CN114337634A - Capacitive touch key detection circuit and detection method thereof - Google Patents
Capacitive touch key detection circuit and detection method thereof Download PDFInfo
- Publication number
- CN114337634A CN114337634A CN202111647909.2A CN202111647909A CN114337634A CN 114337634 A CN114337634 A CN 114337634A CN 202111647909 A CN202111647909 A CN 202111647909A CN 114337634 A CN114337634 A CN 114337634A
- Authority
- CN
- China
- Prior art keywords
- touch key
- resistor
- capacitive touch
- discharge unit
- detection circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Electronic Switches (AREA)
Abstract
The invention discloses a capacitive touch key detection circuit and a detection method thereof, wherein the circuit comprises: the first order charge and discharge unit, the second order charge and discharge unit, the filter unit and the button electric capacity that constitutes by the spring button, the button electric capacity is connected between first order charge and discharge unit and second order charge and discharge unit, and the signal of input passes through first order charge and discharge unit is right the button electric capacity carries out the charge and discharge, carries out oscillation signal after the first order charge and discharge unit handles passes through second order charge and discharge unit carries out the charge and discharge, the process again forms stable voltage signal after the filter unit filters. The invention processes the input oscillation signal through the constructed capacitive touch key detection circuit and then outputs a stable voltage signal, and identifies the current state of the touch key through the amplitude of the voltage signal, thereby not only having high detection precision, but also having adjustable oscillation frequency and being programmable and being suitable for various different occasions.
Description
Technical Field
The invention relates to key detection, in particular to a capacitive touch key detection circuit and a detection method thereof.
Background
The touch key detection schemes on the market at present are mainly divided into two categories, one is a capacitive touch key detection chip with high integration level, and the capacitive touch key detection chip has the advantages of small volume, high integration level, accurate detection and the like, and has the defects of inflexible application occasions, incapability of randomly matching the number of keys and higher application cost; the other is a discrete detection scheme which can be divided into a resistance-type detection scheme and a capacitance-type detection scheme, while the capacitance-type detection scheme is mostly used in the market, the detection scheme is a detection circuit formed by combining discrete devices such as an oscillator, a capacitor, a resistor, a comparator, a single chip microcomputer and the like, but the detection circuit is not suitable for application occasions with higher space requirements due to more devices and larger volume, and has fixed oscillation frequency and low detection precision, so that the detection circuit is difficult to be uniformly suitable for various occasions;
disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a capacitive touch key detection circuit and a detection method thereof.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, a capacitive touch key detection circuit includes:
a first-order charge and discharge unit;
a second-order charge and discharge unit;
a filtering unit;
the key capacitor formed by the spring keys is connected between the first-order charge and discharge unit and the second-order charge and discharge unit;
the input signal charges and discharges the key capacitor through the first-order charging and discharging unit, the oscillation signal processed by the first-order charging and discharging unit charges and discharges through the second-order charging and discharging unit, and the oscillation signal is filtered by the filtering unit to form a stable voltage signal.
The further technical scheme is as follows: the first-order charging and discharging unit and the second-order charging and discharging unit have different charging and discharging frequencies.
The further technical scheme is as follows: the charging and discharging frequency of the first-order charging and discharging unit is higher than that of the second-order charging and discharging unit.
The further technical scheme is as follows: the first-order charging and discharging unit comprises a resistor R42 and a triode Q3, one end of the resistor R42 is connected with an input signal end, the other end of the resistor R42 is connected with a third pin of the triode Q3 and a key capacitor, and a second pin of the triode Q3 is connected with one end of a resistor R42 and the input signal end.
The further technical scheme is as follows: the second-order charging and discharging unit comprises a resistor R41, one end of the resistor R41 is connected with the third pin of the triode Q3 and the key capacitor, the other end of the resistor R41 is connected with the filtering unit, and the first pin of the triode Q3 is connected with the filtering unit.
The further technical scheme is as follows: the filtering unit comprises a resistor R47 and a capacitor C19, one end of the resistor R47 is connected with the first pin of the triode Q3 and the other end of the resistor R41, the other end of the resistor R47 is connected with a signal output end and one end of a capacitor C19, and the other end of the capacitor C19 is grounded.
