Support for neopixel RGBW rings

[walkerdb]

The extra "white" LED in each pixel on the RGBW neopixel rings seem to be throwing off LED indexing on the python bindings.

Expected behavior:

Calling setPixelColor on each pixel index with 11111111 for each color should set the RGB values of that pixel to max brightness.

Actual behavior:

Index 0 correctly sets RGB of the first pixel Index 1 sets the white LED of the first pixel along with the RG LEDs of the second. Index 2 sets BW of the second pixel and only G of the third

etc.

The following code replicates this behavior:

strip = Adafruit_NeoPixel(16, 18, 800000, 10, False, 10, 0)
strip.begin()

green = '11111111'
red = '11111111'
blue = '11111111'
color = int(green + red + blue, 2)

strip.setPixelColor(0, color)  # RGB pixel 1
strip.setPixelColor(1, color)  # W pixel 1, RG pixel 2
strip.setPixelColor(2, color)  # BW pixel 2, G pixel 3
strip.show()

Currently running on an rPi Zero WH with NeoPixel Ring 16 x 5050 RGBW LEDs (datasheet here)

If I had to venture a guess it looks a lot like an off-by-one error somewhere, almost like it's missing an extra byte for each pixel.

[penfold42]

I didn’t see you set the strip type

https://github.com/jgarff/rpi_ws281x/blob/master/python/examples/SK6812_strandtest.py

[walkerdb]

That was 100% it. Didn't realize that was a feature!

Thanks for the help.