我是USB和Android的新手，所以如果我不清楚自己解释，请原谅我。
我有一个可在Windows中与之通信的USB HID设备。我正在尝试使用运行Android 3.1的Acer Iconia A500平板电脑建立通信。
我能够找到设备，枚举它，获得唯一可用的接口，获得唯一可用的端点（0），并确定它是什么类型的端点（从设备到主机传输中断）。
我对USB规范的理解是，所有HID设备都需要具有控制端点（端点0）和中断IN端点。但似乎这里的端点0是中断输入端点，而不是控制端点。
然而，为了使设备枚举，它必须成功地在控制端点上传输其描述符数据。因此，我推断控制端点必须找到（并使用），因为主机确实枚举了设备。
这是我能够继续进行的，如上所述，在应用程序级别呈现给我的唯一接口/端点是从设备到主机的中断类型。我的应用程序没有可用的端点从主机到设备，中断或控制。因此，设备等待被告知该做什么，并且主机等待设备中发生的事情。不太刺激。
请记住，此设备在连接到Windows时会正确响应，例如我能够发送包含13个字节数据的报告，该报告使设备点亮LED。所以它似乎符合USB HID规范。作为一种绝望的行为，我尝试将这一个端点用作控制端点和中断OUT端点，使用controltransfer（）和UsbRequest（）将数据提交给设备，在任何一种情况下都没有响应。
所以我的问题是：“控制传输端点是（？）用于设置设备，为什么我无法找到并使用它？”
感谢您的任何见解，以下是相关代码，如果需要，我可以将其余内容全部包括在内：
private UsbManager mUsbManager;
private UsbDevice mDevice;
private UsbDeviceConnection mConnectionRead;
private UsbDeviceConnection mConnectionWrite;
private UsbEndpoint mEndpointRead;
private UsbEndpoint mEndpointWrite;
// check for existing devices
for (UsbDevice device : mUsbManager.getDeviceList().values())
{
//Need to filter for my device when other HIDs are also connected, but for now...
String devName = device.getDeviceName();
if (DEBUG == 1){
Toast.makeText(UsbHidDeviceTesterActivity.this, "My device got connected: " + devName, Toast.LENGTH_LONG).show();
}
//mDevice = device;
setHIDDevice(device);
}
private boolean setHIDDevice(UsbDevice device)
{
UsbInterface usbInterfaceRead = null;
UsbInterface usbInterfaceWrite = null;
UsbEndpoint ep1 = null;
UsbEndpoint ep2 = null;
boolean UsingSingleInterface = true;
mDevice = device;
//This HID device is using a single interface
if (UsingSingleInterface)
{
//usbInterfaceRead = device.getInterface(0x00);//only 1 EP on this interface
usbInterfaceRead = findInterface(device);
//Try getting an interface at next index
//usbInterfaceWrite = device.getInterface(0x01);//throws exception
// Try using the same interface for reading and writing
usbInterfaceWrite = usbInterfaceRead;
int endPointCount = usbInterfaceWrite.getEndpointCount();
if (DEBUG == 2)
{
Toast.makeText(UsbHidDeviceTesterActivity.this, "Endpoints: " + endPointCount, Toast.LENGTH_LONG).show();
//Toast.makeText(UsbHidDeviceTesterActivity.this, "Interface: " + usbInterfaceRead, Toast.LENGTH_LONG).show();
}
if (endPointCount == 1)//only getting 1 endpoint
{
ep1 = usbInterfaceRead.getEndpoint(0);
//As an act of desperation try equating ep2 to this read EP, so that we can later attempt to write to it anyway
ep2 = usbInterfaceRead.getEndpoint(0);
}
else if (endPointCount == 2)
{
ep1 = usbInterfaceRead.getEndpoint(0);
ep2 = usbInterfaceRead.getEndpoint(1);
}
}
else // ! UsingSingleInterface
{
usbInterfaceRead = device.getInterface(0x00);
usbInterfaceWrite = device.getInterface(0x01);
if ((usbInterfaceRead.getEndpointCount() == 1) && (usbInterfaceWrite.getEndpointCount() == 1))
{
ep1 = usbInterfaceRead.getEndpoint(0);
ep2 = usbInterfaceWrite.getEndpoint(0);
}
if (DEBUG == 3)
{
Toast.makeText(UsbHidDeviceTesterActivity.this, "Using Dual Interface", Toast.LENGTH_LONG).show();
}
}
//because ep1 = ep2 this will now not cause a return unless no ep is found at all
if ((ep1 == null) || (ep2 == null))
{
if (DEBUG == 4)
{
Toast.makeText(UsbHidDeviceTesterActivity.this, "One EP is null", Toast.LENGTH_LONG).show();
}
return false;
}
// Determine which endpoint is the read, and which is the write
if (ep1.getType() == UsbConstants.USB_ENDPOINT_XFER_INT)//I am getting a return of 3, which is an interrupt transfer
{
if (ep1.getDirection() == UsbConstants.USB_DIR_IN)//I am getting a return of 128, which is a device-to-host endpoint
{
mEndpointRead = ep1;
if (DEBUG == 5)
{
