I made a rotary encoder. Due to its 60 steps (6 degree) resolution it suits to make clocks.
There is a very good and detailed description of the single track Gray code here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6111776/.
My instructable is only about physical realization now.
![](https://content.instructables.com/ORIG/FQD/6VBR/KVP8ZDEM/FQD6VBRKVP8ZDEM.png?auto=webp&frame=1&width=1024&height=1024&fit=bounds&md=23677da35d6ae0d42d93fef87e7bc0c7)