[HN Gopher] General purpose MCUs built in to LEDs emulate candle...
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General purpose MCUs built in to LEDs emulate candle flicker
Author : pontifk8r
Score : 87 points
Date : 2024-01-28 19:38 UTC (3 hours ago)
(HTM) web link (cpldcpu.wordpress.com)
(TXT) w3m dump (cpldcpu.wordpress.com)
| 082349872349872 wrote:
| Once upon a time, on USENET, someone had a .sig that predicted
| one day computers would be cheap enough they'd come in cereal
| boxes and we'd throw them away.
|
| That day appears to have arrived.
| FirmwareBurner wrote:
| That happened way before. RFID cards for disposable public
| transportation tickets or those music greeting cards.
| mikepurvis wrote:
| At a certain point it's more about the semantics of what a
| "computer" is. I don't know if I'd count an ASIC from a
| musical greeting card, though; and even within general
| purpose devices, microcontrollers vs microprocessors are
| typically delineated by the presence of an MMU.
| kragen wrote:
| the 6502, 8080, z80, 8085, 8086, 65816, 68000, and 68010
| were universally described as microprocessors, not
| microcontrollers, but did not have mmus built in (and of
| these only the 68010 could easily have one bolted on, as i
| understand it)
|
| i think typically the thing that distinguished these from
| microcontrollers like the 8031, 8051, 8748, 8751, pic1650,
| etc., is that the microcontrollers had program memory built
| into them, either rom, eprom, or, starting in the 90s,
| flash. so they didn't need to be booted, they didn't need
| program ram, and in fact for a lot of applications they
| didn't need any external ram at all
| wongarsu wrote:
| If I can program it to execute a sequence of arithmetic and
| logical operations that approximate a Turing machine (with
| a finite band), and reprogram it at a later date to execute
| a different sequence of such operations, that's a computer
| to me. I wouldn't count ASICs, but the PIC12F508 or the
| 3-cent microcontroller referenced in the post definitely
| count.
|
| Though by my definition of requiring reprogrammability and
| Turing completeness I am purposefully excluding many things
| that have historically been considered computers, like the
| many mechanical computers of the 19th and 20th century.
| From that standpoint I can see how some people might count
| ASICs as computers, even if I don't think that fits modern
| usage.
| yau8edq12i wrote:
| The worst offenders right now might be disposable vapes. I saw
| some sold with effing lcd screens built-in. For a disposable
| piece of crap.
| Scoundreller wrote:
| The rechargeable lithium batteries in those really doesn't
| fit the "lithium shortage" and "we don't have enough battery
| capacity to build an EV for everyone" narrative
| jdsully wrote:
| One car has 4,500 cells - bigger cells than most of the
| vapes. So it really is a matter of scale.
| exe34 wrote:
| How many cars does one smoke in a year though?
| aftbit wrote:
| Hopefully zero! Still, if you replace your car (or its
| battery) every 10 years (pretty long IMO) and smoke one
| vape a day (yikes), you'll use more cells on your car
| than your vapes.
| worewood wrote:
| Do not give those guys ideas
| lmm wrote:
| The kind of people who can afford to buy EVs buy a new
| car what, every 3 years? So I guess about 1/3 of a car
| (or, using the numbers from another comment, about 4000
| vapes' worth).
| markstos wrote:
| It does if the vape makers have an underpriced lithium
| source and don't care about the pending lithium shortage.
| Scoundreller wrote:
| they're just buying off-the-shelf cylindrical or flat-
| pack li-ion cells
| tomatotomato37 wrote:
| The lithium in those cheap disposable things are less
| "lithium" and more "metallic powder/paste that
| theoretically contains elements of lithium." It's not
| something you'd want to actually use in anything important
| like a car battery
| jdietrich wrote:
| Not true. "Disposable" vapes use commodity li-ion cells,
| of the same basic type that you'd find in a cellphone, a
| laptop or an EV. They probably aren't the best quality,
| but there's nothing unusual about the chemistry or
| packaging. Li-ion cells are the preferred chemistry
| because of the very high discharge rate - alkaline or
| primary lithium cells just can't deliver enough current.
