HN comments for: LED Matrix Earrings

This is very cool and I know a LOT of people who would buy and wear these. If you productized these (possibly make them rechargeable and simply way to program the LEDs) they would definitely sell.

the weight might start getting bit of a problem here too? Hiding the battery somewhere behind ear could help, but ruins the conceptual elegance

Probably not worth the effort. Some women wear pretty large earrings[0] without too much trouble, after all.

[0]: https://www.regalrose.co.uk/products/glory-huge-star-hoop-ea...

Not without any trouble though https://www.self.com/story/heavy-earrings-stretch-out-your-e...

The patient in question wore heavy earrings for years. Wearing moderately-heavy LED earrings every once in a blue moon isn't comparable to that.

Usually they are large but surprisingly light, made from very thin metal foil.

Hairclip the battery with tiny wires behind the ear. You could put the controller there too if you wanted something fancier

I'm not sure about the rechargeable aspect, but for programmability you could use a small IR receiver placed in the center of the LED array. You really only need a one way data transmission and something like Bluetooth is overkill.

Could use an optical sensor like the Timex Datalink watches from the 90s[1]

Could set the earrings on a phone screen and transfer the patterns over. Sounds like a fun project.

1: https://en.m.wikipedia.org/wiki/Timex_Datalink

LEDs are actually sensitive to light themselves so with some wizardy you might not even need separate sensor

I love simple light-based data transmission stuff. I've seen it included in things like guitar pedals that have just a few config bits that someone might want to change infrequently. An app to change some settings can be as simple as just a little webpage! So simple!

Here's a (tiny) demo of this for my PCB business card project from years ago [1]. If IIRC this proof of concept was as simple as using a phototransitor on a GPIO connected to the UART peripheral with a very low baud rate.

[1]: https://www.matt.egan.me/entry/electronic-business-card-pt3#...

Now that you made that connection:

Concerts with audience-worn LED bracelets regularly shoot out LED floodlights to the IR sensors on each wrist. Being able to do something similar on people’s ears could be cool.

If you use visible light, then one can use a phone (screen) to blink the pattern to transmit data. An LED can also be used as the sensing element, just need access to both anode and cathode. Charge the LED and measure the discharge time - it is dependent on light in.

Fortunately for the OP, that part's really easy; Simply wait for the tech news outlets to pick up this story, then sit back and wait for them to start showing up on Temu.

Like this? https://www.temu.com/2pcs-led-earrings-illuminated-with-whit...

Those appear to be static. The ear rings in the OP are way cooler. But damn, for 4 dollars? I didn't expect even those to be that cheap.

I just got a few for my daughter, on Ali Express they are less than $2!

In parts. But now automate the production part. Will cost you at least 50k to get done. Not an extreme amount, but still.

You probably didn't watch the video. These are exactly the earrings used in the video to create the matrix LED ones. These earrings are just a fake jewel with an LED back light.

The article showcases a programable LED matrix, which opens up a lot more possibilities.

I'm afraid they will eventually be mainstream, because we definitely need more e-wastes for vanity purpose…

would definitely buy these!

I would if I could program them relatively easily. And if there were other colors then just red LEDs.

Multi-color is probably not really possible at a reasonable price point because you'd need twice as many vias and traces in the same space for RGB compared to just R. You _can_ get it manufactured, just not in low quantities at a price anyone would be willing to pay. There are 1.1x1.1mm addressable LEDs available[0] which should be quite doable, but those require quite a high voltage and have an unacceptably high idle power consumption: a 52-LED matrix would draw 15mA with all the LEDs off!

As to single-color non-red: the main advantage of red LEDs is that they can operate on a very low voltage. The exact same board with blue LEDs would have a significantly shorter battery life - if it's even possible at all. These earrings are probably using two SR521 batteries, which start at about 1.55V and discharge to about 1V[1] - so the earring is operating on 3.1V to 2V. You can get red LEDs which work with as little as 1.7V, but blue LEDs need about 3V to operate _at all_. You'd either have about 1/3rd of the battery life, or you'd have to add a third battery.

[0]: https://www.adafruit.com/product/5849

[1]: https://img5083.weyesimg.com/uploads/xtk5s4z6.allweyes.com/i...

