Disable onboard LED when LEDs are not in use (#1245)

* Disable onboard LED when LEDs are not in use

* Remove unused variable

* Only disable onboard LED if LEDPIN == LED_BUILTIN

* Change LEDPIN to LED_BUILTIN

wled00/FX.h

@@ -650,6 +650,7 @@ class WS2812FX {
     void handle_palette(void);
 
     bool
+      shouldStartBus = false,
       _useRgbw = false,
       _skipFirstMode,
       _triggered;

wled00/FX_fcn.cpp

@@ -396,6 +396,18 @@ void WS2812FX::setBrightness(uint8_t b) {
     {
       _segments[i].setOption(SEG_OPTION_FREEZE, false);
     }
+    #if LEDPIN == LED_BUILTIN
+      if (!shouldStartBus)
+        shouldStartBus = true;
+    #endif
+  } else {
+    #if LEDPIN == LED_BUILTIN
+      if (shouldStartBus) {
+        shouldStartBus = false;
+        const uint8_t ty = _useRgbw ? 2 : 1;
+        bus->Begin((NeoPixelType)ty, _lengthRaw);
+      }
+    #endif
   }
   if (SEGENV.next_time > millis() + 22 && millis() - _lastShow > MIN_SHOW_DELAY) show();//apply brightness change immediately if no refresh soon
 }

wled00/button.cpp

@@ -95,9 +95,15 @@ void handleIO()
     }
   } else if (millis() - lastOnTime > 600)
   {
-    #if RLYPIN >= 0
+     if (!offMode) {
-     if (!offMode) digitalWrite(RLYPIN, !RLYMDE);
+      #if LEDPIN == LED_BUILTIN
+        pinMode(LED_BUILTIN, OUTPUT);
+        digitalWrite(LED_BUILTIN, HIGH);
       #endif
+      #if RLYPIN >= 0
+       digitalWrite(RLYPIN, !RLYMDE);
+      #endif
+     }
     offMode = true;
   }