This is why I've not had much time for videos recently... - Page 1
Forum section: electronics / projects

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2014, 03:49:15 pm
content: A fun little installation at London Heathrow airport's new Terminal 2 - opening next week :http://cinimodstudio.com/project/emergence/350,208 LEDs, 19,456 LED drivers, 170 PIC32's, 600 metres of PCB, about a mile of wire, 5 kilowatts of PSUs, and some carbon fibre

author: Wh1sper
author_rank: Regular Contributor
timestamp: May 30, 2014, 03:54:25 pm
content: Whow!awe-inspiring!Very very nice!Amazing Women acceptance factor, I guess1 ;-)

author: Post_Apocalyptic_Inventor
author_rank: Contributor
timestamp: May 30, 2014, 03:57:45 pm
content: Wow. This a true piece of art. I guess I have to take a plane to London and see this first hand. Did you design the shape of it too, or did you "just" contribute the electronics ?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2014, 04:03:57 pm
content: Quote from: Post_Apocalyptic_Inventor on May 30, 2014, 03:57:45 pmJust the electronics and low-level firmware. And fighting the mechanical people to get space to put stuff in. Actually had to go to TSSOP packages for the PICs!

author: jaxbird
author_rank: Frequent Contributor
timestamp: May 30, 2014, 04:07:02 pm
content: Beautiful workI'd have to say I also love these at the Singapore Airport, they have a few of them installed:Edit: how does one embed a video?

author: josem
author_rank: Regular Contributor
timestamp: May 30, 2014, 04:16:51 pm
content: Wow, I was super impressed when I saw that video earlier in the week. Excellent work.Out of curiosity what kind of LEDs go into something like that?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2014, 04:30:49 pm
content: Quote from: jaxbird on May 30, 2014, 04:07:02 pmYes - that's probably the best one I've seen. Similar to the one at BMW museum at Munich - I've seen the latter in person - most surprising thing was how quiet it was - I suspect the wires pass through a layer of soundproofing at the top.What puzzles me is how they stop air currents causing swaying - the Munich one is very enclosed, with only a fairly small viewing gap, but the Singapore one looks a lot more open. My guess is they may have fluid in the drops to help damping.QuoteJust paste the URL - with youtube you sometimes have to take the 's' out of https

author: leppie
author_rank: Frequent Contributor
timestamp: May 30, 2014, 04:40:26 pm
content: Wow, very nice! Those LED's look so tiny.I cant imagine the effort going into programming them to be so beautifully synchronized.(tears of joy)Mind telling us how it works?Quote from: jaxbird on May 30, 2014, 04:07:02 pmWow again! Looks like 1000's of LED rain drops on tiny space elevators! Is that how it is done?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2014, 04:41:09 pm
content: Quote from: josem on May 30, 2014, 04:16:51 pmhttp://www.osram-os.com/osram_os/en/products/product-catalog/leds-for-general-lighting/duris-e-3/lcw-jnsh.ec/index.jspVery bright - I usually only need to run them at 10mA, but very cheap - About GBP 0.035 in 50K+ volumes. The distributor I buy from often has >1,000,000 in stock, and lets us pick matching bins from the stock they have ( if you see this install in person you may notice this didn't quite work out this time..!)I must have a count up but I think I must have designed close to a million of these into various installations over the years.

author: jaxbird
author_rank: Frequent Contributor
timestamp: May 30, 2014, 04:47:11 pm
content: Quote from: mikeselectricstuff on May 30, 2014, 04:30:49 pmThanks, yeah, sorry I don't want to hijack or detract from the wonderful sculpture you co-createdFirst time I saw the Singapore one in person I thought they much have wires in both ends, but no, definitely only at the top, it's hanging over a glass floor. The drops must be fairly heavy as the whole airport got at least some airflow with heavy air-conditioning.Did you use WS2811 or similar for the Heathrow sculpture?

