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#203457
Hello all,

I'm currently in the planning stages of designing a large scale LED project for an ambitious startup we have in the works. Without giving up too many details of it right now, I'll have on the scale of approximately 1,800 36"x36" hexagonal shaped
'tiles' that will fit about 3 meters of addressable RGB LED strips inside, each tile. I'm leaning towards the 60 LEDs/meter options. This would yield roughly 324,000 LEDs. Bare in mind that each tile of about 180 LEDs could act as a controllable node, so my main controller could just tell the tile to do a red chasing pattern, instead of telling a specific LED on the tile to do something.

For a small scale test, I think it would be relatively easy to get the addressable LED strips and control them with the FadeCandy NeoPixel driver. This driver states it can control 512 LEDs, so 1 controller will be good for 2 of my tiles, total of 360 LEDs.

On a small scale, I can of course drive this with an Arduino or other controller, and fairly easily configure these to make the sequences I need for a fancy light show. The issue is when I connect 1,800 tiles, how do you manage the configuration of each and every LED driver and multiple Arduinos/Pis, so you can accurately turn on 1 tile at a time in a certain location on the grid? Maybe I need to look at a completely different options than the FadeCandy server?

So, with that quick intro, a few questions:
1. Do you think it is feasible to utilize about 900 FadeCandy drivers in one large scale project? If absolutely not, are there any hobby or even professional boards out there one could suggest?
2. How would you recommend configuring 1,800 tiles so they are sequenced correctly? A dumb way would be to simply label each controller with a number and ALWAYS place it next to its neighbor, and never mix them up. This would be VERY cumbersome.
3. Oh, and BTW, I'll need a powerful fan in each tile, so keep that in mind as well, haha. Any thoughts on how to combine the two tasks? Fan's specs are still TBD as far as power requirements. We need to lock down some CFD analysis to determine required airflows.

Please feel free to blast me with ideas/comments/questions/criticism. Thanks in advance!
#203484
A few ideas/issues:
- How rapidly do you want to have the tiles change from one pattern to another? This will affect the physical layer.
- Do you want the changes to be synchronized? If so, don't forget the time it will take a signal to get from one end to the other
- Power - each tile will need about 50W of power (180 RGB LEDs, 50mA each at 5V, plus the electronics). At 1M RGB LED strip per tile, you really don't want to try pushing 5V at 10A per too far or the voltage drop will cause big problems. You can always use a buck converter per tile and pass 24 or 48V around, but even at 48V, you will need a power suppy (and fan, fusing, enclosure, etc) for every 10 or so tiles. At these currents, don't forget about proper protection (fusing on supply inputs and outputs, proper connectors and wiring, etc)
- Data - You didn't mention the organization of the 1800 tiles, but you need to keep the length limits for various data schemes in mind. Putting the controller in the center (or using a tree of controllers) may make this easier. Likewise, there are limits on how many nodes on a cable. I'd probably do this with RS485; for full video, gigabit ethernet comes to mind.
- Commissioning - various schemes come to mind; each tile could have an "in" and "out" signal that gets shifted through the line and once say 255 addresses get shifted, each could latch in its corresponding address. Alternatively, point a camera at the tiles, have each turn on in turn, and have the camera map where it is
- Redundancy/failsafe - what happens if a tile dies - will it pass whatever signal through or will you lose all nodes downstream of it. If you have a data stream to each tile, you may want to monitor temperature, supply voltage and current, etc. to attempt to catch issues before they get too bad.
- Cost - Obviously not cheap; you will need the enclosure, LED strip, PCB (I would make a custom board for the tile), power supply, fan, mounting hardware, wiring, etc. times 1800.

You may want to get in touch with Mike Harrison over at http://www.whitewing.co.uk/ (AKA Mike's Eletcric Stuff) as he does this kind of large-scale LED designs and installation
/mike
#203489
Thank you for the thorough evaluation and thoughts on this. I'm aware of the power and fusing requirements, as well as data length limits and costs. I definitely appreciate the link to Mike's website. That may be exactly who I need to chat with to help really get this rolling. We are definitely not skimping on costs. Very quick rough numbers will put each tile at about $100 (without direct sourcing and volume discounts). So yes, just in the LED portion a full setup would be nearly $180,000. And I haven't even costed in the blower fans yet...