Quote
bobc
In practice all that is really needed is some concept of cooperative multitasking and event driven architectures, which is really bread and butter stuff for embedded programmers.
And even multitasking is not strictly required. In my APrinter firmware, I'm doing just fine with main loop plus interrupts. Yes, it certainly could be used to reduce response times, particularly with network stuff, but from my experience you can do pretty amazing stuff without it, especially with a fast CPU.
Oh, and let me just emphasize that my firmware, as far as I can tell, will work on RAMPS-FD, out of the box, with no issues, no pins should need changing. This includes homing, not losing any steps, inverted heaters and SD card (over SPI). From what I can tell, SD-RAMPS will work (the level shifter doesn't mind 3.3V inputs).
I would appreciate it very much if someone with a RAMPS-FD actually tested it, because I've only been testing it on an improvised setup with a RAMPS wired to a Due (my RAMPS-FD is yet to arrive). It is easy to build, and the github readme explains the build process clearly.
