Without a transmitter, which would be fairly simple to cobble together, *and the codes to feed the wristband*, it might not light up at all. Best case it would light up the way it was last instructed to, assuming it doesn’t reset when the batteries are removed and replaced. That thought provides a fun twist on the usual IT service call dialogue: “Did you turn it off and back on again?” “Yes.” “Well, there’s your problem.”
Each unit assigned unique Address. The unit identify itself by send out high speed data through the LED. Audience-facing camera + software maps location of units in real time. Master map of units in audience like a BMP image
Thanks to Vince for letting us all have a peak at these bands. Interesting control method and band. I wonder if any went missing after a show, but not much use to anyone if you didn't know how to control it.
If you want to learn the protocol, film the control projector cans with a suitably sensitive phone (phon cameras are generally fairly sensitive to the wavelengths of IR that is used) and analyse the flashes of the IR stream. It almost certainly uses a slightly custom version of one of the many well known protocols and modulation types. Of course with a little googling, you may find that it has already been reverse engineered.
@@AndyHullMcPenguin You'd need to be recording at thousands of frames per second. An old phone with an IR blaster (like the galaxy s6, remember when smartphones came with lots of useful features?) would do the job. Or if you feel like shelling out the money for something you might only ever use for IR, a flipperzero. You could probably build your own with a pi pico as well, coin cell batteries, IR reciever and SD card inside a tiny little project box.
@@AndyHullMcPenguin Most phones (iPhones at least) have IR cut filters on the main cameras. You might have to switch to the selfie camera, which generally don't have IR filters.
The RF versions usually use 433mhz and give you a limited number of addressed units. These can be driven from Artnet. These IR units are usually all addressed the same however the IR "megga blaster" is usually fitted into moving lights! Very tight focal point on the fixture gives you control over that area of audience bands. This way you wave the light around, the patterns wave around. Interesting!
Spent a fair bit of time digging into this back in the day when I somehow got tasked with trying to replicate PixMob’s show on 1/50 the budget. Not sure what they actually implemented, but they did have a patent filed for a really simple method… just putting some sort of controllable screen in front of the IR emitter. Set it up to blanket half a stadium, then just selectively block the signal to control where it goes. If I’d had more time for my project, I really wanted to see if an LCD panel of some sort would selectively block IR depending on the colour, as that would have made a very cheap easy way to paint pictures on the stands. We ended up using RF versions, and you definitely don’t want the addresses coded on the bands if you don’t need to… it simplifies the tech, but it makes the logistics of distributing the bands _much_ harder. And anyone that sneaks up closer for a better seat can ruin the whole thing.
@@adampippin135 Exactly. I only know about the IR moving lights from another video. Looks easy enough to implement though. Once you have the IR in place in a moving light you can apparently then use the gobos and shutters in the light to effect different areas. Its a simple old skool solution to an otherwise complex problem. I guess a mixture of 8 or 10 moving lights with IR and a few Wash IR would be needed to effect the whole audience at once. Would be easy enough to setup a fixture profile for this.
I'm sure I saw way to hack these wristbands on the adafuit channels a few weeks back , where they wrote & demonstrated code to trigger the wristbands. It seems now to be missing so I presume they got asked to ask to take it down ...
I saw a video interview with a company that runs these sort of bands.. they said they use IR because they can effectively "paint" the audience with IR signals to draw pictures, rather than needing to specifically address a specific code via RF to draw pictures.. so regardless of if someone's in one section or another, they'll only get triggered by line of site IR.
@@carlubambi5541I mean, they don't. The devices have no transmit function. Being IR controlled, of course, they could use directional beams of IR to control what areas of an audience light up with what color-but that doesn't track anyone.
@@ConstantlyDamaged but you can via cameras and other light detectors .You can 3 d pin point positions of those wearing a device .It's similar to how they do 3 d graphics and augmented 3 d video animation with numerous color dots and green screen/blue screen
odd indeed...but i belive ur right bout the led's the mosfets are there to limit the maximum current (i see no other reason) .. the red leds are more stable, and more stable during various temps... there most be 3 different types of leds with very different behaviour during use, the control chip we can assume is just on/off?... and thers no circut to fade any of them... (atleast not outside of the chip, possbly the chip has some ability to control the red channel, but i doubt it, and difficult to control the green/blue as thay are connected to mosfets) ..the IR decoupling capacitor is likely a load leveling device for the IR chip..? ...what i dont get is the coupling of the mosfets in an always on state (its impossible close them) ther always current running trough the green/blue led's...
@@ConstantlyDamaged wrong .With 3 cameras you can spatially track a person quite easily .You do the same thing with dots on a body with blue /green screen .That's how many CGI movies are done .Give the receiver the specific command to turn on and off at specific intervals and /colors in specific patterns and have the cameras track the light .Easy peasy Pick your color you want to track and tell the device to turn on or off at a specific rate and you can track anything
On a similar vein, in Japan, they're big on light sticks at concerts. One show I went to, they just handed out chemical glow sticks in random colours, but at Magical Mirai they were selling battery-powered ones with RGB LEDs and a button to cycle through the different Vocaloids' associated colours.
Diode in MCU supply is so called "anti brown out" diode. When MCU switch on LEDs - voltage in system drops so much that it can lock up the processor. Diode keeps little charge in decoupling capacitors to run MCU fort short time while voltage stabilizes.
The main purpose I see for the Schottky diode is protection against batteries installed in reverse polarity. Processor and memory chips don't like that. Schottky is used to minimize the voltage drop when batteries are installed correctly. LEDs don't need to the reverse protection diode because they themselves are high impedance when reverse biased. Keeping them and their transistors directly connected to the + side of the batteries keeps the voltage drop of the Schottky diode from reducing the already low voltage margin between battery voltage and the close-to-3V forward voltage needed for blue and green LEDs. The 660 ohm resistor in series with the IR receiver's supply limits its worst case reversed battery current to 4.54 milliamps, x3 volts = less than 14 milliwatts, which is likely low enough not to damage the receiver, while the voltage drop across the resistor is only about 0.33 volts in normal (forward battery polarity) operation, allowing a receiver with minimum supply spec of 2.5 V to work okay.
