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.
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!
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!
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.
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.
The intention is likely that the transmitter takes DMX and sends out 38kHz IR, and the whole system of searchlight and individual armbands collectively becomes a DMX lighting. The optical wireless link part is an internal implementation detail.
I think the key thing is that IR allows the bands to work regardless of where the wristbands are located in the stadium. Additionally, they're probably using the IR to multiplex since the DMX 512 standard technically only supports 512 channels (which if each device uses a channel for color and channel for intensity, is only 256 supported devices).
With the IR technology, they are not addressing the individual lights. The bands just respond when IR splashes on them. The IR "spotlight" is just transmitting a command on repeat, and the bands display that one off command. DMX is just commanding the spot to move a certain way, and transmit a certain code.
They have a RF variant where they put the bands on each seat before the show. THOSE bands are individually addressed with RF, and their position known in advance to the setup. (If you move a band to another seat you'll mess it up). They have a special device that transmits RF across the whole venue. That device probably has a DMX hookup to take commands to transition to certain pre-programmed scenes and/or animations, and commands from a USB-connected PC.
There is a video showing the RF box with DMX input (and USB), and they talk about how they can control it from a standard lighting board.
https://i.imgur.com/Di09aD2.jpeg
It sounds like each band can be a part of (at least) 2 "groups", with the example showing groups 1-18 assigned to each stadium section, and 1-9 going all the way around from the first row to the highest/back row.
It's not hard to imagine that they've mapped each of those groups to a DMX channel, with the value indicating the color, and/or flash pattern, etc. Even if you're limited to 512 distinct groups (a single DMX universe), that's a lot of granularity. With that, any lighting designer/operator can use their console of choice to do scene and sequence programming -- no special training needed.
Yea, that sounds sane. The RF transmitter gets the DMX commands to groups, which then get translated to batches of RF bands, and then they just act on that.
I wonder if the RF system has enough bandwidth to show a movie or an animation at a decent frame rate, because that would be a neat effect.
IR has arbitrarily good spatial bandwidth — instead of a conventional moving light setup, it could be done like a projector — stick a DLP chip or an LED array at the focal plane. Then you could project a movie by literally projecting the movie as IR commands :)
I doubt the DMX part is coupled that closely to the IR. No one is bit-banging their IR protocol (or even its baseband) over DMX — even if it could work, the lighting console would need extremely special support to speak the protocol.
The DMX part would be like any other light: a pair of channels controls the coordinates to which the transmitter’s gimbal aims, one channel selects a color, one channel selects a command, a channel or two set some other parameters, etc. And the electronics in the transmitter unit convert all this to actual servo commands and to the encoded IR signal. There wouldn’t be a channel to select the active vs inactive state of the IR modulator, as entertaining as that would be. (DMX has a maximum frame rate of 44Hz. Following some links, the PixMob bits are 694.44 microseconds long. RS485 is plenty fast to carry the baseband signal, but DMX isn’t.)
(It’s been awhile, but I have operated DMX-controlled moving lights. And yes, of course I’m speculating.)
Isn't that exactly what numpad0 said? You're just agreeing with them.
guess they are sweeping their IR transmitter around just like a visible light
For very clever reasons: (from the article) Since they are projecting infrared with moveable projector they can sweep effects around the stadium, and cover the projector with cut outs to make things like hearts.
That sounds like the wrist bands will auto-off their light when they stop receiving the IR signal. That's certainly possible and very simple which translates to high reliability.
Why do you say it's "possible"? It's what they're actually doing. I think practically nobody in this thread actually watched the linked video that explains the technology.
1x channel for lamp brightness (likely pinned to "on" to provide constant power). 2x channels for pan (double fine). 2x channels for tilt. 1x channel for gobo rotation. 1x channel for gobo selection. 3x channels for standard color mix (RGB) are then sent to the modulator controlling the emitter. = 10x DMX channels per fixture. +1 maybe for focus depending on the style of fixture.
I'd bet good money that these things respond to standard DMX color codes. https://astera-led.com/wp-content/uploads/DMX-Values-for-com...
Want to hack the system? Look into whether they are using wireless DMX. Probably not, but if they are you might be able to take over the individual instruments. And I mean own them because such signals are never encrypted and the lamps won't be in a position to be rewired during the show.
