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basil-rash
amluto
To be clear, this is a 38kHz modulated IR system, and it’s not likely to work like a DMX light.
38kHz IR is an extremely mature technology. The transmit and receive sides are made in huge volumes, complete with integrated modulators and demodulators. There’s a receiver in basically every piece of consumer A/V equipment and a transmitter in almost every remote control. You used to be able to buy them at Radio Shack!
krisoft
> it’s not likely to work like a DMX light
That is not what the manufacturer says: “Our wash works with a standard professional lighting rigging yoke and DMX 512.” [1]
Wash is the name they use for the lamp which sends the controlling signal.
amluto
Huh, I guess they are sweeping their IR transmitter around just like a visible light. I suppose one could map all the effects one intends to use onto DMX channels. I imagine that actual selection of those effects is done out of band.
okrad
They have a Wand product that can be used to dynamically paint the audience receivers from the stage. Have yet to see this live
hi-v-rocknroll
The HP 48G/GX calculator had a learning and preprogrammed IR remote control app that used its extremely powerful IR LED to could control TVs around 60-100' / 20-30m away.
HeyLaughingBoy
I actually have one still in the original blister pack with the Radio Shack backing :-)
stavros
I had the same reaction, this is a really hard problem, unless you solve it the way they did. Ingenious.
topherjaynes
I was at the Tampa concert last year, and I was so distracted by trying to figure out how they controlled the wristbands. They were randomly handed out at the door, and I had no idea what seat I was in. I went through the scenario to flash sectors to see where they were located and build a grid, but when I got home, I was floored at the IR solution. It was so simple.
Waterluvian
I also appreciate when designers recognize “this is the kind of thing where a 95% hit rate is fine.”
preinheimer
I think there’s also the whole “the people with the wrist bands -want- them to work” part. Which is super helpful.
Yes, you could hide your band under your hand, now it’s not glowing like everyone else’s… congrats you feel left out.
Cthulhu_
And it isn't secure, but, it doesn't have to be. In theory someone can bring a high strength IR beamer thingy to an arena and draw penises or offensive texts on people's bracelets, but that's a manageable risk. Protecting against that would make the devices much more expensive.
I mean the components in this one are a few bucks at most, right?
xg15
Yeah. My first thought was "have fun smuggling any kind of bulky electrical equipment into a Taylor Swift concert, let alone a stage light. Security will not even be mad."
But on second thought, I think there might be an actual scenario to worry about: Activists hijacking the system to show political messages.
For that they'd "only" have to beam the IR to a small spot of the room (but with much higher "resolution" than the normal effects). As long as the symbol/text/whatever is still legible enough that people recognize it and can take pictures of it, they'd have achieved their objective.
Something like this might be possible with a much weaker, purpose-built emitter that could be hidden under clothing. Too much risk and effort for some dumb dick joke, but thinkable if people have some kind of political motivation.
As a "bonus", the first blame would probably fall on the unfortunate people whose wristbands lighted up with the message, while the real perpetrators - the ones with the emitter - remained hidden.
There is an easy fix as well though: As the system "paints" with digital signals and not light, the old lighting rule that colors mix only additively doesn't hold anymore - so you could add a "don't light up for the next 10 seconds" command to the wristbands and just have the stage beam that command continously whenever no effect is wanted.
Taniwha
I built this: http://www.moonbaseotago.com/cheaprf/dev_playa1.png 10+ years ago = it uses a CC2533 RF/CPU zigbee core and forms a mesh net (it does SUOTA that way too) - we designed it for Burning Man but never swung the funding for tens of thousands of them
You can find more here: http://www.moonbaseotago.com/cheaprf/
CPLX
If you watch the video at the top of the article it looks like they actually have a couple options. Infared is one, but there's also bluetooth and RF control as well, and there's video of a feature where people are entering their seat information to participate.
epmatsw
I spent an honestly embarrassing amount of time at the first show I went to trying to figure out how they'd managed it.
grogenaut
At the first show I was at that had them, The International 5 in Seattle, I figured out they were IR very quickly by putting one in my backpack and seeing it didn't react when all the others did but did react as soon as I pulled it out (cloth backpack).
