Originally Posted by PeterT
It should work at any time.... Oh well.... so much for that idea
I had a look at the code. It looks like it is querying the current USB bus. But, there must be some filtering I am missing as it is only reporting readers. I suspect if a device that calibre didn't know about was plugged in, it wouldn't report it.
I think the calibre device detection is the best method. It not only reports the ids but it also reports what calibre thinks the device is.