CN110945471A - Common mode noise filtering method, MCU, touch control equipment and storage medium - Google Patents
Common mode noise filtering method, MCU, touch control equipment and storage medium Download PDFInfo
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- 238000012935 Averaging Methods 0.000 description 26
- 238000003825 pressing Methods 0.000 description 11
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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
- G06F3/05—Digital input using the sampling of an analogue quantity at regular intervals of time, input from a/d converter or output to d/a converter
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- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
- H03K17/96—Touch switches
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Abstract
The application provides a common-mode noise filtering method, an MCU, touch equipment and a storage medium. The method comprises the following steps: the method comprises the steps of obtaining the current voltage of a channel at the current moment, and N historical denoising voltages at N moments before the current moment respectively, wherein N is an integer larger than 1. And obtaining the denoising voltage corresponding to the current voltage according to the current voltage and the N historical denoising voltages. Because the data of the wave crests and the wave troughs of the current voltage and the N historical denoising voltages can be mutually offset, the obtained denoising voltage corresponding to the current voltage is more gentle, and the effect of noise suppression is achieved. In addition, the touch sensor does not need to introduce extra capacitance, and therefore extra interference cannot be introduced to the touch sensor.
Description
Technical Field
The present application relates to the field of touch technologies, and in particular, to a common mode noise filtering method, an MCU, a touch device, and a storage medium.
Background
Touch control equipment is frequently used in daily life of people at present, such as a gas stove, a touch control lamp and the like. Among these touch devices are: the touch screen comprises a Micro Control Unit (MCU) and a touch key, wherein a channel exists between the MCU and the touch key, and a touch sensor is arranged below the touch key.
Common mode noise, also known as asymmetric noise or line-to-ground noise, is present at the input of electrical equipment that uses ac power. Therefore, when the touch sensor is charged by the charger, common-mode noise is introduced by ripple interference of a power supply, if the noise is not suppressed, the sensitivity of the touch sensor is affected, and in severe cases, the touch key is mistakenly identified as a finger press, namely, a false key exists.
In the prior art, common-mode noise is filtered by connecting an inductance capacitor in series on the channel, however, the touch sensor has high sensitivity requirement, so that the noise suppression of the filtering method is far insufficient for the touch sensor; furthermore, if a capacitance is added to the channel, the capacitance may even be mutually capacitive with the touch sensor, introducing additional interference to the touch sensor.
Disclosure of Invention
The application provides a common-mode noise filtering method, an MCU, touch equipment and a storage medium. On the basis of the method, on one hand, noise can be effectively suppressed, and on the other hand, extra interference can not be introduced into the touch sensor.
In a first aspect, the present application provides a common mode noise filtering method, which is applied to a micro control unit MCU, the MCU is connected to a touch key through a channel, and a touch sensor is disposed below the touch key, the method including: the method comprises the steps of obtaining the current voltage of a channel at the current moment, and N historical denoising voltages at N moments before the current moment respectively, wherein N is an integer larger than 1. And obtaining the denoising voltage corresponding to the current voltage according to the current voltage and the N historical denoising voltages.
Because the data of the wave crests and the wave troughs of the current voltage and the N historical denoising voltages can be mutually offset, the obtained denoising voltage corresponding to the current voltage is more gentle, and the effect of noise suppression is achieved. In addition, the touch sensor does not need to introduce extra capacitance, and therefore extra interference cannot be introduced to the touch sensor.
Optionally, obtaining the current voltage of the channel at the current time includes: and acquiring the current voltage of the channel at the current moment through an analog-to-digital converter (ADC). And the acquisition frequency of the ADC is greater than the preset frequency.
Based on this, on one hand, the problem of phase lag can be solved, and on the other hand, because the data bulk that the ADC gathered increases, the influence that makes the mean value filter cause action discernment is littleer.
