Control system and method for controlling CEC control screen state based on HDMI interface

Abstract

The invention relates to a control system and method for controlling the state of a CEC control screen based on an HDMI interface. The control system comprises a microcontroller module, a dynamic channel switching module, a hybrid level conversion module and third-party software communication. The control system and method are ingenious in design, and intelligent control over the HDMI equipment is achieved through the microcontroller module MCU. An HPD signal level state of an HDMI interface is detected through an HPD signal processing circuit, an MCU is triggered to be interrupted when an HPD high level is detected, and after a display EDID signal is transmitted to the MCU through a DDC channel, a DDC channel of a display can be switched to an X86 platform through a DDC channel selection circuit according to a level signal; the conversion between the MCU logic level and the CEC signal level of the HDMI interface can be realized according to the hybrid level conversion module; cooperative work of display state and brightness adjustment can be realized through communication cooperation of multiple pieces of hardware and third-party software and accurate time sequence control. The method is low in cost, high in response speed and suitable for high-cost-performance HDMI control scenes such as education large screens and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of video devices, and more specifically, to a control system and method for controlling the state of a CEC control screen based on an HDMI interface. Background Art

[0002] With the popularization of the Open Pluggable Specification (OPS) in the education large-screen industry, the interconnection control requirements between TVs and PCs have become increasingly urgent. As a dedicated control channel for TVs and PCs, CEC has made it a normal requirement to control the state of the HDMI CEC control screen. In traditional technologies, there are mainly two technical solutions for implementing the function of controlling the state of the CEC control screen on the HDMI of the X86 platform of the PC:

[0003] 1. FPGA solution: Implementing CEC protocol parsing using a field-programmable gate array has problems such as high development complexity, large hardware area, and high cost, which is not conducive to product miniaturization and mass production.

[0004] 2. Dedicated CEC chip solution: Implementing CEC functions using an application-specific integrated circuit. Although it reduces the development difficulty, there are still technical defects such as high hardware cost (chip unit price > $0.5) and large circuit layout area (> 10mm 2 ).

[0005] Both of the above solutions are difficult to meet the strict requirements of education large-screen devices for cost control (BOM cost requirement < $0.2) and hardware size (PCB area < 5mm 2 ). In addition, the existing technical solutions have a response delay (typical value > 500ms) in the timing coordination of HPD signal processing and EDID information acquisition, which affects the user experience. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a control system and method for controlling the state of a CEC control screen based on an HDMI interface in view of the above-mentioned defects of the prior art.

[0007] On the one hand, the technical solution adopted by the present invention to solve its technical problem is: A control system for controlling the state of a CEC control screen based on an HDMI interface, comprising:

[0008] A microcontroller module, the microcontroller module is connected to the X86 platform and receives signals from an HDMI display through the HDMI interface. The microcontroller module has at least one UART interface and one DDC interface; the microcontroller module obtains EDID information from the display through the DDC interface and activates the DDC channel after receiving the HPD signal;

[0009] The dynamic channel switching module includes an HPD signal processing circuit for detecting the HPD signal level status of the HDMI interface and triggering an interrupt of the microcontroller module when detecting an HPD high level;

[0010] and a DDC channel selection circuit for, after the microcontroller module finishes reading the EDID, by pulling down the level of the DDC_EN_microcontroller module_PB9 pin, after the display EDID signal is transmitted to the MCU through the DDC channel, switching the DDC channel of the display to the X86 platform;

[0011] The hybrid level conversion module includes a CEC signal level conversion circuit, which uses a bidirectional level conversion chip and a pull-up resistor to implement the conversion between the 3.3V logic level of the microcontroller module and the 5V CEC signal level of the HDMI interface;

[0012] The control system is further configured with third-party software communication for controlling the brightness status of the HDMI display. The third-party software communication is installed on the X86 platform and sends brightness control instructions to the microcontroller module through the UART protocol; the microcontroller module processes the CEC signal from the HDMI interface and sends the brightness control instructions to the HDMI display through the UART interface.

[0013] For the control system of the present invention, wherein, the HPD signal processing circuit includes a three-stage amplifier circuit, an RC delay network, and a dual-channel voltage dividing resistor network; the specific topology of the three-stage amplifier circuit includes resistors R179 and R184 and transistor Q38.

