It came out of a project that I did [1] from which I wanted to see what it takes to turn that into an actual product[2]. Hardware is a while other game than software especially in low quantity as you still need to deal with things like CE.

[1] https://sschueller.github.io/posts/vbz-fahrgastinformation/

[2] https://sschueller.github.io/posts/turning-a-project-into-a-...