Go to http://www.prusa3d.com/drivers/ and download latest PRUSA3D drivers.
  • Go to http://www.prusa3d.com/drivers/ and download latest PRUSA3D drivers.

  • Install drivers on your Windows or MacOS system.

  • Part of the drivers package is software for firmware upgrade.

In Step 1 Download necessary software

The instruction “Install drivers on your Windows or MacOS system” is not sufficient for MacOS. After downloading, the folder “prusa3d_mac_2_1_4” is left in the Downloads folder. Apparently it needs to be manually moved to the Applications folder to complete the installation.

Bill Waring - Reply

Go to http://www.prusa3d.com/drivers/ and scroll down to the Firmware section. Always look for the firmware prepared for your printer! Download the zip file with the firmware to your computer and unzip it.
  • Go to http://www.prusa3d.com/drivers/ and scroll down to the Firmware section.

  • Always look for the firmware prepared for your printer!

  • Download the zip file with the firmware to your computer and unzip it.

  • Use enclosed guide to select the correct firmware according to the version of your RAMBO board.

Add Comment

Connect your printer to the computer using provided USB cable and turn the printer on.
  • Connect your printer to the computer using provided USB cable and turn the printer on.

  • Launch the FirmwareUpdater application.

  • Choose your firmware .*hex file.

  • Choose serial port of your printer.

  • If you don't see your printer on the left, hit this button and wait around 2 seconds.

  • Hit the Update! button.

  • Monitor the status of updating.

  • Update process may take up to 5 minutes.

FirmwareUpdater? Can you please specify the exact file and relative path to it ? When I unzipped the firmware only c++ source files, headers and a make files were unzipped. There was no FirmwareUpdater.exe to run.

I was expecting to see the .exe in this folder but there is non.


Please advise

TimOdell - Reply

I found it under C:\Program Files\Prusa3D\Utilities.

pgiustino -

Hey GNU/Linux users:

Head on over to Update RAMBo mini firmware (OLD method) for how to upgrade. There will be instructions in the comments there, step by step.

PappaD - Reply

Sorry PappaD, I could not follow these steps. The "rambo" folder from step 2 is no where to be found. Instead, I did:

1. sudo apt-get install avrdude

2. sudo avrdude -c stk500v2 -b 115200 -p Atmega2560 -v -P /dev/ttyACM0 -D -U 1_75mm_MK2-RAMBo13a-E3Dv6full.hex

Gael Lafond -

I don't see the printer. Only COM 4 - and I am not able to press Update.

Arno - Reply

hours and hours no upgrade

no lcd display

Joseph Mwadime - Reply

Just open Pronterface and try to connect to diferent COM ports first. If it connects, then its correct.

Vallo - Reply

hi i have this Error: EPERM, open 'C:\Program Files\Prusa3D\Utilities\fw.hex'

when i want to upgrade with the lastest utilities

slim -

This helped me! First open Pronterface i had to change the Baudrate to "115200" after that sucessful connection. Disconnect and try the update again, it worked

Hans Inauen -

I am not able to see the printer on any COM port even after hitting the Recan button. This is after installing the latest driver, Version 1.7.5. Is this an OS and COM issue or an issue with the Firmware updater v2. I also restarted my machine after installing the driver.

Jonathan Arteaga - Reply

Using Pronterface I was able to see that the printer was on COM 4 and could connect to the printer. I can now adjust the axes from Pronterface. However a firmware update did not work using COM4. After a Rescan I do not see the printer name in the drop-down list, just COM 4.

Jonathan Arteaga -

I disconnected from Pronterface. Relaunched firmware updater v2. Selected COM4 even though it was not recognized by name as the Prusa. Hit the Update button. No status indication aside from "update in progress" like Mark Jurisch noted in Step 4. After about 1 minute I got a successful update and confirmed firmware 3.0.9 on the Prusa LCD menu. This should be a bit easier to do. Thanks everyone for comments. I hope my comments help too.