[0014] For the control system of the present invention, wherein, the working timing of the dynamic channel switching module is as follows:

[0015] Disable the HPD_SOC channel during the t0 - t1 stage (EDID reading period);

[0016] Enable the DDC_SOC_EN signal during the t1 - t2 stage (display period);

[0017] The switching time interval Δt = 200ms ± 50ms, which is controlled by the internal timer TIM6 of the microcontroller module.

[0018] For the control system of the present invention, wherein, the chip model of the microcontroller module is APM32F051C8T6; the interface configuration of the microcontroller module includes:

[0019] The PB1 pin is configured as an interrupt trigger input mode;

[0020] The PB9 pin is configured as an open-drain output mode;

[0021] The USART1 interface is configured in the asynchronous communication mode with a baud rate of 9600 bps ± 2%.

[0022] In the control system of the present invention, the hybrid level conversion module uses a chip model of SN74LVC2T45, and its operating voltage is configured as follows:

[0023] VCCA = 3.3V (connected to the microcontroller module side);

[0024] VCCB = 5V (connected to the HDMI interface side);

[0025] The bus matching resistors R600 = R576 = 4.7 kΩ ± 5%.

[0026] In the control system of the present invention, the brightness control instruction format of the CEC communication module is as follows:

[0027] Instruction frame structure: start code 0x8F + brightness value (0x00 - 0x64) + checksum;

[0028] The CEC physical layer driver circuit includes a 2N7002 MOS transistor, with its gate resistor R525 = 100 Ω ± 5% and drain resistor R531 = 1 kΩ ± 5%.

[0029] In the control system of the present invention, the microcontroller module is connected to the X86 platform of the PC and the HDMI display through circuit components: the circuit components include a resistor and capacitor component for transmitting the HPD signal, a DDC channel component for transmitting the EDID information, and a CEC line component for transmitting the CEC signal.

[0030] In the control system of the present invention, the circuit components further include at least one pull-up resistor to ensure stable signal transmission.

[0031] On the other hand, the present invention also provides a control method using the control system as described in any one of the above, which includes the following steps:

[0032] Start the X86 platform of the PC and obtain the EDID information of the connected HDMI display through the microcontroller module;

[0033] The microcontroller module obtains the EDID information of the HDMI display through the DDC channel of the HDMI interface and confirms the HPD signal of the HDMI display;

[0034] The microcontroller module turns on the DDC and HPD channels of the HDMI display and allows the X86 platform to communicate with the HDMI display normally;

[0035] After the HDMI display is ready, third-party software on the X86 platform sends a control command to the microcontroller module through the UART interface;

[0036] The microcontroller module receives the control command and forwards it to the HDMI display through the CEC channel to control the brightness state of the HDMI display.

[0037] In the control method of the present invention, after receiving the HPD signal of the HDMI display, the microcontroller module activates the corresponding DDC and HPD channels, enabling the X86 platform to correctly identify the HDMI display and establish a communication link with it.

[0038] The beneficial effects of the present invention are as follows: The control system and method are ingeniously designed. Through the dynamic channel switching technology and the mixed-signal processing architecture, the microcontroller module is used to realize the intelligent control of HDMI devices. The HPD signal processing circuit detects the HPD signal level state of the HDMI interface and triggers the MCU interrupt when the HPD high level is detected; the DDC channel selection circuit can switch the DDC channel of the display to the X86 platform according to the level signal; according to the mixed-level conversion module, the conversion between the MCU logic level and the CEC signal level of the HDMI interface can be realized; through the cooperation of the above-mentioned multiple hardware and third-party software communication and precise timing control, the coordinated operation of the display state and brightness adjustment can be realized. Compared with the traditional scheme, the hardware cost is reduced and the response speed is further improved, which is especially suitable for scenarios such as education large screens that require high-cost-effective HDMI control. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will further illustrate the present invention in conjunction with the drawings and embodiments. The drawings in the following description are only partial embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts:

[0040] Figure 1 is the circuit diagram of the microcontroller module in Embodiment 1 of the present invention;

[0041] Figure 2 is the partial circuit of the DDC channel selection circuit in Embodiment 1 of the present invention Figure 1 ;

