WO2020238704A1

WO2020238704A1 - Method for multiplexing earphone seat and usb otg function

Info

Publication number: WO2020238704A1
Application number: PCT/CN2020/091116
Authority: WO
Inventors: 陈斯伟; 张坤
Original assignee: 晶晨半导体(上海)股份有限公司
Priority date: 2019-05-28
Filing date: 2020-05-19
Publication date: 2020-12-03
Also published as: CN110312180A

Abstract

The present invention relates to the technical field of OTG functions, in particular relates to a method for multiplexing an earphone seat and a USB OTG function. The method comprises: step S1, providing a multiplexing circuit, wherein the multiplexing circuit is respectively connected to an earphone seat and a control chip; and step S2, using the control chip to detect a level state of the earphone seat, and determining, by means of the multiplexing circuit, an external device which is inserted into the earphone seat. The technical solution of the present invention has the beneficial effects that the level state of the earphone seat is detected by using the control chip, and the external device which is inserted into the earphone seat is determined by means of the multiplexing circuit and can be respectively in communication connection with an earphone wire, a USB host device and a USB external device, such that multiplexing of an earphone function and an OTG function is realized, the circuit structure is simple, debugging performed by a software engineer is facilitated, and popularization is facilitated.

Description

A method of using the headphone socket and USB OTG function multiplexing

Technical field

The present invention relates to the technical field of OTG functions, and in particular to a method for using an earphone socket and USB OTG function multiplexing.

Background technique

USB (Universal Serial Bus) is a data communication method, it is also a data bus, and it is one of the most complex buses. In terms of hardware, it is connected by a plug, with a plug on one side and a receptacle on the other. For example, a socket on a computer is a female connector, and a USB device uses a male connector to connect to the computer. There are currently three types of USB hardware interfaces. The type used on ordinary computers is called Type; the original interface used in Nokia's feature phone era is Mini USB; and the current Micro USB used in Android phones.

USB OTG is the abbreviation of USB On-The-Go, which is a technology developed in recent years. On The Go, this is a form introduced in USB 2.0, and a new concept called Host Negotiation Protocol (Host Negotiation Protocol) is proposed, which allows two devices to negotiate who will be the Host. The OTG controller can be used as a host or a device. The role of the controller is generally determined by the USB ID level.

Since the design and appearance of smart audio products has been cancelled, the USB socket is reserved only for the earphone holder, which cannot realize the USB software burning, and the USB OTG function cannot be used during debugging. The industry's approach is to increase the miniUSB or mircoUSB interface, so the use cost is high, not to promote.

Summary of the invention

In view of the above-mentioned problems existing in the prior art, a method for multiplexing the functions of a headset and USB OTG is provided.

The specific technical solutions are as follows:

A method of using the headset socket and USB OTG function multiplexing, including:

Step S1: Provide a multiplexing circuit, and the multiplexing circuit is respectively connected to a headphone holder and a control chip;

Step S2: The control chip is used to detect the level state of the earphone holder, and the external device inserted into the earphone holder is determined through the multiplexing circuit.

Preferably, the multiplexing circuit further includes a switching unit, and the switching unit is respectively connected to the control chip and the earphone holder.

Preferably, the earphone holder includes:

A first pin connected to a first power terminal;

A second pin, connected to the right channel power terminal of the switching unit;

A third pin, connected to the first data pin of the control chip through a first resistor;

A fourth pin, connected to the left channel power terminal of the switching unit;

A fifth pin, connected to the ground terminal.

Preferably, the control chip includes:

A first data pin, which is used to implement the earphone detection pin;

A second data pin, used to implement USB audio switching pins;

A third data pin, used to realize the USB power pin;

One data acquisition pin, used to realize USB audio detection pin;

An ID pin, used to implement the USB ID pin;

A data negative signal pin, used to realize the USB OTG negative voltage pin;

One data positive signal pin, used to realize the USB OTG positive voltage pin;

An audio first output pin for realizing the left audio channel;

An audio second output pin, used to implement the audio right channel.