| The cell is perfectly capable of being recharged, but
| some people prefer the convenience of a disposable device
| and manufacturers are quite happy to respond to that
| demand.
|
| It's wasteful, I don't particularly approve of it, I
| expect to see a lot of jurisdiction ban disposable vapes,
| but nor do I think it's particularly egregious or
| meaningfully impacting on the commodity price of lithium
| carbonate.
|
| https://hackaday.com/2022/05/05/2022-hackaday-prize-
| disposab...
| conradev wrote:
| It actually fits the narrative pretty well
|
| The materials for one EV battery can make ~30 e-bikes, and
| currently EVs are too expensive for most people.
|
| The way to fix that and the way that industry is fixing it
| is to make batteries more efficient (higher-density, new
| anodes/cathodes) in parallel with making a bunch more of
| them (and mining more lithium).
|
| If we succeed in making a $25k EV, the batteries used in
| those vapes will be _even cheaper_.
|
| I don't think it's desirable and I find the waste
| appalling, but I do think that disposable batteries can
| only be expected to grow without intervention.
| jdietrich wrote:
| It takes around 850g of lithium carbonate to produce one
| kWh of lithium batteries. The current market price for
| lithium carbonate is about $14/kg. The base spec Tesla
| Model 3 has a 57.5kWh battery pack, so the lithium in the
| pack represents a cost of ~$685, or just under 2% of the
| list price of the vehicle.
|
| A typical disposable vape contains about five cents worth
| of lithium.
|
| https://www.irena.org/-/media/Files/IRENA/Agency/Technical-
| P...
| graphe wrote:
| I've collected a few of them and they are robust and
| rechargable batteries. A common battery is IP17350 1100mAh
| 4.07Wh (Date of manufacture the one I see on the one I'm
| holding is 20210613). Anyone got any idea to use them besides
| small flashlights? They also have a pressure sensor on the
| LED and a nice metal case pretty often.
| FirmwareBurner wrote:
| I'm waiting for the EU to ban these fucking things already.
| That and disposable power banks. Yes, you read that right.
|
| Selling consumer devices with Li-Ion batteries that are
| designed to not be rechargeable, should be banned altogether.
| rcxdude wrote:
| Interesting thing about li-ion batteries, is they have much
| less lithium in them than disposable lithium coin cell
| batteries, and hold much more charge. If we're outlawing
| disposable li-ions we should outlaw those as well.
| FirmwareBurner wrote:
| _> If we're outlawing disposable li-ions we should outlaw
| those as well._
|
| Except when your watch battery dies, you only dispose of
| the battery, not together with the watch, as is the case
| with those single-use vapes.
| quatrefoil wrote:
| We're OK with disposable alkaline batteries, so what makes
| lithium worse? If anything, alkaline batteries might have a
| slightly worse environmental footprint due to the use of
| manganese.
|
| The problem with lithium batteries is that they can catch
| on fire, but that's a problem only when charged (or
| charging). A fully discharged battery shouldn't do much.
| mschuster91 wrote:
| > We're OK with disposable alkaline batteries, so what
| makes lithium worse?
|
| No we're not. Disposable batteries should not be a thing
| anywhere, especially not in products where they cannot
| easily be removed by design. Alkaline batteries may not
| combust when damaged, but their internal juice leaking
| out is damn corrosive.
|
| > A fully discharged battery shouldn't do much.
|
| Even that is enough to light trash compactor trucks or
| the heaps on waste collection plants to fire. This shit
| is becoming a massive problem for the trash hauler and
| processing industry. One in Australia blames 35 (!) fires
| a day in the country... no surprise if 1.8 million of
| them are sold a week [1]. This is frankly _insane_ , and
| the rise in trash fires directly corresponds with
| disposable vapes.
|
| Additionally, we need every bit of lithium we can get for
| electric vehicles and other stuff. Not for throwaway
| devices.
