Abstract: A capacitive sensor includes a first conductive structure; a second conductive structure that is counter to the first conductive structure, wherein the second conductive structure is movable relative to the first conductive structure in response to an external force acting thereon, wherein the second conductive structure is capacitively coupled to the first conductive structure to form a first capacitor having a first capacitance that changes with a change in a distance between the first conductive structure and second conductive structure; a signal generator configured to apply a first electrical signal step at an input or at an output of the first capacitor to induce a first voltage transient response at the output of first capacitor; and a diagnostic circuit configured to detect a fault in the capacitive sensor by measuring a first time constant of the first voltage transient response and detecting the fault based on the first time constant.

Abstract: A capacitive sensor includes a first electrode structure; a second electrode structure that is counter to the first electrode structure, wherein the second electrode structure is movable relative to the first electrode structure and is capacitively coupled to the first electrode structure to form a capacitor having a capacitance that changes with a change in a distance between the first electrode structure and second electrode structure; a signal generator configured to apply an electrical signal at an input or at an output of the capacitor to induce a voltage transient response at the output of capacitor; and a diagnostic circuit configured to detect a fault in the capacitive sensor by measuring a time constant of the first voltage transient response and detecting the fault based on the time constant and based on whether the first electrical signal is the pull-in signal or the non-pull-in signal.

Abstract: A method is provided for recording writing and audio from a writing session in a manner such that a depiction of the writing can be replayed in a synchronized fashion with the audio, the method comprising: recording movement of a writing element relative to a writing surface during a writing session using a writing capture device which produces writing data corresponding to positions of the writing element relative to the writing surface at sampled points in time; recording audio present during the writing session using an audio capture device to form audio data; associating time stamps with the writing and audio data; forming stroke vector data from the writing data by grouping the writing data into groups of temporally proximate writing data points based on the time stamps associated with the writing data, each group of temporally proximate writing data points defining a stroke vector that reflects a direction and magnitude of movement of the writing element relative to the writing surface over a period of