New led string to play with. SK6812 - rgbw

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chad
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New led string to play with. SK6812 - rgbw

Post by chad »

Hello all. I ordered a new string of led's for a project I want to start. They are like the ws2812 rgb's but they also have a white.
I did a search on the forum and didn't see anything come up. Does any one have a driver? Or can the led string driver be tweaked to work with these?

Here is the data sheet( I think).
http://www.normandled.com/upload/201805 ... asheet.pdf

This is the string.
https://www.amazon.com/dp/B079ZRLMQR?ps ... ct_details

Thanks,
Chad

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Re: New led string to play with. SK6812 - rgbw

Post by Benj »

Hi Chad,

It looks like it should be compatible.

Have a go and let us know how you get on.

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Re: New led string to play with. SK6812 - rgbw

Post by chad »

Ok I'll give it a go. Just wasn't sure how a three channel control component is going to behave with a four channel led.

They should be here today.

Thanks,
Chad

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Re: New led string to play with. SK6812 - rgbw

Post by chad »

Ok so it is sort of working. I tried first with some (should be) good R-G-B ws2812's. And they respond and I can control the color of them. The problem it seems that the start is shifted from 1. If i try #1 it starts at like 16? I think there is something funky with the rgb 2811 / / / component.

I then tried my new R-G-B-White strip and it does respond also offset from 1 but it is more or less impossible to control because there are 4 colors instead of three so everything is off and one led intensity control bleeds into another led.

Suggestions welcome.

thanks
chad

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Re: New led string to play with. SK6812 - rgbw

Post by Benj »

Hi Chad.

I looked at the datasheet on the driver ic sk6812 and there were only three colour channels. Is the white led part of the same led package or a separate package? Do you have a datasheet for the white led?

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Re: New led string to play with. SK6812 - rgbw

Post by chad »

Hi Ben,

Yes They are in the same package , RGBW. So the white channel is just number 4 in the data packet.
I couldn't find a datasheet for the white led yet but I will keep looking.

This is a data sheet from adafruit.
https://cdn-shop.adafruit.com/product-f ... sheet+.pdf

Here is their version using the same chip.
https://www.adafruit.com/product/2867

Thanks,
Chad
They make RGB,RGBWW. WW is warm white. So that is 4 channels in a package.
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Re: New led string to play with. SK6812 - rgbw

Post by chad »

Hi Ben, any new news?

Thanks,
Chad

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Re: New led string to play with. SK6812 - rgbw

Post by mnf »

Hi Chad,

Just had an experiment with one of these. They take a 32bit value using the same timing as ws2812 leds.

I modified my ATTiny85 ws2812 code to take a 32bit colour (note the ws2812 component has 24 bit color - no white - so would need modifying to have a 32 bit buffer. Here I just 'push' values)

Here I'm using a Uno (16MHz as per ATTiny though) - so I can also output info to UART. The LED pin is hardcoded as B0 (pin 8 ) - but I used this code as I knew the timing is 'spot on'.

Works fine - white value is just shifted in as the fourth byte (So GRBW I think...)

I only soldered up one LED (working on that SMD technique) - amazingly worked first time! The final 'switch option' should be 4 (currently 5) if you want to see the chip 'all in'.

Martin
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Re: New led string to play with. SK6812 - rgbw

Post by chad »

Hi Martin, Thank you very much! I will play with this later and let you know.
I am using a pic32mz for my little project so we will see how it goes.

Chad

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Re: New led string to play with. SK6812 - rgbw

Post by mnf »

Hi Chad,

Won't work as is then... The source for the ws2812 component is on the forum @ viewtopic.php?f=76&t=22045&hilit=ws2812 - along with my refresh code which should be easier to modify.

Basically need to extend the data transmitted to 32bits (which will make the refresh slower) - see how it goes, and Ill try and tweak my refresh code this evening if you are having trouble..

Martin

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Re: New led string to play with. SK6812 - rgbw

Post by mnf »

And a datasheet (which seems to show the layout as RGBW) https://cdn-shop.adafruit.com/product-f ... _REV01.pdf

To confuse the issue - they are also available in RGB form - which accept 24 bit colour (GRB as per ws2812) https://cdn-shop.adafruit.com/product-f ... sheet+.pdf

The timings required are also different to WS2812 - (for example reset time is 80us instead of 50us) Guess I was lucky that it worked last night....
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Martin

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Re: New led string to play with. SK6812 - rgbw

Post by chad »

Hi Ben,

I noticed that you got this running in FC9. Can you post this to fc8?
I requested this on march 22nd.

Thanks,

Chad

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Re: New led string to play with. SK6812 - rgbw

Post by Benj »

Hi Chad,

I've now added the component into v8 for you.

Let me know how you get on.

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Re: New led string to play with. SK6812 - rgbw

Post by chad »

Great! thanks. I'll try it out tonight!

Chad

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Re: New led string to play with. SK6812 - rgbw

Post by chad »

Hey, I updated my components and it shows up but when I try to add it to a panel it errors with a "failed to add component".

Chad

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Re: New led string to play with. SK6812 - rgbw

Post by Bruno »

Hi Benj and everyone
I bought some led strips with SK6812 - rgbw driver and I installed your component, but it doesn't work for me either.
Can you check what the problem is?

Thank you very much

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Re: New led string to play with. SK6812 - rgbw

Post by chad »

BUMP :)

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Re: New led string to play with. SK6812 - rgbw

Post by Benj »

Hello,

Sorry about the delay and thanks for bumping, this should hopefully be resolved for you now.

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Re: New led string to play with. SK6812 - rgbw

Post by Bruno »

Hi Benj
Great!!
thanks as always for your availability

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Re: New led string to play with. SK6812 - rgbw

Post by chad »

Hi Ben,

Fired up this after you posted it. Seems to work great , thanks!

Chad

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