Hardware circuit for resisting electromagnetic interference of touch screen and control method

Abstract

The invention discloses an anti-electromagnetic interference hardware circuit for a touch screen and a control method. The circuit comprises the touch screen, a controller and a diode, the touch screen and the controller are connected through a communication line, and the communication line comprises an SDA data line and a reset control line; the SDA data line and the reset control line are connected through a diode; the controller is used for receiving signals of the touch screen, and when it is detected that data are abnormal, the interfered touch screen is reset and restarted through the diode. According to the invention, the chip is reset after the abnormality is judged through the control software, and the control software is matched with the improvement of the touch screen control circuit, so that the situation that the touch screen does not work due to electromagnetic interference can be effectively reduced.

Description

Technical Field

[0001] The present invention belongs to the field of electronic engineering technology, and more specifically, relates to a method and a hardware circuit for resisting electromagnetic interference of a touch screen. Background Art

[0002] Touch screens are widely used in the industrial field and are an essential and important component for human-computer interaction in various instruments and equipment. The electromagnetic field environment in the industrial field is complex, and whether the touch screen can work normally in this electromagnetic environment is something that every product designer must seriously consider.

[0003] The sources of electromagnetic interference in the touch screen system may come from multiple aspects, including power supply, signal line, grounding system, etc. Power supply interference such as insufficiently filtered switching power supply noise, signal line interference such as electromagnetic radiation and coupling, and imperfect grounding system can all cause electromagnetic interference. Under strong electromagnetic interference, mainly electrostatic discharge interference to the touch screen, will cause the I2C bus to work abnormally or not work. The phenomenon is that the controller can receive the interrupt response signal, but there is no SDA data. Especially in the case of contact discharge 6KV and air discharge 8KV, the touch screen will appear black screen, touch failure, and cannot be restored.

[0004] In order to reduce electromagnetic interference, more optimization is needed in hardware design and layout, such as using isolation transformers, filters, magnetic beads and capacitors, etc. These measures will increase the complexity and cost of the system, and the effect may not be very good, and the touch screen will also fail.

[0005] The prior art document (CN118689345A) discloses a complex environment anti-interference circuit device for a capacitive touch screen. The document mainly discharges or shields external interference signals through complex hardware circuits, and then resets them through a reset circuit. The hardware cost is high and the system complexity is too high. Summary of the invention

[0006] In order to solve the deficiencies in the prior art, the present invention provides a hardware circuit and a control method for a touch screen to resist electromagnetic interference.

[0007] The present invention adopts the following technical solution.

[0008] A first aspect of the present invention provides a hardware circuit for touch screen anti-interference, comprising: a touch screen, a controller and a diode; The touch screen and the controller are connected via a communication line, which includes an SDA data line and a reset control line; Connect the SDA data line and the reset control line through a diode; The controller is used to receive touch screen signals, and when data abnormality is detected, the disturbed touch screen is reset and restarted through the diode.

[0009] The SDA pin of the touch screen is connected to the SDA pin of the controller through an SDA data line, and the SCL pin of the touch screen is connected to the SCL pin of the controller through an SCL clock line.

[0010] The INT pin of the touch screen is connected to the INT pin of the controller, and the RST pin of the touch screen is connected to the RST pin of the controller through a reset control line.

[0011] A second aspect of the present invention provides a method for controlling a hardware circuit for resisting electromagnetic interference of a touch screen, based on the above-mentioned hardware circuit for resisting electromagnetic interference of a touch screen, characterized in that it includes: When a touch occurs, the touch screen sends a touch screen signal; When the controller receives a touch screen signal sent by the touch screen, it detects the position coordinate information in the touch screen signal; If there is an abnormality in the position coordinate information, the timer is started and the position coordinate information is continuously detected within the set time; If the position coordinate information is detected again within the set time and still abnormal, the touch screen is reset and restarted through the reset control line and the diode.

[0012] Preferably, the touch screen signal includes: position information, an interrupt response signal and a reset signal.

