Still obsessing over a modular stackable system.

M10cube or Ruslan's building set both start from first principles, if we design everything from scratch how does it look.

I'm interested in a more pragmatic approach; How can we make what already exists work better together?

I've played with the M5stack format and kicked around using the Beagleboard pinout

Arguably the Pi Pico format is becoming a 'default' footprint for microcontroller work. It at least has the benefit of having plenty of pins.  It's a very narrow board though, not much room to play with.

So how does it look if we stick with the pico pinout (and maybe get a bit opinionated about how it's used, but break out the width to 28mm spacing?

The 'pico' one

Would be used as the compatibility layer between the narrow and wide spacing.

They could use short pins

They would be compatible with existing open hardware pico bits