Abstract: A peripheral apparatus, for connecting to a first or a second transmission port of an electronic device, includes a signal transmission interface, a triggering unit, an amplifying unit and an adjusting unit. The signal transmission interface, coupled to the first or the second transmission port, includes a first and a second group of pins. The triggering unit is coupled to the signal transmission interface. When the signal transmission interface is coupled to the first or the second transmission port, the triggering unit outputs a first or a second voltage level signal, respectively. The amplifying unit is coupled to the signal transmission interface and a functional unit. The adjusting unit, coupled to the signal transmission interface, the triggering unit, the amplifying unit and the functional unit, changes an output power transmitted from the amplifying unit to the functional unit according to the first or the second voltage level signal.

Abstract: An optical multi-touch method of a window interface is adapted to control an object in the window interface. The method includes providing a first optical sensing window to obtain a first tracking signal and providing a second optical sensing window to obtain a second tracking signal; resolving the first tracking signal to determine a first displacement direction and resolving the second tracking signal to determine a second displacement direction; and controlling a motion of the object in the window interface according to a relative relation between the first displacement direction and the second displacement direction.