Driving an 8-digit split flap display

[Markus] got his hands on a split-flap display and built a controller for it. These sometimes can be found on really old alarm clocks, but [Markus] was a lucky-duck and managed to acquire this large 8-digit display which previously made its home in a railroad station. They work like a Rolodex, mounting flaps around a cylinder for a full alpha-numeric font set.

A PIC 12F683 was selected to control the display, using optoisolation to separate the 42V display motors from the driver circuit. From the video after the break we think he did a wonderful job of getting this working. It only takes six I/O pins to control and the sound and look of the digits scrolling leaves us quite jealous.

So what’s he got in store for it? The first thing he did was use it to count down to the New Year.

28 thoughts on “Driving an 8-digit split flap display

  1. Seems like it wouldn’t take too much effort to make a design for this kind of display using a laser cutter or CNC machine. The mechanism is simple, everything except for the motors and sensors could be created from laser-cut wood. I’m sure a kit for this kind of display would have high demand.

    Someone with access to a laser cutter, get on it quick!

  2. Great.. now I have to go find an old railstation and do some reallocation of property in order to feed my want of one of these. I wonder what the duty cycle on the mechanics are, as I would probably just have it flip around randomly for the fun of it.

  3. You can make your own ‘Lost at Home’ game where you have to push a button every 108 minutes or else a bunch of red hieroglyphics appear.

  4. I’ve waited months for something like this!

    I want to use something like this for a portable MP3 player, automobile receiver, or Hi-Fi set fashioned like something out of the 1960s or 1970s. Move over steampunk, there’s a new retro modding scene.

  5. Cool.. yea. I was also wonder what those things call…

    But yup, it is too noisy to use as a clock.

    Now it would be even cooler if it is the dot matrix version (often seen on older buses)

  6. they used them for “digital” clocks for many years in the home (obviously smaller) though the seconds were usually on a wheel that just rotated from 00 – 59

  7. I’m sure there are many available on ebay and such sites, since most stationdisplays and other public displays are going digital in droves the last years

  8. This made me think of using it in the back of my car for either telling people off “instead of an electronic led version” or some weird James Bond license thing but I don’t think it would work.

  9. > I wonder how he knows where zero is, if the display is reset, does he manually have to reset zero?

    There are two reflective IR-sensors: One for counting the characters and one for finding “zero” position.

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