Dynamic mode switching for fast touch response

A touch sensor controller comprising:

• processing logic;
• a plurality of inputs configured to couple the processing logic with each of a plurality of sensor elements of a touch-sensing surface;
• and
• a capacitance sensor coupled with the plurality of inputs, wherein the capacitance sensor is configured to operate in a self capacitance mode to:
• perform a first scan to obtain a search measurement of a first set of the plurality of sensor elements of the touch-sensing surface to determine a presence of one or more conductive objects at the touch-sensing surface, wherein performing the search measurement comprises measuring one or more self capacitance values for the first set;
• repeat the performing the first scan until the one or more conductive objects are proximate to the touch-sensing surface;
• in response to determining the presence of the one or more conductive objects based on the first scan, performing a second scan to obtain a measurement of a second set of sensor elements of the touch-sensing surface, wherein performing the second scan comprises measuring self capacitance values for the second set;
• and,
• in response to the second scan, the capacitance sensor is configured to switch from operation in the self capacitance mode to operation in a mutual capacitance mode, and operate in the mutual capacitance mode to determine a location of the one or more conductive objects by performing a third scan to obtain a tracking measurement of a third set of sensor elements of the touch-sensing surface, wherein the tracking measurement comprises a measurement of a mutual capacitance between a pair of sensor elements of the third set of sensor elements, wherein the plurality of sensor elements comprise a plurality of row sensor elements and a plurality of column sensor elements, wherein the capacitance sensor is further configured determine the presence of the one or more conductive objects without regard to a location of the or more conductive objects on the touch-sensing surface by performing the first scan to obtain the search measurement of the first set of sensor elements and not all of the plurality of column sensor elements and the plurality of row sensor elements, wherein the first set comprises at least one of 1) only the plurality of column sensor elements, 2) only the plurality of row sensor elements, or 3) only a combination of alternating row sensor elements and alternating column sensor elements, wherein the second set comprises only the plurality of row sensor elements when the first set comprises 1), wherein the second set comprises only the plurality of column sensor elements when the first set comprises 2), wherein the second set comprise only a different combination of alternating row sensor elements and alternating column sensor elements when the first set comprises 3), and wherein the third set of sensor elements comprise at least one of the plurality of row sensor elements and at least one of the plurality of column sensor elements.

A touch-sensor controller comprising:

• a plurality of inputs configured to couple with each of a plurality of sensor elements of a touch-sensing surface;
• and
• a capacitance sensor coupled with the plurality of inputs, wherein the capacitance sensor is configured to measure self capacitance values for multiple sensor elements in a first set of the plurality of sensor elements to determine a presence of one or more conductive objects at the touch-sensing surface by performing a first scan to obtain a search measurement of the first set of sensor elements, repeat the performing the first scan until the one or more conductive objects are proximity to the touch-sensing surface, in response to determining the presence of the one or more conductive objects based on the first scan, the capacitance sensor is configured to perform a second scan to obtain a measurement of a second set of sensor elements of the touch-sensing surface, and in response to the second scan, the capacitance sensor is configured to switch from operation in a self capacitance mode to operation in a mutual capacitance mode to determine a location of the one or more conductive objects by performing a third scan to obtain a tracking measurement of at least a third set of the plurality of sensor elements, and wherein the third scan to obtain the tracking measurement comprises a mutual capacitance measurement of a mutual capacitance between at least one pair of the plurality of sensor elements, wherein the plurality of sensor elements comprise a plurality of row sensor elements and a plurality of column sensor elements, wherein the capacitance sensor is further configured determine the presence of the one or more conductive objects without regard to a location of the one or more conductive objects on the touch-sensing surface by performing the first scan to obtain the search measurement of the first set and not all of the plurality of column sensor elements and the plurality of row sensor elements, wherein the first set comprises at least one of 1) only the plurality of column sensor elements, 2) only the plurality of row sensor elements, or 3) only a combination of alternating row sensor elements and alternating column sensor elements, wherein the second set comprises only the plurality of row sensor elements when the first set comprises 1), wherein the second set comprises only the plurality of column sensor elements when the first set comprises 2), wherein the second set comprise only a different combination of alternating row sensor elements and alternating column sensor elements when the first set comprises 3), and wherein the third set of sensor elements comprise at least one of the plurality of row sensor elements and at least one of the plurality of column sensor elements.