Optionally, obtaining the current voltage of the channel at the current time includes: m voltages of the channel are collected through the ADC within a preset time period, wherein the preset time period is a time period before the current time, or the preset time period comprises the current time, and M is an integer greater than 1. The average of the M voltages is determined to obtain the current voltage. And because the MCU can also average a plurality of voltages to obtain the current voltage, namely filtering the source data. Thereby further improving the filtering effect. In addition, the acquisition frequency of the ADC may be greater than the preset frequency. Based on this, on one hand, the problem of phase lag can be solved, and on the other hand, because the data bulk that the ADC gathered increases, the influence that makes the mean value filter cause action discernment is littleer.
Optionally, the ADC acquisition frequency is proportional to the order N +1 of the averaging filter.
Optionally, obtaining a denoising voltage corresponding to the current voltage according to the current voltage and the N historical denoising voltages includes: and determining the average value of the current voltage and the N historical denoising voltages to obtain the denoising voltage corresponding to the current voltage. The mean value filtering mode can enable the data of wave crests and wave troughs of the current voltage and the data of wave troughs of the N historical denoising voltages to be mutually offset, so that the obtained denoising voltage corresponding to the current voltage is more gentle, and the effect of noise suppression is achieved.
Alternatively, the common mode noise is modeled by white noise emitted by a signal generator.
The MCU, the touch device, the readable storage medium, and the computer program product will be described below, and the effects thereof can refer to the effects of the above methods, which will not be described further below.
In a second aspect, the present application provides an MCU, MCU passes through the passageway and is connected with the touch button, and touch button below is provided with touch sensor, and MCU includes:
the acquisition module is used for acquiring the current voltage of the channel at the current moment and N historical denoising voltages at N moments before the current moment respectively, wherein N is an integer greater than 1.
And the filtering module is used for obtaining the denoising voltage corresponding to the current voltage according to the current voltage and the N historical denoising voltages.
In a third aspect, the present application provides an MCU, where the MCU is connected to a touch key through a channel, a touch sensor is disposed below the touch key, and the MCU is configured to execute the common mode noise filtering method according to the first aspect or the optional manner of the first aspect.
In a fourth aspect, the present application provides a touch device, including: the MCU is connected with the touch key through a channel, a touch sensor is arranged below the touch key, and the MCU is used for executing the common mode noise filtering method according to the first aspect or the optional mode of the first aspect.
In a fifth aspect, the present application provides a readable storage medium comprising program instructions which, when run on a computer, cause the computer to perform the method of common mode noise filtering according to the first aspect or alternatives thereof.
In a sixth aspect, the present application provides a computer program product comprising program instructions for testing the common mode noise filtering method of the first aspect or the alternatives of the first aspect.
The application provides a common-mode noise filtering method, an MCU, touch equipment and a storage medium. The average filtering mode and the average mode of the M square voltages can improve the noise filtering effect, and do not bring extra interference to the touch sensor. And through improving the acquisition frequency of ADC, can solve the problem that the phase place lags on the one hand, on the other hand, because the data bulk that the ADC gathered increases for the influence that the mean value filter caused to action discernment is littleer.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.
FIG. 1 is a schematic diagram of the connection between the MCU and the touch key;
fig. 2 is a flowchart of a common mode noise filtering method according to an embodiment of the present application;
FIG. 3 is a diagram illustrating the filtering effect of an averaging filter in the presence of white noise of 5Vpp without compression according to an embodiment of the present application;
fig. 4 is a graph illustrating the filtering effect of an averaging filter in the presence of white noise of 10Vpp and M ═ 1 in the absence of a press according to an embodiment of the present application;
fig. 5 is a graph illustrating the filtering effect of an averaging filter in the presence of white noise of 10Vpp and M ═ 5 in the absence of a press according to an embodiment of the present application;
FIG. 6 is a graph of the filtering effect in the presence of compression and without white noise at a 50Hz acquisition frequency according to an embodiment of the present application;
FIG. 7 is a graph of the filtering effect in the presence of a press and without white noise at a 100Hz acquisition frequency according to an embodiment of the present application;
FIG. 8 is a graph of the filtering effect provided by an embodiment of the present application in the presence of white noise at 50Hz and without compression;
FIG. 9 is a graph of the filtering effect provided by an embodiment of the present application in the presence of white noise at 100Hz and without compression;
fig. 10 is a graph of the filtering effect provided by an embodiment of the present application in the presence of a press and 5Vpp white noise, 100Hz acquisition frequency, and M equal to 5;
fig. 11 is a graph of the filtering effect provided by an embodiment of the present application in the presence of a press and in the presence of white noise of 10Vpp, a collection frequency of 100Hz, and M equal to 5;
fig. 12 is a schematic diagram of an MCU according to an embodiment of the present application.
