Difference between revisions of "Code/tp-theft"

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m (added forgotten hash for comment)
 
(One intermediate revision by one other user not shown)
Line 65: Line 65:
 
my $use_light = 0;  # 0=off, 1=on
 
my $use_light = 0;  # 0=off, 1=on
  
 +
# Use AC state to monitor
 +
my $use_ac_state = 1; # 0=off, 1=on
 
##############################
 
##############################
 
# Activation control
 
# Activation control
Line 125: Line 127:
 
my $volume_file = '/proc/acpi/ibm/volume'; # load ibm_acpi with experimental=1
 
my $volume_file = '/proc/acpi/ibm/volume'; # load ibm_acpi with experimental=1
 
my $bluetooth_file = '/proc/acpi/ibm/bluetooth'; # load ibm_acpi with experimental=1
 
my $bluetooth_file = '/proc/acpi/ibm/bluetooth'; # load ibm_acpi with experimental=1
 +
my $ac_state_file = '/proc/acpi/ac_adapter/AC/state'; # ac state
  
 
my $alsactl = '/usr/sbin/alsactl';
 
my $alsactl = '/usr/sbin/alsactl';
Line 320: Line 323:
 
}
 
}
  
 +
##############################
 +
# AC state checking
 +
 +
my $ac_state;
 +
sub read_ac_state {
 +
        open F, $ac_state_file;
 +
        if ((<F>) =~ /^state:\s*(on|off)-line$/)
 +
                {
 +
                    $ac_state=$1;
 +
                }
 +
                close F;
 +
            return($1);
 +
                  }
 +
        read_ac_state;
 +
  ### used for testing      print "AC: $ac_state\n";
  
 
##############################
 
##############################
Line 497: Line 515:
 
my $arm_forced = 0;
 
my $arm_forced = 0;
 
my (@XHIST, @YHIST); # sensor history
 
my (@XHIST, @YHIST); # sensor history
 +
 +
my $initpower=read_ac_state();  #check power state when script runs
  
 
sub set_state {
 
sub set_state {
Line 554: Line 574:
 
         $last_tilt = $now if $tilted;
 
         $last_tilt = $now if $tilted;
 
     }
 
     }
 +
 +
# ac state check and set when system started on battery and later plugged power cord
 +
    my $power = read_ac_state();
 +
        if ($initpower eq 'off' && $power eq 'on') {
 +
        $initpower='on';
 +
        }
  
 
     # Decide: state machine transitions
 
     # Decide: state machine transitions
Line 607: Line 633:
 
     }
 
     }
  
     # Alarm:
+
     # Alarm:  
     if (($state==4 || $state==6 || $state==7) && $tilted) {
+
    # included initpower state
 +
     if (($state==4 || $state==6 || $state==7) && ($tilted || ($power eq 'off') && $initpower eq 'on')) {
 
         sound_alarm("ALARM", $alarm_volume, $acpi_volume, $alarm_cmd);
 
         sound_alarm("ALARM", $alarm_volume, $acpi_volume, $alarm_cmd);
 
     }
 
     }

Latest revision as of 05:15, 22 January 2014

#!/usr/bin/perl
#
# tp-theft v0.5.1
# (http://thinkwiki.org/wiki/Script_for_theft_alarm_using_HDAPS)

# Provided under the GNU General Public License version 2 or later or
# the GNU Free Documentation License version 1.2 or later, at your option.
# See http://www.gnu.org/copyleft/gpl.html for the Warranty Disclaimer.

# This script uses the HDAPS accelerometer found on recent ThinkPad models
# to emit an audio alarm when the laptop is tilted. In sufficiently
# populated environments, it can be used as a laptop theft deterrent.
# Uses a state machine and some heuristics to reduce false alarms.
#
# By default the alarm will be activated only when the KDE screen saver is
# locked. If you you open the laptop lid (or press the lid button) shortly
# before or after the beginning of movement, the alarm will be suspended
# (except for a brief warning) and you will get a few seconds of grace to 
# unlock the screen saver. You can disable this functionality by passing 
# the "--arm" parameter, or by setting  $use_kde=0 and $use_lid=0.
#
# There is also an option to track a BlueTooth device (e.g., a mobile phone).
# In this case, the alarm is activated (and optionally, the KDE desktop is 
# locked) whenever the device is turned off or too distant for a given period,
# and deactivated when the BlueTooth device is nearby. You need to provide the
# device's BD address. If both KDE screen saver and BlueTooth checking are
# enabled, then the alarm will be activated when *either* the screensaver
# is enabled or the BlueTooth device is amiss.
#
# To control the sound and blinkenlights, and adjust the alarm activation 
# parameters, see the variables below.

