4 ms·

This was 10-15 years ago. In between they used dedicated ASICS: https://cpldcpu.com/2013/12/08/hacking-a-candleflicker-led/ https://cpldcpu.com/2013/12/08/hac

This was 10-15 years ago. In between they used dedicated ASICS: https://cpldcpu.com/2013/12/08/hacking-a-candleflicker-led/ https://cpldcpu.com/2013/12/08/hacking-a-candleflicker-led/ And more recently simply microcontrollers: https://cpldcpu.com/2024/01/14/revisiting-candle-flicker-leds-now-with-integrated-timer/ https://cpldcpu.com/2024/01/14/revisiting-candle-flicker-led...

kridsdale1 1y ago
What a testament to the might of the global electronic supply chain that entire computers are cheap enough to be in disposable candles. Single use Vape-pens too. Some of those have displays and Bluetooth. Insane.
- epcoa 1y ago
  Just to offer an alternate perspective. While technically a PIC12 is a computer since it has I/O, tiny storage, a PC and an ALU - it’s hard to even think of it in the same category as what most think of as a computer. IMHO the takeaway is more what the bare minimum it takes to be a computer, which isn’t much. (In other terms, a PIC does not meet the DOOM threshold). PICs are so old and rudimentary that they started out as peripheral controllers for “real” computers in the 70s. It turns out you can do some useful embedded stuff with a basic chip, but even the newest of these are on 30 year old semiconductor tech at this point. That may sound jaded, on the other hand I do find mass production of modern level integration and speeds to still be marvelous. And as an EE, the “white” LED in the candle is more interesting than the uC!
- masfuerte 1y ago
  In strings of programmable LED lights every single LED is actually an LED combined with a computer. This allows the LEDs to be addressed individually without loads of wires.
  - progbits 1y ago
    Computer is overselling it a bit. It's a fixed logic latch+shifter. Basically each LED takes first few bytes for itself and shifts out the rest down the chain. Still awesome this is small and cheap enough to put into individual lights of course.
- firefax 1y ago
  single use vapes should be outlawed imho -- it's so wasteful to include both the cart and the "pen" (power delivery) in one package to be thrown away.
alnwlsn 1y ago
Wow, I'm clearly behind on my flickering candle LED technology knowledge. Thanks!
bob1029 1y ago
https://en.wikipedia.org/wiki/Chua%27s_circuit https://en.wikipedia.org/wiki/Chua%27s_circuit
- cpldcpu 1y ago
  Chaotic circuits are neat, but they are actually not random (their output distribution is not uniform or gaussian). And candles are not random either :) btw, slightley related: https://cpldcpu.com/2020/06/15/building-a-chaotic-oscillator/ https://cpldcpu.com/2020/06/15/building-a-chaotic-oscillator...
  - bob1029 1y ago
    > their output distribution is not uniform or gaussian https://www.worldscientific.com/worldscibooks/10.1142/7200#t=aboutBook https://www.worldscientific.com/worldscibooks/10.1142/7200#t... > "More in details, Ando and Graziani demonstrated that the Chua's circuit can be used to generate either a gaussian or a uniform white noise. To do this, they investigate the statistical and spectral characteristics of the signals generated by a Chua's circuit with respect to different values of the parameters α and β. They then applied the x^2 method to determine which set of parameters leads to a signal having the statistical and spectral characteristics more similar to those of either a Gaussian or uniform noise. By using this method, a signal with a Gaussian-like distribution is obtained with a confidence of 95% for this set of parameters: ..." They've got charts of the probability density functions for each that seem reasonable to me.
    - cpldcpu 1y ago
      Nice, I was not aware of that! Quite interesting. Thank you for the source. It seems to be a corner case. As I learned to know them, chaotic circuits have unpredictable cyclic behavior. Chua's circuit typically follows an oscillatory behavior with a double attractor. If true randomness is the goal, it is much easier to use other sources of randomness like avalanche transistors, jitter of ring-oscillators in the analog domain or LFSRs if you are in the digital domain.
  - 1y ago

kridsdale1 1y ago

What a testament to the might of the global electronic supply chain that entire computers are cheap enough to be in disposable candles. Single use Vape-pens too. Some of those have displays and Bluetooth. Insane.

epcoa 1y ago
Just to offer an alternate perspective. While technically a PIC12 is a computer since it has I/O, tiny storage, a PC and an ALU - it’s hard to even think of it in the same category as what most think of as a computer. IMHO the takeaway is more what the bare minimum it takes to be a computer, which isn’t much. (In other terms, a PIC does not meet the DOOM threshold). PICs are so old and rudimentary that they started out as peripheral controllers for “real” computers in the 70s. It turns out you can do some useful embedded stuff with a basic chip, but even the newest of these are on 30 year old semiconductor tech at this point. That may sound jaded, on the other hand I do find mass production of modern level integration and speeds to still be marvelous. And as an EE, the “white” LED in the candle is more interesting than the uC!
masfuerte 1y ago
In strings of programmable LED lights every single LED is actually an LED combined with a computer. This allows the LEDs to be addressed individually without loads of wires.
- progbits 1y ago
  Computer is overselling it a bit. It's a fixed logic latch+shifter. Basically each LED takes first few bytes for itself and shifts out the rest down the chain. Still awesome this is small and cheap enough to put into individual lights of course.
firefax 1y ago
single use vapes should be outlawed imho -- it's so wasteful to include both the cart and the "pen" (power delivery) in one package to be thrown away.

alnwlsn 1y ago

Wow, I'm clearly behind on my flickering candle LED technology knowledge. Thanks!

bob1029 1y ago

https://en.wikipedia.org/wiki/Chua%27s_circuit https://en.wikipedia.org/wiki/Chua%27s_circuit

cpldcpu 1y ago
Chaotic circuits are neat, but they are actually not random (their output distribution is not uniform or gaussian). And candles are not random either :) btw, slightley related: https://cpldcpu.com/2020/06/15/building-a-chaotic-oscillator/ https://cpldcpu.com/2020/06/15/building-a-chaotic-oscillator...
- bob1029 1y ago
  > their output distribution is not uniform or gaussian https://www.worldscientific.com/worldscibooks/10.1142/7200#t=aboutBook https://www.worldscientific.com/worldscibooks/10.1142/7200#t... > "More in details, Ando and Graziani demonstrated that the Chua's circuit can be used to generate either a gaussian or a uniform white noise. To do this, they investigate the statistical and spectral characteristics of the signals generated by a Chua's circuit with respect to different values of the parameters α and β. They then applied the x^2 method to determine which set of parameters leads to a signal having the statistical and spectral characteristics more similar to those of either a Gaussian or uniform noise. By using this method, a signal with a Gaussian-like distribution is obtained with a confidence of 95% for this set of parameters: ..." They've got charts of the probability density functions for each that seem reasonable to me.
  - cpldcpu 1y ago
    Nice, I was not aware of that! Quite interesting. Thank you for the source. It seems to be a corner case. As I learned to know them, chaotic circuits have unpredictable cyclic behavior. Chua's circuit typically follows an oscillatory behavior with a double attractor. If true randomness is the goal, it is much easier to use other sources of randomness like avalanche transistors, jitter of ring-oscillators in the analog domain or LFSRs if you are in the digital domain.
- 1y ago