[pyusb-users] No backend available with windows 7

Brought to you by: jonasmalaco, rwlodarczyk, tormod, wander_lairson, xiaofanc

[pyusb-users] No backend available with windows 7

[pyusb-users] No backend available with windows 7

From: Michel A. <mic...@vi...> - 2015-03-02 05:06:11

Hi,

 

In my current project I must communicate through the USB bus with several
micro controllers which are USB ready.

 

I want to do this in Python running on Windows 7-64bits.

 

PyUSB 1.0.0b2  is installed as well as libusb-win32 (
libusb-win32-devel-filter-1.2.6.0.exe was used without adding a filter for a
particular device)

 

The file libusb0.dll is present in C:\Windows\System32\  and the file
libusb0.sys is present in C:\Windows\System32\drivers\.

 

 

My test script is the following

 

import os

os.environ['PYUSB_DEBUG']='debug'

os.environ['PYUSB_LOG_FILENAME']="D:\LOG_ERR_TEST.txt"

 

import usb.core

import usb.util

 

dev = usb.core.find(find_all = True)

 

 

 

 

And it produces the following error:

 

Traceback (most recent call last):

  File "C:\Python34\Test PYUSB.py", line 13, in <module>

    dev = usb.core.find(find_all = True)

  File "C:\Python34\usb\core.py", line 1219, in find

    raise ValueError('No backend available')

ValueError: No backend available

 

 

The error log file goes like this:

 

2015-02-27 22:22:24,995 ERROR:usb.libloader:'Libusb 1' could not be found

2015-02-27 22:22:24,996 ERROR:usb.backend.libusb1:Error loading libusb 1.0
backend

2015-02-27 22:22:25,000 ERROR:usb.libloader:'OpenUSB library' could not be
found

2015-02-27 22:22:25,001 ERROR:usb.backend.openusb:Error loading OpenUSB
backend

2015-02-27 22:22:25,012 ERROR:usb.libloader:Libusb 0
(C:\WinAVR-20100110\bin\libusb0.dll) could not be loaded

Traceback (most recent call last):

  File "C:\Python34\usb\libloader.py", line 116, in load_library

    return ctypes.CDLL(lib)

  File "C:\Python34\lib\ctypes\__init__.py", line 351, in __init__

    self._handle = _dlopen(self._name, mode)

OSError: [WinError 193] %1 n'est pas une application Win32 valide (in
English : "not a valid Win32 application")

2015-02-27 22:22:25,013 ERROR:usb.backend.libusb0:Error loading libusb 0.1
backend

2015-02-27 22:25:16,570 ERROR:usb.libloader:'Libusb 1' could not be found

2015-02-27 22:25:16,571 ERROR:usb.backend.libusb1:Error loading libusb 1.0
backend

2015-02-27 22:25:16,575 ERROR:usb.libloader:'OpenUSB library' could not be
found

2015-02-27 22:25:16,576 ERROR:usb.backend.openusb:Error loading OpenUSB
backend

2015-02-27 22:25:16,586 ERROR:usb.libloader:Libusb 0
(C:\WinAVR-20100110\bin\libusb0.dll) could not be loaded

Traceback (most recent call last):

  File "C:\Python34\usb\libloader.py", line 116, in load_library

    return ctypes.CDLL(lib)

  File "C:\Python34\lib\ctypes\__init__.py", line 351, in __init__

    self._handle = _dlopen(self._name, mode)

OSError: [WinError 193] %1 n'est pas une application Win32 valide   (in
English : "not a valid Win32 application")

2015-02-27 22:25:16,588 ERROR:usb.backend.libusb0:Error loading libusb 0.1
backend

2015-02-27 22:35:31,821 ERROR:usb.libloader:'Libusb 1' could not be found

2015-02-27 22:35:31,822 ERROR:usb.backend.libusb1:Error loading libusb 1.0
backend

2015-02-27 22:35:31,827 ERROR:usb.libloader:'OpenUSB library' could not be
found

2015-02-27 22:35:31,827 ERROR:usb.backend.openusb:Error loading OpenUSB
backend

2015-02-27 22:35:31,838 ERROR:usb.libloader:Libusb 0
(C:\WinAVR-20100110\bin\libusb0.dll) could not be loaded

Traceback (most recent call last):

  File "C:\Python34\usb\libloader.py", line 116, in load_library

    return ctypes.CDLL(lib)

  File "C:\Python34\lib\ctypes\__init__.py", line 351, in __init__

    self._handle = _dlopen(self._name, mode)

OSError: [WinError 193] %1 n'est pas une application Win32 valide (in
English : "not a valid Win32 application")

2015-02-27 22:35:31,840 ERROR:usb.backend.libusb0:Error loading libusb 0.1
backend

2015-02-27 22:40:53,266 ERROR:usb.libloader:'Libusb 1' could not be found

2015-02-27 22:40:53,267 ERROR:usb.backend.libusb1:Error loading libusb 1.0
backend

