CN114217705B - Touch detection circuit and detection method - Google Patents
Touch detection circuit and detection method Download PDFInfo
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- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
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Abstract
The application provides a touch detection circuit and a detection method, wherein a detection module outputs pulse waveforms according to capacitance changes of an environment capacitor and a finger touch capacitor and counts the number of pulses; outputting a high-level touch signal when the pulse number is smaller than a preset value, and outputting a low-level touch signal when the pulse number is greater than or equal to the preset value; and when the pulse number is larger than or equal to the preset value, updating the preset value according to the change of the pulse waveform output by the environment capacitor at intervals of preset time. According to the application, the preset value is updated according to the change of the pulse waveform output by the environmental capacitor at intervals of preset time, so that the preset value changes along with the change of the capacitance of the environmental capacitor, the touch detection result is not easily affected by the environmental change, the detection accuracy is improved, and the user experience is improved.
Description
Technical Field
The application belongs to the technical field of touch detection, and particularly relates to a touch detection circuit and a detection method.
Background
The touch detection is a detection method for judging whether a finger touches or not and performing corresponding algorithm processing by detecting capacitance change after the finger touches a touch point. Touch detection is widely applied to various electronic products requiring finger touch operation, so that the service life, waterproof performance, safety, appearance design and the like of the electronic products are improved.
However, the touch point of the existing touch detection circuit generally comprises an environmental capacitor and a finger touch capacitor, wherein the capacitance of the environmental capacitor is easily affected by environments on different application circuit boards, so that the detection accuracy is reduced, and even false triggering behaviors occur, and the user operation is affected.
Disclosure of Invention
The application aims to provide a touch detection circuit and a detection method, and aims to solve the problem that the traditional touch detection circuit is easily affected by environment.
In order to achieve the above object, in a first aspect, an embodiment of the present application provides a touch detection circuit, including a detection module and a control module;
The detection module is electrically connected with the control module;
The detection module is configured to output pulse waveforms according to capacitance changes of the environment capacitance and the finger touch capacitance and count the number of pulses;
the control module is configured to output a high-level touch signal when the pulse number is smaller than a preset value, and output a low-level touch signal when the pulse number is larger than or equal to the preset value; and updating the preset value according to the change of the pulse waveform output by the environment capacitor every interval preset time when the pulse number is larger than or equal to the preset value.
In a possible implementation manner of the first aspect, the detection module includes a first detection unit;
The first detection unit is electrically connected with the control module;
The first detection unit is configured to output a first pulse waveform according to capacitance changes of the environment capacitance and the finger touch capacitance and count a first pulse number;
The control module is configured to output a high-level touch signal when the first pulse number is smaller than a preset value, and output a low-level touch signal when the first pulse number is larger than or equal to the preset value, wherein the preset value is updated according to the change of a first pulse waveform output by the environment capacitor every preset time.
In another possible implementation manner of the first aspect, the detection module includes a second detection unit and a third detection unit;
The second detection unit is electrically connected with the third detection unit and the control module;
the second detection unit is configured to output a second pulse waveform according to the capacitance changes of the environment capacitance and the finger touch capacitance and count a second pulse number;
The third detection unit is configured to output a third pulse waveform according to the second pulse waveform and count a third pulse number;
the control module is configured to output a high-level touch signal when the third pulse number is smaller than a preset value, and output a low-level touch signal when the third pulse number is larger than or equal to the preset value, and update the preset value according to the change of a second pulse waveform output by the environment capacitor every preset time.
In another possible implementation manner of the first aspect, the first detection unit includes a first capacitor, a first current source, a first switch, a second capacitor, a second switch, a second current source, a first comparator, and a first pulse counter;
One end of the first capacitor is electrically connected with the touch point, the positive electrode of the first current source, one end of the second capacitor, one end of the second switch and the input end of the first comparator, the negative electrode of the first current source is electrically connected with one end of the first switch, the other end of the first switch is electrically connected with the control module and the first power supply, the other end of the second switch is electrically connected with the control module and the negative electrode of the second current source, the other end of the first capacitor, the other end of the second capacitor and the positive electrode of the second current source are all grounded, the output end of the first comparator is electrically connected with the input end of the first pulse counter, and the output end of the first pulse counter is electrically connected with the control module.
