@ohos.usb (USB Manager) (No Longer Maintained)
The usb module provides USB device management functions, including USB device list query, bulk data transfer, control transfer, and permission control.
NOTE
The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
The APIs provided by this module are no longer maintained since API version 9. You are advised to use @ohos.usbManager.
Modules to Import
import usb from "@ohos.usb";
usb.getDevices
getDevices(): Array<Readonly<USBDevice>>
Obtains the USB device list.
System capability: SystemCapability.USB.USBManager
Return value
| Type | Description |
|---|---|
| Array<Readonly<USBDevice>> | USB device list. |
Example
let devicesList = usb.getDevices();
console.log(`devicesList = ${devicesList}`);
// devicesList is a list of USB devices.
// A simple example of devicesList is provided as follows:
/*[
{
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 a USB device.
Before you do this, call usb.getDevices to obtain the USB device list, 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. |
Example
let devicepipe= usb.connectDevice(device);
console.log(`devicepipe = ${devicepipe}`);
usb.hasRight
hasRight(deviceName: string): boolean
Checks whether the application has the permission to access the device.
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= "1-1";
let bool = usb.hasRight(devicesName);
console.log(`hasRight = ${bool}`);
usb.requestRight
requestRight(deviceName: string): Promise<boolean>
Requests the temporary permission for the application to access a USB device. 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= "1-1";
usb.requestRight(devicesName).then((ret) => {
console.log(`requestRight = ${ret}`);
});
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 ret = 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 ret = usb.releaseInterface(devicepipe, interfaces);
console.log(`releaseInterface = ${ret}`);
usb.setConfiguration
setConfiguration(pipe: USBDevicePipe, config: USBConfig): 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 | USBConfig | 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 ret = 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 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 ret = usb.getRawDescriptor(devicepipe);
usb.getFileDescriptor
getFileDescriptor(pipe: USBDevicePipe): number
Obtains the file 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 |
|---|---|
| number | Returns the file descriptor of the USB device if the operation is successful; returns -1 otherwise. |
Example
let ret = usb.getFileDescriptor(devicepipe);
usb.controlTransfer
controlTransfer(pipe: USBDevicePipe, controlparam: USBControlParams, timeout ?: number): Promise<number>
Performs control transfer.
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 | 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
let param = {
request: 0,
reqType: 0,
target:0,
value: 0,
index: 0,
data: null
};
usb.controlTransfer(devicepipe, param).then((ret) => {
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 for writing or reading 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.
usb.bulkTransfer(devicepipe, endpoint, buffer).then((ret) => {
console.log(`bulkTransfer = ${ret}`);
});
usb.closePipe
closePipe(pipe: USBDevicePipe): number
Closes a USB device pipe.
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 | 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 ret = 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 USBConfig 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. |
USBConfig
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. |
| 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<USBConfig> | 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. |