CN107643998B

CN107643998B - System for realizing OTG and charging dual functions based on intelligent module

Info

Publication number: CN107643998B
Application number: CN201710801156.3A
Authority: CN
Inventors: 高玉全; 杨希望; 孙延明
Original assignee: Quectel Wireless Solutions Co Ltd
Current assignee: Quectel Wireless Solutions Co Ltd
Priority date: 2017-09-07
Filing date: 2017-09-07
Publication date: 2020-04-10
Anticipated expiration: 2037-09-07
Also published as: CN107643998A

Abstract

The invention discloses a system for realizing double functions of OTG and charging based on an intelligent module, which comprises the intelligent module, a switching circuit, an adapter input end and a USB port, wherein the intelligent module comprises a USB functional unit, a charging management unit and a GPIO pin, the intelligent module acquires the type of connected equipment according to a USB specification, namely the intelligent module indicates that the adapter and OTG slave equipment coexist when detecting that a USB power supply pin is changed from low level to high level and a USB ID pin is changed from high level to low level, and the intelligent module sets the GPIO pin to high level to control the switching circuit to use the adapter as a power supply of the intelligent module to charge and supply the power supply of the intelligent module to the OTG slave equipment, thereby realizing the double functions of OTG and charging. The invention separates the adapter from the power supply hardware of the OTG slave equipment through the switching circuit, and realizes the complete separation by controlling the switching circuit through the software flow to realize the dual functions of the OTG and the charging.

Description

System for realizing OTG and charging dual functions based on intelligent module

Technical Field

The invention relates to the field of intelligent equipment, in particular to a system for realizing the double functions of OTG and charging based on an intelligent module.

Background

When an existing intelligent terminal uses an OTG (On the Go, which is mainly applied to connection among various different devices or mobile devices for data exchange) slave device, the intelligent terminal is a host device, and the intelligent terminal is a device during charging, so that the intelligent terminal does not support charging when the OTG slave device is used, or the OTG slave device is not supported during charging, but more and more customers need to charge the intelligent terminal device as the host device, so as to ensure that the device is not powered off due to battery exhaustion in the continuous use process.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defect that the intelligent terminal in the prior art does not support charging when using the OTG slave device or does not support the OTG slave device during charging, and provide a system for realizing the OTG and charging functions based on an intelligent module.

The invention solves the technical problems through the following technical scheme:

a system for realizing double functions of OTG and charging based on an intelligent module is characterized by comprising an intelligent module, a switching circuit, an adapter input end and a USB port, wherein the intelligent module comprises a USB functional unit, a charging management unit and a GPIO pin, the USB functional unit comprises a USB power supply pin, a USB data positive terminal pin, a USB data negative terminal pin and a USB ID pin, the charging management unit comprises a power supply pin, the switching circuit comprises a first port, a second port, a third port and a control port, the USB port is used for connecting OTG slave equipment, the adapter input end is used for connecting an adapter, and the power supply pin is connected with a power supply of the intelligent module;

the USB data positive terminal pin, the USB data negative terminal pin and the USB ID pin are correspondingly connected with the USB port, the input end of the adapter is respectively connected with the first port and the USB power supply pin, the GPIO pin is connected with the control port, the power supply end of the USB port is connected with the second port, and the power supply pin is connected with the third port;

when the intelligent module detects that the USB power supply pin is changed from a low level to a high level and the intelligent module detects that the USB ID pin is changed from a high level to a low level, the intelligent module sets the GPIO pin to be the high level to control the switching circuit to disconnect the second port from the first port and connect the second port with the third port, the intelligent module obtains power from the input end of the adapter through the USB power supply pin, the charging management unit charges the power supply of the intelligent module through the power supply pin and the power supply of the intelligent module supplies power to the OTG device through the switching circuit, and the intelligent module completes data exchange with the OTG slave device through the USB data positive pin and the USB data negative pin.