use strict;
use warnings;
use FileHandle;
use IO::Pipe;
use Time::HiRes qw(sleep time);
use POSIX qw(:errno_h :signal_h);

##############################
# Siren volume and content

# Alarm audio volume (0..100)
my $alarm_volume = 70;
# Alarm command (default: synthesize a siren for 1.0 seconds):
my $alarm_cmd = "sox -t nul /dev/null -t wav -s -w -c2 -r48000 -t raw - synth 1.0 sine 2000-4000 sine 4000-2000 | aplay -q -fS16_LE -c2 -r48000";
# my $alarm_cmd = "aplay keep_your_hands_off_me.wav";

# Warning audio volume (0..100)
my $warn_volume = 45;
# Alarm command (default: synthesize a biref siren):
my $warn_cmd = "sox -t nul /dev/null -t wav -s -w -c2 -r48000 -t raw - synth 0.10 sine 2000-4000 sine 4000-2000 | aplay -q -fS16_LE -c2 -r48000";
# my $warn_cmd = "aplay warning.wav";

# Set ibm_acpi volume (0..15), if ibm_acpi is loaded with "experimental=1".
# Combining $acpi_volume=15 and $alarm_volume=100 makes the alarm 
# dangerously loud.
my $acpi_volume = 10;

# Blink system LEDs when alarm activated?
my $use_led = 'safe';  # 0=off, 'safe'=only LEDs whose state you can recover, 'all'=pretty blinkenlights!

# Blink ThinkLight when alarm activated?
my $use_light = 0;  # 0=off, 1=on

# Use AC state to monitor 
my $use_ac_state = 1; # 0=off, 1=on
##############################
# Activation control

# Tilt threshold (increase value to decrease sensitivity):
my $thresh = 0.20;
# Minimum movement duration between warning and alarm:
my $min_hold = 1.3;
# When armed, any movement triggers alarm. How long should it remain armed?
my $arm_persist = 6;

# After this many seconds of no movement, will allow a grace period again:
my $grace_relax = 15;

# Activate according to KDE screen saver? Otherwise, always active:
my $use_kde = 1;
# When screen saver locked, wait this long before activation:
my $kde_lock_delay =  8;

# Provide grace period if laptop lid is opened?
my $use_lid = 1;
# Opening a lid will grant this many seconds of grace (once):
my $lid_grace = 7;
# Lid must to be opened within this time to hold/pause alarm:
my $lid_grace_window = 8;
# Alarm will hold off this long when grace is available:
my $lid_hold = 3;

# Control arming according by presence of a BlueTooth token
my $use_bluetooth = 0;
# Lock KDE screen saver when BlueTootk is not present?
my $bluetooth_lock_kde = 1;
# BD address of BlueTooth token (use "hcitool scan" to find this)
my $bluetooth_token_addr = '00:00:00:00:00:00';
# Consider token amiss when its received signal leve is below this (see "hcitool rssi")
my $bluetooth_min_rssi = -10;
# Activate if BlueTooth token not seen this long:
my $bluetooth_activate_period = 12;
# Disactivate if BlueTooth token seen this recently:
my $bluetooth_deactivate_period = 5;
# If BlueTooth detection activated KDE lock, don't do it again for this long
my $bluetooth_lock_kde_interval = 30;
# If BlueTooth wasn't polled for this long, disregard recent history
my $bluetooth_reset_period = 10; 