The WSJ did a video on these a couple months ago "How Concert LED Wristbands Work". The CEO of Pixmob seems to have basically told them everything, the whole system for both the RF and IR controls is explained in enough detail to make scanning for the RF wavelength or imaging the Par IR launchers trivial and hacking the signal protocol likely an easy enough project for a highschool kid. Ores mined from the earth all over the world, metals refined and purified, chemical electrolytes and semiconductors fabricated and packaged, assembled by robots in a cleanroom, all so it can flash an LED to "WAP" for an hour and then be thrown into a landfill for eternity. Hooray for 'progress'. 😒
Super cool getting to see you take one of these apart. I literally have one of these taken apart on my workbench right now. I use to work for a Pixmob competitor and met them at a tradeshow a couple of times. Their whole booth is coverd in the bands, and besides the IR projectors, theres a magic wand kind of thing that selectively turns on small groups of the bands. It's like a big IR laser remote. Pretty fun to mess around with.
Fascinating! It would be interesting to know more about the 'InfraRed' PAR cans and how they send the data and how many they use and how they are rigged to cover the whole audience.
They almost look indistinguishable from a regular overseas built LED par. They have an led array in the front, a standard locking yoke and a 5-pin DMX connection in the back. You pretty much just place them like you would place any audience washers.. light is light, after all.
In late 2014, I took my wife to Disney World's Magic Kingdom. (She'd never been, and I hadn't been since the 80s.) They were selling lighted mouse ear hats which coordinated with the show. I assumed they were using some unlicensed RF spectrum, but infrared makes so much more sense (especially when it's dark out -- though maybe the modulated signal would still work with the sun up?). Now I need to smuggle an IR camera into a concert with these things to see if I can work out the signaling. 😁
@@fredfred2363 You could knock something up with an Arduino and one of the same IR receiver modules this one uses. Wouldn't have to match the particular component, they're all standard and demodulate the 40KHz or so carrier. Then just record it at however many bits per second you think would be suitable, not gonna be many since the theoretical maximum would be 20KHz, likely quite a bit less than that. Maybe use a serial EEPROM to store a bitstream, and time / date if you wanna show off, whenever you press a button. A bit like a camera in a way. Or else have it auto-trigger whenever the sensor detects a carrier, shouldn't get many false positives.
For those not familiar with these ubiquitous IR receivers there's a photodiode followed by a bandpass amplifier, centred on around 38-40kHz with AGC, a rectifier/detector and a data slicer/threshold detector. Output is usually open collector and the case has a dye that transmits near-IR. The sensitivity is quite high. Some years back we were using an undocumented feature of these to do simple person presence detection for POS displays. I cocked up a bit of AVR timer/counter programming and ended up with 4.7kHz Tx modulation IIRC. It still worked fine.
Wonder why they use P-channel switches, as N-channel tend to have lower RdsOn for a given price. Maybe the memory device holds some preprogrammed effects sequences so these can be programmed by the show designer.
Regarding the IR fixtures you mentioned for controlling these -- where I work, we used to use some of the Altman outdoor PAR 600 fixtures with IR filters in them to wash entire areas with IR for surveillance cameras. I know you can't modulate them like LEDs, but they worked great for that application, and the IR was not nearly as visible to the eye as LEDs.
The IR controlled ones typically use IR lights - typically there on a pan-tilt light head so it can sweep across the audience (there usually are several of these). I don't believe they're generally individually addressible other than controlling color - the bands respond to the IR codes if they can see the (they light up) and generally the color and location is controlled via DMX treating the splash of color not coming from the light head, but from the audience. A more sophisticated system uses RF to produce the audience "video wall" system - this relies on the fact that each audience member has a seat so their band's address is entered into the system. Throughout the concert, the RF signals will trigger the bands - I believe they're relatively short range so they can update them all frequently since they're individually addressable.
Great teardown as always. I can't get over the feeling of enormous waste that comes with trinkets like these. Are the wristbands and batteries just disposed of by patrons after the concert, or are they collected in some way?
I found one in a suburban street here in Brisbane Qld near where I live. It came with two discharged AAAA batteries which up till that point I didn't know existed.
The type that use AAAA cell are the older Xylo-Bands. No really used much anymore, Although Eurovision did use Xylo-Band this year! But most big concerts use Pixmob now, and lower budget use Cheap Chinese RF Clones.
FWIW the pinout on the MCU correlates with an 8 pin PIC12/PIC16. Pin 1 Vdd, Pin 8 Vss, and Pin 4 must always be an input (MCLR/RA3), in this case from the IR.
When I was a teenager in the 80's me and some friends used to put fishing float chemical lights into our mouths when we went to an asylum's staff club disco's. In the darkness the effect was excellent. In the darkness we used to look like fireflies scattered all over the dance floor flashing messages about the girls in morse code. Suddenly we'd see a particular pattern -... .- .-. and up to 20 of us would suddenly turn and all walk at different angles across the pitch black loud dance floor towards a set of stairs. Next stop the BAR and a round bought by one of us.
Sadly, it would require the specialist control system to make it work. If the batteries are installed it doesn't light until a control signal is received.
IIRC, in 2012, Disney's California Adventure had a nighttime show that used something like this. They sold special mouse ears that would coordinate with the show. It supposedly was controlled by IR. (It was called, "Glow with the show" if you want to look it up.) They had 2 to 3 dozen "zones" where the ears in each zone lit up to a particular color. They could even make the ears different colors.
The flexible PCB would be very cool as part of a wrist band, but why then put it in a hard plastic case. A pair of AAAs seems overkill for something that could probably be powred for one performance by a CR2032. Or were they collected and resused for each show?
The plastic difuses the led light. And button cells are just terrible, theres plenty of low capacity aaa batteries, the sort that get used for solar lights, off a full charge they last a few hours in the evening for one led to light up a bit of a garden. So they want them to be bright enough for a 2+ hour show, and not have faded out by the last song. A button cell wouldn't cut it.
At the coldplay concert they had collection bins, but weren't to bothered if you kept them. So the challenge for Clive now is to make them light up from an Ir transmitter
Excellent timing, I just saw these on a vlog and wondered how they could control so many lights in a single space seeing there seemed to be a lot of different channels to treat them like any other part of the lighting rig. Granted, no doubt they dont all work all the time, that's the benefit of everyone having one.
I was given an RF version which has 2 CR2032 lithium batteries. Sadly, I think most of these get tossed after the concert contributing to the e-waste problem.
There was a great video on TikTok of a guy who’d reverse engineered the IR based light bands at Taylor Swift concerts, and integrated it into an entire RGB led strip based jacket that worked at concerts
This might work similar to ht12e and ht12d (serial encoder / decoder), but instead of a fixed address, it's probably stored in the small memory. They might be able to program it just before the show and use each entrance to give specific bands to people. Or maybe they can program it live with a focused ir spotlight. Maybe they literally need to paint the crowd with addresses.
