I found out how to program the rainbowduino with my buspirate (updated the wiki as well) but that involves removing the rainbowduino from my cube and replacing it after programming. I prefer to be able to use the bootloader for programming. Problem is that I erased the chip and so did also erase the bootloader (I assume).
I found ‘optiboot’ and tried to upload it to the rainbowduino.
That was successful but what are the fuse settings for the rainbowduino?
And what bootloader should I actually use on the rainbowduino?