @@
     #define DEVICE              "WITTY_CLOUD"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Buttons
     #define BUTTON1_PIN         4
     #define BUTTON1_CONFIG      BUTTON_PUSHBUTTON | BUTTON_DEFAULT_HIGH
@@ -3708,6 +3777,9 @@
     #define DEVICE                      "AG_L4"
     #define LIGHT_PROVIDER              LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER             RELAY_PROVIDER_LIGHT_STATE
+
     // button 1: "power" button
     #define BUTTON1_PIN                 4
     #define BUTTON1_RELAY               1
@@ -3749,6 +3821,9 @@
     #define DEVICE                      "AG_L4_V3"
     #define LIGHT_PROVIDER              LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER             RELAY_PROVIDER_LIGHT_STATE
+
     // button 1: "power" button
     #define BUTTON1_PIN                 13
     #define BUTTON1_RELAY               1
@@ -4298,8 +4373,10 @@
     #define BUTTON1_RELAY               1
 
     // Relays
-    #define RELAY1_PIN                  15
-    #define RELAY1_TYPE                 RELAY_TYPE_NORMAL
+    #define RELAY1_PROVIDER             RELAY_PROVIDER_LIGHT_STATE
+
+    #define RELAY2_PIN                  15
+    #define RELAY2_TYPE                 RELAY_TYPE_NORMAL
 
     // LEDs
     //Red   LED: 0
@@ -4522,6 +4599,9 @@
     #define DEVICE              "RGBW_CONTROLLER"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // LEDs
     #define LED1_PIN            13
     #define LED1_PIN_INVERSE    1
@@ -4597,6 +4677,7 @@
     #define TUYA_CH1_DPID       2
 
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_CUSTOM
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_NONE
 
     #define LED1_GPIO           14
 
@@ -4728,6 +4809,9 @@
     #define DEVICE              "MIOBULB001"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define LIGHT_CH1_PIN       14      // RED
     #define LIGHT_CH2_PIN       12      // GREEN
@@ -4857,6 +4941,9 @@
     #define DEVICE              "SMART_LED_LIGHT_STRIP"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light RGBW
     #define LIGHT_CH1_PIN       4       // RED
     #define LIGHT_CH2_PIN       12      // GREEN
@@ -5073,6 +5160,9 @@
     #define DEVICE              "E27_7W_RGBW"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define LIGHT_CH1_PIN       4       // RED
     #define LIGHT_CH2_PIN       12      // GREEN
@@ -5091,6 +5181,9 @@
     #define DEVICE              "GU53_RGBWW"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define LIGHT_CH1_PIN       4       // RED
     #define LIGHT_CH2_PIN       12      // GREEN
@@ -5109,6 +5202,9 @@
     #define DEVICE              "E27_10W_WHITE"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define LIGHT_CH1_PIN       5       // WARM WHITE
     #define LIGHT_CH2_PIN       4       // COLD WHITE
@@ -5127,6 +5223,9 @@
     #define DEVICE              "GENIO_W_A60"
     #define LIGHT_PROVIDER      LIGHT_PROVIDER_DIMMER
 
+    // Relay
+    #define RELAY1_PROVIDER     RELAY_PROVIDER_LIGHT_STATE
+
     // Light
     #define LIGHT_CH1_PIN       14       // WHITE
 

code/espurna/config/types.h

@@ -106,6 +106,7 @@
 #define RELAY_PROVIDER_GPIO         RelayProvider::Gpio
 #define RELAY_PROVIDER_DUAL         RelayProvider::Dual
 #define RELAY_PROVIDER_STM          RelayProvider::Stm
+#define RELAY_PROVIDER_LIGHT_STATE  RelayProvider::LightState
 
 #define RFB_PROVIDER_RCSWITCH       0
 #define RFB_PROVIDER_EFM8BB1        1

code/espurna/config/version.h

@@ -21,5 +21,5 @@
 #endif
 
 #ifndef CFG_VERSION
-#define CFG_VERSION             13
+#define CFG_VERSION             14
 #endif

code/espurna/ifan.cpp

@@ -324,7 +324,9 @@ void setup() {
     if (relay_pin) {
         auto provider = std::make_unique<FanProvider>(
             std::move(relay_pin), config, state_pins, onFanSpeedUpdate);
-        if (!relayAdd(std::move(provider))) {
+
+        const auto result = relayAdd(std::move(provider));
+        if (result) {
             DEBUG_MSG_P(PSTR("[IFAN] Could not add relay provider for GPIO%d\n"), controlPin());
             gpioUnlock(controlPin());
         }

code/espurna/light.cpp

@@ -65,10 +65,6 @@ namespace build {
 
 constexpr float WhiteFactor { LIGHT_WHITE_FACTOR };
 
