We feature a lot of clock builds on HaD, and the reason is that they are cool. Even simple ones are cool. Not everyone can say they built a clock. [Chris] took a ride on the DIY Clock train and came up with this LED-based clock that is controlled by an ATtiny84 chip.
The clock has 24 LEDs total, 1 for each hour and 1 for every 5 minute increment. The 24 LEDs are arranged in 2 concentric rings. To display the hour, both LEDs at the same angle are lit up. To show the minutes, just the inner LED is lit. The main image above shows 6:40.
If you are familiar with the ATtiny84 you know that it only has 12 in/out pins, which is significantly less than the amount of LEDs that need controlling. [Chris] decided to use some 74HC595 shift registers to increase the IO pins on the ATtiny. The entire build is installed on a protoboard with quite a bit of point-to-point wiring. A simple tinted plastic case finishes the project and gives it a modern look.
[Chris] made the code for his clock available in case any readers are interested in making one.