Getting a .hex (or other compiled) file FROM a chip

Other Hardware 3rd Party Boards
1

I've searched for a while and cannot find a straight answer for this, hopefully someone can help me.

I basically have a programmed ATMega chip that I want to duplicate onto another ATMega of the same model.

I want to pull the hex file from the first chip onto the second chip as I do not have the source code for the chip.

I am pretty sure I can put the hex file onto the new chip, but I have no idea how to pull it from the first chip.

If anyone can help me I would really appreciate, I'm wracking my brain over this!

2

I'm assuming you have a programmer?

Using avrdude something like this:

avrdude -c usbtiny -p m328p -U flash:r:myfile.hex:i

You may need to change "usbtiny" to match your programmer type, and "m328p" to match your chip type.

The ":r:" near the end reads the flash and saves to myfile.hex.

To write this file to a new chip:

avrdude -c usbtiny -p m328p -U flash:w:myfile.hex

The ":r:" (read) has changed to ":w:" (write).

3

Thank you very much! I'm working off of a Sanguinololu board, I'm guessing I'll have to find supporting files before I can use AVRdude with it?

4

Thank you very much! I'm working off of a Sanguinololu board, I'm guessing I'll have to find supporting files before I can use AVRdude with it?

AVRDUDE through it's avrdude.conf file supports the 644P chip already so you shouldn't need any 'support files', just a hardware programmer that avrdude can work with.

Lefty

5

avrdude will do this, unless the flash in the source chip has been protected.
For reading flash to an intel hex file, it would look like:

    avrdude ... -U flash:r:myfile.hex:i

oops. Since I've been beaten to the punch, I'll point out that it SHOULD be possible to do this via the bootloader as well (which may well give you a .hex file that contains both sketch AND bootloader.)