Detecting interference in an input device having electrodes

摘要

A method for detecting interference in an input device, the method involving: driving a transmitter signal onto a transmitter sensor electrode of the input device; receiving a resulting signal from a receiver sensor electrode of the input device; sampling a first value associated with the resulting signal during a first half of a sensing cycle; sampling a second value associated with the resulting signal during a second half of the sensing cycle; generating an interference value based on the first value and the second value; determining, based on the first value and the second value, an input in a sensing region of the input device; and comparing the interference value to a noise threshold.

主权项

1. A method for detecting interference in an input device, the method comprising:
driving a transmitter signal onto a transmitter sensor electrode of the input device; receiving a resulting signal from a receiver sensor electrode of the input device; resetting accumulator circuitry associated with an amplifier at a start of a first half of a sensing cycle; sampling a first value associated with the resulting signal during the first half of the sensing cycle, wherein the accumulator circuitry accumulates the first value during the first half of the sensing cycle; resetting the accumulator circuitry at a start of a second half of the sensing cycle; sampling a second value associated with the resulting signal during the second half of the sensing cycle, wherein the accumulator circuitry accumulates the second value during the second half of the sensing cycle, and wherein the first value and the second value are each a different single voltage level; generating an interference value based on the first value and the second value; determining, based on the first value and the second value, an input in a sensing region of the input device; comparing the interference value to a noise threshold; generating a comparison between a rail voltage range of the amplifier and at least one selected from a group consisting of the first value and the second value; and issuing a first flag in response to the comparison.