WO2018113128A1

WO2018113128A1 - Method for recognizing plug-and-play device, and electronic device

Info

Publication number: WO2018113128A1
Application number: PCT/CN2017/078625
Authority: WO
Inventors: 王朝; 马雷; 罗伟
Original assignee: 华为技术有限公司
Priority date: 2016-12-20
Filing date: 2017-03-29
Publication date: 2018-06-28
Also published as: CN108475245B; CN108475245A

Abstract

The embodiments of the present invention relate to a method for recognizing a plug-and-play device, and an electronic device. In this method, an electronic device determines a device type of an external device according to a working state of a power bus pin of a universal serial bus (USB) connector. When the device type is a charging-type device, the electronic device enters a charging mode. Alternatively, when the device type is a non-charging-type device, the electronic device acquires a first voltage value of an ID pin of the USB connector. If the first voltage value is greater than a first voltage threshold and is less than a second voltage threshold, the electronic device turns off a plug-and-play OTG function, and the first voltage threshold is less than the second voltage threshold. The method improves the accuracy of identifying the electronic device entering an OTG mode without adding a device, reduces costs, and at the same time, avoids the power consumption generated by frequently awakening the electronic device due to voltage fluctuations of a GPIO port in a non-OTG mode, and prevents the OTG mode from being entered by mistake.

Description

Plug-and-play device identification method and electronic device

The present application claims priority to Chinese Patent Application, filed on Dec. 20, 2016, to the Chinese Patent Office, Application No. 201611186660.9, entitled "A Method and Apparatus for Implementing OTG Functions on Electronic Devices", the entire contents of which are incorporated by reference. Combined in this application. For the sake of brevity, the entire contents are not repeated in the original application.

Technical field

The embodiments of the present invention relate to the field of electronic device data interface technologies, and in particular, to a method and an electronic device for identifying a plug-and-play device.

Background technique

On The Go (OTG) technology enables the connection of various electronic devices to exchange data without a host.

Electronic devices, such as mobile devices, can be connected directly or indirectly to the USB connector of the OTG device via a tiny 5-pin (micro 5pin) or 10-pin universal serial bus (USB) connector. When the general-purpose input/output (GPIO) interface of the electronic device detects that the identity (ID) pin of the USB connector outputs a low level, the GPIO interface generates an interrupt response to the central processor of the mobile device. (Central Processing Unit, CPU), to wake up the CPU, and instruct the CPU to have OTG device access, so that the mobile device enters the OTG mode for data transmission.

FIG. 1 is a schematic structural diagram of an electronic device connected to an OTG device. As shown in FIG. 1, the electronic device is connected to the OTG device through a USB integrated circuit (IC) device, that is, the electronic device is indirectly connected to the OTG device.

The USB IC device recognizes that the ID pin is pulled low by detecting the resistance value of the ID pin of the OTG device's USB connector to the ground, and the USB IC device generates an INT interrupt response to the CPU or power management unit of the electronic device. Management unit (PMU) to indicate that an OTG device is connected, and the electronic device enters the OTG mode. The USB IC device reads the corresponding address inside the inter-integrated circuit (I2C) register to obtain the data to be transmitted, and at the same time, the USB IC device recognizes whether the resistance between the USB ID interface and the ground satisfies the OTG function. The preset threshold value, if satisfied, the electronic device and the OTG device perform data transmission.

However, although the connection structure between the above devices can accurately identify the connection to the OTG device, it is necessary to add a USB IC device, which is costly.

Summary of the invention

The embodiment of the invention provides a method for identifying a plug-and-play device and an electronic device. On the basis of not adding the device, the accuracy of identifying the electronic device into the OTG mode is improved, and the cost is reduced, and in the non-OTG mode. Turn off the Plug and Play OTG function to reduce power consumption.

