Intelligent door lock touch sensing circuit and intelligent door lock

Abstract

The application discloses a kind of intelligent door lock touch sensing circuit, including PCB board and touch metal plate, one side of PCB board is coated with multiple resistors, the multiple resistors are coated using organic carbon film resistor material, MCU and a connector are further provided on the PCB board, two electrode ends of each resistor are respectively connected with the corresponding pin of MCU, the MCU is also connected with the connector, and the connector is used to be connected with the main control of the intelligent door lock;Touch metal plate is arranged on the side of the PCB board coated with multiple resistors, a plurality of touch key icons corresponding to the multiple resistors are provided on the touch metal plate, for user touch input;When any touch key icon occurs touch operation, the resistance value of the resistor corresponding to the touch key icon changes, the MCU detects the resistance value change amount of the resistor corresponding to the touch key icon, and when the resistance value change amount is greater than a preset threshold, it is judged that key input occurs.

Description

Technical Field

[0001] This invention relates to the field of printed electronics technology, specifically to a smart door lock touch sensing circuit and a smart door lock. Background Technology

[0002] In the smart lock industry, traditional human-machine password input methods include mechanical buttons and capacitive touch-sensitive buttons. Mechanical buttons are mainly used by overseas customers who prefer the tactile feel of mechanical input. However, waterproofing requires silicone insulation, increasing material costs. Furthermore, both silicone and mechanical switches have limited lifespans; silicone and surface adhesives are easily exposed to wind and sun, causing components to age and fade, affecting the user experience.

[0003] Capacitive touch-sensitive buttons serve as a human-computer interaction input interface, utilizing the capacitance value of the human body for input detection. However, capacitive sensing input has a weakness: it cannot transmit data over a metal layer. If there is metal on the top layer of the sensing pads, the capacitive sensor loses its function. Another weakness is that capacitive sensing input is generally not waterproof. When rainwater splashes onto the button surface, it can cause false triggering, mistaking the touchscreen for human input, resulting in a poor user experience in waterproof environments. Summary of the Invention

[0004] Based on the above situation, the main objective of this invention is to provide a smart door lock touch sensing circuit that enables the metal panel to be used for human-computer interaction input, effectively waterproofing, preventing button aging, and effectively extending the button's service life.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A smart door lock touch sensing circuit includes a PCB board and a touch metal plate. One side of the PCB board is coated with multiple resistors, which are made of organic carbon film resistive material. The PCB board also houses an MCU and a connector. The two terminals of each resistor are connected to corresponding pins of the MCU. The MCU is also connected to the connector, which is used to connect to the main controller of the smart door lock. The touch metal plate is located on the side of the PCB board coated with the multiple resistors. The touch metal plate has multiple touch button icons, each corresponding to one of the resistors, for user touch input. When any of the touch button icons is touched, the resistance value of the corresponding resistor changes. The MCU detects the amount of resistance change; when the resistance change exceeds a preset threshold, it determines that a button input has occurred.

[0006] Preferably, the PCB board has pre-reserved coating positions for the plurality of resistors, and the organic carbon film resistor material is then coated at those positions.

[0007] Preferably, the on-resistance of each resistor is 1 megohm.

[0008] Preferably, the preset threshold for the resistance change is 100KΩ.

[0009] Preferably, the organic carbon film resistor material is obtained by depositing gaseous methane and / or ethane through high-temperature vacuum thermal decomposition.

[0010] Preferably, the PCB board is coated with 13 resistors, wherein the first end of resistor 1 is connected to the first pin of the MCU, the first end of resistor 2 is connected to the second pin of the MCU, the first end of resistor 3 is connected to the third pin of the MCU, the first end of resistor 4 is connected to the fourth pin of the MCU, and the second ends of resistors 1, 2, 3, and 4 are collectively connected to the fourteenth pin of the MCU; the second end of resistor 5 is connected to the fifth pin of the MCU, the second end of resistor 6 is connected to the sixth pin of the MCU, the second end of resistor 7 is connected to the seventh pin of the MCU, and the second end of resistor 8 is connected to the fourth pin of the MCU. Two ends of resistor 13 are connected to the eighth pin of the MCU, and the second end of resistor 14 is connected to the thirteenth pin of the MCU. The first ends of resistors 5, 6, 7, 8 and 13 are connected to the fifteenth pin of the MCU. The second end of resistor 9 is connected to the ninth pin of the MCU, the second end of resistor 10 is connected to the tenth pin of the MCU, the second end of resistor 11 is connected to the eleventh pin of the MCU, and the second end of resistor 12 is connected to the twelfth pin of the MCU. The first ends of resistors 9, 10, 11 and 12 are connected to the sixteenth pin of the MCU.

