UsbDeviceConnection

bulkTransfer

public 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.

bulkTransfer

public 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(android.hardware.usb.UsbEndpoint, byte[], int, int, int).

claimInterface

public 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.

close

public void close ()

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

controlTransfer

public 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 & UsbConstants#USB_ENDPOINT_DIR_MASK is UsbConstants#USB_DIR_OUT, then the transfer is a write, and if it is UsbConstants#USB_DIR_IN, then the transfer is a read.

controlTransfer

public 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 & UsbConstants#USB_ENDPOINT_DIR_MASK is UsbConstants#USB_DIR_OUT, then the transfer is a write, and if it is UsbConstants#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).

getFileDescriptor

public 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.

getRawDescriptors

public 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.

getSerial

public String getSerial ()

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

releaseInterface

public boolean releaseInterface (UsbInterface intf)

Releases exclusive access to a UsbInterface.

requestWait

public UsbRequest requestWait (long timeout)

Waits for the result of a UsbRequest.queue(ByteBuffer) operation

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

Android processes UsbRequests asynchronously. Hence it is not guaranteed that requestWait(0) returns a request that has been queued right before even if the request could have been processed immediately.

requestWait

public UsbRequest requestWait ()

Waits for the result of a UsbRequest.queue(ByteBuffer) operation

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

setConfiguration

public boolean setConfiguration (UsbConfiguration configuration)

Sets the device's current UsbConfiguration.

setInterface

public boolean setInterface (UsbInterface intf)

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

finalize

protected void finalize ()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. A subclass overrides the finalize method to dispose of system resources or to perform other cleanup.

The general contract of finalize is that it is invoked if and when the Java virtual machine has determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, except as a result of an action taken by the finalization of some other object or class which is ready to be finalized. The finalize method may take any action, including making this object available again to other threads; the usual purpose of finalize, however, is to perform cleanup actions before the object is irrevocably discarded. For example, the finalize method for an object that represents an input/output connection might perform explicit I/O transactions to break the connection before the object is permanently discarded.

The finalize method of class Object performs no special action; it simply returns normally. Subclasses of Object may override this definition.

The Java programming language does not guarantee which thread will invoke the finalize method for any given object. It is guaranteed, however, that the thread that invokes finalize will not be holding any user-visible synchronization locks when finalize is invoked. If an uncaught exception is thrown by the finalize method, the exception is ignored and finalization of that object terminates.

After the finalize method has been invoked for an object, no further action is taken until the Java virtual machine has again determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, including possible actions by other objects or classes which are ready to be finalized, at which point the object may be discarded.

The finalize method is never invoked more than once by a Java virtual machine for any given object.

Any exception thrown by the finalize method causes the finalization of this object to be halted, but is otherwise ignored.