yes, I am also hoping to get answers on how to work with platform-io without Arduino framework. A plain native way to edit, compile and upload code using no bootloader but avrdude/usbasp.
No predefined board, just a controller on a breadboard or on my own pcb.
There are snippets here and there but no concise instructions on what goes where or where to start. It must be possible, because I pretty much like the idea of a central programming environment for me (and possibly my students) independent on what system we want to write code for…