[0011] Preferably, the I2C communication pin of the MCU is connected to the connector, and the MCU communicates with the main controller of the smart door lock using the I2C communication method.

[0012] Preferably, the thickness of the touch metal plate is 1.2mm to 1.5mm.

[0013] Preferably, the top layer of the touch metal plate is laser-engraved to form the touch button icon.

[0014] The present invention also discloses a smart door lock, wherein the smart door lock adopts the smart door lock touch sensing circuit described in any one of the present invention to realize the acquisition of user touch input signals.

[0015] The smart door lock touch sensing circuit of this invention uses organic carbon film resistive material. When a touch occurs, the resistance formed by the organic carbon film resistive material changes, resulting in a change in resistance value, which is then used for signal acquisition, avoiding the capacitive sensing effect. Simultaneously, it enables sensitive human-computer interaction input even on metal panels, effectively preventing accidental triggering and incorrect input of interactive information—a function that conventional capacitive touch sensing chips cannot achieve.

[0016] Other beneficial effects of the present invention will be explained in detail through the introduction of specific technical features and technical solutions in specific embodiments. Those skilled in the art should be able to understand the beneficial technical effects brought about by these technical features and technical solutions through the introduction of these technical features and technical solutions. Attached Figure Description

[0017] The preferred embodiment of the smart door lock touch sensing circuit according to the present invention will now be described with reference to the accompanying drawings. In the drawings: Figure 1 This is a structural diagram of a smart door lock touch sensing circuit according to a preferred embodiment of the present invention; Figure 2 This is a circuit schematic diagram of multiple resistors, an MCU, and connectors connected on a PCB board according to a preferred embodiment of the present invention. Figure 3 This is a physical image of a smart door lock according to a preferred embodiment of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0020] In the description of this invention, unless otherwise explicitly defined, terms such as "setup" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0021] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0022] Figure 1 The present invention provides a preferred embodiment of a smart door lock touch sensing circuit. The smart door lock touch sensing circuit includes a PCB board 100 and a touch metal plate 200. One side of the PCB board 100 is coated with multiple resistors 300, which are made of organic carbon film resistive material. The PCB board 100 also has an MCU (not shown in the figure) and a connector 400. The two terminals of each resistor 300 are respectively connected to the corresponding pins of the MCU. The MCU is also connected to the connector 400, which is used to connect to the main controller of the smart door lock. The touch metal plate 200 is disposed on the side of the PCB board 100 coated with multiple resistors. The touch metal plate 200 has multiple touch button icons corresponding one-to-one with the multiple resistors 300, for user touch input. When any touch button icon is touched, the resistance value of the resistor corresponding to the touch button icon changes. The MCU detects the amount of resistance change, and when the resistance change is greater than a preset threshold, it determines that a button input has occurred.

[0023] The smart door lock touch sensing circuit of this invention uses organic carbon film resistive material. When a touch occurs, the resistance formed by the organic carbon film resistive material changes, resulting in a change in resistance value, which is then used for signal acquisition, avoiding the capacitive sensing effect. Simultaneously, it enables sensitive human-computer interaction input even on metal panels, effectively preventing accidental triggering and incorrect input of interactive information—a function that conventional capacitive touch sensing chips cannot achieve.

[0024] In a preferred embodiment, the PCB board 100 can be pre-designed with its external dimensions according to the product structure assembly requirements, and the pad positions for the sorbet carbon film resistors can be reserved. Then, organic carbon film resistor material is coated on the positions to form the finished PCBA.

[0025] In a specific implementation, a qualified product typically has a conduction resistance of 1 megohm and an error rate of 1%. The conduction resistance in this invention refers to the resistance value of the resistor when it is energized and no contact operation occurs.

[0026] In a preferred embodiment, the preset threshold for the resistance change can be 100KΩ. The resistance is 1 megohm under no pressure; it decreases as pressure increases. When the resistance change exceeds 100KΩ, a key input operation can be identified. In a specific embodiment, 100KΩ can be used as a resistance change sensing range, with each 100KΩ change considered a change in pressure within that range. The range can also be adjusted as needed.

