Panaplex "Nixie" Wristwatch
Nixie tubes are certainly interesting, emitting a beautiful warm glow. If, however, you’re going to use them in the confines of a wristwatch, they soon become unwieldy.
Another watch option, as shown here by Reddtior “Dycus,” is to use a device called a Panaplex display. These use the same sort of neon gas discharge as their Nixie cousins, but instead of using discreet cathodes for each type of character, the display is split up into a 7-segment arrangement.
This would presumably save a ton of space, and of course make for a watch that’s even less common than a normal Nixie model.
Overall control of the watch is accomplished via an ATmega328 microcontroller, and the next iteration will use an STM32L072 chip. Timing is taken care of by a temperature-compensated 32kHz crystal, which actually has glass window for viewing its internals. Naturally it was arranged on the watch for easy viewing.
The unit is set up to flash hours first, then minutes on its two characters, and also features and orange LED as an AM/PM indicator. In order to more easily make it waterproof, control buttons were replaced with a capacitive touch sensor on a flexible PCB section, which can be arranged behind the watch's glass.
It’s a clever design so far, and one that should look brilliant once it’s finished and wrist-mounted! Visit the watch reddit post to learn more.