@ohos.usbManager (USB Manager)

The usbManager module provides USB device management functions, including USB device list query, bulk data transfer, control transfer, and permission control on the host side as well as port management, and function switch and query on the device side.

NOTE

The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import usb from "@ohos.usbManager";

usb.getDevices

getDevices(): Array<Readonly<USBDevice>>

Obtains the list of USB devices connected to the host. If no device is connected, an empty list is returned.

System capability: SystemCapability.USB.USBManager

Return value

Type	Description
Array<Readonly<USBDevice>>	USB device list.

Example

let devicesList: Array<usb.USBDevice> = usb.getDevices();
console.log(`devicesList = ${devicesList}`);
/*
The following is a simple example of the data structure for devicesList:
[
  {
    name: "1-1",
    serial: "",
    manufacturerName: "",
    productName: "",
    version: "",
    vendorId: 7531,
    productId: 2,
    clazz: 9,
    subClass: 0,
    protocol: 1,
    devAddress: 1,
    busNum: 1,
    configs: [
      {
        id: 1,
        attributes: 224,
        isRemoteWakeup: true,
        isSelfPowered: true,
        maxPower: 0,
        name: "1-1",
        interfaces: [
          {
            id: 0,
            protocol: 0,
            clazz: 9,
            subClass: 0,
            alternateSetting: 0,
            name: "1-1",
            endpoints: [
              {
                address: 129,
                attributes: 3,
                interval: 12,
                maxPacketSize: 4,
                direction: 128,
                number: 1,
                type: 3,
                interfaceId: 0,
              },
            ],
          },
        ],
      },
    ],
  },
]
*/

usb.connectDevice

connectDevice(device: USBDevice): Readonly<USBDevicePipe>

Connects to the USB device based on the device information returned by getDevices().

Before you do this, call usb.getDevices to obtain the USB device list and device information, and then call usb.requestRight to request the device access permission.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
device	USBDevice	Yes	USB device information.

Return value

Type	Description
Readonly<USBDevicePipe>	USB device pipe for data transfer.

Error codes

For details about the error codes, see USB Service Error Codes.

ID	Error Message
14400001	Permission denied. Need call requestRight to get permission.

Example

let devicesList: Array<usb.USBDevice> = usb.getDevices();
if (devicesList.length == 0) {
  console.log(`device list is empty`);
}

let device: usb.USBDevice = devicesList[0];
usb.requestRight(device.name);
let devicepipe: usb.USBDevicePipe = usb.connectDevice(device);
console.log(`devicepipe = ${devicepipe}`);

usb.hasRight

hasRight(deviceName: string): boolean

Checks whether the application has the permission to access the device.

Checks whether the user, for example, the application or system, has the device access permissions. The value true is returned if the user has the device access permissions; the value false is returned otherwise.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
deviceName	string	Yes	Device name.

Return value

Type	Description
boolean	Returns true if the application has the permission to access the device; returns false otherwise.

Example

let devicesName: string = "1-1";
let right: boolean = usb.hasRight(devicesName);
console.log(`${right}`);

usb.requestRight

requestRight(deviceName: string): Promise<boolean>

Requests the temporary device access permission for the application. This API uses a promise to return the result. System applications are granted the device access permission by default, and you do not need to apply for the permission separately.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
deviceName	string	Yes	Device name.

Return value

Type	Description
Promise<boolean>	Promise used to return the result. The value true indicates that the temporary device access permissions are granted; and the value false indicates the opposite.

Example

let devicesName: string = "1-1";
usb.requestRight(devicesName).then(ret => {
  console.log(`requestRight = ${ret}`);
});

usb.removeRight

removeRight(deviceName: string): boolean

Removes the device access permission for the application. System applications are granted the device access permission by default, and calling this API will not revoke the permission.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
deviceName	string	Yes	Device name.

Return value

Type	Description
boolean	Permission removal result. The value true indicates that the access permission is removed successfully; and the value false indicates the opposite.

Example

let devicesName: string = "1-1";
if (usb.removeRight(devicesName)) {
  console.log(`Succeed in removing right`);
}

usb.claimInterface

claimInterface(pipe: USBDevicePipe, iface: USBInterface, force ?: boolean): number

Claims a USB interface.

Before you do this, call usb.getDevices to obtain the USB device list and USB interfaces, call usb.requestRight to request the device access permission, and call usb.connectDevice to obtain devicepipe as an input parameter.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
pipe	USBDevicePipe	Yes	Device pipe, which is used to determine the bus number and device address.
iface	USBInterface	Yes	USB interface, which is used to determine the index of the interface to claim.
force	boolean	No	Whether to forcibly claim the USB interface. The default value is false, indicating not to forcibly claim the USB interface.

