June 25th, 2021—
Way back in the 13th century, an order of monks known as the Cistercians created a unique numbering system that used a series figures and rotations to represent numbers up to 9,999 in just a single character. Because these numerals are so great in compact displays, using them in a dot matrix to show the current date and time was a no-brainer for danjovic.
For the aptly named MonKlock, Danjovic combined a DS3231 real-time clock with an Arduino Nano to keep track of the current time, plus a large 4″ 5×7 LED matrix. All of these components were placed onto a custom PCB, along with two buttons that cycle between various modes and the time, day, month, and year. Finally, he made a wooden base that props up the PCB vertically and provides a convenient path to run the USB cable.
In order to translate a given decimal number into a Cistercian numeral, danjovic designed a custom font that maps the figure to an array of pixels. When it’s time to display a number, the required numerals are added on top of each other using some simple arithmetic, and then the final result is sent to the LED matrix.
As seen in Danjovic’s video below, the clock looks really cool while powered on, and the additional functionality from the two buttons adds even more fun. Even though it can take a while to learn what each numeral represents, this project is still a great showcase of using clever math to fit dense information in a small space.