CN114217705A - Touch detection circuit and detection method - Google Patents
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Abstract
The application provides a touch detection circuit and a detection method, wherein a detection module outputs a pulse waveform 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 larger than or equal to the preset value; and meanwhile, when the pulse number is larger than or equal to a preset value, updating the preset value at preset intervals according to the change of the pulse waveform output by the environment capacitor. The preset value is updated according to the change of the pulse waveform output by the environment capacitor at the preset time interval, the preset value is changed along with the change of the capacitance of the environment capacitor, and therefore the touch detection result is not easily affected by the change of the environment, 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 a touch point and performing corresponding algorithm processing by detecting capacitance change after the finger touches the touch point. The touch detection is widely applied to various electronic products needing finger touch operation, so that the service life, the waterproof performance, the safety, the appearance design and the like of the electronic products are improved.
However, the touch point of the existing touch detection circuit generally includes an environmental capacitor and a finger touch capacitor, wherein the capacitance of the environmental capacitor is easily affected by the environments on different application circuit boards, so that the detection accuracy is reduced, and even a false trigger action occurs, which affects the user operation.
Disclosure of Invention
The application aims to provide a touch detection circuit and a detection method, and aims to solve the problem that a traditional touch detection circuit is easily influenced by the environment.
In order to achieve the above object, in a first aspect, an embodiment of the present application provides a touch detection circuit, which includes a detection module and a control module;
the detection module is electrically connected with the control module;
the detection module is configured to output a pulse waveform according to capacitance changes of the environment capacitor and the finger touch capacitor and count the number of pulses;
the control module is configured to output a high-level touch signal when the number of pulses is less than a preset value, and output a low-level touch signal when the number of pulses 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 at intervals of preset time according to the change of the pulse waveform output by the environment capacitor.
In one possible implementation of the first aspect, 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 capacitor and the finger touch capacitor 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, output a low-level touch signal when the first pulse number is greater than or equal to the preset value, and update the preset value according to the change of a first pulse waveform output by the environment capacitor at preset time intervals.
In another possible implementation 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 capacitance changes of the environment capacitor and the finger touch capacitor 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, output a low-level touch signal when the third pulse number is greater 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 at preset time intervals.
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;
the one end of first electric capacity with the touch point, the positive pole of first electric current source, the one end of second electric capacity the one end of second switch with the input of first comparator is all connected electrically, the negative pole of first electric current source with the one end electricity of first switch is connected, the other end of first switch with control module and first power electricity are connected, the other end of second switch with control module with the negative pole electricity of second electric current source is connected, the other end of first electric capacity the other end of second electric capacity with the positive pole of second electric current source all grounds, the output of first comparator with the input electricity of first pulse counter is connected, the output of first pulse counter with the control module electricity is connected.
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;
the one end of third electric capacity with the touch point, the positive pole of third current source, the one end of fourth electric capacity, the one end of fourth switch with the input of second comparator is all connected electrically, the negative pole of third current source with the one end electricity of third switch is connected, the other end of third switch with control module and second power electricity are connected, the other end of fourth switch with control module with the negative pole electricity of fourth current source is connected, the other end of third electric capacity the other end of fourth electric capacity with the positive pole of fourth current source all grounds, the output of second comparator with the input electricity of second pulse counter is connected, the output of second pulse counter with the control module electricity is connected.
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 anode of the fifth current source, one end of the sixth switch and the input end of the third comparator, the cathode 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 cathode of the sixth current source, the other end of the fifth capacitor and the anode 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 for a touch detection circuit, including:
outputting a pulse waveform according to the capacitance change of the environment capacitor and the finger touch capacitor and counting the pulse number;
and outputting a high-level touch signal when the pulse number is smaller than a preset value, outputting a low-level touch signal when the pulse number is larger than or equal to the preset value, and updating the preset value at preset intervals according to the change of the pulse waveform output by the environment capacitor.