In a first aspect, a method for identifying a plug and play device is provided, and the method may include:

The electronic device determines the device type of the external device according to the working state of the power bus pin of the universal serial bus USB connector. When the device type is a charging device, the electronic device enters a charging mode. When the device type is a non-charging device, the electronic device acquires a first voltage value of the ID pin of the USB connector through an analog to digital converter (ADC) interface. The first voltage value is a voltage value between the ID pin and the ground. The electronic device avoids the mutual exclusion of the OTG function inserted into the OTG device and the charging process by first checking whether a charging device is inserted. If the first voltage value is greater than the first voltage threshold and less than the second voltage threshold, the electronic device turns off the plug-and-play OTG function and stops responding to an interrupt generated by the GPIO interface, the first voltage threshold being less than the second voltage threshold. The method improves the accuracy of identifying the electronic device into the OTG mode, reduces the cost, and avoids the voltage fluctuation of the GPIO port in the non-OTG mode to frequently wake up the power consumption generated by the electronic device and prevent the error on the basis of not adding the device. Enter the OTG mode.

In an optional implementation, the method further includes: if the first voltage value is greater than the second voltage threshold, after the electronic device is initialized, detecting the working state of the power bus BUS pin again, and re-determining the device of the external device Types of. When the device type is a non-charging device, the second voltage value of the ID pin is obtained through the ADC interface. When the second voltage value is less than the first voltage threshold, the electronic device determines that the external device is a plug and play OTG device.

In an optional implementation, the method further includes: if the first voltage value is less than the first voltage threshold, the electronic device determines that the external device is an OTG device.

In an alternative implementation, the first voltage threshold is the maximum voltage value of the ID pin. The value can be expressed as: VCC*((r0+R)/(R1+R+r0)), where VCC is the access voltage of the electronic device, and r0 is the resistance of the wire in the connection between the OTG device and the electronic device, R1 is Pull-up resistor, R is the grounding resistance of the ID pin.

In a second aspect, an electronic device is provided having the function of implementing the behavior of the electronic device in the actual method described above. This function can be implemented in hardware or in hardware by executing the corresponding software. The hardware or software includes one or more modules corresponding to the functions described above.

In a third aspect, another electronic device is provided, the electronic device comprising: a memory and a processor. The memory is used to store program instructions, and the processor is configured to determine the device type of the external device according to the working state of the power bus pin of the USB connector. The processor is further configured to enter a charging mode when the device type is a charging device; or, when the device type is a non-charging device, obtain a first voltage value of the ID pin of the USB connector. If the first voltage value is greater than the first voltage threshold and less than the second voltage threshold, the processor turns off the OTG function, the first voltage threshold being less than the second voltage threshold.

In an optional implementation, if the first voltage value is greater than the second voltage threshold, the processor determines the device type of the external device again after being initialized. When the device type is a non-charging type device, the second voltage value of the ID pin is obtained. When the second voltage value is less than the first voltage threshold, the processor determines that the external device is an OTG device.

In an optional implementation, the processor is further configured to determine that the external device is an OTG device if the first voltage value is less than the first voltage threshold.

In an alternative implementation, the first voltage threshold is the maximum voltage value of the ID pin.

In still another aspect, a computer storage medium is provided for storing computer software instructions for use in the electronic device described above, including a program designed to perform the above aspects.

DRAWINGS

1 is a schematic structural diagram of an electronic device connected to an OTG device;

2 is a schematic structural diagram of an electronic device according to an embodiment of the present invention;

3 is a schematic circuit diagram of an electronic device connected to an external device according to an embodiment of the present invention;

4 is a flowchart of a method for identifying a plug and play device according to an embodiment of the present invention;

FIG. 5 is a flowchart of another method for identifying a plug and play device according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure;

FIG. 7 is a schematic structural diagram of another electronic device according to an embodiment of the present invention.

detailed description

The technical solutions of the present application are further described in detail below through the accompanying drawings and embodiments.

The identification method of the OTG function of the present application can be applied to the electronic device shown in FIG. 2. The electronic device and the external device are connected via a USB connector.

The electronic device may be a digital camera, a video camera, or a mobile phone. The external device can be a printer, a USB flash drive or a memory card.

As shown in FIG. 2, the electronic device can include a processor and a USB connector. The processor can include an analog to digital converter (ADC) interface and a GPIO interface.

The ADC interface and the GPIO interface are respectively connected to the ID pin of the USB connector.

ADC interface for reading the voltage value of the ID pin of the USB connector.

The GPIO interface is used to obtain the level status of the ID pin of the USB connector, such as a high level (as indicated by 1) or a low level (as indicated by 0), and an interrupt response is sent to the electronic device.

