Patent ID: 8909173

Claim:
An interface system, comprising: a radio having a controller; a remote accessory having a memory device with accessory configuration data stored therein; a single signal line for controlling three accessory functions between the radio controller and the remote accessory, the single signal line being pulled high when no remote accessory is attached to the radio, the single signal line being pulled to a first predetermined voltage in response to the remote accessory being attached to the radio indicating an accessory detection function, the controller reading the accessory configuration data over the single signal line in response to the remote accessory being detected, and the single signal line being pulled to a second predetermined voltage in response to push-to-talk (PTT) presses; a first comparator in the radio for detecting attachment of the remote accessory; and a second comparator in the radio for detecting accessory PTT presses after the accessory configuration data of the memory device has been read.