Boost circuits are common for driving LEDs, for example a joule thief would be perfect for running this on fewer batteries.

True, but that's still going to consume more energy - not to mention the boost circuit probably taking up more space than the additional battery.

It looks like you can get reasonable SMD boost chips and pack them and their entire support infra in <10mm https://hhtronik.com/product/uboost/ which is about the same as two batteries as used in this project.

true, but it's challenging to get a boost converter, even a very simple one like a joule thief, into the space of this earring; i think it's too small for a millihenry. using a larger number of smaller batteries might be a better option

As for multi-color individual green and blue leds could be just mixed in.

Do blue leds consume significantly more power too for the same brightness, or only their voltage is higher?

Great question! Each individual photon carries more energy, so I'd assume they do indeed consume more overall power. But maybe eye sensitivity compensates for that?

Same. These could easily sell for a few hundred USD.

I'd like these as cuff links. Imagine it as a status symbol!

Only if made by Apple.

The cuff-links would turn into green bubbles when you're near "poor" people (by detecting Bluetooth MAC addresses of non-Apple smartphones)

For now.

Seiko invented the amazing quartz watch which was a marvelous invention of timekeeping with a crystal rather than mechanical links. Now a quartz watch is a sure sign of a cheap commodity. LED cuff links will be outdated quickly, probably less than a few weeks, maybe even after the first few wears it would be gaudy.

wp sez

The National Bureau of Standards (now NIST) based the time standard of the US on quartz clocks between the 1930s and the 1960s, after which it transitioned to atomic clocks.[43] In 1953, Longines deployed the first quartz movement.[44] The wider use of quartz clock technology had to await the development of cheap semiconductor digital logic in the 1960s. ... In 1966, prototypes of the world's first quartz pocket watch were unveiled by Seiko and Longines in the Neuchâtel Observatory's 1966 competition.

but certainly it is common for today's technological miracle to become taken for granted tomorrow

At this point it seems like the biggest limiting factor of scale is the vias, not the LEDs themselves. If they made LEDs with 3 pads, where the outer 2 pads are connected together, you could make a matrix on a single-sided board with no vias.

I wonder how it would look to connect the columns with 0201 zero-ohm resistors between the LEDs (jumping over the rows lines). If you want a square pixel pitch it might work out nicely.

You don't really have the clearance for that. The gap between the two pads of the resistor should be at most 0.3mm, and more realistically 0.2mm - any larger and they're going to tombstone. 0.1mm traces with 0.1mm clearance are manufacturable so it could fit in a 0.3mm gap, but realistically you probably want to do 0.15mm traces & clearance to keep the cost acceptable.

For one-off, I wonder if you could just glue the leds together and hand-wire (very carefully) with some magnet-wire. Throw in some kapton tape to insulate everything.

How about OLED microdisplays? You could have full HD and thousands of nits of brightness.

Design-wise I liked the industrial more, it was more cyberpunk. But this is very neat too.

What I find pretty crazy is that there are .65x.65mm RGB LEDs, equal to the long side of articles LEDs squared. They are also only .25mm thick, that's same as few sheets of paper. One cyberpunk look I'm thinking you could do with those is just to glue them on your face and blend in with makeup; I'm sure someone could do fancy things here. Wire you can get pretty much as thin as you possibly want.

Five-ten years ago there was a thing for LED eyelashes - glued to your upper eyelid, super-fine wire running to a battery by your ear. I'm not sure how they worked electrically, but the fancier ones appeared to have individually addressable LEDs along the upper eyelid. I thought they looked cool.

Huh, cool, I completely missed that trend. From electronics point of view I'd assume they work the same as any other regular led strips, just miniaturized. Now I'm tempted to just buy some and the figure out an occasion to wear them

I got a few recently for model train lighting; ten bucks on Amazon. There's a thin wire that goes to a battery you wear behind your neck like a necklace. https://www.amazon.com/JZSMY-Luminous-Flashing-Eyelashes-Hal...

Any video that references Mike Harrison as inspiration is all right with me. https://electricstuff.co.uk/

I don't understand your comment relation with the posted article

The video in the article detailing the build shows Mike Harrison's badge in the intro that they used as a reference for their prototypes.

