[HN Gopher] Show HN: I built a JavaScript-powered flipdisc display
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Show HN: I built a JavaScript-powered flipdisc display
Author : simpsoka
Score : 255 points
Date : 2024-06-25 15:14 UTC (7 hours ago)
(HTM) web link (flipdisc.io)
(TXT) w3m dump (flipdisc.io)
| imzadi wrote:
| How do they have no moving parts?
| omneity wrote:
| One could argue flipping doesn't change X, Y nor Z coordinates
| :)
| adolph wrote:
| Seems koan-ish: What is the movement of a
| stone standing still? What is the rolling rock
| that goes nowhere?
| dylan604 wrote:
| that's my question too. if there's not moving parts, how does
| the disc flip if it doesn't move. if there's nothing moving,
| what is all of that noise.
| simpsoka wrote:
| The disc moves, but there aren't any moving mechanical parts to
| cause it to move. It's done with electromagnetic pulses. I'll
| update it to make this more clear.
| crazygringo wrote:
| I don't really see what the distinction is?
|
| You might as well say a motor has no moving parts, because
| it's done with electromagnetic impulses. But that would be
| absurd.
|
| Obviously the hinge of each disc will wear and tear and
| eventually fail. Buildups of dust and oil will affect them
| too and prevent them from flipping. Flipdiscs are as
| mechanical as mechanical parts get.
|
| You writing in the intro: "...have no moving parts, near
| limitless lifespan..." is just not credible.
|
| And if I'm being entirely honest, that's where I stopped
| reading your post, because you simply didn't seem
| trustworthy. You might want to focus more an accuracy rather
| than hyperbole if you want to maintain readers.
| beatboxrevival wrote:
| Probably because they are just a hobbyist and not an expert
| in the field (nor do they assert that they are). Maybe be a
| little kinder on the internet. It sounds like it was just a
| minor oversight.
| crazygringo wrote:
| > _Maybe be a little kinder on the internet._
|
| I really did think about whether or not to write that
| last paragraph. But the thing is, it's the truth. And I
| think it's going to be more helpful in the long run for
| authors to know these things.
|
| Believe me, I've been on the receiving end many times and
| it's made me a vastly better writer and communicator.
| When somebody stops reading your article because of a
| howler, it's much better for you to hear why so you can
| learn from it.
|
| (And you don't need to be an expert in the field to
| realize that discs that flip are mechanical, or that they
| don't have a "near limitless lifespan". These aren't
| exactly subtle mistakes, and it's one of the main
| justifications presented in the introduction itself.)
| simpsoka wrote:
| Thanks for the feedback. I've updated the article.
| risenshinetech wrote:
| You're seriously insinuating that a person has to be an
| expert in the field to be able to identify that a device
| with moving parts has... moving parts in it?
| lucianbr wrote:
| The entire history of the world stands as proof that
| focusing on hyperbole maintains readers better :)
|
| Though I do wish for more accuracy. These things are
| totally moving parts, and there is no way they have even a
| long lifespan, let alone a "near limitless" one. Though to
| be precise, "near limitless" is meaningless.
| risenshinetech wrote:
| It's amazing the type of pretty tame criticism that gets
| downvoted here these days. Your criticism is entirely
| factual and has zero hint of malice. I felt the exact same
| way when I read these things in the article -- just pure
| nonsense.
| simpsoka wrote:
| So sorry to have caused the confusion. I've updated the
| post to be more detailed. Honest mistake. I was
| referencing the mechanical parts of the board that move
| the dot. For example, unlike Vestaboards, which have a
| gear to move the panels, flipdisc boards use magnets.
| Good thing pixels on a webpage are easier to update than
| pixels on a flipdisc board!
| endisneigh wrote:
| Probably best to say mechanical movement.
| simpsoka wrote:
| Updated to make this more clear! Sorry for the confusion.
| beatboxrevival wrote:
| I've been coveting a Vestaboard, but this seems like a more
| interesting alternative. Thanks for the guide!
