[FR] Per-axis stepper driver selection

[iosonopersia]

@thinkyhead , @MagoKimbra , @GMagician , @Sineos , @ejtagle This is an idea which was born in the discussion here: #11098

The suggestion made below comes from me and @GMagician :

---

I propose a different approach, define driver for every installed axis like

Configuration.h:

#include "supported_drivers.h"
[...]
#define X_DRIVER  DRIVER_DRV8825
#define X2_DRIVER  DRIVER_DRV8825
#define Y_DRIVER  DRIVER_A4988
#define Z_DRIVER  DRIVER_TMC2100
#define E0_DRIVER DRIVER_TMC2130
[...]

and each driver include may do something like...

supported_drivers.h:

#define DRIVER_DRV8825  ./drivers/drv8825.h
#define DRIVER_A4988  ./drivers/a4988.h
#define DRIVER_TMC2130  ./drivers/tmc2130.h
[...]

drv8825.h

#ifndef MINIMUM_STEPPER_PULSE
  #define MINIMUM_STEPPER_PULSE 0
#endif

#if MINIMUM_STEPPER_PULSE < 2
  #undef MINIMUM_STEPPER_PULSE
  #define MINIMUM_STEPPER_PULSE 2
#endif

a4988.h

#ifndef MINIMUM_STEPPER_PULSE
  #define MINIMUM_STEPPER_PULSE 0
#endif

#if MINIMUM_STEPPER_PULSE < 1
  #undef MINIMUM_STEPPER_PULSE
  #define MINIMUM_STEPPER_PULSE 1
#endif

Drivers.h

#ifdef X_DRIVER
  #include X_DRIVER
#endif
#ifdef Y_DRIVER
  #include Y_DRIVER
#endif
[...]

This is more tedious for programmers but easier from user perspective. The user doesn't need to read datasheets to understand which is the slowest one.

---

Then, every file that will need to use driver-specific values (such as MINIMUM_STEPPER_PULSE), will need to include Drivers.h

If the idea is ok, we can open a PR to try implementing it. What do you think?

[teemuatlut]

I don't think we need separate files for each driver type if all it contains is min step pulse and max step frequency. This sounds a bit like it could be added to stepper_indirection. You also need to find the max value between all the configured drivers.

But overall as an idea I think it would be useful for Marlin to be aware of the driver types it is using. Even if they wouldn't require additional configuration and communication and other smart features.

I'll also post here what I said in the other thread about how the TMC drivers will be defined in the future:

Possibly related on driver types (coming soon): teemuatlut/Marlin@00d735e

Though not about timings but the TMC driver selection.

[iosonopersia]

Ok, I mostly agree. Just as a recap, we now have these driver-specific values:

#define MINIMUM_STEPPER_DIR_DELAY
#define MINIMUM_STEPPER_PULSE
#define MAXIMUM_STEPPER_RATE

[forkoz]

If I still had a different driver for E, I'd be screwed right now. Was going to buy only 3 TMC's too, there would be no way to fix it. A few weeks ago I installed 4th LV8729 by chance to play with E amperage so skated by pure chance.

[Sineos]

I have no strong feelings how it should be implemented. From my (users) point of view, it should:

• be a setting in Configuration.h since it became a relevant setting for the printer's operation similar to the board or end-stops
• harmonize all driver variants
• allow per axis / stepper setting
• include the relevant timing parameters
• tune the entire system to comply with the slowest timings / max frequency on mixed configuration automatically
• offer manual settings for users with exotic needs

[GMagician]

@Sineos I think that playing with defines and #if defined(xx) something may be done.

[GMagician]

@teemuatlut I don't want to overwrite your work. I'll try to address this when you will release yours (or maybe if you think that this solution will destroy all your work, and you think to stop it, I'll start sooner)

[teemuatlut]

It may take a while before I make the PR as it's not the first one in line that I have.

[thinkyhead]

Move discussion to #11133

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