MH-Z19B Co2 sensor

diff --git a/mh-z19b.pl b/mh-z19b.pl
new file mode 100755 (executable)
index 0000000..b71b365
--- /dev/null
+++ b/mh-z19b.pl
@@ -0,0 +1,55 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+# sudo apt install libdevice-serialport-perl libdata-dump-perl
+use Device::SerialPort;
+use Time::HiRes;
+use Data::Dump qw(dump);
+
+my $port = shift @ARGV || '/dev/ttyUSB0';
+my $influx_url = shift @ARGV || 'http://10.13.37.229:8186/write?db=telegraf';
+$influx_url = 'http://10.13.37.92:8086/write?db=rot13';
+
+my $s = new Device::SerialPort( $port ) || die $!;
+$s->baudrate(9600);
+$s->databits(8);
+$s->parity('none');
+$s->stopbits(1);
+$s->handshake('none');
+$s->read_char_time(0);
+$s->read_const_time(10);
+$s->debug(1);
+
+$s->write("\xFF\x01\x86\x00\x00\x00\x00\x00\x79");
+
+while (1) {
+
+       my ($len, $string) = $s->read(9);
+       my $t = int( Time::HiRes::time() * 1_000_000_000 );
+       die $! if ! defined($len);
+       if ( $len > 0 ) {
+               my @v = unpack('C*', $string);
+               #warn "# $len ",dump($string), dump( @v ), $/;
+
+               my $sum = 0;
+               foreach my $i ( 1 .. $#v - 1 ) {
+                       $sum += $v[$i];
+                       $sum = $sum & 0xff;
+               }
+               $sum = 0xff - $sum + 1;
+
+               my $checksum = $v[8] || die "no checksum";
+               my $co2 = $v[2] * 255 + $v[3];
+               if ( $v[0] == 0xff && $sum == $checksum ) {
+                       my $influx = "mh-z19b,dc=trnjanska co2=$co2 $t";
+                       print "$influx\n";
+                       system "curl --silent -XPOST '$influx_url' --data-binary '$influx'"
+               }
+               sleep 1;
+               $s->write("\xFF\x01\x86\x00\x00\x00\x00\x00\x79");
+       }
+
+};
+
+
+$s->close;