Sensor controller, electronic device, and control method of sensor controller

An electronic device comprising:

• a touch sensor including a plurality of detection electrodes arranged in a plane, wherein the touch sensor, in operation, detects a position of a passive pointer;
• and
• a sensor controller including:
• a transmission circuit connected to the touch sensor, wherein the transmission circuit, in operation, transmits a transmission signal to the touch sensor in a plurality of third periods, each of the third periods including a first period for measuring electromagnetic noise and a second period for detecting the position of the passive pointer;
• a processor;
• and
• a memory storing a program that, when executed by the processor, causes the processor to:
• measure a level of electromagnetic noise at a frequency associated with the first period and a level of electromagnetic noise at a frequency associated with the second period, and
• select, as a scan frequency of the transmission signal in the second period, the frequency associated with the first period or the frequency associated with the second period according to a measurement result of the level of the electromagnetic noise at the frequency associated with the first period and the level of the electromagnetic noise at the frequency associated with the second period.

A control method of a sensor controller that controls an operation of a touch sensor detecting a position of a passive pointer, the control method comprising:

• transmitting a transmission signal to the touch sensor in a plurality of third periods, each of the third periods including a first period for measuring electromagnetic noise and a second period for detecting the position of the passive pointer;
• measuring a level of electromagnetic noise at a frequency associated with the first period and a level of electromagnetic noise at a frequency associated with the second period;
• and
• selecting, as a scan frequency of the transmission signal in the second period, the frequency associated with the first period or the frequency associated with the second period according to a result of the measuring.