Alkaline AA and AAA cells seem to be getting more expensive at e.g. Dollar Tree but the carbon-zinc ones sold as “super heavy duty” less so. I think it’s purely economics leading to the choice of cells.
That circuit board got me thinking there might be a market for a bandaid (aka plaster) printed with a similar image. They do cartoony ones for children, why not make a version for geeky adults?
I was at one of the Mylo Xyloto Coldplay gigs when they first used these bands about 10 years ago (maybe more?!), it was a pretty cool effect at the time!
I dissected the one I brought home after seeing Taylor Swift in Seattle. Two 1632 coin cells, two tri-colour LEDs, 8 pin microprocessor, IR receiver, an SOT23-5 device that I can't quite make out the markings, assorted passive components. A rigid rectanguler PCB that says, among other things, VIC v2.3r1
Ours were the same ones Clive is showing for Taylor in LA, I kept all 3. Tore one down, can slightly control it with an IR remote control. We think the wristbands were different that night because they were also filming the concert. Other friends had the smaller ones like yours on other nights of the LA shows.
I believe various light up toys sold at Disney Theme Parks used similar tech; certain of those light-ups sold at the parks will change color in time to music during after-dark parades and shows.
I wonder if blasting a TV remote at it would have any effect. Probably coded to the controller, but electronics being what it it is, a lot of similar circuitry is shared over different devices and crossovers are quite common.
OK, non related comment/question. In March I bought 2 rechargeable 54-led pantry lights on Amazon. They have 3 settings; on, off and auto (motion sensing). Now they won't turn off even in the off position. They only go off when the battery discharges. The company has replaced them.
Fascinating bit of kit - I never thought about how these things worked, but I suppose any sort of two-way protocol wouldn't really be expandable to the tens of thousands of units at a big stadium gig, and radio would come with too much risk of interference with the audio, so good old-fashioned infrared probably makes the most sense. I also wonder what those big IR LED emitters look like through a digital camera - would they show up on the footage on the big screens they have at concerts? The idea of bonus lighting effects only visible in photographs and video recordings sounds like something Radiohead might come up with... This has got me thinking about other mass-audience gadgets now, next time I'm on the salvage team for a large festival, I'll have to grab a set of the "silent disco" headphones to send in, as they frequently get left behind on the campsite and I'd be interested to see one reverse-engineered.
it's probably a lot cheaper than korean concert lightsticks which almost every group has and can be synced to the concert halls equipment via radio, too
I got 3 of these from the Taylor Swift Eras Tour a few weeks ago. I have been wondering what I can do with them. So far, I was only able to get the LEDs to change slightly using IR from a remote control. I do have Arduinos and Raspberry PIs laying around and an IR blaster to mount on a breadboard. I think the problem with the IR remotes I was using is they pulse vs being continuously on.
I guessed an infrared interface would be used. Similar to those little light pods that you can drop into swimming pools, fish tanks and flower vases that are infrared remote controlled
IR controlled? That would need a strong IR Transmitter for a large crowd. Imagine removing IR filter of a camera so you can really see this IR Transmitter. BRIGHT.
Most cameras and cell phones can see IR. Aim your TV remote at your camera for a test. I used to use this to see which optical fibers were lit at work, it annoyed me that iPhones had really good IR filters and wouldn't work so I had to carry a cheap digital camera.
I've been to a few weddings, where a similar device was used to 'stimulate' the wristbands of the attendees. I believe it utilized a form of PCM to address specific groups of bands. The emitters were scattered about the reception hall. It would be interesting to experiment with these. On a slightly different, but related note. 3M has product, which they market under the name Optocom, that is sold to government entities, for the purposes of optically controlling Stop-n-Go lights, for emergency & public transportation vehicles. A modulated strobe, at a certain frequency is utilized to pre-empt a traffic intersection, for the passage of 'preferred' vehicles. Very interesting technology.
Almost certainly. Each unit is an addressable pixel in an audience-size bitmap image. What I think what's most interesting of all: is how differently to actual the Public Domain perceives these to work, and it's right here in video comments is the source of the perception!
Would have been quite neat if it had a microphone so it could react to music if an infrared signal is not present. That way the user could wear it to other parties. Multiple resistors for red being used as links is a good call. Is it a single layer PCB?
As I Know Of The Pixmob Syatem Uses Another Dmx Controller That Controlls A Set Of Moving Heads With Ir Blasters On Them, These Pass Through Encoded Codes With Color And Other Stuff So They Can Like Draw Out A Image In A Cetarn Colour By Moving The Moving Head In A Design!
Hey, I'd like to send something in for some reverse engineering (a smart LED bulb) but I can't find any info about that on your site - what's the best way to get in touch for more details?
I have a few different smart lamps here. They usually have a simple power supply, WiFi/bluetooth microcontroller and a specialist serially controlled linear current regulator chip.
@@bigclivedotcom I tried leaving a comment explaining what it is (teckin smart bulb with a broken screw base that I'd like to see if I can power off USB PD at 20V or something similar) but the comment didn't go through (or was automatically removed), oops!
Clive, do you want the latest model from the Music of the Spheres tour to compare? What i dont understand is how the make perfect hearts and stars in the audience? Are they shining IR beams in figures at the audience or how do they do it?
They use the equivalent of a huge tv image projector, except instead of light, it's IR. And instead of varying light brightness, it's high speed data packets. So as the "tv lines" scan (light up) the audience, all the IR receivers pick up what ever data light pattern they need (individually) to show. Sounds complex, but actually quite simple.
I'm really surprised I haven't seen these in any japanese band performances, they love their glowsticks but afaik they are still being controlled by the audience by pushing a button. An infrared system would make much more sense in this case, I think.
You might be able to trigger this in random ways with some standard IR remotes for TV's. etc. At least you should be able to get some sort of output...maybe a follow-up video or short trying my idea?
Id imagine theres also arduino code out there to do universal remote programming. Though id imagine it wouldbe a lot easier for someone to go to an event that uses these with a ir reciever and try to intercept all the codes being used.