I imagine that actual selection of those effects is done out of band.
This is a bit tiresome. :) Our conversation so far (paraphrasing)
You: “it is not DMX” Me: “it is DMX, here is the source” you: “i still imagine it is not”
Why is it so hard to believe that the effects are selected “in band” using DMX? You can imagine all you want all evidence points at that it is indeed just DMX.
Here is a video where they describe the system: https://youtu.be/CPqup9_I_dU?si=voLX4gAidOcOVJJ0
They have a Wand product that can be used to dynamically paint the audience receivers from the stage. Have yet to see this live
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.
I actually have one still in the original blister pack with the Radio Shack backing :-)
I also appreciate when designers recognize “this is the kind of thing where a 95% hit rate is fine.”
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?
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.
> But on second thought, I think there might be an actual scenario to worry about: Activists hijacking the system to show political messages.
Oh, the horror
There's something ironic about activists behaving like they somehow have the right to just be in people's way. As if the ends justify the means.
Rosa Parks, Henry David Thoreau and MLK disagree.
Seriously asking: did those three go around to existing events and hijack them? e.g. Did they jump on stage and grab the microphones, or did they block traffic so nobody could get through? Or did they threaten people with violence for passing through having contrary opinions?
My understanding after reading "King" by Jonathan Eig (a fantastic biography btw, highly recommend to everyone) is that they didn't do that kind of stuff. They marched alongside traffic and were so non-violent that they allowed themselves to be hit with dogs and high-pressure water hoses without responding.
Rosa Parks especially was not like most "activists" today. She clamly and peacefully kept her seat on the bus. Maybe the former Google employee activists who refused to leave the conference room would be similar here, though there are of course differences.
I consider myself an activist, and I believe strongly that people need to help raise awareness because there is far too much ignorance and apathy out there, but I agree with GP and siblings that many of the activists today are harming their own cause by being obnoxious. Raising awareness in an empathetic way is the right way to do it, not trying to bully people into agreeing.
Yes, this is exactly what they did.
Rosa Parks “got in the way” by not leaving a seat she wasn’t legally allowed to sit in. She disrupted the flow of the white passengers. Today people would say “why doesn’t she protest elsewhere? She’s just getting in the way of bus riders who are trying to get to work.”
Sit ins were lead by MLK. People would go into restaurants, order food, and refuse to leave until they were served, despite being told they had to leave because of (legal) race laws. Today they’d be told they should protest elsewhere, that there is a time and a place, and they are hurting their cause by creating a disturbance.
Thoreau explicitly states you have a moral obligation to oppose unjust laws, etc. and resist governments, etc.
Empathetic awareness raising is one way and often not sufficient.
Read kings Letter from a Birmingham Jail.
1) determine if an injustice is actually being committed 2) attempt to talk with those committing the injustice to resolve it 3) prepare spiritually for non-violent resistance to evil 4) engage in non-violent resistance, protest only after all other means are exhausted, be prepared to be beaten and do not fight back, and 4 is only a means to get back to 2 — to open negotiations and discussions to restore justice.
The greatest “harm” to a cause is often passive silence.
Sitting by and critiquing activists is often a pastime of folks who stand to benefit from the preservation of the status quo and who have no real desire for immediate change.
Here is King reading his Letter from Birmingham Jail.
Worth the 50 minutes to listen.
People are paying their own money to see these shows, protesting by ruining that experience is just going to piss people off and hurt your cause.
They must feel the pain for them to care.
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.
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
complex, expensive, difficult to deploy, doesn’t account for all factors (highly congested cellular networks are common in medium to high dense areas).
Reminds me of a few consultants I have had the “pleasure” to work with.
If you would have invented PixMob, why didn’t you invent PixMob?
To be fair, selling this thing seems harder than making it.
Goes to show it's not always about greed or malice. Sometimes overengineering is at least well-intentioned. (Following the money often helps you determine what caused it.)
I think over engineering comes from engineers catching shit from customers and managers that changed requirements after the fact.
Then on their next project those engineers get paranoid, and try to solve every problem before it happens.