Return value

Type	Description
number	Returns 0 if the USB interface is successfully claimed; returns an error code otherwise.

Example

let devicesList: Array<usb.USBDevice> = usb.getDevices();
if (devicesList.length == 0) {
  console.log(`device list is empty`);
}

let device: usb.USBDevice = devicesList[0];
usb.requestRight(device.name);
let devicepipe: usb.USBDevicePipe = usb.connectDevice(device);
let interfaces: usb.USBInterface = device.configs[0].interfaces[0];
let ret: number= usb.claimInterface(devicepipe, interfaces);
console.log(`claimInterface = ${ret}`);

usb.releaseInterface

releaseInterface(pipe: USBDevicePipe, iface: USBInterface): number

Releases a USB interface.

Before you do this, ensure that you have claimed the interface by calling usb.claimInterface.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
pipe	USBDevicePipe	Yes	Device pipe, which is used to determine the bus number and device address.
iface	USBInterface	Yes	USB interface, which is used to determine the index of the interface to release.

Return value

Type	Description
number	Returns 0 if the USB interface is successfully released; returns an error code otherwise.

Example

let devicesList: Array<usb.USBDevice> = usb.getDevices();
if (devicesList.length == 0) {
  console.log(`device list is empty`);
}

let device: usb.USBDevice = devicesList[0];
usb.requestRight(device.name);
let devicepipe: usb.USBDevicePipe = usb.connectDevice(device);
let interfaces: usb.USBInterface = device.configs[0].interfaces[0];
let ret: number = usb.claimInterface(devicepipe, interfaces);
ret = usb.releaseInterface(devicepipe, interfaces);
console.log(`releaseInterface = ${ret}`);

usb.setConfiguration

setConfiguration(pipe: USBDevicePipe, config: USBConfiguration): number

Sets the device configuration.

Before you do this, call usb.getDevices to obtain the USB device list and device configuration, call usb.requestRight to request the device access permission, and call usb.connectDevice to obtain devicepipe as an input parameter.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
pipe	USBDevicePipe	Yes	Device pipe, which is used to determine the bus number and device address.
config	USBConfiguration	Yes	USB configuration to set.

Return value

Type	Description
number	Returns 0 if the USB configuration is successfully set; returns an error code otherwise.

Example

let devicesList: Array<usb.USBDevice> = usb.getDevices();
if (devicesList.length == 0) {
  console.log(`device list is empty`);
}

let device: usb.USBDevice = devicesList[0];
usb.requestRight(device.name);
let devicepipe: usb.USBDevicePipe = usb.connectDevice(device);
let config: usb.USBConfiguration = device.configs[0];
let ret: number= usb.setConfiguration(devicepipe, config);
console.log(`setConfiguration = ${ret}`);

usb.setInterface

setInterface(pipe: USBDevicePipe, iface: USBInterface): number

Sets a USB interface.

Before you do this, call usb.getDevices to obtain the USB device list and interfaces, call usb.requestRight to request the device access permission, call usb.connectDevice to obtain devicepipe as an input parameter, and call usb.claimInterface to claim the USB interface.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
pipe	USBDevicePipe	Yes	Device pipe, which is used to determine the bus number and device address.
iface	USBInterface	Yes	USB interface to set.

Return value

Type	Description
number	Returns 0 if the USB interface is successfully set; returns an error code otherwise.

Example

let devicesList: Array<usb.USBDevice> = usb.getDevices();
if (devicesList.length == 0) {
  console.log(`device list is empty`);
}

let device: usb.USBDevice = devicesList[0];
usb.requestRight(device.name);
let devicepipe: usb.USBDevicePipe = usb.connectDevice(device);
let interfaces: usb.USBInterface = device.configs[0].interfaces[0];
let ret: number = usb.claimInterface(devicepipe, interfaces);
ret = usb.setInterface(devicepipe, interfaces);
console.log(`setInterface = ${ret}`);

usb.getRawDescriptor

getRawDescriptor(pipe: USBDevicePipe): Uint8Array

Obtains the raw USB descriptor.

Before you do this, call usb.getDevices to obtain the USB device list, call usb.requestRight to request the device access permission, and call usb.connectDevice to obtain devicepipe as an input parameter.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
pipe	USBDevicePipe	Yes	Device pipe, which is used to determine the bus number and device address.

Return value

Type	Description
Uint8Array	Returns the raw USB descriptor if the operation is successful; returns undefined otherwise.