Jonathan Arteaga -

Going to device manager worked for me - showed a mapping of printer to COM 3

Keith Mizen - Reply

Connected fine through COM3 via Pronterface. In firmware updater, upon choosing COM3 and selecting the .hex file (1_75mm_MK2-RAMBo13a-E3Dv6full.hex), I got the following error when I clicked update: "avrdude.exe: ser_open(): can't open device "\\.\COM3": Access is denied. avrdude.exe: ser_drain(): read error: The handle is invalid. avrdude.exe: ser_send(): write error: sorry no info avail avrdude.exe: stk500_send(): failed to send command to serial port avrdude.exe: ser_recv(): read error: The handle is invalid. avrdude.exe: stk500v2_ReceiveMessage(): timeout avrdude.exe: ser_send(): write error: sorry no info avail avrdude.exe: stk500_send(): failed to send command to serial port".

Based on Jonathan's advice, I closed Pronterface (which I'd forgotten I'd left open), stopped and restarted the Firmware Updater and the next attempt worked fine.

Greg Boyd - Reply

If you get a "node.js" error when using the "FirmwareUpdaterV2" included in the 1.7.5 package, try the "FirmwareUpdater" included in the 1.7.4 package. Worked for me. [Me: macOS Sierra 10.12.3 going to FW-3.0.10]

Tim Fou - Reply

Why isn’t there a status / progress view? This would help a lot…

Manus van den Berg - Reply

Hi Manus, you are right and progress bar might be included in the future releases.

Jakub Dolezal -

There is no “Firmware Updater Application” for Linux. Please provide explicit instructions for Linux, especially for MK3, since there are some Rambo-specific instructions somewhere.

Alex Emelianov - Reply

Hi Alex, I will talk to firmware developers and let you know ;)

Jakub Dolezal -

Tried to update without Pronterface , this is the result:

avrdude.exe: AVR device initialized and ready to accept instructions Reading | ################################################## | 100% 0.01s avrdude.exe: Device signature = 0x1e9801 (probably m2560) avrdude.exe: reading input file "./fw.hex" avrdude.exe: can't determine file format for ./fw.hex, specify explicitly avrdude.exe: read from file './fw.hex' failed avrdude.exe done. Thank you.

Is it nesseccary to use Pronterface? Restarting the updater didn’t work either. What else can I do?

André Panzer - Reply

The Connection with Pronterface works without a Problem (com3). The Updater still tells me the same. Any tips?

André Panzer -

On my MacBookPro, “Step 1: Choose *.hex file to flash:” required me to search through my system files until I located the Downloads folder and found “prusa3d_fw_3_1_3_mks.hex”. After that the installation went very smoothly. Thank you!

Note: for “Step 2: Choose serial port:” the Firmware updater automatically selected “/dev/tty.usbmodem1421” which really helped. Us Mac folks don’t normally have to worry about selecting serial ports.

Bill Waring - Reply

Congratulations, now you have successfully updated firmware in your printer, HAPPY PRINTING!
  • Congratulations, now you have successfully updated firmware in your printer, HAPPY PRINTING!

The output doesn't give any indication of progress, or even if a connection was made on the COM port. Some indication of status beyond "update in progress, don't touch anything" would be nice, especially when it isn't working and sits on that screen until you exit the program without an error or indication it wasn't working.

Mark Jurisch - Reply

I agree, any hint as to how long this should take? Is it safe to exit if nothing seems to happen after x amount of time?

Maarten Knapen - Reply

Tried several times to download the zip file from the drivers page, no success despite different computers, mobile, etc etc no other network problems and Prusa support not offering any meaningful solution other than get someone else to download it, seriousy???

Foster Plender - Reply

Hi Foster, I'm sorry for the troubles you had. Did you manage to download the drivers?

Jakub Dolezal -

Can we get a ballpark figure of how long an update should take?

Arash Outadi - Reply

Hi Arash, the update shouldn't take more than few minutes (up to 5 minutes).

Jakub Dolezal -

Took about 3 minutes to update for me

Allen Weaver - Reply

I got a long error about avrdude.exe timeouts. I connected the computer that are doing the update to the internet and tried again. Then it worked. Took about 3 minutes.

Martin Jørgensen - Reply

Hi Martin, interesting observation with the Internet connection. Most of the issues are caused by assigned port in the Device Manager and Firmware updater. (Step 5 in this guide)

Jakub Dolezal -

Having nothing but problems, issues and frustration in trying to get my HP with Windows 10, to update anything!!!

The Device Manager doesn’t have the ‘firmware updater’ as an option, nor the “choose serial port” as an option.