In another possible embodiment of the second aspect, the outputting the pulse waveform and counting the number of pulses according to the capacitance change of the environment capacitance and the finger touch capacitance includes:
outputting a first pulse waveform according to the capacitance changes of the environment capacitor and the finger touch capacitor and counting a first pulse number;
or outputting a second pulse waveform and counting a second pulse number according to the capacitance change of the environment capacitor and the finger touch capacitor, and outputting a third pulse waveform and counting a third pulse number according to the second pulse waveform.
In another possible embodiment of the second aspect, the outputting a high-level touch signal when the number of pulses is less than the preset value and outputting a 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 larger than or equal to the preset value;
or outputting a high-level touch signal when the third pulse number is smaller than the preset value, and outputting a low-level touch signal when the third pulse number is larger 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 environment capacitor at every preset time interval includes:
and updating the preset value into the pulse number of the pulse waveform of the low-level touch signal output according to the environment capacitor at preset time intervals.
Compared with the prior art, the embodiment of the application has the advantages that: the touch detection circuit outputs pulse waveforms and counts the pulse number according to the capacitance change of the environment capacitor and the finger touch capacitor through the detection module; 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; and meanwhile, when the pulse number is larger than or equal to a preset value, updating the preset value at preset intervals according to the change of the pulse waveform output by the environment capacitor. The preset value is updated according to the change of the pulse waveform output by the environment capacitor at the preset time interval, the preset value is changed along with the change of the capacitance of the environment capacitor, and therefore the touch detection result is not easily affected by the change of the environment, the detection accuracy is improved, and the user experience is improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
Fig. 1 is a schematic overall structure diagram of a touch detection circuit according to an embodiment of the present disclosure;
fig. 2 is a schematic diagram of a first structure of a touch detection circuit according to an embodiment of the present disclosure;
fig. 3 is a schematic diagram of a second structure of a touch detection circuit according to an embodiment of the present disclosure;
fig. 4 is a circuit diagram of a first structure of a touch detection circuit according to an embodiment of the present application;
fig. 5 is a circuit diagram of a second structure 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.
Description of reference numerals:
1-detection module, 11-first detection unit, 12-second detection unit, 13-third detection unit, and 2-control module.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present 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 merely illustrative of the present application and are not intended to limit the present application.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.
At present, a touch point of a traditional touch detection circuit generally comprises an environment capacitor and a finger touch capacitor, and the touch detection circuit is installed on different application circuit boards, so that the environment capacitor generates different capacitances, and therefore the touch detection result is easily influenced by the environment capacitor, and the problems of sensitivity reduction or false triggering and the like are caused.
Therefore, the application provides a touch detection circuit, the preset value is updated according to the change of the pulse waveform output by the environment capacitor at every interval of the preset time through the control module, so that the preset value changes along with the change of the capacitance of the environment capacitor, and the accuracy of a touch detection result is improved.
The touch detection circuit provided by the present application is described in an exemplary manner with reference to the accompanying drawings: fig. 1 is a schematic diagram of an overall structure of a touch detection circuit provided in an embodiment of the present application, and as shown in fig. 1, for convenience of description, only parts related to the embodiment are shown, and detailed descriptions 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;
the detection module 1 is configured to output a pulse waveform according to capacitance changes of an environment capacitor and a finger touch capacitor 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 output a low-level touch signal when the number of pulses is greater than or equal to the preset value; and when the pulse number is larger than or equal to a preset value, updating the preset value at preset intervals according to the change of the pulse waveform output by the environment capacitor.
In the embodiment of the application, firstly, a pulse waveform is output through a detection module according to the capacitance change of an environment capacitor and a finger touch capacitor, the pulse number is counted, then the pulse number is compared with a preset value through a control module, and when the pulse number is smaller than the preset value, a high-level touch signal is output to indicate that the finger touches; 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 touches the touch panel; meanwhile, the preset value is updated according to the change of the pulse waveform output by the environment capacitor at preset time intervals, so that the preset value changes along with the change of the environment capacitor, and the influence of the change of the environment capacitor on the detection accuracy due to accidental factors is reduced, namely when no finger touches the environment capacitor, the capacitance detected by the detection module is the capacitance of the environment capacitor and is the reference capacitance; when a finger touches the touch screen, the capacitance detected by the detection module is the sum of the capacitance of the environment capacitor and the capacitance of the finger touch capacitor.