In a second aspect, a detection method based on a capacitive touch key detection circuit, the method comprising:
receiving a steady-state voltage detected by a capacitive touch key detection circuit;
performing analog-to-digital conversion on the steady-state voltage;
performing digital filtering on the steady-state voltage subjected to analog-to-digital conversion to obtain a steady-state numerical value, and taking the numerical value as a reference voltage value;
scanning the voltage value of the touch key at regular time;
and if the deviation of the voltage value of the touch key scanned and found at a certain moment and the reference voltage value is larger than a set threshold value and reaches a preset duration time, judging that the touch key has a pressing action.
In a third aspect, a detection device based on a capacitive touch key detection circuit comprises a receiving module, an analog-to-digital conversion module, a digital filtering module, a timing scanning module and a judging module;
the receiving module is used for receiving the steady-state voltage detected by the capacitive touch key detection circuit;
the analog-to-digital conversion module is used for performing analog-to-digital conversion on the steady-state voltage;
the digital filtering module is used for carrying out digital filtering on the steady-state voltage subjected to analog-to-digital conversion to obtain a steady-state numerical value, and taking the numerical value as a reference voltage value;
the timing scanning module is used for scanning the voltage value of the touch key at regular time;
and the judging module is used for judging that the touch key has a pressing action at a certain moment if the deviation between the voltage value of the touch key scanned and found at the certain moment and the reference voltage value is greater than a set threshold value and reaches a preset duration time.
In a fourth aspect, a computer device comprises a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the method steps as described above when executing the computer program.
In a fifth aspect, a storage medium stores a computer program comprising program instructions which, when executed by a processor, cause the processor to perform the method steps as described above.
Compared with the prior art, the invention has the beneficial effects that: the invention processes the input oscillation signal through the constructed capacitive touch key detection circuit and then outputs a stable voltage signal, and identifies the current state of the touch key through the amplitude of the voltage signal, thereby not only having high detection precision, but also having adjustable oscillation frequency and being programmable and being suitable for various different occasions.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented according to the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more apparent, the following detailed description will be given of preferred embodiments.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic circuit diagram of a capacitive touch key detection circuit according to an embodiment of the present invention;
fig. 2 is a flowchart of a detection method based on a capacitive touch key detection circuit according to an embodiment of the present invention;
FIG. 3 is a schematic block diagram of a detection apparatus based on a capacitive touch key detection circuit according to an embodiment of the present invention;
FIG. 4 is a schematic block diagram of a computer device provided in accordance with an embodiment of the present invention;
FIG. 5 is a first set of experimental data provided in accordance with an embodiment of the present invention;
FIG. 6 is a second set of experimental data provided in accordance with an embodiment of the present invention;
FIG. 7 is a third set of experimental data provided in accordance with an embodiment of the present invention;
fig. 8 is experimental data four provided by an embodiment of the present invention.
Detailed Description
In order to more fully understand the technical content of the present invention, the technical solution of the present invention will be further described and illustrated with reference to the following specific embodiments, but not limited thereto.
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.
Compared with the traditional discrete detection scheme, the capacitive touch key driving detection scheme provided by the invention has the advantages of few detection devices, high detection precision, adjustable oscillation frequency, programmability and suitability for various different occasions. The invention is described below by means of specific embodiments.
The capacitive touch key detection circuit comprises a first-order charge and discharge unit, a second-order charge and discharge unit, a filter unit and a key capacitor formed by spring keys, wherein the key capacitor is connected between the first-order charge and discharge unit and the second-order charge and discharge unit; the input signal charges and discharges the key capacitor through the first-order charging and discharging unit, the oscillation signal processed by the first-order charging and discharging unit is charged and discharged through the second-order charging and discharging unit, and the stable voltage signal is formed after the oscillation signal is filtered by the filtering unit.
In this embodiment, the oscillation signal is provided by the MCU, and is subjected to current-limiting voltage-dividing through the resistor, and since the touch key has a capacitive characteristic, the oscillation voltage is subjected to current-limiting charging and discharging through the resistor and the diode for the capacitor, and finally enters the RC filter circuit for integration, and the oscillation signal is integrated into a stable analog voltage signal, and finally returns to the analog-to-digital detection module of the MCU, and the current state of the key is identified by the amplitude of the analog voltage signal.
In this embodiment, the first-order charge/discharge unit and the second-order charge/discharge unit have different charge/discharge frequencies. The charging and discharging frequency of the first-order charging and discharging unit is higher than that of the second-order charging and discharging unit.
