What PCBs do you have left over? Anything that might be useful in another project?
I've got about 20 TLC boards and 100 LED boards that haven't found their way into a project yet. A few weeks ago I started with another clock. A very different one. But haven't had time to finish it.
The electronics shouldn't be more complicated than the bi-color dual matrix LED shields I make (and sell), essentially 180 LEDs driven by 4 shift registers plus a darlington array. Arranging them in a circle would be some challenge. Arranging them NICELLY would be even a bigger challenge.
That is exactly the reason why I didn't use a matrix. I've used TLC5940s. They can be daisy-chained so I figured I could also chain them with pcb's and cables. It's just a long string of tlc's going round.
It also gave me a nice resolution on the LEDs (4096).
Unfortunately the LED were of poor quality and there was some color difference between them.