Self-adaptive judging method for capacitor type push-button

Abstract

The invention is a self-adapting judging method for capacitance keys, able to judge whether the capacitance keys enter or exit keying state, and comprising the steps of: filtering the detected signal; based on initialization values, obtaining key-free reference baselines in initial state; based on experience values, obtaining noise baselines and key baselines in initial state; by comparing the noise and keying baselines with the filtered detected signal, judging whether the keys enter or exit the keying state; self-adaptively regulating the key-free reference baselines, noise baselines and key baselines.

Description

Technical field [0001] The invention relates to capacitance detection, in particular to a capacitance judgment method for touch key technology. Background technique [0002] Capacitive touch button technology has been developed for many years, but due to cost and stability reasons, it has only become popular in electronic devices in recent years, especially in some mobile phones and home appliances, which are durable and reasonably priced. Its advantages are more obvious, and its fully sealed and planar appearance has brought a brand new revolution to industrial design. [0003] The core of all capacitive touch sensing systems is a set of conductors that interact with electric fields. Under the skin, human tissues are filled with conductive electrolytes (a lossy dielectric). It is this conductive property of the finger that makes capacitive touch sensing possible. [0004] In capacitance measurement, capacitance signals are often converted into digital signals for further process...

AI Technical Summary

Problems solved by technology

[0006] 1. Capacitive buttons may be used in various environments. When the ambient humidity and temperature change, the readings caused by the unit capacitance value will vary. At this time, it will be difficult to use one sensitivity to adapt to all environments;

[0007] 2. In actual use, the thickness and capacitance parameters of the panel are different. In the prior art, the method of adjusting the peripheral circuit is used to set the sensitivity and reference value of the button, which brings difficulty to the design and uncertainty of production. The circuit reuse poor rate;

[0008] 3. In the actual use environment, there will be a lot of noise, which requires that the key judgment cannot be very sensitive; and the application environment may require higher sensitivity, and the contradiction between the two may easily lead to wrong judgment results

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