When the electronic device is not connected to an external device, the ID pin of the USB connector is left floating, and the level of the ID pin is high. When the electronic device is connected to the external device, the level of the ID pin changes to a low level, and the electronic device identifies whether the external device is an OTG device according to the voltage value read by the ADC interface.

For example, when an electronic device is connected to an external device and the level on the ID pin acquired by the GPIO interface is low, the ADC interface reads the voltage value on the ID pin and transmits the voltage value to the processor of the electronic device. (such as CPU). When the voltage value read by the ADC interface is less than the preset threshold, the electronic device recognizes that the external device is an OTG device; when the voltage value read by the ADC interface is greater than a preset threshold, the electronic device identifies the external device as a non-OTG device.

If the external device is an OTG device, the GPIO sends an interrupt response to the electronic device to wake up the processor of the electronic device, such as a CPU, and the electronic device enters the OTG mode to perform data transmission with the external device.

If the external device is not an OTG device, the GPIO does not send an interrupt response to the electronic device, that is, the OTG interrupt response is turned off.

It can be seen that the above method of the present application can ensure accurate identification of whether to enter the OTG mode without adding equipment, thereby reducing the cost.

Corresponding to the structural diagram of FIG. 2, the circuit connection structure of the electronic device and the external device can be as shown in FIG. 3. In FIG. 3, the USB connector is a 10-pin USB connector, wherein VBUS is a power bus pin. D+ and D- are data pins, GND is a ground pin, and S1-S5 are fixed pins for more securely attaching the USB connector to the soldering plate. The ID pin of the USB connector is connected to the second end of the resistor R2, and the first end of the resistor R2 is connected to the electronic device The GPIO interface is connected to wake up the CPU. The ID pin of the USB connector is connected to the second end of the resistor R3, and the first end of the resistor R3 is connected to the ADC interface of the electronic device for transmitting the voltage value of the ID pin to the CPU. VCC is the external voltage of the electronic device, and R1 is the pull-up resistor. The first end of the pull-up resistor R1 is connected to VCC, and the second end of the pull-up resistor R1 is connected to the second end of the resistor R2 at an intersection M. The first end of the coupling capacitor C1 is grounded, and the second end of the coupling capacitor C1 is connected to the intersection M. Data signals can be transmitted between the external device and the USB connector.

Among them, the user inserts and removes an external device for a long time, causing electrostatic discharge (ESD) or surge phenomenon generated by the ID pin, which may cause damage to the electronic device. In FIG. 3, the resistor R1, the resistor R2 and the capacitor C1 are connected in parallel to form an RC filter, which can solve the problem of damage of the electronic device due to the above electrostatic discharge or surge phenomenon. Among them, the resistance of R2 can be 2kΩ, and the resistance of R3 can be 10kΩ.

Optionally, when the electronic device has an external device, the grounding resistor R (ie, the resistance between the ID pin and the GND pin) exists on the ID pin, and the CPU of the electronic device can obtain the voltage of the grounding resistor R through the ADC interface. value.

FIG. 4 is a flowchart of a method for identifying a plug and play device according to an embodiment of the present invention. As shown in FIG. 4, the method may include:

Step 410: The electronic device detects a level state on the ID pin of the USB connector, and determines whether it is connected to the external device.

After the electronic device is turned on, it is determined whether the electronic device is connected to the external device according to the level state on the ID pin of the USB connector. For example, when the ID pin of the USB connector has a low level, the electronic device determines to connect with the external device, and conversely, the electronic device determines that the external device is not connected.

Step 420: The electronic device determines the device type of the external device according to the working state of the power bus pin of the USB connector.

In the case where the ID pin of the USB connector is low (that is, the electronic device is connected to an external device), the USB connector of the electronic device detects the working state of the power bus (VBUS) pin (or whether there is an external voltage), Determine the device type of the external device. The presence of an external voltage on the VBUS pin means that the VBUS pin has an input voltage.

When there is an external voltage on the VBUS pin, the electronic device determines that the external device is a charging device, and the electronic device enters the charging mode, and the interrupt response of the GPIO interface is turned off.

When the VBUS pin does not have an external voltage (that is, the external device is a non-charging device), the electronic device acquires a first voltage value of the ID pin (ie, a first voltage value of the grounding resistance R) through the ADC interface, and the first voltage value It is used to identify the external connection of the USB connector of the electronic device (for example, the connected external device is a non-charging device or is not connected to an external device). Among them, when the VBUS pin has an input voltage, there is an external voltage on the VBUS pin. In FIG. 3, the first voltage value is a voltage value of the grounding resistance R.