author: DavidDLC
author_rank: Frequent Contributor
timestamp: May 30, 2014, 04:51:41 pm
content: Excellent work Mike ! Pretty amazing.David.

author: MrAureliusR
author_rank: Unknown
timestamp: May 30, 2014, 04:54:07 pm
content: Wow Mike! Incredible work!Is the source code going to be open-sourced? I love to see the software implementation. I'm assuming some of your recent videos were rather 'cryptic', for example the bucket water stress test was probably for these PSUs?

author: KedasProbe
author_rank: Frequent Contributor
timestamp: May 30, 2014, 04:58:16 pm
content: Looks very nice.Can you control the brightness of each group of 3 leds from one control centre?How many leds are there in one bar?

author: JeanF
author_rank: Regular Contributor
timestamp: May 30, 2014, 05:00:52 pm
content: wow, very impressive, two thumbs up !When you are making this kind of things (this one in particular) do you physically assemble and connect the modules in the real installation, and take care of all the "on the field" problems in person, or are there other guys doing that when you're finished with the design ?great work !

author: leppie
author_rank: Frequent Contributor
timestamp: May 30, 2014, 05:07:13 pm
content: Quote from: jaxbird on May 30, 2014, 04:47:11 pmI cant believe that. Imagine the clusterfuck they would have to deal with if even 1 gets tangled.

author: max_torque
author_rank: Super Contributor
timestamp: May 30, 2014, 05:08:20 pm
content: 350K LEDS! Must be nice to have a project where you can go through the inventory lists of the major component suppliers and immediately qualify for their biggest "volume" discounts!(compared to more normal projects where you like only need 3 of something, but have to buy say 10....... ;-)

author: jaxbird
author_rank: Frequent Contributor
timestamp: May 30, 2014, 05:18:59 pm
content: Quote from: leppie on May 30, 2014, 05:07:13 pmThey are spaced further apart than you'd think, but anyway, I'll be at the Singapore Changi Airport again in about 2-3 weeks, so I'll be happy to do a few extra checks and pictures/videosBut yeah, sorry, let's not hijack Mike's thread.

author: mariush
author_rank: Super Contributor
timestamp: May 30, 2014, 05:26:19 pm
content: hmm..350,208 LEDs, 19,456 LED drivers ... so 18 leds per driver ... can't quite figure the number of strips, because i'm not sure those blue strips are included in the count.Going with nice "round" numbers, let's say 64 strips, as that would make 19456/64 = 304 drivers per strip, or 1824 by 3 leds ?Could you give some details about how that software they mention "talks" to the strips? They make it sound like some technological wonder but it looks to me like it's just some rendering on repeat.Just at a very quick though, since the strips seem to be of the same size, would the software just render a picture and then split it into 1824 strips and send it through some serial links and sync everything with some clock ?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2014, 06:03:49 pm
content: OK.....Each arc comprises four 1 metre long PCBs, two on each side.Each PCB has 32 TLC5973 drivers, each driving 3 pixels of 6 LEDs from a 24V supply.The TLC5973 is similar in concept to the WS2811, but better in a number of ways - it has 12 bit resolution, which is essential for monochrome to get a decent greyscale, the protocol works over a range of clock frequencies, and with some sneaky tricks can be driven from an SPI port.And it's from TI and not some obscure Chinese supplier.At the centre of each arc is a control board that drives the 4 strips. This has a PIC32, and 2Mbytes of SPI flash memory. This memory stores pre-rendered image frames - these are things like varying lengths of bar, sparkle patterns etc.This allows 60fps updates using only 29 bytes per frame per arc, massively reducing teh bandwidth required. It takes about 5 minutes to upload the content to the flash, but it only needs doing once, and can be loaded to all arcs simultaneously.These parameters select things like frame number, rotation, brightness and various mix modes to combine up to 5 frames into the final displayed image line.The arc controllers receive a 100kbaud serial datastream from splitters located near the spokes.Each splitter takes a 1MBaud RS422 datastream containing data for a whole ring, and extracts the 29 byte data packet for each of the arc controllers connected its 9 ports. There are 2-6 splitters per ring. The splitters also handle 24V power distribution and polyfuse protection to each arc, and also a dimmer for the blue LED strip on the inside of the rings.This is all fed from an 8-port USB-RS422 interface, of which only 5 ports are used - one per ring, so the whole thing runs off a single USB port, with a total data rate of around 260kbytes/second.The data is generated using realtime GPU particle simulation with a 3D model of the physical positions of each arc - I didn't have anything to do with that so don't know much about it.

