Late last night, a friend of mine (a very experienced lighting designer & master GrandMA programmer as well) came to visit. He loved the different looks, and especially the fact that nearly all of them could stand on their own, background music or not. We talked for a while about the behind the scenes gear that make everything run so nicely.
He asked what the ‘next step’ might be.
I had to think. There’s currently available several RGB mappable, flexible pixel mesh products in the professional market. And as they say, you can have anything in this world for money.
But – and this is perhaps more important – this is a home in a nice quiet neighborhood. It’s neither a rock concert nor a rave. And to this point, it still looks like classic Christmas lights, albeit slightly enhanced. I think that’s important and magical.
At least for now, that’s how it’s going to stay.
A few nights ago, I went out to get the mail and noticed a car parked across the street. They had their window open, and through it I could hear John Denver & the Muppets singing ‘Silent Night’ (see comments below). The car was packed with 8 year old boys and their parents. I asked the boys if they wanted to stand inside the tree and watch the patterns from there.
Super excited, they tumbled out of the car and over to the yard. As I parted the light strings so they could climb in, one of the parents remarked that their friend said they ‘had to come visit the diamond house before Christmas.’
“The what?” I asked.
“The diamond house. Because it’s so sparkly and amazing.” That made me smile.
Thanks for visiting! Enjoy the video and stills below.
In the fall of 2011, we were lucky enough to visit Walt Disney World in Orlando. We spent the day and evening there, and were gathered around Cinderella’s castle for the evening lighting ceremony. It was a magical moment, and the shaky cell phone photo taken above became the inspiration for our decorations this year.
(All photos in this post may be enlarged with a single click.)
2012 House + Lights.
Our goal this time was to create something beautiful, classy and memorable. We wanted still images which could stand on their own, plus sequences which could gracefully flow and be complemented by music.
I think we succeeded in grand style.
A couple of still photos are included above, and the boring technical details below. I’ll post some video and more stills in a week or two.
The stone face of the house is covered with warm and cool white LED panels. We lost track of the exact number installed. The CAD guy in our builder’s office claims that there’s about 944 square feet of stone which need to be covered. Each panel of lights measures 2 meters x 1 meter. Total LED count here is somewhere in the 22,000 – 24,000 range.
240 watts of LED floodlight.
~4,100 discretely controlled RGB bulbs on the 25′ tree.
~150 ‘sparkle’ lights (higher power, 3 x RGB emitters in a single package), also on the façade.
More RGB bulbs on the rooflines. Maybe 250 – 300?
28 (?) universes of DMX over ethernet, totaling ~ 5 megabits per second of data throughput.
Custom designed DC dimmers and Art-Net–> DMX bridge interfaces.
Lighting computer jam syncs to time code generated by audio computer, which keeps things nicely locked together.
Small radio transmitter broadcasting in stereo on 87.7 MHz.
A huge challenge was figuring out how to attach the lights to the house’s stone walls. It’s done in ‘dry stack’ style, which means that most of the stone sections stick out 1/2″ to 3/4″ in front of the mortar. So there’s lots of area to grab on to, but the shapes are very irregular, with often non-parallel sides.
I considered C clamps (too much money, didn’t want scratched rock) and plastic alligator work clamps (didn’t open wide enough, except for the super expensive ones). At 200-300 pieces required, cost starts to increase in a hurry.
While trolling through Lowes I found a perfect solution. Plastic gray PVC electrical conduit is available in many diameters. I bought 10′ sections of 3″ and 2.5″ pipe to test. Using a chop saw, I cut a section of pipe in narrow bracelet-sized pieces, with widths varying between 3/16″ and 1/4″. Then, I used the same saw, I cut about 50 degrees out from each circle, leaving me with a section of plastic which looked a bit like PacMan.
These sections were both very flexible and very strong. They easily stretch to the width of a stone section, but also grab tightly when released.
For $40 in pipe (and a lot of annoying plastic powder kerf), I’m absolutely thrilled with the results.
I designed a daughtercard which, through a short section of ribbon cable, mates with Parallax’s Spinneret ethernet module. And thus, a two universe Art-Net to DMX bridge was born. Parts cost for the daughtercard was just a few dollars. It works beautifully, running at an easy 44 frames per second on both outputs. If I get some time in January, and if there’s any interest, I’ll release the .spin code I used.. Size of the card is only about 1″ x 3″, which is nice and compact.
In this case, the panel lights use one universe and the floodlights are on the other.
The house face lights use 120 channels of one universe and the flood lights 12 of another. Crazy that it’s easier – at least in this case – to add a universe than to run more cable between here and there.
