:mouse: Blackberry rusty mouse

The purpose of this project is to build a blackberry-trackball mouse and glue it to the middle of an (allegedly) ergonomic keyboard... in Rust Embedded, for the STM32F042 :)

dev_board

This came about from twitter idea to board, then to Rust Embedded. The code is based on RTIC rust-embedded framework (formerly known as RTFM). It exclusively uses interrupts and also works on OSX, not only Linux (wink wink, nudge nudge, James ;P).

:rocket: Future improvements shall you take this code with you

DPI tweaking to have a better trackball accuracy or speed/stepping.
Button debouncer.
Remove one of the buttons of the PCB, since it conflicts with one of the trackball GPIOs... oops, hardware blopper ;)
Add acceleration like @LSChyi did?
Perhaps a clever (optical) system to make this experiment actually practical and useful :P
On OSX the mouse works fine. On GNU/Linux systems, the mouse might stop responding after ~30 seconds of use. This could be related to the Linux USB autosuspend subsystem.. Try to fix that from the firmware so that it works everywhere?
If enough people show interest and choose to sponsor me, I would love to look at how to:
1. Understand the flash process of the Beken 3231.
2. Implement an LLVM backend for the ARM968E-S and have rustc working with it.
3. Goal: have a sub-$1 bluetooth IC that potentially does all we need and more plus learn to implement an LLVM backend from scratch. Also provide a way to upcycle bluetooth hardware, keeping it away from the dumpster.
~~Write a simplified RTIC example to return the favour to that amazing rust-embedded community~~: Done.

And all the folks from the RTIC matrix.org community for patiently guiding and helping me in this experiment.