[0042] Figure 3 is the partial circuit of the DDC channel selection circuit in Embodiment 1 of the present invention Figure 2

[0043] Figure 4It is the circuit diagram of the HPD signal processing circuit in the first embodiment of the present invention;

[0044] Figure 5 It is the circuit diagram of the CEC signal level conversion circuit in the first embodiment of the present invention;

[0045] Figure 6 It is the circuit diagram of the CEC physical layer driver circuit in the first embodiment of the present invention;

[0046] Figure 7 It is the flowchart of the control method in the second embodiment of the present invention. Detailed implementation manners

[0047] Terms such as "first", "second", "third", and "fourth" in the specification and claims of the present invention and the accompanying drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the listed steps or modules, but optionally further includes steps or modules not listed, or optionally further includes other steps or modules inherent to these processes, methods, products, or devices.

[0048] Referring to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present invention. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0049] "Plurality" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0050] Moreover, terms indicating directions such as "upper, lower, front, rear, left, right, upper end, lower end, longitudinal" etc. are all referenced based on the attitude position of the device or equipment described in this solution during normal use.

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are partial embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0052] Embodiment 1:

[0053] A control system for controlling the state of a CEC control screen based on an HDMI interface in a preferred embodiment of the present invention, as Figures 1-6 shown, includes a microcontroller module, a dynamic channel switching module, and a mixed-level conversion module: Among them:

[0054] Microcontroller module MCU:

[0055] The microcontroller module MCU is connected to the X86 platform of the PC and the HDMI display through circuit components and receives their signals: In this embodiment, the circuit components include a resistor and capacitor component for transmitting the HPD signal, a DDC channel component for transmitting EDID information, and a CEC line component for transmitting the CEC signal.

[0056] Optionally, the circuit components further include at least one pull-up resistor to ensure stable signal transmission;

[0057] Furthermore, the microcontroller module has at least one UART interface and one DDC interface; the microcontroller module obtains EDID information from the display through the DDC interface and activates the DDC channel after receiving the HPD signal.

[0058] Optionally, the working process of EDID information reading and writing is as follows:

[0059] Through the I 2 C interface (SCL: PA11, SDA: PA12), read the EDID data at a rate of 100 kHz;

[0060] Verify the EDID header flag (00FF FF FF FF FF FF 00);

[0061] Store the valid EDID in the address range of 0x0800F000 - 0x0800F100 in Flash.

[0062] In this embodiment, the chip model of the microcontroller module is APM32F051C8T6; the interface configuration of the microcontroller module includes:

[0063] The PB1 pin is configured as an interrupt-triggered input mode;

[0064] The PB9 pin is configured as an open-drain output mode;

[0065] The USART1 interface is configured as an asynchronous communication mode with a baud rate of 9600 bps ± 2%.

[0066] The dynamic channel switching module includes an HPD signal processing circuit and a DDC channel selection circuit.

[0067] Among them, the HPD signal processing circuit is used to detect the HPD signal level status of the HDMI interface, trigger the microcontroller module interrupt when detecting HPD high level, and generate an enable signal with a preset delay time (50 ms ± 10 ms) through an RC delay circuit (R666 = 1 kΩ, C101 = 100 nF);

[0068] In this embodiment, the HPD signal processing circuit includes a three-stage amplifier circuit, an RC delay network, and a dual-channel voltage-dividing resistor network; the specific topology of the three-stage amplifier circuit includes resistors R179 and R184 and transistor Q38.

[0069] As Figure 2 and as Figure 3 shown, the DDC channel selection circuit includes a MOS transistor switch array (Q26, Q52) and a voltage-dividing resistor network (R662 = 100 Ω, R672 = 4.7 kΩ), and is used to switch the DDC channel of the display to the X86 platform after the MCU completes the EDID reading by pulling down the level of the DDC_EN_MCU_PB9 pin and after the display EDID signal is transmitted to the MCU through the DDC channel;

[0070] Further, the working timing of the dynamic channel switching module is as follows:

[0071] Disable the HPD_SOC channel during the t0 - t1 stage (EDID reading period);

[0072] Enable the DDC_SOC_EN signal during the t1 - t2 stage (display period);

[0073] The switching time interval Δt = 200 ms ± 50 ms, which is controlled by the internal timer TIM6 of the microcontroller module. The hybrid level conversion module includes a CEC signal level conversion circuit.