-constexpr bool relay() {
-    return 1 == LIGHT_RELAY_ENABLED;
-}
-
 constexpr bool color() {
     return 1 == LIGHT_USE_COLOR;
 }
@@ -287,10 +283,6 @@ String mqttGroup() {
     return getSetting("mqttGroupColor");
 }
 
-bool relay() {
-    return getSetting("ltRelay", build::relay());
-}
-
 bool color() {
     return getSetting("useColor", build::color());
 }
@@ -364,34 +356,10 @@ espurna::duration::Milliseconds saveDelay() {
 
 #if RELAY_SUPPORT
 
-// Setup virtual relays contolling the light's state
-// TODO: only do per-channel setup optionally
-
-class LightChannelProvider : public RelayProviderBase {
-public:
-    LightChannelProvider() = delete;
-    explicit LightChannelProvider(size_t id) :
-        _id(id)
-    {}
-
-    const char* id() const override {
-        return "light_channel";
-    }
-
-    void change(bool status) override {
-        lightState(_id, status);
-        lightState(true);
-        lightUpdate();
-    }
-
-private:
-    size_t _id { RelaysMax };
-};
-
-class LightGlobalProvider : public RelayProviderBase {
+class LightStateProvider : public RelayProviderBase {
 public:
-    const char* id() const override {
-        return "light_global";
+    espurna::StringView id() const override {
+        return STRING_VIEW("light-state");
     }
 
     void change(bool status) override {
@@ -706,7 +674,6 @@ auto _light_report_delay = espurna::light::build::reportDelay();
 std::forward_list<LightReportListener> _light_report;
 LightTimerValue<int> _light_report_timer(0);
 
-bool _light_has_controls = false;
 bool _light_has_cold_white = false;
 bool _light_has_warm_white = false;
 bool _light_has_color = false;
@@ -2330,10 +2297,7 @@ void _lightMqttCallback(unsigned int type, espurna::StringView topic, espurna::S
 
         mqttSubscribe(MQTT_TOPIC_CHANNEL "/+");
         mqttSubscribe(MQTT_TOPIC_BRIGHTNESS);
-
-        if (!_light_has_controls) {
-            mqttSubscribe(MQTT_TOPIC_LIGHT);
-        }
+        mqttSubscribe(MQTT_TOPIC_LIGHT);
 
         if (_light_has_color) {
             mqttSubscribe(MQTT_TOPIC_COLOR_RGB);
@@ -2447,10 +2411,7 @@ void lightMQTT() {
     }
 
     mqttSend(MQTT_TOPIC_BRIGHTNESS, _light_brightness.toString().c_str());
-
-    if (!_light_has_controls) {
-        mqttSend(MQTT_TOPIC_LIGHT, _light_state ? "1" : "0");
-    }
+    mqttSend(MQTT_TOPIC_LIGHT, _light_state ? "1" : "0");
 }
 
 void lightMQTTGroup() {
@@ -2585,19 +2546,17 @@ void _lightApiSetup() {
         }
     );
 
-    if (!_light_has_controls) {
-        apiRegister(F(MQTT_TOPIC_LIGHT),
-            [](ApiRequest& request) {
-                request.send(lightState() ? "1" : "0");
-                return true;
-            },
-            [](ApiRequest& request) {
-                _lightParsePayload(request.param(F("value")));
-                lightUpdate();
-                return true;
-            }
-        );
-    }
+    apiRegister(F(MQTT_TOPIC_LIGHT),
+        [](ApiRequest& request) {
+            request.send(lightState() ? "1" : "0");
+            return true;
+        },
+        [](ApiRequest& request) {
+            _lightParsePayload(request.param(F("value")));
+            lightUpdate();
+            return true;
+        }
+    );
 }
 
 } // namespace
@@ -2672,11 +2631,6 @@ void _lightWebSocketOnConnected(JsonObject& root) {
     root["ltSaveDelay"] = _light_save_delay.count();
     root["ltTime"] = _light_transition_time.count();
     root["ltStep"] = _light_transition_step.count();
-#if RELAY_SUPPORT
-    root["ltRelay"] = espurna::light::settings::relay();
-#else
-    root["ltRelay"] = false;
-#endif
 }
 
 void _lightWebSocketOnAction(uint32_t client_id, const char* action, JsonObject& data) {
@@ -3523,24 +3477,6 @@ void _lightConfigure() {
     }
 }
 
