It’s not pleasant thinking about one’s mortality, but that’s the point of this clock design: perspective. To make one aware of the passage of time and how precious each minute is.

Use an online calculator (some links below) to gauge your life expectancy, then plug that date into our code for this clock project. You’ll get a running count of how many minutes you have left. Or you can pick another event with a date of your choosing…the return of Halley’s comet (28 July 2061), a predicted date for the technological singularity (2045 according to Ray Kurzweil), a favorite future moment from science fiction, you name it.

As you look at the clock, remember that you are never getting those minutes back. Stop watching internet cat videos and make the most of them!

Here’s a few links to life expectancy calculators that can provide a final date. If one’s not working (or you don’t like their prediction), try the next:

• The Death Clock
• Death Timer
• Find Your Fate Death Clock

Parts and Tools

• Adafruit Pro Trinket, either the 5V or 3V version will work, whichever is in stock (with your own enclosure, the code can also work with most ATmega 328P-based microcontrollers such as an Arduino Uno…but NOT 32u4-based boards like the Arduino Leonardo or Adafruit Feather 32u4, nor ATtiny-based boards. The code relies on hardware-specific features.)
• DS3231 Precision RTC Breakout (or other DS3231 realtime clock breakout board, such as the MaceTech ChronoDot — again, will need your own enclosure)
• CR1220 Lithium coin cell battery for RTC. If you can pick this up locally at a nearby drugstore or Radio Shack, do that! This may slow down your shipment otherwise, due to safety regulations with batteries.
• 2 (two) 0.56" 4-digit 7-segment LED displays with I2C backpack (any color — mix or match!)
• USB power supply (or use an old MicroUSB phone charger if you’ve got one)
• Optional: Perma-Proto board for splitting connections.
• 3D printer and filament…or design your own enclosure with materials and tools that best suit your abilities.
• M2 x .4 x 4mm Phillips Flat Head Machine Screws

You will also need a soldering iron and related paraphernalia, some wire, etc. Read through the whole guide before planning any acquisitions.

Realistic Expectations