An electronic device includes a housing and a rotary switch received within the housing. The rotary switch includes a circuit board, a disk, a connecting shaft, and a pneumatic component. The connecting shaft protrudes from a central axis of the disk and connects to the circuit board. The pneumatic component is electrically coupled to the circuit board and includes an air chamber and a connecting rod. The connecting rod and the piston move together along the axis of the air chamber. The piston and the air chamber cooperatively define a sealed space. A circumference of the disk includes a number of protrusions. An engaging groove is defined between each two adjacent protrusions. A distance between a central axis of the disk and an inner wall of each engaging groove is different. The connecting rod selectively engages with a corresponding one of the engaging grooves.