The attributes you list are correct, but you’re being a little unfair with your pretty obvious implications of at the very least incompetence of not malice.
People get used to building with the tools in their tool belt. When a problem arises that is better served with another tool, especially when working at a “lower level”, even if it’s more simple overall which this clearly clearly is, many many people are blind to it. I guarantee that you’ve done the same thing at least once.
I think this is a highly uncharitable response to someone clearly trying to speak humbly and honestly of their instinct towards a solution they obviously then recognized would be inappropriate.
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
Good luck getting that past security...
Design it into a walking stick for someone with impaired vision.
That's a lot of work to get kicked out of a concert that you paid hundreds of dollars for.
Yeah the company making the bands also makes that flashlight: https://pixmob.com/stories/pixmob-portable-transmitter
They call it a portable transmitter.
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.
I spent an honestly embarrassing amount of time at the first show I went to trying to figure out how they'd managed it.
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.
I initially read over what show this was, so I was picturing you live coding this during a Taylor Swift concert.
They wouldn't let me bring in a laptop to eras sadly. And they're crimping my style at baseball games as well.
More evidence that we're losing our rights to general purpose computing!
(joking of course as that's not what is happening here. I am truly highly concerned about the loss of general purpose computing, but I also love poking fun at myself and group)
"wristbands assigned to seats and a 5G/IOT"
Not sure what a "5G/IOT network" is, nor what vaporware claims "wristbands assigned to seats".
Redcap [1], CAT-M1 [2] and NB-IoT [3] are 5G IOT technologies.
[1] https://en.wikipedia.org/wiki/5G_NR#NR-Light_/_RedCap
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.
I had the same reaction, this is a really hard problem, unless you solve it the way they did. Ingenious.
Yup, I love how simple the tech is at it's core. I would totally also overcomplicate it.
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/
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.
Is high power IR lamp safe for eyes?
- IR is just super red light. It's not significantly more dangerous as looking at a lightbulb can be, except human eyes cannot perceive IR and can't contract pupils or stare away by reflexes.
- UV is baby step towards X-rays. It's technically super blue light, but it's entering region where lights start splitting chemical bonds and bleaching stuffs like pathogens and human eyes.
- LASER is perfectly parallel beams of light. Because it's perfectly parallel and do not diverge, it behaves like sun under magnifying glass at all points in its path, which can be dangerous when the "sun" is high and "glass" focusing it tight.
High power IR lamp illuminating audiences from afar is almost safe as any searchlights. IR lasers can be dangerous. UV lamps are not so safe, UV lasers would be bad.
IR isn't just super red light, it's heat. Lol
It is the primary frequency of black body radiation at Earthly temperatures. But it is not the heat itself.
So is regular light, in that sense. The IR that's used for this kind of application is 'near infrared', which is much closer to light than the IR emitted by most warm objects.
It's light, and some animals can see it, just not us. https://en.wikipedia.org/wiki/Infrared has some pictures from the right kind of cameras and telescopes.
LASER is perfectly parallel beams of light. Because it's perfectly parallel and do not diverge, it behaves like sun under magnifying glass at all points in its path
To first approximation, in the typical situations regular people deal with lasers. Inverse square rule still applies; laser light does spread out with distance.
That nitpick aside, your description is spot on.
you mean like the sun?
The sun is decidedly unsafe for eyes.
(for ultraviolet light reasons)
IR as well.
The sun also emits in the visible wavelengths. Your eyes do not feel pain from bright lights due to the heat or similar. It's a response to brightness, in the visible spectrum. Without the visible component, there's no pain. With unhappy optical circumstances it could cook the retina because the pupil is dilated and there's no instinctive response to look away. Not sure how plausible those circumstances are. But I sure wouldn't put a 10 watt IR LED source right up to my eyeball.
https://arstechnica.com/health/2023/11/bored-ape-creator-say...
It can also happen with (the wrong type of) UV lights.
I looked into that for VR headset eye tracking, which uses IR lights plus cameras to see the eyes inside the dark headset.
Here someone did some calculations [0].
