[HN Gopher] The Analog Thing: an open source, educational, low-c...
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The Analog Thing: an open source, educational, low-cost modern
analog computer
Author : uticus
Score : 200 points
Date : 2023-06-02 14:25 UTC (8 hours ago)
(HTM) web link (the-analog-thing.org)
(TXT) w3m dump (the-analog-thing.org)
| ardoise wrote:
| The value of analogue computation is limited. They are not
| universal computers. The problem with analogue computers is that
| there's a limit on the number of consecutive operations that they
| can perform to produce a useful result. With digital computers,
| errors can be corrected after each operation. Whereas with an
| analogue computer, evey step introduces noise which cannot be
| corrected. It cannot be corrected because in an analogue system
| any input value is 'valid'. In a digital system input values that
| are slightly higher or slightly lower than a digit can be
| corrected to the nearest digit.
| oersted wrote:
| While it's true that analog computers have limitations in terms
| of precision and error correction compared to digital
| computers, they can still offer some advantages in certain
| applications. For example, analog computers can be faster and
| more energy-efficient for specific tasks, such as solving
| differential equations or simulating physical systems.
| pfdietz wrote:
| Also, making analog computer components requires high
| precision. With digital components, the individual elements are
| driven to saturation, so much less precision is needed. This
| means digital components can be made very small. Indeed, this
| is why integrated circuits work so well.
| tacotacotaco wrote:
| This recent article talks about advantages of analog computers
| and their possible uses as coprocessors to digital processors
|
| https://www.wired.com/story/unbelievable-zombie-comeback-ana...
| tamaharbor wrote:
| I knew digital was just a fad.
| shagie wrote:
| https://mythic.ai is an analog chip for doing neural nets.
|
| https://youtu.be/GVsUOuSjvcg?t=898 (this is a time stamp'ed
| link for a video mentioned elsewhere in the comments).
| depingus wrote:
| Saw this a while ago. I don't know enough about math to know
| if this works as described...I hope it does! A tiny dedicated
| chip for AI inference jobs is probably the next game changer
| the industry needs to put AI in everyone's pocket. Too bad
| OpenAI is going to kill any chance at something like this
| with regulatory capture.
| mrguyorama wrote:
| If you have an iPhone or a modern Pixel, you already have a
| dedicated AI accelerator in your pocket.
| depingus wrote:
| Actually, I have a Pixel 7 with the Tensor G2. I can't
| find the tera operations per second on it, but Google has
| said that its [1] 60% more powerful than their Tensor
| Coral (4 TOPS at 2W of power). That puts the G2 at about
| 6.4 TOPS.
|
| The Mythic analog chip [2] is pumping 25 TOPS at 3W. For
| comparison, modern (digital) GPUs are doing 25-100 TOPS
| at 50W-100W...while costing >$1000. So, its a big jump.
|
| [1] https://www.xda-developers.com/google-
| tensor-g2-changes/
|
| [2] https://youtu.be/GVsUOuSjvcg?t=1060
| deutschepost wrote:
| Very cool! Albeit I don't see the educational value if not paired
| with an oscilloscope and/or loudspeaker.
|
| This screams modular system at me. And I think it is much easier
| to learn what all of these functions do when combining multiple
| senses.
| penguin_booze wrote:
| Related: Versatium's video on analogue computing:
| https://youtu.be/GVsUOuSjvcg.
| jamesgill wrote:
| I love the idea as a learning tool, but:
|
| 1. ~USD $535 isn't exactly 'low-cost'
|
| 2. I'm confused who the audience is.
|
| It can't be kids--this is too advanced. It can't be engineers (or
| student engineers)--there are better, more practical learning
| tools. Maybe people with an extra $500 who just enjoy fiddling
| around?
| armitron wrote:
| Nerds with too much disposable income who will buy this, spend
| maybe 20 minutes total and then put it away to collect dust.
| hobo_in_library wrote:
| My raspberry pi is looking at your post guiltily
| mikepurvis wrote:
| To be fair, though, RPi's price point is well within the
| impulse-purchase threshold of normal people, let alone
| wealthy nerds.
| mcv wrote:
| Same here. I fear we may be the target demographic for this
| thing.
| carimura wrote:
| mine too. at least the box (with pi inside) makes a good
| stand for a mesh node.
| kleer001 wrote:
| I could see it being used in classrooms. What level/grade? No
| idea.
| mikepurvis wrote:
| It definitely has classroom energy, but for that to work out
| it would need to come with a whole curriculum, textbook, etc.
| And even then, I think a lot of parents would be asking why
| this oddball thing vs playing with regular 555 and opamp
| circuits on a breadboard.