Toast.makeText(UsbHidDeviceTesterActivity.this, "EP1 type: " + ep1.getType(), Toast.LENGTH_LONG).show();
}
}
if (ep1.getDirection() == UsbConstants.USB_DIR_OUT)//nope
{
mEndpointWrite = ep1;
if (DEBUG == 6)
{
Toast.makeText(UsbHidDeviceTesterActivity.this, "EP1 is a write", Toast.LENGTH_LONG).show();
}
}
}
if (ep2.getType() == UsbConstants.USB_ENDPOINT_XFER_INT)
{
if (ep2.getDirection() == UsbConstants.USB_DIR_IN)
{
//Try treating it as a write anyway
//mEndpointRead = ep2;
mEndpointWrite = ep2;
}
else if (ep2.getDirection() == UsbConstants.USB_DIR_OUT)
{
//usbEndpointWrite = ep2;
mEndpointWrite = ep2;
}
}
//check that we should be able to read and write
if ((mEndpointRead == null) || (mEndpointWrite == null))
{
return false;
}
if (device != null)
{
UsbDeviceConnection connection = mUsbManager.openDevice(device);
if (connection != null && connection.claimInterface(usbInterfaceRead, true))
{
Log.d(TAG, "open SUCCESS");
mConnectionRead = connection;
// Start the read thread
//Comment out while desperately attempting to write on this connection/interface
//Thread thread = new Thread(this);
//thread.start();
}
else
{
Log.d(TAG, "open FAIL");
mConnectionRead = null;
}
}
if (UsingSingleInterface)
{
mConnectionWrite = mConnectionRead;
}
else //! UsingSingleInterface
{
mConnectionWrite = mUsbManager.openDevice(device);
mConnectionWrite.claimInterface(usbInterfaceWrite, true);
}
return true;
}
// searches for an interface on the given USB device
private UsbInterface findInterface(UsbDevice device) {
Log.d(TAG, "findInterface " + device);
int count = device.getInterfaceCount();
if (DEBUG == 7)
{
Toast.makeText(UsbHidDeviceTesterActivity.this, "Interface count: " + count, Toast.LENGTH_LONG).show();
}
for (int i = 0; i < count; i++) {
UsbInterface intf = device.getInterface(i);
String InterfaceInfo = intf.toString();
Log.d(TAG, "Interface: " + InterfaceInfo);
//Class below is 3 for USB_HID
if (intf.getInterfaceClass() == 3 && intf.getInterfaceSubclass() == 0 &&
intf.getInterfaceProtocol() == 0) {
return intf;
}
//....try just returning the interface regardless of class/subclass
//return intf;
}
return null;
}
private boolean sendControlTransfer(byte[] dataToSend)
{
synchronized (this)
{
if (mConnectionRead != null)
{
//byte[] message = new byte[13]; // or 14?
byte[] message = dataToSend;
if (DEBUG == 9)
{
Toast.makeText(UsbHidDeviceTesterActivity.this, "Sending Control Transfer", Toast.LENGTH_LONG).show();
}
//first field ox21 is bin 00100001 which splits into 0 01 00001 for direction(1bit)/type(2b)/recipient(5b)
//To set direction as 'host to Device' we need 0, To set type to HID we need 11 (3), and for recipient we want 00001
//second field 0x09 is class specific request code, 0x09 is listed as 'reserved for future use'
//third field 0x200 is value
//int transfer = mConnectionRead.controlTransfer(0x21, 0x9, 0x200, 0, message, message.length, 0);
//try with type set to HID
int transfer = mConnectionRead.controlTransfer(0xC1, 0x9, 0x200, 0, message, message.length, 0);
if (DEBUG == 10)
{
Toast.makeText(UsbHidDeviceTesterActivity.this, "Transfer returned " + transfer, Toast.LENGTH_LONG).show();
}
}
}
return true;
}
private boolean sendInterruptTransfer(byte[] dataToSend)
{
int bufferDataLength = mEndpointWrite.getMaxPacketSize();//The write endpoint is null unless we just copy the read endpoint
if (DEBUG == 12)
{
Toast.makeText(UsbHidDeviceTesterActivity.this, "Max Packet Size: " + bufferDataLength, Toast.LENGTH_LONG).show();
}
ByteBuffer buffer = ByteBuffer.allocate(bufferDataLength + 1);
UsbRequest request = new UsbRequest();
buffer.put(dataToSend);
request.initialize(mConnectionWrite, mEndpointWrite);
