Customising LED light strips.

After soliciting and receiving excellent advice on tools for setting up and programming LED strips, I can now create pleasing patterns of my own choosing and cover the ceiling with them. Getting this up and running was more wire stripping and soldering than I expected, but the software side was relatively easy.

It turns out that it's an interesting challenge to write soothing patterns that are interesting but don't have blinky or subtle jerky motions. You have to map a continuous function with no rapid changes in value to the LED strip or you will notice the individual LEDs blinking in not-so-soothing ways. You also get blinkiness at very low brightnesses due to the quantization of LED brightness values, so it's important to avoid that as well. Humans also seem sensitive to overly orderly patterns as being tacky an a bit unpleasant, so it was important to make the patterns feel organic and constantly varying instead of stuck in a fixed loop.

The short version of what I did:

• Pixelblaze V3 is a great controller; I got one plus the 8-channel expander.
• For LEDs you have a choice between:
  -- NeoPixel: Has good RGBWW options, which means it actually looks good when you want light that's white or close to white. Otherwise it has a slower update speed that makes it harder for patterns to look pleasing, and you can notice occasional glitches in updates that are irritating to some people.
  -- DotStar: Has very high update rates, and (I believe) finer control of brightness, so you don't get the jerkiness associated with a lot of LED animations, but there aren't good RGBWW options yet.
• I went with the BTF lighting RGBWW NeoPixel strip and got a monstrous 200W power supply to drive 10m of it.
• For the pattern, I set up three waves that had different periods that were relatively prime so that direct repetition was rare, and various formulas composed of values from these waves controlled brightness and hue over the length of the strip.