LED Control - en masse

Discussion in 'Hobby Engineering' started by underskore, Dec 15, 2019.

  1. underskore

    underskore Member

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    Hi - I've just had a friend start asking me questions about how he can make/control a certain sort of (mainly lighting driven) AV rig that he dreams of showcasing at mainly bush doofs (but as a holy grail destination; Vidid in Sydney).

    With an idea of something along the lines of a <snip> being the inspiration for what he has in mind it's a bit too full on for me to have any solid ideas for him so I'm coming here (at least) looking for any kind of advice to help me push him in the right direction or (at best) a referral to the right of easy to follow/copy projects to let me show him how this problem is already fully solved and just a matter of implementation requiring only minimal hard work.

    My thought's were initially that he should start by looking into DIY MIDI control (or christmas setups) with arduino/pi but I eventually remembered about something called DMX for lighting (and am just telling him to that that to this google list)... that's the extent of my initial advice for him.

    So the question is - with this idea of some sort of <snip> (fully sick lighting thing) being the goal - do you have aany droplets of advice or relevant thoughts to drop on me to hand to him?
    • wiring diagrams/control-structures for bulk LED control
    • code snippets for MIDI/DMX control
    • supersonic xmas light projects
    Please share anything you've got that might help me steer this idea of mates into fruition.
     
    Last edited: Dec 17, 2019
  2. theSeekerr

    theSeekerr Member

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    DMX512 is fairly straightforward - at a physical level it's usually just RS-485 over 3 pins of a 5-pin XLR connector.

    The protocol, too, is pretty straightforward - it basically just spams out 512 8-bit values, each of which is a 0-255 control signal to be interpreted by a DMX slave. Traditionally each channel was interpreted by a dimmer as the intensity of a light fixture, but these days it's co-opted for everything that needs controlling including motorised and RGB fixtures - a pan-tilt fixture with RGB, iris, gobo, gobo rotation and a few other gizmos will consume 13+ DMX channels all by itself.

    So in terms of the physical implementation all you need is a vaguely modern microcontroller with a UART and an RS-485 driver like MAX485.

    On the software side, I'd be looking into the DMX-over-IP technologies, ArtNet and sACN. That will lead you to Open Lighting Architecture (OLA) which will prove a mighty handy toolkit for building ethernet / WiFi to DMX gateways: https://www.openlighting.org/ola/
     
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  3. _zak

    _zak Member

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    One of the biggest issues with big LED installations is getting power to them - the low voltage means that you're looking at high currents and large power losses in the cables. The voltage drop means the LEDs won't look right, particularly if they're RGB LEDs and/or further along in the string. On a similar note, cables and connectors become critical at the sorts of currents you'll likely be working with.

    In terms of resources, I'd definitely recommend Mike Harrison's stuff (particularly his talk from this year's Hackaday Superconference). His main area of work is producing lighting displays for big clients, and there's heaps of useful information in his videos.
     
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  4. OP
    OP
    underskore

    underskore Member

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    thanks _zak & theSeekerr - that's some good info to help get me & my mate started on understanding what he might be getting into.
     
  5. aXis

    aXis Member

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    I've been helping a mate with this stuff for a few years as part of Christmas light installations. The technology is booming and you can get some cheap gear off ebay / aliexpress.

    For the software, there are options like LightFactory and Madrix. My mate has Madrix and it's particularly good at getting great glowing, flowing special effects with minimal effort. It may cost $1000ish for a decent pixel count but it really does a great job. There are also some free / open source options, but results vary.

    For the lights, the easiest thing to do is to buy LED strips that support one of the many "pixel" protocols:
    - NeoPixels - eg https://learn.adafruit.com/adafruit-neopixel-uberguide/neopixel-strips
    - WS2812 / WS2812b / WS2813 - eg https://www.aliexpress.com/popular/ws2812b-string.html or https://www.suntechleds.com/info/what-is-the-difference-ws2811-vs-ws2812b-vs-ws-34944590.html

    You would then also need some sort of interface controller between the LED string and the PC. I recon the smartest option is to use an Artnet (ethernet) to SPI/TTL controller. Madrix will happily talk the Artnet protocol via either wired or wireless ethernet, and the converter sends out the appropriate WS2812 pixel protocol.
    Eg: https://www.aliexpress.com/item/4000189878839.html or https://www.aliexpress.com/item/32992045127.html

    For wiring it all up, you will need some hefty 5V or 12V switchmode power supplies, weatherproof connectors between the strings, and also extra DC cabling and power injectors between the strings every 3 to 5m to keep the brightness up.
     
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  6. OP
    OP
    underskore

    underskore Member

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    Even more great info, thanks aXis.
    Let's say that I'm interested in rolling my own adressable LED strip equivalent (as in to use brighter, sparser setups that the off the shelf ones don't meet the needs of) that can be driven by the same control system being used for the standard strips. Any tips?

