Blowing Out A Candle Flicker LED: The Death Of Flame

One day there will be no more need for flames. [slider2732] has put yet another nail in the coffin of this most ancient of all technology by making a candle that uses a flicker LED that you blow out. A little more miniaturization and we’ll have them fully integrated into the size of birthday cake candles (Hint hint, hackers!).

You may have seen these candle flicker LEDs.  They have a small chip inside them that modulates the LED’s light to flicker like a candle. We’ve even reported on what [Cpldcpu] found when he reverse engineered them first here and then here.

What [slider2732] did was to buy an electronic candle that used one of the LEDs actually shaped like a flame, and to drill a hole near the ‘flame’. He them embedded a microphone behind the hole. That goes to an LM386 amplifier circuit and from there to an Arduino Pro Mini all powered by a LiPo. As you’d expect, the Arduino code is very simple, just watch the pin from the amplifier and based on an internal variable, turn the LED on or off. We really like how none of the electronics is visible and how you actually have to lean over and blow into the top of the candle to blow it out. You can see this demonstrated in the video below.

To light the LED again he makes it so that blowing on the LED while it’s off will turn it back on again. To us old schoolers, that seems a little odd so we’d like to see an electronic match that lights up when you swipe it against something (with a flicker LED) and that lights the candle’s LED when brought near it. Of course you’d blow out the electronic match too! If you’re not that ambitious then a lighter with flicker LED would work too. Submit it to our tips line when you’re done!

22 thoughts on “Blowing Out A Candle Flicker LED: The Death Of Flame

    1. “We can’t win against obsession. They care, we don’t. They win.” –Douglas Adams

      ‭”Simplicity is a great virtue but it requires hard work to achieve it and education to appreciate it. And to make matters worse: complexity sells better” – Edsger W. Dijkstra

  1. A microphone is one way to go. Another would be a pressure switch, similar to what is in the automatic e-cigarettes. They are extremely tiny, and sensitive to just a light breath.

    1. Came here to say this: while I suppose it’s educational to implement the feature yourself, my parents have had an identical-looking candle with this exact feature sitting in their house for about 10 years now. The only difference is that theirs is powered by button cell batteries instead of a LiPo.

  2. Or use an ldr to light it. Any lightsource can be used that produces a sufficiently bright light and goes from dark to light and back very quickly, which rules out on coming daylight. The led candle fades in slowly emulating a real candle that’s just lit. A fresh one should take longer to light :)

  3. While a nice hack, the author doesn’t seem to mention about the current consumption. And I bet that the Arduino and LM386 draw more then the LED itself, so the battery will be flat very soon even if you remember to turn it off.

  4. If you want LED birthday candles, you need tiny batteries. There were styli for PalmOS PDAs that had an LED flashlight on the top, yet were small enough to fit into the stylus storage holes. Dunno what battery they used but it was replaceable and really small diameter.

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