Hi everyone, I'm working on an installation and I need to clarify some things

Domain_Admin · November 12, 2014, 4:11pm

Hi everyone, I’m working on an installation and I need to clarify some things about RGB leds on the way.

I need to create a safe color pallete that would allow me to randomly select one of the colors and be confident that the color selected will be shown on the LED stripe of WS2801 leds as similar as possible with the colors that i will be showing on a web Interface.
Should I guide myself with a small set of colors like:
http://assets.ecopowertech.com/images/products/rgb_controller_72w_large.jpg
Or could I do a ring like http://static.ikfsolutions1.com/files/shops/brightlightz/products/scrolling-rgb-controller_xxxlarge.jpg

Any comments or suggestions will be very appreciated.

Mark_Kriegsman · November 12, 2014, 4:37pm

As you might imagine I have sever thoughts, but let me just say these:

it’s actually super hard to actually match screen colors to LED colors. And harder still to match LED colors to colors printed on dials or controls. Just really hard to do it automatically.
you could hand-match a bunch colors (10? 20?) and make pairs of “what it looks like on screen” and “what to display on LEDs that matches well”
if you did that, you could then probably interpolate between them. It occurs to me now that you could make a Palette of 16 colors for screen and a corresponding one for LEDs, and let the palette code do the interpolation between them

Could you say more about how your system will work and how you envision it being used?

Domain_Admin · November 12, 2014, 5:35pm

Thank’s Mark for the fast reply; https://vimeo.com/111337039 as you may see on that video I’m designing a system where users can send a color to the LED arrangment and then get another color back.
Those colors come from the UI on mobile node.js app that sents goodWill messages to a xmas tree, so after u compose a new msg and select a color for it you can send it to the tree and see how it climbs to the top with your color and msg and after that you will see a different color coming down and receiving a random message on your phone with that color as background or so.

I’m almost ready with all the system, but the illusion of magic will be complete only if the colors that go up/down on the tree are somehow close to the ones you are seing on the app.
If I have to select a small group of colors like the chinese RGB led control it would be fine, but I need to know if I could do it better with something like the RGB ring that i showed on the second image of my post.

regards.

Mark_Kriegsman · November 12, 2014, 7:28pm

So in general RGB colors on a ring like that (which are pure hues) work pretty well for color matching, especially if you use FastLED’s “setCorrection( …)” for your led strips. Try setCorrection(TypicalLEDStrip).

The place where color matching is much harder is when the colors are desaturated (pastels)

I bet you could use a circle-of-pure-hues and get “magical” results.

I really like this project idea!

Garth_Bushell · November 12, 2014, 9:18pm

I have a project on my to do list that uses the colorhug to try to calibrate the led strip automatically. Not sure if this is a valid thing to do with a colorimeter but thought it was maybe worth a try. There is a command line tool that could be easily wrapped with a simple python script that could change led strip on remote target and see what the colorhug reports.

Adam_bluebottleyello · May 24, 2015, 3:06pm

I found it is easier to just add 3 pods to control rgb and then manually set color you want… not sure it’s what you are looking for though