The International Commission on Non-Ionizing Radiation Protection's Guidelines of limits of exposure to broad-band incoherent optical radiation (0.38 to 3 µm)[1] states:
"To avoid thermal injury of the cornea and possible delayed effects on the lens of the eye (cataractogenesis), infrared radiation (780nm < > λ < > 3μm) should be limited to 100 W m⁻² (10 mW cm⁻²) for lengthy exposures (> 1000 s)"
0: https://docs.eyetrackvr.dev/getting_started/led_safety#about...
1 (pdf): https://docs.eyetrackvr.dev/safety/ICNIRP_optical_radiation....
Thanks. So that 30W lamp in another comment might be a safty hazzard if someone in close range stares at it and the beam is tightly focused.
You're right.
While we're at it, we should make sure no one goes up to the massive speaker system and puts their ear right up to the speaker cone too.
I guess this device can be modified to take visible red lights with some redesign, if you'll be really concerned with that.
Yes. The manual from the manufacturer recommends wearing specific green tinted safety glasses if you are standing closer than a meter to their transmitter while it is on.
The beam is not going to be tightly focused, if it needs to cover a big chunk of a stadium at once
Look at the heating bar on a 1200W electric radiator? That is a lot of infrared, often unshielded to the eyes.
When it's very narrowly concentrated on your eyes for an extend period of time from a short distance, maybe not.
When it's beamed widely in your general direction from a larger distance, you'll be fine.
At those distances, yes. I’ve gone through the certification process for even higher power units. IIRC you needed direct exposure of several minutes at much less than 1meter from the source to even begin to have risk.
This has big https://knowyourmeme.com/memes/how-do-i-shot-web energy
Those wristbands are a great example of manufacturing non recyclable garbage.
I understand that some fans might still want some souvenier, but this particular thing is an example of unecological waste.
They have this sustainability part on their website: https://pixmob.com/sustainability
It does look like they have boxes for you to return it at the end of the show. It doesn't seem too bad when I take it at face value. I'm sure the reality of how sustainable it is is a bit more complex.
It's obviously not sustainable on any level, it's a device produced for effects. Concerts in general aren't sustainable. Most of the things we do aren't sustainable.
It's nice that they collect them after shows, but still shouldn't call this product sustainable.
I disagree. I expect industrial civilization will continue indefinitely, meaning, we will continue manufacturing cute special-effect gizmos, and having fancy concerts with millions of dollars in special-purpose manufactured goods, and people will continue to have fun.
That's what sustainable means.
That's what sustainable means.
That's not how words work. You can't just make up their meaning like this.
sustainable
adjective
1. able to be maintained at a certain rate or level.
It is quite literally what sustainable means. Maybe don’t go around correcting people on the meaning of words if you haven’t bothered checking a dictionary?
Not sure if you are in bad faith or genuinely don't know how words work. Here is some help:
1. Go back to the parent, and understand the context in which "sustainable" is used here.
2. Convince yourself that the discussion is about "sustainable development": https://en.wikipedia.org/wiki/Sustainable_development
Edit: I am concerned that you may not find the origin of the thread, so let me copy it here for you:
Those wristbands are a great example of manufacturing non recyclable garbage.
They're non recyclable, but they seem very repairable and reusable? As long as people return them after the show the actual waste and churn is lower than something like plastic packaging, and might beat similar concert light sticks that don't have a removable battery. At minimum can't the batteries from these be taken out for recycling?
I was answering to the comment that said:
I disagree. I expect industrial civilization will continue indefinitely, meaning, we will continue manufacturing cute special-effect gizmos, and having fancy concerts with millions of dollars in special-purpose manufactured goods, and people will continue to have fun. > > That's what sustainable means.
But yes, I agree that it's better if they are actually repaired and reused. But being repairable and reusable is not enough: recycling, in general, doesn't really do what people expect (which is something like "it does no harm because it was recycled"). It's actually surprisingly hard to meaningfully recycle anything at all.
In this case, if it's more profitable to get new ones every time, that's probably the only incentive they need to not repair and reuse any of those.
That's what sustainable means.
No. No it is not.
It does look like they have boxes for you to return it at the end of the show. It doesn't seem too bad when I take it at face value. I'm sure the reality of how sustainable it is is a bit more complex.
They do - and at the Coldplay concert I went to, they tried to gamify it a bit by ranking cities by their return rates. Cardiff was unfortunately not at the top, though I did return mine!