In another possible implementation manner of the first aspect, the second detection unit includes a third capacitor, a third current source, a third switch, a fourth capacitor, a fourth switch, a fourth current source, a second comparator, and a second pulse counter;
One end of the third capacitor is electrically connected with the touch point, the positive electrode of the third current source, one end of the fourth capacitor, one end of the fourth switch and the input end of the second comparator, the negative electrode of the third current source is electrically connected with one end of the third switch, the other end of the third switch is electrically connected with the control module and the second power supply, the other end of the fourth switch is electrically connected with the control module and the negative electrode of the fourth current source, the other end of the third capacitor, the other end of the fourth capacitor and the positive electrode of the fourth current source are all grounded, the output end of the second comparator is electrically connected with the input end of the second pulse counter, and the output end of the second pulse counter is electrically connected with the control module.
In another possible implementation manner of the first aspect, the third detection unit includes a fifth capacitor, a fifth switch, a fifth current source, a sixth switch, a sixth current source, a third comparator, and a third pulse counter;
One end of the fifth capacitor is electrically connected with the positive electrode of the fifth current source, one end of the sixth switch and the input end of the third comparator, the negative electrode of the fifth current source is electrically connected with one end of the fifth switch, the other end of the fifth switch is electrically connected with the output end of the second comparator and the third power supply, the other end of the sixth switch is electrically connected with the output end of the second comparator and the negative electrode of the sixth current source, the other end of the fifth capacitor and the positive electrode of the sixth current source are grounded, the output end of the third comparator is electrically connected with the input end of the third pulse counter, and the output end of the third pulse counter is electrically connected with the control module.
In a second aspect, an embodiment of the present application provides a detection method of a touch detection circuit, including:
outputting pulse waveforms according to the capacitance changes of the environment capacitance and the finger touch capacitance and counting the pulse number;
And outputting a high-level touch signal when the pulse number is smaller than a preset value, and outputting a low-level touch signal when the pulse number is larger than or equal to the preset value, wherein the preset value is updated according to the change of the pulse waveform output by the environment capacitor at intervals of preset time.
In another possible implementation manner of the second aspect, the outputting the pulse waveform according to the capacitance changes of the environmental capacitance and the finger touch capacitance and counting the pulse number includes:
outputting a first pulse waveform according to the capacitance changes of the environment capacitance and the finger touch capacitance and counting a first pulse number;
Or outputting a second pulse waveform and counting the second pulse number according to the capacitance changes of the environment capacitance and the finger touch capacitance, and outputting a third pulse waveform and counting the third pulse number according to the second pulse waveform.
In another possible implementation manner of the second aspect, the outputting the high-level touch signal when the pulse number is less than the preset value and outputting the low-level touch signal when the pulse number is greater than or equal to the preset value includes:
Outputting a high-level touch signal when the first pulse number is smaller than the preset value, and outputting a low-level touch signal when the first pulse number is greater than or equal to the preset value;
or outputting a high-level touch signal when the third pulse number is less than the preset value, and outputting a low-level touch signal when the third pulse number is greater than or equal to the preset value.
In another possible implementation manner of the second aspect, the updating the preset value according to the change of the pulse waveform output by the environmental capacitor at preset time intervals includes:
And updating the preset value to the pulse number of the pulse waveform of the low-level touch signal output according to the environment capacitance every preset time interval.
