The technology of candles has not changed much for thousands of years: you add fire to a wick soaked in wax and you get light for hours. It's simple, efficient and requires no upgrades. So of course, someone on the Internet has spent three years redrawing the candle from scratch, with digital courage – all while managing to preserve its old-world friendliness.
To be fair to Keith's Keith's Garage Test, he has not spent all the waking moments of the past three years perfecting and perfecting his candle. It was a low priority secondary project in which he sometimes plunged when he needed a fun distraction. That said, the attention to detail and realistic functionality of the digital candle reflect the time it took to do it.
Powered by an Arduino Pro Mini concealed in a glass container and camouflaged with wax, the candle uses six highly random independent LEDs, allowing them to twinkle and adjust their brightness randomly. The overall effect is that of a real bouncing flame.
This is the easiest part, however, because there is no shortage of credible LED-based candles on the market at the moment. Keith took a few steps further by first adding a carefully calibrated infrared sensor, capable of detecting the presence of a lit match when placed inside the candle, thereby illuminating the LEDs. the same way you light a real candle. But the best feature is a wick of vegetable fiberglass soaked in glycerin that produces a quick puff of smoke when zapped with a few volts. It is triggered by a microphone that detects the moment when someone blows on the candle. Thus, not only do the lights go out, but the candle also produces a satisfying trail of vaporous smoke that dissipates.
It's exaggerated, yes, and exaggerated to see if it was possible. But if you want to add a little ambiance to your home, without the risk of burning it, it's essentially the vape of candles, allowing you to safely get your dose of improvement of your mood.[Keith’s Test Garage via Hackaday]