Meanwhile, when the number of pulses is larger than or equal to the preset value, namely when no finger touches, the reference capacitance is measured again at preset intervals, so that the capacitance of the finger touch capacitor is more accurate, and the additionally increased variation of the environment capacitor cannot be superposed.
Fig. 2 is a schematic diagram of a first structure of a touch detection circuit provided in the embodiment of the present application, and as shown in fig. 2, the detection module 1 exemplarily 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 and count a first number of pulses according to a capacitance change of the environment capacitance and the finger touch capacitance;
and the control module 2 is configured to output a high-level touch signal when the first pulse number is smaller than a preset value, output a low-level touch signal when the first pulse number is greater than or equal to the preset value, and update the preset value according to the change of the first pulse waveform output by the environment capacitor at preset intervals.
In this embodiment of the application, the detection module may only include the first detection unit, the capacitance change of the environmental capacitance and the finger touch capacitance is detected in real time by the first detection unit, the first pulse number output by the first detection unit is compared with the preset value by the control module, and the high-level touch signal or the low-level signal is determined to be output, so as to implement specific touch control, and meanwhile, the preset value is updated according to the change of the first pulse waveform output by the environmental capacitance at preset intervals, so that the touch detection result is not easily affected by the environmental change, and the detection accuracy is improved.
Fig. 3 is a schematic diagram of a second structure of the touch detection circuit provided in the embodiment of the present application, and as shown in fig. 3, the detection module 1 exemplarily 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 and count a second number of pulses according to capacitance changes of the environmental capacitance and the finger touch capacitance;
a third detection unit 13 configured to output a third pulse waveform from the second pulse waveform and count the number of third pulses;
and the control module 2 is configured to output a high-level touch signal when the third pulse number is smaller than a preset value, output a low-level touch signal when the third pulse number is greater than or equal to the preset value, and update the preset value according to the change of the second pulse waveform output by the environment capacitor at preset intervals.
In this embodiment of the application, the detection module may include two detection units, namely a second detection unit and a third detection unit, the second detection unit outputs a second pulse waveform and counts a second pulse number according to capacitance changes of the environmental capacitance and the finger touch capacitance, and the third detection unit outputs a third pulse waveform and counts a third pulse number according to the second pulse waveform, because the second detection unit isolates the third detection unit from the environmental capacitance, the pulse waveform of the third detection unit is not easily subjected to a false trigger behavior caused by transient changes of the environmental capacitance, and meanwhile, capacitance changes of a touch point after finger touch can be effectively reflected. The third pulse number output by the third detection unit is compared with a preset value through the control module, and a high-level touch signal or a low-level signal is determined to be output, so that specific touch control is implemented, meanwhile, the preset value is updated at preset intervals according to the change of a second pulse waveform output by the environment capacitor, the influence of the environment on a touch detection result on an 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 integrally improved.
Fig. 4 is a circuit diagram of a first structure of a touch detection circuit provided in the embodiment of the present application, and as shown in fig. 4, for example, 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 to the 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 the first comparator, the cathode of the first current source I1 is electrically connected to one end of a first switch S1, the other end of the first switch S1 is electrically connected to the control module 2 and the first power source VCC1, the other end of the second switch S2 is electrically connected to the control module and the cathode of a 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 to the input end of the first pulse counter, and the output end of the first pulse counter is electrically connected to the control module 2.