author: ElectricGuy
author_rank: Regular Contributor
timestamp: May 30, 2014, 06:19:47 pm
content: Great Scott!

author: mariush
author_rank: Super Contributor
timestamp: May 30, 2014, 06:20:20 pm
content: Wow... cool idea with those pre-rendered image frames, I didn't think of that.Thanks for the details, quite interesting to see what works behind such projects.

author: jaxbird
author_rank: Frequent Contributor
timestamp: May 30, 2014, 06:20:42 pm
content: Quote from: mikeselectricstuff on May 30, 2014, 06:03:49 pmWhat you mean Worldsemi Co., Limited is less reputable than TI ?Nah, fully understand you choice.. the WS2811 do have issues with low level grey scale. They are incredibly cheap though, even the Chinese will start throwing them at you when you ask for a discount on LEDs.Impressive sync and integration of so many LEDs

author: lewis
author_rank: Frequent Contributor
timestamp: May 30, 2014, 07:23:37 pm
content: Awesome job Mike, where do you get all this lovely work from? All I seem to get to do on the custom side is pain-in-the-arse stuff!

author: max666
author_rank: Frequent Contributor
timestamp: May 30, 2014, 07:34:43 pm
content: Very cool, Mike!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2014, 08:11:40 pm
content: Some pics.The arc PCBs are resin encapsulated in pairs, mostly to avoid creating dust traps and protect from damage during cleaning (no I don't know how they plan to clean it - someone else's problem!)

author: aroby
author_rank: Regular Contributor
timestamp: May 30, 2014, 08:37:08 pm
content: Very impressive, thanks for sharing the details. I like the arcs made from carbon fibre.I'm still waiting to find out where your iPod nano screen project ended up ...Anthony

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2014, 08:50:46 pm
content: Quote from: aroby on May 30, 2014, 08:37:08 pmIt was installed in New York a couple of months ago - there is supposed to be a video being made about it - hopefully soon.

author: zapta
author_rank: Super Contributor
timestamp: May 30, 2014, 08:53:34 pm
content: Mike, can you tell us about the process of creating the light 'dance'? What kind of people made it, what software tools they used, how much work does it takes, etc. I can understand having many addressable LEDs but how to choreograph them is beyond me.Dave, Chris, have an Amp Hour with Mike with more details?

author: CrabxCore
author_rank: Contributor
timestamp: May 30, 2014, 08:59:59 pm
content: This is a beautiful installation. Looks great!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2014, 09:01:01 pm
content: Quote from: zapta on May 30, 2014, 08:53:34 pmI didn't have much involvement with this - here is some infoQuote

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2014, 09:39:32 pm
content: Quote from: JeanF on May 30, 2014, 05:00:52 pmDepends a lot on details - I try to design stuff to be fairly straightforward to plug together, and be pretty idiot proof, e.g. even though everything plugs together, I always make sure that all data lines are protected from shorts to the 24V (or whatever) supply, or any plausible reverse/incorrect connection. Also make sure there are spares of everything - not being able to finish an install due to a damaged part is bad news. (We once nearly couldn't finish an overnight install at a shopping centre for lack of a couple of M3 screws - fortunately someone found some in the bottom of a toolbox!)I'm usually there to supervise, & usually end up doing the fiddly bits & testing myself.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2014, 09:45:27 pm
content: Quote from: jaxbird on May 30, 2014, 06:20:42 pmCost of drivers is not a big issue compared to other costs on something like this. I think the resin encapsulation cost about the same as the PCB, parts and assembly.And that's before you start on the carbon fibre... I paid less for my house.

