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simpsoka
Show HN: I built a JavaScript-powered flipdisc display flipdisc.io

omoikane3 months ago

> 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

simpsokaop3 months ago

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.

amelius3 months ago

> 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.

wrs3 months ago

The linked Alfazeta manual has recommendations for very carefully vacuuming the panel.

vasco3 months ago

Wouldn't you just make the picture change a few times to remove dust and that's it? They flip, the dust comes out.

garfieldnate3 months ago

Doesn't dust usually cling to surfaces due to static electricity and, in some settings, presence of grease in the dust?

kajecounterhack3 months ago

You can individually remove the discs and use a compressed air cannister, but it's very laborious.

nayuki3 months ago

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 180° 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).

proee3 months ago

Breakfast studio offers some amazing art pieces using Flipdisc modules.

https://breakfaststudio.com/flip-discs

amelius3 months ago

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 ...)

ianbicking3 months ago

Having silver on one side and an abstract/neutral design on the other side is an excellent effect

beatboxrevival3 months ago

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.

dtagames3 months ago

Amazing art from this studio! If you like this stuff, check out their "brixels" pieces like the one titled Ocean for the new Fontainebleu Hotel in Vegas

BeefySwain3 months ago

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?

simpsokaop3 months ago

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!

sbarre3 months ago

Do you mind sharing how much the panels cost from eBay?

I feel like that's a key data point that would help people decide if they want to explore this further.

edit: someone further down the thread discusses pricing: https://news.ycombinator.com/item?id=40791049

lanewinfield3 months ago

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.

fragmede3 months ago

What's wrong with eBay?

simpsokaop3 months ago

Nothing - just might have to wait a bit for them to come up.

leetharris3 months ago

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.

spankalee3 months ago

The SpaceX Dragon capsule touchscreens run an HTML/JS app built using web components (Polymer) :D

ClassyJacket3 months ago

That's mind blowing, so I looked it up.

https://news.ycombinator.com/item?id=19739454

Still not sure why they chose JavaScript.

According to their paper it's a commercial JavaScript engine however:

https://ui.adsabs.harvard.edu/abs/2006SPIE.6274E..0AB/abstra...

risenshinetech3 months ago

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.

aembleton3 months ago

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.

beaugunderson3 months ago

to speak to your example: my girlfriend's dad was a welder on aluminum boats. he is always excited to see aluminum boats, find out who built them, etc.

bl4ckneon3 months ago

It's also intresting to see a language used in a way it's not intended to necessarily our for a creative/unique use. Why do people like to port doom to random devices, because it was never indended to run on those (and it's a challenge/meme at this point)

leetharris3 months ago

Sorry, late reply, but I think it's still worth answering.

I think Javascript is a really fun language. I've done a lot of embedded C and it can be... exhausting? I would love to try Javascript on an embedded system, IoT device, etc. I'll bet a lot of the most annoying stuff can be abstracted away pretty easily on modern hardware.

pengaru3 months ago

tribes

sbarre3 months ago

What a cynical take, especially here in a community that should be celebrating novel uses of technology, whether it would be your choice or not.

verbalstoner3 months ago

There is nothing new about using JS for UI, as that is the only place it belongs.

bigstrat20033 months ago

That's horrifying. Javascript doesn't belong anywhere near anything which isn't a web page, and even then it's questionable.

phist_mcgee3 months ago

Maybe the engineers at NASA know what they're doing?

ClassyJacket3 months ago

As a JavaScript hater, I admit they surely they do, but I'm still curious as to why it was the best choice. If it's a custom runtime, existing runtimes being reliable\secure\well understood by existing engineers isn't relevant. And it's not like they're adding in lots of external libraries either.

I found this comment: https://news.ycombinator.com/item?id=19739454

" The language itself wasn’t so important as having adequate performance, robustness, memory use, reproducibility and extreme QC"

but I still don't understand. Interesting they went with a language that doesn't even have integers.

At least the comments on this reddit thread have some hilarious jokes:

https://old.reddit.com/r/javascript/comments/wrtny3/the_jame...

Looks like they released a paper, the abstract of which, indicates it's not a fully custom runtime, which would make more sense:

https://ui.adsabs.harvard.edu/abs/2006SPIE.6274E..0AB/abstra...

Unfortunately they want money to read the rest of it and I'm curious but not that curious, and I probably wouldn't understand it anyway.

phist_mcgee3 months ago

It's a very readable paper. The paper's DOI is 10.1117/12.671403, and you can read it for free on Sci Hub.

