Re: [Libusb-devel] USB error reading USB config strings on Linux

[Brad H. <bh...@bi...>]

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On Thu, 08 Jan 2004 08:03 am, Douglas S. Blank wrote:
> Trying the tests/testlibusb program that comes with libusb-0.1.7, I'm
> able to see the robot USB data somewhat. But I get errors whenever I try
> to read a string (manufacturer, vendor, or serial number).
>
> I've traced it down to the line:
>
> ret =3D ioctl(dev->fd, IOCTL_USB_CONTROL, &ctrl);
>
> in linux.c in the function usb_control_msg() which returns -1 on reading
> the strings (other functions seem to work).
What does usb_strerror() return after this? If it tells you about a permiss=
ion=20
error, are you running the application as root?

> 1. Is this the right project for the job (being that I'm not that
> experienced with USB programming)? Should I consider using usbserial? Or
> something else?
I think libusb can help. It is almost impossible to tell what the protocol =
is=20
without usbsnoopy under Windows, or the vendor's information on the protoco=
l.

> 2. If this is the right project, can someone help with the above error?
See above.

> 3. Where do I go from here?
Ask the vendor for the protocol?

Brad
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http://linux.conf.au - I'm registered. Are you?
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