CN219834117U - Anti-interference circuit, touch equipment and intelligent door lock of touch button - Google Patents

Abstract

The utility model relates to the technical field of touch equipment, in particular to an anti-interference circuit of a touch key, the touch equipment and an intelligent door lock, wherein the circuit comprises: a plurality of key pads, a plurality of touch channels and a touch chip; one end of the touch channel is connected with one key pad, and the other end of the touch channel is connected with one touch pin of the touch chip; the touch channels are in one-to-one correspondence with the key pads, and detection pins of the detection circuit of the touch chip are grounded through the filter capacitor. The circuit uses the pin channel of one touch chip to be connected with a filter capacitor to be used as a common filter channel of all touch channels, thus the complexity of the touch key circuit can be greatly reduced, the design of the circuit board of the touch key is simple, the anti-interference capability of the touch key is improved, and the cost is reduced.

Description

Anti-interference circuit, touch equipment and intelligent door lock of touch button

Technical Field

The utility model relates to the technical field of touch equipment, in particular to an anti-interference circuit of a touch key, the touch equipment and an intelligent door lock.

Background

At present, the capacitive touch key is widely applied to electronic products such as electromagnetic ovens, microwave ovens, soymilk machines, wall breaking machines, coffee machines, smoke exhaust ventilators, water dispensers, intelligent door locks, intelligent bathrooms, intelligent lamp control and the like. The capacitive touch key mainly uses a sensing spring as a touch sensor, a sensing channel of a touch chip of the capacitive touch key is connected to a corresponding sensing spring pin through a wiring on a PCB, and the sensing spring is directly propped against a position of a corresponding functional area of the touch panel to form the capacitive touch key. Various function keys to be realized are silk-screened on the touch panel, and one function key corresponds to one sensing spring or sensing disc.

For detection of a capacitive touch key, the capacitive touch key is generally composed of a self-capacitive touch chip and a sensor, the sensor can use copper foil on a PCB to design corresponding patterns, the patterns are connected to a capacitive detection channel of the touch chip, and the touch chip judges whether a finger is pressed or not through detection of a grounding capacitor on an induction channel. The self-capacitance touch mode has low cost and high detection sensitivity, but is sensitive to power supply fluctuation, in particular common mode interference. In order to reduce interference, a grounded filter capacitor is generally added to the connection line between each sensing channel and the sensor for filtering the power interference signal.

The method of adding a grounded filter capacitor in the sensing channel of each key can improve the power supply interference resistance of the capacitive touch key; but the number of the keys of the household appliances is different from several to twenty. If the number of the keys is large, the sensing channel of each key is connected with a grounding capacitor in parallel, so that the design of the circuit board is complex, and the cost is high. Therefore, a new circuit design of the touch key is needed, so that the problem of power supply interference can be solved, and the design difficulty and cost of the PCB can be reduced.

Disclosure of Invention

The embodiment of the utility model can at least solve the technical problems by providing the anti-interference circuit of the touch key, the touch equipment and the intelligent door lock.

In a first aspect, an embodiment of the present utility model provides an anti-interference circuit for a touch key, including: a plurality of key pads, a plurality of touch channels and a touch chip;

one end of the touch channel is connected with one key pad, and the other end of the touch channel is connected with one touch pin of the touch chip; the touch channels are in one-to-one correspondence with the key pads, and detection pins of the detection circuit of the touch chip are grounded through the filter capacitor.

Preferably, the detection circuit of the touch chip includes: the device comprises an analog-to-digital conversion module, an operational amplifier module and m switches, wherein m is a positive integer not less than 3;

the detection pin is connected with the input end of the operational amplifier through a first switch in the m switches;

for a plurality of key pads, the key pads are connected with the input end of the operational amplifier through one second switch except the first switch in the m switches, and the key pads are connected on a line between the detection pin and the first switch through one third switch except the first switch and the second switch in the m switches;

the output end of the operational amplifier is connected with the input end of the analog-to-digital conversion module.

Preferably, the method further comprises: a capacitor C1;

and an analog voltage pin of the touch chip is grounded through the capacitor C1.

Preferably, the method further comprises: a capacitor C2;

the digital voltage pin of the touch chip is grounded through the capacitor C2.

