It is using software (ESP32) to hardware serial (RPi).

Figured out the code to program the touch screen so I made own basic one to start/stop and track elapsed time.

Soldered it so now it has the top board as initially envisioned.

It is now much bulkier.

There is still more work to do but I have all the base parts in eg. bi-directional communication.

I have some more design/printing to do so it stays on straight on my hat. Next time there is good weather fly and record footage for training the ML model which is an unknown to me at this time.

Videos below