| seanvelasco wrote:
| reminds me of a certain art installation at Changi Airport in
| Singapore. it was the first cool thing I saw in that country
| pvg wrote:
| The beginning of the demo video is reminiscent of Ye Olde Wooden
| Mirror
|
| https://www.smoothware.com/danny/woodenmirror.html
|
| or more recently
|
| https://tisch.nyu.edu/itp/news/spring-2024/daniel-rozin--itp...
| simpsoka wrote:
| That's rad! I didn't know about Wooden Mirror
| tailspin2019 wrote:
| That's awesome. Looks like the wooden pixels rotate to reflect
| more or less light to achieve various shades of "grey".
|
| Ingenious!
| LordShredda wrote:
| I think the javascript here plays a rather small part in the
| entire assembly.
| nico wrote:
| This looks amazingly cool. Love the old school "analog" feel of
| it
|
| Thank you for sharing
| nayuki wrote:
| Well, it's mechanical but still digital. Each pixel is either
| on or off. Locations are discrete and finite.
| notatoad wrote:
| i'm sure i'm not the only one who wanted this information:
|
| >AlfaZeta makes brand new displays, with a controller board.
| Their XY5 displays (14x28) sells around 500EUR (VAT and shipping
| included).
|
| https://hackaday.io/project/159415-flip-dot-display-diy-cont...
| carb wrote:
| I was about to post the same.
|
| The result is really nice, and makes the conclusion make a lot
| of sense.
|
| > I do hope that flipdiscs become more accessible for
| hobbyists. If anyone wants to collaborate on new affordable
| flipdisc hardware, let me know!
|
| EUR4500 is quite the pill to swallow (unless prices have gotten
| cheaper since that 2018 Hackaday project)
| simpsoka wrote:
| I paid a fraction of that. They'll come up on eBay every once
| in a while.
| carb wrote:
| great to hear!
| anfractuosity wrote:
| You could also have a look for used bus signs on ebay, or I
| imagine scrap yards might have them too. I got a 14x20 display
| for around PS50.
| BeefySwain wrote:
| How exactly did the author get the panels? I've looked into stuff
| like this before and it's basically impossible to source outside
| of things like eBay. Unless you're willing to buy industrial
| quantities at industrial prices.
|
| How did they buy them, and for how much?
| simpsoka wrote:
| I got mine off eBay, but you can get the same panels from
| AlfaZeta. There are some more affordable options like:
| https://xqd-
| led.en.alibaba.com/productgrouplist-936470954-2/.... I do
| mention in my post that I would like to see these panels become
| more affordable for hobbyists. If anyone wants to collaborate
| on this, please contact me!
| fragmede wrote:
| What's wrong with eBay?
| simpsoka wrote:
| Nothing - just might have to wait a bit for them to come up.
| lanewinfield wrote:
| Speaking as someone who also recently purchased these panels
| (and read the second paragraph where they mention where they
| got them), they're from the company AlfaZeta.
|
| They build and ship from Poland. They don't have a publicly
| available price list but they cost approx 220 EUR per 7x28
| panel. Expensive, but few places still manufacture them.
|
| If you continue reading the post, they also link out to other
| manufacturers including ones on AliExpress that seem to be
| cheaper.
| jstanley wrote:
| What is up with the URL?
| qmarchi wrote:
| Excellent question, it should probably be changed to
| https://flipdisc.io/ (truncating everything after the first /)
| simpsoka wrote:
| Sorry, I don't know how that got added. It's
| https://flipdisc.io/
| pvg wrote:
| It's this misline in your html
|
| <link rel="canonical" href="http://localhost:4321/">
|
| HN extracts these.
| simpsoka wrote:
| Cool, thanks! I'll update that.
| dang wrote:
| And handles them inappropriately, it seems, since we
| converted the URL to
| https://flipdisc.io/http://localhost:4321/.
|
| I've fixed it now.
| proee wrote:
| Breakfast studio offers some amazing art pieces using Flipdisc
| modules.