Compared with the prior art, the embodiment of the application has the beneficial effects that: according to the touch detection circuit, the detection module outputs pulse waveforms according to the capacitance changes of the environment capacitance and the finger touch capacitance and counts the pulse numbers; outputting a high-level touch signal when the pulse number is smaller than a preset value, and outputting a low-level touch signal when the pulse number is greater than or equal to the preset value; and when the pulse number is larger than or equal to the preset value, updating the preset value according to the change of the pulse waveform output by the environment capacitor at intervals of preset time. According to the application, the preset value is updated according to the change of the pulse waveform output by the environmental capacitor at intervals of preset time, so that the preset value changes along with the change of the capacitance of the environmental capacitor, the touch detection result is not easily affected by the environmental change, the detection accuracy is improved, and the user experience is improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments or the description of the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic diagram of an overall structure of a touch detection circuit according to an embodiment of the present application;
Fig. 2 is a schematic diagram of a first structure of a touch detection circuit according to an embodiment of the present application;
FIG. 3 is a schematic diagram of a second structure of a touch detection circuit according to an embodiment of the present application;
FIG. 4 is a circuit diagram of a first configuration of a touch detection circuit according to an embodiment of the present application;
FIG. 5 is a circuit diagram of a second configuration of a touch detection circuit according to an embodiment of the present application;
fig. 6 is a flowchart of a detection method of a touch detection circuit according to an embodiment of the present application.
Reference numerals illustrate:
1-detection module, 11-first detection unit, 12-second detection unit, 13-third detection unit, 2-control module.
Detailed Description
In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
At present, a touch point of a traditional touch detection circuit generally comprises an environmental capacitance and a finger touch capacitance, and the touch detection circuit is arranged on different application circuit boards, so that the environmental capacitance generates different capacitance, and the touch detection result is easily influenced by the environmental capacitance, and the problems of reduced sensitivity, false triggering and the like are caused.
Therefore, the application provides a touch detection circuit, wherein the control module updates the preset value according to the change of the pulse waveform output by the environmental capacitor at intervals of preset time, so that the preset value changes along with the change of the capacitance of the environmental capacitor, and the accuracy of a touch detection result is improved.
The touch detection circuit provided by the application is described in an exemplary manner with reference to the accompanying drawings: fig. 1 is a schematic diagram of the overall structure of a touch detection circuit according to an embodiment of the present application, as shown in fig. 1, for convenience of explanation, only the portion related to the embodiment is shown, and the details are as follows: illustratively, the touch detection circuit 100, electrically connected to the touch point 200, may include a detection module 1 and a control module 2;
the detection module 1 is electrically connected with the control module 2;
a detection module 1 configured to output a pulse waveform according to capacitance changes of the environmental capacitance and the finger touch capacitance and count the number of pulses;
A control module 2 configured to output a high-level touch signal when the number of pulses is less than a preset value, and to output a low-level touch signal when the number of pulses is greater than or equal to the preset value; and updating the preset value according to the change of the pulse waveform output by the environment capacitor at intervals of preset time when the pulse number is larger than or equal to the preset value.
In the embodiment of the application, firstly, a detection module outputs pulse waveforms according to capacitance changes of an environment capacitor and a finger touch capacitor and counts the number of pulses, then, a control module compares the number of pulses with a preset value, and when the number of pulses is smaller than the preset value, a high-level touch signal is output to indicate that the finger touch is performed; outputting a low-level touch signal when the pulse number is greater than or equal to a preset value, wherein the low-level touch signal indicates that no finger touch exists; meanwhile, the preset value is updated according to the change of the pulse waveform output by the environmental capacitor at each interval for preset time, so that the preset value changes along with the change of the environmental capacitor, the influence of the change of the environmental capacitor on detection accuracy caused by accidental factors is reduced, namely, when no finger touches, the capacitance detected by the detection module is the capacitance of the environmental capacitor and is the reference capacitance; when a finger touches, the capacitance detected by the detection module is the sum of the capacitance of the environment capacitance and the capacitance of the finger touch capacitance.
Meanwhile, when the pulse number is larger than or equal to a preset value, namely, when no finger touches, the reference capacitance is measured again every preset time, so that the capacitance of the finger touching capacitance is more accurate, and the additionally increased variation of the environmental capacitance is not overlapped.