In this scheme, the USB functional unit is configured to enable the intelligent module to implement a USB function, for example, when the device connected to the USB port is an OTG slave device, according to the USB specification, the OTG slave device pulls down the USB ID pin to make the intelligent module a host, and the OTG function can be implemented through built-in software, and when the device connected to the USB port is a master device such as a PC (personal computer), according to the USB specification, the master device connects the USB data positive terminal pin and the USB data negative terminal pin in a short circuit, so that there is no level difference between the two pins, and then the intelligent module serves as a device, and enables USB charging and/or data communication through built-in software, for example, when the USB power supply pin is connected to an external power source such as an adapter, the pin level changes from a low level to a high level, and according to the USB specification, the intelligent module knows that the USB power supply pin is connected to the external power source, at this time, the intelligent module obtains power from the external power supply, and charges the power supply of the intelligent module through the charging management unit. Therefore, when the intelligent module detects that the USB power supply pin changes from low level to high level and the intelligent module detects that the USB ID pin changes from high level to low level, namely, the intelligent module detects that both an external power supply and an OTG slave device are connected, and then the intelligent module sets the GPIO pin to be high level, so that on one hand, the switching circuit uses the external power supply to supply power to the intelligent module and performs charging management on a power supply of the intelligent module, such as a battery, through the charging management unit, and on the other hand, the switching circuit supplies power to the OTG slave device from the power supply of the intelligent module, at this time, the intelligent module completes data exchange with the OTG slave equipment through the USB data positive electrode pin and the USB data negative electrode pin, so that the intelligent module realizes coexistence of the OTG function and the charging function.

Preferably, when the intelligent module detects that the USB power supply pin and the USB data negative terminal pin are in a low level state and the USB data positive terminal pin and the USB ID pin are in a high level state, the intelligent module sets the GPIO pin to a low level by default, the switching circuit includes a first resistor, a second resistor, a first triode, a second triode, and a PMOS transistor, a drain of the PMOS transistor is used as the first port, a source of the PMOS transistor is connected to one end of the first resistor and one end of the second resistor respectively and then used as the second port, a gate of the PMOS transistor is connected to the other end of the first resistor and a collector of the first triode respectively, an emitter of the first triode is grounded, a base of the first triode is connected to the other end of the second resistor and a collector of the second triode respectively, and the emitter of the second triode is grounded, and the base of the second triode is used as the control port.

In the scheme, the switching circuit utilizes the switching characteristics of an MOS (metal oxide semiconductor) tube and a triode, and the switching circuit is based on the condition that the input end of the adapter and the USB port are in a suspended state, the GPIO pin is in a low level, so that the system for realizing the OTG and charging dual functions based on the intelligent module still has the complete and independent OTG function and charging function on the basis of having the OTG function and the charging function, namely, the system is independent when the input end of the adapter is connected with the adapter, the system for realizing the OTG and charging dual functions based on the intelligent module can be independently charged, and independently can independently carry out OTG communication or independently when the USB port is connected with the OTG slave equipment, the intelligent module can realize communication as device. Certainly, insert OTG slave unit and adapter simultaneously, the system that realizes OTG and charge dual function based on intelligent object just has the OTG function simultaneously and charges the function.

Preferably, the charging management unit further includes a power supply voltage detection pin, the power supply voltage detection pin is connected to the power supply of the intelligent module, and when the charging management unit detects that the power supply of the intelligent module is in a fully charged state, the charging management unit stops charging the power supply of the intelligent module through the power supply pin.

In this scheme, through monitoring thereby the decision whether continues to charge of the electric quantity state of intelligent object's power supply, further improve reliability and security.

Preferably, the switching circuit further includes a third resistor, one end of the third resistor is connected to the base of the second triode, and the other end of the third resistor is grounded.

Preferably, the switching circuit further includes a voltage stabilizing circuit, the voltage stabilizing circuit further includes an enable terminal, the enable terminal is connected to the control port, the input terminal of the voltage stabilizing circuit is the third port, the output terminal of the voltage stabilizing circuit is the second port, and the enable terminal is a high level which is effectively used for controlling the voltage stabilizing circuit to stabilize the power supply of the intelligent module and then output the power supply through the second port.

In the scheme, the voltage stabilizing circuit is utilized to match the power supply of the intelligent module with the power supply requirement of the OTG slave equipment so as to further improve the use flexibility of the system for realizing the OTG and charging dual functions based on the intelligent module. The voltage stabilizing circuit generally adopts a voltage stabilizing chip as a core device, and in view of the fact that in the existing application, the working voltage range of an intelligent module is generally 3.5V-4.2V, and the power supply voltage of an OTG slave device is generally 5V, namely the voltage value of the power supply of the intelligent module is lower than the power supply requirement of the OTG slave device, the voltage stabilizing circuit adopts a boost voltage stabilizing chip.

Preferably, the voltage stabilizing circuit further comprises a diode, an output end of the voltage stabilizing circuit is connected with an anode of the diode, and a cathode of the diode is used as the second port. In the scheme, the voltage stabilizing circuit is protected by utilizing the unidirectional conduction characteristic of the diode, and the reliability and the safety of the circuit are improved.