In the embodiment of the application, the touch point is an external structure and used for sensing the touch of a finger, and the touch point is electrically connected with the inside of 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 opening and closing frequency of the first switch and the second switch is controlled through the control module, so that the waveform approximate to triangular wave is generated at the joint of the second capacitor and the first comparator, the triangular wave is compared with a first voltage value VREF _ H and a second reference voltage value VREF _ L which are preset inside through a first comparator, outputs a high level when the triangular wave voltage is higher than a first voltage value VREF _ H, outputs a low level when the triangular wave voltage is lower than a second reference voltage value VREF _ L, therefore, square waves are formed, the number of the square waves in a period of time is counted through the first pulse counter, and the number of the square waves is influenced by the size of the charging and discharging current and the size of the charging and discharging capacitor.
When a user touches a touch point with a finger, the capacitance of the finger is superposed on the second capacitance, so that the capacitance of the second capacitance is increased, the charging and discharging speed is slowed, the square wave frequency output by the first comparator is reduced, the number of square wave pulses is reduced within the same time, when the number of pulses is reduced to be less 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 provided in the embodiment of the present application, and as shown in fig. 5, the second detection unit 12 exemplarily includes 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 a third capacitor C3 is electrically connected to the touch point, the anode of a third current source I3, one end of a fourth capacitor C4, one end of a fourth switch S4 and the input end of the second comparator, the cathode of the third current source I3 is electrically connected to one end of a third switch S3, the other end of the third switch S3 is electrically connected to the control module 2 and the second power supply, the other end of the fourth switch S4 is electrically connected to the control module 2 and the cathode of the fourth current source I4, the other end of the third capacitor C3, the other end of the fourth capacitor C4 and the anode of the fourth current source I4 are all grounded, the output end of the second comparator is electrically connected to the input end of the second pulse counter, and the output end of the second pulse counter is electrically connected to 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 opening and closing frequency of the third switch and the fourth switch is controlled through the control module, so that the waveform approximate to triangular wave is generated at the joint of the fourth capacitor and the second comparator, the triangular wave is compared with a first voltage value VREF _ H and a second reference voltage value VREF _ L which are preset inside through a second comparator, outputs a high level when the triangular wave voltage is higher than a first voltage value VREF _ H, outputs a low level when the triangular wave voltage is lower than a second reference voltage value VREF _ L, therefore, square waves are formed, the number of the square waves in a period of time is counted through the second pulse counter, and the number of the square waves is influenced by the size of the charging and discharging current and the size of the charging and discharging capacitor.
As shown in fig. 5, the third detecting 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 to the anode of the fifth current source I5, one end of a sixth switch S6 and the input end of the third comparator, the cathode of the fifth current source I5 is electrically connected to one end of the fifth switch S5, the other end of the fifth switch S5 is electrically connected to the output end of the second comparator and the third power supply, the other end of the sixth switch S6 is electrically connected to the output end of the second comparator and the cathode of the sixth current source I6, the other end of the fifth capacitor C5 and the anode of the sixth current source I6 are both grounded, the output end of the third comparator is electrically connected to the input end of the third pulse counter, and the output end of the third pulse counter is electrically connected to 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 frequency of opening and closing of the fifth switch and the sixth switch is controlled through the square wave output by the second comparator, so that a waveform similar to a triangular wave is generated at the joint of the fifth capacitor and the third comparator, the triangular wave is compared with a first voltage value VREF _ H and a second reference voltage value VREF _ L preset inside through the third comparator, a high level is output when the voltage of the triangular wave is higher than the first voltage value VREF _ H, a low level is output when the voltage of the triangular wave is smaller than the second reference voltage VREF _ L, so that a new square wave is formed, and the number of the new square waves in a period of time is counted through the second pulse counter.
When a user touches a touch point with a finger, the capacitance of the finger is superposed on the fourth capacitor, so that the capacitance of the fourth capacitor is increased, the charging and discharging speed is slowed, the square wave frequency output by the second comparator is reduced, the number of square wave pulses in the same time of the third comparator is reduced, when the number of pulses is reduced to be less than a preset value, the third 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 third pulse counter outputs a low level signal for not detecting the finger touch.
