Abstract: An apparatus includes a moveable electrode which moves along an interstitial pathway defined by four fixed electrodes. The first and second fixed electrodes are separated by a first distance. The third and fourth fixed electrodes are separated by a second distance and adjacent to the first and second fixed electrodes, respectively. A capacitance sensing circuit coupled to the four fixed electrodes determines a first capacitance using the first and second fixed electrodes and a second capacitance using the third and fourth fixed electrodes. In some examples, the apparatus also comprises fifth and sixth fixed electrodes separated by a third distance and orthogonal to the first and second fixed electrodes and seventh and eighth fixed electrodes separated by a fourth distance and orthogonal to the third and fourth fixed electrodes. The fifth and seventh fixed electrodes are adjacent, and the sixth and eighth fixed electrodes are adjacent.

Abstract: A system includes a housing, a sensing electrode disposed within the housing, and a connecting electrode. The system also includes a capacitive sensing circuit galvanically connected to the connecting electrode at a first port, but not to the sensing electrode. The capacitive sensing circuit is configured to determine a first capacitance between the first port and a ground. The first capacitance includes a variable capacitance between the connecting electrode and a person when the person is touching the housing.

Abstract: An apparatus includes a first electrode, a second electrode, and a third electrode having first and second opposing surfaces. The first opposing surface is adjacent the first electrode and separated from the first electrode by a first distance, and the second opposing surface is adjacent the second electrode and separated from the second electrode by a second distance. The third electrode is configured to move relative to the first and second electrodes. A capacitance sensing circuit is coupled to the first and second electrodes. The capacitive sensing circuit is configured to determine a capacitance using the first and second electrodes.

Abstract: Described example user interface control apparatus includes a first structure, with a first side, conductive capacitor plate structures spaced along a first direction on the first side, a movable second structure with an auxiliary conductive structure, and an interface circuit to provide excitation signals to, and receive sense signals from, the conductive capacitor plate structures to perform a mutual capacitance test and a self-capacitance test of individual ones of the conductive capacitor plate structures to determine a position of the second structure or a user's finger relative to the first structure along the first direction.

Abstract: A device includes an electrical circuit and a mutual-capacitance sensing circuit coupled to the electrical circuit. The mutual-capacitance sensing circuit includes mutual-capacitance sensing electrodes including a transmitter electrode and receiver electrode. The device also includes a conductive overlay over the mutual-capacitance sensing electrodes. The mutual-capacitance sensing circuit is configured to detect deflection of a portion of the conductive overlay relative to the mutual-capacitance sensing electrodes. The receiver electrode has a shape with an inner edge, and the transmitter electrode has a shape with an outer edge that is at least partially surrounded by the inner edge of the receiver electrode.

Abstract: An apparatus includes a first oscillator circuit coupled to a first electrode and a second oscillator circuit coupled to a second electrode. The first and second oscillator circuits oscillate synchronously in response to a capacitance between the first and second electrodes being greater than or equal to a threshold coupling capacitance and asynchronously in response to the capacitance being less than the threshold coupling capacitance. The first and second electrodes are separated by a distance, such that a disturbance within the distance increases the capacitance between the electrodes equal to or above the threshold coupling capacitance. The frequency of the first oscillator circuit is inversely proportional to a capacitance of the first electrode, and the frequency of the second oscillator circuit is inversely proportional to a capacitance of the second electrode.

Abstract: A device includes an electrical circuit and a mutual-capacitance sensing circuit coupled to the electrical circuit. The mutual-capacitance sensing circuit includes mutual-capacitance sensing electrodes including a transmitter electrode and receiver electrode. The device also includes a conductive overlay over the mutual-capacitance sensing electrodes. The mutual-capacitance sensing circuit is configured to detect deflection of a portion of the conductive overlay relative to the mutual-capacitance sensing electrodes. The receiver electrode has a shape with an inner edge, and the transmitter electrode has a shape with an outer edge that is at least partially surrounded by the inner edge of the receiver electrode.

Abstract: Described example user interface control apparatus includes a first structure, with a first side, conductive capacitor plate structures spaced along a first direction on the first side, a movable second structure with an auxiliary conductive structure, and an interface circuit to provide excitation signals to, and receive sense signals from, the conductive capacitor plate structures to perform a mutual capacitance test and a self-capacitance test of individual ones of the conductive capacitor plate structures to determine a position of the second structure or a user's finger relative to the first structure along the first direction.

Abstract: Described example user interface control apparatus includes a first structure, with a first side, conductive capacitor plate structures spaced along a first direction on the first side, a movable second structure with an auxiliary conductive structure, and an interface circuit to provide excitation signals to, and receive sense signals from, the conductive capacitor plate structures to perform a mutual capacitance test and a self-capacitance test of individual ones of the conductive capacitor plate structures to determine a position of the second structure or a user's finger relative to the first structure along the first direction.

Abstract: A device includes an electrical circuit and a mutual-capacitance sensing circuit coupled to the electrical circuit. The mutual-capacitance sensing circuit includes mutual-capacitance sensing electrodes including a transmitter electrode and receiver electrode. The device also includes a conductive overlay over the mutual-capacitance sensing electrodes. The mutual-capacitance sensing circuit is configured to detect deflection of a portion of the conductive overlay relative to the mutual-capacitance sensing electrodes. The receiver electrode has a shape with an inner edge, and the transmitter electrode has a shape with an outer edge that is at least partially surrounded by the inner edge of the receiver electrode.