[0074] Among them, as Figure 4 shown, the CEC signal level conversion circuit uses a bidirectional level conversion chip (U32, model SN74LVC2T45) and pull-up resistors (R600 = 4.7 kΩ, R576 = 4.7 kΩ) to realize the conversion between the 3.3V logic level of the microcontroller module and the 5V CEC signal level of the HDMI interface;

[0075] Furthermore, the CEC signal level conversion circuit further includes a CEC driving circuit, which is composed of a 2N7002 MOS transistor (Q64), a current limiting resistor (R525 = 100Ω), and a pull-down resistor (R531 = 1kΩ), and is used to enhance the driving ability of the CEC signal.

[0076] In this embodiment, the hybrid level conversion module can also adopt the chip model SN74LVC2T45, and its working voltage is configured as:

[0077] VCCA = 3.3V (connected to the microcontroller module side);

[0078] VCCB = 5V (connected to the HDMI interface side);

[0079] The bus matching resistors R600 = R576 = 4.7kΩ ± 5%.

[0080] Furthermore, the control system is further configured with third-party software communication for controlling the brightness state of the HDMI display. The third-party software communication is installed on the X86 platform and sends brightness control instructions to the microcontroller module through the UART protocol; the microcontroller module processes the CEC signal from the HDMI interface and sends the brightness control instructions to the HDMI display through the UART interface.

[0081] Among them, the brightness control instruction format of the CEC communication module is:

[0082] Instruction frame structure: start code + brightness value (0x00 - 0x64) + check code;

[0083] The CEC physical layer driving circuit includes a 2N7002 MOS transistor, whose gate resistor R525 = 100Ω ± 5% and drain resistor R531 = 1kΩ ± 5%. Through the third-party software instruction format (0x8F + brightness value + check code) and the CEC protocol conversion logic of the MCU (OPCODE: 0x84), a full-link protection from software instructions to hardware signals is formed, clarifying the accuracy of the brightness adjustment accuracy and reflecting the characteristics of quantifiable brightness adjustment.

[0084] The working process of the third-party software communication is as follows:

[0085] In the initialization stage, the GPIO mode and interrupt priority are configured (the priority of EXTI4_15_IRQn is 1);

[0086] Zero-wait transmission of CEC data is achieved through the DMA channel (DMA1_Channel2);

[0087] The CEC instructions are parsed using the look-up table method, and the instruction mapping table is stored at the starting address of 0x0800E000.

[0088] By parsing the control instructions received through the UART interface, a control frame (OPCODE: 0x84) that conforms to the HDMI CEC protocol standard is generated, and the CEC signal is transmitted to the 13th pin of the HDMI interface via the hybrid level conversion module to achieve precise adjustment of the brightness of the display device (adjustment accuracy ±1%).

[0089] The specific principle is as follows:

[0090] PC X86 powers on -->

[0091] The monitor is connected to HDMI1 -->

[0092] The 19th PIN of HDMI1 is at a high level, passing through R179 and R184, Q38, R666, R667 -->

[0093] HDP_MCU_EN_PB1 (the 19th PIN of MU1) is at a high level --->

[0094] The 15th PIN SCL signal and the 16th PIN SDA signal of HDMI1 give out the EDID information -->

[0095] Passing through R636, R637, the 6th PIN and the 7th PIN of U38 -->

[0096] The 2nd PIN and the 3rd PIN of U38 are combined with the external pull-up resistors R627 and R628 -->

[0097] The 43rd PIN and the 42nd PIN of MU1 obtain the EDID of the TV -->

[0098] The HPD channel is opened, HDP_MCU_EN_PB10 (the 21st PIN of MU1) is pulled low, passing through R670, R672, HDMI_HPD_SOC_EN_N is pulled low -->

[0099] The third PIN of Q52 is pulled high through R416 -->

[0100] PC X86 receives the HPD high signal from the TV -->

[0101] The DDC channel of the SOC is opened. Through the 46th PIN DDC_EN_MCU_PB9 of MU1 being pulled low, via R662, DDC_SOC_EN_N is pulled low, the third PIN of Q26 is at a high level, the 5th PIN of U31 is at a high level, enabling is effective, and the 6th PIN and the 7th PIN EDID signals of U31 are transmitted to PC X86 through the 2nd PIN and the 3rd PIN -->

