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发表于 2015-4-24 08:57:01
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android 下用libusb开发USB设备是件很酸爽的事情,不需要ROOT,不需要修改KERNEL. 直接在应用层操作usb,就可以和和带USB的单片机通讯。 我们的DTV Dongle就是这样做的。需要注意的是,USB设备访问权限需要APK获取并传递给LIBUSB , 然后libusb需要做点小的修改,参考代码如下:
int API_EXPORTED libusb_open_fd(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_fd(_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;
} |
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