As shown in fig. 1, the first-order charging/discharging unit includes a resistor R42 and a transistor Q3, one end of the resistor R42 is connected to the input signal terminal, the other end of the resistor R42 is connected to the third pin of the transistor Q3 and the key capacitor, and the second pin of the transistor Q3 is connected to one end of the resistor R42 and the input signal terminal. The second-order charge and discharge unit comprises a resistor R41, one end of a resistor R41 is connected with a third pin of the triode Q3 and the key capacitor, the other end of the resistor R41 is connected with the filtering unit, and a first pin of the triode Q3 is connected with the filtering unit. The filtering unit comprises a resistor R47 and a capacitor C19, one end of the resistor R47 is connected with the first pin of the triode Q3 and the other end of the resistor R41, the other end of the resistor R47 is connected with the signal output end and one end of the capacitor C19, and the other end of the capacitor C19 is grounded.
IN fig. 1, an oscillation signal is input from an IN terminal, the oscillation signal has a fixed frequency, for example, 100KHz and an amplitude of Vdd, the signal is connected to K1 through R42 and Q3, where K1 is a spring key and has a capacitance characteristic, so that K1 can be regarded as a key capacitor C1, the oscillation signal continuously charges C1 through Q3 and discharges through R42 to maintain a balanced state, which is a first-order charge-discharge state; meanwhile, the stable voltage of K1 is transmitted to the RC filter circuit composed of R47 and C19 through R41 to perform charging operation, and is discharged through Q3 at the same time, which is a second-order charging and discharging operation for the RC filter circuit; because the resistance values of R41 and R42 are different, the charging and discharging frequencies and bandwidths of the two orders are not consistent, the charging and discharging frequency of the first order is faster than that of the second order, and the oscillation signals enter RC filters after being charged and discharged by the two orders, are integrated into a stable voltage signal OUT, and are finally transmitted to an AD conversion module of the MCU for analog-to-digital conversion.
First order charge and discharge formula: v1＝V0+(Vdd-V0)*[1-exp(-t/R42*C1)]；
A second-order charge and discharge formula: v2＝V1+(Vdd-V1)*[1-exp(-t/R41*C1)]；
Voltage after filtering: Vout-V2+(Vdd-V2)*[1-exp(-t/R47*C19)]；
V0 is the initial voltage of the capacitor C1, Vdd is the full-charge voltage of the capacitor C1, that is, Vdd is Vin, V1 is the effective value of the steady-state voltage after first-order charging and discharging, V2 is the effective value of the steady-state voltage after second-order charging and discharging, and Vout is the voltage finally obtained after RC filtering.
The specific embodiment of the present invention further provides a detection method based on the above capacitive touch key detection circuit, as shown in fig. 2, the method includes the following steps: s10, S20, S30, S40 and S50.
S10, receiving the steady-state voltage detected by the capacitive touch key detection circuit;
s20, performing analog-to-digital conversion on the steady-state voltage;
s30, performing digital filtering on the analog-to-digital converted steady-state voltage to obtain a steady-state numerical value, and taking the numerical value as a reference voltage value;
s40, scanning the voltage value of the touch key at regular time;
and S50, if the deviation between the voltage value of the touch key scanned and found at a certain moment and the reference voltage value is larger than a set threshold value and reaches a preset duration, judging that the touch key has a pressing action.
For steps S10 to S50, the steady-state voltage obtained by the detection circuit is converted into a digital quantity, i.e., an AD value, after analog-to-digital conversion (ADC), and digital filtering is performed to obtain a steady-state value, which can be regarded as a reference value Vref at the standby time of the touch key, and if a panel material is added to cover the spring, Vref1 changes in Vref, and can be identified by the size of Δ Vref (Δ Vref — Vref 1); the voltage value of the key is scanned at regular time, if the deviation delta Vref2 (delta Vref2 is Vref-V _ key) between the voltage value V _ key and the reference value obtained at a certain moment is larger than a set threshold value, and the delta Vref2 can maintain a preset duration (the duration can be set according to the actual situation), software can recognize that the touch key has a pressing action, and after the key has the pressing action, the software provides support for the subsequent corresponding functional reaction processing.
FIG. 5 is a waveform diagram of a fixed frequency oscillating voltage signal (amplitude of 5V), a first order charge-discharge signal, a second order charge-discharge signal, and a voltage after RC filtering; it can be seen that the fixed frequency oscillation voltage is integrated into a stable voltage with an amplitude of 2.06V through two-stage charging and discharging and RC filtering.
