Re: Win 7 Device Manager displays Unknown Device
Xiaofan Chen <[email protected]>
| Newsgroups | gmane.comp.lib.libusb.devel.windows |
|---|---|
| Message-ID | <CAGjSPUDLYugNzF+G+8Z9n4gadnP9iG_rbKPOmLoBqs7YrHWAZw@mail.gmail.com> |
On Sat, May 10, 2014 at 1:33 AM, Kevin Lee <[email protected]> wrote: > Hi All, > > Our device uses libusb-win32 to connect to a PC, but we’ve > recently encountered an odd obstacle. > > On two Windows 7 Pro SP1 computers (with an Intel 64 Family 6, > Model 58, Stepping 9 chipset), the Device Manager simply displays > unknown device and we cannot communicate with the device. > We have installed the drivers correctly, but there was no change. > We also attempted to use the Add Hardware Wizard to manually > point to the driver package, which created an item under libusb-win32 > with the correct device, but it did not seem to be linked to the actual > hardware. The “unknown device” was still there, and our software > still failed to communicate with the hardware. > > Is there something obvious I’m missing? We’ve successfully > had the system work with a similar Win7 AMD64 computer. If Windows recognize the device as "unknown device", then there is nothing libusb-win32 can do. This is known as an enumeration problem, most like a device firmware (or hardware stability) problem which got exposed by the new computer. You can try to use a hardware USB analyzer. Or you can try Windows ETW function here. http://msdn.microsoft.com/en-us/library/windows/hardware/jj151572(v=vs.85).aspx http://blogs.msdn.com/b/usbcoreblog/archive/2009/10/31/how-does-usb-stack-enumerate-a-device.aspx -- Xiaofan ------------------------------------------------------------------------------ Is your legacy SCM system holding you back? Join Perforce May 7 to find out: • 3 signs your SCM is hindering your productivity • Requirements for releasing software faster • Expert tips and advice for migrating your SCM now http://p.sf.net/sfu/perforce _______________________________________________ Libusb-win32-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libusb-win32-devel