[0027] In a preferred embodiment, the organic carbon film resistor material can be obtained by depositing hydrocarbons such as gaseous methane and / or ethane through high-temperature vacuum thermal decomposition.

[0028] In a preferred embodiment, such as Figure 2 As shown, the PCB board is coated with 13 resistors. The first end (1) of resistor 1 (R1) is connected to the first pin (PA7) of the MCU; the first end (1) of resistor 2 (R2) is connected to the second pin (PA9) of the MCU (FDU_2856); the first end (1) of resistor 3 (R3) is connected to the third pin (IOVDD2) of the MCU; the first end (1) of resistor 4 (R4) is connected to the fourth pin (CSID0P) of the MCU; the second ends (2) of resistors 1, 2, 3, and 4 are connected to the fourteenth pin (CSID0N) of the MCU; the second end (2) of resistor 5 (R5) is connected to the fifth pin (PB4) of the MCU; the second end (2) of resistor 6 (R6) is connected to the sixth pin (PB3) of the MCU; the second end (2) of resistor 7 (R7) is connected to the seventh pin (PB2) of the MCU; the second end (2) of resistor 8 (R8) is connected to the eighth pin (PB1) of the MCU; and the second end (2) of resistor 13 (R4) is connected to the fourth pin (CSID0P) of the MCU. The second end (2) of resistor R13 is connected to the thirteenth pin (CSID1P) of the MCU. The first ends (1) of resistors 5, 6, 7, 8 and 13 are connected to the fifteenth pin (CSID1N) of the MCU. The second end (2) of resistor 9 (R9) is connected to the ninth pin (PB9) of the MCU. The second end (2) of resistor 10 (R10) is connected to the tenth pin (PB8) of the MCU. The second end (2) of resistor 11 (R11) is connected to the eleventh pin (PB7) of the MCU. The second end (2) of resistor 12 (R12) is connected to the twelfth pin (PB6) of the MCU. The first ends (1) of resistors 9, 10, 11 and 12 are connected to the sixteenth pin (PB5) of the MCU. The 13 resistors correspond to the 13 touch button icons on the touch metal plate.

[0029] In the diagram, U1 is the signal processing MCU FDU_2856, which detects changes in resistor value and performs calculations and analysis on these changes. J1 is a connector that transmits data with the main control chip of the smart lock, for example, for judging interrupt request IRQ signals. C1 is a power supply filter capacitor. The MCU's I2C communication pins (IIC_SDA and IIC_SCL) are connected to connector J1. The MCU communicates with the main control chip of the smart lock using I2C communication. R14 and R15 are I2C communication pull-up resistors.

[0030] In other implementations, users can design more or fewer resistors as needed, with different numbers of resistors corresponding to the number of different touch button icons on the touch metal plate. Touch icons can typically be number keys 0-9, *, #, doorbell button, deadbolt button, etc.

[0031] Figure 2 Each resistor in the circuit has two electrodes connected to a corresponding pin of the MCU. The MCU detects the change in resistance value after power is applied, thus acquiring the signal and enabling the judgment of human-machine interaction input. Resistors R1 to R13 are 13 identical pressure sensors, mounted on the bottom of the metal panel. The top layer of the metal panel is laser-engraved to form touch button icons to guide user input. The thickness of the metal panel can be designed between 1.2mm and 1.5mm for higher input sensitivity and a better user experience.

[0032] In the above-described embodiments of the present invention, when rainwater is applied to the metal surface of the pressure-sensitive top layer, the resistance of the pressure-sensitive device does not change, which can effectively prevent the panel from erroneously waking up and incorrectly inputting key values ​​due to water.

[0033] The present invention also discloses a smart door lock, wherein the smart door lock adopts the smart door lock touch sensing circuit described in any one of the present invention to realize the acquisition of user touch input signals.

[0034] Figure 3 The image shows a finished smart door lock designed according to the technical solution of the present invention. It can realize the touch sensing input design of the metal panel. The top of the metal panel has silkscreened characters on the surface, and the inside of the metal panel is designed with a pressure sensing input circuit.

[0035] In existing technologies, mainstream chip manufacturers design capacitive touch input methods. This capacitive touch input method cannot be implemented on metal panels; it can only be achieved on panels with plastic housings or glass surfaces. Furthermore, capacitive touch input chips cannot effectively prevent accidental operation when exposed to water. This invention utilizes a pressure-sensing micro-deformation design to effectively overcome this design deficiency.