request.queue(buffer, bufferDataLength);
try
{
/* only use requestwait on a read
if (request.equals(mConnectionWrite.requestWait()))
{
return true;
}
*/
}
catch (Exception ex)
{
// An exception has occurred
if (DEBUG == 13)
{
Toast.makeText(UsbHidDeviceTesterActivity.this, "Caught Write Exception", Toast.LENGTH_LONG).show();
}
}
return true;
}
答案 0 :(得分：10)
您可以使用以下命令获取接口和端点详细信息的完整列表：
UsbManager mManager = (UsbManager) getSystemService(Context.USB_SERVICE);
HashMap<String, UsbDevice> deviceList = mManager.getDeviceList();
Iterator<UsbDevice> deviceIterator = deviceList.values().iterator();
while (deviceIterator.hasNext())
{
UsbDevice device = deviceIterator.next();
Log.i(TAG,"Model: " + device.getDeviceName());
Log.i(TAG,"ID: " + device.getDeviceId());
Log.i(TAG,"Class: " + device.getDeviceClass());
Log.i(TAG,"Protocol: " + device.getDeviceProtocol());
Log.i(TAG,"Vendor ID " + device.getVendorId());
Log.i(TAG,"Product ID: " + device.getProductId());
Log.i(TAG,"Interface count: " + device.getInterfaceCount());
Log.i(TAG,"---------------------------------------");
// Get interface details
for (int index = 0; index < device.getInterfaceCount(); index++)
{
UsbInterface mUsbInterface = device.getInterface(index);
Log.i(TAG," ***** *****");
Log.i(TAG," Interface index: " + index);
Log.i(TAG," Interface ID: " + mUsbInterface.getId());
Log.i(TAG," Inteface class: " + mUsbInterface.getInterfaceClass());
Log.i(TAG," Interface protocol: " + mUsbInterface.getInterfaceProtocol());
Log.i(TAG," Endpoint count: " + mUsbInterface.getEndpointCount());
// Get endpoint details
for (int epi = 0; epi < mUsbInterface.getEndpointCount(); epi++)
{
UsbEndpoint mEndpoint = mUsbInterface.getEndpoint(epi);
Log.i(TAG," ++++ ++++ ++++");
Log.i(TAG," Endpoint index: " + epi);
Log.i(TAG," Attributes: " + mEndpoint.getAttributes());
Log.i(TAG," Direction: " + mEndpoint.getDirection());
Log.i(TAG," Number: " + mEndpoint.getEndpointNumber());
Log.i(TAG," Interval: " + mEndpoint.getInterval());
Log.i(TAG," Packet size: " + mEndpoint.getMaxPacketSize());
Log.i(TAG," Type: " + mEndpoint.getType());
}
}
}
Log.i(TAG," No more devices connected.");
}
答案 1 :(得分：9)
所以，我一直在研究类似的事情。我无法证实，但我认为正在发生的事情是：
答案 2 :(得分：4)
对于传入和传出传输，
控制传输不会显示任何接口描述符，并且其端点号默认为0。
如果你有其他接口，那些接口的索引应该从0开始，即默认控制传输接口不计算。
因此，您的接口0保存端点1描述符。使用UsbEndpoint方法查找端点的属性，无论它是否为中断类型。如果是那么UsbEndpoint.getType（）的端点类型应该返回0x03，并且UsbEndpoint.getEndpointNumber（）的端点号应该返回0x81，这是端点1的通常值。
你的代码下面的错误：
//first field ox21 is bin 00100001 which splits into 0 01 00001 for direction(1bit)/type(2b)/recipient(5b)
//To set direction as 'host to Device' we need 0, **To set type to HID we need 11 (3)**, and for recipient we want 00001
//second field 0x09 is class specific request code, **0x09 is listed as 'reserved for future use'**
//**third field 0x200 is value**
//int transfer = mConnectionRead.controlTransfer(0x21, 0x9, 0x200, 0, message, message.length, 0);
//try with type set to HID
int transfer = mConnectionRead.controlTransfer(0xC1, 0x9, 0x200, 0, message, message.length, 0);
类型2位用于指示特定于类的请求，即其值为01， 0x09是Hid类特定请求SET_REPORT，不保留。 value是用作Hid类的报告ID的wValue，对于您的情况，它可能是0，如果您在HID描述符上只有一个报告。 第四个参数是wIndex，它应该用来表示收件人，对于你的情况，接口作为收件人应该是0x01。
因此，您的读取或接收数据表单设备的控制传输代码应为：
int transfer = mConnectionRead.controlTransfer(0xA1, 0x01, 0x00, 0x01, message, message.length, 0);
其中第二个参数中的0x01是GET_REPORT是Hid调用特定请求。
用于写入或向设备发送数据的控制传输代码应为：
int transfer = mConnectionWrite.controlTransfer(0x21, 0x09, 0x00, 0x01, message, message.length, 0);
由于您只有中断IN端点1，因此批量或中断传输应该类似于：
int transfer = bulkTransfer (ep1, message, message.length, 0);
要设置中断Out端点，应该在设备固件的接口描述符处有一个端点描述符。