Preferably, the switching unit further includes:

A first switching pin connected to the second data pin;

A positive voltage terminal connected to the data positive signal pin;

A negative voltage terminal connected to the data negative signal pin;

A left channel pin, connected to the first audio output pin;

A right channel pin is connected to the second audio output pin.

Preferably, the multiplexing circuit includes:

A first power terminal, providing a first power voltage;

A second power terminal, providing a second power voltage;

A third power supply terminal, providing a third power supply voltage;

A fourth power supply terminal, providing a fourth power supply voltage;

A multiplexing unit, the multiplexing unit is respectively connected to the first voltage terminal, the second power terminal, the third power terminal, the fourth voltage terminal, the control chip and the earphone socket between.

Preferably, the multiplexing unit includes:

A triode, the emitter of the triode is connected to the third data pin, and the base of the triode is connected to the second voltage terminal through a second resistor;

A MOS tube, the gate of the MOS tube is connected to the collector of the triode through a third resistor, the source of the MOS tube is connected to the third power terminal, and the drain of the MOS tube is connected to the earphone The first pin of the socket;

A fourth resistor, connected between the fourth power terminal and the data acquisition pin through a diode;

A fifth resistor connected between the first pin of the earphone socket and the data collection pin;

A sixth resistor connected between the data acquisition pin and the ground terminal;

A seventh resistor, connected between the third power terminal and the collector of the triode;

An eighth resistor, connected between the ID pin and the emitter of the triode;

A ninth resistor connected between the first data pin and the second power terminal;

A tenth resistor, connected between the fourth pin of the earphone holder and the ground terminal;

A first capacitor connected between the first power terminal and the ground terminal;

A second capacitor is connected between the third power terminal and the gate of the MOS transistor.

Preferably, the step S2 includes:

Step S20: Judge whether the first data pin has a level change, and when the first data pin has a level change, go to step S21;

Step S21: Detect the voltage value of the data collection pin to determine the external device inserted into the earphone socket.

Preferably, in the step S21, when it is detected that the voltage value of the data collection pin is a first preset value, it is determined that the earphone socket is inserted into the earphone cable;

When detecting that the voltage value of the data collection pin is a second preset value, it is determined that the earphone holder is inserted into the USB host device;

When detecting that the voltage value of the data collection pin is a third preset value, it is determined that the earphone holder is inserted into a USB external device.

Preferably, the first preset value is 0.64V;

The second preset value is 0.80V;

The third preset value is 1.67V.

The beneficial effect of the technical solution of the present invention is to provide a method for multiplexing the functions of the earphone socket and USB OTG. The control chip is used to detect the level state of the earphone socket, and the external equipment inserted into the earphone socket is determined by the multiplexing circuit. Communicate and connect with earphone cable, USB host device, and USB external device to realize the multiplexing of earphone function and OTG function. The circuit structure is simple, which is convenient for software engineers to debug and promote.

Description of the drawings

With reference to the attached drawings, the embodiments of the present invention are described more fully. However, the attached drawings are only for illustration and illustration, and do not constitute a limitation on the scope of the present invention.

FIG. 1 is a flowchart of steps of a method for multiplexing the functions of an earphone holder and USB OTG according to an embodiment of the present invention;

2 is a flowchart of step S2 of the method for multiplexing the functions of an earphone holder and USB OTG according to an embodiment of the present invention;

Fig. 3 is a circuit connection diagram of the multiplexing circuit of the embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other if there is no conflict.

The present invention will be further described below with reference to the drawings and specific embodiments, but it is not a limitation of the present invention.

The present invention includes a method for multiplexing the functions of an earphone holder and USB OTG, including:

Step S1: Provide a multiplexing circuit, which is connected to an earphone jack AJ1 and a control chip SOC respectively;

Step S2: The control chip SOC is used to detect the level state of the earphone socket AJ1, and the external device inserted into the earphone socket AJ1 is determined through the multiplexing circuit.

