can avrdude upload raw(hex) from arduino ?

question is in the title :wink:

i want to backup the original firmware of my 3Dprinter before upgrade it

thank you !

Yes. You can do that with avrdude, though not via the Arduino IDE. It's the same as the upload command, except with the -U option changed to:

-Uflash:r:filename.hex:i

More information:
https://www.nongnu.org/avrdude/user-manual/avrdude_4.html#Option-Descriptions