| squokko wrote:
| LOL! Maybe in Santa Clara
| kleer001 wrote:
| > I think a lot of parents would be asking why this oddball
| thing vs playing with regular 555 and opamp circuits on a
| breadboard.
|
| A lot? Like more than 50% I am very doubtful. But maybe I'm
| running from different demographic intuitions.
|
| I'm not sure how many parents would know the "proper"
| process.
| __MatrixMan__ wrote:
| I just completed "instrumentation lab", a college physics
| class, where we built amplifier circuits (presumably for use
| with sensors in experiments, although we just used a signal
| generator). Seems like this would fit right in since the
| other portion of the class was oscilloscope training.
| mk_stjames wrote:
| A very popular analog computer patchable with 4mm banana jacks
| was the Comdyna GP-6. I went down a rabbit hole of reverse
| engineering it from photos and schematics years ago in order to
| build a version that would fit in a 3U panel for Eurorack modular
| synth interfacing. Never finished it, but the total BOM was...
| well, not much. The panel was going to cost more than the
| board+opamps+passives. I wanted to buy a real Comdyna but I
| remember the cheapest I found one for sale was ~$700 and I
| thought that was expensive. Not so much when you compare it to
| this unit which is housed in just open PCBs and a much smaller
| format.
|
| If you are a student and want to learn a bit more about how
| operational amplifiers, resistors, and capacitors alone can solve
| differential equations... you can get an educational license for
| Matlab for nothing and Simulink can emulate all the analog
| circuitry you want and more.
|
| Another approach might be using the Eurorack simulation software
| VCV Rack - If there isn't an set of modules you can install that
| do basic gain, integrators, multipliers, comparators, etc then it
| would be very easy for someone to write one.
| Archit3ch wrote:
| > If there isn't an set of modules you can install that do
| basic gain, integrators, multipliers, comparators, etc then it
| would be very easy for someone to write one.
|
| VCV Rack cannot do Zero Delay Feedback because each cable adds
| one sample of delay. You can do it inside your module, of
| course.
| thx-2718 wrote:
| Question since you appear familiar with math simulation, could
| you do what you're describing with Matlab with Octave instead?
| ted_dunning wrote:
| Yes.
|
| Easier with Julia, though, because the ODE and PDE support is
| better and you have better / simpler notation. Performance
| will be better as well, but for simple problems you can't
| tell.
| etrautmann wrote:
| Yes, but simulink's graphical interface makes simple circuit
| simulation a bit easier for rapid iteration, testing, etc.
| fsckboy wrote:
| I'm not familiar with matlab or octave :) but I do know the
| discrete and continuous underlying mathematics involved here,
| and from the https://octave.org/ homepage, "the Octave syntax
| is largely compatible with Matlab", the answer is yes.
|
| just to ELI5 for folks, the cool thing about analog computers
| (or digital approximations or simulations) is that since they
| are actually integrating (storing charge in a capacitor as
| the voltage varies) or actually differentiating (current
| through a capacitor varies with the voltage differential/rate
| of change) they can calculate what would be very complex to
| do on paper.
|
| Or more plainly, if the rate that the water flows out of the
| drain of the bathtub depends on the water pressure above
| which depends on the depth of the water in the tub, you can
| study all the math involved (what you did in calculus) or you
| can just put water in the tub and set your stopwatch (analog
| computer); and electrons through or in a capacitor is just
| like water in a tub
|
| this is basically all that's involved inside a music
| synthesizer. The complexity comes from stacking together a
| variety of different concepts once you understand that the
| concepts are stackable (like when they taught you about
| arithmetic being commutative, associative, distributive,
| reflexive, etc)
| pkaye wrote:
| I'm wondering if Modelica might be useful for this. Its an
| open source modeling language though I've never used it. Its
| basically writing models with differential equations for each
| of the components and then connect them together to form a
| system.
|
| https://en.wikipedia.org/wiki/Modelica
| felixgallo wrote:
| https://github.com/countmodula/VCVRackLunettaModula
| ruleforty wrote:
| Might I suggest the LMN-3 - soup to nuts the most positive
| project I see and gaining traction and affordability:
| https://youtu.be/h5UmPTttN1s
| evantbyrne wrote:
| Asking as someone that is not familiar with general purpose
| analog computers: are there benefits over digital?
| JKCalhoun wrote:
| To me the appeal is that they more closely model "the Real
| World". Perhaps like modular synths, they invite
| experimentation, learning (maybe a bit like a graphing
| program?).
