bt-sleep-monitor.sh

#!/bin/bash

## VARIABLES

# This value defines the default wakeup time (in seconds) when 'dispaly on' is triggered
btactive=120
# Default names for lock/log files
lockfile=/dev/shm/bt-sleep-monitor.lock
logfile=/dev/shm/bt-sleep-monitor.log


## PRESETS

# Create lock/log file
echo "0" > $lockfile
echo "$(date) log started" > $logfile
echo "1" > /proc/bluetooth/sleep/lpm
# Make logfile readable for anyone
chmod 777 $logfile


## FUNCTIONS

# Wakup Bluetooth (disable 'sleep mode' and wait for connection) / Go to 'sleep mode' again
wakeup() {
 # We check if the script is in 'locked' state
  if [ "$(cat $lockfile)" == "0" ] ; then
     # We wake up bluetooth for certain time and set a 'lock' until we go in 'sleep mode' again.
     echo "$(date) Bluetooth wakeup for 2 minutes" >> $logfile
     echo "0" > /proc/bluetooth/sleep/lpm
     echo "1" > $lockfile
     sleep $btactive
     # We check if a device is connetced. Otherwise we go to sleep and release the 'lock'.
     if  [ "$(hcitool con | grep \>)" == "" ] ; then
         echo "1" > /proc/bluetooth/sleep/lpm
         echo "0" > $lockfile
         echo "$(date) Sleep after active and release lock" >> $logfile
         # Call listener again
         killall dbus-monitor
         echo $(defaultlistener)
     else
         # We have a connection. If device disconnects, we go to sleep and release the 'lock'.
         echo "$(date) Device connected" >> $logfile
         dbus-monitor --system "interface='org.bluez.Control',member='PropertyChanged'" |
         while read -r line; do
             if [ "$(echo $line | awk 'END {print $NF}')" == "false" ]; then
                 echo "1" > /proc/bluetooth/sleep/lpm
                 echo "0" > $lockfile
                 echo "$(date) Device disconnected" >> $logfile
                 # Call listener again
                 killall dbus-monitor
                 echo $(defaultlistener)
             fi
         done
     fi
 fi
 }

# Main listener (always started again after bluetooth is goes into 'sleep mode').
defaultlistener() {
 # We listen for 'Disply on' DBus events.
 dbus-monitor --system "interface='com.nokia.mce.signal',member='display_status_ind'" |
 while read -r line; do
     if [ "$(echo $line | awk -F\" '{print $2}')" == "on" ]; then
         # Call wakeup function
         killall dbus-monitor
         echo $(wakeup)
     fi
 done
 }


## MAIN (start defaultlistener)
defaultlistener