SK6812RGBW has R & G reversed

[edalquist]

Not sure if this is a library issue or an issue with my specific LEDs.

I have a set of these: https://www.amazon.com/gp/product/B01HXOJ4HU/

I have to swap the R & G values when I call strip.Color:

strip.Color(0, 255, 0), // red
strip.Color(255, 0, 0), // green
strip.Color(0, 0, 255), // blue
strip.Color(0, 0, 0, 255) // white

[technobly]

That strip you linked to is not RGBW, but rather RGB only if it's truly SK6812 and not SK6812RGBW. They should be the same as WS2812B type.

Try

#define PIXEL_TYPE WS2812B

[edalquist]

It has all 4 LEDs. Setting strip.Color(255, 255, 255) lights all 3 RGB LEDs, strip.Color(0, 0, 0, 255) lights the one W LED and strip.Color(255, 255, 255, 255) lights all 4 LEDs

I'll give WS2812B a try when I get home just to confirm.

[technobly]

Ok interesting. I created the SK6812RGBW pixel type support with an Adafruit RGBW 24 pixel ring and I'm sure I would have tested the color order. Referencing the datasheet, it says RGBW order which is the same as the code.

It's possible you have a knock off or just a different version and the colors need to be swapped. It would probably be best to incorporate the different pixel color arrangements as in the original library:
https://github.com/adafruit/Adafruit_NeoPixel/blob/master/Adafruit_NeoPixel.h#L52-L89

We would have to do it a bit differently though, since we skewed away from the 400kHz vs 800kHz speed settings and opted for direct pixel type mapping. It would work the same though, like

// IMPORTANT: Set pixel COUNT, PIN and TYPE
#define PIXEL_COUNT 10
#define PIXEL_PIN D2
#define PIXEL_TYPE WS2812B
#define PIXEL_COLOR NEO_GRBW

// Parameter 1 = number of pixels in strip
//               note: for some stripes like those with the TM1829, you
//                     need to count the number of segments, i.e. the
//                     number of controllers in your stripe, not the number
//                     of individual LEDs!
// Parameter 2 = pin number (most are valid)
//               note: if not specified, D2 is selected for you.
// Parameter 3 = pixel type [ WS2812, WS2812B, WS2812B2, WS2811,
//                             TM1803, TM1829, SK6812RGBW ]
//               note: if not specified, WS2812B is selected for you.
//               note: RGB order is automatically applied to WS2811,
//                     WS2812/WS2812B/WS2812B2/TM1803 is GRB order.
//
// 800 KHz bitstream 800 KHz bitstream (most NeoPixel products
//               WS2812 (6-pin part)/WS2812B (4-pin part)/SK6812RGBW (RGB+W) )
//
// 400 KHz bitstream (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
//                   (Radio Shack Tri-Color LED Strip - TM1803 driver
//                    NOTE: RS Tri-Color LED's are grouped in sets of 3)

Adafruit_NeoPixel strip = Adafruit_NeoPixel(PIXEL_COUNT, PIXEL_PIN, PIXEL_COLOR + PIXEL_TYPE);

[edalquist]

So I checked with a friend that is using the same strips and they are GRB pixels. This issue can be closed and I'll poke around to see if I can make those changes work (and send a pull request if I do).