ClassyJacket3 months ago

Thanks. Yeah, I thought of that, but I'm at work at a place where I very much should not be having Sci Hub in my browsing log.

tetris113 months ago

no one's doubting it, but they still want to know the reason because it goes contrary to the expectations of most developers here, even the JavaScript fans

Corrado3 months ago

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.

simpsokaop3 months ago

I love this idea. It alerts you without the adrenaline spike.

newaccount743 months ago

Pretty sure your brain will quickly associate the gentle sound of the display switching with the dreadful feeling that something went wrong...

nayuki3 months ago

Where is the obligatory Touhou Bad Apple animation on this black-and-white display?

sphars3 months ago

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)

tuna-f1sh3 months ago

Nice. I also have a fondness for flip-dots. Started with Javascript controller for Hanover bus display (https://engineer.john-whittington.co.uk/2017/11/adventures-f...) and continued with the Alfa-Zeta modules following a commission to make the controller for a 256x56 one - 24 panels!

For that I used a Python module (https://github.com/tuna-f1sh/flipdot) and Python Flask/React based manager, with sequence info in a SQLlite db. Same outcome as your App with pre-loaded transitions and of course, Game of Life: https://engineer.john-whittington.co.uk/2020/04/game-of-life...

It's my project TODO list to make a FPGA based direct HDMI controller for the Alfa-Zeta modules since refresh rate of the on-board firmware leaves a little to be desired.

pvg3 months ago

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...

simpsokaop3 months ago

That's rad! I didn't know about Wooden Mirror

tailspin20193 months ago

That’s awesome. Looks like the wooden pixels rotate to reflect more or less light to achieve various shades of “grey”.

Ingenious!

[deleted]3 months agocollapsed

rob743 months ago

> flipdisc displays are sort of an obscure technology

"niche technology" is probably the better term - that niche being readability in sunlight. A few years ago, flipdisc displays used to be very common in buses, trains etc. Then LEDs got better and the niche vanished...

nirav723 months ago

It was going to happen, these flip displays with moving parts probably required maintenance. Also higher energy consumption. Not to mention the noise. I still remember the noise when they use to have these in trains and airports.

glitcher3 months ago

I always liked the clickity sounds of those panels updating!

beatboxrevival3 months ago

I've been coveting a Vestaboard, but this seems like a more interesting alternative. Thanks for the guide!

jschulenklopper3 months ago

Owen McAteer, https://motus.art/, @motus_art did something similar with the flip-dot displays from AlfaZeta. I have no stake, but I'm a fan of his work.

His code can be found at https://github.com/owenmcateer/FlipDots.

tivert3 months ago

> 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.

elaus3 months ago

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...

lanewinfield3 months ago

Each board is, as of this year, 220 EUR per 7x28 panel. Still expensive! But specialized.

yyyfb3 months ago

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.

wrs3 months ago

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.”

yyyfb3 months ago

I'd be fine with power, I'm running off a raspberry pi that can do all this easily. Still I'm not sure how I'd go about plugging something like PIXI onto a custom display? It draws to a screen from a browser, and I need it to draw to a memory buffer...

beatboxrevival3 months ago

You should be able to use the library mentioned in the article with a few small modifications to connect to your device.

brobdingnag_pp3 months ago

[dead]

LordShredda3 months ago

I think the javascript here plays a rather small part in the entire assembly.

nico3 months ago

This looks amazingly cool. Love the old school “analog” feel of it

Thank you for sharing

nayuki3 months ago

Well, it's mechanical but still digital. Each pixel is either on or off. Locations are discrete and finite.

oops3 months ago

> Each pixel is either on or off.

Or traveling. I imagine if you wanted to you could position the disc at any point between “on” and “off” by constantly flipping it back and forth.

garfieldnate3 months ago

So happy to find out what this is! The Meow Wolf in Denver has a huge one of these in the entrance way and I thought it would really fun to build one myself. They have this wonderful clickiness to them, a mesmerizing display both modern- and ancient-feeling.

helsinkiandrew3 months ago

Mike from Mikes Electric Stuff on YouTube, did a very interesting 25 minute video deep dive on flipdots - how they work, patent details, how to drive and get the best performance, etc:

https://www.youtube.com/watch?v=u26N-pQY2U4

IIAOPSW3 months ago

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.

voidUpdate3 months ago

I've seen people making custom ones themselves, and its on my todo list of projects. https://youtu.be/K_UEkRFP7fs was where I got the idea from, but many videos exist

dmd3 months ago

I've got one of these too, albeit much lower resolution. I bought it as a Krush Flip Clock at CES 2016, and wrote a Python driver for it. Looks like it's the same exact protocol.

https://github.com/dmd/clack

cperry3 months ago

Amazing work, I've long dreamed of building some sort of magical chyron or ticker using flip discs.

simpsokaop3 months ago

Thanks!! With scenes you could add a ticker for something to this board.

noisy_boy3 months ago

I have looking for a cheap low-res 18in x 10in display so that I can display stuff to it via Python using a raspberry pi; this is very interesting but its a bit too big and expensive.

tailspin20193 months ago

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.

simpsokaop3 months ago

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.

hex4def63 months ago

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.

scosman3 months ago

Love this.