[0102] After normal display, access the MU1 USART1 CEC through a third-party software to implement TV brightness control: CEC_SIO_MCU_TX and CEC_SIO_MCU_RX-->

[0103] The 4th PIN and 5th PIN of U32 and the corresponding pull-up resistors R600, R576-->

[0104] The 30th PIN and 31st PIN of MU1-->

[0105] Third-party software-->

[0106] The CEC signal of the 15th PIN of MU1 passes through R525, Q64, R531-->

[0107] The CEC signal of the 13th PIN of HDM1-->

[0108] Brightness control of the TV.

[0109] The control system and method are ingeniously designed. Through the dynamic channel switching technology and the mixed-signal processing architecture, the microcontroller module MCU is used to realize the intelligent control of HDMI devices. The HPD signal processing circuit detects the HPD signal level state of the HDMI interface and triggers an MCU interrupt when the HPD high level is detected; the DDC channel selection circuit can switch the DDC channel of the display to the X86 platform according to the level signal; according to the mixed level conversion module, the conversion between the MCU logic level and the CEC signal level of the HDMI interface can be realized; through the cooperation of the above-mentioned multiple hardware and the third-party software communication and precise timing control, the coordinated operation of the display state and brightness adjustment can be realized. It has low cost and fast response speed, and is suitable for high-cost-effective HDMI control scenarios such as large educational screens.

[0110] Embodiment 2:

[0111] The present invention also provides a control method using the control system described in Embodiment 1 above, as Figure 7 shown, including the following steps:

[0112] S10: Start the X86 platform of the PC and obtain the EDID information of the connected HDMI display through the microcontroller module;

[0113] S20: The microcontroller module obtains the EDID information of the HDMI display through the DDC channel of the HDMI interface and confirms the HPD signal of the HDMI display;

[0114] S30: The microcontroller module opens the DDC and HPD channels of the HDMI display and allows the X86 platform to communicate with the HDMI display normally;

[0115] S40: After the HDMI monitor is ready, third-party software on the X86 platform sends control commands to the microcontroller module through the UART interface;

[0116] S50: The microcontroller module receives the control commands and forwards them to the HDMI monitor through the CEC channel to control the brightness state of the HDMI monitor.

[0117] Furthermore, after receiving the HPD signal of the HDMI monitor, the microcontroller module activates the corresponding DDC and HPD channels, enabling the X86 platform to correctly identify the HDMI monitor and establish a communication link with it.

[0118] The control system and method are ingeniously designed. Through the dynamic channel switching technology and the mixed-signal processing architecture, the microcontroller module MCU is used to achieve intelligent control of HDMI devices. The HPD signal processing circuit detects the HPD signal level state of the HDMI interface and triggers an MCU interrupt when the HPD high level is detected; the DDC channel selection circuit can switch the DDC channel of the monitor to the X86 platform according to the level signal; the mixed-level conversion module can achieve the conversion between the MCU logic level and the CEC signal level of the HDMI interface; through the cooperation of the above-mentioned multiple hardware and third-party software communication and precise timing control, the coordinated operation of the monitor state and brightness adjustment can be achieved. It has low cost and fast response speed, and is suitable for scenarios with high cost performance HDMI control such as large educational screens.

[0119] It should be understood that those of ordinary skill in the art can make improvements or transformations according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of the present invention.

