Raspberry PI automatic A2DP receiver script. Handles several devices which may connect and disconnect live. Source: http://www.blackv.tk/projects/retropi/raspberry-pi-a2dp-audio-sink/

gistfile1.sh

#!/bin/sh

#change if you don't use default audio out
AUDIOSINK="alsa_output.platform-bcm2835_AUD0.0.analog-stereo"

echo "Executing bluetooth script...|$ACTION|" >> /var/log/bluetooth_dev

ACTION=$(expr "$ACTION" : "\([a-zA-Z]\+\).*")
if [ "$ACTION" = "add" ]
then
   for dev in $(find /sys/devices/virtual/input/ -name input*)
   do
      if [ -f "$dev/name" ]
      then
         mac=$(cat "$dev/name" | sed 's/:/_/g')
         bluez_dev=bluez_source.$mac

         sleep 1

         CONFIRM=`sudo -u pi pactl list short | grep $bluez_dev`
         EXISTS=`sudo -u pi pactl list short | grep "module-loopback\ssource=$bluez_dev"` # exists if this is not zero
         if [ ! -z "$CONFIRM" -a -z "$EXISTS" ]
         then
            echo "Setting bluez_source to:  $bluez_dev" >> /var/log/bluetooth_dev
            echo pactl load-module module-loopback source=$bluez_dev sink=$AUDIOSINK rate=44100 adjust_time=0 >> /var/log/bluetooth_dev
            sudo -u pi pactl load-module module-loopback source=$bluez_dev sink=$AUDIOSINK rate=44100 adjust_time=0 >> /var/log/bluetooth_dev
         fi
      fi
   done
fi
if [ "$ACTION" = "remove" ]
then
  # better run the following several times, it won't hurt, it will just try to
  # remove loopback-modules for bluetooth devices that no longer exist
  for i in 1 2 3 4 5 
  do
    echo trying to remove stale bluetooth devices "($i/5)"... >>/var/log/bluetooth_dev
    for removed_entry in $(sudo -u pi pactl list short | grep module-loopback.source= | sed 's/.*source=bluez_source.\(.._.._.._.._.._..\).*/\1/' | sed 's/_/:/g' | grep -vF "`sudo -u pi pactl list short | grep module-bluetooth-device | grep address | sed 's/.*address=.\(..:..:..:..:..:..\)..*/\1/'`")
    do
      echo removed entry: $removed_entry >> /var/log/bluetooth_dev
      module_n=$(sudo -u pi pactl list modules short | grep module-loopback | grep `echo $removed_entry | sed 's/:/_/g'` | awk '{ print $1; }')
      echo sudo -u pi pactl unload-module $module_n >> /var/log/bluetooth_dev
      sudo -u pi pactl unload-module $module_n
    done
  sleep 1s
  done
  echo ending remove process >>/var/log/bluetooth_dev
fi