我正在尝试与使用 HID 接口编程的嵌入式系统进行通信。我收到此错误：
线程“主”org.usb4java.LibUsbException 中的异常：USB 错误 0：无法检查内核驱动程序是否处于活动状态：com.fabioang.usbcustomhid.USB_CustomHID.main（USB_CustomHID.java:157）成功
使用以下代码
import java.util.*;
import java.nio.ByteBuffer;
import org.usb4java.Device;
import org.usb4java.DeviceDescriptor;
import org.usb4java.DeviceHandle;
import org.usb4java.DeviceList;
import org.usb4java.LibUsb;
import org.usb4java.LibUsbException;
/**
* @author Fabio
*
*/
public class USB_CustomHID
{
/** The vendor ID of the custom HID. */
private static final short VENDOR_ID = 0x0483;
/** The product ID of the custom HID. */
private static final short PRODUCT_ID = 0x5750;
/** The USB communication timeout. */
private static final int TIMEOUT = 1000;
/**
* Searches for the custom HID and returns it. If there are
* multiple ones attached then this simple demo only returns
* the first one.
*
* @return The custom HID USB device or null if not found.
*/
public static Device findCustomHID()
{
// Read the USB device list
DeviceList list = new DeviceList();
int result = LibUsb.getDeviceList(null, list);
if (result < 0)
{
throw new RuntimeException(
"Unable to get device list. Result=" + result);
}
try
{
// Iterate over all devices and scan for the custom HID
for (Device device: list)
{
DeviceDescriptor descriptor = new DeviceDescriptor();
result = LibUsb.getDeviceDescriptor(device, descriptor);
if (result < 0)
{
throw new RuntimeException(
"Unable to read device descriptor. Result=" + result);
}
if (descriptor.idVendor() == VENDOR_ID
&& descriptor.idProduct() == PRODUCT_ID) return device;
}
}
finally
{
// Ensure the allocated device list is freed
LibUsb.freeDeviceList(list, false);
}
// No custom HID found
return null;
}
/**
* Sends a message to the custom HID.
*
* @param handle
* The USB device handle.
* @param message
* The message to send.
*/
public static void sendMessage(DeviceHandle handle, byte[] message)
{
ByteBuffer buffer = ByteBuffer.allocateDirect(message.length);
buffer.put(message);
buffer.rewind();
int transfered = LibUsb.controlTransfer(handle,
(byte) (LibUsb.REQUEST_TYPE_CLASS | LibUsb.RECIPIENT_INTERFACE),
(byte) 0x09, (short) 2, (short) 1, buffer, TIMEOUT);
if (transfered < 0)
throw new LibUsbException("Control transfer failed", transfered);
if (transfered != message.length)
throw new RuntimeException("Not all data was sent to device");
}
/**
* Sends a command to the missile launcher.
*
* @param handle
* The USB device handle.
* @param command
* The command to send.
*/
public static void ledControl(DeviceHandle handle, int ledNumber, int ledValue)
{
byte[] message = new byte[64];
message[1] = (byte) (ledNumber);
message[2] = (byte) (ledValue);
sendMessage(handle, message);
}
/**
* @param args
*/
public static void main(String[] args)
{
System.out.println("USB custom HID controller starting...");
// Initialize the libusb context
int result = LibUsb.init(null);
if (result != LibUsb.SUCCESS)
{
throw new LibUsbException("Unable to initialize libusb", result);
}
System.out.println("libusb initialized");
// Search for the custom HID USB device and stop when not found
Device device = findCustomHID();
if (device == null)
{
System.err.println("Custom HID not found.");
System.exit(1);
}
System.out.println("Device found");
// Open the device
DeviceHandle handle = new DeviceHandle();
result = LibUsb.open(device, handle);
if (result != LibUsb.SUCCESS)
{
throw new LibUsbException("Unable to open USB device", result);
}
try
{
System.out.println("Opening device");
// Check if kernel driver is attached to the interface
int attached = LibUsb.kernelDriverActive(handle, 1);
if (attached < 0)
{
throw new LibUsbException(
"Unable to check kernel driver active", result);
}
// Detach kernel driver from interface 0 and 1. This can fail if
// kernel is not attached to the device or operating system
// doesn't support this operation. These cases are ignored here.
result = LibUsb.detachKernelDriver(handle, 1);
if (result != LibUsb.SUCCESS &&
result != LibUsb.ERROR_NOT_SUPPORTED &&
result != LibUsb.ERROR_NOT_FOUND)
{
throw new LibUsbException("Unable to detach kernel driver",
result);
}
// Claim interface
result = LibUsb.claimInterface(handle, 1);
if (result != LibUsb.SUCCESS)
{
throw new LibUsbException("Unable to claim interface", result);
}
// Read commands and execute them
System.out.println("System ready");
ledControl(handle, 1, 1);
// Release the interface
result = LibUsb.releaseInterface(handle, 1);
if (result != LibUsb.SUCCESS)
{
throw new LibUsbException("Unable to release interface",
result);
}
// Re-attach kernel driver if needed
if (attached == 1)
{
LibUsb.attachKernelDriver(handle, 1);
if (result != LibUsb.SUCCESS)
{
throw new LibUsbException(
"Unable to re-attach kernel driver", result);
}
}
System.out.println("Exiting");
}
finally
{
LibUsb.close(handle);
}
// Deinitialize the libusb context
LibUsb.exit(null);
}
}