Fig. 6 is a flowchart of a detection method of a touch detection circuit provided in an embodiment of the present application, and as shown in fig. 6, the embodiment exemplarily discloses a detection method of a touch detection circuit, including:
outputting a pulse waveform according to the capacitance change of the environment capacitor and the finger touch capacitor and counting the pulse number;
and outputting a high-level touch signal when the pulse number is smaller than a preset value, outputting a low-level touch signal when the pulse number is larger than or equal to the preset value, and updating the preset value at preset intervals according to the change of a pulse waveform output by the environment capacitor.
In the embodiment of the application, firstly, a pulse waveform is output according to the capacitance changes of the environment capacitor and the finger touch capacitor, the pulse number is counted, then the pulse number is compared with a preset value, and when the pulse number is smaller than the preset value, a high-level touch signal is output to indicate that the finger touches; 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 touches the touch screen. Meanwhile, the preset value is updated at intervals of preset time according to the change of the pulse waveform output by the environment capacitor, so that the reference capacitor is updated at intervals of preset time, the detection capacitance (the sum of the reference capacitance and the capacitance of the finger touch capacitor) during finger touch is more accurate, the influence of environment change is not easily caused, and the sensitivity of touch detection is improved.
Illustratively, outputting a pulse waveform and counting the number of pulses according to the capacitance change of the ambient capacitance and the finger touch capacitance includes:
outputting a first pulse waveform according to the capacitance change of the environment capacitor and the finger touch capacitor and counting the number of first pulses;
or outputting a second pulse waveform according to the capacitance change of the environment capacitor and the finger touch capacitor and counting a second pulse number, and outputting a third pulse waveform according to the second pulse waveform and counting a third pulse number.
In the embodiment of the present application, there are two ways to obtain the number of pulses: the pulse formed by the change of the finger touch capacitance is directly detected to obtain the pulse number, or the secondary pulse formed by the change of the capacitance of the secondary detection environment capacitance and the finger touch capacitance is detected to obtain the pulse number, 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 a high-level touch signal when the number of pulses is less than a preset value and outputting a 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, when the third pulse number is less than a preset value, a high-level touch signal is output, and when the third pulse number is greater than or equal to the preset value, a low-level touch signal is output.
In the embodiment of the present application, there are two methods of comparing the pulse numbers: and comparing the directly detected pulse number with a preset value to determine a high-level touch signal or a low-level touch signal, or comparing the secondarily detected pulse number with the preset value to determine the high-level touch signal or the low-level touch signal.
Illustratively, the updating of the preset value according to the change of the pulse waveform output by the environment capacitor at preset time intervals comprises:
and updating the preset value into the pulse number of the pulse waveform of the low-level touch signal output according to the environment capacitor at preset time intervals.
In the embodiment of the present application, the specific updating manner of the preset value is as follows: after the touch detection circuit is powered on, firstly, the pulse number of the pulse waveform of the low-level touch signal output according to the environment capacitor is counted to be used as a preset value, then, every interval of preset time, the pulse number of the pulse waveform of the low-level touch signal output according to the environment capacitor is counted again and is used as the preset value again, and therefore, the preset value is updated every interval of preset time, the preset value can always reflect the capacitance of the environment capacitor, 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 numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules, so as to perform all or part of the functions described above. Each functional unit and 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 units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.
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 application.
In the embodiments provided in the present application, it should be understood that the disclosed uninterruptible power supply parallel redundancy system and method may be implemented in other ways. For example, the ups parallel redundancy system embodiments described above are merely illustrative, and for example, a division of modules or units is merely a logical division, and in practice, there may be other divisions, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not implemented. 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.
Units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.
Claims (10)
1. A 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 a pulse waveform according to capacitance changes of the environment capacitor and the finger touch capacitor and count the number of pulses;
the control module is configured to output a high-level touch signal when the number of pulses is less than a preset value, and output a low-level touch signal when the number of pulses 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 at intervals of preset time according to the change of the pulse waveform output by the environment capacitor.