The stone face lights are controlled by five DC DMX dimmers I designed. Each drives 24 discrete outputs or 12 warm/cool pairs. Everything except the 24v/2.5A power supply fits on a 3″ x 5″ PCB card, which is nice and compact. The drive stages are rated at 2A each, but the panels only draw about 80 mA each. That leaves plenty of headroom, and no noticeable heat is generated anywhere on the card. Connectors on the left are for Neutrik’s Ethercon series.
Earlier this summer I previewed some different styles of net light. I was concerned because all of the AC-driven ones flickered annoyingly when I glanced my eyes back and forth across them. The flicker was at either 60 or 120 Hz, and it bothered me. It’d be easier, I reasoned, to go with custom panels which could be directly DC powered.
So I asked the factory to modify an existing design for +24v DC operation, which they did nicely. The dimming engine runs at a 5 KHz refresh cycle, which means the light output is both camera- and eyeball friendly.
Total data rate is ~ 5 megabits per second sustained.
Questions? Comments? It’s truly beautiful to see at night.
A few weeks ago one of my wife’s friends invited her to run an In-the-Dark-5K race, the proceeds of which benefit the Olive Osmond Hearing Fund. The late Olive was the mother of the famous singing Osmonds, and the grandmother of several of our friends in high school.
The race website said
We encourage everyone to wear their brightest colored running gear! Don’t forget your glow sticks and body paint! We will have black lights on the course to be sure that everyone will GLOW for HEARING!
Plus, other friends from long ago live in the same city (Logan, Utah). So we decided to take a road trip.
Back when she first heard about the race, I’d just taken delivery of 150 meters of white EL wire, which will be used in a Halloween project next month. I was testing the EL inverter in the workshop when she walked in. I suggested – half in jest – that we wrap her jacket in glowing wire for the run.
“But can it change color?”
“Well, not really,” I said sadly, recalling that that with a bit of electronic sorcery the phosphorescent hue can be shifted a bit to the left or right. And with some even more clever math, it can be dimmed. But that’s about it.
“No thanks then. Maybe we could use some of your extra lights from the yard tree instead?”
This seemed like a lovely idea. We sketched out some rough plans. Later that afternoon, she took a trip to a nearby outdoor equipment retailer and returned with great handfuls of flat black webbing, plus an assortment of plastic clips, latches and turnarounds.
The drawings and loose parts sat neatly on the shelf until yesterday, the day before the race.
We designed a form fitting vest / jacket skeleton using the webbing, white marking pens and a stapler. Once all the pieces were in the right place, the staples were replaced with machine stitching.
She also fabricated a small pouch to hold the controller and battery pack, and attached it to the vest’s rear, just below the shoulder blades.
The controller board was a a saved prototype from a different project. It was originally designed to drive 6 sections of RGB LED tape (18 channels total, 2A peak per channel, that’s a lot of LED tape) using either live DMX or data stored on an SD card. However, it was easy enough to repurpose a pair of pins to drive the LED node string.
Plus, it was free. Because as any accountant will attest, massive sunk costs can be completely ignored a few months later.
The card contains a DMX input stage, plus a few pushbuttons and LEDs for user feedback. I wrote a tiny program which captured incoming DMX at 44 frames per second, then saved the data to an SD card.
An interesting quirk of memory cards is that although they can be read from very quickly and consistently, the write process is not always as smooth. Even when writing entire sectors (512 bytes at a time) to the card, there can be random and variable delays incurred by the card’s internal electronics. 300 mS isn’t at all uncommon.
So the DMX capture code actually copies data to a very large circular buffer (at very precise intervals), and the SD write routine is triggered each time new data is ready. Since the input buffer is big enough, the two routines never step on each other’s toes. The result is perfectly stable recording and playback, even though both processes are running at different – and sometimes variable – speeds.
It’s an elegant bit of code, if only in a ‘you really had to be there’ sort of way.
Also extremely vital, because dropped frames are ugly and visually jarring.
An 8-AA, 2400 mA-H, NiMH battery pack supplies power. Its output feeds a cute little 7-16v input, 5V/2A DC-DC converter, which then powers the controller and LED string. Testing showed that the 42 LEDs pulled between 800 – 1500 mA depending on their state. The battery pack was tested for an hour under load, with no problems. The DC-DC converter didn’t become appreciably warm, which was nice.
Using a copy of Madrix Professional (again, sunk costs), I built a rough facsimile of the jacket’s LED layout.