| chillbill wrote:
| EUR524,16 EUR is not affordable
| pugworthy wrote:
| Reminds me of the old Science Fair Electronic Computer Kit Model
| No. 28-180 from Radio Shack...
|
| https://www.oldcomputermuseum.com/electronic_computer.html
|
| I had one as a kid and regret a) that I didn't figure it out
| more, and b) threw it away at some point.
| JKCalhoun wrote:
| Those are a lot simpler (no op-amps, mostly resistances and an
| analog meter).
|
| Here are some links to these I have collected:
|
| https://hackaday.io/project/177346-simple-analog-computer-el...
|
| https://computarium.lcd.lu/photos/albums/EDMUND_ANALOG_COMPU...
|
| https://t-lcarchive.org/american-basic-science-club-analog-c...
| aj7 wrote:
| Open source? Really? Where's the schematic?
| lambda wrote:
| Schematics are available https://the-analog-
| thing.org/docs/dirhtml/rst/schematics/ though usually Open
| Source Hardware refers to releasing the original design files,
| including schematic and board layout, rather than just PDFs of
| the schematic: https://www.oshwa.org/definition/
| fkyoureadthedoc wrote:
| If you are looking for documentation, try clicking the
| prominent "read the docs" link. Once you do so, you'll notice
| "THAT schematics" is the very first link after the overview.
| luqtas wrote:
| i wonder why no one commented about Putedata, Csound and
| Supercollider as a cheap alternative...
| gatane wrote:
| A simple analog computer would be a slide rule (or disk). The
| advantage is that it doesn't need batteries, but usually has very
| low precision (about 1.5-2ish decimal digits).
|
| Hell, you can even print it and have a calculator with
| mul,div,sin,log,[?]...
| samtho wrote:
| I've been toying with the idea of building a "learn analog
| electronics" course by having the student build a musical
| synthesizer one stage at a time, starting with dual tone
| generators that can be made to deliver frequencies and a
| selectable wave pattern, then through to evelope filters,
| modulator (which part of it exists as the wave selection from
| earlier), and all the controls to make it happen. Not sure if
| this has been done or if it's a dumb idea.
| pkaye wrote:
| Have you checked out Lantertronics on YouTube? He has a course
| "Analog Circuits for Music Synthesis" but it might be tough for
| beginners to follow.
|
| https://www.youtube.com/@Lantertronics/videos
| TylerE wrote:
| The trickest part I see there is you're going to need some sort
| of midi input and associated parsing to actually make the thing
| playable.
|
| Or are you thinking of building a keyboard as well.
|
| I suppose there are probably MIDI to CV modules out there one
| could source.
| samtho wrote:
| I was going to have them build a rudimentary octave (12 note
| keyboard segment) but that has been something I've been
| trying to sketch out as well.
| TylerE wrote:
| A theremin input maybe? Could even be part of the build
| experience. No mechanical parts, which is nice, and pitch
| bends are fun sounds.
| cmpalmer52 wrote:
| It sounds like a great idea to me. I've been trying to carve
| out time to do more electronic tinkering and learning and that
| sounds like a neat set of projects.
| mikelovenotwar wrote:
| Erica Synths and Moritz Klein have released an educational
| eurorack synth range of modules with many resources for
| learning:
|
| https://www.youtube.com/@MoritzKlein0
|
| https://www.ericasynths.lv/shop/diy-kits-1/mki-x-esedu-diy-s...
| Animats wrote:
| That's cute. Almost exactly the same capabilities as the tube-era
| Heathkit EC-1 educational analog computer [1], but much smaller.
|
| Analog computers are no fun without an oscilloscope. Once you can
| see graphs, you get intuition about how the inputs affect the
| outputs. If you only have a meter, you have to write down data
| and plot.
|
| [1]
| https://www.analogmuseum.org/library/heathkit_ec1_operation_...
| JKCalhoun wrote:
| Yeah, wish it at least had an analog meter.
| Animats wrote:
| They should have built in one of these $20 oscilloscopes[1]
| in place of the LCD meter. And a speaker. Their Analog Thing
| costs over US$500, after all. Then you'd have a self-
| contained unit good for student use.
|
| [1] https://www.aliexpress.us/item/3256805426720735.html
| pwenzel wrote:
| According to section 6.1 of the manual, it can be connected to
| an oscilloscope.
|
| https://the-analog-thing.org/THAT_First_Steps.pdf
| BSEdlMMldESB wrote:
| but what is the 'software' equivalent for this thing?
|
| the physical state of all them wires? not very portable
| jcpst wrote:
| Think of it in a streaming/functional way. Programming would be
| about signal flow, components that transform, and you get a
| continuous output.