##############################
# Other setup vars

my $interval = 0.1;  # sampling intervalm in seconds
my $depth = 10;      # number of recent samples to analyze
my $verbose = 2;     # 0=nothing, 1=alarms, 2=state transitions, 3=everything
my $kde_check_interval = 1.5; # KDE screen saver check is expensive
my $bluetooth_sleep = 1;       # Sleep interval in BlueTooth check loop

my $pos_file = '/sys/devices/platform/hdaps/position';
my $lid_file = '/proc/acpi/button/lid/LID/state';
my $led_file = '/proc/acpi/ibm/led';
my $light_file = '/proc/acpi/ibm/light';
my $bay_file = '/proc/acpi/ibm/bay';
my $volume_file = '/proc/acpi/ibm/volume'; # load ibm_acpi with experimental=1
my $bluetooth_file = '/proc/acpi/ibm/bluetooth'; # load ibm_acpi with experimental=1
my $ac_state_file = '/proc/acpi/ac_adapter/AC/state'; # ac state 

my $alsactl = '/usr/sbin/alsactl';
my $amixer = 'amixer';
my $kdesktop_lock = '/usr/bin/kdesktop_lock';
my $hcitool = '/usr/bin/hcitool';
my $l2ping = '/usr/bin/l2ping';

##############################
# Utility functions

sub say {
    my ($verb, $what) = @_;
    print(gmtime().": $what\n") if $verb<=$verbose;
}

sub slurp { # read whole file
    my ($filename) = @_;
    local $/;
    my $fh = new FileHandle($filename,"<") or return;
    return <$fh>;
}

sub burp { # write whole file
    my ($filename) = shift;
    my $fh = new FileHandle($filename,">") or die "Can't open $filename for writing: $!";
    print $fh @_ or die "Can't write to $filename: $!";
    close $fh or die "Can't close $filename after writing: $!";
}

sub stddev { # standard deviation of list
    my $sum=0;
    my $sumsq=0;
    my $n=$#_+1;
    for my $v (@_) {
        $sum += $v;
        $sumsq += $v*$v;
    }
    return sqrt($n*$sumsq - $sum*$sum)/($n*($n-1));
}

sub frac {
    my ($x) = @_;
    return $x-int($x);
}

sub max {
    return $_[0] > $_[1] ? $_[0] : $_[1];
}

my $alarm_file; # flags ongoing alarm (and also stores saved mixer settings)

sub sound_alarm {
    # Sound alarm. Forks bash code which sets given volumes, runs the given
    # command, and then restores the given volumes to their saved values.
    my ($name, $volume, $acpi_volume, $cmd) = @_;
    return if (defined($alarm_file) && -f $alarm_file);
    say(1,$name);
    $alarm_file = `mktemp /tmp/tp-theft-tmp.XXXXXXXX` or die "mktemp: $?";
    chomp($alarm_file);
    my ($acpi_vol_file, $acpi_vol_set, $acpi_vol_restore);
    if ($_=slurp($volume_file) and m/^level:\s+(\d+)\n/) {
        $acpi_vol_file = $volume_file; 
        $acpi_vol_set = "level $acpi_volume"; 
        $acpi_vol_restore = "level $1"; 
        if (m/^mute:\s+on$/m) {
          $acpi_vol_set = "up,".$acpi_vol_set; # unmute first
          $acpi_vol_restore .= ",mute";         # mute last
        }
    } else {
        $acpi_vol_file='/dev/null'; $acpi_vol_set=''; $acpi_vol_restore='';
    }
    system('/bin/bash', '-c', <<"EOF")==0 or die "Failed: $?";
( trap \"echo '$acpi_vol_restore' > $acpi_vol_file; sleep 0.1;
         $alsactl -f $alarm_file restore;
         rm -f $alarm_file
       \" EXIT HUP QUIT TERM
  $alsactl -f $alarm_file store &&                         # store ALSA
  echo '$acpi_vol_set' > $acpi_vol_file && sleep 0.1 &&    # set ACPI
  $amixer -q set Master $volume% unmute &&                 # set ALSA Master
  $amixer -q set PCM 100% unmute &&                        # set alsa PCM
  $cmd ) &                                                 # invoke command
EOF
}


