Teacup_Firmware VS SunriseLight

Ooh another fun one you may be interested in is how I wrote Teacup's config handling - the user has to provide a config.h with various macros defining their machine setup, and then multiple separate parts of the codebase redefine those macros and re-include the file to build various structures and constants at compile-time

Since then I've made lots of things like audio amplifiers and effects, motor controllers, 3d printer controllers and firmware (and subsequently smoothieboard), muscle stimulators, bluetooth LED strip controllers, etc

Teacup can go pretty fast too, I think I've seen it clocked at 48k @ 20MHz although that may have been across 4 motors at once.

See here and here for an example from my ESC project, or this example from Teacup

https://www.airspayce.com/mikem/arduino/AccelStepper/classAccelStepper.html says "The fastest motor speed that can be reliably supported is about 4000 steps per second at a clock frequency of 16 MHz on Arduino" which is pretty poor - teacup can hit something like 10× that when controlling 4 steppers, and also comes with a non-blocking state machine based gcode parser ;)

Teacup had decent performance last time I checked, but it's more a complete firmware project rather than a library.

That's hard enough just with linear acceleration let alone complex functions - might be worth converting it to line segments host-side and just streaming basic gcode to a 3D printer firmware over the serial port.

Last time I checked, Teacup can do something like 40kHz on an atmega - might be worth having a play with that?

AccelStepper may interest you, and I think Teacup can go even faster.

The latest what? Teacup? Marlin? Aprinter? Repetier? GRBL? Something else?

Redshift has code to calculate that locally which I use in my sunrise light project

Since then I've made lots of things like audio amplifiers and effects, motor controllers, 3d printer controllers and firmware (and subsequently smoothieboard), muscle stimulators, bluetooth LED strip controllers, etc

Here's a bluetooth RGB strip controller I made a couple years ago if you want an example.

hackaday.com has a zillion links to examples; here's one two three four of mine and I've also got a laundry list of companies I've helped but whose technical details I can't legally publish (note that I've assisted many but not all of the companies in that link)

eg for this project my available inputs were intermittent 12v power, bluetooth, and the current time and location; and the desired output was 3× high current low-side switches that produced 12v RGB PWM corresponding to the colour temperature and brightness of the sky - so we need a bluetooth microcontroller, battery backup to keep time when 12v is absent, some battery management which wanted 5v in, a 12v buck to feed it, some MOSFETs, and redshift or similar code to plug into things.

Here's one I made earlier although it targets NRF52 and doesn't use Arduino libraries.

I've got a similar project here, and most of the complication is for battery management - the actual LED strip drive is even simpler than yours because I chose MOSFETs that work nicely with 3v3 gate voltage :P

If you're curious here's a couple of my AVR projects (not using Arduino libraries at all), and here's an NRF52 one

I guess my Sunrise Light project could have been built on Arduino's libraries since an NRF52 core exists, but I didn't do that…

For example, this old project of mine uses an NRF52832 (which is substantially similar to the '840, just missing USB) and it offers several services and characteristics including a battery level service, a DFU service, and a custom service for actually controlling it.