A control method, suitable for a controller in an interface device having capacitive sensors, includes following steps. The capacitive sensors are arranged on a plane. During a first period, the controller is configured to set the capacitive sensors as self-capacitance sensors individually. During a second period, the controller is configured to divide the capacitive sensors into at least a first group and a second group, set the first group of capacitive sensors as a mutual-capacitance transmitter and generate a pulse signal to the mutual-capacitance transmitter, set the second group of capacitive sensors as a mutual-capacitance receiver and collect a sensing signal from the mutual-capacitance receiver in response to the pulse signal.