Abstract: In one embodiment, a method includes conducting a first signal to a first source electrode external to a touch sensor. The first source electrode is capacitively coupled to the touch sensor through a touch object. The method further includes measuring a mutual capacitance between the first source electrode and the first measuring electrode. The method further includes identifying, based at least in part on the measured mutual capacitance and using a controller of the touch sensor, the touch object touching the touch sensor at a detected touch position.

Abstract: In an embodiment, a touch-sensitive device includes a controller, a shield sensor, a plurality of first electrodes, and a plurality of second electrodes. The plurality of first electrodes spans a first direction and the plurality of second electrodes spans a second direction that is different than the first direction. The controller electrically couples the plurality of first electrodes to the shield sensor. The shield sensor charges the plurality of first electrodes to cause substantially equal voltages to be present on the plurality of first electrodes and the plurality of second electrodes.

Abstract: An apparatus of one embodiment includes a sensor having a plurality of electrodes and a controller having a processor and a memory. The memory includes logic operable to configure the plurality of electrodes of the sensor to form a first cluster pattern including a first cluster and a second cluster. The first cluster and the second cluster each include two or more electrodes of the plurality of electrodes. The logic is further operable to determine a value associated with a capacitance of a first cluster and configure, in response to determining the value, the plurality of electrodes to form a second cluster pattern. The second cluster pattern includes a third cluster and a fourth cluster. The third cluster and the fourth cluster each include two or more electrodes of the plurality of electrodes and the third cluster is interleaved with the fourth cluster such that an electrode of the third cluster is positioned between two electrodes of the fourth cluster.

Abstract: In one embodiment, a device includes a controller, first electrodes, second electrodes, a plurality of sensors, and a shield sensor. The controller is operable to cause substantially equal voltages to be present on the first and second electrodes while measuring capacitances of the plurality of first electrodes electrically coupled to the shield sensor and measuring capacitances of the plurality of second electrodes electrically coupled to the plurality of sensors.

Abstract: An apparatus of one embodiment includes a sensor having a plurality of electrodes and a controller having a processor and a memory. The memory includes logic operable to configure the plurality of electrodes of the sensor to form a first cluster pattern including a first cluster and a second cluster. The first cluster and the second cluster each include two or more electrodes of the plurality of electrodes. The logic is further operable to determine a value associated with a capacitance of a first cluster and configure, in response to determining the value, the plurality of electrodes to form a second cluster pattern. The second cluster pattern includes a third cluster and a fourth cluster. The third cluster and the fourth cluster each include two or more electrodes of the plurality of electrodes and the third cluster is interleaved with the fourth cluster such that an electrode of the third cluster is positioned between two electrodes of the fourth cluster.

Abstract: An apparatus of one embodiment includes a sensor having a plurality of electrodes and a controller having a processor and a memory. The memory includes logic operable to configure the electrodes to form a first cluster pattern having a plurality of first clusters of two or more electrodes, apply voltage to each first cluster, and determine a plurality of first values associated with a capacitance of a first cluster. The logic is further operable to configure the electrodes to form a second cluster pattern having a plurality of second clusters of two or more electrodes, apply voltage to each second cluster, and determine a plurality of second values associated with a capacitance of a second cluster. At least one second cluster is interleaved with an adjacent second cluster. The logic is further operable to determine a position of an object based at least on the second values.

Abstract: In one embodiment, a touch-sensitive device includes a controller, horizontal electrodes, and vertical electrodes. The touch-sensitive device further includes a first plurality of switches that couple the horizontal electrodes to a first plurality of sensors, a second plurality of switches that couple the vertical electrodes to a second plurality of sensors, and a third and fourth plurality of switches that couple the horizontal and vertical electrodes to a shield sensor. The controller is operable to perform simultaneous hovering, touch, and proximity detection by selectively controlling, the first, second, third, and fourth plurality of switches. The hovering, touch, and proximity detection includes causing substantially equal voltages to be present on the horizontal and vertical electrodes while measuring capacitances using the shield sensor and either the first or second plurality of sensors.

Abstract: In one embodiment, a touch-sensitive device includes a controller, horizontal electrodes, and vertical electrodes. The touch-sensitive device further includes a first plurality of switches that couple the horizontal electrodes to a first plurality of sensors, a second plurality of switches that couple the vertical electrodes to a second plurality of sensors, and a third and fourth plurality of switches that couple the horizontal and vertical electrodes to a shield sensor. The controller is operable to perform simultaneous hovering, touch, and proximity detection by selectively controlling the first, second, third, and fourth plurality of switches. The hovering, touch, and proximity detection includes causing substantially equal voltages to be present on the horizontal and vertical electrodes while measuring capacitances using the shield sensor and either the first or second plurality of sensors.

Abstract: In one embodiment, a touch sensor includes a touch screen having a plurality of electrodes and a controller. The controller is operable to detect that an object is in proximity to the touch screen by measuring capacitance values from a reference area of the touch screen, determining a reference capacitance value using the measured capacitance values from the reference area, measuring capacitance values from a main area of the touch screen, and suppressing noise from the measured capacitance values of the main area by subtracting the reference capacitance value from the measured capacitance values of the main area of the touch screen. The reference area includes two or more of the plurality of electrodes, and at least one of the electrodes of the reference area is electrically coupled to a voltage reference. The main area includes electrodes of the plurality of electrodes that are not in the reference area.

Abstract: In one embodiment, a method includes modifying an amount of charge of a capacitance of a touch sensor. The modified amount of charge resulting in a voltage at the capacitance being a first pre-determined voltage level. The method also includes applying a first pre-determined amount of charge to the capacitance. The application of the first pre-determined amount of charge to the capacitance modifying the voltage at the capacitance from the first pre-determined voltage level to a first charging voltage level. The method also includes determining a first difference between the first charging voltage level and a reference voltage level; and determining whether a touch input to the touch sensor has occurred based on the first difference.