Clive. I was watching the tattoo highlights tonight and saw the 40 (ish) ladies doing Scottish dancing. When they first came out they were wearing blue dresses but near the end the dresses turned to pink or red. Were they just wearing white and the lights changed colour or was it a bit more interesting. 🤔 Im only asking because their skin tones didn't appear to change much or the cameras recording the event did what cameras do and adapt. Also. Hello Vince. 👋😀
The dresses are two layer with neodymium magnets to hold them in place. At a key point, the dancers reach up and pull a tab and the blue layer drops down to reveal the pink layer.
@@bigclivedotcom Thank you Clive, that I missed. Maybe they had been practicing? 😆 Hopefully one year I'll make it up there. I've done stage work but not to the standard that you all work to, so I won't be able to be backstage. 😀 I'll have to sit in the crowd! 😳 Now I'm going to look at them again. 😀👍
The 7 basic colors (and off) from an RGB led could be expressed in three binary digits (000-111). The remote might be working just because those bits show up coincidentally in its commands.
i do wonder if its possible to use those circuits and your own infrared light along with a bit of wires connected to some other stuff to use it as a remote control
thanks for the great video as usual. you know what would be fun? if you made a secondary channel with the "uncut RE process". I'm curious how you approach reversing somehting like this.
So theyd use them for maybe a group of shows that are each separate pay amounts so the people who didnt pay for certain shows the wrist band would light up red notifying they didnt to the security? Or just to make everybody glow certain colors during shows?
I have some Xylobands which I bought to repurpose to use as bands at my wedding reception, but went for some off-the-shelf chinese ones instead (time was of the essence and reverse engineering the code to drive the xylobands was taking too long). Would be happy to send one of each to you for a future video?
@@bigclivedotcom They're both controllable - the ones I bought came with a DMX-controllable radio transmitter. Not sure about the xylobands, but I believe they are also radio controlled - there was a project to build a transmitter but I didn't get as far as making it as some of the components for it were still on long backorder when I looked at it.
I feel a bit like the proper scientists who didn't invent the infinite improbability drive. I never get invited to those sorts of concerts. I imagine the IR environmental projector driven ones make for a memorable show.
It is a switch controlled by a voltage. The voltage from the microcontroller is a low power signal. The mosfet switched the current to the LED, which is a high current. Like a transistor or a relay, but not draining any current to open or close the switch.
I've seen little light batons synced. Kinda wank to remove real interaction for something that looks better on camera. It was a Miku live show recorded I saw them on.
Do these things often use IR or have they been seen to use radio signals too? I have two from some concerts but I don't really want to open them up since they are elaborate and collectibles, I assumed they were radio controlled since they are single colour and all came on and off at the same time.
(2×) AAA cells, 3 volts. This must have been from far enough back that 100-200mah Lipo cells weren't cheap enough yet. I would think today that these things would all have a small Lipo in them, and they'd probably work better, and be brighter, with the extra volt of headroom that the Lipo gives.
Clive, why no demonstration of how they work? Could’ve even shown off a few dance moves.
Without a transmitter, which would be fairly simple to cobble together, *and the codes to feed the wristband*, it might not light up at all. Best case it would light up the way it was last instructed to, assuming it doesn’t reset when the batteries are removed and replaced.
That thought provides a fun twist on the usual IT service call dialogue:
“Did you turn it off and back on again?”
“Yes.”
“Well, there’s your problem.”
Each unit assigned unique Address.
The unit identify itself by send out high speed data through the LED.
Audience-facing camera + software maps location of units in real time.
Master map of units in audience like a BMP image
Well, he *did* mention that he didn't have AAA batteries with him...
Read the description
Now I want to see Clive raving under a strobe light!
Thanks to Vince for letting us all have a peak at these bands. Interesting control method and band. I wonder if any went missing after a show, but not much use to anyone if you didn't know how to control it.
Id imagine most people kept them.
They probably pay enough for their ticket, people keep them as a keepsake. Or they just forget to take them off.
If you want to learn the protocol, film the control projector cans with a suitably sensitive phone (phon cameras are generally fairly sensitive to the wavelengths of IR that is used) and analyse the flashes of the IR stream. It almost certainly uses a slightly custom version of one of the many well known protocols and modulation types. Of course with a little googling, you may find that it has already been reverse engineered.
@@AndyHullMcPenguin You'd need to be recording at thousands of frames per second.
An old phone with an IR blaster (like the galaxy s6, remember when smartphones came with lots of useful features?) would do the job.
Or if you feel like shelling out the money for something you might only ever use for IR, a flipperzero.
You could probably build your own with a pi pico as well, coin cell batteries, IR reciever and SD card inside a tiny little project box.
@@AndyHullMcPenguin Most phones (iPhones at least) have IR cut filters on the main cameras. You might have to switch to the selfie camera, which generally don't have IR filters.
They gave them out at Glastonbury for Coldplay, obviously no way to get them back there.
The RF versions usually use 433mhz and give you a limited number of addressed units. These can be driven from Artnet. These IR units are usually all addressed the same however the IR "megga blaster" is usually fitted into moving lights! Very tight focal point on the fixture gives you control over that area of audience bands. This way you wave the light around, the patterns wave around. Interesting!
Spent a fair bit of time digging into this back in the day when I somehow got tasked with trying to replicate PixMob’s show on 1/50 the budget.
Not sure what they actually implemented, but they did have a patent filed for a really simple method… just putting some sort of controllable screen in front of the IR emitter.
Set it up to blanket half a stadium, then just selectively block the signal to control where it goes.
If I’d had more time for my project, I really wanted to see if an LCD panel of some sort would selectively block IR depending on the colour, as that would have made a very cheap easy way to paint pictures on the stands.
We ended up using RF versions, and you definitely don’t want the addresses coded on the bands if you don’t need to… it simplifies the tech, but it makes the logistics of distributing the bands _much_ harder. And anyone that sneaks up closer for a better seat can ruin the whole thing.
@@adampippin135 Exactly. I only know about the IR moving lights from another video. Looks easy enough to implement though. Once you have the IR in place in a moving light you can apparently then use the gobos and shutters in the light to effect different areas. Its a simple old skool solution to an otherwise complex problem. I guess a mixture of 8 or 10 moving lights with IR and a few Wash IR would be needed to effect the whole audience at once. Would be easy enough to setup a fixture profile for this.
They also use moving lights refitted with IR lamps and that way they can use the Gobos to have patterns like hearts moving around the audience.
I'm sure I saw way to hack these wristbands on the adafuit channels a few weeks back , where they wrote & demonstrated code to trigger the wristbands. It seems now to be missing so I presume they got asked to ask to take it down ...