-#if RELAY_SUPPORT
-
-void _lightRelayBoot() {
-    if (_light_has_controls) {
-        return;
-    }
-
-    auto next_id = relayCount();
-    if (relayAdd(std::make_unique<LightGlobalProvider>())) {
-        _light_state_listener = [next_id](bool state) {
-            relayStatus(next_id, state);
-        };
-        _light_has_controls = true;
-    }
-}
-
-#endif
-
 void _lightBoot() {
     const size_t Channels { _light_channels.size() };
     if (Channels) {
@@ -3640,12 +3576,30 @@ void _lightSettingsMigrate(int version) {
         moveSetting("lightColdMired", "ltColdMired");
         moveSetting("lightWarmMired", "ltWarmMired");
     }
+
+    if (version < 14) {
+        delSetting(F("ltRelay"));
+    }
 }
 
 } // namespace
 
 // -----------------------------------------------------------------------------
 
+RelayProviderBasePtr lightMakeStateRelayProvider(size_t id) {
+#if RELAY_SUPPORT
+    if (!_light_state_listener) {
+        _light_state_listener = [id](bool state) {
+            relayStatus(id, state);
+        };
+
+        return std::make_unique<LightStateProvider>();
+    }
+#endif
+
+    return nullptr;
+}
+
 void lightSetup() {
     migrateVersion(_lightSettingsMigrate);
 
@@ -3701,12 +3655,6 @@ void lightSetup() {
 
     _lightBoot();
 
-#if RELAY_SUPPORT
-    if (espurna::light::settings::relay()) {
-        _lightRelayBoot();
-    }
-#endif
-
     #if WEB_SUPPORT
         wsRegister()
             .onVisible(_lightWebSocketOnVisible)

code/espurna/light.h

@@ -278,4 +278,7 @@ void lightOnReport(LightReportListener);
 void lightSetProvider(std::unique_ptr<LightProvider>&&);
 bool lightAdd();
 
+class RelayProviderBase;
+std::unique_ptr<RelayProviderBase> lightMakeStateRelayProvider(size_t);
+
 void lightSetup();

code/espurna/lightfox.cpp

@@ -257,8 +257,8 @@ void setup() {
 #endif
 
     for (size_t relay = 0; relay < build::relays(); ++relay) {
-        size_t relayId { relayCount() };
-        if (!relayAdd(std::make_unique<RelayProvider>(relayId))) {
+        const auto result = relayAdd(std::make_unique<RelayProvider>(relay));
+        if (!result) {
             break;
         }
     }

code/espurna/relay.cpp

@@ -16,6 +16,7 @@ Copyright (C) 2019-2021 by Maxim Prokhorov <prokhorov dot max at outlook dot com
 #include "relay.h"
 #include "rpc.h"
 #include "rtcmem.h"
+#include "light.h"
 #include "settings.h"
 #include "storage_eeprom.h"
 #include "terminal.h"
@@ -31,6 +32,50 @@ Copyright (C) 2019-2021 by Maxim Prokhorov <prokhorov dot max at outlook dot com
 
 // -----------------------------------------------------------------------------
 
+enum class RelayBoot {
+    Off,
+    On,
+    Same,
+    Toggle,
+    LockedOff,
+    LockedOn
+};
+
+enum class RelayLock {
+    None,
+    Off,
+    On
+};
+
+enum class RelayType {
+    Normal,
+    Inverse,
+    Latched,
+    LatchedInverse
+};
+
+enum class RelayMqttTopicMode {
+    Normal,
+    Inverse
+};
+
+enum class RelayProvider {
+    None,
+    Dummy,
+    Gpio,
+    Dual,
+    Stm,
+    LightState,
+};
+
+enum class RelaySync {
+    None,
+    ZeroOrOne,
+    JustOne,
+    All,
+    First
+};
+
 namespace espurna {
 namespace relay {
 namespace flood {
@@ -597,13 +642,15 @@ PROGMEM_STRING(RelayProviderDummy, "dummy");
 PROGMEM_STRING(RelayProviderGpio, "gpio");
 PROGMEM_STRING(RelayProviderDual, "dual");
 PROGMEM_STRING(RelayProviderStm, "stm");
+PROGMEM_STRING(RelayProviderLightState, "light-state");
 