Reminds me of the “flip flap” boards in old train stations. Like https://www.vestaboard.com/

yojo3 months ago

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.

wrs3 months ago

I wish they would just fake the sound effect (hey, electric cars do it).

seanvelasco3 months ago

reminds me of a certain art installation at Changi Airport in Singapore. it was the first cool thing I saw in that country

[deleted]3 months agocollapsed

dehugger3 months ago

This is incredibly cool! Does the video audio amplify the sound of the discs flipping or are they really that loud?

simpsokaop3 months ago

They can be a little loud, but I find it pretty soothing, tbh. It's sort of like a rain storm.

GalaxyNova3 months ago

I've always wanted to build something like this, but I have no idea where to get the actual flipdiscs.

ElCapitanMarkla3 months ago

Love this. I have 2 blank walls in my new office which could do with something like this

nirav723 months ago

This is neat. But wondering what the power draw for something like this would be?

olalonde3 months ago

Just so you know, the links in the contact section appear to be broken.

simpsokaop3 months ago

Ok, thanks for the heads up!!

wferrell3 months ago

Kath - so cool to see this is you! What a great project. Well done.

simpsokaop3 months ago

Hey hey! Thank you!!

ape43 months ago

Whats the expected lifetime for a flipdisc display like that

simpsokaop3 months ago

over 150 million operations on average -- from alfazeta documentation

its_ethan3 months ago

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.

mmcclure3 months ago

> Keeping low numer of controllers on one data line, allows to drive these displays with an increadible speed of 15 frames per second (black – to – white).

From Alfazeta's page (including the typos). 15 frames per second feels pretty wild, but would also, unfortunately, change this math pretty considerably if you ran it full tilt.

its_ethan3 months ago

I had originally assumed 15 fps but it did feel a bit too fast.. BUT a 15 fps video being displayed in black and white doesn't mean the tiles will "flip" 15 times per second - a 15fps video could still mean that a tile doesn't flip at all for 50 "frames".

It does leave you exposed to the risk of a video where one of these does flip like 12 times in a second for like 20 seconds or something.

You could probably analyze whatever video is being played to calculate some kind of like "risk" value or "expected-lifetime-decrease" value to at least better understand what the impact is of the video being played. All that goes out the window when you do the sort of real-time mirroring shown in the article.

eterevsky3 months ago

I was expecting Bad Apple on flipdiscs.

notatoad3 months ago

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 500€ (VAT and shipping included).

https://hackaday.io/project/159415-flip-dot-display-diy-cont...

carb3 months ago

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!

€4500 is quite the pill to swallow (unless prices have gotten cheaper since that 2018 Hackaday project)

simpsokaop3 months ago

I paid a fraction of that. They'll come up on eBay every once in a while.

carb3 months ago

great to hear!

anfractuosity3 months ago

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 £50.

[deleted]3 months agocollapsed

imzadi3 months ago

How do they have no moving parts?

simpsokaop3 months ago

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.

crazygringo3 months ago

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.

beatboxrevival3 months ago

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.

crazygringo3 months ago

> 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.)

simpsokaop3 months ago

Thanks for the feedback. I've updated the article.

[deleted]3 months agocollapsed

risenshinetech3 months ago

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?

lucianbr3 months ago

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.

risenshinetech3 months ago

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.

simpsokaop3 months ago

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!

simpsokaop3 months ago

Updated to make this more clear! Sorry for the confusion.

dylan6043 months ago

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.

omneity3 months ago

One could argue flipping doesn't change X, Y nor Z coordinates :)

adolph3 months ago

Seems koan-ish:

  What is the movement of a stone standing still?

  What is the rolling rock that goes nowhere?

hatthew3 months ago

One could argue it changes the θ coordinate

endisneigh3 months ago

Probably best to say mechanical movement.

[deleted]3 months agocollapsed

jstanley3 months ago

What is up with the URL?

simpsokaop3 months ago

Sorry, I don't know how that got added. It's https://flipdisc.io/

pvg3 months ago

It's this misline in your html

<link rel="canonical" href="http://localhost:4321/">

HN extracts these.

dang3 months ago

And handles them inappropriately, it seems, since we converted the URL to https://flipdisc.io/http://localhost:4321/.

I've fixed it now.

simpsokaop3 months ago

Cool, thanks! I'll update that.

qmarchi3 months ago

Excellent question, it should probably be changed to https://flipdisc.io/ (truncating everything after the first /)

[deleted]3 months agocollapsed

rhaps0dy3 months ago

> Flip displays are an interesting alternative. They have no moving parts,

What? The display is made almost entirely of moving discs.

lucianbr3 months ago

Except for the moving parts, there are no moving parts. What's unclear? :)

simpsokaop3 months ago

See discussion below. I just need to update the copy.

[deleted]3 months agocollapsed

cannibalXxx3 months ago

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