Abstract: An electronic device includes a housing defining an opening, a circuit board fixed in the housing, a processor, and a wheel module. The wheel module includes a seat, a cantilevered arm, a wheel rotatably fixed to the cantilevered arm and partially extending out of the opening, an encoder fixed to the cantilevered arm, and a micro switch fixed to the seat. One end of the cantilevered arm is fixed to the seat, and an opposite end is free. The cantilevered arm is deformable so as to enable the free end to actuate the micro switch, when the cantilevered arm is depressed. The actuated micro switch then generates a trigger signal. The encoder is configured to convert the rotation of the wheel to corresponding electrical signals, when the wheel is rotated. The processor controls the electronic device to perform preset functions according to the trigger signal or the electrical signals.