Print an Arduino-powered color mechanical television • Hacker News Board

Re: Print an Arduino-powered color mechanical television

#11

Post by Animats » Sun, May 29, 2022, 7:37 AM UTC

tyingq wrote: post #4

guerrilla wrote: post #2

Hmmm, it's tiny... but what about a bigger matrix of LEDs that can be moved around just a little bit. The idea I guess is time-multiplexing lights in space... So if you have a big board with a grid of LEDs and shake it around a bit, you can do the same thing but with less movement and more lights... You get more pixels for the same number of lights. (Hopefully someone can visualize what I mean.)

There are little toy fans with 8 or so leds on the blades that do this...show a word while the fan spins.

There used to be cheap LED wand displays you could wave in the air to display messages. Once popular with ravers.[1]

[1] http://www.houseofrave.com/skyliner_message_writer.html

Re: Print an Arduino-powered color mechanical television

#12

Post by rkagerer » Sun, May 29, 2022, 9:47 AM UTC

https://youtu.be/LmISP_fAAws?t=15

I find the images gorgeous and could watch this for longer. Anyone know if there's more footage anywhere?

Also how big could one theoretically / practically scale this up? How big a wheel would you need for a public display?

Re: Print an Arduino-powered color mechanical television

#13

Post by UncleSlacky » Sun, May 29, 2022, 3:56 PM UTC

This reminds me of the recovery of original Baird recordings (made on phonograph-style discs) which couldn't be played back at the time, but modern technology came to the rescue:

http://www.tvdawn.com

Re: Print an Arduino-powered color mechanical television

#14

Post by linker3000 » Sun, May 29, 2022, 4:12 PM UTC

There was a project in the 1980s in one of the electronics mags to make a mechanical TV. I didn't build a unit, but the bit I remember was the need to sacrifice a 12" LP for the disc and drilling a spiral of holes in it.

Re: Print an Arduino-powered color mechanical television

#15

Post by zimpenfish » Sun, May 29, 2022, 5:49 PM UTC

guerrilla wrote: post #2

Hmmm, it's tiny... but what about a bigger matrix of LEDs that can be moved around just a little bit. The idea I guess is time-multiplexing lights in space... So if you have a big board with a grid of LEDs and shake it around a bit, you can do the same thing but with less movement and more lights... You get more pixels for the same number of lights. (Hopefully someone can visualize what I mean.)

I worked for a company (2009-10) that made big spinny ones for outdoor advertising (they got a few deployed in the UK) and were working on a 8'x5' billboard-style one which had 8 huge rotors, each with 4 arms, coated in (of the time huge) LEDs.

When it span up, it sounded like a steam-powered 747 trying to take off.

Thankfully (because the potential for catastrophic disintegration was huge) the company went bust before any of these got deployed anywhere near the public.

Re: Print an Arduino-powered color mechanical television

#16

Post by mLuby » Mon, May 30, 2022, 4:10 AM UTC

Any reason a belt with holes couldn't replace the disk with holes for a more compact and rectangular viewing surface? Should be easy enough to test with a belt sander.

The closest thing from the time was mirror drums but those don't sound too similar, and they had mirrors for some reason.