Abstract: A method including applying a first excitation voltage to an electrode of a touch sensor which charges a capacitive node associated with the electrode from a first voltage level to a second voltage level that is greater than the first voltage level. A first measurement measures a charge to change from the first voltage level to the second voltage level. A second excitation voltage is applied to the electrode which charges the capacitive node from the second voltage level to a third voltage level that is greater than the second voltage level. The capacitive node is discharged from the third voltage level to a fourth voltage level that is less than the second voltage level. A second measurement measures a charge to change from the third voltage level to the fourth voltage level. A measured charge signal is generated based on the first measurement and the second measurement.

Abstract: A multi-channel capacitive sensor for measuring the capacitances of a plurality of sense electrodes to a system reference potential. The sensor comprises a sample capacitor having a first terminal and a second terminal, a first diode having a first terminal coupled to the second terminal of the sample capacitor and a second terminal coupled to a first sense electrode, and a second diode having a first terminal coupled to the second terminal of the sample capacitor and a second terminal coupled to a second sense electrode. The sample capacitor and diodes are coupled to a control circuit, e.g. implemented in a microcontroller. The control circuit is operable to apply a drive signal, e.g. a series of voltage pulses, to the first terminal of the sample capacitor while simultaneously applying a bias signal to the second terminal of one or other of the diodes to prevent the diode from conducting the drive signal.

Abstract: A method including applying a first excitation voltage to an electrode of a touch sensor which charges a capacitive node associated with the electrode from a first voltage level to a second voltage level that is greater than the first voltage level. A first measurement measures a charge to change from the first voltage level to the second voltage level. A second excitation voltage is applied to the electrode which charges the capacitive node from the second voltage level to a third voltage level that is greater than the second voltage level. The capacitive node is discharged from the third voltage level to a fourth voltage level that is less than the second voltage level. A second measurement measures a charge to change from the third voltage level to the fourth voltage level. A measured charge signal is generated based on the first measurement and the second measurement.

Abstract: A method including applying a first excitation voltage to an electrode of a touch sensor which charges a capacitive node associated with the electrode from a first voltage level to a second voltage level that is greater than the first voltage level. A first measurement measures a charge to change from the first voltage level to the second voltage level. A second excitation voltage is applied to the electrode which charges the capacitive node from the second voltage level to a third voltage level that is greater than the second voltage level. The capacitive node is discharged from the third voltage level to a fourth voltage level that is less than the second voltage level. A second measurement measures a charge to change from the third voltage level to the fourth voltage level. A measured charge signal is generated based on the first measurement and the second measurement.

Abstract: A multi-channel capacitive sensor for measuring the capacitances of a plurality of sense electrodes to a system reference potential. The sensor comprises a sample capacitor having a first terminal and a second terminal, a first diode having a first terminal coupled to the second terminal of the sample capacitor and a second terminal coupled to a first sense electrode, and a second diode having a first terminal coupled to the second terminal of the sample capacitor and a second terminal coupled to a second sense electrode. The sample capacitor and diodes are coupled to a control circuit, e.g. implemented in a microcontroller. The control circuit is operable to apply a drive signal, e.g. a series of voltage pulses, to the first terminal of the sample capacitor while simultaneously applying a bias signal to the second terminal of one or other of the diodes to prevent the diode from conducting the drive signal.

Abstract: In one embodiment, a device includes a multi-channel capacitive sensor and a control circuit. The control circuit is configured to ground a first sense capacitor and a second sense capacitor of the multi-channel capacitive sensor. The first sense capacitor and the second sense capacitor are adapted to be connected to a drive line. The control circuit is configured to charge, by a first voltage provided on a pin of the controller, an in-series combination of a sample capacitor and the first sense capacitor while not charging the second sense capacitor by the first voltage provided on the pin of the controller. The control circuit is further configured to measure a second voltage on the pin of the controller resulting at least in part from charging the in-series combination, the second voltage providing an indication of a capacitance of the first sense capacitor.

Abstract: Disclosed is a touch position sensor. Force detection circuitry can be included with the position sensor, for example, to determine an amount of force applied to a touch panel of the sensor.

Abstract: Disclosed is a touch position sensor. Force detection circuitry can be included with the position sensor, for example, to determine an amount of force applied to a touch panel of the sensor.

Abstract: Disclosed is a touch position sensor. Force detection circuitry can be included with the position sensor, for example, to determine an amount of force applied to a touch panel of the sensor.

Abstract: In one embodiment, a sensor includes a voltage driver operable to provide an alternating voltage and an integrator circuit. The sensor further includes a first variable resistance element coupled to a first output of the voltage driver and an input of the integrator circuit. The integrator circuit is operable to measure a parameter of the first variable resistance element over a period of time. The sensor further includes circuitry operable to determine, based on the measured parameter, an amount of force applied to a touch sensing panel.