Preferably, the touch chip further includes: an interrupt pin and a reset pin;

the interrupt pin of the touch chip is connected with the interrupt pin of the main control chip of the touch equipment;

and the reset pin of the touch chip is connected with the reset pin of the main control chip of the touch equipment.

Preferably, the touch chip further includes: a data line pin and a clock line pin;

the data line pin of the touch chip is connected with the data line pin of the main control chip of the touch device;

and the clock line pin of the touch chip is connected with the clock line pin of the main control chip of the touch device.

Preferably, the touch device includes: electromagnetic oven, microwave oven, intelligent door lock, intelligent bathroom and broken wall machine.

Preferably, the touch chip comprises: BMT6320SP or BMT6328SP.

Based on the same inventive concept, the present utility model also provides a touch device, including: the anti-interference circuit and the main control chip of the touch key are as described above;

the interrupt pin of the main control chip is connected with the interrupt pin of the touch chip of the anti-interference circuit of the touch key;

the data line pin of the main control chip is connected with the data line pin of the touch chip of the anti-interference circuit of the touch key;

the clock line pin of the main control chip is connected with the clock line pin of the touch chip of the anti-interference circuit of the touch key;

and the reset pin of the main control chip is connected with the reset pin of the touch chip of the anti-interference circuit of the touch key.

Based on the same inventive concept, in a third aspect, the present utility model further provides an intelligent door lock, comprising: the anti-interference circuit, the main control chip and the lock core of the touch key according to any one of claims 1 to 7;

the interrupt pin of the main control chip is connected with the interrupt pin of the touch chip of the anti-interference circuit of the touch key;

the data line pin of the main control chip is connected with the data line pin of the touch chip of the anti-interference circuit of the touch key;

the clock line pin of the main control chip is connected with the clock line pin of the touch chip of the anti-interference circuit of the touch key;

the reset pin of the main control chip is connected with the reset pin of the touch chip of the anti-interference circuit of the touch key;

and a control pin of the main control chip is connected with the lock cylinder.

One or more technical solutions in the embodiments of the present utility model at least have the following technical effects or advantages:

the utility model provides an anti-interference circuit of a touch key, which comprises: a plurality of key pads, a plurality of touch channels, and a touch chip. One end of the touch channel is connected with one key pad, and the other end of the touch channel is connected with one touch pin of the touch chip; the touch channels are in one-to-one correspondence with the key pads, and detection pins of the detection circuit of the touch chip are grounded through the filter capacitor. The circuit structure uses the pin channel of one touch chip to be connected with a filter capacitor to be used as a common filter channel of all touch channels, and a traditional method that each key channel is connected with one capacitor in parallel to the ground to eliminate power supply interference is changed, so that the complexity of a touch key circuit is greatly reduced, the design of a circuit board of the touch key is simple and concise, the anti-interference capability of the touch key is improved, the cost is reduced, and the like.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the utility model. Also throughout the drawings, like reference numerals are used to designate like parts. In the drawings:

FIG. 1 is a schematic diagram of an anti-interference circuit of a touch key according to an embodiment of the present utility model;

FIG. 2 is a schematic circuit diagram of an anti-interference circuit of a touch key in an embodiment of the utility model;

FIG. 3 shows a schematic circuit diagram of a detection circuit of a touch chip in an embodiment of the utility model;

fig. 4 is a schematic circuit diagram of a detection circuit in an embodiment of the present utility model after only combining the S2 pin channel and the key pad K1 channel;

fig. 5 shows a schematic structural diagram of a touch device in an embodiment of the present utility model;

fig. 6 shows a schematic structural diagram of an intelligent door lock in an embodiment of the present utility model.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

Example 1

A first embodiment of the present utility model provides an anti-interference circuit for a touch key, as shown in FIG. 1 and FIG. 2, including: a plurality of key pads 103, a plurality of touch channels 102, and a touch chip 101. One end of the touch channel is connected with one key pad, and the other end of the touch channel is connected with one touch pin of the touch chip; the touch channels are in one-to-one correspondence with the key pads, and detection pins of the detection circuit of the touch chip are grounded through the filter capacitor.

The key pad is a key sensing disc and is used for sensing whether a key is pressed down or not. The touch channel is a channel wiring connected between the key pad and the touch chip and used for transmitting key signals. The touch chip is used for detecting whether a certain key is pressed according to the key signal transmitted through the touch channel. The detection circuit of the touch chip is used for detecting the key, and the detection pin of the detection circuit is essentially one entity pin of the touch chip, and the entity pin is defined as a detection pin.