Fig. 2 is a schematic diagram of a first structure of a touch detection circuit according to an embodiment of the present application, and as shown in fig. 2, the detection module 1 includes a first detection unit 11;
The first detection unit 11 is electrically connected with the control module 2;
A first detection unit 11 configured to output a first pulse waveform according to capacitance changes of the environmental capacitance and the finger touch capacitance and count a first pulse number;
The control module 2 is configured to output a high-level touch signal when the first pulse number is smaller than a preset value, and output a low-level touch signal when the first pulse number is larger than or equal to the preset value, and update the preset value according to the change of the first pulse waveform output by the environmental capacitor every preset time.
In the embodiment of the application, the detection module only comprises a first detection unit, the change of the capacitance of the environmental capacitance and the finger touch capacitance is detected in real time through the first detection unit, the first pulse number output by the first detection unit is compared with the preset value through the control module, and the high-level touch signal or the low-level signal is determined to be output, so that specific touch control is implemented, meanwhile, the preset value is updated according to the change of the first pulse waveform output by the environmental capacitance every interval preset time, the touch detection result is not easily influenced by the environmental change, and the detection accuracy is improved.
Fig. 3 is a schematic diagram of a second structure of a touch detection circuit according to an embodiment of the present application, and as shown in fig. 3, the detection module 1 includes a second detection unit 12 and a third detection unit 13;
the second detection unit 12 is electrically connected with the third detection unit 13 and the control module 2;
a second detection unit 12 configured to output a second pulse waveform according to the capacitance changes of the environmental capacitance and the finger touch capacitance and count a second pulse number;
A third detection unit 13 configured to output a third pulse waveform from the second pulse waveform and count a third pulse number;
and a control module 2 configured to output a high-level touch signal when the third pulse number is smaller than a preset value, and to output a low-level touch signal when the third pulse number is greater than or equal to the preset value, the preset value being updated according to a change in the second pulse waveform output by the environmental capacitor every preset time.
In the embodiment of the application, the detection module can comprise a second detection unit and a third detection unit, wherein the second detection unit outputs a second pulse waveform according to the capacitance changes of the environmental capacitance and the finger touch capacitance and counts the second pulse number, and the third detection unit outputs a third pulse waveform according to the second pulse waveform and counts the third pulse number, because the second detection unit isolates the third detection unit from the environmental capacitance, the pulse waveform of the third detection unit is not easy to generate false triggering behavior due to the short-term change of the environmental capacitance, and meanwhile, the capacitance change of a touch point after the finger touch can be effectively reflected. The control module compares the third pulse number output by the third detection unit with a preset value to determine to output a high-level touch signal or a low-level signal, so that specific touch control is implemented, meanwhile, the preset value is updated according to the change of the second pulse waveform output by the environment capacitor at each preset interval, the influence of the environment on the touch detection result on the application circuit board can be filtered, the influence of the transient change of the environment capacitor on the touch detection result can be filtered, and the detection accuracy is improved as a whole.
Fig. 4 is a circuit diagram of a first structure of a touch detection circuit according to an embodiment of the present application, as shown in fig. 4, the first detection unit 11 includes a first capacitor C1, a first current source I1, a first switch S1, a second capacitor C2, a second switch S2, a second current source I2, a first comparator, and a first pulse counter;
One end of a first capacitor C1 is electrically connected with a touch point, the anode of a first current source I1, one end of a second capacitor C2, one end of a second switch S2 and the input end of a first comparator, the cathode of the first current source I1 is electrically connected with one end of the first switch S1, the other end of the first switch S1 is electrically connected with a control module 2 and a first power supply VCC1, the other end of the second switch S2 is electrically connected with the control module and the cathode of the second current source I2, the other end of the first capacitor C1, the other end of the second capacitor C2 and the anode of the second current source I2 are all grounded, the output end of the first comparator is electrically connected with the input end of a first pulse counter, and the output end of the first pulse counter is electrically connected with the control module 2.
