Mirror of official Prusa firmware with custom changes.

Kevin Lee 00c5f5d96c Minor fixes for flex filaments 2 weeks ago
.github 564bab7308 Update issue templates 6 months ago
Catch2 68ce375a18 Add Catch2 test framework. Add example test. Add tests build instructions. 2 years ago
Firmware 00c5f5d96c Minor fixes for flex filaments 2 weeks ago
LinearAdvanceTest b09c394031 Gcode tests for LA 1.5 2 weeks ago
Tests dbe2ed4150 Fix pause/resume when using M25/M601 6 months ago
lang 8d946ef76e Final FW 3.9.0 translations (#2666) 2 weeks ago
.editorconfig deff8dcfde MK3 3 9 0 missing translations (#2646) 3 weeks ago
.gitattributes deff8dcfde MK3 3 9 0 missing translations (#2646) 3 weeks ago
.gitignore 41da8862b4 MK3 3.9.0 Italian fix (#2663) 3 weeks ago
.travis.yml acc71232ea Suppress Arduino SocketListener messages. 11 months ago
CMakeLists.txt 2e25a853f4 Added prusatat test 10 months ago
LICENSE a4a80b3eb7 MK2 Firmware release. 4 years ago
PF-build.sh 41da8862b4 MK3 3.9.0 Italian fix (#2663) 3 weeks ago
README.md 61e1cc60f4 Correct product names 4 weeks ago
README_cz.md ecb2a6e02c Update README.md. 1 year ago
build.sh f23dd6bed4 Hard reset to prusa3d/mk3 and added changes 4 months ago
prepare_winbuild.ps1 d0e3e9d2e2 Build firmware under Windows 10 64-bit ... 1 year ago
test.sh c571355db5 Run tests and build all variants on Travis-ci. 1 year ago


Prusa Firmware MK3

This repository contains the source code and the development versions of the firmware running on the Original Prusa i3 MK3S/MK3/MK2.5S/MK2.5 line of printers.

The latest official builds can be downloaded from Prusa Drivers. Pre-built development releases are also available here.

The firmware for the Original Prusa i3 printers is proudly based on Marlin 1.0.x by Scott Lahteine (@thinkyhead) et al. and is distributed under the terms of the GNU GPL 3 license.

Table of contents



  1. Clone this repository and checkout the correct branch for your desired release version.

  2. Set your printer model.

    • For MK3 --> skip to step 3.
    • If you have a different printer model, follow step 2.b from Windows build
  3. Run ./build.sh

    • Output hex file is at "PrusaFirmware/lang/firmware.hex" . In the same folder you can hex files for other languages as well.
  4. Connect your printer and flash with PrusaSlicer ( Configuration --> Flash printer firmware ) or Slic3r PE.

    • If you wish to flash from Arduino, follow step 2.c from Windows build first.


The script downloads Arduino with our modifications and Rambo board support installed, unpacks it into folder PF-build-env-\<version\> on the same level, as your Prusa-Firmware folder is located, builds firmware for MK3 using that Arduino in Prusa-Firmware-build folder on the same level as Prusa-Firmware, runs secondary language support scripts. Firmware with secondary language support is generated in lang subfolder. Use firmware.hex for MK3 variant. Use firmware_\<lang\>.hex for other printers. Don't forget to follow step 2.b first for non-MK3 printers.


Using Arduino

Note: Multi language build is not supported.

1. Development environment preparation

a. Install "Arduino Software IDE" from the official website https://www.arduino.cc -> Software->Downloads

It is recommended to use version "1.8.5", as it is used on out build server to produce official builds.

b. Setup Arduino to use Prusa Rambo board definition

  • Open Arduino and navigate to File -> Preferences -> Settings
  • To the text field "Additional Boards Manager URLSs" add https://raw.githubusercontent.com/prusa3d/Arduino_Boards/master/IDE_Board_Manager/package_prusa3d_index.json
  • Open Board manager (Tools->Board->Board manager), and install Prusa Research AVR Boards by Prusa Research

c. Modify compiler flags in platform.txt file

  • The platform.txt file can be found in Arduino instalation directory, or after Arduino has been updated at: "C:\Users\(user)\AppData\Local\Arduino15\packages\arduino\hardware\avr\(version)" If you can locate the file in both places, file from user profile is probably used.

