I have the LibUSB-Win32 installed and the test program is connected to my Zebra KR403 printer and I can see the configuration info for the printer so I think my driver package is ok. I am curious though about the libusb0.dll. I see that it is installed in C:\Windows\System32\Config\ and I do not think my program is looking for it there. I put a copy of the dll file in the root of System32 and my program now works on my target PC.
-----Original Message----- From: Wander Lairson Costa [mailto:wander.lair...@gmail.com] Sent: Thursday, June 11, 2015 20:31 To: pyusb-users Subject: Re: [pyusb-users] question 2015-06-11 16:44 GMT-03:00 Jay Newens <j...@nemo-q.com>: > I am using pyusb in my Python 2.7 environment getting the status of > the Zebra KR403 printer and having good success on a Windows 7 64 bit > PC. Now I am ready to test this on my target machine. I have created > my executable program with py2exe and tested the exe on my development > PC and it works fine but when I move it to my target PC I get a > message “No Backend Available” when it gets to the “dev = > usb.core.find(idVendor=int(VID), idProduct=int(PID))” part of my code. > I convert the hex to an integer here but when using the hex value I > get the same issue on my target PC, even with hex value, both hex and > converting to integer work fine on the development PC so I do not think the > issue is here. > PyUSB on Windows depends either of libusb 1.0 or libusb-win32. Contrary to the unices version, libusb on Windows needs to attach as a device driver. You can use zadig to install libusb (or libusb-win32) driver for your device. libusb uses the WinUSB driver (which is shipped with Windows). If you want to redistribute your software to users, you will have to provide a driver package to the user (basically writing an inf file and ship the binaries). However, giving details on how to do that is out of scope of this mailing list. OSR [1] can be helpful here [1] http://www.osronline.com/ > > > Traceback (most recent call last): > > File "ZebraKR403PaperStatus1.0.py", line 98, in <module> > > File "usb\core.pyc", line 846, in find > > ValueError: No backend available > > > > I am not sure what is causing the issue. It seems as though there is a > missing dll or something that is required to make this work and it did > not make it to my target PC. Any suggestions or ideas what I may be > missing would be greatly appreciated. > > > > > > Jay > > > > > > > > > > > > > ---------------------------------------------------------------------- > -------- > > _______________________________________________ > pyusb-users mailing list > pyusb-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/pyusb-users > -- Best Regards, Wander Lairson Costa ------------------------------------------------------------------------------ _______________________________________________ pyusb-users mailing list pyusb-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pyusb-users ------------------------------------------------------------------------------ _______________________________________________ pyusb-users mailing list pyusb-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pyusb-users