##############################
# KDE screen saver lock check

if ($use_kde) { # Basic sanity check
    `/sbin/pidof kdesktop`; $?==0 or die "Can't use KDE, it's not running.\n";
}

sub kdesktop_lock_status {
    # See if kdesktop_lock is running and check its cmdline and automatic lock delay
    my $bin = $kdesktop_lock;
    my $pids = `/sbin/pidof $bin`;
    return 'off' unless $?==0;
    for my $pid (split(/\s+/,$pids)) {
        next unless $pid =~ m/^\d+$/;
        # Attached to display ":0" or "localhost:0"?
        my $environ = slurp("/proc/$pid/environ") or next;
        my $good=0; my $home;
        for (split(/\x00/,$environ)) { 
            $good=1 if m/^DISPLAY=(localhost)?:0$/; 
            $home=$1 if m/^HOME=(.+)$/;  # also remember its $HOME
        }
        next unless $good;
        # Check command line
        my $cmdline = slurp("/proc/$pid/cmdline") or next;
        $cmdline =~ m/^[^\x00]+\x00(?:([^\x00]+)\x00)?/ or die "Cannot parse $bin command line\n";
        if (!defined($1)) {
            # Read KDE screensaver lock time
            defined($home) or die "Cannot find HOME in environment of $bin process";
            my $rc_path = "$home/.kde/share/config/kdesktoprc";
            my $rc = new FileHandle($rc_path,"<") or die "Error opening $rc_path: $!";
            while (<$rc>) { m/^LockGrace=(\d+)$/ and return ('auto', $1/1000.0); };
            die "Cannot parse $rc_path";
        } elsif ($1 eq '--forcelock') {
            return "force";
        }
    }
    return 'off';
}

my $last_kls_update = 0; # time of last update
my $last_kls = 'init';   # last state seen
my $last_kls_start;      # when that state started
my @last_kls_opwhy = ();

sub check_kde_lock {
    # De/activate according to KDE screen saver:
    my $now=time();
    return @last_kls_opwhy if $now < $last_kls_update + $kde_check_interval;
    my ($kls, $auto_delay) = kdesktop_lock_status();
    $last_kls_update = time();
    if ($kls ne $last_kls) {
        $last_kls = $kls;
        $last_kls_start = $now;
    }
    if ($kls eq 'off') { # no screen saver
        @last_kls_opwhy = (0, 'KDE screen saver not locked');
    } elsif ($kls eq 'auto') { # screen saver with automatic lock
        if ($now >= $last_kls_start + $auto_delay + $kde_lock_delay) {
            @last_kls_opwhy = (1, 'KDE screen saver is auto-locked');
        }
    } elsif ($kls eq 'force') { # screen saver with forced lock
        if ($now >= $last_kls_start + $kde_lock_delay) {
            @last_kls_opwhy = (1, 'KDE screen saver is forced-locked');
        }
    }
    return @last_kls_opwhy;
}

# Lock KDE desktop
sub force_kde_lock {
    return if ($last_kls eq 'auto' or $last_kls eq 'force');
    say(1, "Locking KDE desktop");
    # system('dcop kdesktop KScreensaverIface lock') or die "Cannot lock KDE dekstop: $!"

    my %oldENV = %ENV;
    my $kde_pids = `/sbin/pidof -x /usr/bin/startkde`;
    for my $kde_pid (split(/\s+/,$kde_pids)) {
        my $kde_env = slurp("/proc/$kde_pid/environ") or next;
        %ENV = ();
        for (split(/\x00/,$kde_env)) {
            m/^(DISPLAY|HOME|XAUTHORITY|USER|DBUS_SESSION_BUS_ADDRESS)=(.+)$/
                and $ENV{$1} = $2;
        }
        next unless defined($ENV{DISPLAY}) and $ENV{DISPLAY} =~ m/^:/;
        system('dcop kdesktop KScreensaverIface lock') and die "Cannot lock KDE dekstop: $!"
    }
    my %ENV = %oldENV;
}

##############################
# Lid checking

if ($use_lid) { # sanity check
    slurp($lid_file) or die "Can't use lid via $lid_file: $!";
}

my $last_lid_status = 'open';
my $last_lid_open = 0;

sub check_lid {
    my $lid = slurp($lid_file) or return;
    if ($lid =~ m/state: *open$/) {
        $last_lid_open = time() if ($last_lid_status eq 'closed');
        $last_lid_status = 'open';
    } else {
        $last_lid_status = 'closed';
    }
    return $last_lid_status;
}

