According to various embodiments, there is provided a user input device including: a chassis including a socket configured to releasably receive a panel; a memory storing a plurality of button maps, wherein each button map of the plurality of button maps defines functions of at least one button of a respective panel of a plurality of panels, each of which being receivable in the socket; and a processor configured to read an identity code of the received panel, and further configured to identify a matching button map from the plurality of button maps based on the identity code, wherein the matching button map defines the functions of the at least one button of the received panel.