Through the above-mentioned technical solution using the method of multiplexing the headphone holder and USB OTG function, combined with Figures 1 and 3, first identify the headphone function of the headphone holder AJ1 and the status recognition of the USB OTG function, and detect the headphone holder AJ1's status through the control chip SOC. The level status is combined with the multiplexing circuit to determine the voltage of the external device plugged into the headphone socket AJ1 to determine the device plugged into the headphone socket AJ1. The external devices can be detected as headphone cables, USB host devices and USB external devices.

Further, the control chip SOC can be used as a host device or an external device. The role of the control chip SOC is generally determined by the level of the USB ID. Among them, USB ID is the input signal, defined by the USB OTG protocol, and used to identify the default role of the device connected to the headset jack AJ1, that is, host mode or external device mode. The USB ID is pulled up by default and is in the state of an external device. If the headphone jack AJ1 needs to be in host mode, the control chip 3 will short USB_ID to the ground, that is, when the input is 0, it means that the headphone jack AJ1 is in host mode and communicates with USB external devices.

Further, the control chip SOC is used to detect the level status of the earphone holder AJ1, and the external device inserted into the earphone holder AJ1 is judged by the multiplexing circuit, which can communicate with the earphone cable, the USB host device, and the USB external device to realize the earphone function. Multiplexing with OTG functions, simple circuit structure, convenient for software engineers to debug and promote.

In a preferred embodiment, the multiplexing circuit further includes a switching unit U1, and the switching unit U1 is respectively connected to the control chip SOC and the earphone socket AJ1.

In the above technical solution, the switching unit U1 further includes:

A first switching pin ASEL, connected to the second data pin GPIOA_1;

A positive voltage terminal D+, connected to the data positive signal pin USB_DP;

A negative voltage terminal D-, connected to the data negative signal pin USB_DM;

One left channel pin L, connected to the first audio output pin AUDIO_L;

A right channel pin R is connected to the second audio output pin AUDIO_R.

Further, the control chip SOC is used to detect the level status of the earphone holder AJ1, and the external device inserted into the earphone holder AJ1 is determined by the multiplexing circuit, which can respectively communicate with the earphone cable, the USB host device, and the USB external device to realize the earphone function Multiplexing with OTG functions, simple circuit structure, convenient for software engineers to debug and promote.

In a preferred embodiment, the earphone holder AJ1 includes:

A first pin AJ10 is connected to a first power terminal S1;

A second pin AJ11 connected to the right channel power terminal DR+ of the switching unit U1;

A third pin AJ12 is connected to the first data pin GPIOA_0 of the control chip SOC through a first resistor R1;

A fourth pin AJ13, connected to the left channel power terminal DL- of the switching unit U1;

A fifth pin AJ14 is connected to the ground terminal GND.

Among them, the resistance value of the first resistor R1 is 1K ohms, and further, the control chip SOC is used to detect the level state of the earphone socket AJ1, and the external device inserted into the earphone socket AJ1 is judged by the multiplexing circuit, which can be connected to the earphone cable and USB The host device and the USB external device are connected for communication to realize the multiplexing of the earphone function and the OTG function. The circuit structure is simple, which is convenient for software engineers to debug and promote.

In a preferred embodiment, the control chip SOC includes:

A first data pin GPIOA_0, used to implement the headphone detection pin HP_DET;

A second data pin GPIOA_1, used to implement the USB audio switching pin USB_AUDIO_SW;

A third data pin GPIOA_2, used to implement the USB power pin USB_POWER;

A data acquisition pin SARADC_CH0, used to realize the USB audio detection pin USB_AUDIO_DET;

An ID pin USB_ID, used to implement the USB ID pin USB_ID;

A data negative signal pin USB_DM, used to realize the USB OTG negative voltage pin USB OTG_B_DM;

A data positive signal pin USB_DP, used to realize the USB OTG positive voltage pin USB OTG_B_DP;

An audio first output pin AUDIO_L, used to realize the left audio channel AUDIO_L;

An audio second output pin AUDIO_R is used to implement the audio right channel AUDIO_R.

