Controlling device of turning knob and controlling method of touch panel

A turning knob control device, disposed on a touch panel removably to control the touch panel, the turning knob control device comprising:

• a base having a bottom side, a top side, a plurality of first pads, and at least two second pads, wherein the first pads are disposed at the bottom side, the at least two second pads are disposed at the top side, and the at least two second pads are electrically connected to corresponding parts of the first pads, the base is assembled to the touch panel with the bottom side, such that the first pads touch the touch panel;
• and
• a turning knob disposed on the top side of the base rotating about a rotating axis, the turning knob having a plurality of third pads facing the base and surrounding the rotating axis, when the turning knob rotates along a direction relative to the base, the third pads are electrically connected to the corresponding at least one of the second pads sequentially.