Command ``SetOption117 1`` for light fading to be fixed duration instead of fixed slew rate (#10109)

CHANGELOG.md

@@ -17,6 +17,7 @@ All notable changes to this project will be documented in this file.
 - Support for SPI connected MFRC522 13.56MHz rfid card reader (#9916)
 - Letsencrypt R3 in addition to X3 CA (#10086)
 - Zigbee add visual map of network
+- Command ``SetOption117 1`` for light fading to be fixed duration instead of fixed slew rate (#10109)
 
 ### Breaking Changed
 - KNX DPT9 (16-bit float) to DPT14 (32-bit float) by Adrian Scillato (#9811, #9888)

tasmota/settings.h

@@ -142,7 +142,7 @@ typedef union {                            // Restricted by MISRA-C Rule 18.4 bu
     uint32_t mqtt_switches : 1;            // bit 0 (v9.0.0.3)   - SetOption114 - (Switch) Detach Switches from relays and enable MQTT action state for all the SwitchModes (1)
     uint32_t mi32_enable : 1;              // bit 1 (v9.1.0.1)   - SetOption115 - (ESP32 BLE) Enable ESP32 MI32 BLE (1)
     uint32_t zb_disable_autoquery : 1;     // bit 2 (v9.1.0.1)   - SetOption116 - (Zigbee) Disable auto-query of zigbee lights and devices (1)
-    uint32_t spare03 : 1;                  // bit 3
+    uint32_t fade_fixed_duration : 1;      // bit 3 (v9.1.0.2)   - SetOption117 - (Light) run fading at fixed duration instead of fixed slew rate
     uint32_t spare04 : 1;                  // bit 4
     uint32_t spare05 : 1;                  // bit 5
     uint32_t spare06 : 1;                  // bit 6

tasmota/xdrv_04_light.ino

@@ -2137,7 +2137,10 @@ bool LightApplyFade(void) {   // did the value chanegd and needs to be applied
       // compute the duration of the animation
       // Note: Settings.light_speed is the number of half-seconds for a 100% fade,
       // i.e. light_speed=1 means 1024 steps in 500ms
-      Light.fade_duration = (distance * Settings.light_speed * 500) / 1023;
+      Light.fade_duration = Settings.light_speed * 500;
+      if (!Settings.flag5.fade_fixed_duration) {
+        Light.fade_duration = (distance * Light.fade_duration) / 1023;    // time is proportional to distance, except with SO117
+      }
       if (Settings.save_data) {
         // Also postpone the save_data for the duration of the Fade (in seconds)
         uint32_t delay_seconds = 1 + (Light.fade_duration + 999) / 1000;   // add one more second