2. The touch detection circuit of claim 1, wherein 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 capacitor and the finger touch capacitor 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, output a low-level touch signal when the first pulse number is greater than or equal to the preset value, and update the preset value according to the change of a first pulse waveform output by the environment capacitor at preset time intervals.
3. The touch detection circuit of claim 1, wherein 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 capacitance changes of the environment capacitor and the finger touch capacitor 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, output a low-level touch signal when the third pulse number is greater 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 at preset time intervals.
4. The touch detection circuit of claim 2, wherein the first detection unit comprises 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;
the one end of first electric capacity with the touch point, the positive pole of first electric current source, the one end of second electric capacity the one end of second switch with the input of first comparator is all connected electrically, the negative pole of first electric current source with the one end electricity of first switch is connected, the other end of first switch with control module and first power electricity are connected, the other end of second switch with control module with the negative pole electricity of second electric current source is connected, the other end of first electric capacity the other end of second electric capacity with the positive pole of second electric current source all grounds, the output of first comparator with the input electricity of first pulse counter is connected, the output of first pulse counter with the control module electricity is connected.
5. The touch detection circuit of claim 3, wherein the second detection unit comprises 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;
the one end of third electric capacity with the touch point, the positive pole of third current source, the one end of fourth electric capacity, the one end of fourth switch with the input of second comparator is all connected electrically, the negative pole of third current source with the one end electricity of third switch is connected, the other end of third switch with control module and second power electricity are connected, the other end of fourth switch with control module with the negative pole electricity of fourth current source is connected, the other end of third electric capacity the other end of fourth electric capacity with the positive pole of fourth current source all grounds, the output of second comparator with the input electricity of second pulse counter is connected, the output of second pulse counter with the control module electricity is connected.
6. The touch detection circuit of claim 5, wherein the third detection unit comprises 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 anode of the fifth current source, one end of the sixth switch and the input end of the third comparator, the cathode 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 cathode of the sixth current source, the other end of the fifth capacitor and the anode 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.
7. A detection method applied to the touch detection circuit according to any one of claims 1 to 6, comprising:
outputting a pulse waveform according to the capacitance change of the environment capacitor and the finger touch capacitor and counting the pulse number;
and outputting a high-level touch signal when the pulse number is smaller than a preset value, outputting a low-level touch signal when the pulse number is larger than or equal to the preset value, and updating the preset value at preset intervals according to the change of the pulse waveform output by the environment capacitor.
8. The sensing method of claim 7, wherein outputting a 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 capacitor and the finger touch capacitor and counting a first pulse number;
or outputting a second pulse waveform and counting a second pulse number according to the capacitance change of the environment capacitor and the finger touch capacitor, and outputting a third pulse waveform and counting a third pulse number according to the second pulse waveform.
9. The sensing method of claim 8, wherein outputting a high level touch signal when the number of pulses is less than the preset value and outputting a low level touch signal when the number of pulses is greater than or equal to the preset value comprises:
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 larger than or equal to the preset value;
or outputting a high-level touch signal when the third pulse number is smaller than the preset value, and outputting a low-level touch signal when the third pulse number is larger than or equal to the preset value.
10. The method according to claim 8 or 9, wherein the updating the preset value according to the change of the pulse waveform output by the environment capacitor every preset time interval comprises:
and updating the preset value into the pulse number of the pulse waveform of the low-level touch signal output according to the environment capacitor at preset time intervals.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111322725.9A CN114217705B (en) | 2021-11-09 | Touch detection circuit and detection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111322725.9A CN114217705B (en) | 2021-11-09 | Touch detection circuit and detection method |
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| Publication Number | Publication Date |
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| CN114217705A true CN114217705A (en) | 2022-03-22 |
| CN114217705B CN114217705B (en) | 2024-05-24 |
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