Method and device for detecting keystrokes

Abstract

A method and a device for detecting keystrokes belong to the technical field of electronic keystrokes. The method comprises the following steps: receiving original external signals and performing weighting addition to the signals to obtain effective external signals; detecting the effective external signals through frequency hopping and shielding the effective external signals out of the range from a first frequency to a second frequency; calculating the charge variation in a charge accumulation area corresponding to a keystroke after obtaining the external signals within the range from the first frequency to the second frequency through frequency conversion sampling, and identifying the external signals obtained through sampling as effective keystroke signals when the ratio of the chargevariation and the charge counterbalance is greater than the threshold value of charging varying ratio; and outputting a control signal when the frequency of obtaining effective keystroke signals through sampling in a first time window reaches or exceeds the predetermined frequency. The device comprises a signal receiving unit, a first postposition filter unit, a frequency hopping detecting unit, a frequency conversion sampling unit, a charge calculating unit and a signal output unit. By adopting the invention, the truth of signals and the detection accuracy of keystrokes can be improved.

Description

technical field [0001] The present invention relates to a method and device in the technical field of electronic keys, in particular to a key detection method and device. Background technique [0002] At present, various types of keys have been widely used in electronic products, among which capacitive touch keys are the most commonly used. The main principle of the capacitive touch button is that after the human body touches the button, it will change the charge on the button capacitor. Determine if a key touch action has occurred. The success rate of button detection directly affects the use of electronic products, and button detection usually refers to detecting the operation on a button to determine whether the button is pressed. [0003] The existing button detection method mainly includes the following basic steps: detect the button, and obtain the button signal; sample the button signal at a fixed frequency, and when the number of valid button signals sampled within...

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Problems solved by technology

[0004] In the above-mentioned button detection process, only discrete signals are considered, and the correlation with system signals is not considered, so the authenticity of the signal is very poor; if there is interference from external environmental factors, such as noise interference generated by mobile phones and other electrical appliances, etc., it will Increase the false trigger rate or missed detection rate of the key, thereby reducing the accuracy of key detection

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