I‘ve experienced a Coldplay concert yesterday. These wristbands and the atmospheres they create are pure magic
I saw a video interview with a company that runs these sort of bands.. they said they use IR because they can effectively "paint" the audience with IR signals to draw pictures, rather than needing to specifically address a specific code via RF to draw pictures.. so regardless of if someone's in one section or another, they'll only get triggered by line of site IR.
I'd imagine the resistor values for the LEDs were also chosen to balance the color intensity.
In all, a very neat little circuit.
Awesome device that can be used for other nefarious purposes .I wonder how the monitored people movements in the crowd ????
@@carlubambi5541I mean, they don't. The devices have no transmit function.
Being IR controlled, of course, they could use directional beams of IR to control what areas of an audience light up with what color-but that doesn't track anyone.
@@ConstantlyDamaged but you can via cameras and other light detectors .You can 3 d pin point positions of those wearing a device .It's similar to how they do 3 d graphics and augmented 3 d video animation with numerous color dots and green screen/blue screen
odd indeed...but i belive ur right bout the led's the mosfets are there to limit the maximum current (i see no other reason) .. the red leds are more stable, and more stable during various temps... there most be 3 different types of leds with very different behaviour during use, the control chip we can assume is just on/off?... and thers no circut to fade any of them... (atleast not outside of the chip, possbly the chip has some ability to control the red channel, but i doubt it, and difficult to control the green/blue as thay are connected to mosfets)
..the IR decoupling capacitor is likely a load leveling device for the IR chip..?
...what i dont get is the coupling of the mosfets in an always on state (its impossible close them) ther always current running trough the green/blue led's...
@@ConstantlyDamaged wrong .With 3 cameras you can spatially track a person quite easily .You do the same thing with dots on a body with blue /green screen .That's how many CGI movies are done .Give the receiver the specific command to turn on and off at specific intervals and /colors in specific patterns and have the cameras track the light .Easy peasy Pick your color you want to track and tell the device to turn on or off at a specific rate and you can track anything
On a similar vein, in Japan, they're big on light sticks at concerts. One show I went to, they just handed out chemical glow sticks in random colours, but at Magical Mirai they were selling battery-powered ones with RGB LEDs and a button to cycle through the different Vocaloids' associated colours.
Diode in MCU supply is so called "anti brown out" diode. When MCU switch on LEDs - voltage in system drops so much that it can lock up the processor. Diode keeps little charge in decoupling capacitors to run MCU fort short time while voltage stabilizes.
The main purpose I see for the Schottky diode is protection against batteries installed in reverse polarity. Processor and memory chips don't like that. Schottky is used to minimize the voltage drop when batteries are installed correctly. LEDs don't need to the reverse protection diode because they themselves are high impedance when reverse biased. Keeping them and their transistors directly connected to the + side of the batteries keeps the voltage drop of the Schottky diode from reducing the already low voltage margin between battery voltage and the close-to-3V forward voltage needed for blue and green LEDs. The 660 ohm resistor in series with the IR receiver's supply limits its worst case reversed battery current to 4.54 milliamps, x3 volts = less than 14 milliwatts, which is likely low enough not to damage the receiver, while the voltage drop across the resistor is only about 0.33 volts in normal (forward battery polarity) operation, allowing a receiver with minimum supply spec of 2.5 V to work okay.
The WSJ did a video on these a couple months ago "How Concert LED Wristbands Work". The CEO of Pixmob seems to have basically told them everything, the whole system for both the RF and IR controls is explained in enough detail to make scanning for the RF wavelength or imaging the Par IR launchers trivial and hacking the signal protocol likely an easy enough project for a highschool kid. Ores mined from the earth all over the world, metals refined and purified, chemical electrolytes and semiconductors fabricated and packaged, assembled by robots in a cleanroom, all so it can flash an LED to "WAP" for an hour and then be thrown into a landfill for eternity. Hooray for 'progress'. 😒
Super cool getting to see you take one of these apart. I literally have one of these taken apart on my workbench right now. I use to work for a Pixmob competitor and met them at a tradeshow a couple of times. Their whole booth is coverd in the bands, and besides the IR projectors, theres a magic wand kind of thing that selectively turns on small groups of the bands. It's like a big IR laser remote. Pretty fun to mess around with.
Fascinating! It would be interesting to know more about the 'InfraRed' PAR cans and how they send the data and how many they use and how they are rigged to cover the whole audience.
They almost look indistinguishable from a regular overseas built LED par. They have an led array in the front, a standard locking yoke and a 5-pin DMX connection in the back. You pretty much just place them like you would place any audience washers.. light is light, after all.
In late 2014, I took my wife to Disney World's Magic Kingdom. (She'd never been, and I hadn't been since the 80s.) They were selling lighted mouse ear hats which coordinated with the show. I assumed they were using some unlicensed RF spectrum, but infrared makes so much more sense (especially when it's dark out -- though maybe the modulated signal would still work with the sun up?). Now I need to smuggle an IR camera into a concert with these things to see if I can work out the signaling. 😁
most of them are using radio, only these new ones use IR. see the WSJ video done on them a couple months ago "How Concert LED Wristbands Work "
It'd have to be a high speed camera, if the data burst is in the kHz region.
a normal phone camera would probably see the IR
ruclips.net/video/GCsmZA08oD8/видео.html&ab_channel=WallStreetJournal
@@fredfred2363 You could knock something up with an Arduino and one of the same IR receiver modules this one uses. Wouldn't have to match the particular component, they're all standard and demodulate the 40KHz or so carrier. Then just record it at however many bits per second you think would be suitable, not gonna be many since the theoretical maximum would be 20KHz, likely quite a bit less than that. Maybe use a serial EEPROM to store a bitstream, and time / date if you wanna show off, whenever you press a button. A bit like a camera in a way. Or else have it auto-trigger whenever the sensor detects a carrier, shouldn't get many false positives.
For those not familiar with these ubiquitous IR receivers there's a photodiode followed by a bandpass amplifier, centred on around 38-40kHz with AGC, a rectifier/detector and a data slicer/threshold detector. Output is usually open collector and the case has a dye that transmits near-IR.
The sensitivity is quite high. Some years back we were using an undocumented feature of these to do simple person presence detection for POS displays. I cocked up a bit of AVR timer/counter programming and ended up with 4.7kHz Tx modulation IIRC. It still worked fine.