Example

let devicesList: Array<usb.USBDevice> = usb.getDevices();
if (devicesList.length == 0) {
  console.log(`device list is empty`);
}

usb.requestRight(devicesList[0].name);
let devicepipe: usb.USBDevicePipe = usb.connectDevice(devicesList[0]);
let ret: Uint8Array = usb.getRawDescriptor(devicepipe);

usb.getFileDescriptor

getFileDescriptor(pipe: USBDevicePipe): number

Obtains the file descriptor.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
pipe	USBDevicePipe	Yes	Device pipe, which is used to determine the bus number and device address.

Return value

Type	Description
number	Returns the file descriptor of the USB device if the operation is successful; returns -1 otherwise.

Example

let devicesList: Array<usb.USBDevice> = usb.getDevices();
if (devicesList.length == 0) {
  console.log(`device list is empty`);
}

usb.requestRight(devicesList[0].name);
let devicepipe: usb.USBDevicePipe = usb.connectDevice(devicesList[0]);
let ret: number = usb.getFileDescriptor(devicepipe);

usb.controlTransfer

controlTransfer(pipe: USBDevicePipe, controlparam: USBControlParams, timeout ?: number): Promise<number>

Performs control transfer.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
pipe	USBDevicePipe	Yes	USB device pipe, which is used to determine the USB device.
controlparam	USBControlParams	Yes	Control transfer parameters.
timeout	number	No	Timeout duration in ms. This parameter is optional. The default value is 0, indicating no timeout.

Return value

Type	Description
Promise<number>	Promise used to return the result, which is the size of the transmitted or received data block if the transfer is successful, or -1 if an exception has occurred.

Example

class PARA {
  request: number = 0
  reqType: usb.USBControlRequestType = 0
  target: usb.USBRequestTargetType = 0
  value: number = 0
  index: number = 0
  data: Uint8Array = new Uint8Array()
}

let param: PARA = {
  request: 0,
  reqType: 0,
  target:0,
  value: 0,
  index: 0,
  data: new Uint8Array()
};

let devicesList: Array<usb.USBDevice> = usb.getDevices();
if (devicesList.length == 0) {
  console.log(`device list is empty`);
}

usb.requestRight(devicesList[0].name);
let devicepipe: usb.USBDevicePipe = usb.connectDevice(devicesList[0]);
usb.controlTransfer(devicepipe, param).then((ret: number) => {
 console.log(`controlTransfer = ${ret}`);
})

usb.bulkTransfer

bulkTransfer(pipe: USBDevicePipe, endpoint: USBEndpoint, buffer: Uint8Array, timeout ?: number): Promise<number>

Performs bulk transfer.

Before you do this, call usb.getDevices to obtain the USB device list and endpoints, call usb.requestRight to request the device access permission, call usb.connectDevice to obtain devicepipe as an input parameter, and call usb.claimInterface to claim the USB interface.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
pipe	USBDevicePipe	Yes	USB device pipe, which is used to determine the USB device.
endpoint	USBEndpoint	Yes	USB endpoint, which is used to determine the USB port for data transfer.
buffer	Uint8Array	Yes	Buffer used to write or read data.
timeout	number	No	Timeout duration in ms. This parameter is optional. The default value is 0, indicating no timeout.

Return value

Type	Description
Promise<number>	Promise used to return the result, which is the size of the transmitted or received data block if the transfer is successful, or -1 if an exception has occurred.

Example

// Call usb.getDevices to obtain a data set. Then, obtain a USB device and its access permission.
// Pass the obtained USB device as a parameter to usb.connectDevice. Then, call usb.connectDevice to connect the USB device.
// Call usb.claimInterface to claim the USB interface. After that, call usb.bulkTransfer to start bulk transfer.
let devicesList: Array<usb.USBDevice> = usb.getDevices();
if (devicesList.length == 0) {
  console.log(`device list is empty`);
}

let device: usb.USBDevice = devicesList[0];
usb.requestRight(device.name);

let devicepipe: usb.USBDevicePipe = usb.connectDevice(device);
let interfaces: usb.USBInterface = device.configs[0].interfaces[0];
let endpoint: usb.USBEndpoint = device.configs[0].interfaces[0].endpoints[0];
let ret: number = usb.claimInterface(devicepipe, interfaces);
let buffer =  new Uint8Array(128);
usb.bulkTransfer(devicepipe, endpoint, buffer).then((ret: number) => {
  console.log(`bulkTransfer = ${ret}`);
});

usb.closePipe

closePipe(pipe: USBDevicePipe): number

Closes a USB device pipe.

System capability: SystemCapability.USB.USBManager

Parameters

Name	Type	Mandatory	Description
pipe	USBDevicePipe	Yes	USB device pipe.

Return value

Type	Description
number	Returns 0 if the USB device pipe is closed successfully; returns an error code otherwise.

