RTLSDR only works on Windows if the WinUSB driver is installed

[darksidelemm]

If you try using a RTLSDR on windows and the WinUSB drivers hasn't been installed, everything seems to go OK, but no samples are received (dBFS sits at -999, spectrum plot doesn't update, etc). Otherwise no errors are displayed.

Recommend adding a note on the page somewhere pointing users to a WinUSB installer like Zadig: https://zadig.akeo.ie/
The same driver is needed to use RTLSDR on Windows with other applications like SDR++, SDR#, etc, so if the users already has a RTLSDR working with those apps, they probably won't see this issue.

Given the symptoms, it may also be possible to pick up this error state some other way and warn the user.

[TheSkorm]

Put a crude warning on the home page. I'll leave this ticket open as we should detect if the browser is running under windows + if we can't start the radio.