Re: [Libusb-win32-devel] usb_bulk_read return -22

[Ze H. Z. <ze....@ma...>]

Hi Xiaofan
I open and received device handler, and be able to use usb_control_msg to
send and receive data.  also checked device interface endpoints, but I
can’t use usb_bulk_read to read big buffer from device which supposed to be
ready
Thanks

On Fri 3 Apr 2020 at 03:28, Xiaofan Chen <xia...@gm...> wrote:

> On Thu, Apr 2, 2020 at 1:00 AM Ze Hou Zhang <ze....@ma...> wrote:
> >
> > Hi All
> > I dont have a lot experience for developping embedded system.
> > I encounter this problem
> > My hardware is :
> >         int vid = 0x24aa;
> >         int pid = 0x1000;
> >         std::string firmwarePartNum = "170003";
> >         std::string firmwareDesc = "FX2 USB Board";
> >         bool isSupported;
> >         unsigned int defaultPixels = 1024;
> >         unsigned int spectraBlockSize = 1024 * 2;
> >         unsigned int usbDelayMS = 0;
> >         bool hasDefaultTECSetpointDegC = false;
> >         int defaultTECSetpointDegC = 0;
> > =============================================================
> >            int size = 512;
> >             char* buf = new char[size];
> >             int endpoint = 130;
> >             int timeout = 150;
> >
> >             int isok = usb_bulk_read(*deviceHandle, endpoint, bytes,
> size, timeout);
> >
> >            Output:  ok = -22
> > Thanks
> >
>
> You have to know the communication protocol of the device in order
> to use libusb-win32. In your case, you need to make sure your device
> is sending data.
>
>
> --
> Xiaofan
>
>
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> Libusb-win32-devel mailing list
> Lib...@li...
> https://lists.sourceforge.net/lists/listinfo/libusb-win32-devel
>

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