Hello all,

This is a two parter. One is an error that I'm receiving and one is a question in general about the capabilities of PyUSB.

1) So I've installed libusb from the tar file by just doing ./configure && make && sudo make install and I have checked that the library is in my /usr/local/lib and that my LD_LIBRARY_PATH is looking there. Out of frustration I also did sudo port install libusb as well. In either case I'm receiving this error:

In [1]: import usb.core

In [2]: dev = usb.core.find(find_all=True)
ValueError                                Traceback (most recent call last)
<ipython-input-2-f185198e950d> in <module>()
----> 1 dev = usb.core.find(find_all=True)

/Users/matthewbray/Library/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/usb/core.pyc in find(find_all, backend, custom_match, **args)
    854                 break
    855         else:
--> 856             raise ValueError('No backend available')
    858     k, v = args.keys(), args.values()

ValueError: No backend available

I'm not sure how to get it to see the backend and google isn't really helping me that much.

2) I'm looking to receive information from a thermometer that plugs in through USB (Fluke 568 IR thermometer) and was hoping that I could get the reading through some pyUSB interface. Is that even something that is possible? I was going to just play around with it and see if I could get anything, but I'm unable to even get anything to run as long as it can't find a backend.

Thanks for your time!

I have libusb1.0 installed, but for some reason pyUSB doesn't seem to be able to find it. It seems like it is a Mac problem. I installed it on my Windows machine and it works just fine. I haven't had enough time to play with it to see if it actually has the capabilities I'm looking for though. I still can't get it to recognize any backend on the Mac side.

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