In fig. 1, the structure of the anti-interference circuit of the touch key shown in fig. 1 includes 4 key pads, 4 touch channels and one touch chip. Each key pad is connected to the touch chip through a touch channel, and a detection pin of a detection circuit of the touch chip is grounded through a filter capacitor C3.

In fig. 2, the anti-interference circuit of the touch key shown in fig. 2 includes 4 key pads, 4 touch channels and one touch chip, corresponding to the structure of fig. 1. The 4 key pads are denoted as K1, K2, K3 and K4, respectively, each of which is connected to the touch chip via a touch channel. The detection pin of the detection circuit of the touch chip is grounded through the filter capacitor C3, the detection pin is the S2 pin of the touch chip, the S2 pin is connected with one end of the filter capacitor C3, and the other end of the filter capacitor C3 is grounded.

Therefore, the anti-interference circuit of the touch key in the embodiment uses a pin channel and a filter capacitor on the touch chip to serve as a common filter channel of all the touch channels, and a traditional method that each key channel is connected with a capacitor in parallel to the ground is changed to eliminate power supply interference, so that the complexity of the touch key circuit is greatly reduced, the design of a circuit board of the touch key is simple and concise, the anti-interference capability of the touch key is improved, and the cost is reduced.

The anti-interference circuit of touch button still includes: a capacitor C1 and a capacitor C2. And an analog voltage pin of the touch chip is grounded through the capacitor C1. The digital voltage pin of the touch chip is grounded through the capacitor C2.

The touch chip further includes: interrupt pin INT, data line pin SDA, clock line pin SCL, and reset pin RST. And the interrupt pin of the touch chip is connected with the interrupt pin of the main control chip of the touch equipment. And the data line pins of the touch chip are connected with the data line pins of the main control chip of the touch device. And the clock line pin of the touch chip is connected with the clock line pin of the main control chip of the touch device. And the reset pin of the touch chip is connected with the reset pin of the main control chip of the touch equipment.

It should be noted that, the touch device is a device having a touch key function, and the main control chip of the touch device is configured to control the touch device to execute a corresponding specific function according to a signal of the touch key. Taking a touch control device as an example of the water dispenser, a hot water outlet key and a cold water outlet key are arranged on a touch key panel of the water dispenser, and after the water dispenser detects that the hot water outlet key is pressed, a hot water outlet of the water dispenser is controlled to be opened to discharge hot water. And similarly, after the water dispenser detects that the cold water outlet key is pressed, controlling the cold water outlet of the water dispenser to be opened to discharge cold water. Touch devices include, but are not limited to: electromagnetic oven, microwave oven, intelligent door lock, intelligent bathroom, broken wall machine, soybean milk machine and water dispenser.

The detection circuit of the touch chip comprises: the analog-to-digital conversion module, the operational amplifier module and m switches, wherein m is a positive integer not less than 3. The detection pin is connected with the input end of the operational amplifier through a first switch in the m switches. For a plurality of key pads, the key pad is connected with the input end of the operational amplifier through one second switch except the first switch in the m switches, and the key pad is connected on a line between the detection pin and the first switch through one third switch except the first switch and the second switch in the m switches. The output end of the operational amplifier is connected with the input end of the analog-to-digital conversion module. The output end of the analog-to-digital conversion module is connected with an MCU (Micro ControllerUnit, micro control unit) module in the touch chip.

Specifically, as shown in fig. 3, the detection circuit of the touch chip is shown in the dashed box. The detection circuit analog-to-digital conversion module (abbreviated as 'analog-to-digital conversion' in fig. 3), the operational amplifier module (abbreviated as 'operational amplifier' in fig. 3) and m switches. The m switches are divided into switch SW1, switch SW2, switch SW3, switch SW 4. Assuming that there are N keypads (which may also be N touch channels), the N keypads are the maximum of K1, K2, & gt, kn, N, respectively. S2 is a detection pin of the detection circuit in fig. 2, that is, an S2 pin of the touch chip, and is also a pin grounded through the filter capacitor C3.

