Firmware 3.7.0-RC1 for Original Prusa i3 MMU2S & MMU2  

Firmware 3.7.0-RC1 for Original Prusa i3 MMU2S & MMU2

WARNING: Note that MK3S, MK3, MK2.5S and MK2.5 are different printers! Each has its own firmware file!!!

Hi guys,
this is an upgrade of the firmware for the Original Prusa i3 printer. Keep in mind this a release candidate (testing version) for experienced users 😎

What is new?
–> 7x7 mesh bed levelling
–> MMU2S fast mode (MK3S + MMU2 only)
–> Improved T-code load (printers with MMU2)
–> Change filament fix (printers with MMU2)
–> Eject filament contains ramming (MMU2 printers)
–> The informative message during switching between normal and stealth modes
–> Improved behaviour when removing SD card
–> Autoload disabled in extruder info (MK3) and sensor info (MK3S) menu

7x7 mesh bed levelling
It is now possible to increase mesh bed levelling XY resolution by activating measuring 49 points in 7x7 mesh. This can be done in the menu "Settings -> Mesh bed levelling". There is also a possibility to change the number of measurements for each point from 1 (fast, but less accurate) to 5 (most accurate) and also turn on/off magnet compensation. PINDA probe Z-coordinate measurement can be influenced by heatbed magnet proximity (by approximately 80 um) and thus distort mesh bed levelling calibration. If magnet compensation is off, all 49 points are measured and used for mesh bed levelling correction. If magnet compensation is on, for chosen points (which may be affected by magnets) are counted from surrounding points. Also, the mesh bed levelling Z-measurement algorithm was slightly modified to make the whole process faster. No G-code modification is needed. Standard G80 G-code will behave according to settings which were set in "Settings -> Mesh bed levelling" menu. It is also possible to use G80 Nx Ry G-code, where x is a number of mesh bed levelling points in one axis (3 or 7 are valid values) and y is number of Z-measurements for each point (which are then averaged). Settings done directly in G-code has higher priority then settings which are set in the menu.
I would like to thank all who were working on this feature and helped to implement it to our Prusa FW, especially @stahlfabrik, @mionut and @3d-gussner.

MMU2S fast mode
On MK3S printers with MMU2 connected it is possible to switch MMU between fast and stealth mode. This can be done in the menu "Settings -> MMU mode". With MK2.5S MMU runs always in stealth mode.

Improved T-code load
Load sequence was slightly modified to reduce missing layer error count.

Change filament fix
When changing filament (M600 G-code, menu "Tune-> Change filament" or filament runout) on printers with MMU2 connected, there is a possibility to re-do filament unload and load by choosing "Filament not loaded". This, however, didn't work properly in some scenarios and filament could remain stuck between extruder Bondtech pulley and nozzle. This has been fixed.

Improved behaviour when removing the SD card
When SD card is inserted SD card menu is automatically shown. When SD card is removed menu which was active when the SD card was inserted is restored.

Autoload disabled in extruder info (MK3) and sensor info (MK3S) menu
These menus serve for checking if the filament sensor works properly. The filament can be now inserted (without triggering load function) to check if sensor state changes.
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Supported printers:
Original Prusa i3 MK3S MMU2S
Original Prusa i3 MK3S
Original Prusa i3 MK3 MMU2
Original Prusa i3 MK3

Original Prusa i3 MK2.5S MMU2S
Original Prusa i3 MK2.5S
Original Prusa i3 MK2.5 MMU2
Original Prusa i3 MK2.5

Download link:
https://github.com/prusa3d/Prusa-Firmware/releases/tag/v3.7.0-RC1

Firmware flashing guide:
https://manual.prusa3d.com/Guide/Upgrading+the+firmware+v1.5/66

Please report any bug here:
https://github.com/prusa3d/Prusa-Firmware/issues

As always, we wish you happy printing and look forward to your feedback!