wander.lairson <wander.lairson@...> writes: > > 2011/3/15 Xiaofan Chen <xiaofanc@...>: > > On Tue, Mar 15, 2011 at 10:55 PM, Emmanuel Blot <eblot.ml@...> wrote: > >> I need to detach *all* the interfaces from the (Linux) kernel, or I > >> sometime get an error (not a big deal for my use case) > >> I also need to call dev.set_configuration() to configure the device. > >> Nothing unusual I guess. > >> > >> The troubles happen when I need to open two serial ports, that is two > >> interfaces from the same USB device. > >> On the second initialization call, when dev.set_configuration() is > >> called for the second time, the first open interface gets in trouble: > >> Exception: UsbError: No such device (it may have been disconnected) > >> It seems set_configuration() cannot be called another time if an > >> interface is already being actively used. > >> > >> I don't know how to avoid calling set_configuration() more that once, > >> as I don't know how to identify that the USB device has already been > >> configured. > >> > > > > You can call set_configuration() once and then call claim_interface > > for each interface. At least this is how libusb works for USB composite > > device. > > > You can do this through util.claim_interface function. >
Hi Wander, I am trying to communicate with a Lego WeDO device using PyUSB. Right at the beginning when self.dev.is_kernel_driver_active(0) is called, I get the error File "C:\Users\DevTech\workspace\test1\src\WeDoMore.py", line 14, in __init__ if self.dev.is_kernel_driver_active(0): File "C:\Python26\lib\site-packages\usb\core.py", line 687, in is_kernel_driver_active return self._ctx.backend.is_kernel_driver_active(self._ctx.handle, interface) File "C:\Python26\lib\site-packages\usb\backend\__init__.py", line 355, in is_kernel_driver_active _not_implemented(self.is_kernel_driver_active) File "C:\Python26\lib\site-packages\usb\backend\__init__.py", line 79, in _not_implemented raise NotImplementedError(func.__name__) NotImplementedError: is_kernel_driver_active I am running my python code on windows ; is it true that the backend interface is not implemented for windows (including is-kernel-driver-active() function)?? If so,what should I do now? :((( I would appreciate your comment/thoughts very much since it seems you are the one who has put this all together; thank you for doing that. Thanks Safoura ------------------------------------------------------------------------------ EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev _______________________________________________ pyusb-users mailing list pyusb-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pyusb-users