ROTATABLE INPUT KNOB CONFIGURED TO OPERATE ON ELECTROSTATIC CAPACITIVE TOUCH PANEL

According to one embodiment, a sensor device includes an electrostatic capacitive touch panel, a knob disposed rotatably about a rotation axis, a conductor held by the knob and opposed to the touch panel on a part of a circumference about the rotation axis, and a sensor controller which controls the touch panel. The sensor controller holds a reference signal corresponding to an electrostatic capacitance in a state where the conductor is not opposed to the touch panel, and detects first coordinates of the conductor based on a first sensor signal received from the touch panel in a state where the conductor is opposed to a first position of the touch panel and the reference signal in a first sensing period.