Candle technology hasn't changed much in thousands of years — you add to a wax-soaked wick, and it provides light for hours. It's simple, it's effective, and it doesn't need an upgrade.
To be fair to Keith from Keith's Test Garage, he didn't spend every one of them on the internet spent three years redesigning the candle from the ground up with digital guts — while managing to preserve his old-school usability. waking moment of the past three years obsessively engineering and perfecting his candle. It was a low-priority side project that would occasionally dive back into when needed a distraction.
That was the easier part, however, if there were no shortage of believable LED-based candles on the market right now. Keith got a couple of steps farther by first adding a carefully calibrated infrared sensor that could detect the presence of a match when placed inside the candle, allowing the LEDs to be illuminated the same way as light and real candle. But the best feature is a vegetable glycerin-soaked fiberglass wick that produces a quick puff of smoke when zapped with a few volts. It's triggered by a microphone that detects when someone blows on the candle, so only the LEDs turn off, but the candle also produces a satisfying trail of wispy smoke that drifts away.
It's overkill, yes, and overkill for the sake or just seeing if it was at all possible. But if you want to add a little atmosphere to your home, without the risk of burning it to the ground, this is essentially the vape of candles, letting you safely get your mood-enhancing fix.
[Keith’s Test Garage via Hackaday]