I then prime now'd a univeral remote to the arena. I had arena wifi for my work but I was in the stands. That didn't work (didn't pick up a signal). So that night I diassembled it and verfied it was basically a moulded wristband, micro, ir, leds, battery and connectors. so I next day'd an IR Toy to the arena. I was able to read a signal but couldn't reproduce it. It was kinda hard to live code during the event and my batteries kept dying.
I tried again the next year but got bored after that. It was annoying to have the setup at the ready when they flashed the lights especially as that was usually during the biggest moments of action. So I just sat back and enjoyed the show.
hencq
I initially read over what show this was, so I was picturing you live coding this during a Taylor Swift concert.
HeyLaughingBoy
> I then prime now'd a univeral remote to the arena
I confess that I had to read this three times before I got it. And now I'm amazed at the times we live in. I was impressed enough that I live on a farm in the middle of nowhere, but I can order something on Amazon and possibly get it the same day, but being able to order something delivered to a public place and know that it will get there within hours just blows my mind.
For all the bad things you can say about Amazon, achieving this level of logistics is insane.
aeternum
This works great until someone comes to the show with flashlight augmented with a simple chip to send the right frequency and does his/her own crowd painting :D
krisoft
Yeah the company making the bands also makes that flashlight: https://pixmob.com/stories/pixmob-portable-transmitter
They call it a portable transmitter.
ada1981
Can we buy one?
I could see a venue renting these to people for the night. They could outfit them with a kill switch remotely if people abuse it.
Or have them tethered in the VIP areas.
eastdakota
I may have gone to the Taylor Swift show in Lisbon, wondered how they were able to precisely control these without carefully handing them out, gathered a few from my fellow concert goers, and presented them to John last night over dinner with a challenge to figure it out. All my guesses were more complicated than the actual answer.
jgrahamc
Thank you for the nerd-snipe, but thank goodness others had done the reverse engineering otherwise this would have been a long night...
eastdakota
I still wonder if it would be possible for a rogue concert goer to hijack a side of the stadium to display something. All sorts of trouble you could cause.
stavros
Well, it would, if you had a 30W infrared spotlight with you.
eastdakota
Also wonder if there’s a buffer overflow attack or some command that could cause them to get stuck flashing rapidly or something that would be really annoying. Surprised by the lack of encryption or any security on devices like these. For a long time there was no encryption on the Shure wireless mics most big shows use. Hopefully that’s been corrected as that seems like a real way you could cause (dangerous) problems at an event like a stadium concert.
celso
This reminds me of TV-B-Gone https://www.tvbgone.com/
caminante
That was some entertainment arbitrage.
A friend told me Swift tickets + flights to PT were cheaper than local US tickets...and you get Lisbon!
mercutio2
Yup. My family is heading to Vienna for the same reason this summer. I wonder what fraction of attendees will be US residents?
0xbs0d
I live in Denmark and I've been to Stockholm and I'll be going to Vienna as well. There was a lot of Americans in Sweden for those three tour dates. Not as much as Paris or (probably) London but still very noticeable specially at restaurants, museums and hotels. I think for Paris it was something like 20% of Americans.
Rossimac
I took mine apart mid-show to figure out how it's doing it's thing. Brilliantly applied tech, but I couldn't help but think of the e-waste from those fans who don't cherish something like this enough to keep as a memento.
Edit: seeing others commenting on sustainability and pointing towards their website. Fair enough. Good experience had and it's not the worst.
xpe
It seems plausible that some combination of the following would reduce waste considerably: (i) a donation box at the exit; (ii) a trade-in station offering $2* or a bottle of water.
* I don't know if $2 is close to reasonable.
guappa
The 1st thing i thought when I opened the article: "what a useless mass production of garbage"
diydsp
I contracted for them a number of years ago... probably one of their biggest early shows for Arcade Fire... to address sustainability at the time, they had a microphone inside their devices. At the end of the show, they sent a special command that switched it over into "color organ" mode so you could hold it up to your stereo at home and see a trippy light show! (I wrote the audio-to-trippy rgb led code). It was cool, but even better they're re-using them now. It is a great little company in a huge old industrial factory in Montreal. Hi, Vincent!
phkahler
>> At the end of the show, they sent a special command that switched it over into "color organ" mode so you could hold it up to your stereo at home and see a trippy light show!