author: jancumps
author_rank: Unknown
timestamp: May 30, 2014, 09:53:24 pm
content: I'll be in Heathrow mid June.Flights from Belgium normally don't go via T2, but I'm going to check out anywho how I can get close to this installation.If it's in he checked-in area, my chances are slim.Well done, MES.

author: David_AVD
author_rank: Super Contributor
timestamp: May 30, 2014, 10:12:02 pm
content: Very impressive Mike. Thanks for sharing the end result and some construction details.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 30, 2014, 10:22:42 pm
content: Quote from: jancumps on May 30, 2014, 09:53:24 pmIt's in T2 Departures so you'd need to be going somewhere that flies from T2

author: pickle9000
author_rank: Super Contributor
timestamp: May 31, 2014, 01:35:22 am
content: Wow! That's really impressive, congratulations on a job very well done.

author: SPRX
author_rank: Regular Contributor
timestamp: May 31, 2014, 02:53:07 am
content: Excellent piece of work, and Looks Great !!!Simply Awesome !!!

author: VK5RC
author_rank: Unknown
timestamp: May 31, 2014, 03:21:14 am
content: Lovely work, you should be proud of the final result!Did you keep a few spare 'segments' as keepsakes? I hope so!

author: Electr0nicus
author_rank: Regular Contributor
timestamp: May 31, 2014, 03:27:44 am
content: Wow what a impressive project. I love stuff with crazy numbers of LEDs. And also thank you mike for giving us a view "inside" and how that complete system works.

author: jeremy
author_rank: Super Contributor
timestamp: May 31, 2014, 03:48:07 am
content: Beautiful!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 31, 2014, 07:33:47 am
content: Quote from: VK5RC on May 31, 2014, 03:21:14 amYou always need to make spares for stuff like this, as the cost/time to make more if something dies or gets damaged during install is way higher than adding a few to the main production batch.

author: firewalker
author_rank: Super Contributor
timestamp: May 31, 2014, 08:02:12 am
content: Amazing!Any video from the cube installation?Alexander.

