Ok. Maybe the following will help.

package Device::SerialPort::Arduino;

use strict;
use warnings;

use Time::HiRes;
use Carp;
use Device::SerialPort;

use vars qw($VERSION);

our $VERSION = '0.07';

sub new {
    my $class = shift;
    
    my $self = bless {}, $class;

    my %init = @_;

    # Sets many parameters for Device::SerialPort usage

    $self->{'port'}     = $init{'port'};
    $self->{'baudrate'} = $init{'baudrate'};

    $self->{'databits'} = $init{'databits'};
    $self->{'parity'}   = $init{'parity'};
    $self->{'stopbits'} = $init{'stopbits'};

    $self->initialize();

    return $self;
}

sub initialize {

    my $self = shift;

    $self->{'DSP'} = Device::SerialPort->new( $self->{'port'} )
      or croak "Can't open " . $self->{'port'} . " - $!\n";

    # Checks if the baudrate was defined otherwise sets a default
    # value which is 9600

    $self->{'baudrate'} = 9600
      unless ( defined( $self->{'baudrate'} ) );

    $self->{'DSP'}->baudrate( $self->{'baudrate'} );

    # Checks for some default parameters which shouldn't be changed

    $self->{'databits'} = 8
      unless ( defined( $self->{'databits'} ) );

    $self->{'parity'} = 'none'
      unless ( defined( $self->{'parity'} ) );

    $self->{'stopbits'} = 1
      unless ( defined( $self->{'stopbits'} ) );

    # Sets the remaining parameters

    $self->{'DSP'}->databits( $self->{'databits'} );
    $self->{'DSP'}->parity( $self->{'parity'} );
    $self->{'DSP'}->stopbits( $self->{'stopbits'} );
}

sub communicate {

    my $self  = shift;
    my $chars = shift;
    
    # Returns 0 if $chars is an empty string

    return 0 unless $chars;

    $self->{'DSP'}->write($chars);

    return $chars;
}

sub receive {

    my $self  = shift;
    my $delay = shift;

    while (1) {

        # Check if any data is coming in. If true
        # returns the character just catched.

        my $char = $self->{'DSP'}->lookfor();

        return $char
            if $char;
        
        # The following lines, will be used for
        # slower reading, but lower CPU usage, and to
        # avoid buffer overflow due to sleep function. (arduino.cc)

        if ( defined $delay ) {
            $self->{'DSP'}->lookclear;

            sleep($delay);
        }
    }
}
[download]

James

I am working on a windows PC, not *nix. Device::SerialPort::Arduino cannot be installed on windows unless you install something like cygwin, which I do not intend to use.