Except that they aren't because they are literally collected at the end of the show and they can easily be opened and the batteries replaced. So they can be used from show to show.
Hopefully they're cleaned somehow...?
Have the same thought
The device is attached to a fabric wristband. The device is reusable, but the wristband is disposable, and can be branded for different events.
Them being collected does not mean that they are reused. But hopefully they are, because they make a lot of them.
The thing is: if it's more profitable to make new ones than to reuse the old ones, they most certainly will go that way.
They are not collected. Fans can keep them.
Maybe in some cities they were collected? Not in mine.
Are they being reused? Otherwise it's like 3D glasses that in many locations are just thrown into recycling.
Edit: From their sustainability page it seems like they're actually "refurbished" and reused. :+1:
Since these wristbands are designed for reuse they are easily opened revealing two batteries and a lovely little circuit board.
The only part that has a shorter shelf life than the rest is the fabric part of the wristband which may later be swapped out to serve another show.
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.
Can they apply an electric shock to the user if they do something Disney doesn't like?
Apparently punching Mickey doesn't count [1].
[1] https://insidethemagic.net/2023/03/world-renowned-tiktoker-d...
I want the old internet back, not whatever this is supposed to be.
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.
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.
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.
What happens after the vacation, do they reuse them or do they go in the trash?
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
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.
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 MontréalThree cheers for the date format.
What’s so special about February 20, 2030 (6:29am)?
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.
Give that comment another read ;)
Touché. I suppose the separators are important also.
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?
Provided we still have search engines that can search for literal text a few years from now, I think it should work.
Surprisingly, yes. SEO blogspam rarely optimizes for details this specific, unless it's mainstream technology (like, idk. version numbers on Windows or iPhones).
Done
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.
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!
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.
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?
Hi, I also had this idea circa 2014. I realized it wouldn't work accurately enough given the GPS limitations (and my limitations as a programmer) at the time. I pivoted to encoding color instructions in a high-frequency range of an audio signal emitted through the audio system of the stadium. I had a prototype working, but it was inconsistent and did not warrant a contract with the client. I've had the itch to complete this app since then.
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.
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.
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.
The 1st thing i thought when I opened the article: "what a useless mass production of garbage"
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!
Yesssssss! Good times and sleepless nights :) Hi Noah <3
> 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.
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.
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.
Who is this Taylor Swift Person?
Creator of a fairly popular programming language
And of a fairly popular math series
A faster version of a polynomial used for cryptography.
The lead architect of the SWIFT payments system.
She's a crooner.
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.
Pretty sure they have specific collection bins. Many keep them as a memento of the experience though.
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.
Turns out it’s the same company that makes the wristbands for the Coldplay shows, so chances are it’s the exact same here
Now you've done it. Worldwide Flipper ban incoming over this. </sarc>
I had a similar thought, given recent news around negligent automaker security and scapegoating.
For people who don't want the Flipper Zero banned... I suspect it might be smart to leave the name of the tool out of headlines.
And when we do mention what tool we used in body of the article, that same sentence, or one next to it, should be clear that we're using such-and-such standard technology (e.g., RF or IR), and that the Flipper Zero is only one of many options for doing that.
Promoting a particular product in headlines can be nice, but counterproductive if that same visibility is getting the product banned entirely.
Can be used with cars and wristbands? Won't anybody think of the children?
I wonder how many locations they can encode for? They must know where each IR device is located based on seat assignments. It's as if they're sending UDP packets out and each receiver must listen to all messages and know which light sequence to run.
They're using the directionality of the IR transmitter for "addressing", so to light up an area they just point the transmitter towards it and broadcast a command that all the receivers run. Quite an elegant method, in my opinion.
It seems like the RF model has more granular targeting than the IR model. The IR can work by focusing a narrow IR beam on the crowd... the RF model appears to be able to address groups of tags based on their pre-programmed location. In the video they show the tags already placed on the seats. So presumably they've laid them out based on these groups.
Since they are projecting infrared with moveable projector they can sweep effects around the stadium, and cover the projector with cut outs to make things like hearts.
That is wild! I had assumed this was controlled by some sort of wireless communications signal.