Detailed Description
As described above, the current touch device includes: a Micro Control Unit (MCU) and a touch key, wherein a channel exists between the MCU and the touch key. Fig. 1 is a schematic diagram illustrating a connection between an MCU and a touch key, and as shown in fig. 1, a typical touch key currently exists, which includes: the touch keys are also called touch sensing electrodes, for example, keys 0, 1 and 2 in fig. 1 are all key touch keys, the key 3 is a circular touch key, and the key 4 is a slide bar touch key. The slider touch key is formed by 3 touch keys or units, the circular touch key is formed by 4 touch keys or units, and each touch key or unit is connected with the MCU through a channel, for example: the keys 0, 1 and 2 are respectively connected with the MCU through the channels 0, 1 and 2, the key 3 is respectively connected with the MCU through the channels 3, 4, 5 and 6, and the key 4 is respectively connected with the MCU through the channels 7, 8 and 9. It should be noted that the touch key to be mentioned below in this application may be the upper key type touch key, or one of the slide bar type touch keys, or one of the circular type touch keys.
The principle that whether the MCU detects the finger pressing condition on the touch key is as follows: any touch key can be understood as a capacitor, the MCU can obtain a voltage Vout on a channel corresponding to the touch key through an Analog-to-Digital Converter (ADC), where when no finger presses on a touch key, the voltage Vout is generally 2048, where 2048 is a value after normalization processing according to the precision of the ADC, and the Vout is a reference voltage Base of the channel corresponding to the touch key. When a finger presses the touch key, a capacitance is formed between a human body and the ground, and the capacitance is connected with the touch key in series, so that the capacitance of the touch key is increased, and further, the voltage on the touch key is decreased within the same time, for example, the voltage is about Vout 1600. This 1600 is again the value after normalization processing according to the accuracy of the ADC. The MCU determines whether there is a finger pressing the touch key by calculating Delta-Base-Vout, for example: and when the Delta value is more than 200, the touch key is considered to be pressed by the finger.
As described above, when the touch sensor is charged by the charger, common mode noise is introduced by ripple interference of the power supply, and if the noise is not suppressed, the sensitivity of the touch sensor is affected, and in a serious case, the touch key is erroneously recognized as a case where a finger is pressed, that is, a case where a false key is present. In the prior art, common-mode noise is filtered by connecting an inductance capacitor in series on the channel, however, the touch sensor has higher sensitivity requirement, so that the noise suppression of the filtering method is far insufficient for the touch sensor; furthermore, if a capacitance is added to the channel, the capacitance may even be mutually capacitive with the touch sensor, introducing additional interference to the touch sensor.
In order to solve the technical problem, the application provides a common mode noise filtering method, an MCU, a touch device and a storage medium.
The main idea of the application is as follows: and calculating the obtained multiple historical denoising voltages and the current voltage collected by the ADC to obtain the denoising voltage corresponding to the current voltage. By the method, the characteristics of common-mode noise are fully utilized, data of wave crests and wave troughs of a plurality of historical denoising voltages and the data of wave troughs of the current voltage can be mutually offset, so that the obtained denoising voltage corresponding to the current voltage is more gentle, and the effect of noise suppression is achieved.
It should be noted that: the MCU may use the same filtering method for all the voltages collected by the ADC, but is not limited thereto.
The technical scheme of the application is explained in detail as follows:
fig. 2 is a flowchart of a common mode noise filtering method according to an embodiment of the present application, where the method is applied to an MCU, the MCU is connected to a touch key through a channel, and a touch sensor is disposed below the touch key, so that the MCU may be considered to be connected to the touch sensor through the channel, or the MCU may be considered to be connected to the touch sensing electrode through the channel. Based on this, the above method comprises:
step S201: the MCU acquires the current voltage of the channel at the current moment and N historical denoising voltages at N moments before the current moment respectively, wherein N is an integer larger than 1.