Wonder why they use P-channel switches, as N-channel tend to have lower RdsOn for a given price. Maybe the memory device holds some preprogrammed effects sequences so these can be programmed by the show designer.
It does seem a bit odd.
Regarding the IR fixtures you mentioned for controlling these -- where I work, we used to use some of the Altman outdoor PAR 600 fixtures with IR filters in them to wash entire areas with IR for surveillance cameras. I know you can't modulate them like LEDs, but they worked great for that application, and the IR was not nearly as visible to the eye as LEDs.
It's 4am, I can't sleep and Big Clive has a new video....yes please.
Very interesting story there, thanks for sharing.
I did some digging and see they have rf ones as well, it's neat.
RF version's video is made and coming soon.
The IR controlled ones typically use IR lights - typically there on a pan-tilt light head so it can sweep across the audience (there usually are several of these). I don't believe they're generally individually addressible other than controlling color - the bands respond to the IR codes if they can see the (they light up) and generally the color and location is controlled via DMX treating the splash of color not coming from the light head, but from the audience. A more sophisticated system uses RF to produce the audience "video wall" system - this relies on the fact that each audience member has a seat so their band's address is entered into the system. Throughout the concert, the RF signals will trigger the bands - I believe they're relatively short range so they can update them all frequently since they're individually addressable.
RF version's video just released.
Clive top content.
It's just amazing how the programming within components makes the final product so straight forward to make and operate.
Always providing teardowns I never knew I wanted
I went to a Coldplay concert with something similar and it was an amazing show!
Very cool 😎
Awesomeness and Thanks 😊 Vince the Crew Chief for donating it to us BigClive 🥰
Great teardown as always.
I can't get over the feeling of enormous waste that comes with trinkets like these. Are the wristbands and batteries just disposed of by patrons after the concert, or are they collected in some way?
They had bins for recycling them on the way out of the show.
I found one in a suburban street here in Brisbane Qld near where I live. It came with two discharged AAAA batteries which up till that point I didn't know existed.
@@SubTroppo AAAA batteries are used in some active styluses for tablet computers. AAAA batteries are also used inside some brands of PP3 9V batteries.
@@DavidWood2 Thanks. After my "discovery" I did keep my eye out for them on sale and found them "at a price" in an Office Works store.
The type that use AAAA cell are the older Xylo-Bands. No really used much anymore, Although Eurovision did use Xylo-Band this year! But most big concerts use Pixmob now, and lower budget use Cheap Chinese RF Clones.
FWIW the pinout on the MCU correlates with an 8 pin PIC12/PIC16. Pin 1 Vdd, Pin 8 Vss, and Pin 4 must always be an input (MCLR/RA3), in this case from the IR.
When I was a teenager in the 80's me and some friends used to put fishing float chemical lights into our mouths when we went to an asylum's staff club disco's. In the darkness the effect was excellent. In the darkness we used to look like fireflies scattered all over the dance floor flashing messages about the girls in morse code. Suddenly we'd see a particular pattern -... .- .-. and up to 20 of us would suddenly turn and all walk at different angles across the pitch black loud dance floor towards a set of stairs. Next stop the BAR and a round bought by one of us.
This is the first time I see a review of a product that doesn't show how the damn thing actually works. Genius!!!
Sadly, it would require the specialist control system to make it work. If the batteries are installed it doesn't light until a control signal is received.
@@bigclivedotcom Ha! I found at least 2 videos that illustrate how to re-activate the wristband. At home!
That's nice! I really want to see the infered projection - activated setup - and props to the makers for making it that way!
It might be nice to capture the IR signal with a Flipper Zero or similar device and then rebroadcast to the one band.
Maybe next year.
I think that's already been done.
IIRC, in 2012, Disney's California Adventure had a nighttime show that used something like this. They sold special mouse ears that would coordinate with the show. It supposedly was controlled by IR. (It was called, "Glow with the show" if you want to look it up.)
They had 2 to 3 dozen "zones" where the ears in each zone lit up to a particular color. They could even make the ears different colors.
Well, this is new to me, never heard of such a thing. In my day it was just lighters. I'll have to check these out.
Very interesting party trick for the audience. Well done.
The flexible PCB would be very cool as part of a wrist band, but why then put it in a hard plastic case. A pair of AAAs seems overkill for something that could probably be powred for one performance by a CR2032. Or were they collected and resused for each show?
The plastic difuses the led light.
And button cells are just terrible, theres plenty of low capacity aaa batteries, the sort that get used for solar lights, off a full charge they last a few hours in the evening for one led to light up a bit of a garden. So they want them to be bright enough for a 2+ hour show, and not have faded out by the last song. A button cell wouldn't cut it.
At the coldplay concert they had collection bins, but weren't to bothered if you kept them. So the challenge for Clive now is to make them light up from an Ir transmitter
2032's and other button cells are higher regulated because kids swallowing them.
Maybe why AAA used
I'm not sure a 2032 could drive 3 LEDs brightly for the length of a concert. They have quite high internal series resistance compared to 2* AAAs
Not enough energy in lithium coin cell. The unit has to be continously listening and identify itself when polled
Coldplay last concert used the same wrist bands, I was interested to know how they worked and now I do, thanks
Ive never heard of that. Weird.
Next thing we Know people will be Trolling concerts with remote controls.
Excellent timing, I just saw these on a vlog and wondered how they could control so many lights in a single space seeing there seemed to be a lot of different channels to treat them like any other part of the lighting rig. Granted, no doubt they dont all work all the time, that's the benefit of everyone having one.
Each unit has a unique address. When polled it shouts "that's me" response through its LED
I was given an RF version which has 2 CR2032 lithium batteries. Sadly, I think most of these get tossed after the concert contributing to the e-waste problem.
They are of course collected and reused at the next concert on the tour.
@@magnushacker5203 Sometimes.
There was a great video on TikTok of a guy who’d reverse engineered the IR based light bands at Taylor Swift concerts, and integrated it into an entire RGB led strip based jacket that worked at concerts
You could use a single receiver to control a whole outfit. Possibly with just three MOSFETs.
Still have a couple of CP MX from 2012. Always wondered how they worked. Thanks 👌🏻
This might work similar to ht12e and ht12d (serial encoder / decoder), but instead of a fixed address, it's probably stored in the small memory. They might be able to program it just before the show and use each entrance to give specific bands to people. Or maybe they can program it live with a focused ir spotlight. Maybe they literally need to paint the crowd with addresses.