author: CBP
author_rank: Contributor
timestamp: May 31, 2014, 09:38:07 am
content: Truly impressive work - out of interest how much time would you get from instruction to completion for a project like this? I'm just wondering whether you get a lot of test time on the bench before everything gets hoisted into the air.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 31, 2014, 09:42:59 am
content: Quote from: wilfred on May 31, 2014, 09:03:49 amThis is one of the eternal battles I have with customers, especially the ones less experienced in large-scale installs. They come up with something that is completely unmaintainable, then I tell them what things they need to change, or ask questions like "how much will it cost you to send people out and hire a cherry-picker to access that if something goes wrong?". Their more bean-counting oriented people then tend apply pressure as necessary to the artistic types to reach a compromise based on likelihood of failure, consequences (e.g. a dead fixture in a random layout is much less noticeable than one in a line or grid) and cost of dealing with it.General rules are that things like PSUs and primary control gear (computer etc.) must never, ever be located somewhere that is hard/expensive to get to, and where practical, any electronics that can be moved to an accessible location should be, even if it means using a lot more wire.There are also some design aspects to mitigate the effects of failures, e.g. interleaving stuff so a single PSU or data failure doesn't affect a big consecutive block, designing content that is less affected by a few failed fixtures etc. Obviously the practicality of this varies a lot depending on the nature if the installation.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 31, 2014, 10:00:12 am
content: Quote from: CBP on May 31, 2014, 09:38:07 amThis was a fairly short timescale for something on this scale, being installed in such a difficult location - I think it kicked off about last October, & install started early May, so about 6 months. The biggest problem is usually getting a definite "Go" from the end client to start manufacturing, as it often needs signoff from all sorts of different people, many of whom rarely appreciate leadtime issues. For stuff on this scale you also have things like signoff from structural engineers and the people in charge of the building. Leadtime on this was a particular issue as carbon fibre has fairly long cure times, and the manufacturer has finite autoclave capacity. They were working round the clock for at least a couple of weeks.QuoteI do try to insist on some burn-in time where possible, however this very often disappears due to other parts of the project running late. Failures after install can be costly, but sometimes preferable to not being able to finish in time for an opening.It can also be difficult, because as well as the actual fixtures, you also need all the cabling, PSUs etc. and things as simple as having the physical space to set it all up can be a major problem.One thing I always do at the design stage is test PSUs and anything that handles significant power at full load for at least day or two. PSUs are also never run at more than about 50-75% of their rating. Many PSU specs are somewhat optimistic - e.g. I once had a Traco DIN-rail unit that when running at 70%, the air coming out of the top hit 75 deg.C at 25 deg ambient - needless to say that didn't make it to the final install - we used a PULS unit that ran at about 40 deg.My general rule on heating is the finger test - if you can't hold your finger on it, it's too hot.Some things can be done at the design stage to reduce risk, e.g. designing an architecture which is at some level a number of identical parts which aren't dependent on others, so if one works, there is negligible risk that you will hit scaling issues.A good example of this is wireless setups - if the architecture is broadcast, with receive-only nodes, you know you won't hit bandwidth issues with larger numbers of nodes, however architectures like mesh networks or poll-reply & message forwarding can be very hard to fully test, and tend to have exponential failure modes as traffic increases. They can also be a complete bitch to faultfind.This is one reason I like one-way comms with no readback mechanism - there are far fewer things to go wrong, and for a light installation, it's obvious visually if something isn't working, unlike something like a sensor network, where you want to know the difference between "sensor not currently detecting anything" and "sensor broken or missing".Where you do need 2-way comms, I like using a time-slotted protocol so bandwidth is very well defined, and USB latency issues can be mimised (e.g. you send a "give me data" command, and each node replies in a timeslot defined by its ID, so you effectively get a single packet back with all the nodes' data) .For this install, there is one thing you do need to read back, which is an indication of when the SPI flash has completed its erase time, which can typically be 10-20 seconds. As this is only done occasionally, and manually, the way I handled this is for the controller to display a bargraph on the LEDs indicating erase progress - the person doing the content uploading sends an erase command, and then watches for this to complete before programming.The (much shorter) flash write times during programming are ensured by adding dummy bytes to the serial stream, so the baudrate guarantees sufficient write time.

author: all_repair
author_rank: Frequent Contributor
timestamp: May 31, 2014, 10:20:55 am
content: Impressive work of art !!! Do you have your name engraved somewhere at the base of the structure? So I can take a picture with myself if I happen to visit T2 airport, hopefully this few years (got no business to be there except for tour now). I like this better than the UFO

author: TheWelly888
author_rank: Frequent Contributor
timestamp: May 31, 2014, 10:47:59 am
content: Wonderful lights! Now that will make any flight delays a little more bearable. (I hope!)Imagine using incandescent grain of wheat bulbs for such a fitting!

author: Dago
author_rank: Frequent Contributor
timestamp: May 31, 2014, 11:14:32 am
content: One of the coolest things I've seen in a while. Awesome job!Must have taken a long time to solder each and every one of those LEDs by hand

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: May 31, 2014, 01:47:57 pm
content: Very beautiful, art that everyone would like!!Well done!!But, is there any sound from the installation, or is it quiet?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 31, 2014, 02:51:42 pm
content: Quote from: ErikTheNorwegian on May 31, 2014, 01:47:57 pmNo, but if you listen very carefully you can hear a slight buzz from the PSUs!

