sub setup_serial_interface {
    #my $seconds_per_transmission = 0.567;
    my $seconds_per_transmission = 1;

    $SIG{ALRM} = sub {
        push @serial_data, rand;
        alarm $seconds_per_transmission;
    };

    # First packet of data should occur in a couple seconds
    #alarm 2.5;
    alarm 3;
}