2013/7/17 Elizabeth Tolman <etol...@princeton.edu>:
> Hello,
>
> I'm new to pyusb and to working with usb devices in general. I'm trying to
> read voltage data from a Tenma 72-7732 multimeter, but I'm having some
> problems. This is my code so far:
>
> def main():
> import usb.core
> import usb.util
> import usb.backend
>
> #find device
>
> dev = usb.core.find(idVendor=0x1a86, idProduct=0xe008)
>
> # did you find it?
> if dev is None:
> raise ValueError('Device not found')
> else:
> print "Device found"
>
>
> dev.set_configuration()
>
>
> endpoint = dev[0][(0,0)][0]
>
>
> data = dev.read(endpoint.bEndpointAddress, endpoint.wMaxPacketSize, 0,
> 100000)
>
> print data
>
>
> main()
>
>
> This finds the device, but gives a timeout error when it tries to read data.
> Do you have any idea what might have gone wrong? The multimeter has very
> poor documentation, so I can't go there for advice.
>
Hi,
What operating system are you using? If *nix, could please use lsusb
to show us your device topology? Also, you can try the
PYUSB_DEBUG_LEVEL=debug environment variable and paste the output
here. Just do "export PYUSB_DEBUG_LEVEL=debug" on command prompt.
Details here [1]
[1] https://github.com/walac/pyusb/blob/master/docs/tutorial.rst
--
Best Regards,
Wander Lairson Costa
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