It can be seen that the electronic device avoids the mutual exclusion of the OTG function and the charging function of the OTG device by first checking whether a charging device is inserted.

Step 430: The electronic device identifies, according to a comparison result of the first voltage value of the ID pin and the first voltage threshold and the second voltage threshold, whether the electronic device enters the OTG mode.

Referring to FIG. 3, the resistor R1 is connected in series with the grounding resistor R, that is, the grounding resistor R and the resistor R1 are divided, and the voltage value of the grounding resistor R can be expressed as VCC*(R/(R1+R)).

Optionally, after the OTG device is inserted into the electronic device, considering the certain resistance r0 that the wire in the connection between the OTG device and the electronic device exists, the maximum resistance Rm of the grounding resistance is (r0+R). The maximum resistance Rm corresponds to The voltage value is a first voltage threshold, which can be expressed as VCC*((r0+R)/(R1+R+r0)), ie the first voltage threshold is the maximum voltage value on the ID pin.

Optionally, the second voltage threshold is a preset voltage threshold of the electronic device. The value of the second voltage threshold is between a voltage value between the maximum voltage safety threshold of the electronic device and the minimum voltage safety threshold. For example, VCC is 3V, the maximum voltage safety threshold of the electronic device is 3*(3/4)=2.25V, and the minimum voltage safety threshold is 3*(1/4)=0.75V. That is, the second voltage threshold is greater than 0.75V and less than 2.25V, as the second voltage threshold may be 1.25V.

It should be noted that the first voltage threshold is less than the minimum voltage safety threshold of the electronic device, that is, the first voltage threshold is less than the second voltage threshold, for example, the first voltage threshold may be 0.15V, and the second voltage threshold may be 1.25V.

After the electronic device acquires the first voltage value of the grounding resistance R through the ADC interface, the electronic device compares the first voltage value with the first voltage threshold and the second voltage threshold, respectively.

When the first voltage value is less than the first voltage threshold, the electronic device determines that the external device is an OTG device, turns on the GPIO interrupt response, and the electronic device enters the OTG mode to perform data transmission with the OTG device.

When the first voltage value is greater than the first voltage threshold and less than the second voltage threshold, the electronic device actively turns off the GPIO interrupt response to avoid the GPIO port voltage fluctuation to frequently wake up the power consumption generated by the electronic device, and prevent the erroneous entry into the OTG mode. . The GPIO port voltage fluctuation may be caused by the electronic device user being used for a long time, causing the USB interface to be dirty, and the GPIO port voltage fluctuation occurs.

When the first voltage value is greater than the second voltage threshold, the interrupt response of the GPIO is turned on, and the electronic device determines that there is no external device at this time, that is, the electronic device is in the standby state.

Under this condition, the electronic device initializes the processor and detects whether an external device is inserted, and turns on the interrupt response of the GPIO.

If the electronic device has an external device inserted, the electronic device first determines whether the external device is a charging device.

If the external device is a charging device, the electronic device enters the charging mode and turns off the GPIO interrupt response.

If the external device is a non-charging device and a low level is recognized on the GPIO interface, the electronic device reads the second voltage value of the grounding resistance R through the ADC interface, and when the second voltage value is less than the first voltage threshold, the electronic device Enter the OTG mode.

In an example, as shown in FIG. 5, the electronic device is used as a mobile phone, and the OTG device is a USB disk as an example for detailed description.

After the mobile phone is powered on, step 510 is executed, and the processor in the mobile phone detects that the ID pin is low level through the GPIO interface, and determines to access the external device.

Step 520: The processor in the mobile phone detects whether an external voltage exists in the BUS pin;

If yes, go to step 530 and the mobile phone enters the charging mode.

If not, executing step 540, the processor in the mobile phone acquires the voltage value V1 of the ID pin through the ADC interface.

Step 550: The processor in the mobile phone compares V1 with the first voltage threshold and the preset second voltage threshold respectively;

Step 560: V1 is smaller than the first voltage threshold, and the processor in the mobile phone determines that the external device is a U disk. At this time, the interrupt response of the GPIO is turned on, and the mobile phone enters the OTG mode to perform data transmission with the U disk.

