#!/usr/bin/perl -w

use strict;
use warnings;
use Device::SerialPort;

my $port = Device::SerialPort->new("/dev/ttyUSB0");
$port->databits(8);
$port->baudrate(115200);
$port->parity("none");
$port->stopbits(1);
$port->handshake("on");
$port->write_settings;

$port->write(chr(254));
$port->write(chr(27));

my $char = $port->lookfor();
if ($char) {
 print "$char";
}