Step S202: and the MCU obtains a denoising voltage corresponding to the current voltage according to the current voltage and the N historical denoising voltages.
When the filtering test is performed, a probe of a signal generator can be connected to the channel, and the signal generator is used for generating white noise to simulate common mode noise on the touch sensor, wherein the white noise can be 5 Peak-to-Peak voltage (Vpp) or 10Vpp white noise.
Step S201 is explained as follows:
one alternative is to: the MCU can acquire the current voltage of the channel at the current moment through the ADC.
Another alternative is: the MCU can acquire M voltages of the channel in a preset time period through the ADC and determine the average value of the M voltages to obtain the current voltage, wherein M is an integer larger than 1. The preset time period is a time period before the current time, and the preset time period may be adjacent to the current time or not, which is not limited in the present application, or the preset time period includes the current time, that is, the preset time period is a time period before the current time, and a right end point of the preset time period is the current time. For example: and M is 5, the ADC collects 5 voltages, and the MCU averages the 5 voltages to obtain the current voltage.
It should be noted that the current voltage collected by the ADC is normalizedThe numerical values of (a) such as: when the ADC has an accuracy of 12, then 2124096, 4096 corresponds to a voltage of 3.3V, and when the finger is pressing the touch key, the voltage on the touch key is 2048, which represents 1.65V.
The second optional mode is that the MCU averages the M voltages acquired by the ADC, and because the data of the wave crests and the wave troughs of the M voltages can be mutually offset, the obtained current voltage is more gentle, and the effect of noise suppression is achieved. In addition, in the mode of carrying out multiple acquisition and averaging by the ADC, the M is a fixed value, namely the MCU realizes filtering in a fixed window.
The MCU may average the M voltages by using an arithmetic average algorithm, a geometric average algorithm, or a harmonic average algorithm, so as to obtain the current voltage.
Step S202 is explained as follows:
optionally, the MCU determines the average value of the current voltage and the N historical denoising voltages to obtain a denoising voltage corresponding to the current voltage. The MCU may average the current voltage and the N historical denoising voltages by using an arithmetic average algorithm, a geometric average algorithm, or a harmonic average algorithm, to obtain a denoising voltage corresponding to the current voltage.
For example: the MCU adopts an arithmetic mean algorithm, and calculates the denoising voltage corresponding to the current voltage according to the formula (1):
wherein y (N) is a denoising voltage corresponding to the current voltage, x (N) is the current voltage, y (N-1) is a historical denoising voltage at the previous moment of the current moment, and y (N-N) is a historical denoising voltage at the previous N moments of the current moment. If the denoising voltage corresponding to the current voltage is understood as the process realized by the mean filter, N +1 is the order of the mean filter. It should be noted that the averaging filter is actually implemented by software.
The time may be in units of frames, slots, milliseconds, or the like. For example: y (N) is the denoising voltage corresponding to the current voltage, x (N) is the current voltage, y (N-1) is the historical denoising voltage of the previous frame of the current frame, and y (N-N) is the historical denoising voltage of the previous N frames of the current frame. The unit of time is not limited in this application.
The previous time of the current time may be adjacent to the current time, or may not be adjacent to the current time. The time corresponding to the N historical denoising voltages may be a continuous time or a non-continuous time, which is not limited in this application.
Assuming that a previous time of a current time may be adjacent to the current time, and times corresponding to the N historical denoising voltages are continuous times, that is, the N historical denoising voltages are continuous N historical denoising voltages, and the N historical denoising voltages include: and if the historical denoising voltage is acquired at the latest time from the current moment, the core idea of the mean filter is to continuously perform mean processing on the current voltage and the N historical denoising voltages in a sliding window mode. Because the data of the wave crests and the wave troughs of the current voltage and the N historical denoising voltages can be mutually offset, the obtained denoising voltage corresponding to the current voltage is more gentle, and the effect of noise suppression is achieved.