Abstract: An apparatus includes a first oscillator circuit coupled to a first electrode and a second oscillator circuit coupled to a second electrode. The first and second oscillator circuits oscillate synchronously in response to a capacitance between the first and second electrodes being greater than or equal to a threshold coupling capacitance and asynchronously in response to the capacitance being less than the threshold coupling capacitance. The first and second electrodes are separated by a distance, such that a disturbance within the distance increases the capacitance between the electrodes equal to or above the threshold coupling capacitance. The frequency of the first oscillator circuit is inversely proportional to a capacitance of the first electrode, and the frequency of the second oscillator circuit is inversely proportional to a capacitance of the second electrode.

Abstract: Disclosed examples include optical and capacitive position detection systems and user interface control apparatus to detect relative positions of a stationary first structure and a movable second structure. The optical system includes pairs of optical source and sensor devices spaced along a first direction on the first structure and a reflector extending along the first direction on the second structure to selectively reflect light from one of the optical sources to the corresponding optical sensor of a given pair when the reflector is proximate the given pair. The capacitive sensing system includes capacitor plate structures on the first structure and a conductive structure on the second structure to move along the first direction to selectively modify a capacitance of a given group of two or more of the plate structures.

Abstract: An apparatus includes a moveable electrode which moves along an interstitial pathway defined by four fixed electrodes. The first and second fixed electrodes are separated by a first distance. The third and fourth fixed electrodes are separated by a second distance and adjacent to the first and second fixed electrodes, respectively. A capacitance sensing circuit coupled to the four fixed electrodes determines a first capacitance using the first and second fixed electrodes and a second capacitance using the third and fourth fixed electrodes. In some examples, the apparatus also comprises fifth and sixth fixed electrodes separated by a third distance and orthogonal to the first and second fixed electrodes and seventh and eighth fixed electrodes separated by a fourth distance and orthogonal to the third and fourth fixed electrodes. The fifth and seventh fixed electrodes are adjacent, and the sixth and eighth fixed electrodes are adjacent.

Abstract: An apparatus includes a first electrode, a second electrode, and a third electrode having first and second opposing surfaces. The first opposing surface is adjacent the first electrode and separated from the first electrode by a first distance, and the second opposing surface is adjacent the second electrode and separated from the second electrode by a second distance. The third electrode is configured to move relative to the first and second electrodes. A capacitance sensing circuit is coupled to the first and second electrodes. The capacitive sensing circuit is configured to determine a capacitance using the first and second electrodes.

Abstract: A system includes a housing, a sensing electrode disposed within the housing, and a connecting electrode. The system also includes a capacitive sensing circuit galvanically connected to the connecting electrode at a first port, but not to the sensing electrode. The capacitive sensing circuit is configured to determine a first capacitance between the first port and a ground. The first capacitance includes a variable capacitance between the connecting electrode and a person when the person is touching the housing.

Abstract: Disclosed examples include optical and capacitive position detection systems and user interface control apparatus to detect relative positions of a stationary first structure and a movable second structure. The optical system includes pairs of optical source and sensor devices spaced along a first direction on the first structure and a reflector extending along the first direction on the second structure to selectively reflect light from one of the optical sources to the corresponding optical sensor of a given pair when the reflector is proximate the given pair. The capacitive sensing system includes capacitor plate structures on the first structure and a conductive structure on the second structure to move along the first direction to selectively modify a capacitance of a given group of two or more of the plate structures.

Abstract: Disclosed examples include optical and capacitive position detection systems and user interface control apparatus to detect relative positions of a stationary first structure and a movable second structure. The optical system includes pairs of optical source and sensor devices spaced along a first direction on the first structure and a reflector extending along the first direction on the second structure to selectively reflect light from one of the optical sources to the corresponding optical sensor of a given pair when the reflector is proximate the given pair. The capacitive sensing system includes capacitor plate structures on the first structure and a conductive structure on the second structure to move along the first direction to selectively modify a capacitance of a given group of two or more of the plate structures.

Abstract: Described example user interface control apparatus includes a first structure, with a first side, conductive capacitor plate structures spaced along a first direction on the first side, a movable second structure with an auxiliary conductive structure, and an interface circuit to provide excitation signals to, and receive sense signals from, the conductive capacitor plate structures to perform a mutual capacitance test and a self-capacitance test of individual ones of the conductive capacitor plate structures to determine a position of the second structure or a user's finger relative to the first structure along the first direction.

Abstract: Described example user interface control apparatus includes a first structure, with a first side, conductive capacitor plate structures spaced along a first direction on the first side, a movable second structure with an auxiliary conductive structure, and an interface circuit to provide excitation signals to, and receive sense signals from, the conductive capacitor plate structures to perform a mutual capacitance test and a self-capacitance test of individual ones of the conductive capacitor plate structures to determine a position of the second structure or a user's finger relative to the first structure along the first direction.

Abstract: An apparatus includes a plurality of capacitive sensors arranged in a matrix on a substrate. A measuring circuitry measures the capacitance of each of a plurality of row lines and a plurality of column lines in the matrix coupled to the capacitive sensors. A first electrode is on the substrate on a first edge of the matrix and is proximal to a first corner of the matrix. The first electrode is coupled to the measuring circuitry. A second electrode is on the substrate on the first edge of the matrix and is proximal to a second corner of the matrix, the second corner opposing the first corner on the first edge. The second electrode is coupled to the measuring circuitry. The measuring circuitry determines the positions of two touches to the touch pad. Methods are disclosed.