I was looking at the archived version [0], and I had a question.

Regarding their PCB design (visible on the bottom of the page, with additional details here [1], could someone explain why the optic part is separated from the rest of the board by a long, wavy connection?

(I am trying to learn more about PCB design ideas and principles.)

Thanks!

[0] https://web.archive.org/web/20220313204334/https://ploopy.co... [1] https://github.com/ploopyco/thumb-trackball/blob/main/hardwa...