|
| [1] https://www.abc.net.au/news/2023-12-02/qld-lithium-
| ion-batte...
| pi-rat wrote:
| There's been generic microcontrollers (usually single shot
| programmable) available for less than 3 cent per mcu for half a
| decade already. Check out Padauk and similar MCUs.
| self wrote:
| I searched Google for this recently and could not find it. I
| tried it again on Google Groups just now and found one
| reference to it:
|
| https://groups.google.com/g/comp.arch/c/Y4C_Zjkb9VM/m/scDk_0...
|
| > Killer micros of today are a lot like flourescent lights --
| cheap to operate, prevalent, and expensive to turn off. To see
| a machine standing idle, when you were raised as a child to
| "use cycles efficiently" is a gut-wrenching experience. Just
| remember Alan Kay's prediction: In the future, computers will
| come in cereal boxes and we will throw them away.
|
| March 20, 1990. I haven't found a source for Alan Kay's
| prediction.
| dragontamer wrote:
| At least a decade ago, a major magazine had a disposable chip
| inside for... I don't remember why.
|
| Does anyone remember this?
| sam_bristow wrote:
| It might be a myth, but I seem to remember the ASICs used to
| flicker older LED designs were often repurposed from audio
| greeting cards. The light was actually just Happy Birthday
| playing through an LED or bulb rather than a speaker.
| userbinator wrote:
| Not a myth. I clearly remember watching a YouTube video where
| this was discovered, only a few years ago, but of course the
| uselessness of search engines these days has made it impossible
| to find now.
| marginalia_nu wrote:
| Yeah I think I saw that too, bigclive maybe?
| mrb wrote:
| Here is a 2011 post of someone who discovered that:
| https://www.halloweenforum.com/threads/interesting-fact-
| abou...
|
| And here is someone who recorded audio samples:
| https://www.instructables.com/How-to-Listen-to-Light/
| dmitrygr wrote:
| I hope there is a follow up where the LED is ground down and a
| PICKIT2 is used to read out the code :)
| linker3000 wrote:
| If you want to see some candle flicker code based on a PIC12F508
| or 9 see below.
|
| The flicker effect is based on a linear feedback shift register
| function to provide a pseudo random effect.
|
| https://github.com/linker3000/CandleFlameSim
| huppeldepup wrote:
| Going to drop this here:
|
| "Reverse engineering" a real candle
|
| https://cpldcpu.wordpress.com/2016/01/05/reverse-engineering...
| cmiller1 wrote:
| This is great, I wish I could find off the shelf LED candles
| that more closely approximate the real thing. I'd also like
| them to be taper candles on a little holder with a loop
| finger hole so I can grab it to investigate noises in the
| night.
| userbinator wrote:
| _that probably cost around a cent per die_
|
| I believe it's more like a tenth or hundredth of that, if you're
| talking about USD.
| marssaxman wrote:
| Seems like a small step up from the ubiquitous WS2812, an LED
| with an onboard controller handling PWM and one-wire
| communication.
|
| Years ago, before animated LED christmas lights were readily
| available, I hand-made such a string out of ATtiny85 controllers,
| soldered onto bicolor red/green LEDs, one controller per light. A
| little bit of C and an evolving animation algorithm recycled from
| a previous project yielded a pleasing quasi-rhythmic effect. It
| was absurdly non-economical, but felt like a glimpse of the
| future.
| ThisIsMyAltAcct wrote:
| Some people say software is eating the world but I prefer to say
| its infesting it.
| dist-epoch wrote:
| DNA is software. The world is already full of software. We're
| just catching up.
| kebman wrote:
| I really hate these fake LED candles with a passion. Either put
| an actual candle on the table, or just put a small cosy light
| that doesn't flicker.
| bxparks wrote:
| I like quite them. With LED candles, there's no danger of fires
| if you forget about the candle, or if you accidentally knocking
| them over, or if something accidentally goes over the candle.
| There is no mess to clean up as the candle melts down the wax.
