Re: [pyusb-users] No backend error, please help

[Wander L. C. <wan...@gm...>]

2011/12/20 JA <met...@gm...>

> Ok I understand now. Here is the log -
>
> 2011-12-20 11:14:03,615 ERROR:usb.backend.libusb10:Error loading
> libusb 1.0 backend
> Traceback (most recent call last):
>  File "C:\Python27\lib\site-packages\usb\backend\libusb10.py", line
> 648, in get_backend
>    _lib = _load_library()
>  File "C:\Python27\lib\site-packages\usb\backend\libusb10.py", line
> 198, in _load_library
>    l = WinDLL(libname)
>  File "C:\Python27\lib\ctypes\__init__.py", line 353, in __init__
>    self._handle = _dlopen(self._name, mode)
> TypeError: expected string or Unicode object, NoneType found
> 2011-12-20 11:14:03,670 ERROR:usb.backend.openusb:Error loading OpenUSB
> backend
> Traceback (most recent call last):
>  File "C:\Python27\lib\site-packages\usb\backend\openusb.py", line
> 701, in get_backend
>    _lib = _load_library()
>  File "C:\Python27\lib\site-packages\usb\backend\openusb.py", line
> 248, in _load_library
>    raise OSError('USB library could not be found')
> OSError: USB library could not be found
> 2011-12-20 11:14:03,686 ERROR:usb.backend.libusb01:Error loading
> libusb 0.1 backend
> Traceback (most recent call last):
>  File "C:\Python27\lib\site-packages\usb\backend\libusb01.py", line
> 576, in get_backend
>    _lib = _load_library()
>  File "C:\Python27\lib\site-packages\usb\backend\libusb01.py", line
> 201, in _load_library
>    return CDLL(libname)
>  File "C:\Python27\lib\ctypes\__init__.py", line 353, in __init__
>    self._handle = _dlopen(self._name, mode)
> TypeError: expected string or Unicode object, NoneType found
>
>
It feels like the libusb DLL was not found. Can you tell where it is
located?

-- 
Best Regards,
Wander Lairson Costa