I need to identify a my bluetooth pen in the /dev directory, because I want to create a udev rule for it. Unfortunately I can't find it. Can anyone help me?
Serial bluetooth devices which you typically connect via rfcomm are named with the same suffix. E.g.
If you connect your device in a different way, you should consider to use the belonging tool (which is in the most cases bluez/ bluetoothctl or hcitool).
For an udev-bluetooth example where hcitool is used, have a look at Making udev rule for bluetooth keyboard