I use rfcomm for connecting to my arduino via bluetooth module (rs232). I found the manual way but I would like an automated way as in previous versions of opensuse (before 13.3). How do I do that if there is no /dev/bluetooth/rfcomm.conf ? 
There was no version 13.3 - I guess you mean 13.2?
How do I do that if there is no /dev/bluetooth/rfcomm.conf ?
I haven’t played with BT for years, but you could script it and have it start at boot eg via a systemd service perhaps.
Just in case this is helpful to you (I’m sure you can adapt this R.Pi approach to your Arduino?)
http://blog.dmaggot.org/2014/07/shell-access-to-your-raspberry-pi-over-bluetooth/
Thanks, already did it. I was looking for more elegant way to do it.
Thank you again.