[0036] The smart door lock touch sensing circuit of this invention is easy to implement. Simply place the coated printed resistor bridge patch on the top layer of the PCB board and then attach it directly below the metal panel. The pressure on the metal surface is transmitted to the pressure sensor resistor on the bottom layer. The MCU with a preset algorithm collects the resistance value and deformation parameter on the sensor, and the resistance value changes accordingly to realize the pressure sensing effect. At the same time, it can also effectively prevent the problem of false triggering or false input caused by water accumulation or water spray on the roof.

[0037] Those skilled in the art will understand that, without conflict, the above-mentioned preferred solutions can be freely combined and superimposed.

[0038] It should be understood that the above embodiments are merely exemplary and not restrictive. Various obvious or equivalent modifications or substitutions that can be made by those skilled in the art regarding the above details without departing from the basic principles of the present invention will be included within the scope of the claims of the present invention.

Claims

1. A smart door lock touch sensing circuit, characterized in that, Including PCB board and touch metal plate, One side of the PCB board is coated with multiple resistors, which are made of organic carbon film resistive material. The PCB board is also equipped with an MCU and a connector. The two terminals of each resistor are respectively connected to the corresponding pins of the MCU. The MCU is also connected to the connector, which is used to connect to the main controller of the smart door lock. The touch metal plate is disposed on one side of the PCB board coated with multiple resistors, and the touch metal plate is provided with multiple touch button icons that correspond one-to-one with the multiple resistors for user touch input; When any of the touch button icons is touched, the resistance value of the resistor corresponding to the touch button icon changes. The MCU detects the amount of resistance change of the resistor corresponding to the touch button icon. When the amount of resistance change is greater than a preset threshold, it is determined that a key input has occurred.

2. The smart door lock touch sensing circuit according to claim 1, characterized in that, The PCB board has pre-reserved coating positions for the multiple resistors, and then the organic carbon film resistor material is coated at those positions.

3. The smart door lock touch sensing circuit according to claim 2, characterized in that, The on-resistance of each of the resistors is 1 megohm.

4. The smart door lock touch sensing circuit according to claim 3, characterized in that, The preset threshold for the resistance change is 100KΩ.

5. The smart door lock touch sensing circuit according to claim 1, characterized in that, The organic carbon film resistor material is obtained by depositing gaseous methane and / or ethane through high-temperature vacuum thermal decomposition.

6. The smart door lock touch sensing circuit according to claim 1, characterized in that, The PCB board is coated with 13 resistors, among which, The first end of resistor 1 is connected to the first pin of the MCU, the first end of resistor 2 is connected to the second pin of the MCU, the first end of resistor 3 is connected to the third pin of the MCU, the first end of resistor 4 is connected to the fourth pin of the MCU, and the second ends of resistors 1, 2, 3 and 4 are connected to the fourteenth pin of the MCU. The second end of resistor 5 is connected to the fifth pin of the MCU, the second end of resistor 6 is connected to the sixth pin of the MCU, the second end of resistor 7 is connected to the seventh pin of the MCU, the second end of resistor 8 is connected to the eighth pin of the MCU, and the second end of resistor 13 is connected to the thirteenth pin of the MCU. The first ends of resistors 5, 6, 7, 8 and 13 are connected to the fifteenth pin of the MCU. The second end of resistor 9 is connected to the ninth pin of the MCU, the second end of resistor 10 is connected to the tenth pin of the MCU, the second end of resistor 11 is connected to the eleventh pin of the MCU, the second end of resistor 12 is connected to the twelfth pin of the MCU, and the first ends of resistors 9, 10, 11 and 12 are connected to the sixteenth pin of the MCU.

7. The smart door lock touch sensing circuit according to claim 1, characterized in that, The I2C communication pin of the MCU is connected to the connector, and the MCU communicates with the main controller of the smart door lock using the I2C communication method.

8. The smart door lock touch sensing circuit according to claim 1, characterized in that, The thickness of the touch metal plate is 1.2mm to 1.5mm.

9. The smart door lock touch sensing circuit according to claim 1, characterized in that, The top layer of the touch metal plate is laser-engraved to form the touch button icon.

10. A smart door lock, characterized in that, The smart door lock employs the smart door lock touch sensing circuit as described in any one of claims 1-9 to realize the acquisition of user touch input signals.

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