How can I pair a Bluetooth dongle on arduino Yun (openwrt-yun)?
It takes me some time to make it work : 

1) update drivers

opkg update 

opkg install kmod-bluetooth bluez-libs bluez-utils


2) add configuration files in directory /etc/bluetooth

root@Arduino:~# cat /etc/bluetooth/hcid.conf

options {
  autoinit yes;
  security auto;
  pairing multi;
  passkey "0000";
   }
device {
  name "OpenWrt";
  class 0x000100;
  lm accept,master;
  lp rswitch,hold,sniff,park;
  }

root@Arduino:~# cat /etc/bluetooth/rfcomm.conf 

rfcomm0{
 bind yes;
 device 00:1B:C1:02:B0:F5;
 channel 1;
 comment "Holux M-1000";
 }


3) Reboot the card

4) test if all is OK

hciconfig


5) put the interface up

hciconfig hci0 up


6) Search for devices

hcitool scan


7) Look for Serial Port capability on the devices

sdptool search SP


8) bind the serial dev

rfcomm -i hci0 connect /dev/rfcomm0 00:1B:C1:02:B0:F5


9) see the information comming from the device (bluetooth GPS in my case)

cat /dev/rfcomm0