Fig. 6 shows the voltage change condition when there is a key press, and it can be seen that when there is a key press, the voltage after RC filtering has an obvious change, and when the key press recovers, the voltage also falls back to recover.
Fig. 7 and fig. 8 show MCU real-time test data, and it can be seen from the above figure that when there is no key operation, the value detected by the MCU is 1070 to 1090, when there is a key operation time, the maximum value rises to 2400, and when there is no key operation, the voltage also falls back and recovers.
The specific embodiment of the invention also provides a detection device based on the capacitive touch key detection circuit.
As shown in fig. 3, the detection apparatus 100 based on the capacitive touch key detection circuit includes a receiving module 110, an analog-to-digital conversion module 120, a digital filtering module 130, a timing scanning module 140, and a determination module 150;
the receiving module 110 is configured to receive the steady-state voltage detected by the capacitive touch key detection circuit.
And an analog-to-digital conversion module 120, configured to perform analog-to-digital conversion on the steady-state voltage.
And the digital filtering module 130 is configured to perform digital filtering on the analog-to-digital converted steady-state voltage to obtain a steady-state value, and use the value as a reference voltage value.
And the timing scanning module 140 is used for scanning the voltage value of the touch key at a timing.
The determining module 150 is configured to determine that the touch key has a pressing action at a certain time if a deviation between the voltage value of the touch key scanned and found at the certain time and the reference voltage value is greater than a set threshold and reaches a preset duration.
After analog-to-digital conversion (ADC) is carried out on the steady-state voltage obtained by the detection circuit, the steady-state voltage is converted into a digital quantity, namely an AD value, and digital filtering is carried out on the digital quantity to obtain a steady-state value, the value can be regarded as a reference value Vref at the standby time of the touch key, if a panel material is added to cover a spring, Vref can be changed to Vref1, and the value can be identified through the size of delta Vref (delta Vref is Vref-Vref 1); the voltage value of the key is scanned at regular time, if the deviation delta Vref2 (delta Vref2 is Vref-V _ key) between the voltage value V _ key and the reference value obtained at a certain moment is found to be larger than a set threshold, and the delta Vref2 can maintain a preset duration (the duration can be set according to the actual situation), software can recognize that the touch key is pressed, and after the key is pressed, the software can provide support for the subsequent corresponding functional reaction processing.
FIG. 5 is a waveform diagram of a fixed frequency oscillating voltage signal (amplitude of 5V), a first order charge-discharge signal, a second order charge-discharge signal, and a voltage after RC filtering; it can be seen that the fixed frequency oscillation voltage is integrated into a stable voltage with an amplitude of 2.06V through two-stage charging and discharging and RC filtering.
Fig. 6 shows the voltage change condition when there is a key press, and it can be seen that when there is a key press, the voltage after RC filtering has an obvious change, and when the key press recovers, the voltage also falls back to recover.
Fig. 7 and 8 show MCU real-time test data, and it can be seen from the above figures that when no key is pressed, the value detected by the MCU is 1070 to 1090, when the key is pressed, the maximum value rises to 2400, and when no key is pressed, the voltage also falls back and recovers.
As shown in fig. 4, the embodiment of the present invention further provides a computer device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the steps of the detection method based on the capacitive touch key detection circuit are implemented.
The computer device 700 may be a terminal or a server. The computer device 700 includes a processor 720, memory, and a network interface 750, which are connected by a system bus 710, where the memory may include non-volatile storage media 730 and internal memory 740.
The non-volatile storage medium 730 may store an operating system 731 and computer programs 732. The computer program 732, when executed, may cause the processor 720 to perform any of a variety of detection methods based on capacitive touch key detection circuitry.
The processor 720 is used to provide computing and control capabilities, supporting the operation of the overall computer device 700.
The internal memory 740 provides an environment for the operation of the computer program 732 in the non-volatile storage medium 730, and when the computer program 732 is executed by the processor 720, the processor 720 can execute any detection method based on the capacitive touch key detection circuit.
