For further experiments, I'm trying to compile the firmware within the Arduino IDE.
I went to GitHub and grabbed the RepRapFirmware files. I renamed the folder into RepRapFirmware. I also downloaded Arduino-libraries from GitHub and added those files to the RepRapFirmware folder. Trying to compile in Arduino IDE, I'm still getting "fatal error: utility/compiler.h: No such file", even if the file is there?
Can anyone help, please?