Patent Publication Number: US-2022237136-A1

Title: Switching method of usb switch element for in-vehicle host system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of TW application serial No. 110102873, filed on Jan. 26, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of specification. 
     FIELD OF DISCLOSURE 
     The present invention relates to a switching method and in particular, to a switching method of a universal serial bus (USB) switch element for an in-vehicle host system. 
     DESCRIPTION OF RELATED ART 
     With rapid development of communication technology and information technology, in-vehicle host systems usually integrate mobile phones, navigation, music playing functions, and audio-visual playing functions. This allows automobile manufacturers to create various functional operating interfaces for drivers to facilitate the safe use of information, entertainment, navigation, and other services. In conventional techniques, the in-vehicle host system can only provide one communication device (such as a mobile phone), and this communication device communicates in a host mode with the in-vehicle host system, so that different applications in the communication device can be displayed on the in-vehicle host system, which facilitates operations and communications of the drivers. However, the in-vehicle host system cannot switch between two communication devices, which makes it difficult for users with two different communication devices to control the in-vehicle host system by using the host mode of the in-vehicle host system. In view of this, there is a need to develop a new switching method to improve the above problems. 
     SUMMARY 
     It is an objective of the present invention to provide a switching method of a universal serial bus (USB) switch element for an in-vehicle host system. A switch device enables the in-vehicle host system to switch between multiple mobile terminals, so that users with multiple different mobile terminals can easily control the in-vehicle host system by using a host mode of the in-vehicle host system. 
     Accordingly, the present invention provides a switching method of a universal serial bus (USB) switch element for an in-vehicle host system, comprising following steps: 
     an in-vehicle host device initializes a switch device; 
     the in-vehicle host device transmits a switching command to the switch device via a host port; 
     the switch device receives the switching command; and 
     according to the switching command, a hub controller of the switch device controls the switch element to switch from a device mode to a host mode, so that one of a plurality of mobile terminals connected to the switch element is in the host mode, or alternatively the switch element is controlled to switch from the host mode to the device mode, so that a plurality of peripheral devices connected to the hub device are in the device mode; 
     wherein the device mode is a state in which the in-vehicle host device controls the peripheral devices through a hub device; the host mode is a state in which any one of the mobile terminals controls the in-vehicle host device during the host mode; and when the switch device is in the host mode, the hub device disables the peripheral devices. 
     In one embodiment of the present invention, the step where the in-vehicle host device initializes the switch device further comprises following steps: 
     the in-vehicle host device sets the switch device in the device mode to communicate with the hub controller of the hub device; and 
     the in-vehicle host device detects a voltage level of a voltage pin of the host port. 
     In one embodiment of the present invention, the voltage pin is a VBUS voltage pin. 
     In one embodiment of the present invention, before the step where the in-vehicle host device transmits the switching command to the switch device via the host port, the in-vehicle host device resets a VBUS voltage level of the VBUS voltage pin to increase from zero to a predetermined level. 
     In one embodiment of the present invention, when the switch device is in the device mode or the host mode, the hub device enables the mobile terminals to be in a rechargeable state. 
     In one embodiment of the present invention, a plurality of charge controllers are coupled between the switch element and the mobile terminals to control charging between the in-vehicle host device and each of the mobile terminals. 
     In one embodiment of the present invention, a plurality of peripheral controllers are coupled between the hub device and the peripheral devices to control a communication link between the in-vehicle host device and each of the peripheral devices. 
     In one embodiment of the present invention, the mobile terminals comprise a first mobile terminal and a second mobile terminal, and the hub controller controls the switch element to switch from the host mode of the first mobile terminal to the host mode of the second mobile terminal according to the switching command. 
     In one embodiment of the present invention, when one of the first mobile terminal and the second mobile terminal is in the host mode, one of the first mobile terminal and the second mobile terminal transmits data or a control command to the in-vehicle host device through the switch element to control operations of the in-vehicle host device. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       In order to explain the technical solutions of the present invention more clearly, drawings which will be described in the embodiments are briefly introduced hereinafter. Obviously, the accompanying drawings described below are only some embodiments of the present invention. Persons of ordinary skills in the art are able to obtain other drawings based on these drawings. 
