
Show HN: A high-tech floating Christmas tree with more than 2000 RGB LED's - mixmax
http://www.maximise.dk/the-high-tech-floating-christmas-tree/
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oldmanjay
Floating on water in a barge, not to spoil anything here. I was half hoping
for hovertrees.

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Cerium
Very cool none the less. At night, when the water is black it does look a bit
like it is floating.

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tlrobinson
Very nice.

Did you compare OctoWS2811 to any other RGB LED controllers like FadeCandy or
PixelPusher?

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mixmax
no, but primarily from a "we already know this" point of view.

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jwatte
Nice! I just put eight meters of dotstars in my tree, but that's only 480 rgb
LEDs. And indoors :-)

Did you consider DC/DC regulators for stabilizing 12V? 10A per bus could be
done with inexpensive boards?

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chrlilje
That was a mistake by me in the design process - I simply forgot, that the
charge voltage of battery systems are 14.7 V - And when I tested the diodes,
they were not very happy getting more than 13 V.

We should have gotten a stack of cheap DC-DC converters to keep the voltage at
12 V for each strand of Diodes. But we realized the mistake too late for
another Aliexpress-order, so we just had to go with a solution with parts from
our stock.

..next year we will have lots of better ways to do things.

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onion2k
Fun project. If you're interested in messing with RGB LEDs in a simple way, I
can recommend Blinkstick's Pro controller. It's a WS2812 in a nice USB housing
with some decent libraries in a variety of languages. I've been using one with
chrome.hid (Chrome's USB interface) -
[https://github.com/onion2k/BlinkstickChrome](https://github.com/onion2k/BlinkstickChrome)

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GeorgeHahn
Alternatively, if you need a bit more power, there's Fadecandy from @scanlime:
[https://github.com/scanlime/fadecandy](https://github.com/scanlime/fadecandy)

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saurabhtandon
This is definitely an interesting project. I liked the video projection and
extending battery life to 2 days. Kudos to the team :)

However, could you have a clean power source? I mean there was water, wind and
the barge was floating. Is there a way you could have recharged the batteries
without the generator? I know the power requirements was high but just
wondering. Small wind turbines may be (assuming cost was not an issue)?

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mixmax
The obvious choice would be solar, except for the fact that at this time of
year we only get around 6 hours of daylight in Copenhagen. Winter solstice was
yesterday.

Wind might work, a windmill for boats might be able to give us the power
needed. At least it would extend the battery time. Only problem with that is
that they're quite expensive, and we didn't have much of a budget to begin
with.

Maybe next year... There were so many things we'd like to have done, but
didn't find the time and money for. One of them was an app or a dedicated
webpage where you control the lights on the tree. Maybe even some kind of game
where you play some game on the tree against other players.

Lots of possibilities, but limited time and money...

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walshemj
One option if you have suitable waves would be to produce a hinged raft and
have the flexing motion of the raft produce electricity via hydraulic motors
like some wave power systems.

Is there enough tidal flow to use sub merged turbines and use the flow of the
water past the moored raft?

Can you tell I used to work in a Hydrodynamics lab :-)

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mixmax
interesting idea - and very much in the spirit of the project.

It's a pretty closed off harbour so there aren't really any waves, and there's
almost no tide so not much flow past the raft either. Especially since it's
moored in a sidechannel. So it probably won't work :-(

Kudos for the idea though.

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rodionos
I need more of these just to remind me what winter should look like. It's
absolutely devastating to have no snow whatsoever for Xmas.

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deanclatworthy
Looks great Max! Was this work commissioned by the city?

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mixmax
Thanks!

No, it wasn't coommissioned, but we got a 25.000 DKKR grant for making it. We
spent it all on trees, barges and electronics, so noone made any money from
it. But it was a really fun project.

