use Win32::SerialPort qw( :STAT 0.19 );
my $PortObj = new Win32::SerialPort ("COM1") || die "Can't open COM1: $^E\n";
$PortObj->baudrate(9600);
$PortObj->parity("none");
$PortObj->databits(8);
$PortObj->stopbits(1);

$PortObj->write ("feed me");

$PortObj->close || die;
undef $PortObj;