Pre-compiled hex output on PRUSA RESEARCH site: http://prusa3d.com/downloads/firmware/
Just download and flash it to the electronics
Install arduino
Remove Liquid Crystal library from your arduino or rename it
Install the arduino addon located in the root of this repo. Don't forget to install correct version!
Copy the configuration file matching your printer from variants folder to the the Firmware folder
Rename it to "Configuration_prusa.h"
Compile the firmware
Upload the firmware to board