author: mariush
author_rank: Super Contributor
timestamp: May 31, 2014, 02:53:00 pm
content: Mike, I'm curious about something in the pictures you posted a couple of pages ago, in this post:https://www.eevblog.com/forum/projects/this-is-why-i%27ve-not-had-much-time-for-videos-recently/msg453911/#msg453911Don't beancounters argue with you about how you design these boards, or how much you quote them? For example, I would think if they see 5 x 3 pin connectors (picture in the middle), one going left, four going the other direction, maybe they would ask " why don't you use one 12-16 pin connector because it's cheaper than 4 x 3 pin connectors?" Wouldn't a connector with more pins be more resilient (soldered better and so on)Also, as long as we're at this subject, is there any particular reason why you arranged the connectors that way besides wires stacking or fitting nicely in small amount of space? Would it made better sense to put all the connectors to the edges so that wires wouldn't be on top of each other ?l

author: tom66
author_rank: Super Contributor
timestamp: May 31, 2014, 03:00:44 pm
content: Isn't the TLC5973 only rated for 21V standoff? How does that work on a 24V supply? Do you rely on the LED leakage being low enough for this not to be a problem?

author: SeanB
author_rank: Super Contributor
timestamp: May 31, 2014, 03:02:39 pm
content: I do not think they care. It likely was done as the boards would be smaller without the traces being routed to the edges, and as each then goes to a single module you can easily change just a module, a cable or whatever without having to undo and remove the other 4. The wiring stacks lower than the connector height in any case.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: May 31, 2014, 03:24:30 pm
content: I'm coming to LHR in a couple of weeks. Will I see this first hand? And Where?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 31, 2014, 04:04:24 pm
content: Quote from: mariush on May 31, 2014, 02:53:00 pmCost of parts like this is not an issue. There is one connector per strip so that each PCB can be tested easily prior to encapsulation. Also, the connectors need to pass through small holes when the encapsulated strip pair is fixed onto the carbon fibre arc. Holes in the carbon had to be minimised to avoid structural issues - the cable goes through a hole in the top, then another in the side - this is a rather fiddly operation and was tested on a wooden mockup to make sure it was possible before finalising the design.Cable management is very important here, and is why they are laid out like that (picture is a development unit so cables are a mess - they should fit neatly into the centre gap.) - the arc fits onto a bracket at the end of the support rod, and this has to slide in with no risk of cable damage. It also needs to be easy to connect/disconnect the incoming conector, while holding the 2m long arc, working on a cherry picker up to 12 metres high.I had to fight to make the centre joint area as big as it is, to accommodate the PCB and connectors. Connector size was a balance between small to minimise the overall size, robustness and being able to take wires of the required gauge for power.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 31, 2014, 04:07:37 pm
content: Quote from: tom66 on May 31, 2014, 03:00:44 pmLED Vf leakage is negligible - the worst that would happen is a tiny amount of light when off. The only time you need to worry about this is if there is significant capacitance or inductance, e.g. wires or very long tracks to the LEDs.

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: May 31, 2014, 05:12:19 pm
content: Quote from: mikeselectricstuff on May 30, 2014, 03:49:15 pmI wonder what that would be in Amps

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 31, 2014, 05:47:45 pm
content: Quote from: Mr Smiley on May 31, 2014, 05:12:19 pm5 PSUs, each 24V, 40A.If we ran all LEDs at 100% it would actually be about 20kw (but they wouldn't give us that much!). The content is way under 100%, and as a fall-back, the firmware in arc controller calculates the total LED power demanded and progressively scales back the brightness as required to keep current below a fixed limit without any sudden brightness changes.The PSU feeds are arranged so that you can light an area pretty brightly whilst keeping load reasonably well balanced across all 5 PSUs.These Puls PSUs are also rated to supply 50% overload for a few seconds - they actually have an MCU in there to manage this properly - if you use the overload capability it has a timeout, and a holdoff time after an allowed overload during which it will not allow a further overload, to keep the mid-term avarage power, and hence temperature within limits.