That is one of the most awesome things I've read - a company making an attempt at increasing the usefulness of the product after it serves their intended purpose. Such a sharp contrast to the norm of bricking things that might be useful to people just because the company in no longer interested.
vinlc
Yesssssss! Good times and sleepless nights :) Hi Noah <3
brenns10
At the end of the show there are boxes to return the wristband so it can be reused/recycled. The vast majority return them, except a small portion who may keep it as a souvenir or to tear it down.
codetrotter
Nice write up!
I would also add that OP should spell out the text from the circuit board in their blog post, so that people who pick one apart and Google the text can also find this blog post.
Pixmob PALM V2.6r1
(c) 20230629
Designed with ♥ (love) in MontréalYlpertnodi
Three cheers for the date format.
rrr_oh_man
What’s so special about February 20, 2030 (6:29am)?
nfriedly
Putting the year first makes it unambiguous. Some places do month-day-year, and other places do day-month-year, so any date up to the 12th of the month can be confused. But if the year comes first then it's always year-month-day.
Also, a 4-digit year is important here.
undefined
Wowfunhappy
...How are you parsing the timestamp? I can't get it to match.
jgrahamc
Done
I_o_IllI__o_I
That's smart bro, thanks for the suggestion. I'm sure OP will appreciate it. Will those sort of simple changes even be able to make much of a difference compared to those heavily SEO optimised blogspam sites though?
TeMPOraL
Surprisingly, yes. SEO blogspam rarely optimizes for details this specific, unless it's mainstream technology (like, idk. version numbers on Windows or iPhones).
shiandow
Provided we still have search engines that can search for literal text a few years from now, I think it should work.
geor9e
Here's a video of the high powered invisible IR searchlights projecting the colors onto the crowd (looks like its triggering the RAINBOW_MOTION fade from the github link pixmob_special.ir) https://www.tiktok.com/@micahstgeorge2/video/723551076132861...
zzzeek
We spent a week in Disney World last month where we used Disney Magic Bands. I thought they were a total blast, they serve as your room key, ride / park passes, then they are lighting up and buzzing all over the park when interactive things are nearby. During fireworks shows they add their own light show based on your proximity to the event.
Sure, they are also tracking our every step throughout the park but this felt like a good thing, like if our 9 year old got lost, his band would totally identify who he's supposed to be with and where we are.
Animats
Can they apply an electric shock to the user if they do something Disney doesn't like?
FridgeSeal
Conversations about DRM and Copyright will shock the user into submission until the Mouse’s elite lawyer-hitmen can arrive to beat you before suing you into the ground.
adolph
Something conceptually similar exists: Shock Clock - The Ultimate Silent Alarm for Heavy Sleepers, Hard of Hearing, Couples, and Shift Workers - Wake Up on Time, Create Better Habits
https://www.amazon.com/dp/B01EZ77IOY
I've been able to train myself to wake with a much less expensive simple vibrating wristband.
cooper_ganglia
I bought that thing and I swear I started sleeping through the shocks. I'm too heavy a sleeper. A body at rest remains at rest, indeed, Sir Newton.
glitchc
Apparently punching Mickey doesn't count [1].
[1] https://insidethemagic.net/2023/03/world-renowned-tiktoker-d...
SV_BubbleTime
I want the old internet back, not whatever this is supposed to be.
barbazoo
What happens after the vacation, do they reuse them or do they go in the trash?
codazoda
You keep them for the next trip to Disneyland or a Disney Cruise or share them with friends who are doing the same.
I only charge mine about four times a year, so I doubt the batteries will last too long, but I’ve been surprised so far.
Note that they have at least two models and they haven’t always interchangeable, so check before you go.
zzzeek
Pretty sure we can use them for our next trip. They aren't like cheap, we had to buy them for like 30 bucks each or something
TheRealNGenius
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doctorhandshake
This effect is really cool but I can’t help but think of the huge piles of e-waste it must produce after every show as these wristbands go in the bin.
nickthegreek
Pretty sure they have specific collection bins. Many keep them as a memento of the experience though.
wrboyce
Coldplay had similar wristbands when I saw them in Wembley last year and a big thing about their tour was sustainability. They definitely had collection bins for them at the exits, but I kept mine to satisfy my geeky curiosity.
chrisldgk
Turns out it’s the same company that makes the wristbands for the Coldplay shows, so chances are it’s the exact same here
tonymet
the CEO is very humble . it's a genius solution. Though, we shouldn't be talking about IR & FM as "old school" solutions. The best solution is whatever requires the least resources, lasts the longest, while providing the most creativity & utility. That should be the golden rule of engineering.