The network interface 750 is used for network communication such as sending assigned tasks and the like. Those skilled in the art will appreciate that the configuration shown in fig. 4 is a block diagram of only a portion of the configuration associated with the present application and does not constitute a limitation of the computing device 700 upon which the present application may be implemented, and that a particular computing device 700 may include more or less components than those shown, or may combine certain components, or have a different arrangement of components. Wherein the processor 720 is configured to execute the program code stored in the memory to perform the following steps:
receiving a steady-state voltage detected by a capacitive touch key detection circuit;
performing analog-to-digital conversion on the steady-state voltage;
performing digital filtering on the steady-state voltage subjected to analog-to-digital conversion to obtain a steady-state numerical value, and taking the numerical value as a reference voltage value;
scanning the voltage value of the touch key at regular time;
and if the deviation of the voltage value of the touch key scanned and found at a certain moment and the reference voltage value is larger than a set threshold value and reaches a preset duration time, judging that the touch key has a pressing action.
It should be understood that, in the embodiment of the present Application, the Processor 720 may be a Central Processing Unit (CPU), and the Processor 720 may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other Programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. Wherein a general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
Those skilled in the art will appreciate that the configuration of computer device 700 depicted in FIG. 4 is not intended to be limiting of computer device 700 and may include more or less components than those shown, or some components in combination, or a different arrangement of components.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present invention may be implemented in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, a network device, or the like) or a processor (processor) to execute all or part of the steps of the methods according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
It will be clear to those skilled in the art that, for convenience and simplicity of description, the foregoing division of the functional modules is merely illustrated, and in practical applications, the above function distribution may be performed by different functional modules according to needs, that is, the internal structure of the apparatus is divided into different functional modules to perform all or part of the above described functions. Each functional module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional modules are only used for distinguishing one functional module from another, and are not used for limiting the protection scope of the application. The specific working process of the modules in the apparatus may refer to the corresponding process in the foregoing method embodiment, and is not described herein again.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
In the embodiments provided in the present invention, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described device embodiments are merely illustrative, and for example, the division of the modules is only one logical functional division, and other divisions may be realized in practice, for example, multiple units or components may be combined or integrated into another device, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The modules described as separate parts may or may not be physically separate, and parts displayed as modules may or may not be physical modules, may be located in one place, or may be distributed on a plurality of network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.
While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. Capacitive touch key detection circuitry, characterized by comprising:
a first-order charge and discharge unit;
a second-order charge and discharge unit;
a filtering unit;
the key capacitor formed by the spring keys is connected between the first-order charge and discharge unit and the second-order charge and discharge unit;
the input signal charges and discharges the key capacitor through the first-order charging and discharging unit, the oscillation signal processed by the first-order charging and discharging unit charges and discharges through the second-order charging and discharging unit, and the oscillation signal is filtered by the filtering unit to form a stable voltage signal.
2. The capacitive touch key detection circuit according to claim 1, wherein the first order charge and discharge unit and the second order charge and discharge unit have different charge and discharge frequencies.
3. The circuit of claim 2, wherein the first-order charge/discharge unit has a higher charge/discharge frequency than the second-order charge/discharge unit.
4. The capacitive touch key detection circuit according to claim 1, wherein the first-order charge/discharge unit comprises a resistor R42 and a transistor Q3, one end of the resistor R42 is connected to the input signal terminal, the other end of the resistor R42 is connected to the third pin of the transistor Q3 and the key capacitor, and the second pin of the transistor Q3 is connected to one end of a resistor R42 and the input signal terminal.
5. The capacitive touch key detection circuit according to claim 4, wherein the second-order charging/discharging unit comprises a resistor R41, one end of the resistor R41 is connected to the third pin of the transistor Q3 and the key capacitor, the other end of the resistor R41 is connected to the filtering unit, and the first pin of the transistor Q3 is connected to the filtering unit.
6. The capacitive touch key detection circuit according to claim 5, wherein the filtering unit comprises a resistor R47 and a capacitor C19, one end of the resistor R47 is connected to the first pin of the transistor Q3 and the other end of the resistor R41, the other end of the resistor R47 is connected to a signal output terminal and one end of a capacitor C19, and the other end of the capacitor C19 is grounded.
7. The detection method based on the capacitive touch key detection circuit is characterized by comprising the following steps:
receiving a steady-state voltage detected by a capacitive touch key detection circuit;
performing analog-to-digital conversion on the steady-state voltage;
performing digital filtering on the steady-state voltage subjected to analog-to-digital conversion to obtain a steady-state numerical value, and taking the numerical value as a reference voltage value;
scanning the voltage value of the touch key at regular time;
and if the deviation of the voltage value of the touch key scanned and found at a certain moment and the reference voltage value is larger than a set threshold value and reaches a preset duration time, judging that the touch key has a pressing action.
