我认为试图编译一个特定的C程序，它允许通过USB控制Gembird SilverShield电源插座为Android。在我的android HDMI电视棒上，这将非常有用。有一个开放的项目this。它在Linux下工作，取决于libusb。目标平台是android ICS。我想在Ubuntu Linux上开发。我有什么机会让它工作？什么是必需的步骤。安装android SDK，NDK，交叉编译器...
有一个旧的问题here，与Android上的libusb相关，但没有信息如何。
将应用程序移植到androids自己的usb库可能更容易吗？编译并链接到Android的libusb
Libusb可以在非root的android上工作（假设设备支持USB主机...这是非常重要的，因为并非所有的设备都是如此）。你需要使用标准的android USB栈。然后您可以从USBDevice获取设备描述符并将其传递给libusb。
不幸的是，您还需要修改libusb。幸运的是，其他人已经解释了您需要如何修改LibUSB。
LibUSB已被修改here。
祝你好运！
编辑：
首先，你需要定义一个广播接收器：
private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver()
{
public void onReceive(Context context, Intent intent)
{
String action = intent.getAction();
if (ACTION_USB_PERMISSION.equals(action))
{
synchronized (this)
{
UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false))
{
if(device != null)
{
UsbDeviceConnection deviceConnection = mUsbManager.openDevice(device);
Log.d("USB", deviceConnection.getSerial());
}
}
else
{
Log.d("USB", "permission denied for device " + device);
}
}
}
}
}
现在，你需要创建一个USBManager和枚举的设备：
mUsbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
HashMap< String, UsbDevice > stringDeviceMap = mUsbManager.getDeviceList();
Collection<UsbDevice> usbDevices = stringDeviceMap.values();
mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(ACTION_USB_PERMISSION), 0);
IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
registerReceiver(mUsbReceiver, filter);
Iterator<UsbDevice> usbDeviceIter = usbDevices.iterator();
while(usbDeviceIter.hasNext())
{
if (USBDeviceValid(usbDevice))
{
// Request permission to access the device.
mUsbManager.requestPermission(usbDevice, mPermissionIntent);
// Open the device.
UsbDeviceConnection connection = mUsbManager.openDevice(usbDevice);
int fd = connection.getFileDescriptor();
// Now pass the file descriptor to libusb through a native call.
}
}
编辑2：
获得libusb的建立只是把文件放在方便（我把它们放在JNI/libusb的），然后添加以下行到你的Android.mk的事情：
include $(CLEAR_VARS)
LOCAL_MODULE := libusb
LOCAL_SRC_FILES := libusb/core.c libusb/descriptor.c libusb/io.c libusb/sync.c libusb/os/linux_usbfs.c
LOCAL_LDLIBS := -llog
include $(BUILD_SHARED_LIBRARY)
我可以在某处找到创建和传递设备描述符。 – highsciguy 2013-04-26 10:31:35
@highsciguy：发布编辑。 – Goz 2013-04-26 11:08:10
@highsciguy：这有帮助吗？ – Goz 2013-04-26 19:29:39
即使你编译了它，Android可能也不会让你通过libusb访问USB设备，除非你的设备是根植的。如果将应用程序移植到Android's native USB stack是可行的，那几乎肯定会是更稳定的解决方案。
设备已生根。对于所有其他具有最新固件的Rikomagic III HDMI支架也是如此。如果这是不使用libusb的唯一原因，我会试一试。但是，知道类似Android的USB堆栈和libusb是多么的有趣，如果你对它有所了解......另外：我怎样才能在C中使用它。 – highsciguy 2013-04-26 08:27:37
你也可以尝试使用android serial port api
这里是串口init的例子。
private FileDescriptor mFd;
private FileInputStream mFileInputStream;
private FileOutputStream mFileOutputStream;
public SerialPort(File device, int baudrate, int flags) throws SecurityException, IOException {
/* Check access permission */
if (!device.canRead() || !device.canWrite()) {
try {
/* Missing read/write permission, trying to chmod the file */
Process su;
su = Runtime.getRuntime().exec("/system/bin/su");
String cmd = "chmod 666 " + device.getAbsolutePath() + "\n"
+ "exit\n";
su.getOutputStream().write(cmd.getBytes());
if ((su.waitFor() != 0) || !device.canRead()
|| !device.canWrite()) {
throw new SecurityException();
}
} catch (Exception e) {
e.printStackTrace();
throw new SecurityException();
}
}
mFd = open("/dev/ttyACM0", 9600, 0);
if (mFd == null) {
Log.e(TAG, "native open returns null");
throw new IOException();
}
mFileInputStream = new FileInputStream(mFd);
mFileOutputStream = new FileOutputStream(mFd);
}
在USB主机上使用设备也是如此。
我实现的解决方案是使用Java API打开USB设备，然后使用带有libusb的文件描述符。我由PrimeSense的（https://github.com/OpenNI/OpenNI2）使用的libusb从openni项目
码位：
int LibUsbAndroid::android_open(libusb_device *device, libusb_device_handle **devHandle)
{
int fd = USBJNICallbacks::getCallback()->getDeviceFd(device->bus_number, device->device_address);
__android_log_print(ANDROID_LOG_VERBOSE,"USB","Got FD:%d",fd);
if(fd==-1)
{
__android_log_print(ANDROID_LOG_ERROR,"USB","android_open, bad fd");
return -1;
}
return libusb_open(device, devHandle, fd);
}
public int getDeviceFd(int busNumber, int deviceAddress) {
UsbDevice device = findDevice(busNumber, deviceAddress);
if(device!=null)
{
mReceivedPermission = false;
PermissionRequester pr = new PermissionRequester(device);
pr.run();
if(!mUsbManager.hasPermission(device))
{
Log.v("USB", "Requesting permissiom to device");
mPermissionIntent = PendingIntent.getBroadcast(mContext, 0, new Intent(ACTION_USB_PERMISSION), 0);