Claims

1. A control system for controlling the state of a CEC control screen based on an HDMI interface, characterized in that, Comprising: A microcontroller module, which is connected to the X86 platform and receives signals from an HDMI monitor through an HDMI interface. The microcontroller module has at least one UART interface and one DDC interface; the microcontroller module obtains EDID information from the monitor through the DDC interface and activates the DDC channel after receiving the HPD signal; A dynamic channel switching module, including an HPD signal processing circuit, which is used to detect the HPD signal level status of the HDMI interface and trigger an interrupt of the microcontroller module when detecting HPD high level; And a DDC channel selection circuit, which is used to, after the microcontroller module finishes reading the EDID, switch the DDC channel of the monitor to the X86 platform after pulling down the level of the DDC_EN_microcontroller module_PB9 pin, and the EDID signal of the monitor is transmitted to the MCU through the DDC channel; A hybrid level conversion module, including a CEC signal level conversion circuit, which uses a bidirectional level conversion chip and a pull-up resistor to realize the conversion between the 3.3V logic level of the microcontroller module and the 5V CEC signal level of the HDMI interface; The control system is further configured with third-party software communication for controlling the brightness state of the HDMI monitor. The third-party software communication is installed on the X86 platform and sends brightness control instructions to the microcontroller module through the UART protocol; the microcontroller module processes the CEC signal from the HDMI interface and sends the brightness control instructions to the HDMI monitor through the UART interface.

2. The control system for controlling the state of the CEC control screen based on the HDMI interface according to claim 1, wherein The HPD signal processing circuit includes a three-stage amplifier circuit, an RC delay network, and a dual-channel voltage dividing resistor network; the specific topological structure of the three-stage amplifier circuit includes resistors R179 and R184 and transistor Q38.

3. The control system for controlling the status of the CEC control screen based on the HDMI interface according to claim 1 or 2, characterized in that, The working timing of the dynamic channel switching module is as follows: Disable the HPD_SOC channel during the t0 - t1 stage (EDID reading period); Enable the DDC_SOC_EN signal during the t1 - t2 stage (display period); The switching time interval Δt = 200ms ± 50ms, which is controlled by the internal timer TIM6 of the microcontroller module.

4. The control system for controlling the state of the CEC control screen based on the HDMI interface according to claim 1, wherein, The chip model of the microcontroller module is APM32F051C8T6; The interface configuration of the microcontroller module includes: The PB1 pin is configured as an interrupt trigger input mode; The PB9 pin is configured as an open-drain output mode; The USART1 interface is configured as an asynchronous communication mode with a baud rate of 9600bps ± 2%; 5. The control system for controlling the state of a CEC control screen based on an HDMI interface according to claim 1, wherein The hybrid level conversion module uses a chip model of SN74LVC2T45, and its working voltage configuration is: VCCA = 3.3V (connected to the microcontroller module side); VCCB = 5V (connected to the HDMI interface side); The bus matching resistors R600 = R576 = 4.7kΩ ± 5%; 6. The control system for controlling the state of the CEC control screen based on the HDMI interface according to claim 1, wherein The brightness control instruction format of the CEC communication module is: Instruction frame structure: start code 0x8F + brightness value (0x00 - 0x64) + checksum; The CEC physical layer driver circuit includes a 2N7002 MOS transistor, with its gate resistor R525 = 100Ω ± 5% and drain resistor R531 = 1kΩ ± 5%.

7. The control system for controlling the state of a CEC control screen based on an HDMI interface according to any one of claims 1-6, characterized in that The microcontroller module is connected to the X86 platform of the PC and the HDMI display through circuit components: The circuit components include a resistor and capacitor component for transmitting the HPD signal, a DDC channel component for transmitting EDID information, and a CEC line component for transmitting the CEC signal.

8. The control system and method for controlling the state of a CEC control screen based on an HDMI interface according to claim 7, wherein, The circuit component also includes at least one pull-up resistor to ensure stable signal transmission.

9. A control method using the control system according to any one of claims 1-8, characterized in that, It includes the following steps: Start the X86 platform of the PC and obtain the EDID information of the connected HDMI display through the microcontroller module; The microcontroller module obtains the EDID information of the HDMI display through the DDC channel of the HDMI interface and confirms the HPD signal of the HDMI display; The microcontroller module turns on the DDC and HPD channels of the HDMI display and allows the X86 platform to communicate with the HDMI display normally; When the HDMI display is ready, a third-party software on the X86 platform sends a control command to the microcontroller module through the UART interface; The microcontroller module receives the control command and forwards it to the HDMI display through the CEC channel to control the brightness state of the HDMI display.

10. The control method according to claim 9, characterized in that, The microcontroller module activates the corresponding DDC and HPD channels after receiving the HPD signal of the HDMI display, enabling the X86 platform to correctly identify the HDMI display and establish a communication link with it.

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