So far I’ve read that MMU2S should work with its own clipper firmware and software.
That seems very complicated to me.
With the Prusa MK3S, the MMU2S is connected to a serial port.
MMU2S receives commands similar to the GCODES sent.
The filament change is not very time critical.
Is it possible to connect an unmodified MMU2S to a Klipper firmware?
If yes, how do you go about it?
If not?
I could imagine developing something like that, since it probably won’t be very complex.
So far I haven’t dealt with the Klipper software much.
How do I get an entry?
Where in the code can I find the GCODES that Klipper already knows?
Is there a developer guide somewhere that will help?
MMU2S has an own MCU regardless if you are running Klipper or Marlin. This MMU2S MCU needs a firmware to be able to receive and process commands. This fact is equally independent of Marlin or Klipper.
Since the philosophy of Marlin an Klipper is different, the Klipper world runs a Klipper MCU instance on the MMU2S to make it react to the respective commands.
Also in the Klipper world the logic and commands of the MMU2S is implemented via Klipper macros that can be called from the slicer at the required locations and timings.
Ref to https://github.com/Klipper3d/klipper/blob/master/config/sample-mmu2s-diy.cfg
For any Klipper development in general ref to the “Developer Documentation” on https://www.klipper3d.org/
In the documentation you will also find all the supported GCODEs.
The official MMU2S device from Prusa is not currently supported by Klipper. It would need a developer willing to implement it (either by porting Klipper to the micro-controller or by implementing support in Klipper to communicate with the existing firmware). Several users have just replaced the controller hardware and used a regular low-cost control board running standard Klipper instead - as the control board in the official mmu2s is quite quirky. The sample-mmu2s-diy.cfg cited above is for the latter.
I don’t own this hardware, so it’s possible I have some of the details above incorrect.
I’d like to work on this topic, but I am new to klipper an will need some support. I own the hardware (and like to use it with klipper).
My favorite: Implement a solution which uses the existing firmware, even if this might not be the best approach. However, it is easy to implement and should not take long and it’s the most convinient solution for the end user. However, I will be able to work on this topic by mid of february next year the earliest.