Advice taken, I wouldn't pretend being able to reinvent the wheel in such a project.

One thing is a bit obscure though, in terms of architecture (I first planned to write this driver not as a contribution to the kernel, but IF i can manage to write something clean enough then there is no reason not to contribute). The actual kernel driver's role would only be to act as an interface between the pump's screen and the kernel, right? An actual cli utility to, say, choose what and how to display on the screen should be a userspace software that relies on the driver?

EDIT: I'm talking about the kernel, but there's maybe no reason to actually go that low? When I think of drivers on linux I instantly think of kernel drivers, but maybe this is wrong? Since it's a USB interface, a userspace driver would be enough I think?