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3.12.2 Firmware for MK2.5 and MK2.5S is out  

Same Old Shane
Member Admin
3.12.2 Firmware for MK2.5 and MK2.5S is out

Greetings alll;
We are happy to announce that the 3.12.2 Firmware for MK2.5 and MK2.5S is out 


  • Thermal model updates
  • Update on E3D Revo
  • Self Test message fixed
  • FLC procedure updated
  • List of pull requests

This is the final release of firmware 3.12.2 focused mainly on thermal model-related improvements.

Thermal model updates (MK3/MK3S/MK3S+)

Autotune/Calibration temperature

Fixed the thermal model autotune/calibration temperature value to allow real print temperatures.
Before the G-code M310 A215 F1 failed.

Check Power and Capacitance values

Power and Capacitance parameters are now checked whether they are greater than zero.

Fixed incorrect sending of ERROR: via serial

In the previous firmware release, OctoPrint would send an M112 emergency G-code and “kill” the print during a thermal model anomaly. This is now fixed. Thanks to our OctoPrint community for reporting this issue.

Consistent TM wording

During the thermal model development, the terminology shifted in meaning. We decided to use this term to have clear and consistent wording for the thermal model.

  • The LCD calibration menu Temp model cal. is now Thermal model cal.
  • Messages related to the thermal model have also changed
    We added a page at (also shown during the TM calibration step in the wizard). Please read this Prusa help article for more information.

Update on E3D Revo (MK3/MK3S/MK3S+)

We would like to thank all of the community members who provided their TM calibration logs with the E3D REVO! This really helped to improve the TM development for PTC/REVO hotends.

E3D and Prusa Research have also started a task force to work on the Thermal Model for PTC/Revo hotends.

Self test message fixed

The Self test OK message was incorrectly set as an “alert” message and blocked actual alerts from being shown correctly. This has been solved.

FLC procedure updated

The message Is filament loaded? during the Wizard doesn’t timeout anymore and has to be confirmed to prevent First Layer Calibration (FLC) to continue without filament loaded.

List of pull requests

See here for more information

Please report any bug here:

Download Link:

How to flash the firmware:

Shane (AKA FromPrusa)

Posted : 02/03/2023 1:42 pm
Reputable Member
RE: 3.12.2 Firmware for MK2.5 and MK2.5S is out

To make it easiest on users with non-V6 hotends, did you ever consider adding an LCD menu option to disable the thermal testing so users don’t get the ‘anomaly’ message. I understand you can bypass it with pronterface, or OctoPrint, but a menu option would be the easiest for users to implement.. The whole strength of an open-sourced printer is to be able to safely mod it.. and if it takes this much to get 3rd party hot-ends working.. it might be better to provide an option to make that as easy as possible.. unless Prusa really wants people to stick to the V6.

Posted : 21/03/2023 1:43 pm