Specifically, the first data pin GPIOA_0 is used to detect the level state of the headphone detection pin HP_DET. When the first data pin GPIOA_0 detects the level state of the headphone detection pin HP_DET from low to high, it means The headphone detection pin HP_DET has an external device inserted, and then the data acquisition pin SARADC_CH0 detects the voltage value of the USB audio detection pin USB_AUDIO_DET. When the voltage value of the USB audio detection pin USB_AUDIO_DET is 0.64V, it means that the headphone cable is inserted. When the voltage value of the USB audio detection pin USB_AUDIO_DET is 0.80V, it means that the USB host device is inserted, and when the voltage value of the USB audio detection pin USB_AUDIO_DET is 1.67V, it means that the USB external device is inserted.

In a preferred embodiment, the multiplexing circuit includes:

A first power terminal S1, providing a first power voltage VCC1;

A second power supply terminal S2, providing a second power supply voltage VCC2;

A third power terminal S3, providing a third power voltage VCC3;

A fourth power supply terminal S4, providing a fourth power supply voltage VCC4;

A multiplexing unit, the multiplexing unit is respectively connected between the first voltage terminal S1, the second power terminal S2, the third power terminal S3, the fourth voltage terminal S4, the control chip SOC and the earphone socket AJ1.

Among them, the first power supply voltage VCC1 is 5V, the second power supply voltage VCC2 is 3.3V, the third power supply voltage VCC3 is 5V, and the fourth power supply voltage VCC4 is 1.8V.

In the above technical solution, the multiplexing unit includes:

A triode Q1, the emitter of the triode Q1 is connected to the third data pin GPIOA_2, and the base of the triode Q1 is connected to the second voltage terminal S2 through a second resistor R2;

A MOS tube Q2, the gate of the MOS tube Q2 is connected to the collector of the transistor Q1 through a third resistor R3, the source of the MOS tube Q2 is connected to the third power terminal S3, and the drain of the MOS tube Q2 is connected to the first terminal of the earphone socket AJ1 Pin AJ10;

A fourth resistor R4 is connected between the fourth power terminal S4 and the data acquisition pin SARADC_CH0 through a diode D1;

A fifth resistor R5, connected between the first pin AJ10 of the earphone jack AJ1 and the data acquisition pin SARADC_CH0;

A sixth resistor R6, connected between the data acquisition pin SARADC_CH0 and the ground terminal GND;

A seventh resistor R7, connected between the third power terminal S3 and the collector of the transistor Q1;

An eighth resistor R8, connected between the ID pin USB_ID and the emitter of the transistor Q1;

A ninth resistor R9, connected between the first data pin GPIOA_0 and the second power terminal S2;

A tenth resistor R10, connected between the fourth pin AJ13 of the earphone jack AJ1 and the ground terminal GND;

A first capacitor C1 connected between the first power terminal S1 and the ground terminal GND;

A second capacitor C2 is connected between the third power terminal S3 and the gate of the MOS transistor Q1.

Specifically, the transistor Q1 is an NPN transistor, the MOS transistor Q2 is an N-type MOS transistor, the resistance value of the second resistor R2 is 47K ohms, the resistance value of the third resistor R3 is 100K ohms, and the resistance value of the fourth resistor R4 is 10K. Ohm, the resistance of the fifth resistor R5 is 20K ohms, the resistance of the sixth resistor R6 is 10K ohms, the resistance of the seventh resistor R7 is 47K ohms, the resistance of the eighth resistor R8 is 10K ohms, and the resistance of the ninth resistor R9 The resistance value of is 10K ohms, where the fourth resistor R4 and the sixth resistor R6 form a voltage divider resistor, connected to GPIOA_1 from the voltage divider node, the capacitance value of the first capacitor C1 is 22uF, and the capacitance value of the second capacitor C2 is 0.1uF .

