Arduino Pro Nano prepare brew install avrdude read (from old) avrdude -patmega328p -carduino -P/dev/cu.usbserial-AH05Q2H6 -b57600 -D -Uflash:r:/tmp/sketch1.hex:i write (to new) avrdude -patmega328p -carduino -P/dev/cu.usbserial-AH05Q2H6 -b57600 -D -Uflash:w:/tmp/sketch1.hex:i