##############################
# AC state checking

my $ac_state;
sub read_ac_state {
        open F, $ac_state_file;
        if ((<F>) =~ /^state:\s*(on|off)-line$/)
                {
                    $ac_state=$1;
                }
                close F;
            return($1);
                  }
        read_ac_state;
  ### used for testing       print "AC: $ac_state\n";

##############################
# LED blinking

# Flash LEDs
sub led_activate {
    return if $use_led eq '0';
    my $ledf = new FileHandle($led_file,">");
    if (!defined($ledf)) {
        print "Cannot open $led_file, disabling LED indicator: $!\n";
        $use_led = '0';
        return;
    }
    $ledf->autoflush(1);
    my $base = time()*2.5;
    print $ledf '0 '.((frac($base)>0.7)?'on':'off')."\n"; # power
    if ($use_led eq 'all') { # battery -- we can't recover these
        print $ledf '1 '.((frac($base+0.50)>0.7)?'on':'off')."\n"; # battery, orange
        print $ledf '2 '.((frac($base+0.25)>0.7)?'on':'off')."\n"; # battery, yellow
    }
    print $ledf '4 '.((frac($base)>0.7)?'on':'off')."\n"; # bay
    print $ledf '7 '.((frac($base+0.725)>0.7)?'on':'off')."\n"; # standby
}

# Restore LEDs to normal state
sub led_restore {
    return if $use_led eq '0';
    my $ledf = new FileHandle($led_file,">") or die "Cannot open $led_file: $!\n";
    $ledf->autoflush(1);
    print $ledf "0 on\n"; # power=on
    if ($use_led eq 'all') { # battery -- we can't recover these
        print $ledf "1 on\n";
        print $ledf "2 on\n";
    }
    print $ledf "7 off\n"; # power=off
    if (my $baydata = slurp($bay_file)) {
        my $is_bay = ($baydata =~ m/^status:\s*occupied$/m)?'on':'off';
        print $ledf "4 $is_bay\n"; # reset to correct status
    } else {
        print $ledf "4 on\n"; # force bay on, we don't know correct status
    }
}


##############################
# ThinkLight blinking

sub light_activate {
    return if $use_light eq '0';
    my $lightf = new FileHandle($light_file,">");
    if (!defined($lightf)) {
        print "Cannot open $light_file, disabling ThinkLight indicator: $!\n";
        $use_light = '0';
        return;
    }
    my $base = time()/2;
    print $lightf (check_lid() eq 'open' && ((frac($base)<0.1)?'on':'off'))."\n";
}

sub light_restore {
    return if $use_light eq '0';
    my $lightf = new FileHandle($light_file,">") or die "Cannot open $light_file: $!\n";
    print $lightf "off\n"; # ThinkLight
}

##############################
# BlueTooth token detection


{
    my $temporary_bt = 0;
    my $bt_pid;
    my $bt_pipe;
    my $bluetooth_last_seen = 0; # last time we saw the BlueTooth token
    my $bluetooth_last_read = 0;   # last time we polled the BlueTooth child process
    my $bluetooth_ignore_missing_until = time() + $bluetooth_reset_period; 

    if ($use_bluetooth) {
        # If BlueTooth is disabled, temporarily enable it
        slurp($bluetooth_file) or die "Can't control bluetooth via $bluetooth_file: $!";
        my $bt_status = slurp($bluetooth_file);
        $temporary_bt = $bt_status =~ m/status:[\t]*disabled/;
        if ($temporary_bt) {
            say(1, 'BlueTooth was disabled, enabling');
            burp($bluetooth_file, "enable\n");
            sleep(1);
        }
    }

    sub bluetooth_reset {  # disregard recent (negative) history
        $bluetooth_ignore_missing_until = max($bluetooth_ignore_missing_until, time() + $bluetooth_reset_period);
    }