Fig. 3 is a diagram illustrating the filtering effect of an averaging filter in the presence of white noise of 5Vpp without pressing according to an embodiment of the present application, where as shown in fig. 3, the abscissa represents the voltage acquisition time, the unit of the time may be a frame, and the ordinate represents the voltage, where the voltage is a normalized value, curve 1 represents a curve formed by voltages acquired by an ADC at various times, and curve 2 represents a curve formed by voltages at various times after being filtered by the averaging filter. The order of the average filter is 4, and it can be seen from the curve 2 that the denoising voltage gradually becomes gentle after several times of convergence.
Further, as described above, the present application may also average the M voltages to obtain the current voltage, and filter the noise on the data source. For example: fig. 4 is a graph illustrating the filtering effect of an averaging filter in the presence of white noise of 10Vpp and M ═ 1 without pressing according to an embodiment of the present application, where a curve 1 represents a curve formed by voltages collected by an ADC at various times, and a curve 2 represents a curve formed by voltages at various times after being filtered by the averaging filter. Fig. 5 is a graph illustrating the filtering effect of an averaging filter in the presence of white noise of 10Vpp and M ═ 5 without pressing according to an embodiment of the present application, where a curve 1 represents a curve formed by averaging voltages acquired by an ADC at 5 times, and a curve 2 represents a curve formed by voltages at respective times after being filtered by the averaging filter. As can be seen from fig. 4 and 5, the way in which the current voltage is obtained by averaging every 5 voltages, the noise amplitude is significantly reduced compared to the case where averaging is not performed (i.e., M is 1).
In summary, the present application provides a common mode noise filtering method, including: the MCU acquires the current voltage of the channel at the current moment and N historical denoising voltages at N moments before the current moment respectively. And the MCU obtains a denoising voltage corresponding to the current voltage according to the current voltage and the N historical denoising voltages so as to filter the common-mode noise on the touch sensor. Because the data of the wave crests and the wave troughs of the current voltage and the N historical denoising voltages can be mutually offset, the obtained denoising voltage corresponding to the current voltage is more gentle, and the effect of noise suppression is achieved. Further, the MCU can average M voltages acquired by the ADC, and the acquired current voltage is more gentle due to mutual cancellation of data of wave crests and wave troughs of the M voltages, so that a noise suppression effect is achieved.
It should be noted that, the above-mentioned scheme for obtaining the current voltage by averaging the M voltages acquired by the ADC for the MCU may be decoupled from the above-mentioned average filtering scheme, that is, the above-mentioned average filtering scheme is not required to be combined.
In consideration of the above mentioned average filtering scheme, since the MCU needs to obtain N historical denoising voltages and average the current voltage and the N historical denoising voltages, a certain phase lag may be caused. On the other hand, for an action with a fast pressing speed, since the time for which the finger touches the touch sensor is short, the acquired voltage is filtered out as noise. Therefore, in the present application, the MCU may control the sampling frequency of the ADC to be greater than a preset frequency when performing voltage sampling through the ADC, where the preset frequency may be the sampling frequency of the ADC under normal conditions, such as 50 Hertz (Hertz, Hz), and the sampling frequency of the ADC may be 100 Hz. Optionally, the acquisition frequency is proportional to the order of the averaging filter.
For example: fig. 6 is a diagram of a filtering effect under the condition of having a press and having no white noise and a 50Hz acquisition frequency according to an embodiment of the present application, as shown in fig. 6, an abscissa represents a voltage acquisition time, a unit of the time may be a frame, and an ordinate represents a voltage, where the voltage is a normalized value, and assuming that no white noise is currently added, the voltage distribution of 3 single clicks, 3 double clicks, and 1 long press operation is shown in fig. 6, a curve 1 represents a voltage acquisition value under the condition of not performing filtering, and these three actions can be clearly distinguished from fig. 6. The 4 th order averaging filter has the following effects on the acquired voltage: curve 2 shows the voltage distribution in the case of filtering, and it can be seen from fig. 6 that the double click action is difficult to identify. This is because the double-click action has a fast pressing speed and a short time to contact the touch sensor, resulting in the collected voltage being filtered out as noise.
