Trying to get slow and smooth transitions at the low end of the brightness

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1

Trying to get slow and smooth transitions at the low end of the brightness range. 8 bit color resolution really sucks. Avoiding any RGB part to go lower than 1 limits the pain but the price is a lack of contrast.

Since we have some really fast LED chipsets - has anyone ever written a temporal dithering in order to get some extra bits for the color resolution?
Example: 10 bits would mean 2 extra bits. The possible brightness range of one 8 bit color (0-255) would be extended to 0-1023. Which would mean that we have 3 extra steps between 0 and 1 (of 255). The price would be to get only one quarter of the framrate. For setups that run in the kfps range that should be no problem.

One step further: What about a 10 bit temporal dithering that runs in the background in order to achive a decent gamma correction while we could keep the 8 bit math?

How hard would it be to utilize FastLEDs existing temporal dithering at full brightness in order to soften the brightness steps at the lower end?

Any thoughts?

2

Making use of the existing temporal dithering with 16-bit CRGB objects is part of the plan for the rgbw/rgb16 work when I get back to working on the library.

3

I did this one once: https://gist.github.com/kasperkamperman/4461a70dd0841f80ddf4

4

If you use the APA102 chips you can use the GBC. See: https://github.com/embedded-creations/apa102-gbctest/blob/master/apa102-gbctest.ino

5

That example isn’t documented well and the code isn’t efficient. There’s more in this long thread: https://community.particle.io/t/smartmatrix-apa102-library-open-hardware-photon-apa102-shield/21562

6

Great, thanks for the input everyone!