Fascinating piece, a shame that AAA batteries were old and leaky, a bit like me really 😂. Thanks for the post. 👍
Alkaline AA and AAA cells seem to be getting more expensive at e.g. Dollar Tree but the carbon-zinc ones sold as “super heavy duty” less so. I think it’s purely economics leading to the choice of cells.
Presumably, without elecronic enhancement, the trite kiddie-pop isn't enough to retain the attention of the audience.
Definitely something that would go down well on the Golgafrincham B Ark I feel….
That circuit board got me thinking there might be a market for a bandaid (aka plaster) printed with a similar image. They do cartoony ones for children, why not make a version for geeky adults?
I would think the solder, being a toxic substance, is not something you'd want in contact with open wounds. Not to mention the batteries.
@@mxslick50no gain without pain
@@mxslick50you could just use lead-free solder
anyway I'm pretty sure the original commenter meant exactly that, a printed image, not an actual circuit board
I was at one of the Mylo Xyloto Coldplay gigs when they first used these bands about 10 years ago (maybe more?!), it was a pretty cool effect at the time!
Lightstick versions of this exist as well. Pretty cool effects.
I dissected the one I brought home after seeing Taylor Swift in Seattle. Two 1632 coin cells, two tri-colour LEDs, 8 pin microprocessor, IR receiver, an SOT23-5 device that I can't quite make out the markings, assorted passive components. A rigid rectanguler PCB that says, among other things, VIC v2.3r1
Ours were the same ones Clive is showing for Taylor in LA, I kept all 3. Tore one down, can slightly control it with an IR remote control. We think the wristbands were different that night because they were also filming the concert. Other friends had the smaller ones like yours on other nights of the LA shows.
I believe various light up toys sold at Disney Theme Parks used similar tech; certain of those light-ups sold at the parks will change color in time to music during after-dark parades and shows.
I wonder if blasting a TV remote at it would have any effect. Probably coded to the controller, but electronics being what it it is, a lot of similar circuitry is shared over different devices and crossovers are quite common.
OK, non related comment/question. In March I bought 2 rechargeable 54-led pantry lights on Amazon. They have 3 settings; on, off and auto (motion sensing). Now they won't turn off even in the off position. They only go off when the battery discharges. The company has replaced them.
If you want to take a stab at them, let me know and I will send you the link. Thanks! ❤
This must be an early version of the death beam. Heat the entire crowd just a little bit ;)
Fascinating bit of kit - I never thought about how these things worked, but I suppose any sort of two-way protocol wouldn't really be expandable to the tens of thousands of units at a big stadium gig, and radio would come with too much risk of interference with the audio, so good old-fashioned infrared probably makes the most sense.
I also wonder what those big IR LED emitters look like through a digital camera - would they show up on the footage on the big screens they have at concerts? The idea of bonus lighting effects only visible in photographs and video recordings sounds like something Radiohead might come up with...
This has got me thinking about other mass-audience gadgets now, next time I'm on the salvage team for a large festival, I'll have to grab a set of the "silent disco" headphones to send in, as they frequently get left behind on the campsite and I'd be interested to see one reverse-engineered.
it's probably a lot cheaper than korean concert lightsticks which almost every group has and can be synced to the concert halls equipment via radio, too
I got 3 of these from the Taylor Swift Eras Tour a few weeks ago. I have been wondering what I can do with them. So far, I was only able to get the LEDs to change slightly using IR from a remote control. I do have Arduinos and Raspberry PIs laying around and an IR blaster to mount on a breadboard. I think the problem with the IR remotes I was using is they pulse vs being continuously on.
Digital cameras should be able to detect IR rays and locate the source, now I'll be scanning footage of live shows to see if I can see it !
I guessed an infrared interface would be used. Similar to those little light pods that you can drop into swimming pools, fish tanks and flower vases that are infrared remote controlled
IR controlled? That would need a strong IR Transmitter for a large crowd. Imagine removing IR filter of a camera so you can really see this IR Transmitter. BRIGHT.
Most cameras and cell phones can see IR. Aim your TV remote at your camera for a test. I used to use this to see which optical fibers were lit at work, it annoyed me that iPhones had really good IR filters and wouldn't work so I had to carry a cheap digital camera.
My iPhone X detects IR on the selfie camera. @@davidg4288
I've been to a few weddings, where a similar device was used to 'stimulate' the wristbands of the attendees. I believe it utilized a form of PCM to address specific groups of bands. The emitters were scattered about the reception hall. It would be interesting to experiment with these.
On a slightly different, but related note. 3M has product, which they market under the name Optocom, that is sold to government entities, for the purposes of optically controlling Stop-n-Go lights, for emergency & public transportation vehicles. A modulated strobe, at a certain frequency is utilized to pre-empt a traffic intersection, for the passage of 'preferred' vehicles. Very interesting technology.
Almost certainly. Each unit is an addressable pixel in an audience-size bitmap image.
What I think what's most interesting of all: is how differently to actual the Public Domain perceives these to work, and it's right here in video comments is the source of the perception!
Would have been quite neat if it had a microphone so it could react to music if an infrared signal is not present. That way the user could wear it to other parties.
Multiple resistors for red being used as links is a good call. Is it a single layer PCB?
You can get a version with a microphone. I made a video about one.
Wow, no wonder the price of tickets for gigs is going through the roof.
That and the massive cost of running them.
As I Know Of The Pixmob Syatem Uses Another Dmx Controller That Controlls A Set Of Moving Heads With Ir Blasters On Them, These Pass Through Encoded Codes With Color And Other Stuff So They Can Like Draw Out A Image In A Cetarn Colour By Moving The Moving Head In A Design!
If you did rf, you could individually address these based on seat choice to do designs in the crowd.
This could be very interesting to explore with the Flipper Zero.
I spent half the video thinking "they could make the crowd into a video wall somehow couldn't they???" til he brought that up :P
Clive can you review those wifi ear pick borescopes?
I think I still have mine from the Coldplay tour sitting around somewhere
Thank you. Keep working, good luck.
Hey, I'd like to send something in for some reverse engineering (a smart LED bulb) but I can't find any info about that on your site - what's the best way to get in touch for more details?
I think he has a Facebook account.
I have a few different smart lamps here. They usually have a simple power supply, WiFi/bluetooth microcontroller and a specialist serially controlled linear current regulator chip.
I also want to send in an item for Clive to reverse engineer. Its very interesting. I couldn't find an email or postal address either.