S2 is connected with the input end of the operational amplifier through SW 1. K1 is connected to the line between S2 and SW1 through SW2, and K1 is connected to the input of the operational amplifier through SW (N+2). K2 is connected to the line between S2 and SW1 through SW3, and K2 is connected to the input of the operational amplifier through SW (N+3). By analogy, kn is connected to the line between S2 and SW1 through swn+1, and Kn is connected to the input of the operational amplifier through SW (n+n+1). Therefore, each key pad can be combined with the filter capacitor C3, the pin channel connected with the filter capacitor to the ground is a common capacitor filter channel of each key pad, the circuit is simplified, the complexity of the circuit design is reduced, the cost is saved, the change quantity generated by the action of each key pad and fingers is conveniently and efficiently detected, and the anti-interference capability of the touch key is provided.

The principle of the detection circuit of the embodiment is that the following steps are completed in a detection scanning period of one touch key:

1) SW1, SW2 and SWn+2 are all in a closed state, and other switches are all in an open state, and simultaneously the capacitance to ground of the two channels of the capacitance receiving channel S2 and the key pad K1 are scanned and detected, so that the key pad K1 is detected.

2) SW1, SW3 and SWn+3 are all in a closed state, and other switches are all in an open state, and simultaneously the capacitance to ground values of the two channels of the capacitance receiving channel S2 and the key pad K2 are scanned and detected, so that the key pad K2 is detected.

3) Similarly, SW1, swn+1 and SW (n+n+1) are all in a closed state, and other switches are all in an open state, and simultaneously the capacitance to ground values of the two channels of the capacitance receiving channel S2 and the key pad Kn are scanned and detected, so that the key pad Kn is detected.

As shown in fig. 4, in the process of detecting only the key pad K1 by the detection circuit, that is, in the process that SW1, SW2 and swn+2 are all in the closed state, other switches are all in the open state, and simultaneously, in the process of scanning and detecting the capacitance to ground values of the two channels of the capacitance-connecting channel S2 and the key pad K1, the total capacitance after the channels are combined is Cs, the ground capacitance of the detection pin S2 is C3, and the finger sensing capacitance of the K1 is Cp. Finally, cs=cp// C3.

The method of scanning keys one by a detection circuit comprises the steps of combining a key channel to be detected with a filter capacitor channel in a touch chip by using a switch, then performing key detection, and switching off the switch of the key after the scanning is completed until all key detection is completed. Therefore, the power supply filtering function of all touch channels can be completed by using one common filtering capacitor, the purposes of simplifying and simplifying the design of a circuit board, reducing the cost, improving the anti-noise interference capability and the like are achieved, and the effect is particularly remarkable under the condition of a large number of keys.

The touch chip comprises the following components: BMT6320SP or BMT6328SP. The type of the touch chip can also be set according to actual requirements.

One or more technical solutions in the embodiments of the present utility model at least have the following technical effects or advantages:

the utility model provides an anti-interference circuit of a touch key, which comprises: a plurality of key pads, a plurality of touch channels, and a touch chip. One end of the touch channel is connected with one key pad, and the other end of the touch channel is connected with one touch pin of the touch chip; the touch channels are in one-to-one correspondence with the key pads, and detection pins of the detection circuit of the touch chip are grounded through the filter capacitor. The circuit structure uses the pin channel of one touch chip to be connected with a filter capacitor to be used as a common filter channel of all touch channels, and a traditional method that each key channel is connected with one capacitor in parallel to the ground to eliminate power supply interference is changed, so that the complexity of a touch key circuit is greatly reduced, the design of a circuit board of the touch key is simple and concise, the anti-interference capability of the touch key is improved, the cost is reduced, and the like.

Example two

Based on the same inventive concept, a second embodiment of the present utility model further provides a touch device, as shown in fig. 5, including: the anti-interference circuit and the main control chip of the touch key according to the first embodiment;

the interrupt pin of the main control chip is connected with the interrupt pin of the touch chip of the anti-interference circuit of the touch key;

the data line pin of the main control chip is connected with the data line pin of the touch chip of the anti-interference circuit of the touch key;

the clock line pin of the main control chip is connected with the clock line pin of the touch chip of the anti-interference circuit of the touch key;

and the reset pin of the main control chip is connected with the reset pin of the touch chip of the anti-interference circuit of the touch key.