Fig. 7 is a graph of the filtering effect provided by an embodiment of the present application in the presence of a press and without white noise at a collection frequency of 100Hz, where, as shown in fig. 7, the abscissa represents the voltage acquisition time, which may be in units of frames, and the ordinate represents the voltage, where the voltage is a normalized value. The curve 1 represents the voltage acquisition value under the condition of not performing filtering, and the curve 2 represents the voltage distribution condition under the condition of filtering, so that after the acquisition frequency is increased, the influence of the mean filter on the action recognition is smaller because the data volume acquired by the ADC is increased. As can be seen from fig. 7, a single click and a long press can be fully recognized. Since the pressing width of the double click action is widened and is not easily filtered by the averaging filter, the double click action can be recognized.
It should be noted that, since the power spectrum of the ideal white noise is constant, the interference to the voltages acquired at different acquisition frequencies is the same, and therefore, the filtering effect of the common mode noise is not affected before and after the voltage acquisition frequency is increased. For example: fig. 8 is a graph of a filtering effect provided in an embodiment of the present application under a condition of no pressing and 5Vpp white noise and 50Hz acquisition frequency, where a curve 1 represents a voltage acquisition value under a condition of no filtering, a curve 2 represents a voltage distribution condition under a condition of filtering, fig. 9 is a graph of a filtering effect provided in an embodiment of the present application under a condition of no pressing and 5Vpp white noise and 100Hz acquisition frequency, a curve 1 represents a voltage acquisition value under a condition of no filtering, and a curve 2 represents a voltage distribution condition under a condition of filtering.
Fig. 10 is a graph of the filtering effect provided by an embodiment of the present application in the presence of a press and in the presence of 5Vpp white noise, a 100Hz acquisition frequency, and M equal to 5, where curve 1 represents a curve formed by averaging voltages acquired by an ADC at 5 times, and curve 2 represents a curve formed by averaging voltages at respective times after filtering by an averaging filter. Fig. 11 is a graph of the filtering effect provided by an embodiment of the present application in the presence of a press and white noise of 10Vpp, a 100Hz acquisition frequency, and M equal to 5, where a curve 1 represents a curve formed by averaging voltages acquired by an ADC at 5 times, and a curve 2 represents a curve formed by averaging voltages at respective times after filtering by an averaging filter. As can be seen from fig. 10 and fig. 11, even if white noise of 5Vpp and 10Vpp exists, the following can be clearly identified by the technical solutions provided by the present application, i.e., the solution of mean filtering, increasing the ADC acquisition frequency, and averaging 5 voltages: there are 3 clicks, 3 double clicks, and 1 long press in left-to-right order.
In summary, the present application provides a common mode noise filtering method, based on the average filtering performed by the MCU, the MCU can also increase the voltage acquisition frequency, so that on the one hand, the problem of phase lag can be solved, and on the other hand, the average filter has less influence on the motion recognition due to the increase of the data collected by the ADC. Further, the MCU may also average a plurality of voltages to obtain a current voltage, i.e., filter the source data. Thereby further improving the filtering effect.
Fig. 12 is a schematic diagram of an MCU provided in an embodiment of the present application, where the MCU is connected to a touch key through a channel, and a touch sensor is disposed below the touch key, and the MCU includes:
an obtaining module 1201, configured to obtain a current voltage of a channel at a current time, and N historical denoising voltages at N times before the current time, where N is an integer greater than 1.
And the filtering module 1202 is configured to obtain a denoising voltage corresponding to the current voltage according to the current voltage and the N historical denoising voltages.
Optionally, the obtaining module 1201 is specifically configured to: and acquiring the current voltage of the channel at the current moment through an analog-to-digital converter (ADC). And the acquisition frequency of the ADC is greater than the preset frequency.
Optionally, the obtaining module 1201 is specifically configured to: m voltages of the channel are collected through the ADC within a preset time period, wherein the preset time period is a time period before the current moment, or the preset time period comprises the current moment. The average of the M voltages is determined to obtain the current voltage.
Optionally, the acquisition frequency of the ADC is greater than the preset frequency.
Optionally, the filtering module 1202 is specifically configured to: and determining the average value of the current voltage and the N historical denoising voltages to obtain the denoising voltage corresponding to the current voltage.
