6.2.0 Firmware for Original Prusa MK3.5S
Summary
- New features
- Added an option to save printer logs to a text file
- Expanded GPIO functionality (MK4/S, MK3.9/S, MK3.5/S)
- Toolhead and hardware menu overhaul
- Improved filament management
- “Set Ready” button
- Connect header status icon
- Nozzle information for Prusa Connect
- Mapping screen from Prusa Connect
- Japanese language support on MINI
- Changes
- Disabled switched fan test (XL)
- Bugfixes
- Tweaked print fan selftest (MK4S)
- Tweaked Y-axis test (MINI) (#4218)
- Fixed the G-code parser parsing parameters from comments (#4261)
- Fixed dialog popping up during print for XL enclosure HEPA filter (XL) (#4309)
- Fixed not sending end of print over serial line (#4331)
- Fixed “Extruder steps per unit” in the experimental settings menu resetting to wrong value (#4330, PR #4341)
- Fixed a problem with printing plain G-codes while downloading
- Fixed a redscreen when opening the Wi-Fi wizard during print (#4336)
- Wi-Fi stability improvements
- USB media prefetch
- Improved preview loading during file transfer
- Fixed skipping a G-code after pause
- Fixed a situation where the HF nozzle wasn’t being pre-selected by default on new installations (MK4)
- Fixed Z position bug after power panic, re-enabled power panic (MK3.5)
- Unused tools are now cooled down on the print start (XL)
- Fixed tools not heating after power panic (XL)
- Reduced cases of extruder stopping mid-print (XL)
- Fixed motor skipping/crashes in some situations (XL)
- Fixed considering steel sheet uncalibrated when minimum value set (MINI/MK3.5)
- Added option to reduce display refresh speed (all except MINI)
- Translations
- Regressions
- Dropped backward compatibility of loaded filaments
- Model changes
- CoreXY model calculations
- Known bugs
- Numeric error accumulation possibly causing layer shifts
This is the stable release of firmware 6.2.0 featuring major changes and improvements. This release is recommended to all users.
If you are not using alpha/beta releases, upgrading from previous versions will give you plenty of new options and features to dig into. We’re covering everything important in these release notes, including changes introduced in the previous release candidates (RC).
Previous releases:
New Features
Added an option to save printer logs to a text file
An option has been added to the Settings → System menu to “Save Logs To File”. While this is enabled, printer logs (also sent to the USB serial if the baud rate is set to 57600) are saved to the “log.txt” file in the root directory of the connected USB drive.
This feature is especially useful for troubleshooting failing selftests as the logs could contain more details.
It is necessary to turn this feature off from the menu before disconnecting the USB drive to ensure that the logs are saved and the USB drive does not get corrupted.
Unfortunately, this feature did not fit into our japanese MINI firmware version (because of the extra japanese characters). But don’t worry, we’ve done some cleaning up in the 6.3 version and we will make it fit there!
Expanded GPIO functionality
The GPIO functionality has been enhanced in this release. While M260 and M261 API was already introduced in version 6.1.2, we’ve now added dedicated support for the Prusa-specific GPIO expander through G-codes M262 - M265.
These new G-codes extend the control over the GPIO expander, making it more versatile and powerful as we now support input on GPIO, allowing users to trigger custom-defined macros in G-code format, up to 1024 bytes in size. Full details on this feature, along with G-code usage examples, are available in our GPIO article.
Toolhead and hardware menu overhaul
The toolhead and hardware menu has been reworked, allowing users to set specific parameters for each individual toolhead and also for all of them at once. This also includes checks for hardened or high-flow nozzles, ensuring that your toolhead is always properly configured.
Improved filament management
We’ve revamped the filament management system, offering more customization and control for users:
- Hide filaments: Users can now choose to hide any filament types from the menus (e.g. preheat menu, filament load menu, etc.)
- Reorder filament: You can now manually change the order in which filament types appear.
- User filaments: Introducing user-defined filament options for more personalized settings.
- Custom filament Settings: Ad-hoc definition can now be made during the filament loading process, allowing you to tweak parameters - depending on loaded material.
- Abrasive materials warnings: If you’re working with abrasive materials (e.g., carbon or glow-in-the-dark filaments) without a hardened nozzle, the printer will now provide a warning during filament loading or print start.
- Loaded filament display: A new menu option “Loaded filament(s)” shows what filament is currently in use. Filament categories are indicated as Preset, User-defined, or Custom. On the MINI, some information is hidden due to screen size constraints.
“Set Ready” button
If your printer is set up in the Prusa Connect, you can now mark the printer as “Ready” directly from the print finish screen.
Connect header status icon
We added a new header icon, indicating Connect status:
- “C” when the printer is registered to the Connect (and grayed out when there is no network connection)
- “☑” when the printer is registered to the Connect and the printer is “Ready”.
Nozzle information for Prusa Connect
We’ve integrated detailed nozzle data into Prusa Connect, ensuring that users can now view nozzle-related parameters for all tools directly from the Connect.
Mapping screen from Prusa Connect
This release introduces support for multi-tool filament mapping screen from Prusa Connect. While this feature is still in development and thus not fully functional, users will notice incremental updates as we continue to integrate these tools.
Japanese language support on MINI
With this release, we’ve introduced Japanese as an official language option for Original Prusa MINI and MINI+ printers, allowing a broader global audience to interact with the machine more intuitively.
