Unlock the Power Prusa i3 MK2 Firmware and Flash

Last updated on December 24th, 2017 at 12:32 pm

Many in the past have wished to understand and flash their Prusa i3 MK2 with an unlocked version of the firmware and have access to unlimited features including custom tweaks and settings. Follow long in this video tutorial and get a grip on how it’s done. All the files you will need are available below the video.

In this download I have also made a couple additions that you may appreciate such as adding A Nylon Filament Preheat profile as well as Enabling The PID autotune feature you can run from the printers led screen. Select the temp you wish to auto tune for and after the autotune has completed it will save to eeprom automatically.

Fixed the issue where live z values were not properly saved resulting in an ever changing Z value forcing you to run the live z again and again.

In addition to the above changes I have also removed the oooozzzzing of filament when doing a filament change when the print head travels back to the part to print. 😉

Also added a few more materials to the preheat list.

Boards manager url to add to your preferences. Copy the url and paste it into the additional boards url: https://raw.githubusercontent.com/ultimachine/ArduinoAddons/master/package_ultimachine_index.json

Download the Prusa unlocked firmware and extract the files to your computer:

Download “Prusa i3 MK2 Un-Compiled Firmware” Prusa-Firmware-MK2.zip – Downloaded 561 times – 5 MB

Download and install the Arduino IDE software 1.8.2: https://www.arduino.cc/en/Main/Software

Follow along with the video below


look here for descriptions of G-codes: http://linuxcnc.org/handbook/gcode/g-code.html

If you only want to flash the new features but do not want to use Arduino

I have also made available an alternate version that is Pre Compiled and can be flashed with the Prusa Firmware Flasher. This version contains the Nylon Filament profile, Polypropylene profile as well as the added Autotune feature. Does not require Arduino ide simply flash it with the Prusa firmware flasher app available from Prusa in the Drivers Section.

Download “Pre Compiled Version” Prusa_MK2_Unlocked.zip – Downloaded 3841 times – 396 KB

Firmware Flasher included at Prusa Website in this area as illustrated below


Implemented Codes

P F – Returns FW versions
P R – Returns revision of printer
P Y – Starts filament allignment process for multicolor

G0 -> G1
G1 – Coordinated Movement X Y Z E
G4 – Dwell S or P
G10 – retract filament according to settings of M207
G11 – retract recover filament according to settings of M208
G28 – Home all Axis
G29 – Detailed Z-Probe, probes the bed at 3 or more points. Will fail if you haven’t homed yet.
G30 – Single Z Probe, probes bed at current XY location.
G31 – Dock sled (Z_PROBE_SLED only)
G32 – Undock sled (Z_PROBE_SLED only)
G80 – Automatic mesh bed leveling
G81 – Print bed profile
G90 – Use Absolute Coordinates
G91 – Use Relative Coordinates
G92 – Set current position to coordinates given