The positive progress effects of the invention are as follows: according to the invention, the input of the external adapter power supply and the power supply of the OTG slave equipment are separated by hardware through adding the switching circuit, and the switching circuit is controlled through a General Purpose input/output (GPIO) interface in combination with a software process, so that the input of the external adapter power supply and the power supply of the OTG slave equipment are completely separated, and the intelligent equipment simultaneously supports the OTG slave equipment and a charging function.

Drawings

Fig. 1 is a schematic diagram of a system for implementing both OTG and charging functions based on an intelligent module according to a preferred embodiment of the present invention.

Fig. 2 is a schematic flowchart of the built-in software of the system for implementing both OTG and charging functions based on the intelligent module according to the preferred embodiment of the present invention.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.

As shown in fig. 1-2, the system for implementing both OTG and charging functions based on an intelligent module according to this embodiment includes an intelligent module 1, a switching circuit 2, an adapter input end 3, and a USB port 4, where the intelligent module 1 includes a USB functional unit 11, a charging management unit 12, and GPIO pins, the USB functional unit 11 includes a USB power supply pin USB _ VBUS, a USB data positive terminal pin USB _ DP, a USB data negative terminal pin USB _ DN, and a USB ID pin USB _ ID, the charging management unit 12 includes a power supply pin VBAT, the switching circuit 2 includes a first port 21, a second port 22, a third port 23, and a control port 24, the USB port 4 is used for connecting an OTG slave device, the adapter input end 3 is used for connecting an adapter, and the power supply pin VBAT is connected to a power supply 5 of the intelligent module;

the USB data positive terminal pin USB _ DP, the USB data negative terminal pin USB _ DN, and the USB ID pin USB _ ID are correspondingly connected to the USB port 4, the adapter input terminal 3 is respectively connected to the first port 21 and the USB power supply pin USB _ VBUS, the GPIO pin is connected to the control port 24, the power supply terminal of the USB port 4 is connected to the second port 22, and the power supply pin VBAT is connected to the third port 23;

when the intelligent module 1 detects that the USB power supply pin USB _ VBUS changes from low level to high level and the intelligent module 1 detects that the USB ID pin USB _ ID changes from high level to low level according to a built-in software flow (as shown in fig. 2), the intelligent module 1 sets the GPIO pin to high level for controlling the switching circuit 2 to disconnect the second port 22 from the first port 21 and to connect the second port 22 with the third port 23, the intelligent module 1 obtains power from the adapter input 3 through the USB power supply pin USB _ VBUS, and the charging management unit 12 charges the power supply 5 of the intelligent module 1 through the power supply pin VBAT and the power supply 5 of the intelligent module 1 supplies power to the OTG slave (the OTG slave is not identified in fig. 1) through the switching circuit 2, the intelligent module 1 completes data exchange with the OTG slave device through the USB data positive pin USB _ DP and the USB data negative pin USB _ DN. In the specific implementation of this embodiment, the power supply 5 of the intelligent module 1 is preferably a battery, such as a lithium battery, and may be a single lithium battery or two lithium batteries connected in parallel, where the voltage of the single lithium battery is generally 4.2V; the intelligent module 1 comprises an intelligent chip, such as a direct optimized high-pass msm8909 platform, as a core of the intelligent module, which comprises functional units of USB, charge management, etc., so that when the device connected to the USB port 4 is an OTG slave device, according to the USB specification, the OTG slave device pulls down the USB ID pin USB _ ID, so that the intelligent module 1 becomes a host, and the OTG function can be realized through the built-in software, and when the device connected to the USB port 4 is a master device (the master device is not identified in fig. 1), such as a PC (personal computer), according to the USB specification, the master device short-circuits the USB data positive terminal pin USB _ DP and the USB data negative terminal pin USB _ DN together, so that there is no level difference between the two pins, so that the intelligent module 1 serves as a device, and the USB charge and/or data communication can be realized through the built-in software, for another example, when the USB power supply pin USB _ VBUS is connected to an external power source such as an adapter, the pin level changes from low level to high level, and according to the USB specification, the intelligent module can know that the USB power supply pin USB _ VBUS is connected to the external power source, and then the intelligent module 1 obtains the power source from the external power source, and charges the power supply 5 of the intelligent module 1 through the charging management unit 12. Therefore, when the intelligent module 1 detects that the USB power supply pin USB _ VBUS changes from low level to high level and the intelligent module 1 detects that the USB ID pin USB _ ID changes from high level to low level, that is, when the intelligent module 1 detects that both an external power supply and an OTG slave are connected, the intelligent module 1 sets the GPIO pin to high level, on one hand, the switching circuit 2 uses the external power supply to supply power to the intelligent module 1 and performs charge management on the power supply 5 of the intelligent module 1 through the charge management unit 12, on the other hand, the switching circuit 2 supplies power to the OTG slave from the power supply 5 of the intelligent module 1, and then the intelligent module 1 completes data exchange with the OTG slave through the USB data positive pin USB _ DP, the USB data negative USB _ DN and the OTG slave, the intelligent module thus realizes coexistence of the OTG function and the charging function.