Exactly that! Blink and you'll miss it though, hence my post with a link for anyone who is interested.

The led trails photo got me thinking you could make some cool persistence of vision stuff with these. As long as the wearer is going fast enough.

A thin diffuser layer would make the LED image clearer. I tried it with the Arduino Uno R4 LEDs, covering them with the diffuser layer (the thin flexi plastic, slightly foggy) from old phone screen backlight.

Also ripe for use in any number of accessories. You could plausibly decorate just about any kind of clothing or jewelry with these if you make them detachable. You could probably have a whole glowing silhouette of your body when you dance, if you space them out like the markers on those motion capture suits.

1999 hangar raves would have loved these.

Phosphor-impregnated epoxy blob?

I will declare my self successful in life if my website looks like the author's https://mitxela.com/projects page

I wish I had as much competence, energy, time, and machines than him !

I know right, so many interesting projects. And many of them complete!

I wonder what the smallest circular OLED display is. There are 01005 LEDs (the next size down from the 0201's used here) but at that point an OLED display is essentially the same thing.

indium gallium arsenide and gallium nitride probably have a much longer lifetime than oled and will probably withstand higher temperatures (though the encapsulating resin may not)

I see models down to 0.5" (12.7mm) but they all seem to have large connectors you'd have to work to hide/connect an microcontroller to.

The last thing anybody concerned about their looks wants is to have strong side light shining up close on all the imperfections, scars, bumps and overall messy skin that looked so nice and smooth before.

Guys really don't want to see woman's pores and pimples 3D facial structure. Or anybody's else for that matter.

Must not want anyone kissing them, then. Because once you're in that close nothing is hidden anymore.

Could you include ir LEDs to blind cameras? Is that a thing?

With the size of that battery, it might work for a second or two.

It's an impressive electronics project, but is it an earring anyone would want to wear?

Are you kidding me? Just about every STEM gal would pay a pretty penny for a set of those!

The industrial[0] is a bit too obscure, the led-ring variant[1] is a little underwhelming, but a full LED matrix? Absolutely breathtaking.

[0]: https://mitxela.com/projects/scaffold

[1]: https://mitxela.com/projects/charliestar

can confirm, my ears aren't pierced but this is probably the most envious I've ever been of a pair of earrings

Target demographic: raver girls

Also check his YouTube channel to see them in action and for more background information: https://youtu.be/CHoGIvOi-jw

fashion victims will fall for that.

Pretty cool to see 2x2 layer sandwich of pcbs. It’s going to be cheaper than 1-2-1 pcb at small scale. That’s the same thing Apple does.

I saw that yesterday and immediately googled if I could buy a similar led matrix for making a set. And I'm a man that has never wear any earrings and do not plan to wear some. So you can say that the marker exists

I wonder how much the "staggered blind vias" PCB would have been.

I ended up doodling up some ideas [1] based off this, with a pendant, OLED display, and a separate battery holder hooked to the ears coming to mind. A similar design would also be cool for earbuds and IEMs especially if the lights could be synchronized to the music.

(Seriously though, everyone should learn how to sketch the designs in their head. You don't have to be good, you just have to be adequate enough to get your point across).

1. https://i.ibb.co/wwTKNJ2/image.jpg

Awesome!

I have circuit plugs, LED matrix plugs would be the next level :D

I am impressed! It’s startling how small things have gotten

I'd be interested to see an algorithm for the blinkenlights effect he demos.

I was just watching this!

Super cool.

wowee, Mitxela is a really fun rabbithole!!

I don't know if it's feasible at this scale, but a version that could optionally animate or pulse in sync with sound (music) would be a big hit in nightclubs.

Very cool. I could see these being popular if sold. Expect to see these on Ali or Temu by the end of the week.

Very happy to see someone did this, because I had the same idea many years ago, but it seemed infeasible.

Look at Ayke's approach for another opens source earring style, using RGB LEDs and running TinyGo: https://github.com/aykevl/things/tree/master/earring-ring

https://hachyderm.io/@ayke/110318083332958798