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MMU2/MK3 Firmware Communication Question  

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chuck.k
(@chuck-k)
Eminent Member
MMU2/MK3 Firmware Communication Question

I have written my own MMU2 controller firmware (written in C running on an Arduino ATMEGA2560). I have all the commands operating between the MK3 and my MMU2 firmware. I have a behavioral question for the developers, there are two commands that are critical during operation: T (tool change) and C (load filament to extruder head). My understand is that the T command (it is really T0,T1,T2,T3 or T4) just allows for the selection of different filament and stages it behind the finda sensor by about 25mm (out of the way of the extruder print head). The 'C' command takes the selected filament (from the T command) and loads it all the way to the bondtech gears in the Mk3. Since I can process the command stream coming from the mk3 (and respond appropriately I see some strange command sequences that I don't quite understand. For instance, I will see the following command sequence: T1, C0, T1, C0. The first 2 two commands make total sense - load filament 1 (T1) and then have it loaded to the extruder head (C0). I don't understand the second command sequence (T1, C0) since the filament is already at the bondtech gears. I obviously am misunderstanding the behavior of the command sequence - any help would be much appreciated. I have access to the MMU2 firmware source code and have not been able to solve this mystery on my own.

Opublikowany : 24/09/2018 5:06 am
chuck.k
(@chuck-k)
Eminent Member
Topic starter answered:
Re: MMU2/MK3 Firmware Communication Question

I figured the problem out today. The T command (T0 through T4) loads the filament all the way to the bondtech extruder gear. The C0 command loads the filament just past the extruder gear so that the filament is engaged in the bondtech gear. The C0 command is always preceded by a T command.

Opublikowany : 25/09/2018 7:13 am
3d-gussner
(@3d-gussner)
Reputable Member Prusa-Translations
Re: MMU2/MK3 Firmware Communication Question


I figured the problem out today. The T command (T0 through T4) loads the filament all the way to the bondtech extruder gear. The C0 command loads the filament just past the extruder gear so that the filament is engaged in the bondtech gear. The C0 command is always preceded by a T command.

just look in the github sources for the mm-control-01 and Prusa firmware which commands are used. Pretty sure you can compile the mmu firmware on a atmega 2560.

Opublikowany : 27/09/2018 7:56 am
PJR
 PJR
(@pjr)
Antient Member Moderator
Re: MMU2/MK3 Firmware Communication Question



I figured the problem out today. The T command (T0 through T4) loads the filament all the way to the bondtech extruder gear. The C0 command loads the filament just past the extruder gear so that the filament is engaged in the bondtech gear. The C0 command is always preceded by a T command.

just look in the github sources for the mm-control-01 and Prusa firmware which commands are used. Pretty sure you can compile the mmu firmware on a atmega 2560.

Leonardo. It compiles just fine with latest Arduino UI.

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…

Opublikowany : 27/09/2018 11:03 am
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