so i need to program the MAX3421E chip with arduino , but i cannot use the full library .
all i need is to communicate with a keyboard or a mouse (HID) .
due to the library being filled with classes and stuff , taking just the right stuff out of it , is not that easy .
i would've used google , but cant really figure where to start exactly or where is the shortest part .
the SPI part is all covered , what i want to know is either how the protocol exactly works , or what should i look for for these exact devices keyb and mouse .
but i cannot use the full library .
Why not? Only the code that you actually used will be part of the resulting HEX file.
Or switch to one of the Arduinos which have the USB built-in, like the Micro or Teensy. Then you don't need the library to talk to the USB chip.