Step 570, V1 is greater than the first voltage threshold, and is less than the second voltage threshold, and the processor in the mobile phone actively closes GPIO interrupt response.

Step 580, V1 is greater than the second voltage threshold, and the processor in the mobile phone turns on the interrupt response of the GPIO, and is in a standby state.

Step 590, the processor in the mobile phone initializes, and after the GPIO interface recognizes that there is a low level on the ID pin, it is determined whether the external voltage exists in the BUS pin;

If yes, go to step 530 and the mobile phone enters the charging mode.

If not, step 600 is performed, and the processor in the mobile phone acquires the voltage value V2 on the ID pin through the ADC interface.

If V2 is less than the first voltage threshold, step 610 is executed, and the processor in the mobile phone determines that the external device is a USB flash drive. At this time, the interrupt response of the GPIO is turned on, and the mobile phone enters the OTG mode to perform data transmission with the USB flash drive.

If V2 is greater than the first voltage threshold, step 620 is executed, the processor in the mobile phone turns on the GPIO interrupt response, is in the standby state, and proceeds to step 590.

The embodiment of the present invention further provides another electronic device, corresponding to the foregoing method for identifying the plug and play device. As shown in FIG. 6, the electronic device can include a processing unit 630.

The processing unit 630 is configured to determine, according to an operating state of a power bus pin of the USB connector of the device, a device type of the external device;

The processing unit 630 is further configured to enter a charging mode when the device type is a charging device; or, when the device type is a non-charging device, acquire a first voltage value of an ID pin of the USB connector.

If the first voltage value is greater than the first voltage threshold and less than the second voltage threshold, the processing unit 630 turns off the OTG function, the first voltage threshold being less than the second voltage threshold.

Optionally, if the first voltage value is greater than the second voltage threshold, the processing unit 630, after being initialized, detects an operating state of the power bus pin, and determines the device type of the external device again.

The processing unit is further configured to acquire a second voltage value of the ID pin when the device type is a non-charging type device according to an operating state of the power bus pin.

When the second voltage value is less than the first voltage threshold, the processing unit determines that the external device is an OTG device.

Optionally, the processing unit 630 is further configured to determine that the external device is an OTG device if the first voltage value is less than the first voltage threshold.

Optionally, the first voltage threshold is a maximum voltage value of the ID pin.

The functions of the functional units of the electronic device can be implemented by the steps of the electronic device in the foregoing embodiments. Therefore, the specific working process of the electronic device provided by the embodiment of the present invention is not described herein.

The embodiment of the present invention further provides another electronic device, corresponding to the foregoing method for identifying the plug and play device. As shown in FIG. 7, the electronic device can include a processor 710, a memory 720, an ADC interface 730, a GPIO interface 740, and a USB connector 750.

The processor 710 can include a GPIO module 711 and an ADC 712.

The processor 710 can be a central processing unit (CPU), or a combination of a CPU and a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. On The PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a general array logic (GAL), or any combination thereof.

The memory 720 may include a volatile memory such as a random-access memory (RAM); the memory 720 may also include a non-volatile memory such as a read-only memory (read) -only memory, ROM), flash memory, hard disk drive (HDD) or solid-state drive (SSD).

Memory 720 can also include a combination of the above types of memory. The memory 720 stores the program code and transmits the stored program code to the processor 710.

The processor 710 is configured to determine a device type of the external device according to an operating state of the power bus pin of the USB connector 750 of the device.

The processor 710 is further configured to enter a charging mode when the device type is a charging device; or, when the device type is a non-charging device, acquire the first voltage value of the ID pin of the USB connector 750 through the ADC interface 730. . If the first voltage value is greater than the first voltage threshold and less than the second voltage threshold, the processor 710 turns off the interrupt response of the GPIO interface 740 in the GPIO module 711, that is, turns off the OTG function, and the first voltage threshold is less than the second voltage threshold.

Optionally, if the first voltage value is greater than the second voltage threshold, the ADC 712 in the processor 710 is initialized, detects the working state of the power bus pin of the USB connector 750, and determines the device type of the external device again;

The processor 710 is further configured to acquire a second voltage value of the ID pin through the ADC interface 730 when the device type is a non-charging type device according to an operating state of the power bus pin. When the second voltage value is less than the first voltage threshold, the processor 710 determines that the external device is an OTG device.