| jsiva wrote:
| You can model passive circuits with RLC ordinary differential
| equations (depending on the setup of the equations there's some
| algorithms such as Runge Kutta to solve them numerically).
| Afaik you can model some active components with ordinary
| differential equations, but I wouldn't be surprised if you had
| to resort to partial differential equations (More or less a
| "complete" electromagnetic simulation at that point).
| BSEdlMMldESB wrote:
| you're onto something
|
| I was looking at some of the open documentation[1] and they
| show schematics and differential equations alongside each
| other.
|
| I just keep burning out whenever I try to make sense of these
| things;
|
| [1] https://the-analog-thing.org/THAT_First_Steps.pdf
| ulv wrote:
| polaroids
| mxdgkat wrote:
| [flagged]
| fit2rule wrote:
| [dead]
| 7thaccount wrote:
| Very cool, but it would need to be closer to $200 for me to openu
| wallet.
| dang wrote:
| Related:
|
| _The Analog Thing: An open source, educational, low-cost modern
| analog computer_ - https://news.ycombinator.com/item?id=28614840
| - Sept 2021 (65 comments)
| spyremeown wrote:
| Is 499 EUR for that BOM fair? Genuinely asking... high end SoM
| modules with carrier boards and a metric ton of software can be
| obtained by half of that price, and op-amps aren't that costly.
| pfdietz wrote:
| Mechanical analog computers used in WW2 era warships were quite
| interesting.
|
| https://arstechnica.com/information-technology/2020/05/gears...
| 908087 wrote:
| [dead]
| spend_thrift wrote:
| I just want to know when someone is going to get around to make a
| single board photonic computer...
| mcdonje wrote:
| That's really neat. Veritasium did a couple of videos on analog
| computing a year ago. I'm glad there are people lowering the
| barrier to entry.
|
| https://youtu.be/IgF3OX8nT0w
|
| https://youtu.be/GVsUOuSjvcg
| pradn wrote:
| These are fantastic, thank you for sharing!
| gigel82 wrote:
| Neat, but... this "analog" thing's built with a lot of digital
| circuitry
| bgribble wrote:
| Very familiar-looking to anyone who has been following the
| modular synthesizer renaissance. Modular synths are basically
| analog computers, just not well-optimized for precision in most
| cases. All the basic building blocks of THAT are available as
| modules from a number of boutique manufacturers.
| DennisP wrote:
| And "not well-optimized for precision" is often considered a
| feature.
| gatane wrote:
| It was so cool to realize that NIN used one for making a song.
| Caustic had an emulated one with a lot of features, but I dont
| know if there are other DAWs with similar ones...
| z5h wrote:
| I was looking for the modular synth comment(s). That's
| immediately what came to mind when I saw this. How can I
| integrate this with my synths.
| jcpst wrote:
| Yeah- as a long time modular synth user I practically drool
| over stuff like this. But for the money I can just get more
| synth modules.
| ftxbro wrote:
| i would buy one if it cost ten dollars not five hundred dollars
| so-and-so wrote:
| Very interesting device. But it costs as much as an office PC,
| that can emulate this analog computer and do a lot more.
| qubex wrote:
| A digital computer cannot emulate an analog computer: it can
| only simulate it to an arbitrary level of precision. That's the
| whole point.
| dmos62 wrote:
| The difference between the words emulate and simulate are
| difficult to grasp for me. One comes from the latin `aemulus`
| and the other from `similis`. One talks about imitation and
| the other about similarity. When people discuss the
| differences between these terms, they say things like one
| aims to be able to replace a thing, while the other aims to
| replicate the thing's internal state. Or, that one aims to
| replicate the external behaviour, and the other aims to
| replicate the internal state.
|
| I somewhat discard these interpretations. My conclusion, is
| that emulation is about making something equal to something
| else under some circumstance, while simulation is about
| approaching emulation (under some circumstance), but not
| aiming or achieving complete emulation (under that
| circumstance). Basically, the difference between becoming
| equal and becoming similar. This is counter to popular usage
| I think, but popular usage is a bit of a mess, in my opinion.
| qubex wrote:
| The concept of perfectly accurate emulation lies at the
| core of formal definitions of computing such as Turing's
| seminal "Turing Machine" introduced in "On Computable
| Numbers" way back in 1936.
| amelius wrote:
| The problem with simulation is that it might produce
| artifacts that a user might exploit ("hey, this is cool!")
| and then finds out that it only exists in the simulation,
| not in the real world.
| samstave wrote:
| What was that application from a long time ago that had
| analog wiring sound systems that you had to manually (on
| screen) connect a wire between ports... and you could flip
| the rack from front to back?
