Raspberry Pi Forums

I am looking for a way to keep my USB devices on the same reference number regardless of if I hot-swap the unit or plug it into a physically different port.

I am running two different USB sound cards (separate makes & models) and want to make sure that when I restart the RPi or accidentally unplug a USB sound card that the port number won't change and render my program useless.

I had a similar problem with USB serial devices.
I ended up solving it with udev by creating soft-links to the devices based on USB ID, see:
https://code.launchpad.net/~thomas-spri ... unk/remote
http://bazaar.launchpad.net/~thomas-spr ... ocal.rules

By using /dev/sierra (which was a sym-link to /dev/ttyUSBwhatever) I could reliably control the USB 3G dongle.