2015-02-27 22:40:53,272 ERROR:usb.libloader:'OpenUSB library' could not be
found

2015-02-27 22:40:53,272 ERROR:usb.backend.openusb:Error loading OpenUSB
backend

2015-02-27 22:40:53,282 ERROR:usb.libloader:Libusb 0
(C:\WinAVR-20100110\bin\libusb0.dll) could not be loaded

Traceback (most recent call last):

  File "C:\Python34\usb\libloader.py", line 116, in load_library

    return ctypes.CDLL(lib)

  File "C:\Python34\lib\ctypes\__init__.py", line 351, in __init__

    self._handle = _dlopen(self._name, mode)

OSError: [WinError 193] %1 n'est pas une application Win32 valide

2015-02-27 22:40:53,284 ERROR:usb.backend.libusb0:Error loading libusb 0.1
backend

2015-02-27 22:41:37,963 ERROR:usb.libloader:'Libusb 1' could not be found

2015-02-27 22:41:37,964 ERROR:usb.backend.libusb1:Error loading libusb 1.0
backend

2015-02-27 22:41:37,969 ERROR:usb.libloader:'OpenUSB library' could not be
found

2015-02-27 22:41:37,969 ERROR:usb.backend.openusb:Error loading OpenUSB
backend

2015-02-27 22:41:37,979 ERROR:usb.libloader:Libusb 0
(C:\WinAVR-20100110\bin\libusb0.dll) could not be loaded

Traceback (most recent call last):

  File "C:\Python34\usb\libloader.py", line 116, in load_library

    return ctypes.CDLL(lib)

  File "C:\Python34\lib\ctypes\__init__.py", line 351, in __init__

    self._handle = _dlopen(self._name, mode)

OSError: [WinError 193] %1 n'est pas une application Win32 valide (in
English : "not a valid Win32 application")

2015-02-27 22:41:37,981 ERROR:usb.backend.libusb0:Error loading libusb 0.1
backend

2015-02-27 22:42:38,367 ERROR:usb.libloader:'Libusb 1' could not be found

2015-02-27 22:42:38,368 ERROR:usb.backend.libusb1:Error loading libusb 1.0
backend

2015-02-27 22:42:38,372 ERROR:usb.libloader:'OpenUSB library' could not be
found

2015-02-27 22:42:38,373 ERROR:usb.backend.openusb:Error loading OpenUSB
backend

2015-02-27 22:42:38,383 ERROR:usb.libloader:Libusb 0
(C:\WinAVR-20100110\bin\libusb0.dll) could not be loaded

Traceback (most recent call last):

  File "C:\Python34\usb\libloader.py", line 116, in load_library

    return ctypes.CDLL(lib)

  File "C:\Python34\lib\ctypes\__init__.py", line 351, in __init__

    self._handle = _dlopen(self._name, mode)

OSError: [WinError 193] %1 n'est pas une application Win32 valide

2015-02-27 22:42:38,384 ERROR:usb.backend.libusb0:Error loading libusb 0.1
backend

2015-02-28 12:23:20,858 ERROR:usb.libloader:'Libusb 1' could not be found

2015-02-28 12:23:20,858 ERROR:usb.backend.libusb1:Error loading libusb 1.0
backend

2015-02-28 12:23:20,858 ERROR:usb.libloader:'OpenUSB library' could not be
found

2015-02-28 12:23:20,858 ERROR:usb.backend.openusb:Error loading OpenUSB
backend

2015-02-28 12:23:20,858 ERROR:usb.libloader:Libusb 0
(C:\WinAVR-20100110\bin\libusb0.dll) could not be loaded

Traceback (most recent call last):

  File "C:\Python34\usb\libloader.py", line 116, in load_library

    return ctypes.CDLL(lib)

  File "C:\Python34\lib\ctypes\__init__.py", line 351, in __init__

    self._handle = _dlopen(self._name, mode)

OSError: [WinError 193] %1 n'est pas une application Win32 valide (in
English : "not a valid Win32 application")

2015-02-28 12:23:20,878 ERROR:usb.backend.libusb0:Error loading libusb 0.1
backend

2015-02-28 16:51:36,357 ERROR:usb.libloader:'Libusb 1' could not be found

2015-02-28 16:51:36,367 ERROR:usb.backend.libusb1:Error loading libusb 1.0
backend

2015-02-28 16:51:36,367 ERROR:usb.libloader:'OpenUSB library' could not be
found

2015-02-28 16:51:36,367 ERROR:usb.backend.openusb:Error loading OpenUSB
backend

2015-02-28 16:51:36,367 ERROR:usb.libloader:Libusb 0
(C:\WinAVR-20100110\bin\libusb0.dll) could not be loaded

Traceback (most recent call last):

  File "C:\Python34\usb\libloader.py", line 116, in load_library

    return ctypes.CDLL(lib)

  File "C:\Python34\lib\ctypes\__init__.py", line 351, in __init__

    self._handle = _dlopen(self._name, mode)

OSError: [WinError 193] %1 n'est pas une application Win32 valide (in
English : "not a valid Win32 application")

2015-02-28 16:51:36,367 ERROR:usb.backend.libusb0:Error loading libusb 0.1
backend

 

 

Can you help me solve this problem?

 

Thanking you in advance

 

 

Michel Allaire

View entire thread