I'm a big fan of Zephyr RTOS and I'm learning it by doing. Zephyr is not only a RTOS like say, FreeRTOS but it also abstracts the access to peripherals much like desktop operating systems do. This level of abstraction adds complexity, true, but at the end we have an application that can be easily ported (sometimes even without any coding) between different MCUs.
The same goes for FreeCAD. I was really surprised how capable this program is. It has it's drawbacks, but under Linux there is no better open-source option. And it's not hard to learn either. After just a few videos on YouTube I was able to design and print some simple examples. Shortly after I became confident enough to start something more serious, and thus the CoreXY plotter project has started.
Watching the AxiDraw videos on the Net, or even my own 3d printer is mesmerizing to me. And this is the main reason I decided to go with this idea : pure joy of watching a CNC machine doing it's job.
- Port GRBL to Zephyr and make it work with the UGS on my own hardware.
- Be able to draw complex shapes and as reliably (resolution, speed, noise reduction) as AxiDraw does.
- Emulate serial port over USB.
- Display a menu and whatnot. Like on Prusa printer. OLED.
- Printing from a SD card without a PC.
- Polished. Custom PCB. Cool looking.