555 Cartoons

Drehkino is a Turntable Cinema that plays short (50 frames) looping animations from specially printed, disks, and is housed in a wooden frame similar to a record player. The paper disks are the frames of animation and an optical rotary encoder pattern, that pattern is picked up by a infrared pair scavenged from an old mouse. The signal is then passed onto a 555 timer configured as a Schmitt trigger that (indirectly) drives the led strobe light creating animation that is synced to the speed of the turn table.

That sounds all good and well, but it must be a big pain to split up an animation and calculate each frame’s position etc, well that is covered too by a couple scripts. Movie clips are sent though virtualdub to select what 50 frames you want, then are exported to individual images, an sh script then takes over and gawk is used to manipulate the data and create an ImageMagick (“CONVSCRIPT”) file. After you do the script dance you are left with a perfectly spaced wheel with encoder ready to print on standard paper in a PDF format.

Software and schematics included, with future improvements already in the works and its nifty, so its worth a check. This is an interesting take on the old zoetrope design.

10 thoughts on “555 Cartoons

  1. Wow, 50 whole frames? What kind of video lends itself to a short clip of the same thing over and over?
    I do like it for the re-purposing of the optical encoder, along with the simple timer linked to it to drive the LEDs.
    Interesting electronics, but not interesting implementation IMO.

  2. Correction: It’s not a 555 set up as a Schmitt-Trigger (which can be done), it’s a a 555 set up in One Shot mode (aka Monostable) and he’s using a Schmitt-Trigger Inverter to add hysteresis to the pulse train coming from the phototransistor. Nice project!

  3. I did something like this about 5 years ago, but I used a small piece of sheet metal that pressed a very small mechanical switch (I think it was a pull from a cd-rom drive or something like that) with each frame; amazingly the result looked quite good even when the loop was only about 12 frames long.

  4. I can see purpose here, think of the holiday projectors, use a larger LED source, some gating to keep light spill to a minimum, then some lenses. 50 Frames of Santa Claus Saying HO HO HO is plenty.

  5. Couldn’t you print this as a continuous spiral, only one layer at a time of which passed through the read head?

    you should be able to roll thousands of frames through it that way as long as you’re willing to cut and splice the frames over and over again.

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