In the embodiment of the application, the touch point is an external structure and is used for sensing the touch of a finger and is electrically connected with the touch detection circuit through a pin. The first capacitor is an environmental capacitor and is used for sensing the change of the surrounding environment, the second capacitor is charged through the first switch and the first current source, the second capacitor is discharged through the second switch and the second current source, the frequency of opening and closing of the first switch and the second switch is controlled through the control module, the connection part of the second capacitor and the first comparator generates a waveform similar to a triangular wave, the triangular wave is compared with a first voltage value VREF_H and a second reference voltage value VREF_L preset in the first comparator, a high level is output when the triangular wave voltage is higher than the first voltage value VREF_H, a low level is output when the triangular wave voltage is smaller than the second reference voltage value VREF_L, square waves are formed, the number of the square waves is counted through the first pulse counter, and the number of the square waves is influenced by the size of charge and discharge current and the size of the charge and discharge capacitor.
When the user touches the touch point with the finger, the capacitance of the finger is superimposed on the second capacitance, so that the capacitance of the second capacitance is increased, the charging and discharging speed is reduced, the square wave frequency output by the first comparator is reduced, the number of square wave pulses is reduced in the same time, when the number of pulses is reduced to be smaller than a preset value, the first pulse counter outputs a high-level signal for detecting the finger touch, and when the number of pulses is restored to be higher than the preset value, the first pulse counter outputs a low-level signal for not detecting the finger touch.
Fig. 5 is a circuit diagram of a second structure of the touch detection circuit according to an embodiment of the present application, as shown in fig. 5, the second detection unit 12 includes, for example, a third capacitor C3, a third current source I3, a third switch S3, a fourth capacitor C4, a fourth switch S4, a fourth current source I4, a second comparator, and a second pulse counter;
One end of the third capacitor C3 is electrically connected with the touch point, the positive electrode of the third current source I3, one end of the fourth capacitor C4, one end of the fourth switch S4 and the input end of the second comparator, the negative electrode of the third current source I3 is electrically connected with one end of the third switch S3, the other end of the third switch S3 is electrically connected with the control module 2 and the second power supply, the other end of the fourth switch S4 is electrically connected with the control module 2 and the negative electrode of the fourth current source I4, the other end of the third capacitor C3, the other end of the fourth capacitor C4 and the positive electrode of the fourth current source I4 are all grounded, the output end of the second comparator is electrically connected with the input end of the second pulse counter, and the output end of the second pulse counter is electrically connected with the control module 2.
In the embodiment of the application, the third capacitor is an environmental capacitor and is used for sensing the change of the surrounding environment, the fourth capacitor is charged through the third switch and the third current source, the fourth capacitor is discharged through the fourth switch and the fourth current source, the frequency of opening and closing of the third switch and the fourth switch is controlled through the control module, the connection part of the fourth capacitor and the second comparator generates a waveform similar to a triangular wave, the triangular wave is compared with a first voltage value VREF_H and a second reference voltage value VREF_L preset in the interior through the second comparator, a high level is output when the triangular wave voltage is higher than the first voltage value VREF_H, a low level is output when the triangular wave voltage is smaller than the second reference voltage value VREF_L, square waves are formed, the number of the square waves is counted through the second pulse counter, and the number of the square waves is influenced by the magnitude of charge and discharge current and the magnitude of the charge and discharge capacitor.
As shown in fig. 5, the third detection unit 13 exemplarily includes a fifth capacitor C5, a fifth switch S5, a fifth current source I5, a sixth switch S6, a sixth current source I6, a third comparator, and a third pulse counter;
One end of a fifth capacitor C5 is electrically connected with the positive electrode of a fifth current source I5, one end of a sixth switch S6 and the input end of a third comparator, the negative electrode of the fifth current source I5 is electrically connected with one end of the fifth switch S5, the other end of the fifth switch S5 is electrically connected with the output end of the second comparator and a third power supply, the other end of the sixth switch S6 is electrically connected with the output end of the second comparator and the negative electrode of the sixth current source I6, the other end of the fifth capacitor C5 and the positive electrode of the sixth current source I6 are grounded, the output end of the third comparator is electrically connected with the input end of the third pulse counter, and the output end of the third pulse counter is electrically connected with the control module.
