[techhelpbb]

Originally Posted by virtuald

Hm, so it definitely looks like the lifecam devices don't have serial numbers or unique identifiers of any kind on them. There are symlinks setup at /dev/v4l/by-id and /dev/v4l/by-path. As you might imagine, the by-id symlinks are useless (only one appears even with multiple devices plugged in), but the by-path symlinks appear to be related to the position on the USB hub, and the information I've found appears to indicate that it should be a stable path.

Initial experiments on a roborio with a hub indicate that the by-path positions are indeed stable across device insert/removals and reboots. I'm not 100% sure of the best way to test this, but I'll add the information to mjpg-streamer's documentation anyways.

Could put a queue in the image (dots on lens or card in field of vision with image or color you could detect with code) or put a relay on the USB wires and connect the cameras one at a time then check the relay output against the device names that appear.

Does this help?
http://superuser.com/questions/74803...ng-usb-devices