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: May 31, 2014, 05:56:43 pm
content: Many thanks Mike.Just one thing, is that 2 or 5

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 31, 2014, 06:31:18 pm
content: Quote from: Mr Smiley on May 31, 2014, 05:56:43 pm5, corrected

author: Unknown
author_rank: Unknown
timestamp: May 31, 2014, 07:53:13 pm
content: Hi, wow - truly stunning!How did you get into art installation work?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 31, 2014, 08:10:13 pm
content: Quote from: Ed.Kloonk on May 31, 2014, 03:24:30 pmYou need to be departing from Terminal 2. You won't miss it.

author: tom66
author_rank: Super Contributor
timestamp: May 31, 2014, 10:31:46 pm
content: I'd love to be involved in something like this.I was working on an installation a while ago with my university. We had a 17V, 22A PSU (so about 370W max.) In reality with all LEDs on it uses 170W, 50 x white LED 3.5W+resistor. But still about 10A so we had some thick bus-bar wiring to get minimal drop across the array.But then the artist/designer says only one LED lit at the time in most cases.So it feels a little over-engineered running 400mA through 30A twin-and-earth... but we do. Every 1/4 hour all the LEDs light up for about 30 seconds.How's the EMI work out for PWMing all those LEDs? I'm guessing since each driver is out of phase it works really well, and you see almost no ripple current? How much bulk decoupling did you end up putting along the light bars... did you need any at all?

author: amyk
author_rank: Super Contributor
timestamp: June 01, 2014, 12:38:00 am
content: Quote from: mikeselectricstuff on May 31, 2014, 05:47:45 pmThat's clever, sort of like dynamic contrast in LCDs.

author: tom66
author_rank: Super Contributor
timestamp: June 01, 2014, 01:08:18 am
content: It's used in plasma displays too.If a 50" plasma panel were to display full white it would use about 900W. Plasmas already use a lot of energy, that would be a tad too much! They take advantage of the fact that white has 1/3rd the energy per pixel as red, green or blue. So displaying white uses nearly the same power as displaying red, green or blue. Full white power can then be kept around 250~300W (and even less for modern panels.)

author: HP-ILnerd
author_rank: Frequent Contributor
timestamp: June 01, 2014, 06:33:09 am
content: Bloody hell, Mike. That's gorgeous!Throw in another vote from me for an AmpHour ep where you talk about this.

author: BillyD
author_rank: Regular Contributor
timestamp: June 01, 2014, 12:34:02 pm
content: Superb! Well done.

author: robrenz
author_rank: Super Contributor
timestamp: June 02, 2014, 01:34:58 pm
content: Very very impressive Mike! Amazing work

author: aargee
author_rank: Frequent Contributor
timestamp: June 03, 2014, 10:28:10 am
content: Very nice, Mike.The mathematic algorithms to light up in sequence and patterns amaze me.

author: Kjelt
author_rank: Super Contributor
timestamp: June 03, 2014, 10:46:25 am
content: Beautifull, must be a joy to create such work

author: echen1024
author_rank: Super Contributor
timestamp: June 06, 2014, 03:28:55 am
content: Bloody gorgeous, as you brits would say it.

author: tja
author_rank: Contributor
timestamp: June 10, 2014, 12:29:36 pm
content: Fantastic work Mike - very impressive, and I really apprecaite you being so open about the details, most helpful to amateurs like myself.I don't suppose you'd like to give us a clue about the budget for this would you? Well into low 6 figures (GBP) I'd guess ...

