I'm using BlueZ and a USB Bluetooth adapter to provide ethernet to a Pi. Using this method here: Look Ma, no Wires! Raspberry Pi Bluetooth tethering
I'm building a low power project using a Model A which has no ethernet and only one USB port. The immediate problem I found was that I can't connect a USB keyboard and the Bluetooth adapter at the same time to set it up. So what I did was set it all up on a Model B (ssh via the Ethernet port). I set the bluetooth ethernet connection to start on boot. All systems go. I then transferred the SD card and the Bluetooth device (ie. the same MAC) to the Model A, crossed my fingers and... of course it didn't work.
It's not the ethernet bridge which is the problem, it just can't seem to see the USB devices at all.
sudo bluez-test-device list to the start script. This lists the paired devices. If no devices are paired it simply returns nothing. But on the Model A it fails with:
dbus.exceptions.DBusException: org.bluez.Error.NoSuchAdapter: No such adapter
I am thinking that installing BlueZ sets up a configuration specific to the USB chipset on the device. I can boot the same SD card in different Model Bs indicating the USB doesn't have any kind of serial or MAC like identifier. So there must be some other kind of difference between the USB port between Model A and B.
I'm fairly sure the USB port itself is OK because it works fine with a USB keyboard.
I have ordered a serial link cable so that I can I set up BlueZ directly on the Model A, but until that arrives I thought I would see if anyone had any ideas. I also tried using a USB hub, so I can also connect a keyboard but the hub I have doesn't want to work.