Changes
Disabled switched fan test (XL)
We have decided to remove the switched fan test from the XL. All our XL toolheads come preassembled from the factory, so there is no need for switched fan test. The fans have very similar properties and the test was not able to distinguish them with a 100% reliability issue #3480
Bug Fixes
Tweaked print fan selftest (MK4S)
We’ve increased the tolerance for the MK4S print fan selftest to match the manufacturer specifications.
Tweaked Y-axis test (MINI) (#4218)
We’ve increased the Y-axis selftest tolerances to pre-6.2 numbers to avoid regression of the selftest suddenly not passing for some customers.
Fixed the G-code parser parsing parameters from comments (#4261)
We have fixed a bug in the firmware that was causing interpreting some comments as G-code parameters.
Fixed dialog popping up during print for XL enclosure HEPA filter (XL) (#4309)
The HEPA filter expiration dialog should now only pop up at the start and at the end of prints, never during it.
Fixed not sending end of print over serial line (#4331)
There was a regression where we accidentally stopped sending MSG_FILE_PRINTED to the serial line on print end. This has been fixed.
Fixed “Extruder steps per unit” in the experimental settings menu resetting to wrong value (#4330, PR #4341)
When clicking on “Extruder steps per unit” in the Experimental Settings menu, the item was reset to a wrong default value. This has been fixed by @bkerler.
Fixed a problem with printing plain G-codes while downloading
We have discovered and fixed a bug that was possibly causing the printer to read from plain G-code file sections that have not yet been downloaded. This did not affect the binary G-codes.
Fixed a redscreen when opening a Wi-Fi wizard during print (#4336)
Trying to open the Wi-Fi wizard during print should no longer result in a redscreen. It is still not a good idea, though, as it interrupts the print.
Wi-Fi stability improvements
Several bugs related to Wi-Fi connectivity have been addressed, including crashes caused by high outgoing traffic. This should improve overall network stability during data-intensive tasks.
USB media prefetch
A media prefetch feature has been overhauled, addressing recurring USB errors by improved handling of data during the print process. This should result in fewer connectivity issues during printing.
Improved preview loading during file transfer
We've optimized the print preview during file transfer from Prusa Connect. Previously, the preview appeared only after 50% of the file was downloaded, even though the necessary data was available earlier. This fix improves polling frequency and task prioritization to ensure faster preview generation and quicker print start times.
Fixed skipping a gcode after pause
We fixed a bug causing the first gcode after unpause to be skipped. This also presented itself when bed leveling failed, because the failure resulted in a print pause.
Fixed a situation where the HF nozzle wasn’t being pre-selected by default on new installations (MK4)
After a factory reset, the printer will be configured as the MK4S. However, the nozzle was set to standard instead of high-flow, which is now fixed.
Fixed Z position bug after power panic, re-enabled power panic (MK3.5)
In 6.2.0-alpha2, we have temporarily disabled the power panic for the MK3.5 printer, because the printer could resume to a wrong Z position. This has been fixed now and the power panic feature was re-enabled.
Unused tools are now cooled down on the print start (XL)
The “Preheat” function preheats all tools on the XL. When printing a model that doesn’t use all the tools, the unused toolheads were left heating for the whole duration of the print. Moreover, they couldn’t even be turned off by G-code, because G-codes follow the tool mapping, making the unused tools inaccessible.
To remedy this, we now turn off all tools that are not mapped to anything at the start of the print.
Fixed tools not heating after power panic (XL)
We fixed a bug that was causing tools rarely not to heat up after power panic on the XL machines #3393.
Reduced cases of extruder stopping mid-print (XL)
We have received reports of the extruder motor stopping extruding on some XL machines, and implemented a fix that should remedy the problem for at least a portion of the affected users. However, we are still investigating the issue, and apologize for the inconvenience. The printer should now also be able to detect the extrusion dropout and go into a redscreen instead of continuing the print (17536 Extruder error). If the issue still persists for you after this update, please contact our support team.
Fixed motor skipping/crashes in some situations (XL)
We have fixed a number of kinematics bugs regarding XL toolchanges and homing #4240.
Release notes: https://github.com/prusa3d/Prusa-Firmware-Buddy/releases/tag/v6.2.0
Fixed considering steel sheet uncalibrated when minimum value set (MINI/MK3.5)
When sheet Z-offset was set to the minimal or maximum value, it was wrongly considered uncalibrated. This has been fixed.
Kudos to @jenda122 for analyzing the issue #4295.
Added option to reduce display refresh speed (all except MINI)
We’ve received reports about occasional display irregularities, and we’re working to identify the cause. To assist with this, we’ve added a new “Display Refresh Speed” option in the “Settings → Hardware” menu.
If you’re experiencing display issues, please try setting this option to “Low” and let us know if it resolves the problem. We understand this setting may significantly slow down the display; this is a temporary measure only to allow us to identify the problem. We will issue a proper fix once we collect the data.
Regressions
Dropped backward compatibility of loaded filaments
Due to a bug in the older versions of firmware, we had to drop backward compatibility of the currently loaded filament information. If you downgrade from 6.2.0-RC1 to an older firmware version, the printer will forget what filaments are loaded. Upgrading to 6.2.0-RC1 from older versions will work without any data loss.
Model adjustments
CoreXY model calculations
The CoreXY physics model has been revised to better align with the actual physical system, ensuring more accurate and consistent movement calculations.
Known bugs
Numeric error accumulation possibly causing layer shifts
We have recently discovered a numeric error accumulation bug that could cause layer shifts (especially on prints with gyroid infill). We are currently in the process of testing a fix, which should hopefully get released in one of the next releases - this is not a regression and we don’t want to delay this release any further.