A few ago I may have accidentally bought a ring of 12 RGB LEDs; I soldered temporary leads on it, connected it to a CircuitPython supported board and played around for a while.

They we had a couple of friends come over to remote FOSDEM together, and I had talked with one of them about WS2812 / NeoPixels, so I brought them to the living room, in case there was a chance to show them in sort-of-use.

Then I was dealing with playing the various streams as we moved from one room to the next, which lead to me being called "video team", which lead to me wearing a video team shirt (from an old DebConf, not FOSDEM, but still video team), which lead to somebody asking me whether I also had the sheet with the countdown to the end of the talk, and the answer was sort-of-yes (I should have the ones we used to use for our Linux Day), but not handy.

But I had a thing with twelve things in a clock-like circle.

A bit of fiddling on the CircuitPython REPL resulted, if I remember correctly, in something like:

import board
import neopixel
import time

num_pixels = 12

pixels = neopixel.NeoPixel(board.GP0, num_pixels)
pixels.brightness = 0.1

def end(min):
    pixels.fill((0, 0, 0))
    for i in range(12):
        pixels[i] = (127 + 10 * i, 8 * (12 - i), 0)
        pixels[i-1] = (0, 0, 0)
        time.sleep(min * 5)  # min * 60 / 12

Now, I wasn't very consistent in running end, especially since I wasn't sure whether I wanted to run it at the beginning of the talk with the full duration or just in the last 5 - 10 minutes depending of the length of the slot, but I've had at least one person agree that the general idea has potential, so I'm taking these notes to be able to work on it in the future.

One thing that needs to be fixed is the fact that with the ring just attached with temporary wires and left on the table it isn't clear which LED is number 0, so it will need a bit of a case or something, but that's something that can be dealt with before the next fosdem.

And I should probably add some input interface, so that it is self-contained and not tethered to a computer and run from the REPL.

(And then I may also have a vague idea for putting that ring into some wearable thing: good thing that I actually bought two :D )