Optionally, the processor 710 is further configured to determine that the external device is an OTG device if the first voltage value is less than the first voltage threshold.

For the implementation and the beneficial effects of the various devices of the electronic device in the above embodiments, reference may be made to the method embodiments and the beneficial effects shown in FIG. 4, and thus details are not described herein.

A person skilled in the art should further appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both, in order to clearly illustrate hardware and software. Interchangeability, the composition and steps of the various examples have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods to implement the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present application.

It will be understood by those skilled in the art that all or part of the steps of implementing the above embodiments may be performed by a program, and the program may be stored in a computer readable storage medium, which is non-transitory ( Non-transitory medium, such as random access memory, read only memory, flash memory, hard disk, solid state disk, magnetic tape, floppy disk, optical disc, and any combination thereof.

The foregoing is only a preferred embodiment of the present application, but the scope of protection of the present application is not limited thereto. It is to be understood that those skilled in the art are susceptible to variations or substitutions within the scope of the present disclosure. Therefore, the scope of protection of the present application should be determined by the scope of protection of the claims.

Claims

A method for identifying a plug and play device, the method comprising:

The electronic device determines the device type of the external device according to the working state of the power bus pin of the universal serial bus USB connector;

When the device type is a charging device, the electronic device enters a charging mode;

When the device type is a non-charging type device, the electronic device acquires a first voltage value of an ID pin of the USB connector;

If the first voltage value is greater than the first voltage threshold and less than the second voltage threshold, the electronic device turns off the plug and play OTG function, and the first voltage threshold is less than the second voltage threshold.
The method of claim 1 further comprising:

If the first voltage value is greater than the second voltage threshold, the electronic device determines the device type of the external device again after being initialized;

When the device type is a non-charging type device, the electronic device acquires a second voltage value of the ID pin;

When the second voltage value is less than the first voltage threshold, the electronic device determines that the external device is an OTG device.
The method of claim 1 further comprising:

And if the first voltage value is less than the first voltage threshold, the electronic device determines that the external device is an OTG device.
The method according to any one of claims 1 to 3, wherein the first voltage threshold is a maximum voltage value of the ID pin.
An electronic device, comprising: a processing unit,

The processing unit is configured to determine a device type of the external device according to an operating state of the power bus pin of the USB connector;

The processing unit is further configured to: when the device type is a charging device, enter a charging mode; when the device type is a non-charging device, acquire a first voltage value of an ID pin of the USB connector. ;

If the first voltage value is greater than the first voltage threshold and less than the second voltage threshold, the processing unit turns off the OTG function, the first voltage threshold being less than the second voltage threshold.
The device according to claim 5, characterized in that

If the first voltage value is greater than the second voltage threshold, the processing unit determines the device type of the external device again after being initialized;

The processing unit is further configured to acquire a second voltage value of the ID pin when the device type is a non-charging device;

When the second voltage value is less than the first voltage threshold, the processing unit determines that the external device is an OTG device.
The device according to claim 5, wherein the processing unit is further configured to determine that the external device is an OTG device if the first voltage value is less than the first voltage threshold.
The method of any of claims 5-7, wherein the first voltage threshold is a maximum voltage value of the ID pin.
An electronic device, comprising:

a memory for storing program instructions;

a processor for calling a program instruction stored in the memory to perform the following operations:

Determining the device type of the external device according to the working state of the power bus pin of the USB connector;

When the device type is a charging device, enter a charging mode;

Obtaining a first voltage value of an ID pin of the USB connector when the device type is a non-charging type device;

If the first voltage value is greater than the first voltage threshold and less than the second voltage threshold, the processor turns off the OTG function, the first voltage threshold being less than the second voltage threshold.
The device according to claim 9, wherein the processor is further configured to:

If the first voltage value is greater than the second voltage threshold, the processor determines the device type of the external device again after being initialized;

Obtaining a second voltage value of the ID pin when the device type is a non-charging type device;

When the second voltage value is less than the first voltage threshold, the processor determines that the external device is an OTG device.
The device according to claim 9, wherein the processor is further configured to:

And if the first voltage value is less than the first voltage threshold, determining that the external device is an OTG device.
The method of any of claims 9-11, wherein the first voltage threshold is a maximum voltage value of the ID pin.