I would like a $55 board that turns a RPi into an Arduino. In the sense that: I 'flash' some code to it, then when I plug it in it powers on and just 'works' (per my code), and when I unplug it it does not self destruct, and can be plugged in again (and again) without issue.

Bonus points for powering from whatever the display connector is.

(Portenta H7 is getting there coming from the Arduino end, but still woeful cpu capacity, and the one I got had display issues)