What I've been up to in Hong Kong

[mikeselectricstuff]

Each snowflake is made up of 60 LED strips, each containing 6 RGBW LEDs and a PIC12F1501. All fixed together with plastic rivets and interconnected with SIM card connectors.
Total 270 snowflakes, 16,200 PICs, 97200 LEDs

[xrunner]

What an electronic work of art - very impressive. 

[alex89]

Very clever design    Have you had any issue at all with connectors reliability ?

[mikeselectricstuff]

Very clever design    Have you had any issue at all with connectors reliability ?

not yet.....

[Miles Teg]

Ho yes, very intersting connection system.
How did you get the idea? 

[ataradov]

Did they do it just for Christmas/New Year? Or it is actually going to be there for some time?

[coppice]

Very clever design    Have you had any issue at all with connectors reliability ?

The real answer will come on 12th night, when the whole thing is turned off.  Interestingly, this display is just for Christmas. It is common in HK for Christmas decorations to be designed so they can be reconfigured in early January as an appropriate Chinese New Year's display (i.e. remove anything white, which symbolises death and funerals in Chinese culture, and play up the red, which symbolises good fortune).

Mike employed some rather smart reuse of standard parts in this design. The contacts are a bare SIM card connector (i.e. just the gold pads, with no metal card retainer part) on one board, pressing against ENIG pads on another board. Plastic pop rivets hold the two boards together, and the whole thing seems to work well. Mike used quite a lot of rivets, so the structure is pretty stable. I watched several snowflakes being assembled. This consisted of

• Three people furiously pressing pop rivets into holes for several minutes
• A programmer sending patterns around the segments of the flake to check each one
• The three people prodding the rivets on any flake segment that misbehaved - every failure I saw was due to something not being properly pushed into place
• A clean run of the pattern test
• Storage in a custom made crate, for delivery to Pacific Place
• Repeat hundreds of times over a couple of weeks

After any initial assembly issues were addressed the flakes seemed rock solid.

Pacific Place is one of the most up market malls in Hong Kong, so this is a prestigious place to be.

[mikeselectricstuff]

Did they do it just for Christmas/New Year? Or it is actually going to be there for some time?

Currently only til Jan 4, but they are talking about using the parts from all 5 sections to make a big permanent display where th etree currently is some time next year

[mikeselectricstuff]

• A programmer sending patterns around the segments of the flake to check each one

The primary purpose of that was to program the individual addresses into each strip
The jig uses a similar modular construction to the flake so it can easily be reconfigured to make different shapes

If we do re-use the PCBs in another form  I think we'll need to make a fixture to pop all the rivets out, as it's much more work getting them out than in.

[iampoor]

How are all of these powered?

Very impressive. 

[coppice]

How are all of these powered?

Very impressive. 

With electricity. Surely the interesting question is how much power do 100k LEDs require.

[mikeselectricstuff]

For first 4 frames we are maxing out all available  sockets  if we did 100%rgb+w , about 8kw from memory. Tree about 5.5kw

[calzap]

Mike,

Very impressive and creative.  Was everything preprogrammed or can it be reprogrammed in the sky? Are the suspensory cables (at least some of them) also power conductors or is suspension independent of electrical supply?

Mike in California

[TerraHertz]

That's neat.

It looks like all the hexagonal units are independently suspended, and not directly interconnected?
Is the design also able to work with extended regular matrices?
Is there any processing power on the modules or are they all just commanded from something central?

If something like this could be connected together in an extended matrix, with a bit of processing in each node, you could do cool chaotic system stuff, like Game of Life. I guess there'd have to be multiple power feed points though.

I really like that interconnect idea.
Hmm... if the hubs were a bit flexible (and came in 6 & 5 arms) then geodesic structures would be possible. Though, then there'd have to be several different length segment pieces.

[brabus]

Very neat, very clever and very nicely made, as usual!   

With a total power in the range of 8 kW, I would be very curious to see the power distribution strategy.
I had color drift issues when driving a chain of 120 WS2812: the first LED had 5.00V, the last one barely 4.60V --> the first one was full bright white, and the color drifted progressively towards light red to the end of the chain! 
I had to struggle to bring additional low resistance 5V paths to various points of the string.

[DanielS]

With a total power in the range of 8 kW, I would be very curious to see the power distribution strategy.

I'm guessing that each hub (36 LEDs) has its own power feed. That's still ~1600A total at 5V, which means either quite a few AC-DC converters or massive 5V bus bars hidden behind those top form supports.

[Artlav]

Pacific Place is one of the most up market malls in Hong Kong, so this is a prestigious place to be.

Please tell me he is not getting paid with exposure...?

[Macbeth]

Great stuff Mike,

I especially like the fact that dad can easily tear it apart and pack it into the box of baubles and tinsel and leave it up in the attic until it comes out again next year 

I hope you got paid for this as an "art piece" rather than an "electronics project" as one of them seems to command a lot more cash than the other!

[alanambrose]

Hmmm, the MES law of LED count vs time suggests a million LED project in the not too distant future?

[mikeselectricstuff]

With a total power in the range of 8 kW, I would be very curious to see the power distribution strategy.

I'm guessing that each hub (36 LEDs) has its own power feed. That's still ~1600A total at 5V, which means either quite a few AC-DC converters or massive 5V bus bars hidden behind those top form supports.

Each strip has 3 rgbw LEDs per side, in series to run from 24v

[coppice]

Pacific Place is one of the most up market malls in Hong Kong, so this is a prestigious place to be.

Please tell me he is not getting paid with exposure...?

If you are creating artworks, your main exposure to prospective clients is your existing artworks, and being in prestige venues helps a great deal.

[mikeselectricstuff]

That's neat.

It looks like all the hexagonal units are independently suspended, and not directly interconnected?

Each is seperately hung, but pairs are linked together to lock the rotation

Is there any processing power on the modules or are they all just commanded from something central?

No processing - it's just a pixel display driven by an external system. Each drop cable carries 24V power and TTL data at 125kbaud. Up to 12 flakes plug into splitter boxes on the frame, which distribute (and fuse)  power, and split data out from four 2Mbaud RS485 buses.

Hmm... if the hubs were a bit flexible (and came in 6 & 5 arms) then geodesic structures would be possible.

Or you use rigid corners and longer, more flexible PCB strips.
Stay tuned 

[mikeselectricstuff]

Hmmm, the MES law of LED count vs time suggests a million LED project in the not too distant future?

It's a bit random - I think the biggest to date is Heathrow airport at about 350,000 LEDs  http://cinimodstudio.com/project/emergence/

[amyk]

Very neat, very clever and very nicely made, as usual!   

With a total power in the range of 8 kW, I would be very curious to see the power distribution strategy.
I had color drift issues when driving a chain of 120 WS2812: the first LED had 5.00V, the last one barely 4.60V --> the first one was full bright white, and the color drifted progressively towards light red to the end of the chain! 
I had to struggle to bring additional low resistance 5V paths to various points of the string.

If it's an art installation, that could be a bonus feature - gradients for free!

[mikeselectricstuff]

Very neat, very clever and very nicely made, as usual!   

With a total power in the range of 8 kW, I would be very curious to see the power distribution strategy.
I had color drift issues when driving a chain of 120 WS2812: the first LED had 5.00V, the last one barely 4.60V --> the first one was full bright white, and the color drifted progressively towards light red to the end of the chain! 
I had to struggle to bring additional low resistance 5V paths to various points of the string.

If it's an art installation, that could be a bonus feature - gradients for free!

One advantage of art projcts as opposed to commercial products is that things that might be regarded as faults can be re-interpreted as artistic quirks