In the embodiment of the application, the square wave output by the second comparator is used as a control signal, the fifth capacitor is charged through the fifth switch and the fifth current source, the fifth capacitor is discharged through the sixth switch and the sixth current source, the opening and closing frequencies of the fifth switch and the sixth switch are controlled through the square wave output by the second comparator, the connection part of the fifth capacitor and the third comparator generates a waveform similar to a triangular wave, the triangular wave is compared with a first voltage value VREF_H and a second reference voltage value VREF_L preset in the inside through the third comparator, a high level is output when the triangular wave voltage is higher than the first voltage value VREF_H, a low level is output when the triangular wave voltage is lower than the second reference voltage value VREF_L, so that a new square wave is formed, and the number of the new square wave in a period of time is counted through the second pulse counter.
When the user touches the touch point with the finger, the capacitance of the finger is superimposed on the fourth capacitance, so that the capacitance of the fourth capacitance is increased, the charging and discharging speed is reduced, the square wave frequency output by the second comparator is reduced, the number of square wave pulses is reduced in the same time by the third comparator, when the number of pulses is reduced to be smaller than a preset value, the third pulse counter outputs a high-level signal for detecting the touch of the finger, and when the number of pulses is restored to be higher than the preset value, the third pulse counter outputs a low-level signal for not detecting the touch of the finger.
Fig. 6 is a flowchart of a detection method of a touch detection circuit according to an embodiment of the present application, as shown in fig. 6, and exemplary, this embodiment discloses a detection method of a touch detection circuit, including:
outputting pulse waveforms according to the capacitance changes of the environment capacitance and the finger touch capacitance and counting the pulse number;
And outputting a high-level touch signal when the pulse number is smaller than a preset value, and outputting a low-level touch signal when the pulse number is larger than or equal to the preset value, wherein the preset value is updated according to the change of the pulse waveform output by the environment capacitor at intervals of preset time.
In the embodiment of the application, firstly, pulse waveforms are output according to capacitance changes of an environment capacitor and a finger touch capacitor, the number of pulses is counted, then the number of pulses is compared with a preset value, and when the number of pulses is smaller than the preset value, a high-level touch signal is output to indicate that the finger touch is performed; and outputting a low-level touch signal when the pulse number is greater than or equal to a preset value, wherein the low-level touch signal indicates that no finger touch exists. Meanwhile, the preset value is updated according to the change of the pulse waveform output by the environmental capacitor at each interval preset time, so that the reference capacitor is updated at each interval preset time, the detection capacitance (sum of the reference capacitance and the capacitance of the finger touch capacitor) during finger touch is more accurate, the influence of the environmental change is not easy to occur, and the sensitivity of touch detection is improved.
Illustratively, outputting the pulse waveform and counting the number of pulses according to the capacitance changes of the ambient capacitance and the finger touch capacitance includes:
outputting a first pulse waveform according to the capacitance changes of the environment capacitance and the finger touch capacitance and counting the first pulse number;
or outputting a second pulse waveform and counting the second pulse number according to the capacitance changes of the environment capacitance and the finger touch capacitance, and outputting a third pulse waveform and counting the third pulse number according to the second pulse waveform.
In the embodiment of the present application, there are two ways to obtain the pulse number: the pulse number is obtained by directly detecting the pulse formed by the change of the finger touch capacitance, or the pulse number is obtained by secondarily detecting the secondary pulse formed by the change of the capacitance of the environment capacitance and the finger touch capacitance, so that the influence of the transient change of the environment capacitance on the pulse waveform is isolated, and the detection sensitivity is further improved.
Illustratively, outputting the high-level touch signal when the number of pulses is less than a preset value, and outputting the low-level touch signal when the number of pulses is greater than or equal to the preset value, includes:
Outputting a high-level touch signal when the first pulse number is smaller than a preset value, and outputting a low-level touch signal when the first pulse number is larger than or equal to the preset value;
Or outputting a high-level touch signal when the third pulse number is less than a preset value, and outputting a low-level touch signal when the third pulse number is greater than or equal to the preset value.
