ADC2 and ADC3 channels do not exist on the U4 series USB AVRs.
drwxr-xr-x - Bootloaders
drwxr-xr-x - Demos
-rw-r--r-- 59032 LUFA.pnproj
drwxr-xr-x - LUFA
drwxr-xr-x - Projects
-rw-r--r-- 1330 README.txt
-rw-r--r-- 978 makefile