|
| --
|
| One of my best friends growing up built a ton of analog
| mixers IRL while working at Melekko Heavy Industries... (I
| helped him a tiny bit create the CAD files for the CNC for
| the faceplates.)
| gpas wrote:
| Reason?
| samstave wrote:
| Yep!
|
| Thats the one - imagine if you had an UX/UI to
| mynoise.net with a REASON frontend?
|
| We should escalate this as a "bug which is missing as a
| _feature_ " that they dont have a UX like this :-)
|
| Stephane @ mynoise.net
| mjhay wrote:
| Analog computers don't have infinite precision due to the
| presence of noise, so digital computers can emulate that with
| high-enough precision arithmetic.
| qubex wrote:
| 'Emulation' means something very specific. What you are
| speaking of is "simulation to an arbitrary degree of
| precision", as I mentioned.
| bheadmaster wrote:
| > 'Emulation' means something very specific
|
| What exactly? And how does it differ from "simulation"?
| qubex wrote:
| Simulation is about mimicking another device or system.
| Emulation is about setting up a system that is logically
| indistinguishable from another irrespective of its
| implementation substrate and details thereof.
|
| A thing is successfully 'emulated' when it is logically
| impossible to distinguish the difference between the
| system and its emulated counterpart.
| SamBam wrote:
| Since, as you said in a sister reply, even one analog
| computer might be slightly different from another analog
| computer, and thus unable to emulate it, if you had the
| outputs of two different computers, one analog and one
| digital one simulating it to a high precision (higher
| than the noise of the analog one) how could you
| distinguish which was digital and which was analog?
|
| If you can't, then this is a meaningless semantic
| discussion. The digital computer can emulate the analog
| one as well as any other analog computer can.
| qubex wrote:
| The point is that discrete computers can exactly and
| trivially emulate each other. The inability to emulate an
| analog computer by a digital or analog computer kind of
| is the whole point.
| flir wrote:
| You know, by that definition one analogue computer can't
| emulate another of the same model.
| qubex wrote:
| Exactly! For analog computers, every single 'run' is
| different!
| shultays wrote:
| Sure you can, you only need to simulate it to near some
| orders around the planck constant. And then you can go even
| further. Analog does not have infinite precision either
| qubex wrote:
| As a concept, analog computers rely upon an assumption of
| continuity.
| shultays wrote:
| But due to limitations of physics, nothing will be
| continuous.
|
| Is amount of water in a bucket continuous? No, you can
| count each individual atoms. So you can simulate that by
| using large enough integers. Same principle applies
| everwhere
| qubex wrote:
| These are assumptions. If you think the assumption of
| continuity is ridiculous, note that the definition of
| universal Turing machines requires an infinitely long
| tape (infinite memory), which of course conflicts with
| the finite memory of any actually implementable digital
| computer.
| shultays wrote:
| I am not saying you need a turing machine, a finite one
| will do since we are also dealing with a finite analog
| system. If analog system is finite and has finite states
| that we can measure, then a finite computer will just do
| fine
| qubex wrote:
| I'm saying that these properties are derived from equally
| ultimately unrealistic scenarios.
|
| I'm honestly quite surprised that people are chiming in
| with their 'opinions' on proven mathematical facts.
| deelowe wrote:
| > A digital computer cannot emulate an analog computer:
| it can only simulate it to an arbitrary level of
| precision. That's the whole point.
|
| A modern digital computer can simulate this particular
| analog computer beyond the noise floor. Practically
| speaking, that means a digital computer can perfectly
| emulate this system therefore it's simply a toy or
| perhaps for aesthetics.
| mjhay wrote:
| That's much less cool though.
| orbital-decay wrote:
| It's an educational board. I made a custom educational board
| for my kid a few years back (with a 16 bit digital CPU though)
| just to have something physical, with the possibility to be
| underclocked to extreme values and a bunch of LEDs in key
| points to illustrate the principle. I could have used an
| emulator, but something like that is 1000x better as it's bare
| metal and doesn't have any black magic under the hood.
| shagie wrote:
| When it was originally released it was a bit less expensive
| than the current price on it (glad I got one then).
|
| https://web.archive.org/web/20220528131517/https://shop.anab...
| RobotToaster wrote:
| Is it actually open source? I can only find PDF schematics, not
| source files. The git link takes me to a closed gitlab instance.
| TheRealPomax wrote:
| But if folks could also maybe come up with a way to make patch
| cables not destroy any sense of understandability, that'd be
| great.
|
| (and maybe solve the whole "good luck 'saving' the thing you just
| made" problem at the same time, too. cheers)
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