Software engineers especially tend to dwell on overly complex solutions with gps, 5g, sensors, ARM cpus , etc -- and dismiss a mechanical implementation or simple circuit as "primitive" or "old school" / "old fashioned".
Remember that every transistor & circuit is a point of failure. A mechanical solution can last 100 years (like my typewriters which still feel brand new). Simple circuits running industrial machines also last 100+ years.
Complex ICs are lucky to last a few years, and often have high failure rates in operation. Why does a trashcan or toaster need an IC?
This isn't a rant, it's really to highlight this company's amazing work and inspire more engineers to be proud of elegant solutions once again.
wodenokoto
Meanwhile the Black Pink glowsticks, which retails at nearly $100, have Bluetooth and require firmware updates before a new concert.
Taylor Swifts' solution seems a bit more crowd friendly in my oppinion.
mbirth
Big Clive did analyse a similar Pixmob wristband here:
fergie
I'm surprised we don't see more of Big Clive on HN
herunan
In the video, the CEO of Pixmob seems like a nice, humble guy: “the wristbands are really stupid, but we like it that way.”
jezzamon
That sounds more like a boast to my ears. It's like if someone solves a complicated software problem with a simple (in other words, stupid) system.
Not saying he sounds arrogant. Just describing good engineering.
thedudeabides97
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squarefoot
Back in the day smartphones with GPS became widespread, I had a more convoluted but much cheaper idea that involved no external hardware: an app that would register to a database with seat position, then refine it using GPS (in case someone is changing seat or wandering around), then it would have been just a matter of keeping the phone in sight using a phone necklace: the app would download its sequence to be played (each screen would essentially act as a big RGB pixel) then synchronize the pattern against NTP+GPS precise timing, then wait for the right moment to play it. Phone in closed spaces could not have used GPS, so they would rely on seat registration, although I was exploring the idea to use Bluetooth or ad-hoc WiFi links to synchronize with nearby devices to detect movement (that is, if I have say 5 devices very close, their seats match while mine doesn't, very likely I'm the one who moved elsewhere and my phone would update position accordingly). Probably too complicated to gain success, but I didn't even try to develop it beyond the simple idea; laziness and other problems sucked me away from any creative work.
TeMPOraL
I feel this is doomed to fail for a simple reason: phones are too janky for this. Even flagships can't be relied to respond in real-time-ish (under a second); there's too much bloat in both the apps and the OS itself. And phones most people sport have weaker hardware (sometimes even underspecced for the expected load right at the time of purchase). I imagine the resulting stadium-scale video would be glitchy AF - even syncing to wall time, you'd have pixels freezing randomly all over the place.
ipqk
If you watch the linked video, the kpop concerts basically do that. You bring your own light, pair it via bluetooth, and specify your seat.
taylorfinley
Don't want to ask you your name or location to preserve privacy, but do you happen to live near what used to be a really cool coffee shop, and do you have an awesome garage with a plasma cutter? If so I think you told me about this project a decade ago while we built a little backyard forge!
squarefoot
Central Italy here, and no, unfortunately I never lived near a cool coffee shop and I never had a garage with a plasma cutter, but talked about the idea to some friends roughly in 2011 so it is possible that the word traveled around.
taylorfinley
My buddy was working on exactly the same project around then in Austin tx. He was trying to make it as a web app with access to location permissions, where the page's background color would change for each individual pixel in the virtual display. Concertgoers would visit the url and their phone would become a pixel in the screen. He was trying to figure out how to get better location resolution when we talked about it, sounds like you guys had similar ideas and both discovered the implementation was trickier than it initially seemed it would be. I wonder how many other folks worked on that idea around that time?
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What a delightfully simple solution! I have to imagine if I were given this problem I would muck it all up with wristbands assigned to seats and a 5G/IOT network needing to be installed at every stadium and custom control logic needing to be written and customized for every stadium…
Whereas they just hook up an IR lamp and use the exact same lighting control procedures every stage tech knows blindfolded. Brilliant!