    I know I'm getting lazy now and that that question has probably been answered many times but while I've got the attention of a few people much more knowledgeable than I, I might as well ask.
     
  7. aXis

    aXis Member

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    My mate had some larger arrays of 4 - 6 LED's, and each array acted as one pixel. They had about 10-15cm of wire between each module in a string, but you could cut and reconnect them.

    Just trying to find something similar on aliexpress. Just double check the protocol compatability before purchase.

    Update - I searched for "LED pixel", not quite what I used before but similar in principle:
    https://www.aliexpress.com/item/32663025026.html
    https://www.aliexpress.com/item/32799800218.html
    https://www.aliexpress.com/item/32799664404.html
    https://www.aliexpress.com/item/32811491088.html

    Update 2 - here, found them:
    https://www.aliexpress.com/item/32650721090.html
     
    Last edited: Dec 17, 2019
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  8. OP
    OP
    underskore

    underskore Member

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    Sounds like what I believe he needs is most likely all off the shelf.

    Thanks for the quick answer
     
  9. MUTMAN

    MUTMAN Member

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    copy this, get public liability insurance :)
     
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  10. dakiller

    dakiller (Oscillating & Impeding)

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    Check out mikeselectricstuff YouTube channel. His day job is to design custom large scale lighting and LED displays, he puts up videos on interesting bits he works on and things he invents to overcome issues when you scale up big. None of it is a straightforward how to, but for anyone interested in electronics it is all a good watch.
     
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  11. JSmithDTV

    JSmithDTV Member

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    Well that'll be fckin trippy. :thumbup:


    JSmith
     
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  12. dirtyd

    dirtyd Member

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    There's also SK6812 addressable LEDs, they're a knock off of the 2812 or the other way around, but they support higher frequency, and you can get mini's.
     
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  13. ShadowBurger

    ShadowBurger Member

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    Sounds like a fun project. I'm looking at doing something similar but on a smaller scale; a fairly dense 'netting' of ws2812b LED strips to hang up under the roof of my alfresco / BBQ area thing. It's about 8m x 3m. Warm-white light would be the go but I want the ability to build my own controller and have a play with lighting effects and whatnot. I've worked out the power will be the tricky thing for so many LEDs but an old OEM PC PSU will put out plenty of amps, just the wiring will be a pain
     
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  14. PabloEscobar

    PabloEscobar Member

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    I do computer controlled electric lights, using WS28xx and Xlights

    https://auschristmaslighting.com/threads/auschristmaslighting-101-manual.1889/

    Sign up and read that.

    For me, coming from IP... It took a while to grok DMX as far as universe boundaries and things go, especially as the numbers get pretty astronomical (keeping in mind that a single pixel is 3 DMX "channels")

    https://github.com/Aircoookie/WLED
    Is a super cool project for ESP78266's and wifi, can can accept E1.31 data. (Essentially DMX over IP)
     
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  15. OP
    OP
    underskore

    underskore Member

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    dirtyd I'm not sure if he'll need superfast response times for this (potential) project but it's good to know that (compatible?) options exist.

    ShadowBurger ill keep that PSU idea in mind

    PabloEscobar it might take me some time to digest the info you've linked but it looks like a motherload of relevant info
     
  16. PabloEscobar

    PabloEscobar Member

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    In many cases, its not the output of the PSU that is limiting, but the voltage drop down long strings of LED's

    PabloEscobar it might take me some time to digest the info you've linked but it looks like a motherload of relevant info[/QUOTE]

    I read it, didn't really understand a lot of it... so just went ahead and bought a bunch'O'shit off aliexpress. and when it arrived had a play.
    Then I read it again, and it made MUCH more sense.

    The community there is REALLY good, see if you can find someone with a Pixel Xmas Lights setup locally, and rock up and have a yarn with them. Nerds love to talk to other nerds about their hobbies.
     
  17. nic55

    nic55 Member

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    I use various WS2812/WS28111 lights from ali/ebay, hook them up to a NodeMCU flashed with WLED (https://github.com/Aircoookie/WLED) which supports E1.31 mode (DMX over IP). Then on a PC use Jinx!, Lightjams or x-lights to control them depending on what I'm doing.

    You can get a strip of 300 lights hooked up and controlled by a computer for under 40 bucks.
    Just keep adding lights and NodeMCU boards till you've got what you need.

    Here's a small clip of 88 12mm WS2811 LED's and a WS2812 pixel strip from when I was messing around with some sound reactive code. I think I was running this Arduino sketch https://github.com/atuline/FastLED-Demos/tree/master/soundmems_demo

     
    Last edited: Dec 19, 2019
  18. Pugs

    Pugs Member

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    Former lighting guy here... dmx is the biz.. lots of programs and dongles you can use... also lots of different boards/ power supplied for led strips..
     
  19. PabloEscobar

    PabloEscobar Member

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    Is DMX really the Biz, It seems rather antiquated?
     
  20. Pugs

    Pugs Member

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    Why what else would you use??
     

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