Abstract: In one embodiment, a method includes, by a base station, communicating a challenge to a transponder through a first communication link; and establishing a second communication link with the transponder. The second communication link is a capacitive link. The method also includes receiving a first response to the challenge through the first communication link with the transponder; sampling the second communication link to detect a signal corresponding to a second response to the challenge from the transponder; receiving the second response through the second communication link; and authorizing the transponder based on the first and second responses.

Abstract: In one embodiment, a method includes discharging a first capacitor and discharging a set of capacitances present on a first set of lines of a touch sensor. After discharging the first capacitor and the set of capacitances, the method further includes causing charge to be transferred to the set of capacitances during a first time period. After the first time period, the method includes causing charge to be transferred to the first capacitor and the set of capacitances during a second time period. After the second time period, the voltage across the first capacitor to a first threshold is compared. The method also includes determining whether a touch was detected by the touch sensor based on comparing the voltage across the first capacitor to the first threshold.

Abstract: In one embodiment, a method includes receiving one of a number of first voltages. Each of the first voltages results at least in part from a signal applied to an electrode of each of one or more nodes of a capacitive touch sensor. The method also includes receiving a second voltage across a measurement capacitor. The second voltage results at least in part on charging the measurement capacitor through application of a pre-determined voltage. The method also includes monitoring an output voltage during the charging of the measurement capacitor. The output voltage changes state based at least in part on a comparison of the second voltage relative to the one of the first voltages.

Abstract: In one embodiment, a method includes applying a first current to a capacitance of a touch sensor. The application of the first current to the capacitance for a first amount of time modifies the voltage at the capacitance from the reference voltage level to a first pre-determined voltage level. The method also includes applying a second current to an integration capacitor. The second current is proportional to the first current. The application of the second current to the integration capacitor for the first amount of time modifies the voltage at the integration capacitor from the reference voltage level to a first charging voltage level. The method also includes determining whether a touch input to the touch sensor has occurred based on the first charging voltage level.

Abstract: An apparatus of one embodiment includes a sensor having a plurality of electrodes and a controller having a processor and a memory. The memory includes logic operable to configure the electrodes to form a first cluster pattern having a plurality of first clusters of two or more electrodes, apply voltage to each first cluster, and determine a plurality of first values associated with a capacitance of a first cluster. The logic is further operable to configure the electrodes to form a second cluster pattern having a plurality of second clusters of two or more electrodes, apply voltage to each second cluster, and determine a plurality of second values associated with a capacitance of a second cluster. At least one second cluster is interleaved with an adjacent second cluster. The logic is further operable to determine a position of an object based at least on the second values.

Abstract: In one embodiment, a touch sensor includes a touch screen having a plurality of electrodes and a controller. The controller is operable to detect that an object is in proximity to the touch screen by measuring capacitance values from a reference area of the touch screen, determining a reference capacitance value using the measured capacitance values from the reference area, measuring capacitance values from a main area of the touch screen, and suppressing noise from the measured capacitance values of the main area by subtracting the reference capacitance value from the measured capacitance values of the main area of the touch screen. The reference area includes two or more of the plurality of electrodes, and at least one of the electrodes of the reference area is electrically coupled to a voltage reference. The main area includes electrodes of the plurality of electrodes that are not in the reference area.

Abstract: In one embodiment, a touch-sensitive device includes a controller, horizontal electrodes, and vertical electrodes. The touch-sensitive device further includes a first plurality of switches that couple the horizontal electrodes to a first plurality of sensors, a second plurality of switches that couple the vertical electrodes to a second plurality of sensors, and a third and fourth plurality of switches that couple the horizontal and vertical electrodes to a shield sensor. The controller is operable to perform simultaneous hovering, touch, and proximity detection by selectively controlling the first, second, third, and fourth plurality of switches. The hovering, touch, and proximity detection includes causing substantially equal voltages to be present on the horizontal and vertical electrodes while measuring capacitances using the shield sensor and either the first or second plurality of sensors.

Abstract: In one embodiment, a method includes applying a first current to a capacitance of a touch sensor. The application of the first current to the capacitance for a first amount of time modifies the voltage at the capacitance from the reference voltage level to a first pre-determined voltage level. The method also includes applying a second current to an integration capacitor. The second current is proportional to the first current. The application of the second current to the integration capacitor for the first amount of time modifies the voltage at the integration capacitor from the reference voltage level to a first charging voltage level. The method also includes determining whether a touch input to the touch sensor has occurred based on the first charging voltage level.

Abstract: In one embodiment, a method includes applying a first current to a capacitance of a touch sensor. The application of the first current to the capacitance for a first amount of time modifies the voltage at the capacitance from the reference voltage level to a first pre-determined voltage level. The method also includes applying a second current to an integration capacitor. The second current is proportional to the first current. The application of the second current to the integration capacitor for the first amount of time modifies the voltage at the integration capacitor from the reference voltage level to a first charging voltage level. The method also includes determining whether a touch input to the touch sensor has occurred based on the first charging voltage level.

Abstract: In one embodiment, a method includes applying a first current to a capacitance of a touch sensor. The application of the first current to the capacitance for a first amount of time modifies the voltage at the capacitance from the reference voltage level to a first pre-determined voltage level. The method also includes applying a second current to an integration capacitor. The second current is proportional to the first current. The application of the second current to the integration capacitor for the first amount of time modifies the voltage at the integration capacitor from the reference voltage level to a first charging voltage level. The method also includes determining whether a touch input to the touch sensor has occurred based on the first charging voltage level.