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Firmware 4.0.1-FINAL for the Original Prusa MINI  

Jakub Dolezal
Firmware 4.0.1-FINAL for the Original Prusa MINI

Hi guys,

this a first public stable firmware upgrade, recommended to all users.

What is new?

  • Introduction to the MINI firmware
  • Fixes and improvements in 4.0.1
  • Other important repositories


A detailed description of changes:

Introduction to the MINI firmware

This is the first public release of the firmware for the printer Original Prusa MINI. This is a brand new branch of a firmware tailored for the Buddy board MINI developed by Prusa Research. Compared to the previous firmware for MK2S/MK3S, which is based on the 8-bit architecture is this firmware 32-bit and using ARM STM32F407 chipset.

The firmware is utilizing Marlin 2.0 to handle motion planning with multiple tweaks to comply with the Prusa in-house developed technologies. The user interface, WebUI and other parts of the firmware are fully developed at Prusa Research.

The board is capable of running RTOS (Real-Time OS). Therefore there are several parallel threads:

  • Marlin 2 (motion planning)
  • LCD GUI (graphic interface)
  • Networking (LAN and Wi-Fi communication)

Fixes and improvements in 4.0.1

Several printers from the initial batch were shipped with firmware 4.0.0. Users are advised to flash the newest firmware as it brings some fixes and improvements:

  • Improved homing algorithm
  • Improved dialogue for color change (M600)
  • Wizard stability
  • Filament sensor ON/OFF setting kept after a reset

Other repositories

Original Prusa MINI -
Buddy-board -
Heatbed -
IR sensor -


Supported printers:

  • Original Prusa MINI

Download link:

How to flash the firmware on MINI:

  1. Copy the firmware file (.bbf) onto the USB drive with FAT32 formatting
  2. Insert the flash drive in the MINI's USB port
  3. Turn the printer ON (or reset it)
  4. During the boot screen hit (press) the knob once
  5. A new screen will appear (if not, repeat the process) 
  6. Confirm you want to flash the firmware
  7. Wait till the firmware is flashed and printer fully boots into the home screen

Please report any bug here:


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

This topic was modified 2 years ago 2 times by Jakub Dolezal
Assembly manuals / Knowledge Base
The guy behind Prusa assembly manuals......
Posted : 26/12/2019 10:29 am
Active Member
RE: Firmware 4.0.1-FINAL for the Original Prusa MINI

Is this update enabling networking via lan 


Posted : 20/01/2020 3:15 pm
Prominent Member
RE: Firmware 4.0.1-FINAL for the Original Prusa MINI

Is the 4.0.2 posted in Downloads and drivers section final? Are there more detailed patch notes available than "support for mk3s lcd encoder"?

Posted : 06/02/2020 1:52 am
Honorable Member
RE: Firmware 4.0.1-FINAL for the Original Prusa MINI

(cross posted from the firmware thread)

Looking at all the changes noted into 4.0.2 on Github, versus the 4.0.2 on the download page which apparently only has the change for the different encoder, I believe there has been a mistake in naming. Based on the changes listed I believe the drivers page version should be more like 4.0.1a.

It is now 52 days since the last Mini firmware, excluding the hardware change version above... 🙁

Posted : 09/02/2020 12:48 pm