Patent ID: 8078223

Claim:
A mobile terminal comprising: a main body configured to provide a communication function; an expansion module configured to provide a number of additional functions to the main body; a connector including at least first, second and third pins and configured to electrically connect the main body and the expansion module together; and a controller configured to determine whether a signal having a first logic level is received via the first pin of the connector, to set up communication between the mobile terminal and the expansion module using only the first pin and a corresponding ground source and a 1-wire communication method on the first pin if the signal received on the first pin has the first logic level, to determine whether or not the expansion module is an authenticated expansion module through the 1-wire communication method on the first pin, and to allow the expansion module to provide the number of additional functions to the main body through serial communication using the second and third pins when the expansion module is determined to be successfully authenticated.