In the embodiment of the application, two ways of comparing the pulse numbers are also available: the number of directly detected pulses is compared with a preset value to determine a high-level touch signal or a low-level touch signal, or the number of secondarily detected pulses is compared with a preset value to determine a high-level touch signal or a low-level touch signal.
Illustratively, updating the preset value according to a change in the pulse waveform output by the ambient capacitance every interval preset time includes:
The preset value is updated to the pulse number of the pulse waveform of the low-level touch signal output according to the ambient capacitance every preset time.
In the embodiment of the application, the specific updating mode of the preset value is as follows: after the touch detection circuit is powered on, firstly counting the pulse number of the pulse waveform of the low-level touch signal output according to the ambient capacitance as a preset value, then counting the pulse number of the pulse waveform of the low-level touch signal output according to the ambient capacitance again every interval preset time, and taking the counted pulse number as the preset value again, so that the preset value is updated every interval preset time, the capacitance of the ambient capacitance can be always represented by the preset value, the sensitivity of the touch detection circuit is improved, the false triggering behavior is reduced, and the user experience is improved.
It should be understood that the sequence number of each step in the foregoing embodiment does not mean that the execution sequence of each process should be determined by the function and the internal logic, and should not limit the implementation process of the embodiment of the present application.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional units and modules is illustrated, and in practical application, the above-described functional distribution may be performed by different functional units and modules according to needs, i.e. the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-described functions. The functional units and modules in the embodiment may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit, where the integrated units may be implemented in a form of hardware or a form of a software functional unit. In addition, the specific names of the functional units and modules are only for distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working process of the units and modules in the above system may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.
In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.
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 solution. 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 application.
In the embodiments provided in the present application, it should be understood that the disclosed ups parallel operation redundancy system and method may be implemented in other manners. For example, the ups parallel redundancy system embodiments described above are merely illustrative, e.g., the division of modules or units is merely a logical function division, and there may be additional divisions of actual implementation, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.
Claims (8)
1. The touch detection circuit is characterized by comprising a detection module and a control module;
The detection module is electrically connected with the control module;
The detection module is configured to output pulse waveforms according to capacitance changes of the environment capacitance and the finger touch capacitance and count the number of pulses;
The control module is configured to output a high-level touch signal when the pulse number is smaller than a preset value, and output a low-level touch signal when the pulse number is larger than or equal to the preset value; when the pulse number is larger than or equal to the preset value, updating the preset value according to the change of the pulse waveform output by the environment capacitor at each preset time interval;
the detection module comprises a first detection unit;
The first detection unit is electrically connected with the control module;
The first detection unit is configured to output a first pulse waveform according to capacitance changes of the environment capacitance and the finger touch capacitance and count a first pulse number;
the control module is configured to output a high-level touch signal when the first pulse number is smaller than a preset value, and output a low-level touch signal when the first pulse number is larger than or equal to the preset value, wherein the preset value is updated according to the change of a first pulse waveform output by the environment capacitor every preset time;
Or alternatively
The detection module comprises a second detection unit and a third detection unit;
The second detection unit is electrically connected with the third detection unit and the control module;
the second detection unit is configured to output a second pulse waveform according to the capacitance changes of the environment capacitance and the finger touch capacitance and count a second pulse number;
The third detection unit is configured to output a third pulse waveform according to the second pulse waveform and count a third pulse number;
the control module is configured to output a high-level touch signal when the third pulse number is smaller than a preset value, and output a low-level touch signal when the third pulse number is larger than or equal to the preset value, and update the preset value according to the change of a second pulse waveform output by the environment capacitor every preset time.