Well it is a (unidirectional) wireless communication signal.
Big Clive did analyse a similar Pixmob wristband here:
I'm surprised we don't see more of Big Clive on HN
Oh yeah, Infrared Radiation right to your audience eyes
Wondering why I have to double check to not get my retinas fried in the lab, but it's safe in a concert
They just need to get the equivalent amount of light into each sensor as your TV remote gets into your TV.
I doubt it would get unsafe before rising the power by many orders of magnitude... Especially considering unshielded kW IR lamps are used everywhere for heating.
In the video, the CEO of Pixmob seems like a nice, humble guy: “the wristbands are really stupid, but we like it that way.”
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.
Interesting, I had no idea these are a thing. It's been a very long time since I've last been to a large concert.
I was at a Cavs playoff game and they had these as well. I would guess they will become more popular. I've seen at some games, I think a Browns regular season game, you had to download an app and then give them access to your flashlight which I was not interested in. So this is a nice alternative to create the desired atmosphere without gaining access to users phones
Disney patented a very similar system in 2002 (it may be expired now). These were the "Magical Moments" pins, hats, wands, etc, that were sold in the parks. Controlled by IR transmitters.
(I worked on this project and still have the transmitters in my office)
That’s interesting, I’ve never noticed them used. Do they still do this? I’m aware of the bands but I never noticed the magic moments stuff.
Do people really think this is that ingenious of a solution? It seems obvious. Most likely many people here simply don’t have the domain expertise in that tech.
Do you have said domain expertise? Of course it would seem obvious if you did.
Personally I'm less familiar with IR technologies than RF, so I was expecting some radio-controlled design inside (with an overpowered IC). What they actually did seemed to me like one of those beautifully simple solutions which opened my mind a little. Sometimes simplicity is the most ingenious.
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.
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.
I would love to see a reverse engineering approach of the original mcu firmware. So far everything I found seems to cover the IR protocol only. The MCU seems to be unlabeled (https://github.com/sueppchen/PixMob_waveband/wiki/MCU )
Pretty neat how those work but those Korean ones look way better.
It would be interesting to see if someone can carry their own IR lamp and display arbitrary letters. Especially in a Taylor Swift concert..hmmm.
Is there anything similar that can be bought as a consumer, for example the Bluetooth one that they mention in the video ? This gave me a few ideas that could be fun at the kid's parties.
Seems something not hard to do with wireless-enabled microcontroller and leds, but I don't trust myself to do something safe in the hands of a kid.
Isn't it kinda dangerous to light up the audience with high power IR light? It could cause real eye damage.
Very cool! I’ve been to a few shows with these and was pretty enthralled with the level of effects that are possible given the Simplicity of the setup. I brought one wristband home hoping to mess with it but never got around to it.
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...
The most surprising IR controlled device I've seen lately is a butt plug.
Avoiding FCC testing for the win.
The video lists 3 different technologies for this kind of lighting control; RF, IR, and Bluetooth. The last one used in K-pop shows for very detailed effects. Those require the audience to buy a $100 souvenir light, and connect it to an app on their phone. What a data capture system!
Huh, neat!
They used these at Loveloud last year, and I've been wondering how they worked. I've still got mine, just one more reason to get a Flipper Zero I suppose!
A friend and I built a proof of concept of a similar thing. We could do almost per pixel playback of video on the audience without the K-pop Bluetooth style setup or assigned seats. We used computer vision and infrared beacons and timing groups to expand out to tens of thousands of them.
Thank you for the nerd-snipe, but thank goodness others had done the reverse engineering otherwise this would have been a long night...
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.
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.
Note how the worst scenario you could think of was "get stuck flashing rapidly". That's why there's no encryption.
I suppose you could (partially) ruin a concert if you infected all (or most) of the wristbands with your random blinking virus. But hitting so many would be hard, and for what gain?
Seems more like the sort of thing someone at 4chan or similar would do, just because they could. For shits and giggles.
But how is a random 4chaner getting a bluetooth signal close enough to all parts of the stadium without being noticed?
It's infrared, not bluetooth.
I'm pretty sure it has both infrared and Bluetooth.
