How it's work?

Every 0.5 sec CPU wake up(cycle iteration time 100 nS) and increase milliseconds value and come sleep mode(3 uA).

If you press button "TIME();" it show hours and minutes(0.5 seconds per value) in binary mode in 4 LEDs.

Video demonstration:

https://youtu.be/qP_2BFFjp1M

Source code(for Arduino IDE - "t13B Watches.ino") here:

https://github.com/techn0man1ac/ATtiny13BinaryWatches/

The thickness of the board is recommended to take 0.8mm otherwise it may not fit into the case.

by Techn0man1ac Labs, 2023