Help Android Glass? External USB camera?

[d0ugparker]

I've searched, but can find what I want. Similar to Google
Glass, but it's more accurately just a clip-on, tiny, external
USB camera that disables the smartphone's on board cam.

Part of the problem is that there's a lot of overlapping,
doubly defined terms being used like camera, external,
USB, (Google) Glass, and plug-and-play, etc. The watered
down terminology makes it difficult to get a good signal on
things.

Here's what I want, and it's really simple in concept:

LG L80 <---> external USB camera​

so that when I plug the external camera into the phone's
micro-USB connector, it switches the external USB cam on,
and disables the phone's on board camera, or mirrors it.
Disabling it makes more sense, WRT battery.

If the external cam has its own mic, then an option for mic
source would be nice.

It'll be DIY, quick, and inexpensive.

Someone's got to be doing this already. If you've found
helpful threads or URLs, please post them here.

(I wanted to put this in general discussion, but somehow
it seems to have been posted in support. Could someone
move this for me if that's the case?)

Thanks.