But if it really is only IR, then this is doubly pointless because I'd like to see someone come to the stadium with a massive IR spotlight that no one noticed.
And, it's presumably only an IR receiver so how would encryption even work?
You definitely could have an encryption protocol that works on a unidirectional 38kHz IR system. You put your public key in the receiver, then you, the sender, can sign a message with the matching private key and the receiver can verify the match. You can't authenticate that only authorised devices receive the message (which is usually what the secure crypto chips with a private key in them bring to the party). You also don't need to provide any kind of secrecy - the message content is about to be broadcast in thousands of LEDs. But then you've made it much less reliable as you have to get a lot of bits across in perfect order, and adding enough forward error correction to compensate affects throughput.
Plus if you or the venue staff fluff the crypto it's another failure mode that results in Taylor Swift's legal team uncapping their Mont Blancs.
Whereas the real beauty of this system is that it leans into the noisy channel and is designed so dropping a few bits here and there is basically imperceptible. Anyone in a position to mount a malicious IR transmitter that can overwhelm the existing ones (assuming that even works and doesn't just mutually interfere and break everything) is presumably already an insider and can probably just copy "naked_hitler_flipping_the_bird.mkv" to the Jumbotron controller anyway.
But isn't this trivially susceptible to a relay attack? Anyone could capture the IR sequences that cause the band to light up in each color, and rebroadcast them whenever they want.
But I think we're in agreement that this is pointless anyway...
They certainly could do that, but:
1. Most people at this sort of concert want things like this to work. I don't think there are many people who are going to buy a ticket to go just to screw with the LED wristbands. Then again, who knows, some people are unfathomably stupid.
2. It would be fairly difficult to sneak a 30W IR lamp into the concert undetected. I suppose you could do something (much) smaller and low power; maybe disguise it as a phone or a point-and-shoot camera (which concert security may or may not allow), but then you're not going to affect all that many devices. And it also might not be hard for security to find you if they can see some sort of radius of effect from where you're standing. You'd probably have to hold it up in the air, continuously, for a while.
Right, which is why I've been saying there's no point encrypting any of this!
Add a monotonic counter/nonce
Agreed.
Bluetooth range is only limited if you care about transmission power regulations.
If you don't care about transmission power regulations you could also just jam the sound system, to heck with the pretty lights.
And then you'll get arrested.
Every large scale production event relies heavily on standard wireless microphones, which would be fairly trivial to disrupt from the parking lot.
Are digital spread-spectrum microphones used? Traditional "just modulate the mic to 485.250 MHz" systems seem too jammable/hijack-able nowadays, while a digital frequency-hopping scheme is more resistant to interference, intentional or accidental, at the expense of some milliseconds of latency.
Just looking at the most expensive wireless solution on the Shure website: Shure AD4Q Four-channel Axient Digital Wireless Receiver: 4-channel Digital Wireless Receiver with 184MHz Tuning Range, Frequency Diversity, and 256-bit Encryption, $7500.
If a large production ever has an issue with someone in the parking lot (or elsewhere) trying to jam them, the cost of one of these systems feels like basically nothing. You'll spend more on renting chairs.
As someone who produces large scale events in major cities I can tell you it's still not a solved problem. In places like Times Square there's just so much RF going on from similar devices that you can see bizarre intermittent problems. That's the observation I'm using to assume it could also be done intentionally.
Which, of course, would be a massive problem with the FCC and a felony and all that. But technically it's still possible I'm assuming.
To answer your question yes, for sure large scale productions have the top end devices, and plenty of backups.
Inside person or from above or from below
This is a really lame James Bond movie!
I recognize that it is technically possible to cause mischief with these things, but they require access to substantial resources and are likely to get you arrested, all in the pursuit of basically nothing.
That’s literally a common troll MO. People often do things despite no logical or rational reason.
I’m reminded of a quote from Edmund Hillary after successfully climbing Mt Everest (he and Tenzing Norgay being the first humans to do so). A reporter asked him why he climbed it. His response:
Because it was there.
You could definitely ruin a concert by projecting offensive symbols or messages. Especially since if it's done well, most concertgoers would initially assume that it's part of the show.
But to actually create patterns you'd need a huge IR spotlight!
Obviously you use the wristbands themselves to propagate your hacked signal.
