

Coldplay Wristbands Turn Audience Into Giant LED Display - kator
http://mashable.com/2012/06/14/coldplay-xylobands/

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dkersten
Myself and my brother built a prototype of a very similar wristband last year,
completely independent of these and without knowing about them (we built ours
in the summer, we first saw Coldplay's in autumn). At first we were pretty
dismayed and annoyed to see that somebody had patented the concept (we never
looked into exactly _what_ the patent covers), though one of the guys we were
working with has connections in the Coldplay management team and assured us
its fine for us to continue.

But then we thought about it some more and realised that we didn't need to,
that the coldplay wristbands have some flaws (for what we wanted to do with
them) that we can better tackle in other ways. Our goals are very different
from Coldplays anyway - they seem to be using their wristbands more to make
the DVD look awesome than to please the crowd present (though theres obviously
some of that too). Our goal was always interactivity and engaging the crowd in
more direct ways.

So we cooked up a similar concept which is not only _more_ suited to
interacting with the crowd, but also less expensive to produce. So win-win.

The wristbands are cool and maybe we'll still do something with that
(depending on the patents of course - the Xylobands don't really do exactly
what we want, so we'd probably want to build our own anyway) but we did the
startup thing and pivoted and came up with something better (for our
purposes).

 _The laptop would be connected by cable to a transmitter box and antenna.
These are supplied by us on a free rental basis with a £500 refundable
deposit._

Our own transmitter cost us about US$20 to build. Sure, it could only be
controlled by USB-MIDI (while afaik theirs supports stuff like DMX), but meh,
it wouldn't require a £500 deposit.

In any case, I'm now repositioning myself as more of a backseat tech
consultant for this project rather than hands on engineer as I'm working on an
unrelated startup and don't have time to stay involved in the day to day
building of audio/visual gadgets, so over the next few weeks I hope to finish
off a few more prototype devices and then leave the production up to someone
who has a better idea what their doing.

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sjwright
The most obvious improvement they could have made would be to vary the
transmitter's power so that they could create a (very very approximate) circle
of light around the transmitter point. Raise and lower the transmitter power,
and you increase and decrease the size of this light circle. Great for
pulsing, explosion style effects.

Different transmitters in different locations could trigger different colours.

Thinking further, they could have introduced multiple low power transmitters
across the audience, or highly directional transmitters pointing at the
audience from a central spot. You could then create colour clusters, rainbows,
spinners, rather than just a uniform effect.

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zeteo
Fun project:

\- add an IR LED to each band and make it transmit a unique 2 byte MAC address
on the IR channel(s)

\- get a high speed, high res panoramic camera and some good computing gear

\- figure out from the sequence of frames where each MAC address is

\- control individual pixels

~~~
mbell
\- add an IR LED to each band and make it transmit a unique 2 byte MAC address
on the IR channel(s)

I would think it would be easier to just put a serial number bar code on the
back lining up to a MAC of sorts and scan it when the person arrives
correlating the the serial number to their seat. That should give you all the
location information you need, at least for the non-standing room only areas
of the stadium.

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mbreese
I'd be more impressed if they were able to individually (or in small
geographic groups) address the wristbands. Then you might be able to get some
sort of interesting visualizations as opposed to pulsing.

But, it is a neat trick, and certainly looks cool from above.

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brittohalloran
They need to incorporate location of the wristband with some sort of
triangulation between transmitters. Then they can make it an actual display.
I'm sure this will happen in the not too distant future and I'm excited to see
it.

~~~
cjdavis
Using highly directional antennas on the transmitter should be able to
accomplish similar results without increasing the cost of the wristbands.

~~~
tathagatadg
What if these bands are paired to phone via bluetooth so that the base station
can send commands to the phone (through the mobile network) which in turn
relays it to the band - would it allow a more fine grained control with
acceptable latency?

~~~
mbell
Latency would be huge with that setup. 900mhz radio has more than enough range
and bandwidth to handle 50,000 - 60,000 devices updating several times a
second. I've used LSR [0] modules in the past for prototyping and they have a
gateway that would allow you to control the entire thing through ethernet so
any computer could run the program and just spit out ethernet packets to send
control information.

[0] <http://www.lsr.com/>

------
VMG
More info: <http://xylobands.com/glowbands-product_info.php>

> How do they work?

> Xylobands™ are operated using our proprietary software that can be
> downloaded onto your laptop.

> The laptop would be connected by cable to a transmitter box and antenna.
> These are supplied by us on a free rental basis with a £500 refundable
> deposit.

------
pavel_lishin
Anyone reminded of the scene in Snow Crash when YT calls in a Code, and
everyone at Vitaliy's concert thinks it's a visual effect?

------
viggity
I went to their website to try to find pricing but they require contact info.
Anyone have any idea on how much these thing cost when you're purchasing in
bulk?

~~~
joezydeco
Chris Martin is quoted here[1] as saying the bands are costing GBP 400,000
(USD $640,000) a _night_. $20 a band!

Looking at the teardown[2] there's a radio receiver chip, microprocessor,
couple of discretes/inductors/popcorn, then the plastic case and band with hi-
bright LEDs and a battery. I'm thinking most of the cost is in the LEDs and
battery need to drive those LEDs for two hours.

[1] [http://blog.chron.com/celebritybuzz/2012/06/coldplay-
spends-...](http://blog.chron.com/celebritybuzz/2012/06/coldplay-
spends-640000-per-night-on-wristbands/)

[2] [http://hackaday.com/2012/02/19/ask-hackaday-did-you-catch-
th...](http://hackaday.com/2012/02/19/ask-hackaday-did-you-catch-the-grammys/)

[3] Top _that_ , Bono! =)