[0013] Preferably, when a touch occurs, the INT pin of the touch screen sends an interrupt response signal, and at the same time the SDA pin and SCL pin of the touch screen send position information, which is transmitted to the controller through the SDA data line and the SCL clock line.

[0014] Preferably, the detection position coordinate information includes: When the INT pin of the controller receives the interrupt response signal sent by the touch screen, it detects whether the position coordinate information in the data received by the SDA pin is 0. If it is not 0, the position coordinate information is normal. If it is 0, it is temporarily considered that the position coordinate information is abnormal.

[0015] Preferably, after the timer is started, if an interrupt response signal is received within a set time, it indicates that a touch has occurred, and the position coordinate information is detected again to see if it is 0. If it is not 0, it indicates that the position coordinate information is normal, and the timer is cleared.

[0016] Preferably, if the position coordinate information detected again is still 0, it is considered to be a true data anomaly, the timer is cleared and the chip reset program is started.

[0017] Preferably, the controller RST pin sends a reset signal, and the SDA pin is forced to be pulled to a low level through a diode, so that the internal chip of the touch screen is reset and restarted.

[0018] Compared with the prior art, the beneficial effects of the present invention include at least: the abnormality judgment realized by the control software and then resetting the chip, and coordinated with the improvement of the touch screen control circuit, can effectively reduce the occurrence of touch screen malfunction caused by electromagnetic interference, and can effectively resist the electrostatic discharge test of contact discharge 10KV and air discharge 15KV, the screen will not be black, and touch failure can be restored in 2 to 3 seconds. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the circuit of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0021] like Figure 1 As shown, Embodiment 1 of the present invention provides a touch screen anti-interference circuit, comprising: The touch screen is connected to the controller through a communication line, specifically, the SDA pin of the touch screen is connected to the SDA pin of the controller through the SDA data line, the SCL pin of the touch screen is connected to the SCL pin of the controller through the SCL clock line, the INT pin of the touch screen is connected to the INT pin of the controller, and the RST pin of the touch screen is connected to the RST pin of the controller through the reset control line. The SDA data line is connected to the reset control line through a diode.

[0022] The controller is used to receive touch screen signals, and when data abnormality is detected, the disturbed touch screen is reset and restarted.

[0023] Adding a diode between SDA and RST and resetting the RST pin can effectively improve the anti-interference ability of the touch screen.

[0024] Embodiment 2 of the present invention provides a method for resisting electromagnetic interference of a touch screen, based on the circuit for resisting electromagnetic interference of a touch screen described in Embodiment 1, including: Touch screen signals include: position information, interrupt response signal and reset signal. Position information is transmitted by I2C bus: two signal lines SDA and SCL, SDA data line, SCL clock line. Interrupt response signal: INT. Reset signal: RST.

[0025] Strong electromagnetic interference may cause the I2C bus to work abnormally or not work. The phenomenon is that the controller can receive the interrupt response signal, but there is no SDA data.

[0026] 1) When the touch screen is touched, the SDA and SCL pins of the touch screen send position information, which is transmitted to the controller through the SDA data line and the SCL clock line. The INT pin of the touch screen sends an interrupt response signal. When the INT pin of the controller receives the interrupt response signal sent by the touch screen, it detects whether there is any abnormality in the position coordinate information in the SDA data, that is, checks whether the position coordinate information is "0". If it is not "0", the data is normal. If it is "0", the data is temporarily considered abnormal.

[0027] 2) Start the timer when the data is abnormal. If an interrupt response signal is received within the set time, it means that a touch has occurred. Execute according to step 1. If the data is not "0" this time, clear the timer. If it is still "0", it is considered to be a true data abnormality. Similarly, clear the timer and start the chip reset program. The controller RST pin gives a reset signal. When RST gives a reset signal, that is, the signal level is 0, the SDA pin is also forced to be pulled to a low level through the diode, so that the chip inside the touch screen is reset and restarted. After the abnormal data of the touch screen disappears, return to step 1. In the present invention, the set time is 5s.

