Format of Keys and ID's for Arduino LMIC library

The question now and then rises with new users so I put this information into a separate topic.

When using the Arduino LMIC library use the following formats for your keys and ID’s:

Key/ID Description Format C++ type Use for activation type
DevEUI end-device identifier lsb / little-endian u1_t[8] OTAA
AppEUI application identifier lsb / little-endian u1_t[8] OTAA
AppKey application key msb / big-endian u1_t[16] OTAA
DevAddr end-device address u4_t ABP
NwkSKey network session key msb / big-endian u1_t[16] ABP
AppSKey application session key msb / big-endian u1_t[16] ABP


lsb: least significant byte first
msb: most significant byte first