    sub check_bluetooth {
        if (!defined($bt_pid)) {
            # Create new child process, which will loop checking
            # for the token. Each time it sees the token, it writes
            # the current time to a pipe that's read by the main process.
            $bt_pipe = new IO::Pipe;
            $bt_pid = fork();
            die "Cannot fork BlueTooth check: $!" unless defined($bt_pid);
            if (!$bt_pid) {
                # Child
                $bt_pipe->writer();
                $bt_pipe->autoflush(1);
                open(STDOUT, ">/dev/null");
                open(STDERR, ">/dev/null");
                while(1) {
                    # Is the BlueTooth token reachable?
                    my $res = system($l2ping,'-c','1','-t',1,$bluetooth_token_addr);
                    die "Failed invoking l2ping: $!\n" if $res&0xFF;
                    if ($res==0) {
                       # Is the BlueTooth sufficiently close, as judged by signal strength?
                       $res = `$hcitool rssi $bluetooth_token_addr`;
                       if ($?==0 && $res =~ m/^RSSI return value: (-?[0-9]+)$/) {
                           my $rssi = $1;
                           printf $bt_pipe "%d\n", time() if ($rssi > $bluetooth_min_rssi);
                       }
                    }
                    sleep($bluetooth_sleep);
                }
             }
             $bt_pipe->reader();
             $bt_pipe->blocking(0);
        }

        while (1) { 
            my $res = <$bt_pipe>;
            last if ($!==POSIX::EAGAIN); # busy
            die "Error reading from BlueTooth check child process\n" unless defined($res);
            $bluetooth_last_seen = $res;
        }

        my $now = time();
        bluetooth_reset() if ($now > $bluetooth_last_read + $bluetooth_reset_period);
        $bluetooth_last_read = time();
        if ($now > max($bluetooth_last_seen + $bluetooth_activate_period, $bluetooth_ignore_missing_until)) {
            if ($bluetooth_lock_kde) {
                force_kde_lock();
                $bluetooth_ignore_missing_until = max($bluetooth_ignore_missing_until, time() + $bluetooth_lock_kde_interval);
            }
            return (1, "BlueTooth token not seen for $bluetooth_activate_period seconds, activating.");
        } elsif ($now < $bluetooth_last_seen + $bluetooth_deactivate_period) {
            return (0, "BlueTooth token seen during last $bluetooth_deactivate_period seconds, deactivating.");
        }
        return ();
    }

    sub bluetooth_restore {
        if ($temporary_bt) {
            say(1, 'Disabling BlueTooth');
            burp($bluetooth_file, "disable\n");
        }
        if ($bt_pid) {
            kill(SIGTERM, $bt_pid);
            waitpid($bt_pid, 0);
        }
    }
}

##############################
# Main code

my $state;       # See state machine in main loop
my %state_names=(0  =>'disabled    ',
                 0.5=>'activating  ',
                 1  =>'active+grace',
                 2  =>'active      ',
                 3  =>'hold+grace  ',
                 4  =>'armed+grace ',
                 5  =>'hold        ',
                 6  =>'armed       ',
                 7  =>'armed-force '  );
my $state_end = 0; 
my $last_tilt = 0;
my $arm_forced = 0;
my (@XHIST, @YHIST); # sensor history

my $initpower=read_ac_state();  #check power state when script runs

sub set_state {
    my ($st,  $why) = @_;
    say(2, "state=[".$state_names{$st}."]  ($why)");
    (@XHIST, @YHIST) = () if $st==0.5;
    led_restore() and light_restore() if defined($state) && $st==0;
    $state = $st;
}

sub get_pos {
    my $pos = slurp($pos_file);
    return undef if $!{EBUSY};
    die "Can't open HDAPS file $pos_file: $!\n" if (!defined($pos) || $!);
    $pos =~ m/^\((-?\d+),(-?\d+)\)$/ or die "Can't parse $pos_file content\n";
    return ($1,$2);
}


for (@ARGV) {
    m/^--arm/ && do { $arm_forced=1; $use_lid=0; $use_kde=0; last; };
    die "Unknown parameter\n";
}

set_state( ($use_kde || $use_bluetooth)  ? 0 : 0.5, "init");

eval {

$SIG{'HUP'}=$SIG{'INT'}=$SIG{'ABRT'}=$SIG{'QUIT'}=$SIG{'SEGV'}=$SIG{'TERM'} = sub { die "signal\n" };

while (1) {
    sleep(($state==0 && $use_kde) ? $kde_check_interval : $interval);

    check_lid() if $use_lid;
    # Check screensaver and BlueTooth. Activate if either says so,
    # otherwise deactivate if either says so.
    my ($op1, $why1); ($op1, $why1) = check_kde_lock() if $use_kde;
    my ($op2, $why2); ($op2, $why2) = check_bluetooth() if $use_bluetooth;
    my ($op, $why) = ( !defined($op1) || ( defined($op2) && $op2>$op1 ) ) ? ($op2,$why2) : ($op1,$why1);
    if (defined($op)) {
        if ($op==1 && $state==0) { set_state(0.5, $why); }
        if ($op==0 && $state>0) { set_state(0, $why); bluetooth_reset(); }
    }
    next unless $state>0;