How? They receive IR but can’t transmit it!
Even if it was possible to propagate with the bands themselve (I think the vendor’s website mentions there is a Bluetooth version, maybe you could with that), you still have the problem of not knowing where any are, so if you actually want to show anything meaningful on a group of these, you can’t really. You can just make annoying flashes.
Why huge? Something couple times stronger than a TV remote should be fine, if focused. Unless they purposefully put a powerful IR attenuator in front of the receiver, as a security measure so that a would-be attacker would really need a a "huge IR spotlight".
Because distance and reflection are the attenuators here. A stadium-sized group of kids aren't very good at pointing your receivers at your rogue transmitter.
Latency is really important for live audio at shows, so that was probably the priority.
We've found the cybersecurity enthusiast that ruins everything.
Well, it would, if you had a 30W infrared spotlight with you.
Which begs the question: how hard is it to build a 30W, portable IR spotlight that you could get through a concert’s metal detector unnoticed?
I suspect you could fit that into the form factor for a "small hand-held camera" that is apparently permitted into the tour.
It would be a fantastic form factor. After all, such a device wants a decently large battery, focusing optics, and an emitting surface at the focal plane big enough to dissipate the waste heat. This sounds a lot like a small digital camera with the sensor removed and an IR LED array put in its place.
Anyone aiming such a device across the venue would be extremely obvious, as everyone else’s inadequately filtered camera would see it :)
Right, because people looking through their cameras at all of the chaos, flashing lights and pulsating wristbands would _definitely_ notice one human being standing there with an IR transmitter and be able to understand what they were looking at.
I think at least a few photography nerds would notice the 30W white blob coming from where you're standing. Now whether that would get you in trouble...
They already have an even more powerful IR spotlight sweeping over the stadium; if that isn't ruining the photos, then I doubt the attacker's 30W source would even register.
Can confirm that everyone there is taking shitloads of photos and videos with their phones and I've never seen the stadium IR emitter appear in any of them.
The battery to run a 30W thing and the cooling required to dissipate it would look much closer to a large hand flashlight (the 3kg ones, with the handle) than a camera.
You'd need a whole row of conspirators to bring in camera-sized components that could be fit together ...
drones? that's a whole 'nother can of worms but it could work if you really .. really .. really want to be part of the light show.
Oh… drones are a really devious idea. You can imagine all sorts of political messages that someone may want to leverage an event like this to broadcast.
Flying a drone over a major concert is liable to get you charged with terrorism somehow even if you're just trying to do a prank.
Doesn't need to be big enough to scare people that badly.
You could sneak a heap of something like this into any big concert venue pretty easily:
https://www.aliexpress.com/item/1005004496779816.html
open them up and switch out the visible light LEDs for modulated IR ones, add a tiny microcontroller to send pre programmed data. Get you and a dozen friends to launch them all at the same time...
I wouldn't be surprised if concerts have anti-drone countermeasures in place already, given safety concerns.
Like what? This isn’t a battlefield, the FCC isn’t going to let them do any jamming and they sure as hell aren’t putting up CIWS cannons all over the place.
I've seen multiple NFL games be stopped in the middle because of one person flying a drone. They take this stuff extremely seriously - I wouldn't be surprised if the entire concert was put on hold until the drone was stopped. The people who have done this have served jail time and been hit with 6 figure fines.
Fwiw the show I saw was in a closed arena. I actually wish the roof had been open as the closed roof acoustics were awful, but you can imagine why they want to eliminate weather as a factor.
Go to a country where they do not use metal detectors in concerts
What about those super bright handheld LED flashlights that have the power of the sun?
I mean one of their products is a big flashlight sized control rod, so they already exist.
"Disclaimer: Use in nuclear reactors not recommended." ;)
Is 30W enough for a stadium audience?
There are a few at great locations in the stadium already.
It transmits a code, so you’d have to clone the signal but I’m pretty sure it’s not cryptographic or anything.
That was some entertainment arbitrage.
A friend told me Swift tickets + flights to PT were cheaper than local US tickets...and you get Lisbon!
Yup. My family is heading to Vienna for the same reason this summer. I wonder what fraction of attendees will be US residents?
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.