The rest was easy. I arranged a cuelist of about 30 different looks, then let them cycle through over about 14 minutes total. Madrix output DMX through an ENTTEC USB Pro interface, and the jacket controller, in DMX capture mode, recorded each and every packet. In regular playback mode, the file is read and (if needed) looped.
“Are you wearing a bomb?” asked a curious onlooker before the race started, and while the vest was turned off.
(How do you answer that question, anyway?)
This comment piqued the interest of a nearby campus police officer. After we turned on the lights, he wasn’t as concerned.
2+ hour run time on a single battery pack
Not nearly as uncomfortable to wear as we expected it might be.
My wife, recovering from a shoulder injury, made good time through the run.
Overkill? Certainly. But it was fun to see people watch and smile.
Here’s some video from the race, then a few minutes inside which show some of the different patterns displayed.
The neighbors let us know, without mincing many words, that there will be Trouble if we don’t set the up the giant yard tree for Christmas again this year. We’ve been told that kids living on the opposite corner of the development would howl in protest if they weren’t driven home – the long way – via our little corner.
Fortunately, last year’s anchoring system proved so strong and sturdy that I plan to extend the tree to its full 25′ height. This means that there won’t be any extra node string ends on the ground this year, and the entire tree will be about 6′ taller.
But it’d be boring not to add something new to the collection.
For a few years, we’ve wanted to decorate the house with snowflakes of varying size and shape. Sadly, the daydreams have so far not materialized. Certainly there are a wide variety of pre-fab wireframe snowflakes available for sale. But I wasn’t terribly interested in the overall look.
A few years back, when we first started working with RGB LEDs overmolded on a cable, I drew up some simple snowflakes in the CAD program, then sent them to the shop which does all the metal forming for the products we sell during the day. A 48″ x 96″ sheet of .06″ aluminum, fully tessellated with snowflakes, cost about $400 for materials and laser time. This, by the way, was the after-hours cash price, so who knows the actual street price of the silly things. In this business, it’s often best not too ask.
(Note that all pictures below can be enlarged to full size by clicking on them twice.)
Advantages: Discrete RGB is cool, but there’s already almost 4000 nodes on the big tree.
Disadvantages: The LED package is nontrivially large. Wiring harness is bulky and adds about 3″ of depth to each snowflake. The wiring spaghetti backstage is ugly. Installing those nodes in aluminum holes is absolute murder on the fingers. For covering the whole house in snowflakes, the installation must be immaculate.
Plus, I didn’t just want bits of light arranged in a pattern. I wanted a look which was seamless, fluid and beautiful. So for 2012, the design constraints are
No nasty wiring harnesses
Continuous color / shape
Ability to appear nearly invisible during the day
(Optional) color changing capability
(Optional) relatively decent pricing, as quantity will approach 60-100 pieces in varying size.
So without further ado, here’s a summary of thoughts, experiments and misfires which have percolated through over the past few months.
Hypothesis #1 – Backlit Plastic
During a quick trip to Lowes I procured a series of translucent plastic sheets. One set, designed for use in commercial fluorescent lighting fixtures, was embossed with an interesting honeycomb pattern. This plastic can be cut by hand or by machine, so it’s possible to make any desired shape. Placing some RGB lighting tape leftover from the 2011 Superbowl project made an interesting effect. However, where the LEDs touched the plastic, their shape and spacing was clearly visible. Moving them farther and farther behind lowered the intensity but diffused the hot spots. 3-4″ seemed a good distance to work with. But making 100 fairly low-cost light boxes to ensure good diffusion just didn’t seem fun. Nor did mounting them on the side of the house. The winter winds here can take your breath away, so safety is always a concern.
Hypothesis #2 – Sideglow Fiber Optic Cable
Sideglow Fiber Optic Cable
This is a pretty neat product. While normal fiber optic cable is designed to transfer light from one end to the other with minimal losses, sideglow cable contains added magic which slightly disperses the light along its length. The resulting product can be used as a replacement for neon tubes, but in a much more flexible way. Traditionally, it’s driven by a 200 watt metal halide light bulb and a wheel containing dichroic glass filters.
Perhaps, I thought, the cable could be molded in the outline of a snowflake. This moves the effect away from ‘light blobs in a row’, which is important for this project.
Some folks stateside sell the stuff at what seems to be very inflated prices. Decent eBay sellers seemed to be from Asia, so I cruised Alibaba for a few hours in hopes of skipping the various middlemen.
The cable comes in varying thicknesses from 1-10 mm. I brought in samples of several sizes, plus an 18 watt (2 outputs, each with a 3W RGB LED) drive source.