    # Collect and analyze sensor data:
    my $now = time();
    my $tilted;
    my ($x,$y) = get_pos() or next; # Hopefully the error is transient
    push(@XHIST,$x); push(@YHIST,$y);
    if ($state>0.5) {
        shift(@XHIST); shift(@YHIST);
        my $xdev = stddev(@XHIST);
        my $ydev = stddev(@YHIST);
        say(3,"X: v=$xdev (".join(',',@XHIST).")  Y: v=$ydev (".join(",",@YHIST).")");
        $tilted = ($xdev>$thresh || $ydev>$thresh);
        $last_tilt = $now if $tilted;
    }

# ac state check and set when system started on battery and later plugged power cord
    my $power = read_ac_state();
        if ($initpower eq 'off' && $power eq 'on') {
        $initpower='on';
        }

    # Decide: state machine transitions
    if ($state==0.5) { # ACTIVATING  (collecting motion data will soon activate)
        if ($#XHIST >= $depth && $#YHIST >= $depth) {
            set_state($arm_forced?7:$use_lid?1:2, "finished data collection");
        }
    } elsif ($state==1) { # ACTIVE+GRACE  (quiet for a long time, awaiting movement)
        if ($tilted) {
            set_state(3, "motion detected, holding for $lid_hold seconds, open lid for grace");
            $state_end = $now + $lid_hold;
            sound_alarm("WARNING", $warn_volume, $acpi_volume, $warn_cmd);
        }
    } elsif ($state==2) { # ACTIVE  (short for a shorter time, awaiting movement)
        if ($tilted) {
            set_state(5, "motion detected, holding for $min_hold seconds");
            $state_end = $now + $min_hold;
            sound_alarm("WARNING", $warn_volume, $acpi_volume, $warn_cmd);
        } else {
            if ($use_lid && ($now > $last_tilt + $grace_relax )) { 
                set_state(1, "$grace_relax seconds since last motion, so allowing grace again");
            }
        }
    } elsif ($state==3) { # HOLD+GRACE  (recent movemvent, but still holding off alarm; after long quiet)
        if ($now < $last_lid_open + $lid_grace) {
            set_state(5, "lid opened, holding for $lid_grace seconds grace period");
            $state_end = $now + $lid_grace;
        } elsif ($now >= $state_end) {
            my $delta = $lid_grace_window - $lid_hold;
            $state_end = $now + $delta;
            set_state(4, "hold ended, arming but allowing grace for $delta more seconds");
        }
    } elsif ($state==4) { # ARMED+GRACE  (armed, but recently quiet so allow grace if lid opened)
        if ($now < $last_lid_open + $lid_grace) {
            set_state(5, "lid opened, holding for $lid_grace seconds grace period");
            $state_end = $now + $lid_grace;
        } elsif ($now >= $state_end) {
            set_state(6, "grace window ended");
        }
    } elsif ($state==5) { # HOLD  (recent movement, but still holding off alarm; there was recent action)
        if ($now >= $state_end) {
            set_state(6, "hold ended, arming");
        }
    } elsif ($state==6) { # ARMED  (sound alarm on any movement)
        if ($now > $last_tilt + $arm_persist) {
            set_state(2, "no motion for $arm_persist seconds, unarming");
        }
    }

    # LEDs:
    if ($state>0) {
        led_activate(); light_activate();
    }

    # Alarm: 
     # included initpower state
    if (($state==4 || $state==6 || $state==7) && ($tilted || ($power eq 'off') && $initpower eq 'on')) {
        sound_alarm("ALARM", $alarm_volume, $acpi_volume, $alarm_cmd);
    }
}

};

print "Shutting down.\n" if $verbose>1;
led_restore() and light_restore() if ($state>0);
bluetooth_restore();
die "$@" if $@;