libusb 示例

 #include <usb.h>
 #include <stdio.h>

 #define VERSION "0.1.0"
 #define VENDOR_ID 0x0925
 #define PRODUCT_ID 0x7001
 #define INTERFACE 0
 const static int reqIntLen=;
 const static int endpoint_Int_in=0x81; /* endpoint 0x81 address for IN */
 const static int endpoint_Int_out=0x01; /* endpoint 1 address for OUT */

 const static int timeout=; /* timeout in ms */

 void bad(const char *why) {
   fprintf(stderr,"Fatal error> %s\n",why);
   exit();
 }

 usb_dev_handle *find_lvr_hid();

 usb_dev_handle* setup_libusb_access() {
     usb_dev_handle *lvr_hid;
     int retval;
     char dname[] = {};
     usb_set_debug();
     usb_init();
     usb_find_busses();
     usb_find_devices();

     if(!(lvr_hid = find_lvr_hid())) {
     printf("Couldn't find the USB device, Exiting\n");
     return NULL;
   }

 #ifdef LINUX
   retval = usb_get_driver_np(lvr_hid, , dname, );
   if (!retval)
     usb_detach_kernel_driver_np(lvr_hid, );

 #endif

   retval=usb_set_configuration(lvr_hid, );
   if ( retval < ) {
     printf("Could not set configuration 1 : %d\n", retval);
     return NULL;
   }
   retval = retval=usb_claim_interface(lvr_hid, INTERFACE);
   if ( retval < ) {
     printf("Could not claim interface: %d\n", retval);
     return NULL;
   }

   return lvr_hid;
 }

 usb_dev_handle *find_lvr_hid()
 {
     struct usb_bus *bus;
   struct usb_device *dev;

   for (bus = usb_get_busses(); bus; bus = bus->next) {
       for (dev = bus->devices; dev; dev = dev->next) {
         if (dev->descriptor.idVendor == VENDOR_ID &&
           dev->descriptor.idProduct == PRODUCT_ID ) {
         usb_dev_handle *handle;
           printf("lvr_hid with Vendor Id: %x and Product Id: %x found.\n", VENDOR_ID, PRODUCT_ID);
         if (!(handle = usb_open(dev))) {
           printf("Could not open USB device\n");
           return NULL;
         }

         return handle;
       }

     }
   }

   return NULL;
 }

 /*
  void test_control_transfer(usb_dev_handle *dev)
  {
 //   usb_set_altinterface(dev, 0);
    usb_release_interface(dev, 0);
  }
 */
  void test_interrupt_transfer(usb_dev_handle *dev)
  {
    int r,i;
    char answer[reqIntLen];
    char question[reqIntLen];
    for (i=;i<reqIntLen; i++) question[i]=i;
    r = usb_interrupt_write(dev, endpoint_Int_out, question, reqIntLen, timeout);
    if( r <  )
    {
     perror("USB interrupt write"); bad("USB write failed");
    }
    r = usb_interrupt_read(dev, endpoint_Int_in, answer, reqIntLen, timeout);
    if( r != reqIntLen )
    {
     perror("USB interrupt read"); bad("USB read failed");
    }
    for (i=;i<reqIntLen; i++) printf("%i, %i, \n",question[i],answer[i]);
 //   usb_set_altinterface(dev, 0);
    usb_release_interface(dev, );
  }

 int main( int argc, char **argv)
 {
   usb_dev_handle *lvr_hid;
   if ((lvr_hid = setup_libusb_access()) == NULL) {
     exit(-);
   }
 //  test_control_transfer(lvr_hid); //not implemented yet
   test_interrupt_transfer(lvr_hid);
   usb_close(lvr_hid);

   return ;
 }