Further, in this embodiment, when the intelligent module 1 detects that the USB power supply pin USB _ VBUS and the USB data negative terminal pin USB _ DN are all in a low level state and the USB data positive terminal pin USB _ DP and the USB ID pin USB _ ID are all in a high level state, the intelligent module 1 sets the GPIO pin to be in a low level by default, the switching circuit 2 includes a first resistor R1, a second resistor R2, a first transistor Q2, a second transistor Q3, and a PMOS transistor Q1, the drain of the PMOS transistor Q1 is used as the first port 21, the source of the PMOS transistor Q1 is connected to one end of the first resistor R1 and one end of the second resistor R2 respectively and then is used as the second port 22, the gate of the PMOS transistor Q1 is connected to the other end of the first resistor R1 and the collector of the first transistor Q2, the emitter of the first transistor Q2 is grounded, the base of the first triode Q2 is connected to the other end of the second resistor R2 and the collector of the second triode Q3, respectively, the emitter of the second triode Q3 is grounded, and the base of the second triode Q3 is used as the control port 24. During specific implementation, the GPIO pin is set to be low level through a built-in software process according to the adapter input end and the USB port are both in a suspended state, so that the system for realizing the OTG and charging dual functions based on the intelligent module still has complete and independent OTG functions and charging functions on the basis of the coexistence of the OTG function and the charging function, namely, when the adapter input end 3 is connected with the adapter independently, the system for realizing the OTG and charging dual functions based on the intelligent module can be independently charged, and when the USB port 4 is connected into an OTG slave device independently, OTG communication can be independently carried out or when the USB port 4 is connected into a master device independently, the intelligent module 1 is used as device to realize communication. Certainly, insert OTG slave unit and adapter simultaneously, the system that realizes OTG and charge dual function based on intelligent object just has the OTG function simultaneously and charges the function. In a specific implementation, the switching circuit 2 further includes a third resistor R3, wherein one end of the third resistor R3 is connected to the base of the second transistor Q3, and the other end is grounded.

Further, in this embodiment, the charging management unit 12 further includes a power supply voltage detection pin BAT _ SNS, the power supply voltage detection pin BAT _ SNS is connected to the power supply 5 of the intelligent module 1, and when the charging management unit 12 detects that the power supply 5 of the intelligent module 1 is in a fully charged state, the charging management unit 12 stops charging the power supply 5 of the intelligent module 1 through the power supply pin BAT _ SNS.

Further, in this embodiment, the switching circuit 1 further includes a voltage stabilizing circuit 25, the voltage stabilizing circuit further includes an enable terminal EN, the voltage stabilizing circuit 25 preferably selects the voltage stabilizing chip 251 as a core device of the voltage stabilizing circuit, the voltage stabilizing circuit 25 further includes a diode D1, an output terminal of the voltage stabilizing circuit 25 is connected to an anode of the diode D1, a cathode of the diode D1 is connected to the second port 22, the enable terminal EN is connected to the control port 24, an input terminal of the voltage stabilizing circuit 25 is the third port 23, an output terminal of the voltage stabilizing circuit 25 is the second port 22, and the enable terminal EN is a high level and is effective for controlling the voltage stabilizing circuit 25 to stabilize the power supply 5 of the intelligent module 1 and then output the power supply through the second port 22. In specific implementation, the working voltage range of the intelligent module is generally 3.5-4.2V, and the power supply of the OTG slave device is 5V, that is, the voltage value of the power supply of the intelligent module is lower than the power supply requirement of the OTG slave device, so that the boost voltage stabilizing circuit is adopted.