|
| https://breakfaststudio.com/flip-discs
| ianbicking wrote:
| Having silver on one side and an abstract/neutral design on the
| other side is an excellent effect
| beatboxrevival wrote:
| Looks like you can get custom colors here too: https://xqd-
| led.en.alibaba.com/productgrouplist-936470954-2/.... And
| likely much more affordable than Breakfast.
| amelius wrote:
| They have a work that shows melting polar ice, but I wonder how
| energy efficient it is (I expect it does not consume energy
| when nothing flips, but still ...)
| ape4 wrote:
| Whats the expected lifetime for a flipdisc display like that
| simpsoka wrote:
| over 150 million operations on average -- from alfazeta
| documentation
| its_ethan wrote:
| I was curious roughly how long 150 million operations is...
|
| Assuming (literally just a guess) that the tiles "operate" at
| a rate of 3 times per second playing back a video or
| something:
|
| (150 million operation) / (3 operations/ second) = 50 million
| seconds = 578 days
|
| It's likely much slower than 3 operations per second too - so
| probably 6-10x that in reality, which would be on the order
| of a decade of continuous runtime before they reach expected
| EOL.
| rhaps0dy wrote:
| > Flip displays are an interesting alternative. They have no
| moving parts,
|
| What? The display is made almost entirely of moving discs.
| simpsoka wrote:
| See discussion below. I just need to update the copy.
| lucianbr wrote:
| Except for the moving parts, there are no moving parts. What's
| unclear? :)
| nayuki wrote:
| Where is the obligatory Touhou Bad Apple animation on this black-
| and-white display?
| sphars wrote:
| This is what I was hoping to see, seems like the logical next
| step in showing off this awesome project!
|
| For the unawares, the original video:
| https://www.youtube.com/watch?v=FtutLA63Cp8
|
| My favorite version, also using real-life objects:
| https://www.youtube.com/watch?v=lT-fdnIK0k0 (HN discussion:
| https://news.ycombinator.com/item?id=39527559)
| leetharris wrote:
| This is so cool.
|
| I love to see Javascript used for stuff like this. It blew my
| mind that the James Webb Telescope uses a custom Javascript
| runtime for a lot of the onboard functions.
| spankalee wrote:
| The SpaceX Dragon capsule touchscreens run an HTML/JS app built
| using web components (Polymer) :D
| bigstrat2003 wrote:
| That's horrifying. Javascript doesn't belong anywhere near
| anything which isn't a web page, and even then it's
| questionable.
| phist_mcgee wrote:
| Maybe the engineers at NASA know what they're doing?
| risenshinetech wrote:
| Why do you love to see a particular language used for
| something?
|
| It would be like being excited at seeing someone using aluminum
| to build something over steel/wood/etc.
| aembleton wrote:
| Not the parent, but I like seeing particular languages used
| for something like this because it may be a langauge that I
| am familiar with along with all of its libraries and tooling.
| This makes a project like this that interacts with hardware
| easier to acheive.
| pengaru wrote:
| tribes
| scosman wrote:
| Love this.
|
| Reminds me of the "flip flap" boards in old train stations. Like
| https://www.vestaboard.com/
| yojo wrote:
| Man I love those things. I have warm memories of standing in
| Italian train stations as a kid and letting the clacking wash
| over me when they did a full board refresh. It'd fade out like
| a rain stick as the stragglers that started furthest from their
| target letter trickled in.
|
| Now it's all LED, which is way more practical and so much less
| magical.
| wrs wrote:
| I wish they would just fake the sound effect (hey, electric
| cars do it).
| omoikane wrote:
| > near limitless lifespan
|
| The lifespan is probably not as limitless as you might have
| imagined, the discs tend to fall off or get stuck. But they are
| really neat while they are working, especially how they sounds.
|
| I was at an office with these flip dot displays, and eventually
| we dismantled the display. I took some picture of the pieces and
| you can see how stuck discs look like:
|
| https://photos.app.goo.gl/onpHefUVL8oeP4si7
| simpsoka wrote:
| For sure. They're similar to butterfly wings. It's easy to lose
| or break discs. Our kids loved touching them while we were
| building, and we'd constantly have to replace discs that fell
| off.