M Codes
M0 – Unconditional stop – Wait for user to press a button on the LCD (Only if ULTRA_LCD is enabled)
M1 – Same as M0
M17 – Enable/Power all stepper motors
M18 – Disable all stepper motors; same as M84
M20 – List SD card
M21 – Init SD card
M22 – Release SD card
M23 – Select SD file (M23 filename.g)
M24 – Start/resume SD print
M25 – Pause SD print
M26 – Set SD position in bytes (M26 S12345)
M27 – Report SD print status
M28 – Start SD write (M28 filename.g)
M29 – Stop SD write
M30 – Delete file from SD (M30 filename.g)
M31 – Output time since last M109 or SD card start to serial
M32 – Select file and start SD print (Can be used _while_ printing from SD card files):
syntax “M32 /path/filename#”, or “M32 S !filename#”
Call gcode file : “M32 P !filename#” and return to caller file after finishing (similar to #include).
The ‘#’ is necessary when calling from within sd files, as it stops buffer prereading
M42 – Change pin status via gcode Use M42 Px Sy to set pin x to value y, when omitting Px the onboard led will be used.
M80 – Turn on Power Supply
M81 – Turn off Power Supply
M82 – Set E codes absolute (default)
M83 – Set E codes relative while in Absolute Coordinates (G90) mode
M84 – Disable steppers until next move,
or use S to specify an inactivity timeout, after which the steppers will be disabled. S0 to disable the timeout.
M85 – Set inactivity shutdown timer with parameter S. To disable set zero (default)
M92 – Set axis_steps_per_unit – same syntax as G92
M104 – Set extruder target temp
M105 – Read current temp
M106 – Fan on
M107 – Fan off
M109 – Sxxx Wait for extruder current temp to reach target temp. Waits only when heating
Rxxx Wait for extruder current temp to reach target temp. Waits when heating and cooling
IF AUTOTEMP is enabled, S B F. Exit autotemp by any M109 without F
M112 – Emergency stop
M114 – Output current position to serial port
M115 – Capabilities string
M117 – display message
M119 – Output Endstop status to serial port
M126 – Solenoid Air Valve Open (BariCUDA support by jmil)
M127 – Solenoid Air Valve Closed (BariCUDA vent to atmospheric pressure by jmil)
M128 – EtoP Open (BariCUDA EtoP = electricity to air pressure transducer by jmil)
M129 – EtoP Closed (BariCUDA EtoP = electricity to air pressure transducer by jmil)
M140 – Set bed target temp
M150 – Set BlinkM Color Output R: Red U(!): Green B: Blue over i2c, G for green does not work.
M190 – Sxxx Wait for bed current temp to reach target temp. Waits only when heating
Rxxx Wait for bed current temp to reach target temp. Waits when heating and cooling
M200 D- set filament diameter and set E axis units to cubic millimeters (use S0 to set back to millimeters).
M201 – Set max acceleration in units/s^2 for print moves (M201 X1000 Y1000)
M202 – Set max acceleration in units/s^2 for travel moves (M202 X1000 Y1000) Unused in Marlin!!
M203 – Set maximum feedrate that your machine can sustain (M203 X200 Y200 Z300 E10000) in mm/sec
M204 – Set default acceleration: S normal moves T filament only moves (M204 S3000 T7000) in mm/sec^2 also sets minimum segment time in ms (B20000) to prevent buffer under-runs and M20 minimum feedrate
M205 – advanced settings: minimum travel speed S=while printing T=travel only, B=minimum segment time X= maximum xy jerk, Z=maximum Z jerk, E=maximum E jerk
M206 – set additional homing offset
M207 – set retract length S[positive mm] F[feedrate mm/min] Z[additional zlift/hop], stays in mm regardless of M200 setting
M208 – set recover=unretract length S[positive mm surplus to the M207 S*] F[feedrate mm/sec]
M209 – S<1=true/0=false> enable automatic retract detect if the slicer did not support G10/11: every normal extrude-only move will be classified as retract depending on the direction.
M218 – set hotend offset (in mm): T X Y
M220 S- set speed factor override percentage
M221 S- set extrude factor override percentage
M226 P S- Wait until the specified pin reaches the state required
M240 – Trigger a camera to take a photograph
M250 – Set LCD contrast C (value 0..63)
M280 – set servo position absolute. P: servo index, S: angle or microseconds
M300 – Play beep sound S P
M301 – Set PID parameters P I and D
M302 – Allow cold extrudes, or set the minimum extrude S.
M303 – PID relay autotune S sets the target temperature. (default target temperature = 150C)
M304 – Set bed PID parameters P I and D
M400 – Finish all moves
M401 – Lower z-probe if present
M402 – Raise z-probe if present
M404 – N Enter the nominal filament width (3mm, 1.75mm ) or will display nominal filament width without parameters
M405 – Turn on Filament Sensor extrusion control. Optional D to set delay in centimeters between sensor and extruder
M406 – Turn off Filament Sensor extrusion control
M407 – Displays measured filament diameter
M500 – stores parameters in EEPROM
M501 – reads parameters from EEPROM (if you need reset them after you changed them temporarily).
M502 – reverts to the default “factory settings”. You still need to store them in EEPROM afterwards if you want to.
M503 – print the current settings (from memory not from EEPROM)
M509 – force language selection on next restart
M540 – Use S[0|1] to enable or disable the stop SD card print on endstop hit (requires ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED)
M600 – Pause for filament change X[pos] Y[pos] Z[relative lift] E[initial retract] L[later retract distance for removal]
M605 – Set dual x-carriage movement mode: S [ X R ]
M907 – Set digital trimpot motor current using axis codes.
M908 – Control digital trimpot directly.
M350 – Set microstepping mode.
M351 – Toggle MS1 MS2 pins directly.

M928 – Start SD logging (M928 filename.g) – ended by M29
M999 – Restart after being stopped by error

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