The verdict? Nice but expensive. Price ex Asia for 6mm cable (the smallest which seemed to emit enough light to be useful) is $1 / foot plus freight. Any drive source less than 3W each of R, G and B is inadequate. 6mm cable has a bend radius of not less than about 40 mm. So fine detail is out. Driving high-brightness LEDs isn’t a big deal, but a properly packaged constant-current DMX-driven LED driver at 3 channels, even not counting our design time, would be ~ $30 each.
Thus making the house snowflakes a $5-6k project. Strike 2.
The driver would be relatively bulky as well. So that’s strike 3.
Also note that the photo above is terribly, terribly overexposed. That much brightness out the side of the cable doesn’t happen in the real world.
Hypothesis #3 – EL Panels
The next step in the quest for something low profile and evenly illuminated led to EL wire and paper. Electroluminescent wire has been around for quite a while, and made especially popular as part of dancers’ costumes, shown briefly between commercials on television talent shows. It’s fairly inexpensive, flexible and continuous in intensity. However, it doesn’t dim well, it’s only available in single static colors.
The existence of EL wire, however, leads the curious researcher to something called EL paper. It’s half a millimeter thick and can be cut to any shape with regular scissors. Drive voltage is 100+v, with current dependent on the paper’s area. It can be dimmed, but not easily. Still, this could be a neat, neat effect. Continuous light output in an arbitrary pattern.
I found a few factories who could make panels 2 meters wide x 1 meter tall. Sadly, the best pricing I could find, even when buying in largeish quantities directly from the maker, hovered around $0.023 per square centimeter. Add designing a DMX-driven high voltage outputter (cough, cough… these don’t seem to even exist!) for each snowflake and the project becomes ferociously impractical. Plus, still single color per panel.
Hypothesis #4 – Edge Lit Acrylic
Here’s where things become very interesting. Folks in the sign-cutting industry have, for a long time, made some striking art by edge-lighting pieces of plastic. Further, designs can be etched in to the plastic, either using a stencil and sandblast method, a CNC router or laser ablation. Each section of the plastic disturbed in some way catches light.
I bought from the local plastic shop four pieces of 3/8″ cast acrylic plate. 3/8″ is expensive, but it’s also the same thickness as my RGB LED tape. These were precut in squares, one each of 6″, 12″, 18″ and 24″. Retail price for the plastic was $70.
These guys have a nice little Epilog laser for cutting and etching, but its table size was too small to handle the 18″ and 24″ pieces. I was referred instead to a shop which owned a drop-dead-gorgeous 150w Kern Laser, featuring a cutting area of 50″ x 50″. Plenty of size and power for this project.
I emailed over some vector graphics files and we were in business.
We happened to have some extra high-power DMX dimmers in the shop – prototypes from a custom design built for a touring concert group. These six-channel dimmers have a super heavy duty output stage, and digitally dims at a frequency far higher than the broadcast video cameras they were using. Each of the two RGB banks can handle 10 meters of double-density (60 LEDs per meter) RGB LED tape. For just fooling around, this is massive headroom.
I wrapped two snowflakes in LED tape and turned on the dimmer. The results were spectacular. Smooth, even illumination everywhere the snowflake pattern was ablated, and complete transparency otherwise. The etched patterns are nearly invisible, even in daylight. The prototypes have a very thin profile and are exceedingly simple to drive. Each snowflake, even at full brightness, requires maybe 300 mA per color at 12v. Over the next month or so, I’ll gin up a dozen or so 36-channel (12 x RGB bank) dimmers with an Art-Net front end. Each snowflake will connect to the dimmer using a length of thin and inconspicuous CAt5 cable. These will mesh nicely with the Art-Net infrastructure already in place.
As an interesting side note, it’s actually less expensive, component-wise, to design using ethernet than to include a properly optically and galvanically isolated input stage for DMX.
There’s only one downside at this point: retail price for the laser time was $225. Even divided by four snowflakes, it’s way too much money. But the look is stunning and perfect, so we’ll figure out a less expensive way to proceed. Perhaps even the vinyl stencil + sandblasting method will prove affordable at this scale. I need to investigate whether a CNC router can produce roughly the same effect but at a fraction of the cost. It may be a good excuse to buy a smaller (36″ x 36″) router just to have. Or a biggish laser table.
Anyway, stay tuned for fall. The flock of snowflakes should be spectacularly beautiful.
If anyone has suggestions for pulling off this look without totally breaking the bank, I’d love to hear from you in the comments below.