Alternatively, the common mode noise is modeled by white noise emitted by a signal generator.
Optionally, the N historical denoising voltages are N continuous historical denoising voltages, and the N historical denoising voltages include: and historical denoising voltage obtained at the latest time from the current moment.
The MCU provided in the present application can execute the above reference voltage updating method, and the content and effect thereof can refer to the embodiment of the method, which is not described herein again.
The present application further provides an MCU, where the MCU is configured to execute the common mode noise filtering method, and the content and effect of the MCU can refer to the method embodiment section, which is not described herein again.
The present application further provides a touch device, exemplarily, the touch device includes: the touch key comprises an MCU and a touch key, wherein the MCU is connected with the touch key through a channel, and exemplarily, as shown in FIG. 1, a typical touch key currently exists and comprises: the touch key comprises a key type touch key, a slide bar type touch key and a circular type touch key, for example, keys 0, 1 and 2 in fig. 1 are all key type touch keys, a key 3 is a circular type touch key, and a key 4 is a slide bar type touch key. The slider touch key is formed by 3 touch keys or units, the circular touch key is formed by 4 touch keys or units, and each touch key or unit is connected with the MCU through a channel, for example: the keys 0, 1 and 2 are respectively connected with the MCU through the channels 0, 1 and 2, the key 3 is respectively connected with the MCU through the channels 3, 4, 5 and 6, and the key 4 is respectively connected with the MCU through the channels 7, 8 and 9. The MCU is configured to execute the common mode noise filtering method, and the content and effect of the common mode noise filtering method can be referred to in the embodiment of the method, which is not described herein again.
The present application further provides a readable storage medium, which includes program instructions, and when the program instructions are executed on a computer, the computer executes the common mode noise filtering method as described above, and the content and effect of the common mode noise filtering method can refer to the embodiment of the method, which is not described herein again.
The present application further provides a computer program product, which includes a program instruction, where the program instruction is used for testing the common mode noise filtering method as described above, and the content and effect of the common mode noise filtering method can be referred to in the embodiment of the method, which is not described herein again.
Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (17)
1. A common mode noise filtering method is characterized in that the common mode noise filtering method is applied to a Micro Control Unit (MCU), the MCU is connected with a touch key through a channel, a touch sensor is arranged below the touch key, and the common mode noise filtering method comprises the following steps:
acquiring the current voltage of the channel at the current moment and N historical denoising voltages at N moments before the current moment respectively, wherein N is an integer greater than 1;
and obtaining the denoising voltage corresponding to the current voltage according to the current voltage and the N historical denoising voltages.
2. The method of claim 1, wherein the obtaining a current voltage of the channel at a current time comprises:
acquiring the current voltage of the channel at the current moment through an analog-to-digital converter (ADC);
and the acquisition frequency of the ADC is greater than the preset frequency.
3. The method of claim 1, wherein the obtaining a current voltage of the channel at a current time comprises:
acquiring M voltages of the channel in a preset time period through an analog-to-digital converter (ADC), wherein the preset time period is a time period before the current moment, or the preset time period comprises the current moment, and M is an integer greater than 1;
and determining the average value of the M voltages to obtain the current voltage.
4. The method of claim 3, wherein the ADC has a sampling frequency greater than a predetermined frequency.
5. The method according to any one of claims 1-4, wherein obtaining the de-noising voltage corresponding to the current voltage according to the current voltage and the N historical de-noising voltages comprises:
and determining the average value of the current voltage and the N historical denoising voltages to obtain a denoising voltage corresponding to the current voltage.
6. The method according to any of claims 1-4, wherein the common mode noise is modeled by white noise emitted by a signal generator.
7. The method according to any one of claims 1-4, wherein the N historical denoising voltages are N consecutive historical denoising voltages, and the N historical denoising voltages comprise: and obtaining the historical denoising voltage which is obtained at the latest time from the current moment.
8. The utility model provides a MCU, its characterized in that, MCU passes through the passageway and is connected with the touch button, touch button below is provided with touch sensor, MCU includes:
the acquisition module is used for acquiring the current voltage of the channel at the current moment and N historical denoising voltages at N moments before the current moment respectively, wherein N is an integer greater than 1;
and the filtering module is used for obtaining the denoising voltage corresponding to the current voltage according to the current voltage and the N historical denoising voltages.
