Active pen for matrix sensor

A processing system configured to drive a capacitive sensing device, the capacitive sensing device having a plurality of sensor electrodes organized into a plurality of sets, the processing system comprising:

• a sensor module configured to drive the plurality of sensor electrodes with modulated signals having a first frequency, the sensor module comprising:
• a first plurality of receivers coupled to the plurality of sensor electrodes, wherein the first plurality of receivers are configured to obtain first resulting signals comprising effects corresponding to the modulated signals, and
• a second plurality of receivers, wherein each receiver of the second plurality of receivers is coupled to an associated set of the plurality of sensor electrodes and configured to obtain second resulting signals comprising effects corresponding to active signals having a second frequency, wherein the first plurality of receivers and the second plurality of receivers are disjoint sets of receivers;
• wherein the sensor module is further configured to demodulate the first resulting signals based on the first frequency of the modulated signals and demodulate the second resulting signals based on the second frequency, wherein the second frequency is different than the first frequency, and
• wherein the sensor module is configured to determine first positional information for a first input object based on the demodulation of the first resulting signals and second positional information for a second input object based on the demodulation of the second resulting signals.

A method for detecting presence of an input object using a capacitive sensing device, the capacitive sensing device having a plurality of sensor electrodes organized in a plurality of sots, the method comprising:

• driving the plurality of sensor electrodes with modulated signals having a first frequency;
• receiving first resulting signals at a first plurality of receivers comprising effects corresponding to the modulated signals;
• receiving second resulting signals at a second plurality of receivers comprising effects corresponding to active signals having a second frequency, wherein the first plurality of receivers and the second plurality of receivers are disjoint sets of receivers;
• and
• demodulating the first resulting signals based on the first frequency of the modulated signals and the second resulting signals based on the second frequency, wherein the second frequency is different than the first frequency;
• and
• determining first positional information for a first input object based on the demodulation of the first resulting signals and second positional information for a second input object based on the demodulation of the second resulting signals.