-static constexpr std::array<Enumeration<RelayProvider>, 5> RelayProviderOptions PROGMEM {
+static constexpr std::array<Enumeration<RelayProvider>, 6> RelayProviderOptions PROGMEM {
     {{RelayProvider::None, RelayProviderNone},
-     {RelayProvider::Dummy, RelayProviderDummy},
-     {RelayProvider::Gpio, RelayProviderGpio},
-     {RelayProvider::Dual, RelayProviderDual},
-     {RelayProvider::Stm, RelayProviderStm}}
+    {RelayProvider::Dummy, RelayProviderDummy},
+    {RelayProvider::Gpio, RelayProviderGpio},
+    {RelayProvider::Dual, RelayProviderDual},
+    {RelayProvider::Stm, RelayProviderStm},
+    {RelayProvider::LightState, RelayProviderLightState}}
 };
 
 PROGMEM_STRING(RelayTypeNormal, "normal");
@@ -998,8 +1045,8 @@ static constexpr espurna::settings::query::IndexedSetting IndexedSettings[] PROG
 // No-op provider, available for purely virtual relays that are controlled only via API
 
 struct DummyProvider : public RelayProviderBase {
-    const char* id() const override {
-        return "dummy";
+    espurna::StringView id() const override {
+        return espurna::relay::settings::options::RelayProviderDummy;
     }
 
     void change(bool) override {
@@ -1229,8 +1276,8 @@ struct GpioProvider : public RelayProviderBase {
         _reset_pin(std::move(reset_pin))
     {}
 
-    const char* id() const override {
-        return "gpio";
+    espurna::StringView id() const override {
+        return espurna::relay::settings::options::RelayProviderGpio;
     }
 
     bool setup() override {
@@ -1301,8 +1348,8 @@ public:
             _instances.end());
     }
 
-    const char* id() const override {
-        return "dual";
+    espurna::StringView id() const override {
+        return espurna::relay::settings::options::RelayProviderDual;
     }
 
     bool setup() override {
@@ -1412,10 +1459,11 @@ public:
         _id(id)
     {}
 
-    const char* id() const override {
-        return "stm";
+    espurna::StringView id() const override {
+        return espurna::relay::settings::options::RelayProviderStm;
     }
 
+
     bool setup() override {
         static bool once = ([]() {
             const auto port = uartPort(RELAY_PROVIDER_STM_PORT - 1);
@@ -2570,8 +2618,9 @@ String _relayTristateToPayload(T value) {
 }
 
 void _relayPrint(Print& out, const Relay& relay, size_t index) {
-    out.printf_P(PSTR("relay%u {Prov=%s TargetStatus=%s CurrentStatus=%s Lock=%s}\n"),
-        index, relay.provider->id(),
+    out.printf_P(PSTR("relay%u {Prov=%.*s TargetStatus=%s CurrentStatus=%s Lock=%s}\n"),
+        index,
+        relay.provider->id().length(), relay.provider->id().begin(),
         relay.target_status ? "on" : "off",
         relay.current_status ? "on" : "off",
         _relayTristateToPayload(relay.lock).c_str());
@@ -2860,19 +2909,29 @@ RelayProviderBasePtr _relaySetupProvider(size_t index) {
     case RelayProvider::Dummy:
         result = std::make_unique<DummyProvider>();
         break;
+
     case RelayProvider::Gpio:
         result = _relayGpioProvider(index, type);
         break;
+
     case RelayProvider::Stm:
 #if RELAY_PROVIDER_STM_SUPPORT
         result = std::make_unique<StmProvider>(index);
 #endif
         break;
+
     case RelayProvider::Dual:
 #if RELAY_PROVIDER_DUAL_SUPPORT
         result = std::make_unique<DualProvider>(index);
 #endif
         break;
+
+    case RelayProvider::LightState:
+#if LIGHT_PROVIDER != LIGHT_PROVIDER_NONE
+        result = lightMakeStateRelayProvider(index);
+#endif
+        break;
+
     case RelayProvider::None:
         break;
     }
@@ -2976,17 +3035,31 @@ void relaySetup() {
 
