use warnings; # Handy
use strict;   # Even more handy
use IO::Socket::INET;

my $socket = IO::Socket::INET->new (
        LocalPort       => $config{'listenport'},
        Proto           => 'udp',
        Reuse           => 1,
) or die "Can't create listening socket: $@\n";

while (1)
{
        my $indata;
        # Read some data from the serial port
        # Read some data from a few files
        # ~300 lines of calculations go here, putting it all into $outdata when done
        shipout($outdata);
        # flush buffers, and other stuff
}

sub shipout
{
        my $datatoship = shift;
        # these lines should be replaced by something that 
        # that sends the contents of $datatoship to
        # everyone (or anyone) that is connected to $socket
        # if none is connected, just move on.
}

__END__