use Win32::SerialPort 0.05;
use strict;

my $current_position=2350;
my $mask_total=135;
my $vlc="vlc.exe";
my $serial_port="COM1";

my $detected_ratio;
my $serialobject;
my $interval=$current_position/$mask_total;
my $adjustment;
print "Step interval = $interval\n";
unless ($serialobject = Win32::SerialPort->new ($serial_port)) {
    printf "could not open serial port\n";
    exit 1;
}
$serialobject->baudrate(2400)             || die "bad baudrate";
$serialobject->parity('none')             || die "bad parity";
$serialobject->databits(8)                || die "bad databits";
$serialobject->stopbits(1)                || die "bad stopbits";
$serialobject->write_settings             || undef $serialobject;
my $pid = open(VLC, "$vlc  2>&1 |"); 
print "Resetting...\n";

$serialobject->write("r".chr(0));
get_serial_response();

while (<VLC>) 
{ 
	if ($_ =~/ratio/)
	{
		my @tmpratio=split (/ /);
		$detected_ratio=$tmpratio[5];
		chomp $detected_ratio;
		print "Detected Ratio = $detected_ratio\n";
		print "Current Postition: $current_position\n";
		my $move;
		if ($detected_ratio > $current_position)
		{
			$adjustment= $detected_ratio-$current_position;		
			print "Adjustment: Open $adjustment\n";	
			$move=int($adjustment/$interval);	
			print "Open: ".$move." increments\n";
			$serialobject->write("o".chr($move));
			$current_position=$detected_ratio;
			get_serial_response();
		}
		elsif ($detected_ratio < $current_position)
		{
			$adjustment= $current_position-$detected_ratio;		
			print "Adjustment: Close $adjustment\n";	
			$move=int($adjustment/$interval);
			print "Closing: ".$move." increments\n";
			$serialobject->write("c".chr($move));
			$current_position=$detected_ratio;
			get_serial_response();
		}
		else
		{
			print "No Ratio Change\n";
		};
	};
};


sub get_serial_response
{
	my $current_time=time();
	my $serin;
	
	while (!$serin )
	{
		if ((time()-$current_time) < 10)
		{
			$serin=$serialobject->input();
		}
		else
		{
			print "Position error - no response\n";
			last;
		};
	};
	print "Positioning complete \n\n";
};