I've read Gordon's blog pages and used the instructions on http://rasp.io/duino/ on the way to setting up my own Raspberry Pi and ATmega328 board but I've run into a problem that I have yet to see a solution to.
Fuses are programmed on the ATmega328 and Arduino IDE launched. The 'Serial Port' menu option is greyed out. The pi user is a member of the tty group.
Several forum posts talk about creating a symlink from /dev/ttyUSB0 to /dev/ttyAMA0 (which exists). I tried this and although it resulted in the menu option being enabled, attempts to use the Arduino Serial Monitor resulted in the following error...
java.io.Exception: Inappropriate ioctl for device in nativeavailable
at gnu.io.RXTXPort.nativeavailable(Native Method)
I checked the file /boot/cmdline.txt and it still contains 'console' settings but no tty/AMA0 params...
dwc_otg.lpm_enable=0 console=serial0,115200 root=/dev/mmcblk0p7 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait
Perhaps I should remove the 'console=serial0' part but I'm not certain. /etc/inittab is empty but "inappropriate ioctl" suggests to me that ttyAMA0 and ttyUSB0 are somehow incompatible. Suggestions gratefully accepted.