avrdude - romain145/grbl GitHub Wiki
Flashing a firmware (typically the bootloader) with AVR ISP mkII programmer : sudo avrdude -c avrispmkII -P usb -p atmega644p -U flash:w:ATmegaBOOT_644P.hex:i
Flashing a firmware with bootloader : avrdude -c arduino -P /dev/ttyUSB0 -b 9600 -D -p atmega644p -U flash:w:grbl.hex:i
The root can be avoided by adding a rule to udev : http://stackoverflow.com/questions/5412727/avrisp-mkii-doesnt-work-with-avrdude-in-linux
Create new file /etc/udev/rules.d/60-avrisp.rules
SUBSYSTEM!="usb_device", ACTION!="add", GOTO="avrisp_end"
# Atmel Corp. JTAG ICE mkII
ATTR{idVendor}=="03eb", SYSFS{idProduct}=="2103", MODE="660", GROUP="dialout"
# Atmel Corp. AVRISP mkII
ATTR{idVendor}=="03eb", SYSFS{idProduct}=="2104", MODE="660", GROUP="dialout"
# Atmel Corp. Dragon
ATTR{idVendor}=="03eb", SYSFS{idProduct}=="2107", MODE="660", GROUP="dialout"
LABEL="avrisp_end"
Check you're in the dialout group
groups
Unplug and replug the AVR ISP mkII