8×16 ping-pong ball LED matrix display

Exapod built a 8×16 ping-pong ball LED matrix display. The ping-pong balls are used as diffusers for green LEDs. Two MAX7219 8bit serial LED drivers control the lights. A PIC18F2553 drives the MAX chips with text received over a Bluetooth module.

I finally finished my 8×16 ping pong ball matrix display, soldering all the boards, the leds, the wires and gluing the ball took me a lot of time. It uses a pic18f2553 to control two max7219, the string to display is sent via bluetooth.

Check out a video of it in action below.

Via the forum.

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  1. Not to be all Negative Nancy, but: ping-pong balls are incredibly, incredibly flammable. I had designed a kit that used ping-pong balls as LED diffusers for a nightlight, then I saw a demo of a flaming ping-pong ball at dorkbot. They’re sort of hard to light when intact, but as soon as you make a sharp corner by cutting them, an open flame catches really quickly.

    Just something to keep in mind when installing an otherwise-awesome piece like this one. Don’t put it along critical fire-exit paths, because it will be its own little inferno in case of a fire.

    1. They’re only dangerous because they’re an unexpected hazard. There’s lots of stuff that’s that flammable (well, okay, only a few, but, y’know); it’s just a matter of making sure that you factor in the hazard. One nice thing about nitrocellulose is that it burns off really fast and really cleanly, so you probably just need to give it some room to burn out before it catches anything else on fire.

      Neat project, btw. I just got a chance to look at it closely enough to appreciate the actual construction technique. I’m now seriously considering hacking together something similar, but with a piece of frosted glass for diffusion (which, with a toddler who likes to throw stuff, is probably actually more dangerous).

  2. Back in the late 70’s we made home-made smoke bombs out of ping pong balls. cut them into fine shreds withh box cutters, put them in a match box, light them, then close the box…
    The smouldering remnants produced a thick white smoke that looked cool to us.

    It was only later we discovered the smoke is quite dangerous. Toxic, in fact.

    1. But I remember the smoke didn’t smell unpleasant, well we are all still alive… we used aluminum foil and scissors.

  3. Try telling that to the Principal of Blackburn South High School in 1978… afte a 20+ ball effort [in aluminium foil, as we Aussies call it] drifted down the school hall. Classes disrupted, fire brigade called, lucky not to get expelled on that one.

    Not that I was INVOLVED. Oh no, officer, I skipped school that day – luckiest decision I ever made.

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