  • Add "-Wl,-u,vfprintf -lprintf_flt -lm" to "compiler.c.elf.flags=" before existing flag "-Wl,--gc-sections"

    For example: "compiler.c.elf.flags=-w -Os -Wl,-u,vfprintf -lprintf_flt -lm -Wl,--gc-sections"


In the case of persistent compilation problems, check the version of the currently used C/C++ compiler (GCC) - should be at leas 4.8.1; If you are not sure where the file is placed (depends on how "Arduino Software IDE" was installed), you can use the search feature within the file system

Name collision for "LiquidCrystal" library known from previous versions is now obsolete (so there is no need to delete or rename original file/-s)

2. Source code compilation

a. Clone this repositoryhttps://github.com/prusa3d/Prusa-Firmware/ to your local drive.

b. In the subdirectory "Firmware/variants/" select the configuration file (.h) corresponding to your printer model, make copy named "Configuration_prusa.h" (or make simple renaming) and copy it into "Firmware/" directory.

c. In file "Firmware/config.h" set LANG_MODE to 0.

d. Run "Arduino IDE"; select the file "Firmware.ino" from the subdirectory "Firmware/" at the location, where you placed the source code File->Open Make the desired code customizations; all changes are on your own risk!

e. Select the target board "Tools->Board->PrusaResearch Einsy RAMBo"

f. Run the compilation Sketch->Verify/Compile

g. Upload the result code into the connected printer Sketch->Upload

  • or you can also save the output code to the file (in so called HEX-format) "Firmware.ino.rambo.hex": Sketch->ExportCompiledBinary and then upload it to the printer using the program "FirmwareUpdater"
    note: this file is created in the directory "Firmware/"

Using Linux subsystem under Windows 10 64-bit

notes: Script and instructions contributed by 3d-gussner. Use at your own risk. Script downloads Arduino executables outside of Prusa control. Report problems there. Multi language build is supported.

  • follow the Microsoft guide https://docs.microsoft.com/en-us/windows/wsl/install-win10 You can also use the 'prepare_winbuild.ps1' powershell script with Administrator rights
  • Tested versions are at this moment

    • Ubuntu other may different
    • After the installation and reboot please open your Ubuntu bash and do following steps
    • run command apt-get update
    • to install zip run apt-get install zip
    • add few lines at the top of ~/.bashrc by running sudo nano ~/.bashrc

    export OS="Linux" export JAVA_TOOL_OPTIONS="-Djava.net.preferIPv4Stack=true" export GPG_TTY=$(tty)

    use CRTL-X to close nano and confirm to write the new entries

    • restart Ubuntu bash Now your Ubuntu subsystem is ready to use the automatic PF-build.sh script and compile your firmware correctly

Some Tips for Ubuntu

  • Linux is case sensetive so please don't forget to use capital letters where needed, like changing to a directory
  • To change the path to your Prusa-Firmware location you downloaded and unzipped
    • Example: You files are under C:\Users\<your-username>\Downloads\Prusa-Firmware-MK3
    • use under Ubuntu the following command cd /mnt/c/Users/<your-username>/Downloads/Prusa-Firmware-MK3 to change to the right folder
  • Unix and windows have different line endings (LF vs CRLF), try dos2unix to convert
    • This should fix the "$'\r': command not found" error
    • to install run apt-get install dos2unix
  • If your Windows isn't in English the Paths may look different Example in other languages

    • English /mnt/c/Users/<your-username>/Downloads/Prusa-Firmware-MK3 will be on a German Windows/mnt/c/Anwender/<your-username>/Downloads/Prusa-Firmware-MK3

      Compile Prusa-firmware with Ubuntu Linux subsystem installed

  • open Ubuntu bash

  • change to your source code folder (case sensitive)

  • run ./PF-build.sh

  • follow the instructions

Using Git-bash under Windows 10 64-bit

notes: Script and instructions contributed by 3d-gussner. Use at your own risk. Script downloads Arduino executables outside of Prusa control. Report problems there. Multi language build is supported.

