Abstract: Disclosed are sensing systems and methods that eliminate CPU intervention or interrupts when performing sensor scans of a touch interface, supports low power sensing operation without requiring periodic wake up of the CPU, and is scalable to multi-channel or multi-chip sensor configuration to support large touch screens or a high number of sensors. Sensor scanning is configured and controlled by an autonomous engine and comparison is completed by wake-up detection logic, operable without CPU interaction.

Abstract: Disclosed are sensing systems and methods that eliminate CPU intervention or interrupts when performing sensor scans of a touch interface, supports low power sensing operation without requiring periodic wake up of the CPU, and is scalable to multi-channel or multi-chip sensor configuration to support large touch screens or a high number of sensors. A sensor scanning module may operate in a chained-scan using direct memory access (CS-DMA) mode or an autonomous scan-multiple scan (AS-MS) mode to perform scanning of all sensors within a frame without requiring CPU intervention or generating CPU interrupts after every scan in the frame. The sensor scanning module may operate autonomously in a low-power always-on scan (LP-AOS) mode for multiple frames without CPU interaction until a touch event is detected. The CPU may operate in a low power sleep mode during the scan while providing consistent refresh rate and low touch-to-system wake up latency.

Abstract: A rotary encoder for capturing angular position of a target rotating over capacitive sensors. The rotary encoder includes a source plate. The rotary encoder includes a pair of capacitive sensors coupled to the source plate, and a target plate separated from the source plate by a gap. The target plate includes a spoke and a flange. The spoke is capacitively coupled to the pair of capacitive sensors and the flange is capacitively coupled to a ground pad. Each capacitive sensor of the pair of capacitive sensors is configured to detect a change in a capacitive value corresponding to an angular position of the spoke to the capacitive sensor. The target plate is mechanically coupled to a joystick. A movement of the joystick causes a rotation of the target plate about an axis to change the angular position of the spoke to the pair of capacitive sensors.

Abstract: Disclosed are sensing systems and methods that eliminate CPU intervention or interrupts when performing sensor scans of a touch interface, supports low power sensing operation without requiring periodic wake up of the CPU, and is scalable to multi-channel or multi-chip sensor configuration to support large touch screens or a high number of sensors. A sensor scanning module may operate in a chained-scan using direct memory access (CS-DMA) mode or an autonomous scan-multiple scan (AS-MS) mode to perform scanning of all sensors within a frame without requiring CPU intervention or generating CPU interrupts after every scan in the frame. The sensor scanning module may operate autonomously in a low-power always-on scan (LP-AOS) mode for multiple frames without CPU interaction until a touch event is detected. The CPU may operate in a low power sleep mode during the scan while providing consistent refresh rate and low touch-to-system wake up latency.

Abstract: Disclosed are sensing systems and methods that eliminate CPU intervention or interrupts when performing sensor scans of a touch interface, supports low power sensing operation without requiring periodic wake up of the CPU, and is scalable to multi-channel or multi-chip sensor configuration to support large touch screens or a high number of sensors. A sensor scanning module may operate in a chained-scan using direct memory access (CS-DMA) mode or an autonomous scan-multiple scan (AS-MS) mode to perform scanning of all sensors within a frame without requiring CPU intervention or generating CPU interrupts after every scan in the frame. The sensor scanning module may operate autonomously in a low-power always-on scan (LP-AOS) mode for multiple frames without CPU interaction until a touch event is detected. The CPU may operate in a low power sleep mode during the scan while providing consistent refresh rate and low touch-to-system wake up latency.

Abstract: Information associated with a plurality of components of a capacitance sensing system is received. Performance of the capacitance sensing system is simulated based on the information associated with the plurality of components of the capacitance sensing system. A set of configuration parameters for a capacitance sensing controller is generated without user intervention based on the simulated performance of the capacitance sensing system.

Abstract: Apparatuses and methods of distinguishing between a finger and stylus proximate to a touch surface are described. One apparatus includes a first circuit to obtain capacitance measurements of sense elements when a conductive object is proximate to a touch surface. The apparatus also includes a second circuit coupled to the first circuit. The second circuit is operable to detect whether the conductive object activates the first sense element, second sense element, or both, in view of the capacitance measurements. To distinguish between a stylus and a finger as the conductive object, the second circuit determines the conductive object as being the stylus when the second sense element is activated and the first sense element is not activated and determines the conductive object as being the finger when the first sense element and the second sense element are activated.

Abstract: Apparatuses and methods of distinguishing between a finger and stylus proximate to a touch surface are described. One apparatus includes a first circuit to obtain capacitance measurements of sense elements when a conductive object is proximate to a touch surface. The apparatus also includes a second circuit coupled to the first circuit. The second circuit is operable to detect whether the conductive object activates the first sense element, second sense element, or both, in view of the capacitance measurements. To distinguish between a stylus and a finger as the conductive object, the second circuit determines the conductive object as being the stylus when the second sense element is activated and the first sense element is not activated and determines the conductive object as being the finger when the first sense element and the second sense element are activated.

