16-Segment Roman Numeral Clock

You’re certainly familiar with the Arabic numbering system, i.e. 1,2,3,4, etc. for your counting needs. If, however, you look at many buildings, or text that’s simply meant to appear grandiose, you’ll also encounter Roman numerals with X for 10, V for 5, and a series of I characters to add or subtract 1 as needed. It does look nice, but try doing calculus with such a system, and you'll soon see why we switched.

These numerals can also be seen on the face of many analog clocks, but not so much the digital variant. Mark Wilson, though, came up with a way to tell the time using this ancient system, not with a fancy OLED display, but with a 4-digit, 16-segment panel. The first three digits are used to show the hour with I, V, and X characters. The last digit reveals the minute to the nearest 5 minute interval by displaying miniature Is and Vs on the top and bottom depending on if the time is closer to a 5 or 0. The clock can also display Arabic numbers, pseudo “Predator” characters, and even random 4-letter words.

The device runs on an Arduino Nano clone, along with a DS3231 RTC unit for timekeeping, and a pair of buttons are implemented as a user interface. The housing is laser-cut with the inner segments divided into two pieces each, cleverly designed for efficient material usage.