my $PORT = "/dev/ttyS0";
system ("baud=19200 stop=1 data=8 parity=n");
open DEV,"+<$PORT" or die "Failed to open port\n";
my $ofh = select(DEV); $| = 0; $/='>'; select($ofh);

##</code><code>##

my @data = (3, 1, 255, 253);				
my $packeddata = pack("C*", @data);

print DEV $packeddata;

my $output = <DEV>;
#print "Output: $output ";