IntentFilter filterPermission = new IntentFilter(ACTION_USB_PERMISSION);
mContext.registerReceiver(mUsbPermissionReceiver, filterPermission);
mUsbManager.requestPermission(device, mPermissionIntent);
}
else
{
Log.v("USB", "Already has permission");
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
mReceivedPermission = true;
Log.v("USB", "Opening device");
OpenDevice od = openDevice(device);
Log.v("USB", "Adding to open devices");
mOpenDevices.put(""+busNumber+"/"+deviceAddress, od);
}
Log.v("USB", "Waiting for permission");
waitForPermissionResult();
OpenDevice od = mOpenDevices.get(""+busNumber+"/"+deviceAddress);
if(od!=null)
{
Log.v("USB", "Getting FD");
int result = od.mConnection.getFileDescriptor();
Log.i("USB","USB File desc:"+result);
return result;
}
else
{
Log.v("USB", "Error getting FD");
return -1;
}
}
return -1;
}
private BroadcastReceiver mUsbPermissionReceiver = new BroadcastReceiver（）{
@Override
public void onReceive(Context context, Intent intent) {
Log.v("USB", "Received permission result");
String action = intent.getAction();
if (ACTION_USB_PERMISSION.equals(action)) {
synchronized (this) {
UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
Log.v("USB", "Received permission result OK");
if(device != null){
Log.v("USB", "Device OK");
mContext.unregisterReceiver(this);
Log.v("USB", "Openning device");
OpenDevice od = openDevice(device);
Log.v("USB", "Adding to open device list");
mOpenDevices.put(""+od.mBus+"/"+od.mAddress,od);
Log.v("USB", "Received permission is true");
mReceivedPermission = true;
}
else {
Log.d(TAG, "permission denied for device " + device);
}
}
}
}
}
};
public OpenDevice openDevice(UsbDevice device) {
UsbDeviceConnection connection = mUsbManager.openDevice(device);
Log.i("USB","Device name="+device.getDeviceName());
int bus = getBusNumber(device.getDeviceName());
int address = getAddress(device.getDeviceName());
return new OpenDevice(device, connection, bus, address);
}
int API_EXPORTED libusb_open(libusb_device *dev,
libusb_device_handle **handle, int fd)
{
struct libusb_context *ctx = DEVICE_CTX(dev);
struct libusb_device_handle *_handle;
size_t priv_size = usbi_backend->device_handle_priv_size;
int r;
usbi_dbg("open %d.%d", dev->bus_number, dev->device_address);
_handle = malloc(sizeof(*_handle) + priv_size);
if (!_handle)
return LIBUSB_ERROR_NO_MEM;
r = usbi_mutex_init(&_handle->lock, NULL);
if (r) {
free(_handle);
return LIBUSB_ERROR_OTHER;
}
_handle->dev = libusb_ref_device(dev);
_handle->claimed_interfaces = 0;
memset(&_handle->os_priv, 0, priv_size);
r = usbi_backend->open(_handle,fd);
if (r < 0) {
usbi_dbg("open %d.%d returns %d", dev->bus_number, dev->device_address, r);
libusb_unref_device(dev);
usbi_mutex_destroy(&_handle->lock);
free(_handle);
return r;
}
usbi_mutex_lock(&ctx->open_devs_lock);
list_add(&_handle->list, &ctx->open_devs);
usbi_mutex_unlock(&ctx->open_devs_lock);
*handle = _handle;
/* At this point, we want to interrupt any existing event handlers so
* that they realise the addition of the new device's poll fd. One
* example when this is desirable is if the user is running a separate
* dedicated libusb events handling thread, which is running with a long
* or infinite timeout. We want to interrupt that iteration of the loop,
* so that it picks up the new fd, and then continues. */
usbi_fd_notification(ctx);
return 0;
}
static int op_open(struct libusb_device_handle *handle, int fd)
{
struct linux_device_handle_priv *hpriv = _device_handle_priv(handle);
char filename[PATH_MAX];
_get_usbfs_path(handle->dev, filename);
usbi_dbg("opening %s", filename);
hpriv->fd = fd;
if (hpriv->fd < 0) {
if (errno == EACCES) {
usbi_err(HANDLE_CTX(handle), "libusb couldn't open USB device %s: "
"Permission denied.", filename);
usbi_err(HANDLE_CTX(handle),
"libusb requires write access to USB device nodes.");
return LIBUSB_ERROR_ACCESS;
} else if (errno == ENOENT) {
usbi_err(HANDLE_CTX(handle), "libusb couldn't open USB device %s: "
"No such file or directory.", filename);
return LIBUSB_ERROR_NO_DEVICE;
} else {
usbi_err(HANDLE_CTX(handle),
"open failed, code %d errno %d", hpriv->fd, errno);
return LIBUSB_ERROR_IO;
}
}
return usbi_add_pollfd(HANDLE_CTX(handle), hpriv->fd, POLLOUT);
}
谢谢，这很有帮助。您还可以分享如何创建调用libusb_open（）所需的libusb_device *？ – rsp1984 2016-10-22 15:45:34
这里有一个项目叫libusbdroid http://sourceforge.net/projects/libusbdroid/。我将如何链接sispmctl并进行安装？ – highsciguy 2013-04-19 12:36:43