Does your usb cord work with the 3.0 USB???

My PC can see the printer in it’s settings.

I don’t know, perhaps I should just sell this %#*@ thing on EBAY!

Deb Elder - Reply

This stupid machine is really !#^&^$^ me off…just saying! Been dicking around with this for 3 hours now!!!

My HP Windows 10 can see it in my settings file.

The Device Manager sees it, but doesn’t offer the COM drop down window like you show.

Firmware updater never comes up as an option…

I go to launch the updates and the system asks ‘which program do you want to open this with?’

I’ve no idea which application to use, as none I’ve tried work.

Does your cord work with 3.0 USB ports???

Have to say, if everything with this printer is this difficult, I’m gonna put it on EBAY and move on.

Call me to prevent that: 541-854-5336 and let’s fix this.

Deb Elder - Reply

Hi Deb, let’s fix this, please do following:

1) Download and install the latest drivers package and ENSURE the printer drivers are installed (you will prompted to install them)

2) Try at least two different ports (and yes USB 3.0 should be ok, I'm flashing printers from brand new laptop)

3) If you can't see the printer in Device Manager, go to control panels, uninstall the package, reboot and install again

4) If the issue still persists, please use our live-chat, one of my colleagues from support team will help you in real-time ;)

Jakub Dolezal -

In general updating the firmware using my Mac was not really difficult. Of course I’m somewhat spoiled by the excellent Assembly Manual that came with my MK3 kit. Thanks Jakub.

Bill Waring - Reply

On Windows 10 it might happen the system sets different port in the Firmware updater and in the Device Manager.
  • On Windows 10 it might happen the system sets different port in the Firmware updater and in the Device Manager.

  • Open your Device Manager, check the assigned port and set it on the Firmware updater.

  • Hit the Update! button

  • If the port isn't listed in the Firmware Updater, hit the Rescan button several times.

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Josef Prusa

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GNU/Linux Users, you can upload hex file using avrdude.

- Install arduino from your distro repos (Tested on Ubuntu 12.04)

- Download your new firmware for your board from: http://www.prusa3d.com/drivers/

- Extract

- Open a terminal and cd to extracted dir

- Upload by running (Change "3mm-RAMBo13a-PrusaNmk2.hex" to your board and extruder):

/usr/share/arduino/hardware/tools/avrdude -C/usr/share/arduino/hardware/tools/avrdude.conf -v -patmega2560 -cstk500v2 -P/dev/ttyACM0 -b115200 -D -Uflash:w:3mm-RAMBo13a-PrusaNmk2.hex:i

Alejandro Romero - Reply

Under Linux I flashed the firmware .hex file with avrdude:

avrdude -c stk500v2 -b 115200 -p Atmega2560 -v -P /dev/ttyACM0 -D -U 1_75mm_MK2-RAMBo13a-E3Dv6full-3.0.8.hex

Even better would be compiling the firmware myself, but so far the Arduino project didn't want to be built..

Jonas Jelten - Reply

I confirm it is working with avrdude on OSX too. Just uploaded doing: avrdude -c stk500v2 -b 115200 -p Atmega2560 -v -P /dev/tty.usbmodemFA131 -D -U 1_75mm_MK2-RAMBo13a-E3Dv6full.hex

To install avrdude: brew install avrdude --with-usb

Denis Pitzalis - Reply

You guys saved me here!....

With standard Arduino software install I was able to do:

$ pwd


$ ./avrdude -C ../etc/avrdude.conf -P /dev/tty.usbmodem1421 -b115200 -D -Uflash:w:/Applications/Prusa3d/prusa3d_mac_1_7_5/1_75mm_MK2-RAMBo13a-E3Dv6full.hex -v -patmega2560 -cstk500v2

and now my printer is back to normal...

