Earlier this year we covered an automated perpetual calendar, which used three ring gears to align the date, month, and day of the week with a viewing window. After building one of these devices, Wolfspaw was inspired to put a new “spin” on things by combining it with a linear Cryptic Calendar, featuring digits that only make sense in the viewing window.

The resulting project looks like a few rings inscribed with alien symbols, until each is rotated in place. This frames the numerical date, as well as abbreviated month and day so that they can be read.

Everything runs on an Arduino Nano and an RTC module, while 28BYJ-48 stepper motors with drivers to turn the trio of rings.

Full details can be found in Wolfspaw’s write-up!