As shown in fig. 2, the built-in software process of the system for implementing both OTG and charging functions based on the intelligent module according to the present embodiment includes: firstly, the intelligent module 1 detects whether the USB port 4 is suspended according to the USB specification, for example, when the intelligent module 1 detects that the USB power supply pin USB _ VBUS and the USB data negative terminal pin USB _ DN are in a low level state and the USB data positive terminal pin USB _ DP and the USB ID pin USB _ ID are in a high level state, it indicates that the USB port 4 is in a suspended state; then, if it is detected that the USB port 4 is connected to a device, according to the USB specification, whether the USB port is an OTG slave device or a master device is identified through the USB ID pin USB _ ID, the USB data positive terminal pin USB _ DP, and the USB data negative terminal pin USB _ DN, if the level of the USB ID pin USB _ ID changes from high to low, the USB port is an OTG slave device, otherwise the USB port is a master device, the intelligent module 1 is used as device, and further, it is determined whether an adapter is inserted, that is, it is determined whether the level of the USB power supply pin USB _ VBUS changes from low to high, at this time, if the adapter and the OTG slave device coexist, the OTG and charging functions are executed, and if the USB port is only an OTG slave device, the OTG function is executed only; if it is detected that the adapter input end 3 is connected to the adapter, that is, it is detected whether the level of the USB power supply pin USB _ VBUS changes from low to high, indicating that the adapter input end 3 is connected to the adapter, then it is further determined whether the USB port 4 is connected to the device, that is, according to the USB specification, it is identified whether the OTG slave device or the master device is through the USB ID pin USB _ ID, the USB data positive terminal pin USB _ DP, and the USB data negative terminal pin USB _ DN, if the OTG slave device is an OTG slave device, if the adapter and the OTG slave device coexist, the OTG and charging function is executed, and if the adapter is an adapter only, the charging function is executed; when the USB port 4 and the adapter input end 3 are both in a suspended state, the process is always in a waiting state.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.

Claims

1. A system for realizing OTG and charging double functions based on an intelligent module is characterized by comprising the intelligent module, a switching circuit, an adapter input end and a USB port, wherein the intelligent module comprises a USB functional unit, a charging management unit and a GPIO pin, the USB functional unit comprises a USB power supply pin, a USB data positive terminal pin, a USB data negative terminal pin and a USBID pin, the charging management unit comprises a power supply pin, the switching circuit comprises a first port, a second port, a third port and a control port, the USB port is used for connecting OTG slave equipment, the adapter input end is used for connecting an adapter, and the power supply pin in the charging management unit is connected with a power supply of the intelligent module;

when the intelligent module detects that the USB power supply pin is changed from low level to high level and the intelligent module detects that the USB ID pin is changed from high level to low level, the intelligent module sets the GPIO pin to be in high level to control the switching circuit to disconnect the second port from the first port and to connect the second port with the third port, the intelligent module draws power from the adapter input through the USB power pin, and the charging management unit charges the power supply of the intelligent module through the power supply pin in the charging management unit and the power supply of the intelligent module supplies power to the OTG slave device through the switching circuit, and the intelligent module completes data exchange with the OTG slave equipment through the USB data positive pin and the USB data negative pin.

2. The system according to claim 1, wherein when the intelligent module detects that the USB power supply pin, the USB data negative terminal pin are all in a low state and the USB data positive terminal pin and the USB bit pin are all in a high state, the intelligent module sets the GPIO pin to a low level by default, the switching circuit comprises a first resistor, a second resistor, a first triode, a second triode, and a PMOS transistor, wherein a drain of the PMOS transistor is used as the first port, a source of the PMOS transistor is connected to one end of the first resistor and one end of the second resistor respectively and then used as the second port, a gate of the PMOS transistor is connected to the other end of the first resistor and a collector of the first triode, an emitter of the first triode is grounded, and a base of the first triode is connected to the other end of the second resistor respectively and a base of the second triode respectively, And the collector of the second triode is connected, the emitter of the second triode is grounded, and the base of the second triode is used as the control port.

3. The dual-function OTG and charging system based on intelligent module as claimed in claim 1, wherein the charging management unit further comprises a supply voltage detection pin, the supply voltage detection pin is connected to the power supply of the intelligent module, when the charging management unit detects that the power supply of the intelligent module is in a fully charged state, the charging management unit stops charging the power supply of the intelligent module through the supply pin.

4. The dual-function OTG and charging system based on intelligent module as claimed in claim 2, wherein said switching circuit further comprises a third resistor, one end of said third resistor is connected to the base of said second transistor, and the other end is grounded.

5. The dual OTG and charging function system based on an intelligent module as claimed in claim 1, wherein the switching circuit further comprises a voltage regulator circuit, the voltage regulator circuit further comprises an enable terminal, the enable terminal is connected to the control port, the input terminal of the voltage regulator circuit is the third port, the output terminal of the voltage regulator circuit is the second port, and the enable terminal is at a high level effective for controlling the voltage regulator circuit to stabilize the power supply of the intelligent module and then output the power supply through the second port.

6. The dual OTG and charging function system based on an intelligent module as claimed in claim 5, wherein the voltage regulator circuit further comprises a diode, the output terminal of the voltage regulator circuit is connected to the anode of the diode, and the cathode of the diode is used as the second port.