On Sun, Apr 24, 2022 at 8:43 AM stuart lynne <stuart.ly...@gmail.com> wrote: > > I am seeing a consistent issue with Garmin Ant+ dongles under Windows with > libusb0. > > They work the first time my application runs, but fail on the second attempt. > > I have verified the same behaviour across three Garmin Dongles. I have > verified > that the Cycplus Dongle works correctly. > > To maintain compatibility with the other applications running (Zwift and > PerfPro > CT Smart) which rely on libusb0 I need to use that backend. > > Those applications do not have any problems with the Garmin (or Cycplus) > dongles, using them multiple times without a problem. > > Is it possible that I need to do something on exit that might cause this? > > Is there anything I can do to remediate this when seen? >
Does it make a difference if you use the libusb-1.0 backend? This is not a solution but rather a troubleshooting step. You can keep your driver as it is, but switch to libusb-1.0 backend. You need to have libusbk.dll and libusb-1.0.dll in place to make that work. I understand that you may have to keep with the libusb0.sys based driver provided by Garmin (I used to have one such USB dongle for my old Garmin Vivofit 1). The other potential work-around is to add a device reset at exit. Usually this kind of issue is caused by device firmware bug (eg: USB data toggle issues) and the hope is that the device reset can put the firmware to a good state. -- Xiaofan _______________________________________________ pyusb-users mailing list pyusb-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pyusb-users
