Re: [Libusb-win32-devel] devices list is empty on Windows x64

[Xiaofan C. <xia...@gm...>]

On Mon, Apr 11, 2011 at 7:22 PM, Martin K <mar...@gm...> wrote:
> On Sat, Apr 9, 2011 at 7:42 PM, Xiaofan Chen <xia...@gm...> wrote:
>> As for "unknown device", it can be hardware or firmware problem.
>> Please post to Microchip forum here for more help. You
>> may need to post your schematics there for hardware check.
>> http://www.microchip.com/forums/f102.aspx
>>
> I believe it's safe to say that "unknown device" is a firmware
> problem. It's not communicating at all, but the computer knows
> something is there (pullups)

This may not be true. "Unknown device" can well be a hardware
problem, for example, the clock is not stable or things like that.
Actually in the Microchip forum, the No 1 enumeration problem
for USB PIC18 is to forget about the Vusb capacitor (typically
470nF), No 2 being the improper clock configuration.

Reference:
http://www.microchip.com/forums/fb.ashx?m=335717

-- 
Xiaofan