In a preferred embodiment, as shown in FIG. 2, step S2 includes:

Step S20: Judge whether the first data pin GPIOA_0 has a level change, and when the first data pin GPIOA_0 has a level change, go to step S21;

Step S21: Detect the voltage value of the data collection pin SARADC_CH0 to determine the external device inserted into the earphone jack AJ1.

In the above technical solution, in step S21, when it is detected that the voltage value of the data collection pin SARADC_CH0 is a first preset value, it is determined that the earphone jack AJ1 is inserted into the earphone cable;

When detecting that the voltage value of the data acquisition pin SARADC_CH0 is a second preset value, it is determined that the earphone holder AJ1 is inserted into the USB host device;

When detecting that the voltage value of the data acquisition pin SARADC_CH0 is a third preset value, it is determined that the earphone jack AJ1 is inserted into the USB external device.

In the above technical solution, the first preset value is 0.64V;

The second preset value is 0.80V;

The third preset value is 1.67V.

Specifically, when the headphone socket AJ1 is in the headphone cable state, the third pin AJ3 of the headphone socket AJ1 is grounded when the headphone cable is inserted. At this time, the voltage value of the USB audio detection pin USB_AUDIO_DET is 0.64V, that is, 0.64V=[( 1.8-0.2)/(R4+R6//R5)]*(R6//R5), the third data pin GPIOA_2 outputs a high-level USB power pin USB_POWER to turn off the transistor Q1, and the MOS transistor Q2 is also turned off. The second When the data pin GPIOA_1 outputs a high-level USB audio switching pin USB_AUDIO_SW=1, the switching unit U1 switches to L, R road headphone output.

Further, when the headphone holder AJ1 is in the USB host device state, the third pin AJ3 of the headphone holder AJ1 is in a floating state when the USB host device is inserted. At this time, the voltage value of the USB audio detection pin USB_AUDIO_DET is 0.8V, that is, 0.8V= [(1.8-0.2)/(R4+R6)]*R6, the third data pin GPIOA_2 outputs a low-level USB power pin USB_POWER to turn on the transistor Q1, and the MOS tube Q2 also turns on the first power terminal S1 at this time. The first pin of the socket AJ1, which is the connected power pin USBOTG_B_5V, outputs a 5V voltage. The ID pin USB_ID pulls down the USB power pin USB_POWER through the eighth resistor R8 to input low level. At this time, the second data pin GPIOA_1 outputs low When the level USB audio switching pin USB_AUDIO_SW=0, the switching unit U1 switches to the USB road detection USB host peripheral.

Further, when the earphone holder AJ1 is in the USB host device state, when the USB external device is inserted, the third pin AJ3 of the earphone holder AJ1 is in an external 5V state. At this time, the voltage value of the USB audio detection pin USB_AUDIO_DET is 1.67V, which is 1.67 V=[5/(R4+R5)]*R6, the third data pin GPIOA_2 outputs a high-level USB power pin USB_POWER turns off the transistor Q1, and the MOS tube Q2 turns off the first power terminal S1 at this time. The first pin of AJ1, the connected power pin USBOTG_B_5V has no output, the ID pin USB_ID pulls up the USB power pin USB_POWER through the eighth resistor R8 to input high level, and the second data pin GPIOA_1 outputs low level USB audio When the switching pin USB_AUDIO_SW=0, the switching unit U1 switches to the USB road detection USB external device.

The above descriptions are only preferred embodiments of the present invention, and do not limit the implementation and protection scope of the present invention. For those skilled in the art, they should be able to realize that any equivalent made by using the description and illustrations of the present invention The solutions obtained by substitutions and obvious changes should all be included in the protection scope of the present invention.