Abstract: A method including applying a first excitation voltage to an electrode of a touch sensor which charges a capacitive node associated with the electrode from a first voltage level to a second voltage level that is greater than the first voltage level. A first measurement measures a charge to change from the first voltage level to the second voltage level. A second excitation voltage is applied to the electrode which charges the capacitive node from the second voltage level to a third voltage level that is greater than the second voltage level. The capacitive node is discharged from the third voltage level to a fourth voltage level that is less than the second voltage level. A second measurement measures a charge to change from the third voltage level to the fourth voltage level. A measured charge signal is generated based on the first measurement and the second measurement.

Abstract: In one embodiment, a device includes a multi-channel capacitive sensor and a control circuit. The control circuit is configured to ground a first sense capacitor and a second sense capacitor of the multi-channel capacitive sensor. The first sense capacitor and the second sense capacitor are adapted to be connected to a drive line. The control circuit is configured to charge, by a first voltage provided on a pin of the controller, an in-series combination of a sample capacitor and the first sense capacitor while not charging the second sense capacitor by the first voltage provided on the pin of the controller. The control circuit is further configured to measure a second voltage on the pin of the controller resulting at least in part from charging the in-series combination, the second voltage providing an indication of a capacitance of the first sense capacitor.

Abstract: A multi-channel capacitive sensor comprises a sample capacitor having first and second terminals, a first diode having a first terminal coupled to the second terminal of the sample capacitor and a second terminal coupled to a first sense electrode, and a second diode having a first terminal coupled to the second terminal of the sample capacitor and a second terminal coupled to a second sense electrode. The sample capacitor and diodes are coupled to a control circuit. The control circuit is operable to apply a drive signal to the first terminal of the sample capacitor while simultaneously applying a bias signal to the second terminal of one or other of the diodes to prevent the diode from conducting the drive signal.

Abstract: Disclosed is a touch position sensor. Force detection circuitry can be included with the position sensor, for example, to determine an amount of force applied to a touch panel of the sensor.

Abstract: In certain embodiments, an apparatus includes a touch sensor that includes a touch-sensitive area and a touch-sensor controller. The touch-sensor controller is operable to: scan two or more electrodes within the touch-sensitive area to determine a first location associated with an object within the touch-sensitive area, predict, based on the first location and one or more metrics, two or more next locations associated with the object, select, based on a first next location of the two or more next locations, a first region within the touch-sensitive area, select, based on a second next location of the two or more next locations, a second region within the touch-sensitive area, and scan two or more electrodes within the first region and two or more electrodes within the second region to determine a second location associated with the object. The second region is at least partially different from the first region.

Abstract: In one embodiment, a method includes receiving sensor data from one or more sensors in or on a stylus, the stylus including one or more electrodes and one or more computer-readable non-transitory storage media embodying logic for wirelessly transmitting signals to a device through a touch sensor of the device. The method includes generating a carrier signal and modulating the carrier signal to communicate the sensor data and wirelessly transmitting from the stylus to the device the carrier signal as modulated through the touch sensor of the device.

Abstract: In one embodiment, a method comprises detecting, by a hardware accelerator, that a value has been written to a first location of a memory, the first location identified by a first address. The method further includes adding the value to an accumulated value stored in an accumulator register of the hardware accelerator and storing the result in the accumulator register. The method further includes comparing the value to a maximum value stored in a first register of the hardware accelerator and overwriting the maximum value with the value if the value is greater than the maximum value. The method also includes comparing the value to a minimum value stored in a second register of the hardware accelerator and overwriting the minimum value with the value if the value is less than the minimum value.

Abstract: In one embodiment, a method includes receiving sensor data from one or more sensors in or on a stylus, the stylus including one or more electrodes and one or more computer-readable non-transitory storage media embodying logic for wirelessly transmitting signals to a device through a touch sensor of the device. The method includes generating a carrier signal and modulating the carrier signal to communicate the sensor data and wirelessly transmitting from the stylus to the device the carrier signal as modulated through the touch sensor of the device.

Abstract: In one embodiment, a method includes receiving sensor data from one or more sensors in or on a stylus, the stylus including one or more electrodes and one or more computer-readable non-transitory storage media embodying logic for wirelessly transmitting signals to a device through a touch sensor of the device. The method includes generating a carrier signal and modulating the carrier signal to communicate the sensor data and wirelessly transmitting from the stylus to the device the carrier signal as modulated through the touch sensor of the device.

Abstract: In certain embodiments, an apparatus includes a touch sensor that includes a touch-sensitive area and a touch-sensor controller. The touch-sensor controller is operable to: select a first region around a determined first location associated with an object within the touch-sensitive area, select a second region around the determined first location associated with the object within the touch-sensitive area, and scan two or more electrodes within the first region and two or more electrodes within the second region to determine a second location associated with the object within the touch-sensitive area.