Abstract: Apparatuses and methods of distinguishing between a finger and stylus proximate to a touch surface are described. One apparatus includes a first circuit to obtain capacitance measurements of sense elements when a conductive object is proximate to a touch surface. The apparatus also includes a second circuit coupled to the first circuit. The second circuit is operable to detect whether the conductive object activates the first sense element, second sense element, or both, in view of the capacitance measurements. To distinguish between a stylus and a finger as the conductive object, the second circuit determines the conductive object as being the stylus when the second sense element is activated and the first sense element is not activated and determines the conductive object as being the finger when the first sense element and the second sense element are activated.

Abstract: A circuit, system, and method for converting mutual capacitance to a digital value is described. Charge packets are transferred from a mutual capacitance to a pair of integration capacitors during alternate charge and discharge cycles. The time required to bring the discharged integration capacitor to the same potential as the charged integration capacitor with a current source is measured as a single-slope analog-to-digital converter (ADC). The output of the ADC is representative of the mutual capacitance.

Abstract: Apparatuses and methods of distinguishing between a finger and stylus proximate to a touch surface are described. One apparatus includes a first circuit to obtain capacitance measurements of sense elements when a conductive object is proximate to a touch surface. The apparatus also includes a second circuit coupled to the first circuit. The second circuit is operable to detect whether the conductive object activates the first sense element, second sense element, or both, in view of the capacitance measurements. To distinguish between a stylus and a finger as the conductive object, the second circuit determines the conductive object as being the stylus when the second sense element is activated and the first sense element is not activated and determines the conductive object as being the finger when the first sense element and the second sense element are activated.

Abstract: Apparatuses and methods of distinguishing between a finger and stylus proximate to a touch surface are described. One apparatus includes a first circuit to obtain capacitance measurements of sense elements when a conductive object is proximate to a touch surface. The apparatus also includes a second circuit coupled to the first circuit. The second circuit is operable to detect whether the conductive object activates the first sense element, second sense element, or both, in view of the capacitance measurements. To distinguish between a stylus and a finger as the conductive object, the second circuit determines the conductive object as being the stylus when the second sense element is activated and the first sense element is not activated and determines the conductive object as being the finger when the first sense element and the second sense element are activated.

Abstract: Apparatuses and methods of distinguishing between a finger and a stylus proximate to a touch surface are described. One apparatus includes a first circuit to obtain capacitance measurements of sense elements when a conductive object is proximate to a touch surface. The apparatus also includes a second circuit coupled to the first circuit. The second circuit is operable to detect whether the conductive object activates the first sense element, second sense element, or both, in view of the capacitance measurements. To distinguish between a stylus and a finger as the conductive object, the second circuit determines the conductive object as being the stylus when the second sense element is activated and the first sense element is not activated and determines the conductive object as being the finger when the first sense element and the second sense element are activated.

Abstract: A circuit, system, and method for converting mutual capacitance to a digital value is described. Charge packets are transferred from a mutual capacitance to a pair of integration capacitors during alternate charge and discharge cycles. The time required to bring the discharged integration capacitor to the same potential as the charged integration capacitor with a current source is measured as a single-slope analog-to-digital converter (ADC). The output of the ADC is representative of the mutual capacitance.

Abstract: Disclosed herein are systems, methods, and devices for touch event and hover event detection. Devices as disclosed herein may include a first electrode implemented in a capacitive sensor. The devices may also include a second electrode implemented in the capacitive sensor. The devices may further include a controller coupled to the first electrode and the second electrode, where the controller is configured to determine whether a touch event or a hover event has occurred based on a first self-capacitance measurement of the first electrode, a second self-capacitance measurement of the second electrode, and a mutual capacitance measurement of the first electrode and the second electrode.

Abstract: Apparatuses and methods of capacitive buttons and detecting and differentiating touches from different size conductive objects on the capacitive buttons. One apparatus includes a capacitance-sensing circuit coupled to a capacitive button. The capacitive button includes a first sense element and a second sense element. The capacitance-sensing circuit is operative to measure signals from the first sense element and the second sense element with a sensing parameter (also referred to as tuning properties) set to a first value. The signals correspond to capacitances of the first sense element and second sense element. An inner perimeter of the first sense element is disposed to surround (at least in part) an outer perimeter of the second sense element. The apparatus further includes processing logic coupled to the capacitance-sensing circuit.

Abstract: An apparatus includes multiple capacitive sensing elements coupled through a filter network. The apparatus can include a control device configured to excite the capacitive sensing elements with different scanning frequencies and determine capacitances corresponding to each of the capacitive sensing elements based on sensor responses to the excitation of the capacitive sensing elements with the different scanning frequencies and a configuration of the filter network.