| amelius wrote:
| > The lifespan is probably not as limitless as you might have
| imagined
|
| How do you remove dust from them? I imagine that's when they
| break.
| wrs wrote:
| The linked Alfazeta manual has recommendations for very
| carefully vacuuming the panel.
| tivert wrote:
| > We used 9 Alfazeta panels in a 3x3 grid or 84x42 discs. Each
| board has (2) 28x7 panels.
|
| So how much do one of those cost? The website
| (https://flipdots.com/en/products-services/flip-dot-boards-xy...)
| notably has no prices listed.
| elaus wrote:
| This [1] page talks about 500 EUR per display which would
| result in about 3000 EUR for a 3x3 grid or 1.27 EUR per pixel.
|
| I love the idea but that's WAY to expensive for me.
|
| [1] https://hackaday.io/project/159415-flip-dot-display-diy-
| cont...
| lanewinfield wrote:
| Each board is, as of this year, 220 EUR per 7x28 panel. Still
| expensive! But specialized.
| wferrell wrote:
| Kath - so cool to see this is you! What a great project. Well
| done.
| simpsoka wrote:
| Hey hey! Thank you!!
| dehugger wrote:
| This is incredibly cool! Does the video audio amplify the sound
| of the discs flipping or are they really that loud?
| simpsoka wrote:
| They can be a little loud, but I find it pretty soothing, tbh.
| It's sort of like a rain storm.
| yyyfb wrote:
| I built a lo-fi device like this (with a LED matrix instead of a
| flipboard) and I didn't really find great software for building
| animations at a low pixel count. I ended up doing something super
| low level where I draw to a buffer directly using ImageMagick. If
| there's a better library I'd love to know.
| wrs wrote:
| The stack here is lo-res but not lo-power. "...we're leveraging
| existing web tech that we've found to work well - PIXI for
| general 2D rendering, Three.js for 3D rendering, Matter.js for
| physics engine, and GSAP for animations. We also utilize node-
| canvas, and node-gl for server-side rendering."
| tailspin2019 wrote:
| In a world of flat featureless screens, I _really_ love the
| physicality of this. Even the noise it makes. It feels like it
| communicates a lot more than its raw "pixel" count would suggest.
| simpsoka wrote:
| I love this and agree. I think having art that bridges the
| digital/physical divide will only be more important in the
| world of AI.
| Corrado wrote:
| I think this could be useful as a NOC monitor. Mostly the display
| is static but if something goes wrong the display updates and the
| noise naturally draws your attention. No "alarm" necessary.
| simpsoka wrote:
| I love this idea. It alerts you without the adrenaline spike.
| eterevsky wrote:
| I was expecting Bad Apple on flipdiscs.
| cperry wrote:
| Amazing work, I've long dreamed of building some sort of magical
| chyron or ticker using flip discs.
| simpsoka wrote:
| Thanks!! With scenes you could add a ticker for something to
| this board.
| nayuki wrote:
| Fun fact: Texas Instruments DLP (Digital Light Processing) are
| like a miniaturized version of the flip-disc display.
|
| But some differences are that flip-discs rotate 180deg whereas
| DLP pixels only tilt a little bit to redirect the light to a
| heatsink, flip-discs have different colors on each side whereas
| DLP has mirror pixels, flip-discs probably have finite lifespan
| whereas DLP is good for trillions of cycles, and DLP responds so
| quickly (in microseconds) that grayscale is accomplished by duty
| cycle modulation (PWM).
| hex4def6 wrote:
| It would be really cool if you could read out the state of the
| grid as well. You could then use the display as SRAM. Would look
| very cool as part of the world's slowest microcontroller.
| IIAOPSW wrote:
| As for what to do next, there is nothing I want more than the old
| split-flap departure board of Penn Station. It was exactly like
| this one https://www.youtube.com/watch?v=U8azGTsslNc
|
| The clicking, its sooooo satisfying.
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