Devon Heron - Reply

Anybody get continuous timeout messages doing this? This is from a Raspberry Pi running OctoPrint. I did hit the "disconnect" button in the OctoPrint web interface to try to prevent port conflicts.

pi@octopi:~ $ avrdude -c stk500v2 -b 115200 -p Atmega2560 -v -P /dev/ttyACM0 -D -U flash:w:1_75mm_MK2-RAMBo13a-E3Dv6full.hex:i

avrdude: Version 6.1, compiled on Jul 7 2015 at 10:29:47

Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/

Copyright (c) 2007-2014 Joerg Wunsch

System wide configuration file is "/etc/avrdude.conf"

User configuration file is "/home/pi/.avrduderc"

User configuration file does not exist or is not a regular file, skipping

Using Port : /dev/ttyACM0

Using Programmer : stk500v2

Overriding Baud Rate : 115200

avrdude: stk500v2_ReceiveMessage(): timeout

avrdude: stk500v2_ReceiveMessage(): timeout

avrdude: stk500v2_ReceiveMessage(): timeout

Henry Berg - Reply

I am getting this error:

Uncaught node.js Error

Error: EROFS, open '.fw.hex' at Error(native)

I am running Mac 10.12.3

I happen to have Node v4.6.2 installed

Richard Yee - Reply

Same error as @RichardYee, same Mac OS version 10.12.3, node version v5.10.0. What is the resolution?

Soumitra Kumar - Reply

I am also seeing the same Error: open 'fw.hex' message as mentioned above. On macOS 10.12.3, node v6.9.1.

Joe Fiorini - Reply

I tried the FirmwareUpdater on Win10 but the utility was unable to locate any com ports. I tried various thing spending almost a day until I found solution:

1) Remove the PRUSA 3D printer drivers in control panel, under printers & devices.

2) Remove all remaining PRUSA related software in control panel, under Programs and functions.

3) Turned off PRUSA i3 Mk2 and rebooted PC

4) Downloaded 1.7.6 windows drivers and installed them, using RMB and selecting Run as ADMINISTRATOR

5) Turned on PRUSA i3 Mk2

Now the Firmwareupdater found the COM ports and I could update firmware.

Per Hassel Sørensen - Reply

I had a problem with the FirmwareUpdater on macOS, so I just used avrdude as recommended in the comments. I did have to make one change though. After installing with brew install avrdude, the command I used was:

avrdude -c avrispmkII -b 115200 -p Atmega2560 -v -P /dev/tty.usbmodemXXXX -D -U 1_75mm_MK2-RAMBo13a-E3Dv6full.hex

You will need to look at what /dev/ device you should use. Try ls /dev/tty.usbmodem* to see it.

Andrew Willis - Reply

On linux I use Cura to load the FW file. Quick, easy, without problems.

In avrdude I had an error "avrdude error: stk500v2_ReceiveMessage (): timeout"

Łukasz Zep - Reply

I had to disconnect then delete my printer from the windows 10 settings page plug it back in again. Check its actually connects using Pronterface then run the Firmware updater which doesn't list my printer just Com3 comes up worked fine after that

Neil Winstanley - Reply

Do I have to check the Use relative E distances box in the prusa edition Slic3r?

Joaquin Otero - Reply

Hi Joaquin, "Use relative E distances" is checked by default. This thread is dedicated to the firmware update, next time please use the right section, our forums or support, thanks :)

Jakub Dolezal -

My os is Linux Mint 18.1. I used cura 3.1.0 for update to MK3 firmware 3.1.1.-RC5.

Update was easy, unzip, select hex file in cura “upload user defined firmware”. Selected printer was prusa MK2.

Meteor42 - Reply

The Prusa 3D Printing Handbook (from https://www.prusa3d.com/downloads/manual... ) says that “First Layer Calibration ​is required after the firmware update“. Why isn’t this mentioned here also?

Kari Söderholm - Reply

Hi Kari, “first layer calibration” isn’t required after each firmware update. I will talk to my colleagues responsible for the Handbook to correct it.

Jakub Dolezal -

Upgraded successfully on Debian using avrdude, calibration didn’t run on reboot so I started it manually. Everything was fine until first layer calibration at which point it repeatedly failed on point 8. I couldn’t find any reason for this however a factory reset and starting the calibration wizard over fixed this. Thanks for the update :-)


Tom Hinkley - Reply

Can someone please help me? I have installed the new firmware as instructed, and now our Prusa MK2 is not responding, only turns on to a blank screen. I have tried a hard reboot and resetting to older version of the firmware. Please help we are hosting the 3D printer as part of a traveling technologies bundle for our area libraries.

Thanks Crystal

Crystal Vargas - Reply

Hi Crystal, blank screen might be some HW issue, please visit shop.prusa3d.com and look for the live chat button.

Jakub Dolezal -

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