Matt: +choice

2010-11-14T08:21:25Z

+choice

Matt: release

2010-11-13T21:28:21Z

release

New page

<pre>
#!/usr/bin/perl
# tp-theft-lcars v0.1 (http://thinkwiki.org/wiki/Script_for_theft_alarm_using_HDAPS)
# 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.
#
# This file is placed in the public domain and may be freely distributed.
#
# Here comes a modified version which requires an internet connection and gnash.
# It shows a LCARS red alert flash animation from Star Trek Voyager instead of a beep.

use strict;
use warnings;

##############################
# Audio volume (0..100)
my $volume = 70;

my $play_cmd = "gtk-gnash --fullscreen http://www.lcars.org.uk/lcars_files/LCARS_prey_emergency_scan_analysis.swf";

##############################
# Other tweakables

my $thresh = 0.20; # tilt threshold (increase value to decrease sensitivity)
my $interval = 0.1; # sampling interval in seconds
my $depth = 10; # number of recent samples to analyze
my $pos_file='/sys/devices/platform/hdaps/position';
my $verbose = 1;

##############################
# Code

sub get_pos {
open(POS,"<",$pos_file) or die "Can't open HDAPS file $pos_file: $!\n";
$_=<POS>;
m/^$(-?\d+),(-?\d+)$$/ or die "Can't parse $pos_file content\n";
return ($1,$2);
}

sub stddev {
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));
}

my (@XHIST, @YHIST);
my ($x,$y) = get_pos;
for (1..$depth) {
push(@XHIST,$x);
push(@YHIST,$y);
}
my $alarm_file; # flags ongoing alarm (and stores saved mixer settings)

while (1) {
my ($x,$y) = get_pos;
shift(@XHIST); push(@XHIST,$x);
shift(@YHIST); push(@YHIST,$y);
my $xdev = stddev(@XHIST);
my $ydev = stddev(@YHIST);

# Print variance and history
print "X: v=$xdev (".join(',',@XHIST).") Y: v=$ydev (".join(",",@YHIST).")\n" if $verbose>1;

my $tilted = $xdev>$thresh || $ydev>$thresh;

if ($tilted && !(defined($alarm_file) && -f $alarm_file)) {
print "ALARM\n" if $verbose>0;
$alarm_file = `mktemp /tmp/hdaps-tilt.XXXXXXXX` or die "mktemp: $?";
chomp($alarm_file);
system('/bin/bash', '-c', <<"EOF")==0 or die "Failed: $?";
($play_cmd) &
EOF
}

select(undef, undef, undef, $interval); # sleep
}
</pre>

@@ Line 1: / Line 1: @@
 <pre>
 #!/usr/bin/perl
-# tp-theft-lcars v0.1 (http://thinkwiki.org/wiki/Script_for_theft_alarm_using_HDAPS)
+# tp-theft-lcars v0.2 (http://thinkwiki.org/wiki/Script_for_theft_alarm_using_HDAPS)
 # This script uses the HDAPS accelerometer found on recent ThinkPad models
 # to emit an audio alarm when the laptop is tilted. In sufficiently
@@ Line 9: / Line 9: @@
+#
 # Here comes a modified version which requires an internet connection and gnash.
-# It shows a LCARS red alert flash animation from Star Trek Voyager instead of a beep.
+# It shows a LCARS red alert flash animation from Star Trek instead of a beep.
 use strict;
@@ Line 18: / Line 19: @@
 my $volume = 70;
-my $play_cmd = "gtk-gnash --fullscreen http://www.lcars.org.uk/lcars_files/LCARS_prey_emergency_scan_analysis.swf";
+# Voyager alert system status
 ##############################

Code/tp-theft-lcars - Revision history

Matt: +choice

Matt: release