         FIG. 1  is a diagram showing an in-vehicle host system with a universal serial bus (USB) switch element according to one embodiment of the present invention. 
         FIG. 2  is a process flow diagram illustrating a switching method of the USB switch element for the in-vehicle host system according to one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     In the accompanying drawings, same symbols/numerals are used to indicate same components or similar components. Working principles of the present invention are described as being implemented in an appropriate computing environment as an example. The following description is provided with reference to specific embodiments of the present invention, and should not be construed as limiting other specific embodiments of the present invention that are not described in detail herein. 
     Referring to  FIG. 1 , it illustrates an in-vehicle host system with a universal serial bus 
     (USB) switch element according to one embodiment of the present invention. The in-vehicle host system comprises an in-vehicle host device  100  and a switch device  102 . The in-vehicle host device  100  is configured to initialize the switch device  102 , and the in-vehicle host device  100  transmits a switching command SI to the switch device  102  through a host port  104 , wherein the host port  104  is provided with a voltage pin, so that the in-vehicle host device  100  can detect a voltage level of the voltage pin. The in-vehicle host device  100  and the switch device  102  of the present invention are compatible with a USB protocol. The in-vehicle host device  100  of the present invention is configured to switch between different mobile terminals  114  such as mobile phones. As shown in  FIG. 2 , the mobile terminals  114  comprise a first mobile terminal  114   a  and a second mobile terminal  114   b , but the present application is not limited in this regard. The in-vehicle host device  100  of the in-vehicle host system is controlled by the mobile terminal  114  switched to, so that an operating interface of an application program of the mobile terminal  114  is displayed on a display (not illustrated) of the in-vehicle host device  100 . 
     As shown in  FIG. 1 , the switch device  102  is coupled to the in-vehicle host device  100  for receiving the switching command SI. The switch device  102  comprises a switch element  106 , a hub device  108 , a plurality of charging controllers  110 , and a plurality of peripheral controllers  112 . The switch element  106  is coupled to the host port  104  of the in-vehicle host device  100 , the hub device  108  is coupled to the switch element  106 , the charging controllers  110  are coupled between the switch element  106  and the mobile terminals  114 , and the peripheral controllers  112  are coupled between the hub device  108  and peripheral devices  116 . In one embodiment, each of the charging controllers  110  is connected to a corresponding one of the mobile terminals  114  through a first connection port  117 , and each of the peripheral controllers  112  is connected to a corresponding one of the peripheral devices  116  through a second connection port  119 . In one embodiment, the switch element  106  is, for example, a multiplexer under control of the hub device  108 . 
     In  FIG. 1 , the switch element  106  receives the switching command SI and is configured to switch between a device mode M 1  and a host mode M 2 , wherein the device mode M 1  is defined as a state in which the in-vehicle host device  100  can control the peripheral devices  116  through the hub device  108 , so that the peripheral devices  116  execute commands or programs sent by the in-vehicle host device  100 . The host mode M 2  is defined as a state in which any one of the mobile terminals  114  can control the in-vehicle host device  100  during the host mode M 2 , so that the in-vehicle host device  100  can execute commands or programs sent by the mobile terminal  114 . The hub device  108  comprises a hub controller  109 . The hub controller  109  controls the switch element  106  to switch from the device mode M 1  to the host mode M 2  according to the switching command SI, e.g., a control command SC, so that one of the mobile terminals  114  connected to the switch element  106  is in the host mode M 2 ; or alternatively, the hub controller  109  controls the switch element  106  to switch from the host mode M 2  to the device mode M 1  according to the switching command SI, e.g., the control command SC, so that the peripheral devices  116  connected to the hub device  108  is in the device mode M 1 . The charging controllers  110  are used to control charging between the in-vehicle host device  100  and the mobile terminals  114 . Each of the peripheral controllers  112  is configured to control a communication link between the in-vehicle host device  100  and a corresponding one of the peripheral devices  116 . It should be noted that any one of the mobile terminals  114  of the present invention can also be in the device mode M 1 , and it is preferable that only one of the mobile terminals  114  of the present invention is in the host mode M 2 . 