2. The touch detection circuit of claim 1, wherein the first detection unit comprises a first capacitance, a first current source, a first switch, a second capacitance, a second switch, a second current source, a first comparator, and a first pulse counter;
One end of the first capacitor is electrically connected with a touch point, the positive electrode of the first current source, one end of the second capacitor, one end of the second switch and the input end of the first comparator, the negative electrode of the first current source is electrically connected with one end of the first switch, the other end of the first switch is electrically connected with the control module and the first power supply, the other end of the second switch is electrically connected with the control module and the negative electrode of the second current source, the other end of the first capacitor, the other end of the second capacitor and the positive electrode of the second current source are all grounded, the output end of the first comparator is electrically connected with the input end of the first pulse counter, and the output end of the first pulse counter is electrically connected with the control module.
3. The touch detection circuit of claim 1, wherein the second detection unit comprises a third capacitance, a third current source, a third switch, a fourth capacitance, a fourth switch, a fourth current source, a second comparator, and a second pulse counter;
One end of the third capacitor is electrically connected with the touch point, the positive electrode of the third current source, one end of the fourth capacitor, one end of the fourth switch and the input end of the second comparator, the negative electrode of the third current source is electrically connected with one end of the third switch, the other end of the third switch is electrically connected with the control module and the second power supply, the other end of the fourth switch is electrically connected with the control module and the negative electrode of the fourth current source, the other end of the third capacitor, the other end of the fourth capacitor and the positive electrode of the fourth current source are all grounded, the output end of the second comparator is electrically connected with the input end of the second pulse counter, and the output end of the second pulse counter is electrically connected with the control module.
4. The touch detection circuit of claim 3, wherein the third detection unit comprises a fifth capacitance, a fifth switch, a fifth current source, a sixth switch, a sixth current source, a third comparator, and a third pulse counter;
One end of the fifth capacitor is electrically connected with the positive electrode of the fifth current source, one end of the sixth switch and the input end of the third comparator, the negative electrode of the fifth current source is electrically connected with one end of the fifth switch, the other end of the fifth switch is electrically connected with the output end of the second comparator and the third power supply, the other end of the sixth switch is electrically connected with the output end of the second comparator and the negative electrode of the sixth current source, the other end of the fifth capacitor and the positive electrode of the sixth current source are grounded, the output end of the third comparator is electrically connected with the input end of the third pulse counter, and the output end of the third pulse counter is electrically connected with the control module.
5. A detection method applied to the touch detection circuit according to any one of claims 1 to 4, comprising:
outputting pulse waveforms according to the capacitance changes of the environment capacitance and the finger touch capacitance and counting the pulse number;
And outputting a high-level touch signal when the pulse number is smaller than a preset value, and outputting a low-level touch signal when the pulse number is larger than or equal to the preset value, wherein the preset value is updated according to the change of the pulse waveform output by the environment capacitor at intervals of preset time.
6. The method of detecting as claimed in claim 5, wherein outputting the pulse waveform and counting the number of pulses according to the capacitance variation of the ambient capacitance and the finger touch capacitance comprises:
outputting a first pulse waveform according to the capacitance changes of the environment capacitance and the finger touch capacitance and counting a first pulse number;
Or outputting a second pulse waveform and counting the second pulse number according to the capacitance changes of the environment capacitance and the finger touch capacitance, and outputting a third pulse waveform and counting the third pulse number according to the second pulse waveform.
7. The detection method according to claim 6, wherein the outputting of the high-level touch signal when the number of pulses is smaller than the preset value and outputting of the low-level touch signal when the number of pulses is greater than or equal to the preset value includes:
Outputting a high-level touch signal when the first pulse number is smaller than the preset value, and outputting a low-level touch signal when the first pulse number is greater than or equal to the preset value;
or outputting a high-level touch signal when the third pulse number is less than the preset value, and outputting a low-level touch signal when the third pulse number is greater than or equal to the preset value.
8. The detecting method according to claim 6 or 7, wherein updating the preset value according to a change in the pulse waveform output from the ambient capacitance every preset time interval comprises:
And updating the preset value to the pulse number of the pulse waveform of the low-level touch signal output according to the environment capacitance every preset time interval.
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