Use NEOPIXEL as case light

Add an option to use the NEOPIXEL LED as case light.

.travis.yml

@@ -94,7 +94,7 @@ script:
   - opt_enable REPRAP_DISCOUNT_SMART_CONTROLLER SDSUPPORT EEPROM_SETTINGS
   - opt_enable BLINKM PCA9632 RGB_LED NEOPIXEL_LED
   - opt_enable AUTO_BED_LEVELING_LINEAR Z_MIN_PROBE_REPEATABILITY_TEST DEBUG_LEVELING_FEATURE SKEW_CORRECTION SKEW_CORRECTION_FOR_Z SKEW_CORRECTION_GCODE
-  - opt_enable_adv FWRETRACT MAX7219_DEBUG LED_CONTROL_MENU
+  - opt_enable_adv FWRETRACT MAX7219_DEBUG LED_CONTROL_MENU CASE_LIGHT_ENABLE CASE_LIGHT_USE_NEOPIXEL
   - opt_set ABL_GRID_POINTS_X 16
   - opt_set ABL_GRID_POINTS_Y 16
   - opt_set_adv FANMUX0_PIN 53

Marlin/Configuration_adv.h

@@ -243,6 +243,10 @@
   #define CASE_LIGHT_DEFAULT_ON true          // Set default power-up state on
   #define CASE_LIGHT_DEFAULT_BRIGHTNESS 105   // Set default power-up brightness (0-255, requires PWM pin)
   //#define MENU_ITEM_CASE_LIGHT              // Add a Case Light option to the LCD main menu
+  //#define CASE_LIGHT_USE_NEOPIXEL           // Use Neopixel LED as case light, requires NEOPIXEL_LED.
+  #if ENABLED(CASE_LIGHT_USE_NEOPIXEL)
+    #define CASE_LIGHT_NEOPIXEL_COLOR { 255, 255, 255, 255 } // { Red, Green, Blue, White }
+  #endif
 #endif
 
 //===========================================================================

Marlin/Marlin_main.cpp

@@ -10608,26 +10608,44 @@ inline void gcode_M907() {
 #endif // HAS_MICROSTEPS
 
 #if HAS_CASE_LIGHT
+
   #ifndef INVERT_CASE_LIGHT
     #define INVERT_CASE_LIGHT false
   #endif
   uint8_t case_light_brightness;  // LCD routine wants INT
   bool case_light_on;
 
+  #if ENABLED(CASE_LIGHT_USE_NEOPIXEL)
+    LEDColor case_light_color =
+      #ifdef CASE_LIGHT_NEOPIXEL_COLOR
+        CASE_LIGHT_NEOPIXEL_COLOR
+      #else
+        { 255, 255, 255, 255 }
+      #endif
+    ;
+  #endif
+
   void update_case_light() {
-    pinMode(CASE_LIGHT_PIN, OUTPUT); // digitalWrite doesn't set the port mode
-    if (case_light_on) {
+    const uint8_t i = case_light_on ? case_light_brightness : 0, n10ct = INVERT_CASE_LIGHT ? 255 - i : i;
+
+    #if ENABLED(CASE_LIGHT_USE_NEOPIXEL)
+
+      leds.set_color(
+        MakeLEDColor(case_light_color.r, case_light_color.g, case_light_color.b, case_light_color.w, n10ct),
+        false
+      );
+
+    #else // !CASE_LIGHT_USE_NEOPIXEL
+
+      SET_OUTPUT(CASE_LIGHT_PIN);
       if (USEABLE_HARDWARE_PWM(CASE_LIGHT_PIN))
-        analogWrite(CASE_LIGHT_PIN, INVERT_CASE_LIGHT ? 255 - case_light_brightness : case_light_brightness);
-      else
-        WRITE(CASE_LIGHT_PIN, INVERT_CASE_LIGHT ? LOW : HIGH);
-    }
-    else {
-      if (USEABLE_HARDWARE_PWM(CASE_LIGHT_PIN))
-        analogWrite(CASE_LIGHT_PIN, INVERT_CASE_LIGHT ? 255 : 0);
-      else
-        WRITE(CASE_LIGHT_PIN, INVERT_CASE_LIGHT ? HIGH : LOW);
-    }
+        analogWrite(CASE_LIGHT_PIN, n10ct);
+      else {
+        const bool s = case_light_on ? !INVERT_CASE_LIGHT : INVERT_CASE_LIGHT;
+        WRITE(CASE_LIGHT_PIN, s ? HIGH : LOW);
+      }
+
+    #endif // !CASE_LIGHT_USE_NEOPIXEL
   }
 #endif // HAS_CASE_LIGHT
 

Marlin/SanityCheck.h

@@ -1621,6 +1621,10 @@ static_assert(COUNT(sanity_arr_3) <= XYZE_N, "DEFAULT_MAX_ACCELERATION has too m
   #error "LED_CONTROL_MENU requires an LCD controller."
 #endif
 
+#if ENABLED(CASE_LIGHT_USE_NEOPIXEL) && DISABLED(NEOPIXEL_LED)
+  #error "CASE_LIGHT_USE_NEOPIXEL requires NEOPIXEL_LED."
+#endif
+
 #if ENABLED(SKEW_CORRECTION)
   #if !defined(XY_SKEW_FACTOR) && !(defined(XY_DIAG_AC) && defined(XY_DIAG_BD) && defined(XY_SIDE_AD))
     #error "SKEW_CORRECTION requires XY_SKEW_FACTOR or XY_DIAG_AC, XY_DIAG_BD, XY_SIDE_AD."

Marlin/leds.h

@@ -70,6 +70,21 @@ typedef struct LEDColor {
       #endif
     #endif
   {}
+  LEDColor(const uint8_t (&rgbw)[4]) : r(rgbw[0]), g(rgbw[1]), b(rgbw[2])
+    #if HAS_WHITE_LED
+      , w(rgbw[3])
+      #if ENABLED(NEOPIXEL_LED)
+        , i(NEOPIXEL_BRIGHTNESS)
+      #endif
+    #endif
+  {}
+  LEDColor& operator=(const uint8_t (&rgbw)[4]) {
+    r = rgbw[0]; g = rgbw[1]; b = rgbw[2];
+    #if HAS_WHITE_LED
+      w = rgbw[3];
+    #endif
+    return *this;
+  }
   LEDColor& operator=(const LEDColor &right) {
     if (this != &right) memcpy(this, &right, sizeof(LEDColor));
     return *this;