Using multiple USB Bluetooth dongles on one linux host
When you buy cheap USB Bluetooth dongles, that they have the same device address (MAC). The tool
bdaddr can be used to change these addresses.
bdaddr - Utility for changing the Bluetooth device address Usage: bdaddr [-i <dev>] [-r] [-t] [new bdaddr]
To change the dongles address, connect only the one you want to modify and run:
$ bdaddr F4:4E:FD:B8:A4:14
Unplug and replug the dongle,
bluetoothd should now be able to configure
both USB Bluetooth dongles.