Example III

Based on the same inventive concept, a second embodiment of the present utility model further provides a touch device, as shown in fig. 6, including: the anti-interference circuit and the main control chip of the touch key according to the first embodiment;

the interrupt pin of the main control chip is connected with the interrupt pin of the touch chip of the anti-interference circuit of the touch key;

the data line pin of the main control chip is connected with the data line pin of the touch chip of the anti-interference circuit of the touch key;

the clock line pin of the main control chip is connected with the clock line pin of the touch chip of the anti-interference circuit of the touch key;

the reset pin of the main control chip is connected with the reset pin of the touch chip of the anti-interference circuit of the touch key;

and a control pin of the main control chip is connected with the lock cylinder.

The main control chip is used for controlling the lock core to be in a closed state or an open state according to a key signal of the anti-interference circuit of the touch key.

It will be apparent to those skilled in the art that while preferred embodiments of the present utility model have been described, additional variations and modifications may be made to these embodiments once the basic inventive concepts are known to those skilled in the art. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the utility model.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present utility model without departing from the spirit or scope of the utility model. Thus, it is intended that the present utility model also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims (10)

1. An anti-interference circuit for a touch key, comprising: a plurality of key pads, a plurality of touch channels and a touch chip;

one end of the touch channel is connected with one key pad, and the other end of the touch channel is connected with one touch pin of the touch chip; the touch channels are in one-to-one correspondence with the key pads, and detection pins of the detection circuit of the touch chip are grounded through the filter capacitor.

2. The tamper resistant circuit of a touch key of claim 1, wherein the detection circuit of the touch chip comprises: the device comprises an analog-to-digital conversion module, an operational amplifier module and m switches, wherein m is a positive integer not less than 3;

the detection pin is connected with the input end of the operational amplifier through a first switch in the m switches;

for a plurality of key pads, the key pads are connected with the input end of the operational amplifier through one second switch except the first switch in the m switches, and the key pads are connected on a line between the detection pin and the first switch through one third switch except the first switch and the second switch in the m switches;

the output end of the operational amplifier is connected with the input end of the analog-to-digital conversion module.

3. The tamper resistant circuit of a touch key of claim 1, further comprising: a capacitor C1;

and an analog voltage pin of the touch chip is grounded through the capacitor C1.

4. The tamper resistant circuit of a touch key of claim 1, further comprising: a capacitor C2;

the digital voltage pin of the touch chip is grounded through the capacitor C2.

5. The tamper resistant circuit of a touch key of claim 1, wherein the touch chip further comprises: an interrupt pin and a reset pin;

the interrupt pin of the touch chip is connected with the interrupt pin of the main control chip of the touch equipment;

and the reset pin of the touch chip is connected with the reset pin of the main control chip of the touch equipment.

6. The tamper resistant circuit of a touch key of claim 5, wherein the touch chip further comprises: a data line pin and a clock line pin;

the data line pin of the touch chip is connected with the data line pin of the main control chip of the touch device;

and the clock line pin of the touch chip is connected with the clock line pin of the main control chip of the touch device.

7. The tamper resistant circuit of a touch key of claim 6, wherein the touch device comprises: electromagnetic oven, microwave oven, intelligent door lock, intelligent bathroom and broken wall machine.

8. The tamper resistant circuit of a touch key of claim 1, wherein the touch chip model comprises: BMT6320SP or BMT6328SP.

9. A touch device, comprising: the anti-interference circuit and the main control chip of the touch key according to any one of claims 1 to 7;

the interrupt pin of the main control chip is connected with the interrupt pin of the touch chip of the anti-interference circuit of the touch key;

the data line pin of the main control chip is connected with the data line pin of the touch chip of the anti-interference circuit of the touch key;

the clock line pin of the main control chip is connected with the clock line pin of the touch chip of the anti-interference circuit of the touch key;

and the reset pin of the main control chip is connected with the reset pin of the touch chip of the anti-interference circuit of the touch key.

10. An intelligent door lock, characterized by comprising: the anti-interference circuit, the main control chip and the lock core of the touch key according to any one of claims 1 to 7;

the interrupt pin of the main control chip is connected with the interrupt pin of the touch chip of the anti-interference circuit of the touch key;

the data line pin of the main control chip is connected with the data line pin of the touch chip of the anti-interference circuit of the touch key;

the clock line pin of the main control chip is connected with the clock line pin of the touch chip of the anti-interference circuit of the touch key;

the reset pin of the main control chip is connected with the reset pin of the touch chip of the anti-interference circuit of the touch key;

and a control pin of the main control chip is connected with the lock cylinder.