| There is no worry about wind blowing out the candle.
|
| I don't like those small LED candles using disposable
| watch/button batteries. I use ones using standard AA batteries,
| which means I can use NiMH rechargeables.
| graphe wrote:
| Why? Ive known several people that died from candles including
| the actions of other people's usage of candles.
| Hnrobert42 wrote:
| Not to mention that whenever I light a candle, my air filter
| spins up and my air quality monitor says pm2.5 peaks.
| cushychicken wrote:
| Is the actual make and model of the MCU just a guess?
|
| Doesn't seem to be anything to corroborate the PIC12 besides a
| pinout the author has seen before.
|
| Just mention because there are likely a zillion eight pin MCUs
| with this pinout/ballout pattern.
| rgovostes wrote:
| Semi-relatedly, the best "digital candle" app I ever found was
| one that just drew an orange rectangle in the center of an
| otherwise black screen, and animated its scale randomly. This
| convincingly modulates the brightness of the display.
| cperciva wrote:
| Next up: "Porting Doom to run on an LED candle".
| semi-extrinsic wrote:
| FWIW Doom was ported to the Ikea GU10 lightbulb a couple of
| years ago.
|
| Unfortunately the original post and code all got taken down due
| to copyright claims, but archive has a copy:
|
| https://web.archive.org/web/20210615035229/https://next-hack...
| graphe wrote:
| If you'd like to see this and more in software for flashlights
| please visit toykeeper's projects!
|
| https://github.com/ToyKeeper/anduril
|
| https://toykeeper.net/
|
| I loved this feature on my flashlight and used it exclusively on
| candle mode. There's a lot of thought that goes into it like PWM
| speed or direct drive for LEDs that may or may not cause
| flickering and a tradeoff between battery life and the
| electronics available.
| NikkiA wrote:
| I'd rather they didn't, I recently upgraded our household
| flashlights and was pleased to be able to get 3-mode rather
| than the ridiculous 5 and 7 mode that they were replacing, no
| more having to loop through 'SOS' and several ridiculous flash
| patterns, a half-dozen brightness settings and so on to get to
| the 'full brightness, no flashing' setting that was needed 100%
| of the time.
| danbruc wrote:
| Wait till you have to wait for your candle to boot an off the
| shelf Linux and download security updates before it starts
| flickering.
| queuebert wrote:
| I would have assumed that nowadays using a small neural net to
| approximate a CFD model of a flame would be the easiest.
| dgsgsgegsgsdb wrote:
| Hfjrjrjr
| exmadscientist wrote:
| > Is it possible to improve on this candle-LED implementation? It
| seems so, but this may be for another project.
|
| Hey, I got paid to do this a few years back! Here's the result:
| https://evietealight.com/
|
| They're the sort of thing it's not really possible to show off in
| a photo or even video. What really gets you (or at least gets me)
| is seeing these things out of the corner of your eye, flickering,
| just like flames flicker....
|
| This was a pretty uncertain research project. We didn't know if
| we'd be able to make really convincing flameless flames. The day
| I knew we'd got it was the day I brought a prototype home to tune
| and A/B test against a real candle. I went upstairs to put the
| kid to bed, then came downstairs and panicked because I thought
| I'd left the real candle burning. I hadn't! I got fooled by my
| own product. It was all downhill from there.
|
| These guys are patented (somehow... the language is pretty
| impenetrable, and it's my own patent...) so I don't mind sharing
| a little of how it's done: there's an array of LEDs plus
| optically-active element, which shapes the light in a way that
| makes it look good. Nothing about this is too complicated (the
| optical surfaces aren't all that special, but are not trivial to
| prototype in your garage, at least if you've never done optics
| before), but there was a lot of R&D to settle in on what looks
| "right", and the final product has a lot of "premium" touches
| that really drove up the manufacturing cost. Hence the high final
| cost -- they really do cost a lot to make.
|
| But they look awesome!
|
| (And thanks Tim for your original article -- I definitely
| remember reading it during the early research phase!)
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