Yukon and LED Strips

Support
1

Hi,

Brand new to Yukon. Bought the starter kit. I had some LED strips so I thought I would start with those using the “single_strip” example.

The RGB strip works fine using the NEOPIXEL library.

The RGBW strip lights up but I cannot make sense of what I am seeing. Instead of seeing the the same as the RGB strip, I seeing a pattern of LEDS in threes. For instance I can get GREEN, BLUE and RED with the WHITE shifting slowly from the RED led, to the GREEN led and so forth.

The RGBW strip was described as “SK6812 (similar to WS2812B)”. It has power, ground and data.

Do RGBW strips need a different library?

If so, where can I find one?

Thanks much.

Frederick

2

So it looks like this isn’t implemented at the moment. The LED Strip module reference notes that it makes use of the Plasma module, which does support RGBW, but it looks like the LED Strip module code doesn’t have a parameter to tell it you’re using RGBW LEDs. What you’re probably seeing is odd effects of passing RGBW data to something which only expects RGB data.

1 Like
3

Thanks for the reply.

Frederick

4

Hi @fcwilt ,

As Shoe correctly identified, the underlying Plasma library supports RGBW LED strips, but I never got around to exposing that through the LED Strip module itself.

I’ve just gone ahead and added this. Just update the led_strip.py file on your Yukon with the changes shown here ( Support for RGBW LED strips and different color orders by ZodiusInfuser · Pull Request #19 · pimoroni/yukon · GitHub ):

Then in your script where you create the LEDStripModule, add the last line:

module = LEDStripModule(STRIP_TYPE,     # Create a LEDStripModule object, with the details of the attached strip(s)
                        STRIP_PIO,
                        STRIP_SM,
                        LEDS_PER_STRIP,
                        BRIGHTNESS,
                        rgbw=True)

If you could give this a test and let me know it works, then I will merge the code into the main Yukon build.

Edit: To control the white element, you’d do something like:

module.strip.set_rgb(led, r, g, b, w)
5

Hi,

Just saw your message. Working on making the changes now.

I’ve done something wrong as I am getting an error.

Will find and fix and test.

Frederick

6

Found a typo.

Tested and I can now control the white LEDs.

Thanks and good work.

Frederick

1 Like