Thanks @ChrisGammell! If nothing else, this will hopefully have some blinky lights to impress my kids. You are correct, this version doesn't have an inertia sensor of any kind. I was hoping to just adjust the delay loop in the code to get the timing right for an average spin speed. But it could be that I need to put in an accelerometer or something in version 2. I will find out in a week or two when the boards arrive! Either way it's been a fun learning experience for me.
There's another potential problem with my design. The center bearing in most fidget spinners seems to be friction fit. In my design, I was intending to also have the bearing friction fit up against the pcb wall. However, there seems to be some folks in the hackaday threads that question whether this will work. If it doesn't work, my backup plan is to use some kind of adhesive, maybe crazy glue or something to keep the bearing in place. I added some solder tabs around the bearing hole in an early version, thinking maybe I could secure it with solder. But I'm questioning my ability to get a strong solder joint on something that large. Do you recall how they solved that problem in the blinky version you saw last night? Thanks for checking out the project!