     With reference to  FIGS. 1 and 2 ,  FIG. 2  is a process flow diagram illustrating a switching method of the USB switch element for the in-vehicle host system according to one embodiment of the present invention. The switching method comprises following steps: 
     In step S 200 , the in-vehicle host device  100  initializes the switch device  102 . In one embodiment, the step where the in-vehicle host device  100  initializes the switch device  102  further comprises following steps: the in-vehicle host device  100  sets the switch device  102  in the device mode M 1  to communicate with the hub controller  109  of the hub device  108 . In one embodiment, information of the initialized device mode M 1  can be stored in a status register  105 ; and the in-vehicle host device  100  detects a voltage level of a voltage pin of the host port  104 . In one embodiment, the voltage pin is a VBUS voltage pin. 
     In step S 202 , the in-vehicle host device  100  resets the voltage level of the voltage pin. In one embodiment, the in-vehicle host device  100  resets a VBUS voltage level of the VBUS voltage pin to increase from zero to a predetermined level. In other words, before switching between the device mode M 1  and the host mode M 2 , the in-vehicle host device  100  first resets the VBUS voltage level. For example, the VBUS voltage level is reset to zero and is raised by the predetermined level to perform the subsequent switching between the device mode M 1  and the host mode M 2 . 
     In step S 204 , the in-vehicle host device  100  transmits the switching command SI to the switch device  102  through the host port  104  to control the switch device  102  to switch between the mobile terminals  114  and the peripheral devices  116 . The host port  104  is, for example, a USB OTG (on-the-go) port. 
     In step S 206 , the switch device  102  receives the switching command SI. The switching command SI is compatible with the USB protocol, for example. 
     In step S 208 , the hub controller  109  of the switch device  102  controls the switch element  106  to switch from the device mode M 1  to the host mode M 2  according to the switching command SI, e.g., the control command SC, so that one of the mobile terminals  114  (e.g., the first mobile terminal  114   a  or the second mobile terminal  114   b ) connected to the switch element  106  is in the host mode M 2 ; or alternatively, the switch element  106  is controlled to switch from the host mode M 2  to the device mode M 1 , through the control command SC for example, so that the peripheral devices  116  connected to the hub device  108  are in the device mode M 1 . The device mode M 1  is defined as the state where the in-vehicle host device  100  can control the peripheral devices  116  through the hub device  108 . The host mode M 2  is defined as the state where any one of the mobile terminals  114  is in the host mode M 2  and can control the in-vehicle host device  100 . When the switch device  102  is in the host mode M 2 , the hub device  108  disables the peripheral devices. It should be noted that any one of the mobile terminals  114  of the present invention can also be in the device mode M 1 , and it is preferable that the present invention sets only one of the mobile terminals  114  to be in the host mode M 2 . 
     In step S 208  according to one embodiment, when the switch device  102  is in the device mode M 1  or the host mode M 2 , the hub device  108  enables the mobile terminals  114  to be chargeable. The charging controllers  110  are coupled between the switch element  106  and the mobile terminals  114  to control the charging between the in-vehicle host device  100  and the mobile terminals  114 . In one embodiment, the peripheral controllers  112  are coupled between the hub device  108  and the peripheral devices  116  to control the communication link between the in-vehicle host device  100  and each of the peripheral devices  116 . 
     In step S 208  according to one embodiment, the mobile terminals  114  comprise a first mobile terminal  114   a  and a second mobile terminal  114   b , and the hub controller  109  controls the switch element  106  to switch from the host mode M 2  of the first mobile terminal  114   a  to the host mode M 2  of the second mobile terminal  114   b  according to the switching command SI. When one of the first mobile terminal  114   a  and the second mobile terminal  114   b  is in the host mode M 2 , one of the first mobile terminal  114   a  and the second mobile terminal  114   b  transmits data SD or a communication command SCI to the in-vehicle host device  100  through the switch element  106  to control operations of the in-vehicle host device  100 . 
     In summary, the switching method of the USB switch element for the in-vehicle host system of the present invention enables the in-vehicle host system to switch between multiple mobile terminals through the switch device, so that users with multiple different mobile terminals can easily control the in-vehicle host system by using the host mode of the in-vehicle host system. 
     Although the present invention has been disclosed as above with reference to preferable embodiments, the present invention is not limited to the above description. Persons of ordinary skills in the art can make various modifications and changes without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be defined by the appended claims.