i am trying to burn a 1280 bootloader with my board at 8 MHz. I am getting this error saying "Yikes! Invalid device signature." when burning. I went into the boards.txt file and changed the cpu to mega.build.f_cpu=8000000L, Do the fuse numbers change also with change of clock speed? I am not sure what other settings i need to adjust.
I think you need to check the settings within avrdude.conf also for the signature bytes of the part you are using.
I was not sure how these bytes are determined, is there a way to see the output of avrdude is finding? I feel like the output in my console is very limited.
i am trying to burn a 1280 bootloader with my board
So I'm assuming you are using an Arduino as an ISP to burn the bootloader onto something else? Make sure what you are trying to burn the bootloader onto is actually the 1280. If it is then make sure you have every possible setting properly set. Fuses and everything. If that doesn't work then you may have to override the device signature check when burning with avrdude. I can't remember the exact parameter command but you can find it fairly easily in the avrdude terminal.
The signature bytes are from the ATMega1280 datasheet:
ATmega640 0x1E 0x96 0x08 ATmega1280 0x1E 0x97 0x03 ATmega1281 0x1E 0x97 0x04 ATmega2560 0x1E 0x98 0x01 ATmega2561 0x1E 0x98 0x02
Yes, i am using an arduino as ISP.
it says to use the -f flag to override it, however i am using the arduino burn bootloader option in the program, is there a way i can do this from the command line?
I don't know, I have not had luck doing stuff at the command line.I find it easier for later use to determine what's needed so it can be done automatically.