 }
 
-bool relayAdd(RelayProviderBasePtr&& provider) {
-    if (provider && provider->setup()) {
-        _relays.emplace_back(std::move(provider));
-        espurnaRegisterOnceUnique([]() {
-            _relayConfigure();
-            _relayBootAll();
-        });
-        return true;
+RelayAddResult relayAdd(RelayProviderBasePtr&& provider) {
+    RelayAddResult out;
+
+    const auto id = _relays.size();
+    if (espurna::relay::settings::provider(id) != RelayProvider::None) {
+        return out;
     }
 
-    return false;
+    if (!provider) {
+        return out;
+    }
+
+
+    if (!provider->setup()) {
+        return out;
+    }
+
+    out.id = id;
+    _relays.emplace_back(std::move(provider));
+    espurnaRegisterOnceUnique([]() {
+        _relayConfigure();
+        _relayBootAll();
+    });
+
+    return out;
 }
 
 #endif // RELAY_SUPPORT == 1

code/espurna/relay.h

@@ -18,49 +18,6 @@ Copyright (C) 2016-2019 by Xose Pérez <xose dot perez at gmail dot com>
 
 constexpr size_t RelaysMax { 32ul };
 
-enum class RelayBoot {
-    Off,
-    On,
-    Same,
-    Toggle,
-    LockedOff,
-    LockedOn
-};
-
-enum class RelayLock {
-    None,
-    Off,
-    On
-};
-
-enum class RelayType {
-    Normal,
-    Inverse,
-    Latched,
-    LatchedInverse
-};
-
-enum class RelayMqttTopicMode {
-    Normal,
-    Inverse
-};
-
-enum class RelayProvider {
-    None,
-    Dummy,
-    Gpio,
-    Dual,
-    Stm
-};
-
-enum class RelaySync {
-    None,
-    ZeroOrOne,
-    JustOne,
-    All,
-    First
-};
-
 class RelayProviderBase {
 public:
     RelayProviderBase() = default;
@@ -79,7 +36,7 @@ public:
     virtual void change(bool status) = 0;
 
     // unique id of the provider
-    virtual const char* id() const = 0;
+    virtual espurna::StringView id() const = 0;
 };
 
 PayloadStatus relayParsePayload(espurna::StringView);
@@ -113,7 +70,15 @@ void relaySave(bool persist);
 using RelayStatusCallback = void(*)(size_t id, bool status);
 using RelayProviderBasePtr = std::unique_ptr<RelayProviderBase>;
 
-bool relayAdd(RelayProviderBasePtr&& provider);
+struct RelayAddResult {
+    size_t id { RelaysMax };
+
+    explicit operator bool() const {
+        return id != RelaysMax;
+    }
+};
+
+RelayAddResult relayAdd(RelayProviderBasePtr&& provider);
 void relayOnStatusNotify(RelayStatusCallback);
 void relayOnStatusChange(RelayStatusCallback);
 

code/html/custom.css

@@ -614,15 +614,13 @@ input::placeholder {
 }
 
 #light-cct,
-#light-picker,
-#light-state {
+#light-picker {
     display: none;
 }
 
 #light.light-cct #light-cct,
 #light.light-cct:not(.light-white) #light-channel-c,
 #light.light-cct:not(.light-white) #light-channel-w,
-#light.light-color.light-on:not(.light-cct) #light-picker,
-#light.light-state #light-state {
+#light.light-color.light-on:not(.light-cct) #light-picker {
     display: block;
 }

code/html/custom.js

@@ -2170,12 +2170,6 @@ function colorUpdate(mode, value) {
     }
 }
 
-function lightStateEnabled(value) {
-    if (!value) {
-        lightAddClass("light-state");
-    }
-}
-
 function initLightState() {
     const toggle = document.getElementById("light-state-value");
     toggle.addEventListener("change", (event) => {
@@ -2643,10 +2637,6 @@ function processData(data) {
             return;
         }
 
-        if ("ltRelay" === key) {
-            lightStateEnabled(value);
-        }
-
         if ("useWhite" === key) {
             whiteEnabled(value);
         }

code/html/index.html

@@ -632,14 +632,6 @@
 
                             <fieldset>
 
-                                <div class="pure-control-group module module-relay">
-                                    <label>Light state switch</label>
-                                    <div><input type="checkbox" name="ltRelay"></div>
-                                    <span class="pure-form-message">
-                                        Add a virtual relay switch that controls the ON / OFF state.
-                                    </span>
-                                </div>
-
                                 <div class="pure-control-group">
                                     <label>Save values</label>
                                     <div><input type="checkbox" name="ltSave"></div>