Claims

A method for using a headset socket and USB OTG function multiplexing, which is characterized in that it includes:

Step S1: Provide a multiplexing circuit, and the multiplexing circuit is respectively connected to an earphone holder and a control chip;

Step S2: Use the control chip to detect the level state of the earphone holder, and determine the external device inserted into the earphone holder through the multiplexing circuit.
The method for multiplexing the functions of an earphone socket and USB OTG according to claim 1, wherein the multiplexing circuit further comprises a switching unit, and the switching unit is respectively connected to the control chip and the earphone socket.
The method for using the earphone socket and USB OTG function multiplexing according to claim 2, wherein the earphone socket comprises:

A first pin connected to a first power terminal;

A second pin connected to the right channel power terminal of the switching unit;

A third pin connected to the first data pin of the control chip through a first resistor;

A fourth pin connected to the left channel power terminal of the switching unit;

A fifth pin, connected to the ground terminal.
The method for using the headset socket and USB OTG function multiplexing according to claim 1, wherein the control chip comprises:

A first data pin, which is used to implement the earphone detection pin;

A second data pin, used to implement USB audio switching pins;

A third data pin, used to realize the USB power pin;

One data acquisition pin, used to realize USB audio detection pin;

An ID pin, used to realize the USB ID pin;

A data negative signal pin, used to realize the USB OTG negative voltage pin;

One data positive signal pin, used to realize the USB OTG positive voltage pin;

An audio first output pin for realizing the left audio channel;

An audio second output pin, used to implement the audio right channel.
The method for using the headset socket and USB OTG function multiplexing according to claim 4, wherein the switching unit further comprises:

A first switching pin connected to the second data pin;

A positive voltage terminal connected to the data positive signal pin;

A negative voltage terminal connected to the data negative signal pin;

A left channel pin connected to the first audio output pin;

A right channel pin is connected to the second audio output pin.
The method for multiplexing the functions of an earphone holder and USB OTG according to claim 1, wherein the multiplexing circuit comprises:

A first power terminal, providing a first power voltage;

A second power terminal providing a second power voltage;

A third power supply terminal, providing a third power supply voltage;

A fourth power supply terminal, providing a fourth power supply voltage;

A multiplexing unit, the multiplexing unit is respectively connected to the first voltage terminal, the second power terminal, the third power terminal, the fourth voltage terminal, the control chip and the earphone socket between.
The method for multiplexing the functions of a headset and USB OTG according to claim 6, wherein the multiplexing unit comprises:

A triode, the emitter of the triode is connected to the third data pin, and the base of the triode is connected to the second voltage terminal through a second resistor;

A MOS tube, the gate of the MOS tube is connected to the collector of the triode through a third resistor, the source of the MOS tube is connected to the third power terminal, and the drain of the MOS tube is connected to the earphone The first pin of the socket;

A fourth resistor, connected between the fourth power terminal and the data acquisition pin through a diode;

A fifth resistor connected between the first pin of the earphone socket and the data collection pin;

A sixth resistor connected between the data collection pin and the ground terminal;

A seventh resistor connected between the third power terminal and the collector of the triode;

An eighth resistor, connected between the ID pin and the emitter of the triode;

A ninth resistor connected between the first data pin and the second power terminal;

A tenth resistor, connected between the fourth pin of the earphone holder and the ground terminal;

A first capacitor connected between the first power terminal and the ground terminal;

A second capacitor is connected between the third power terminal and the gate of the MOS transistor.
The method for using the headset socket and USB OTG function multiplexing according to claim 6, wherein the step S2 comprises:

Step S20: Judge whether the level of the first data pin changes, and when the level of the first data pin changes, go to step S21;

Step S21: Detect the voltage value of the data collection pin to determine the external device inserted into the earphone socket.
The method for using the earphone socket and USB OTG function multiplexing according to claim 6, wherein in the step S21, when the voltage value of the data collection pin is detected as a first preset value, it is determined Insert the earphone cable out of the earphone socket;

When detecting that the voltage value of the data collection pin is a second preset value, it is determined that the earphone holder is inserted into the USB host device;

When detecting that the voltage value of the data collection pin is a third preset value, it is determined that the earphone holder is inserted into a USB external device.
The method for using a headset socket and USB OTG function multiplexing according to claim 9, wherein the first preset value is 0.64V;

The second preset value is 0.80V;

The third preset value is 1.67V.