For anyone building theSlowGrowth’s Monome Arc clone project, here are the avrdude commands required to set the ATMega88p fuses, based on this fuse calculation:

avrdude -V -p m88p -c YOUR_PROGRAMMER_ID -P YOUR_PROGRAMMER_PORT -B 10 -e -u -U lfuse:w:0xD6:m -U hfuse:w:0xDF:m -U efuse:w:0xF9:m -U lock:w:0xFF:m

and then flashing the precompiled firmware is pretty straightfoward. USB board: (swap arc4_ for arc2_ in the unlikely event you’re building an arc2):

avrdude -V -p m88p -c YOUR_PROGRAMMER_ID -P YOUR_PROGRAMMER_PORT -B 2 -U flash:w:./firmware/compiled_hex/arc4_firmware_usb_board_atmega88p.hex:i -U lock:w:0xFF:m

and for each ring:

avrdude -V -p m88p -c YOUR_PROGRAMMER_ID -P YOUR_PROGRAMMER_PORT -B 2 -U flash:w:./firmware/compiled_hex/firmware_pot_board_atmega88p.hex:i -U lock:w:0xFF:m

Note that the verion of avrdude I’m using (5.8, from an old crosspack install I was using to compile some MI AVR code) doesn’t support the ATMega88p, and in order for any of this to work, you may need to edit the avrdude config file according to the instructions in the arc clone repo. Mine was in /usr/local/CrossPack-AVR-20100115/etc/avrdude.conf, and all I had to do was duplicate the config block for the ATMega88 and make the following changes:

id               = "m88p";
desc             = "ATMEGA88P";

and

signature        = 0x1e 0x93 0x0f;