[0028] When there is an interrupt response signal, the position coordinate information in the SDA data cannot be detected, indicating that the I2C bus is seriously interfered with. The touch screen chip is reset to restore the chip to its initial state so that it can work normally again. The above steps can effectively reduce the occurrence of touch screen failure caused by electromagnetic interference, and the ideal state can be achieved through cooperation with circuit improvements.

[0029] As a prominent substantial feature of the present invention and one of the significant advances brought to the prior art, the present invention realizes touch screen anti-interference by coordinating control software and circuit improvements, and realizes anti-interference effect on the basis of a simpler circuit structure with low cost and good effect.

[0030] Embodiment 3 of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is loaded into the processor, a method for resisting electromagnetic interference of a touch screen according to embodiment 2 is implemented.

[0031] Embodiment 4 of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for resisting electromagnetic interference of a touch screen according to embodiment 2 is implemented.

[0032] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A hardware circuit for anti-electromagnetic interference of a touch screen, characterized in that: include: Touch screen, controller and diode; The touch screen and the controller are connected via a communication line, which includes an SDA data line and a reset control line; Connect the SDA data line and the reset control line through a diode; The controller is used to receive touch screen signals, and when data abnormality is detected, the disturbed touch screen is reset and restarted through the diode.

2. A hardware circuit for anti-electromagnetic interference of a touch screen as claimed in claim 1, characterized in that: The SDA pin of the touch screen is connected to the SDA pin of the controller through an SDA data line, and the SCL pin of the touch screen is connected to the SCL pin of the controller through an SCL clock line.

3. A hardware circuit for anti-electromagnetic interference of a touch screen as claimed in claim 2, characterized in that: The INT pin of the touch screen is connected to the INT pin of the controller, and the RST pin of the touch screen is connected to the RST pin of the controller through a reset control line.

4. A method for controlling a hardware circuit for resisting electromagnetic interference of a touch screen, based on a hardware circuit for resisting electromagnetic interference of a touch screen according to any one of claims 1 or 3, characterized in that: include: When a touch occurs, the touch screen sends a touch screen signal; When the controller receives a touch screen signal sent by the touch screen, it detects the position coordinate information in the touch screen signal; If there is an abnormality in the position coordinate information, the timer is started and the position coordinate information is continuously detected within the set time; If the position coordinate information is detected to be abnormal again within the set time, the controller resets and restarts the touch screen through the reset control line and the diode.

5. A method for controlling a hardware circuit for a touch screen to resist electromagnetic interference as claimed in claim 4, characterized in that: Touch screen signals include: position coordinate information, interrupt response signal and reset signal.

6. A method for controlling a hardware circuit for a touch screen to resist electromagnetic interference as claimed in claim 4, characterized in that: When a touch occurs, the INT pin of the touch screen sends an interrupt response signal, and at the same time the SDA pin and SCL pin of the touch screen send position coordinate information, which is transmitted to the controller through the SDA data line and the SCL clock line.

7. A method for controlling a hardware circuit for a touch screen to resist electromagnetic interference as claimed in claim 4, characterized in that: The detection position coordinate information includes: When the INT pin of the controller receives the interrupt response signal from the touch screen, it detects whether the position coordinate information in the data received by the SDA pin is 0. If it is not 0, the position coordinate information is normal. If it is 0, it is temporarily considered abnormal and the timer is started.

8. A method for controlling a hardware circuit for a touch screen to resist electromagnetic interference as claimed in claim 4, characterized in that: After the timer is started, if an interrupt response signal is received within the set time, it means that a touch has occurred. The position coordinate information is checked again to see if it is 0. If it is not 0, it means that the position coordinate information is normal and the timer is cleared.

9. A method for controlling a hardware circuit for a touch screen to resist electromagnetic interference as claimed in claim 8, characterized in that: If the position coordinate information detected again is still 0, it is determined that there is an abnormality in the position coordinate information, the timer is cleared and the chip reset program is started.

10. A method for controlling a hardware circuit for a touch screen to resist electromagnetic interference as claimed in claim 9, characterized in that: The controller RST pin sends a reset signal, which is transmitted to the touch screen through the reset control line, and the SDA pin is forced to a low level through a diode, so that the internal chip of the touch screen is reset and restarted.

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