9. The MCU of claim 8, wherein the acquisition module is specifically configured to:
acquiring the current voltage of the channel at the current moment through an analog-to-digital converter (ADC);
and the acquisition frequency of the ADC is greater than the preset frequency.
10. The MCU of claim 8, wherein the acquisition module is specifically configured to:
acquiring M voltages of the channel in a preset time period through an analog-to-digital converter (ADC), wherein the preset time period is a time period before the current moment, or the preset time period comprises the current moment, and M is an integer greater than 1;
and determining the average value of the M voltages to obtain the current voltage.
11. The MCU of claim 10, wherein the acquisition frequency of the ADC is greater than a preset frequency.
12. An MCU according to any of claims 8-11, wherein the filtering module is specifically configured to:
and determining the average value of the current voltage and the N historical denoising voltages to obtain a denoising voltage corresponding to the current voltage.
13. An MCU according to any of claims 8-11, wherein the common mode noise is modelled by white noise emitted by the signal generator.
14. The MCU of any one of claims 8-11, wherein the N historical denoising voltages are N consecutive historical denoising voltages, and the N historical denoising voltages comprise: and obtaining the historical denoising voltage which is obtained at the latest time from the current moment.
15. An MCU, wherein the MCU is connected with a touch key through a channel, a touch sensor is arranged below the touch key, and the MCU is used for executing the common mode noise filtering method according to any one of claims 1 to 7.
16. A touch device, comprising: the MCU is connected with the touch key through a channel, a touch sensor is arranged below the touch key, and the MCU is used for executing the common mode noise filtering method according to any one of claims 1 to 7.
17. A readable storage medium characterized by comprising program instructions which, when run on a computer, cause the computer to perform the common mode noise filtering method according to any one of claims 1 to 7.
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| PCT/CN2019/114409 WO2021081821A1 (en) | 2019-10-30 | 2019-10-30 | Common-mode noise filtering method, mcu, touch device, and storage medium |
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| WO1998002964A1 (en) * | 1996-07-12 | 1998-01-22 | Synaptics, Incorporated | Object position detector with noise suppression feature |
| US5889236A (en) * | 1992-06-08 | 1999-03-30 | Synaptics Incorporated | Pressure sensitive scrollbar feature |
| US20160274730A1 (en) * | 2015-03-16 | 2016-09-22 | Parade Technologies Ltd. | Differential IIR Baseline Algorithm for Capacitive Touch Sensing |
| CN109039320A (en) * | 2018-08-15 | 2018-12-18 | 深圳市麦道微电子技术有限公司 | A kind of highly reliable capacitance type touch key can satisfy complex working condition |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3432128B1 (en) * | 2017-02-16 | 2023-08-02 | Shenzhen Goodix Technology Co., Ltd. | Button detection method and device |
| CN109582176B (en) * | 2018-11-30 | 2021-12-24 | 北京集创北方科技股份有限公司 | Anti-noise method and device for touch screen |
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2019
- 2019-10-30 WO PCT/CN2019/114409 patent/WO2021081821A1/en active Application Filing
- 2019-10-30 CN CN201980002382.2A patent/CN110945471A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5889236A (en) * | 1992-06-08 | 1999-03-30 | Synaptics Incorporated | Pressure sensitive scrollbar feature |
| WO1998002964A1 (en) * | 1996-07-12 | 1998-01-22 | Synaptics, Incorporated | Object position detector with noise suppression feature |
| CN1197555A (en) * | 1996-07-12 | 1998-10-28 | 辛纳普蒂克斯有限公司 | Object position detector with noise suppression feature |
| US20160274730A1 (en) * | 2015-03-16 | 2016-09-22 | Parade Technologies Ltd. | Differential IIR Baseline Algorithm for Capacitive Touch Sensing |
| CN109039320A (en) * | 2018-08-15 | 2018-12-18 | 深圳市麦道微电子技术有限公司 | A kind of highly reliable capacitance type touch key can satisfy complex working condition |
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