@@bigclivedotcom I tried leaving a comment explaining what it is (teckin smart bulb with a broken screw base that I'd like to see if I can power off USB PD at 20V or something similar) but the comment didn't go through (or was automatically removed), oops!
Clive, do you want the latest model from the Music of the Spheres tour to compare? What i dont understand is how the make perfect hearts and stars in the audience? Are they shining IR beams in figures at the audience or how do they do it?
They use the equivalent of a huge tv image projector, except instead of light, it's IR. And instead of varying light brightness, it's high speed data packets.
So as the "tv lines" scan (light up) the audience, all the IR receivers pick up what ever data light pattern they need (individually) to show. Sounds complex, but actually quite simple.
Awesome Video big Clive
...was you at the coldplay concert? 😅
It's a shame we didn't get to see it in action!
I'm really surprised I haven't seen these in any japanese band performances, they love their glowsticks but afaik they are still being controlled by the audience by pushing a button. An infrared system would make much more sense in this case, I think.
This remind me of a similar device ‘Guardian Mockingbird Infrared Signal Light IR’
You might be able to trigger this in random ways with some standard IR remotes for TV's. etc. At least you should be able to get some sort of output...maybe a follow-up video or short trying my idea?
Id imagine theres also arduino code out there to do universal remote programming.
Though id imagine it wouldbe a lot easier for someone to go to an event that uses these with a ir reciever and try to intercept all the codes being used.
Also an Intellectual Property layer to get through while finding it. Any access code end up getting leaked into the public domain at some future point
interesting device but aaa cells and zinc chloride at that (eughhhh) can't see them lasting for too long depending on current and runtime obviously
So now I can only imagine Tom listening to really heavy rock music
Will you ever have more stage lighting videos?
I have been making a lot of short backstage snippets and posting them on Patreon while work was keeping me from my usual regular video uploads.
After concert I’m assuming they end up in people’s junk draws until the batteries leak then landfill lol
I think the P-FETs with that marking are also known as DMP2123.
Clive. I was watching the tattoo highlights tonight and saw the 40 (ish) ladies doing Scottish dancing.
When they first came out they were wearing blue dresses but near the end the dresses turned to pink or red. Were they just wearing white and the lights changed colour or was it a bit more interesting. 🤔 Im only asking because their skin tones didn't appear to change much or the cameras recording the event did what cameras do and adapt.
Also. Hello Vince. 👋😀
The dresses are two layer with neodymium magnets to hold them in place. At a key point, the dancers reach up and pull a tab and the blue layer drops down to reveal the pink layer.
@@bigclivedotcom
Thank you Clive, that I missed. Maybe they had been practicing? 😆
Hopefully one year I'll make it up there. I've done stage work but not to the standard that you all work to, so I won't be able to be backstage. 😀 I'll have to sit in the crowd! 😳
Now I'm going to look at them again. 😀👍
I assume that the IR transmitter is just an array of IR Floodlights?
Sometimes simple floods and sometimes moving heads for patterns.
They also use movinglights and gobos to do patterns
@@julianreverse That's actually obviously simple if you think about it. I'd previously assumed they use grid references or GPS!! doh
Each unit is a an addressed pixel in an audience-size bitmap image
WRONG! @@jagmarc
Thanks! If you get your hands on one of those "audience as a movie", please show :D
You can get the band to display different colors temporarily by using an off the shelf IR remote control.
The 7 basic colors (and off) from an RGB led could be expressed in three binary digits (000-111). The remote might be working just because those bits show up coincidentally in its commands.
I couldn't take my eyes from the faint smiley face on your left knuckle.
The PCB looks like a band-aid and since it's flexible it acts like one too.
The coldplay ones with a speaker used a AAAA cell, yes that's not a typo, quadruple A
AAAA cells are usually what alkaline 9V batteries are made of.
so very common actually
i do wonder if its possible to use those circuits and your own infrared light along with a bit of wires connected to some other stuff to use it as a remote control
thanks for the great video as usual. you know what would be fun? if you made a secondary channel with the "uncut RE process". I'm curious how you approach reversing somehting like this.
So theyd use them for maybe a group of shows that are each separate pay amounts so the people who didnt pay for certain shows the wrist band would light up red notifying they didnt to the security? Or just to make everybody glow certain colors during shows?
They are purely for a visual effect.
I have some Xylobands which I bought to repurpose to use as bands at my wedding reception, but went for some off-the-shelf chinese ones instead (time was of the essence and reverse engineering the code to drive the xylobands was taking too long). Would be happy to send one of each to you for a future video?
Are they controllable or music activated?
@@bigclivedotcom They're both controllable - the ones I bought came with a DMX-controllable radio transmitter. Not sure about the xylobands, but I believe they are also radio controlled - there was a project to build a transmitter but I didn't get as far as making it as some of the components for it were still on long backorder when I looked at it.
Hackers with IR equipped phones seem like they could cause a problem.
Well made landfill.
ooh got a couple old pixmob bands from singapore national day parade they are really cool
I feel a bit like the proper scientists who didn't invent the infinite improbability drive. I never get invited to those sorts of concerts. I imagine the IR environmental projector driven ones make for a memorable show.
Don't wait to get invited.
I still don't know exactly what a mosftet is? I know it's the black thing with three prongs, and I'm not sure what it does.
It is a switch controlled by a voltage. The voltage from the microcontroller is a low power signal. The mosfet switched the current to the LED, which is a high current.
Like a transistor or a relay, but not draining any current to open or close the switch.
It's a type of transistor that is turned on by voltage as opposed to current. Very sensitive and staggeringly high current switching capability.
I wonder why they went with PNP and P-MOS FETs. Why not use N-MOS to control LEDs GNDs. Anyone have any theories?
I'm not sure why they did that. Maybe based on an existing design or piece of software.
I've seen little light batons synced. Kinda wank to remove real interaction for something that looks better on camera. It was a Miku live show recorded I saw them on.
Do these things often use IR or have they been seen to use radio signals too? I have two from some concerts but I don't really want to open them up since they are elaborate and collectibles, I assumed they were radio controlled since they are single colour and all came on and off at the same time.
Some are IR controlled and some are wireless.
For a more modern version, how about taking apart one of the Miku wands?
(2×) AAA cells, 3 volts.
This must have been from far enough back that 100-200mah Lipo cells weren't cheap enough yet.
I would think today that these things would all have a small Lipo in them, and they'd probably work better, and be brighter, with the extra volt of headroom that the Lipo gives.