Neat article.

I'd love to know more about how candle-flicker LEDs are assembled, because that source of [apparent] randomness is very interesting to me. I'm not sure if it's an LFSR or true HRNG, and I'm sure there are lots of different designs out there for the simulcrum of natural candle light.

You can get a better sense of their operation if you wire up the LED to an audio circuit where they'll make a pleasingly happy beep boop sound.

(Edit: There was an article somewhere that explored the entropy and concluded that their component operated on a LFSR, as they binned all the brightness outputs into integer values and waves hands did fancy math to conclude that the brightness it was likely modulated by a LFSR. I'll see if I can find it.)

(Edit 2: https://cpldcpu.com/2013/12/08/hacking-a-candleflicker-led/ here's that article for those interested. https://news.ycombinator.com/item?id=25530895 was the original submission to HN.)

De-doming these things (as discussed in another comment) is quite a chore; I de-domed 30 LEDs (candle-flicker, of course) in order to diffuse the light and fit under the keys of a small 3x10 keyboard I was building. But the effect is neat when the backlight is on as it almost looks like a shadow is randomly typing away as the entire array flickers.