8. The detection device based on the capacitive touch key detection circuit is characterized by comprising a receiving module, an analog-to-digital conversion module, a digital filtering module, a timing scanning module and a judging module;
the receiving module is used for receiving the steady-state voltage detected by the capacitive touch key detection circuit;
the analog-to-digital conversion module is used for performing analog-to-digital conversion on the steady-state voltage;
the digital filtering module is used for carrying out digital filtering on the steady-state voltage subjected to analog-to-digital conversion to obtain a steady-state numerical value, and taking the numerical value as a reference voltage value;
the timing scanning module is used for scanning the voltage value of the touch key at regular time;
and the judging module is used for judging that the touch key has a pressing action at a certain moment if the deviation between the voltage value of the touch key scanned and found at the certain moment and the reference voltage value is greater than a set threshold value and reaches a preset duration time.
9. A computer arrangement comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the method steps of claim 7 when executing the computer program.
10. A storage medium, characterized in that the storage medium stores a computer program comprising program instructions which, when executed by a processor, cause the processor to carry out the method steps according to claim 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111647909.2A CN114337634A (en) | 2021-12-30 | 2021-12-30 | Capacitive touch key detection circuit and detection method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111647909.2A CN114337634A (en) | 2021-12-30 | 2021-12-30 | Capacitive touch key detection circuit and detection method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114337634A true CN114337634A (en) | 2022-04-12 |
Family
ID=81017733
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111647909.2A Pending CN114337634A (en) | 2021-12-30 | 2021-12-30 | Capacitive touch key detection circuit and detection method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114337634A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114895809A (en) * | 2022-07-14 | 2022-08-12 | 深圳贝特莱电子科技股份有限公司 | Improve anti-jamming capability's spaced touch circuit, touch button and touch product |
-
2021
- 2021-12-30 CN CN202111647909.2A patent/CN114337634A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114895809A (en) * | 2022-07-14 | 2022-08-12 | 深圳贝特莱电子科技股份有限公司 | Improve anti-jamming capability's spaced touch circuit, touch button and touch product |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105379120B (en) | It is detected using Δ/Σ conversion capacitive proximity | |
| JP5669850B2 (en) | Capacitive touch sensor device setting system and method | |
| CN101213461B (en) | Methods and systems for detecting a capacitance using SIGMA-DELTA measurement techniques | |
| US8665224B2 (en) | Capacitance touch sensor | |
| US20160063301A1 (en) | Capacitive fingerprint sensor and fingerprint sensing method thereof | |
| US11609664B2 (en) | Capacitance detection circuit, sensor, chip and electronic device | |
| CN104794433A (en) | Fingerprint recognition system and fingerprint recognition method | |
| EP3324331B1 (en) | Capacitive sensing circuit | |
| CN102968224A (en) | Control circuit and control method of touch panel | |
| CN114337634A (en) | Capacitive touch key detection circuit and detection method thereof | |
| US20030179123A1 (en) | Analog-to-digital conversion using a counter | |
| EP3469467A1 (en) | Detection of piezoelectric sensor elements | |
| CN114356145A (en) | Touch detection circuit, touch device and electronic equipment | |
| KR101216813B1 (en) | Capacity determining circuit, touch switch including the capacity determining circuit | |
| CN106033964B (en) | Button triggers detection device and has its domestic appliance among domestic appliance | |
| US8878556B2 (en) | Sensing device and method | |
| US10198094B1 (en) | Active stylus | |
| CN217085101U (en) | Capacitance detection circuit, touch control chip and electronic equipment | |
| CN212872665U (en) | Capacitance change detection circuit | |
| CN116203411A (en) | Touch key capacitance detection method and system applied to MCU | |
| CN114487784A (en) | Capacitance detection circuit, touch chip and electronic equipment | |
| CN103576999A (en) | Sensing device of capacitive touch panel | |
| CN110460326B (en) | Touch key interface circuit and touch key monitoring system | |
| KR102632360B1 (en) | Dual slope analog to digital converter with parallel counting structure | |
| CN117723842A (en) | Capacitance detection circuit, detection method, detection device and detection equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |