Same-screen device circuit capable of USB master-slave switching

Abstract

The utility model belongs to a same-screen device, and particularly relates to a same-screen device circuit capable of USB master-slave switching, which is characterized by comprising a display screen; a connection interface; the main processor is used for processing the MIRACAST protocol or the AIRCAST protocol in the data signal of the connection interface on the same screen; the MCU is used for carrying out master-slave switching on the main processor which is used for analyzing voltage and signals of the connecting interface so as to control the main processor, the MCU is connected with the main processor, the display screen is connected with the main processor, and the MCU and the main processor are both connected with the connecting interface. According to the utility model, through the master-slave switching function of the circuit, a user can select the connection mode between the screen sharing device and the smart phone for use according to own needs.

Description

Technical Field

[0001] The utility model belongs to a screen sharing device, in particular to a screen sharing device circuit capable of USB master-slave switching. Background Art

[0002] Since the functions and pixels of the rear cameras of current smartphones are better than those of the front cameras, in order to meet the needs of smartphones using rear cameras for selfies or live broadcasts, screen-sharing devices that use mobile phone screen-sharing technology to assist smartphones in taking selfies or live broadcasts with rear cameras are gradually becoming popular among consumers.

[0003] Existing screen sharing devices include those that use USB host device mode for screen sharing and those that use USB slave device mode for screen sharing.

[0004] When the screen doubling device is connected in USB host mode, the screen doubling device is the master device and the smartphone is the slave device. The advantage of this type of screen doubling device is that it can be connected to the smartphone using an ordinary mobile phone data cable. However, this type of screen doubling device has a disadvantage. When the smartphone is in slave mode, the USB port of the smartphone can no longer be expanded to connect an external MIC to improve the sound quality of live or recorded video.

[0005] When the screen doubling device is connected in USB slave mode, the screen doubling device is the slave device and the smartphone is the master device. The advantage of this type of screen doubling device is that the smartphone is the master device and can connect an external MIC through the USB port to improve the sound quality of live or recorded videos. However, this type of screen doubling device has a disadvantage, as it requires an additional USB HUB with OTG function to connect the doubling device to the smartphone, which will undoubtedly increase the cost of use.

[0006] The above two screen sharing devices have only one connection mode, but the user's usage needs may change during use. Therefore, a screen sharing device that can switch between master and slave is needed so that the user can choose the connection mode according to his or her own needs. Utility Model Content

[0007] In order to solve the above problems, the purpose of the present invention is to provide a screen-sharing circuit capable of USB master-slave switching, which has a master-slave switching function so that users can choose to use the connection mode according to their own needs.

[0008] In order to achieve the above-mentioned purpose, the technical solution of the present utility model is as follows.

[0009] A screen-sharing device circuit capable of USB master-slave switching, characterized by comprising:

[0010] Display screen;

[0011] Connection interface;

[0012] A main processor that processes the data signals from the connection interface on the same screen;

[0013] The MCU performs master-slave switching on the main processor controlled by analyzing the voltage and signal of the connection interface. The MCU is connected to the main processor, the display screen is connected to the main processor, and both the MCU and the main processor are connected to the connection interface.

[0014] In this circuit, the MCU analyzes the voltage and signal of the connection interface to detect the data cable connected to the connection interface. When it detects that a universal USB data cable is inserted, it controls the main processor to switch to direct connection mode (the screen-matching device is the master device, and the mobile phone is the slave device); when it detects that a data cable processed by an OTG device is inserted, it switches the main processor to OTG mode (the screen-matching device is the slave device, and the mobile phone is the master device); that is, through the above-mentioned master-slave switching function, this circuit allows users to choose the connection mode between the screen-matching device and the smartphone according to their own needs.

[0015] Furthermore, the circuit also includes a WIFI antenna and a Bluetooth antenna, the WIFI antenna is connected to the main processor, and the Bluetooth antenna is connected to the MCU. Based on the settings of the WIFI antenna and Bluetooth antenna, the circuit can also realize wireless connection and screen projection between the screen sharing device and the smartphone; specifically, when the MCU detects that there is no data cable plugged into the connection interface, it switches the main processor to WIFI mode (i.e., the screen sharing device is wirelessly connected to the smartphone via the WIFI antenna and Bluetooth antenna).

[0016] Furthermore, the circuit also includes a power supply module for power supply, and the power supply module is connected to the connection interface, MCU, and display screen.

[0017] Furthermore, the power module includes:

[0018] A power interface for connecting an external power source to power the circuit;

[0019] A power module for directly powering the circuit;

[0020] A power supply switching control module is used to switch the power supply module to power the circuit when the external power supply is not supplying power. The power interface and the power interface are both connected to the power supply switching control module, and the power supply switching control module is connected to the connection interface, MCU, and display screen.

[0021] Furthermore, the power supply module includes a power supply circuit and a current limiting resistor, and the power supply circuit is connected to the power supply switching control module via the current limiting resistor.

[0022] Furthermore, the circuit also includes a resistance-capacitance voltage matching module, and the MCU is connected to the connection interface through the resistance-capacitance voltage matching module.

[0023] Furthermore, the display screen is an LCD screen.

[0024] Furthermore, the connection interface is a TYPEC data port.

[0025] Furthermore, the MCU is an AC6321A4 chip.

[0026] Furthermore, the main processor is a Haiqi B100 chip.

[0027] The beneficial effect of the present invention is that, in the circuit, the MCU analyzes the voltage and signal of the connection interface to detect the data line connected to the connection interface, and when it detects that a universal USB data line is inserted, it controls the main processor to switch to direct connection mode (the screen-matching device is the master device, and the mobile phone is the slave device); when it detects that a data line processed by an OTG device is inserted, the main processor is switched to OTG mode (the screen-matching device is the slave device, and the mobile phone is the master device); that is, the circuit uses the above-mentioned master-slave switching function to allow users to choose the connection mode between the screen-matching device and the smart phone according to their own needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a circuit principle diagram of the utility model.

[0029] Figure 2 yes Figure 1 Part A of the circuit schematic.

[0030] Figure 3 yes Figure 1 Part B of the circuit schematic.

[0031] Figure 4 yes Figure 1 Part C of the circuit schematic. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] See also Figure 1-4 This embodiment provides a USB master-slave switchable screen-sharing circuit, comprising:

[0034] Display screen;

[0035] Connect interface J2;

[0036] For the main processor 2 for same-screen processing of the MIRACAST protocol or AIRCAST protocol in the data signal of the connection interface J2, the circuit of the main processor 2 adopts a mature integrated circuit provided by the manufacturer;

[0037] The voltage and signal of the connection interface J2 are analyzed to control the main processor 2 for master-slave switching. The MCU1 is connected to the main processor 2, the display screen is connected to the main processor 2, and both the MCU1 and the main processor 2 are connected to the connection interface J2.

[0038] In this embodiment, the circuit further includes a WIFI antenna and a Bluetooth antenna. The WIFI antenna is connected to the main processor 2 , and the Bluetooth antenna is connected to the MCU1 .

[0039] In this embodiment, the circuit further includes a power supply module 4 for supplying power. The power supply module 4 is connected to the connection interface J2, the MCU1, and the display screen.

[0040] In this embodiment, the power module 4 includes:

[0041] Power interface J1 for connecting an external power supply to the circuit;

[0042] A power supply module 4 for directly supplying power to the circuit;

[0043] The power supply switching control module 5 is used to switch the power supply module 4 to power the circuit when the external power supply is not supplying power. The power supply interface J1 and the power supply interface J1 are both connected to the power supply switching control module 5, and the power supply switching control module 5 is connected to the connection interface J2, MCU1, and the display screen.

[0044] Specifically, the power supply switching control module 5 includes

[0045] In this embodiment, the power module 4 includes a power circuit and a current limiting resistor R9, and the power circuit is connected to the power supply switching control module 5 via the current limiting resistor R9. The power circuit includes a battery and a charging IC.

[0046] In this embodiment, the circuit further includes a RC voltage matching module 3, and the MCU1 is connected to the connection interface J2 via the RC voltage matching module 3. The RC voltage matching module 3 specifically includes a resistor R26, a resistor R90, a resistor R27, and a resistor R91.

[0047] In this embodiment, the display screen is an LCD screen.

[0048] In this embodiment, the connection interface J2 is a TYPEC data port.

[0049] In this embodiment, MCU1 is an AC6321A4 chip.

[0050] In this embodiment, the main processor 2 is a Haiqi B100 chip.

[0051] The following describes the working principle of the automatic switching between external power supply and power supply:

[0052] When J1 is plugged into an external power supply, 5V is input to 5V_IN, MOS transistor Q1 is turned off, and diode D1, resistor R3, MOS transistor Q3, and MOS transistor Q2 are turned on. MOS transistor Q2 provides power to the device. When J1 is disconnected from the external power supply, 0V is input to 5V_IN, MOS transistor Q1 is turned on, diode D1, resistor R3, MOS transistor Q3, and MOS transistor Q2 are turned off, and MOS transistor Q1 provides power to the device.

[0053] In direct connection mode, the automatic switching of external power supply and battery power supply has the same function. At the same time, the VBUS power supply on the mobile phone side must be controlled. The control timing and protocol requirements can refer to the standard protocol of TYPEC. The hard circuit is implemented as follows: MCU1 outputs EN_VOUT signal to control MOS tube Q7 and MOS tube Q6 to turn on, thereby controlling the VIN_3 voltage output to 5V_OUT to TYPEC connector J2.

[0054] When powered by battery alone, the voltage of VIN_3 is provided by the 4.8V power supply (4V8) -> resistor R9 (VIN3). Resistor R9 mainly acts as a current limiter to prevent the battery on the display from being consumed excessively due to 5V_OUT charging the mobile phone.

[0055] When J1 is plugged into an external power supply, the voltage is supplied from J1 (5V_IN) to MOS transistor Q4 (VIN_3). MOS transistor Q4 prevents the voltage from VIN_3 from flowing back to 5V_IN when powered solely by the battery, and then back to the battery through MOS transistors Q2 and Q1, thereby generating ineffective, self-consumption current.

[0056] The on / off principle of MOS transistor Q4 is as follows: When J1 is plugged into an external power supply, 5V is input to 5V_IN, diode D1, resistor R3, MOS transistor Q5, and MOS transistor Q4 are turned on, and the VIN_3 voltage is provided by MOS transistor Q4. When J1 is disconnected from the external power supply, 0V is input to 5V_IN, diode D1, resistor R3, MOS transistor Q5, and MOS transistor Q4 are turned off, and the device is powered by the 4.8V power supply.

[0057] Finally, it should be noted that the voltage value of the 4.8V power supply is actually 5V. 4.8V is taken to be the lower limit of 5V, which slightly reduces the power consumption of the current limiting resistor R9. Resistors R5, R6, diodes D3, and D2 provide pull-up voltages for the G poles of MOS tubes Q2 and Q4 respectively. C1 is a filter capacitor.

[0058] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A USB master-slave switchable screen sharing circuit, characterized in that: include: Display screen; Connection interface; A main processor that processes the data signals from the connection interface on the same screen; The MCU performs master-slave switching on the main processor controlled by analyzing the voltage and signal of the connection interface. The MCU is connected to the main processor, the display screen is connected to the main processor, and both the MCU and the main processor are connected to the connection interface.

2. The USB master-slave switchable screen-sharing circuit according to claim 1, characterized in that: The circuit also includes a WIFI antenna and a Bluetooth antenna, wherein the WIFI antenna is connected to the main processor, and the Bluetooth antenna is connected to the MCU.

3. The USB master-slave switchable screen-sharing circuit according to claim 1, characterized in that: The circuit also includes a power supply module for power supply, and the power supply module is connected to the connection interface, the MCU, and the display screen.

4. The USB master-slave switchable screen-sharing circuit according to claim 3, characterized in that: The power module includes: A power interface for connecting an external power source to power the circuit; A power module for directly powering the circuit; A power supply switching control module is used to switch the power supply module to power the circuit when the external power supply is not supplying power. The power interface and the power interface are both connected to the power supply switching control module, and the power supply switching control module is connected to the connection interface, MCU, and display screen.

5. The USB master-slave switchable screen-sharing circuit according to claim 4, characterized in that: The power supply module includes a power supply circuit and a current limiting resistor, and the power supply circuit is connected to the power supply switching control module through the current limiting resistor.

6. The USB master-slave switchable screen-sharing circuit according to claim 1, characterized in that: The circuit also includes a resistance-capacitance voltage matching module, and the MCU is connected to the connection interface via the resistance-capacitance voltage matching module.

7. The USB master-slave switchable screen-sharing circuit according to claim 1, characterized in that: The display screen is an LCD screen.

8. The USB master-slave switchable screen-sharing circuit according to claim 1, characterized in that: The connection interface is a TYPEC data port.

9. The USB master-slave switchable screen-sharing circuit according to claim 1, characterized in that: The MCU is the AC6321A4 chip.

10. The USB master-slave switchable screen-sharing circuit according to claim 1, characterized in that: The main processor is the Haiqi B100 chip.

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