  • Download and install the 64bit Git version https://git-scm.com/download/win
  • Also follow these instructions https://gist.github.com/evanwill/0207876c3243bbb6863e65ec5dc3f058
  • Download and install 7z-zip from its official website https://www.7-zip.org/ By default, it is installed under the directory /c/Program\ Files/7-Zip in Windows 10
  • Run Git-Bash under Administrator privilege
  • navigate to the directory /c/Program\ Files/Git/mingw64/bin
  • run ln -s /c/Program\ Files/7-Zip/7z.exe zip.exe
  • If your Windows isn't in English the Paths may look different Example in other languages

    • English /mnt/c/Users/<your-username>/Downloads/Prusa-Firmware-MK3 will be on a German Windows/mnt/c/Anwender/<your-username>/Downloads/Prusa-Firmware-MK3
    • English ln -s /c/Program\ Files/7-Zip/7z.exe zip.exe will be on a Spanish Windows ln -s /c/Archivos\ de\ programa/7-Zip/7z.exe zip.exe

      Compile Prusa-firmware with Git-bash installed

  • open Git-bash

  • change to your source code folder

  • run bash PF-build.sh

  • follow the instructions

3. Automated tests


  • c++11 compiler e.g. g++ 6.3.1
  • cmake
  • build system - ninja or gnu make


Create a folder where you want to build tests.


cd ..

mkdir Prusa-Firmware-test

Generate build scripts in target folder.


cd Prusa-Firmware-test

cmake -G "Eclipse CDT4 - Ninja" ../Prusa-Firmware

or for DEBUG build:

cmake -G "Eclipse CDT4 - Ninja" -DCMAKE_BUILD_TYPE=Debug ../Prusa-Firmware

Build it.





4. Documentation

run doxygen in Firmware folder or visit https://prusa3d.github.io/Prusa-Firmware-Doc for doxygen generated output

5. FAQ

Q:I built firmware using Arduino and I see "?" instead of numbers in printer user interface.

A:Step 1.c was ommited or you updated Arduino and now platform.txt located somewhere in your user profile is used.

Q:I built firmware using Arduino and printer now speaks Klingon (nonsense characters and symbols are displayed @^#$&*°;~ÿ)

A:Step 2.c was omitted.

Q:What environment does Prusa use to build the firmware in the first place?

A:Our production builds are 99.9% equivalent to https://github.com/prusa3d/Prusa-Firmware#linux this is also easiest way to build as only one step is needed - run single script, which downloads patched Arduino from github, builds using it, then extracts translated strings and creates language variants (for MK2x) or language hex file for external SPI flash (MK3x). But you need Linux or Linux in virtual machine. This is also what happens when you open pull request to our repository - all variants are built by Travis http://travis-ci.org/ (to check for compilation errors). You can see, what is happening in .travis.yml. It would be also possible to get hex built by travis, only deploy step is missing in .travis.yml. You can get inspiration how to deploy hex by travis and how to setup travis in https://github.com/prusa3d/MM-control-01/ repository. Final hex is located in ./lang/firmware.hex Community reproduced this for Windows in https://github.com/prusa3d/Prusa-Firmware#using-linux-subsystem-under-windows-10-64-bit or https://github.com/prusa3d/Prusa-Firmware#using-git-bash-under-windows-10-64-bit .

Q:Why are build instructions for Arduino mess.

Y:We are too lazy to ship proper board definition for Arduino. We plan to swich to cmake + ninja to be inherently multiplatform, easily integrate build tools, suport more IDEs, get 10 times shorter build times and be able to update compiler whenewer we want.