Example

let devicesList: Array<usb.USBDevice> = usb.getDevices();
if (devicesList.length == 0) {
  console.log(`device list is empty`);
}

usb.requestRight(devicesList[0].name);
let devicepipe: usb.USBDevicePipe = usb.connectDevice(devicesList[0]);
let ret: number = usb.closePipe(devicepipe);
console.log(`closePipe = ${ret}`);

USBEndpoint

Represents the USB endpoint from which data is sent or received. You can obtain the USB endpoint through USBInterface.

System capability: SystemCapability.USB.USBManager

Name	Type	Mandatory	Description
address	number	Yes	Endpoint address.
attributes	number	Yes	Endpoint attributes.
interval	number	Yes	Endpoint interval.
maxPacketSize	number	Yes	Maximum size of data packets on the endpoint.
direction	USBRequestDirection	Yes	Endpoint direction.
number	number	Yes	Endpoint number.
type	number	Yes	Endpoint type.
interfaceId	number	Yes	Unique ID of the interface to which the endpoint belongs.

USBInterface

Represents a USB interface. One USBConfiguration object can contain multiple USBInterface instances, each providing a specific function.

System capability: SystemCapability.USB.USBManager

Name	Type	Mandatory	Description
id	number	Yes	Unique ID of the USB interface.
protocol	number	Yes	Interface protocol.
clazz	number	Yes	Device type.
subClass	number	Yes	Device subclass.
alternateSetting	number	Yes	Settings for alternating between descriptors of the same USB interface.
name	string	Yes	Interface name.
endpoints	Array<USBEndpoint>	Yes	Endpoints that belong to the USB interface.

USBConfiguration

Represents the USB configuration. One USBDevice can contain multiple USBConfig instances.

System capability: SystemCapability.USB.USBManager

Name	Type	Mandatory	Description
id	number	Yes	Unique ID of the USB configuration.
attributes	number	Yes	Configuration attributes.
maxPower	number	Yes	Maximum power consumption, in mA.
name	string	Yes	Configuration name, which can be left empty.
isRemoteWakeup	boolean	Yes	Support for remote wakeup.
isSelfPowered	boolean	Yes	Support for independent power supplies.
interfaces	Array <USBInterface>	Yes	Supported interface attributes.

USBDevice

Represents the USB device information.

System capability: SystemCapability.USB.USBManager

Name	Type	Mandatory	Description
busNum	number	Yes	Bus address.
devAddress	number	Yes	Device address.
serial	string	Yes	Sequence number.
name	string	Yes	Device name.
manufacturerName	string	Yes	Device manufacturer.
productName	string	Yes	Product name.
version	string	Yes	Version number.
vendorId	number	Yes	Vendor ID.
productId	number	Yes	Product ID.
clazz	number	Yes	Device class.
subClass	number	Yes	Device subclass.
protocol	number	Yes	Device protocol code.
configs	Array<USBConfiguration>	Yes	Device configuration descriptor information.

USBDevicePipe

Represents a USB device pipe, which is used to determine a USB device.

System capability: SystemCapability.USB.USBManager

Name	Type	Mandatory	Description
busNum	number	Yes	Bus address.
devAddress	number	Yes	Device address.

USBControlParams

Represents control transfer parameters.

System capability: SystemCapability.USB.USBManager

Name	Type	Mandatory	Description
request	number	Yes	Request type.
target	USBRequestTargetType	Yes	Request target type.
reqType	USBControlRequestType	Yes	Control request type.
value	number	Yes	Request parameter value.
index	number	Yes	Index of the request parameter value.
data	Uint8Array	Yes	Buffer for writing or reading data.

USBRequestTargetType

Enumerates request target types.

System capability: SystemCapability.USB.USBManager

Name	Value	Description
USB_REQUEST_TARGET_DEVICE	0	Device.
USB_REQUEST_TARGET_INTERFACE	1	Interface.
USB_REQUEST_TARGET_ENDPOINT	2	Endpoint.
USB_REQUEST_TARGET_OTHER	3	Other.

USBControlRequestType

Enumerates control request types.

System capability: SystemCapability.USB.USBManager

Name	Value	Description
USB_REQUEST_TYPE_STANDARD	0	Standard.
USB_REQUEST_TYPE_CLASS	1	Class.
USB_REQUEST_TYPE_VENDOR	2	Vendor.

USBRequestDirection

Enumerates request directions.

System capability: SystemCapability.USB.USBManager

Name	Value	Description
USB_REQUEST_DIR_TO_DEVICE	0	Request for writing data from the host to the device.
USB_REQUEST_DIR_FROM_DEVICE	0x80	Request for reading data from the device to the host.