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 10, 2014, 01:30:03 pm
content: Quote from: tja on June 10, 2014, 12:29:36 pmNearer towards the mid 6 figures, a lot of which was for carbon fibre, and a lot of install costs. I doubt that all the electronics came to more than 10%

author: madshaman
author_rank: Frequent Contributor
timestamp: June 10, 2014, 02:27:18 pm
content: Totally sick!!!Well done.

author: N TYPE
author_rank: Regular Contributor
timestamp: June 10, 2014, 03:06:30 pm
content: Hey I really like the light piece, could you please upload the arduino sketch; also what shield did you need to use?Thanks

author: lapm
author_rank: Frequent Contributor
timestamp: June 10, 2014, 03:51:23 pm
content: That installation is just beautiful..

author: lapm
author_rank: Frequent Contributor
timestamp: June 10, 2014, 04:10:15 pm
content: Quote from: Dago on May 31, 2014, 11:14:32 amI believe Mike has pick-and-place machine for this sort of things...

author: SeanB
author_rank: Super Contributor
timestamp: June 10, 2014, 04:57:16 pm
content: I think he is upgrading to a new one, and selling the old one.......

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 10, 2014, 05:08:51 pm
content: Quote from: SeanB on June 10, 2014, 04:57:16 pmI did the control & splitters on mine - the 1 metre LED boards were done by someone with a much bigger & faster one.

author: SeanB
author_rank: Super Contributor
timestamp: June 10, 2014, 05:13:04 pm
content: Yes, you might need a bigger garage soon, or give up and use the whole house and live in the garage.

author: arteitle
author_rank: Newbie
timestamp: June 19, 2014, 01:47:09 pm
content: Quote from: mikeselectricstuff on May 30, 2014, 06:03:49 pmHi Mike, I'm a long-time fan. I happened upon this thread while searching for discussion on the TLC5973, since I'm planning on using it in a project. Rather than bit-banging the data line, I like your idea of using an SPI port to talk to it. Does your sneaky trick involve using each byte out of the SPI to transmit two bits to the TLC5973? It looks like you could send a zero as "1000" (assuming MSB first) and a one as "1010". Am I close?Thanks,Aaron T.

author: bookaboo
author_rank: Frequent Contributor
timestamp: June 19, 2014, 02:44:14 pm
content: A simply stunning project, well done to all involved.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 19, 2014, 03:43:06 pm
content: Quote from: arteitle on June 19, 2014, 01:47:09 pmMore efficient than that - you AND the data out and the clock, so you have 2 SPI bit times per TLC5973 bit. Using a 74HCT08 also gives you a 3.3v to 5V level translator.There is an additional fiddle to get a whole number of TLC5973 words, including the latch gaps, into a whole number of 32 bit SPI words, making use of the fairly wide timing tolerance (adding occasional SPI 'idle' bits) and a big lookup table.If you're not too concerned about speed then you can use a significantly simpler scheme.Some fiddliness using SPI comes from having to have the 3.5 to 5.5 Tcycle end-of-sequence gap, as it's a pain if this is can't be aligned with SPI words.

author: saturation
author_rank: Super Contributor
timestamp: June 27, 2014, 06:49:50 pm
content: Great work.Kudos.

author: jmole
author_rank: Regular Contributor
timestamp: June 29, 2014, 09:27:35 pm
content: Just met Dominic Harris in Basel at Deisgn Miami/Basel last week, and had a nice talk about the infrastructure/architecture behind the piece. Had no idea you were involved! Great work. Was this a consulting gig, or do you work with him regularly?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 29, 2014, 09:35:36 pm
content: Quote from: jmole on June 29, 2014, 09:27:35 pmI do quite a lot of stuff with him, amongst others. He was actually my first contact in the wacky world of art/architecture stuff when he was with Jason Bruges

author: jmole
author_rank: Regular Contributor
timestamp: June 29, 2014, 09:44:54 pm
content: Quote from: mikeselectricstuff on June 29, 2014, 09:35:36 pmI take it you're based in London then? Quite a scene there as far as interactive art goes, and lots of friends in that area that I need to visit at some point. Would love to come say hello whenever I make the trip.

author: jmole
author_rank: Regular Contributor
timestamp: June 29, 2014, 09:54:43 pm
content: BTW, this is why I was in Basel; my first large scale interactive installation: