Just my own adaptation for mass storage sd card and keyboard for AT90USBKEY2.
ported from Mathieu Sonet lufa-sdcard-mass-storage-demo USB Mass storage on SD card with a Teensy2/ATMEGA32U4 to AT90USBKEY2
https://bitbucket.org/elasticsheep/lufa-sdcard-mass-storage-demo/src/default/
ported from LUFA091223 to LUFA170418
http://www.fourwalledcubicle.com/LUFA.php
ported from MMC/SD/SDHC card reader library to FatFS:
http://www.roland-riegel.de/sd-reader/index.html
http://elm-chan.org/fsw/ff/00index_e.html
There are two demo projects:
LUFA standard DEMO project: lufa-sdcard-mass-storagekeyboard-fatfs-AT90USBKEY2\lufa-sdcard-mass-storagekeyboard-fatfs-AT90USBKEY2\Demos\Device\ClassDriver\MassStorageKeyboard
Already compiled .hex:
lufa-sdcard-mass-storagekeyboard-fatfs-AT90USBKEY2\lufa-sdcard-mass-storagekeyboard-fatfs-AT90USBKEY2\Demos\Device\ClassDriver\MassStorageKeyboard\MassStorageKeyboard.hex
Atmel Studio 7 project (for user-friendly JTAG debug): lufa-sdcard-mass-storagekeyboard-fatfs-AT90USBKEY2\mass_storagesd_keyboard_atmel\mass_storagesd_keyboard_atmel.atsln
Already compiled .hex:
lufa-sdcard-mass-storagekeyboard-fatfs-AT90USBKEY2\mass_storagesd_keyboard_atmel\mass_storagesd_keyboard_atmel\Debug\mass_storagesd_keyboard_atmel.hex
lufa-sdcard-mass-storagekeyboard-fatfs-AT90USBKEY2\mass_storagesd_keyboard_atmel\mass_storagesd_keyboard_atmel\Release\mass_storagesd_keyboard_atmel.hex