hi the title may busbcom = new UsbCom();
connect(usbcom, SIGNAL(error(QString)), SLOT(usbError(QString)));
usbcom->start();e a little weird but i wasnt sure what to call it.

il try to explain what im trying to do.

i am trying to get data from the usb device with libusb_handle_events function
in my main class i use this code to start the thread for usb communication:
Qt Code: 
  1. usbcom = new UsbCom();
  2.     connect(usbcom, SIGNAL(error(QString)), SLOT(usbError(QString)));
  3.     connect(usbcom, SIGNAL(dataRecieved(QString)), SLOT(usbDataRecieved(QString)));
  4.     usbcom->start();
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UsbCom class:

Qt Code: 
  1. #include "usbcom.h"
  2. #include <QtGui>
  3. #include "/usr/local/include/libusb-1.0/libusb.h"
  4. #include "dataemit.h"
  5. #include <QApplication>
  6.  
  7. #define idVENDOR	0x0483
  8. #define idPRODUCT	0x5750
  9. #define EP_INTR_OUT	( 1 | LIBUSB_ENDPOINT_OUT)
  10. #define EP_INTR_IN	( 1 | LIBUSB_ENDPOINT_IN )
  11.  
  12. UsbCom::UsbCom()
  13. {
  14. }
  15.  
  16. void UsbCom::run()
  17. {
  18.     int r;
  19.     int transf;
  20.     unsigned char data[2]={2,5};
  21.     r = libusb_init(NULL);
  22.     if (r < 0)
  23.     {
  24.         emit error("Failed to initialize USB!");
  25.         exit(1);
  26.     }
  27.  
  28.     libusb_device_handle *devh = libusb_open_device_with_vid_pid(NULL, idVENDOR, idPRODUCT);
  29.  
  30.     if(!devh)
  31.     {
  32.        emit error("Could not locate device");
  33.        exit();
  34.     }
  35.  
  36.     r = libusb_kernel_driver_active (devh, 0);
  37.  
  38.     if (r != 0)
  39.     {
  40.         if(r==1)
  41.         {
  42.             r = libusb_detach_kernel_driver(devh, 0);
  43.             if (r > 0)
  44.             {
  45.                 emit error("some other random error:"+ QString::number(r));
  46.                 exit(1);
  47.             }
  48.         }
  49.     }
  50.  
  51.     r = libusb_claim_interface(devh, 0);
  52.  
  53.     if (r < 0)
  54.     {
  55.         emit error("usb_claim_interface error"+ QString::number(r));
  56.     }
  57.  
  58.     r = libusb_interrupt_transfer(devh, EP_INTR_OUT, data, sizeof(data), &transf,50);
  59.  
  60.     emit error("did it work? r:" + QString::number(r));
  61.  
  62.     irq_transfer = libusb_alloc_transfer(0);
  63.     unsigned char irqbuf[2];
  64.  
  65.     libusb_fill_interrupt_transfer(irq_transfer, devh, EP_INTR_IN, irqbuf,sizeof(irqbuf), ep_irq_in_cb, NULL, 0);
  66.     r = libusb_submit_transfer(irq_transfer);
  67.  
  68.     while(1)
  69.     {
  70.         r = libusb_handle_events(NULL);        
  71.     }
  72. }
  73.  
  74. void UsbCom::dataRecieve()
  75. {
  76. }
  77.  
  78. void ep_irq_in_cb(libusb_transfer *transfer)
  79. {
  80.     if(transfer->status != LIBUSB_TRANSFER_COMPLETED)
  81.     {
  82.      // fprintf(stderr, "uncompleted transter\n");
  83.     }
  84.  
  85.     //[COLOR="red"]dont know what code goes here, try to call UsbCom::DataRecieve[/COLOR]
  86.  
  87.     if (libusb_submit_transfer(transfer) < 0){
  88.       fprintf(stderr,"couldnot resubmit irq \n");
  89.                 exit(1);
  90.     }
  91.  
  92. }
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the problem is that as you can see the
void ep_irq_in_cb(libusb_transfer *transfer) function is not in the UsbCom class. but when the code executes i need to call the UsbCom:ataRecieve() function so that it connects to the slot in my main thread.

if anyone can help me i would be very gratefull.

Sisco