co2.pl

#!/usr/bin/perl

use strict;
use warnings;

open my $co2, "+>", "/dev/io8log" or die "$!";

my $message = pack "C*", 0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80;

my $ret = ioctl $co2, 0xC0094806, $message;

while (1) {
        my $bytes = read $co2, my $buf, 8;
        die "$bytes is not enough" unless $bytes == 8;

        my @values = unpack "C*", $buf;

        print join(" ", map { sprintf "%02x", $_ } @values), "\n";
}