Skip to content

Most visited

Recently visited

navigation

UsbDeviceConnection

public class UsbDeviceConnection
extends Object

java.lang.Object
   ↳ android.hardware.usb.UsbDeviceConnection


This class is used for sending and receiving data and control messages to a USB device. Instances of this class are created by openDevice(UsbDevice).

Summary

Public methods

int bulkTransfer(UsbEndpoint endpoint, byte[] buffer, int offset, int length, int timeout)

Performs a bulk transaction on the given endpoint.

int bulkTransfer(UsbEndpoint endpoint, byte[] buffer, int length, int timeout)

Performs a bulk transaction on the given endpoint.

boolean claimInterface(UsbInterface intf, boolean force)

Claims exclusive access to a UsbInterface.

void close()

Releases all system resources related to the device.

int controlTransfer(int requestType, int request, int value, int index, byte[] buffer, int offset, int length, int timeout)

Performs a control transaction on endpoint zero for this device.

int controlTransfer(int requestType, int request, int value, int index, byte[] buffer, int length, int timeout)

Performs a control transaction on endpoint zero for this device.

int getFileDescriptor()

Returns the native file descriptor for the device, or -1 if the device is not opened.

byte[] getRawDescriptors()

Returns the raw USB descriptors for the device.

String getSerial()

Returns the serial number for the device.

boolean releaseInterface(UsbInterface intf)

Releases exclusive access to a UsbInterface.

UsbRequest requestWait()

Waits for the result of a queue(ByteBuffer, int) operation Note that this may return requests queued on multiple UsbEndpoints.

boolean setConfiguration(UsbConfiguration configuration)

Sets the device's current UsbConfiguration.

boolean setInterface(UsbInterface intf)

Sets the current UsbInterface.

Inherited methods

From class java.lang.Object

Public methods

bulkTransfer

Added in API level 18
int bulkTransfer (UsbEndpoint endpoint, 
                byte[] buffer, 
                int offset, 
                int length, 
                int timeout)

Performs a bulk transaction on the given endpoint. The direction of the transfer is determined by the direction of the endpoint.

Parameters
endpoint UsbEndpoint: the endpoint for this transaction
buffer byte: buffer for data to send or receive
offset int: the index of the first byte in the buffer to send or receive
length int: the length of the data to send or receive
timeout int: in milliseconds
Returns
int length of data transferred (or zero) for success, or negative value for failure

bulkTransfer

Added in API level 12
int bulkTransfer (UsbEndpoint endpoint, 
                byte[] buffer, 
                int length, 
                int timeout)

Performs a bulk transaction on the given endpoint. The direction of the transfer is determined by the direction of the endpoint.

This method transfers data starting from index 0 in the buffer. To specify a different offset, use bulkTransfer(UsbEndpoint, byte[], int, int, int).

Parameters
endpoint UsbEndpoint: the endpoint for this transaction
buffer byte: buffer for data to send or receive
length int: the length of the data to send or receive
timeout int: in milliseconds
Returns
int length of data transferred (or zero) for success, or negative value for failure

claimInterface

Added in API level 12
boolean claimInterface (UsbInterface intf, 
                boolean force)

Claims exclusive access to a UsbInterface. This must be done before sending or receiving data on any UsbEndpoints belonging to the interface.

Parameters
intf UsbInterface: the interface to claim
force boolean: true to disconnect kernel driver if necessary
Returns
boolean true if the interface was successfully claimed

close

Added in API level 12
void close ()

Releases all system resources related to the device. Once the object is closed it cannot be used again. The client must call openDevice(UsbDevice) again to retrieve a new instance to reestablish communication with the device.

controlTransfer

Added in API level 18
int controlTransfer (int requestType, 
                int request, 
                int value, 
                int index, 
                byte[] buffer, 
                int offset, 
                int length, 
                int timeout)

Performs a control transaction on endpoint zero for this device. The direction of the transfer is determined by the request type. If requestType & USB_ENDPOINT_DIR_MASK is USB_DIR_OUT, then the transfer is a write, and if it is USB_DIR_IN, then the transfer is a read.

Parameters
requestType int: request type for this transaction
request int: request ID for this transaction
value int: value field for this transaction
index int: index field for this transaction
buffer byte: buffer for data portion of transaction, or null if no data needs to be sent or received
offset int: the index of the first byte in the buffer to send or receive
length int: the length of the data to send or receive
timeout int: in milliseconds
Returns
int length of data transferred (or zero) for success, or negative value for failure

controlTransfer

Added in API level 12
int controlTransfer (int requestType, 
                int request, 
                int value, 
                int index, 
                byte[] buffer, 
                int length, 
                int timeout)

Performs a control transaction on endpoint zero for this device. The direction of the transfer is determined by the request type. If requestType & USB_ENDPOINT_DIR_MASK is USB_DIR_OUT, then the transfer is a write, and if it is USB_DIR_IN, then the transfer is a read.

This method transfers data starting from index 0 in the buffer. To specify a different offset, use controlTransfer(int, int, int, int, byte[], int, int, int).

Parameters
requestType int: request type for this transaction
request int: request ID for this transaction
value int: value field for this transaction
index int: index field for this transaction
buffer byte: buffer for data portion of transaction, or null if no data needs to be sent or received
length int: the length of the data to send or receive
timeout int: in milliseconds
Returns
int length of data transferred (or zero) for success, or negative value for failure

getFileDescriptor

Added in API level 12
int getFileDescriptor ()

Returns the native file descriptor for the device, or -1 if the device is not opened. This is intended for passing to native code to access the device.

Returns
int the native file descriptor

getRawDescriptors

Added in API level 13
byte[] getRawDescriptors ()

Returns the raw USB descriptors for the device. This can be used to access descriptors not supported directly via the higher level APIs.

Returns
byte[] raw USB descriptors

getSerial

Added in API level 12
String getSerial ()

Returns the serial number for the device. This will return null if the device has not been opened.

Returns
String the device serial number

releaseInterface

Added in API level 12
boolean releaseInterface (UsbInterface intf)

Releases exclusive access to a UsbInterface.

Parameters
intf UsbInterface
Returns
boolean true if the interface was successfully released

requestWait

Added in API level 12
UsbRequest requestWait ()

Waits for the result of a queue(ByteBuffer, int) operation Note that this may return requests queued on multiple UsbEndpoints. When multiple endpoints are in use, getEndpoint() and getClientData() can be useful in determining how to process the result of this function.

Returns
UsbRequest a completed USB request, or null if an error occurred

setConfiguration

Added in API level 21
boolean setConfiguration (UsbConfiguration configuration)

Sets the device's current UsbConfiguration.

Parameters
configuration UsbConfiguration
Returns
boolean true if the configuration was successfully set

setInterface

Added in API level 21
boolean setInterface (UsbInterface intf)

Sets the current UsbInterface. Used to select between two interfaces with the same ID but different alternate setting.

Parameters
intf UsbInterface
Returns
boolean true if the interface was successfully selected
This site uses cookies to store your preferences for site-specific language and display options.

Hooray!

This class requires API level or higher

This doc is hidden because your selected API level for the documentation is . You can change the documentation API level with the selector above the left navigation.

For more information about specifying the API level your app requires, read Supporting Different Platform Versions.

Take a one-minute survey?
Help us improve Android tools and documentation.