LED Labs

Yes, I know this was long ago, but I finally edited the images from this UnScruz 2024, and they are PARTICULARLY lovely. Please share!

Mariposa @ UnScruz 2024 44 new items · Album by Christopher Schardt

My new LED piece is a giant prayer wheel, like you find on the side of the trail in Nepal. It spins when a human gets curious enough to try spinning it. Then its LEDs change color quickly enough to make use of Persistence of Vision to create images.

Here are the first images of its first night spinning. It will be at Burning Man this year, somewhere in deep playa. :-)
https://photos.app.goo.gl/uhAT791QhoG2qqRn7

Ilya, Valeria Choupina, and I brought Mesmer to the Bard AI holiday party last night. It was a hoot!

Mesmer @ Bard AI Holiday Party 29 new items · Album by Christopher Schardt

An LEDLab user just asked me whether there is a count of LEDs that causes problem with LEDLab and PixelPusher. I ended up writing a bit a of a treatise on LED display performance. I thought that some of you might find it useful:

My pieces, Firmament and Nova each have 21,600 LEDs. Missive has 20,736. All work just fine.

There ARE potential problems as LED count increases, though:
1) a high count of UDP packets can slow down communication
2) frame rate can be slowed by calculating more pixel values

These slow downs come on gradually though. You'll definitely notice this before the problems are bad.

Here's something I only learned recently: For my pieces, the biggest factor slowing down frame rate is the extent to which I'm exerting the PixelPushers. They report back to LED Lab how fast they'd like to receive packets. They definitely demand a slower rate (which slows down LED Lab) when they are fully-loaded - that is - you're using close to 480 LEDs/output on all 8 outputs. So using more PixelPushers with fewer LEDs each CAN speed things up. This is particularly true with slower-responding LED chips like WS2801.

Another thing I've noticed is that using a lousy router can slow things down. Worse, it can cause jittery display. If you can use hard-wired connections (no WiFi), you'll definitely see better performance. Apple sells a new USB/Lightning adapter that has a socket into which you can inject power. You can then plug a USB/Ethernet adapter into that. It's the bomb!

If you need WiFi, definitely use the 5GHz band. I highly recommend the Xiaomi Mini router. Also, know that when you've got 1000s of people attending your piece, their smartphones can KILL WiFi response. This is because they're all pinging every WiFi network they can find, all the time apparently. Best to have a router on which you can turn off SSID transmission. (Your iPad will remember the network if you've connected to it before you hide SSID.)

Lastly, use as beefy an iPad as you can - iPad Air 2 or better. I've noticed that the iPad Pro is noticeably faster.

I gave a talk entitled "LED Art Supplies for the Masses" at the GlowCon conference/party last weekend. In it, shared my thoughts about the various LED products, LED chips, LED controllers, and LED Lab. If you're interested, here are my notes from that talk: http://schardt.org/ledlabs/GlowCon2016.pdf

schardt.org