send data with timestamp to influx

[air-quality] / zph02.pl

diff --git a/zph02.pl b/zph02.pl
index 50aadcb..44d35ef 100755 (executable)
--- a/zph02.pl
+++ b/zph02.pl
@@ -3,11 +3,11 @@ 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 $port = shift @ARGV || '/dev/serial/by-path/platform-3f980000.usb-usb-0:1.5:1.0';
+my $influx_url = shift @ARGV || 'http://10.13.37.92:8086/write?consistency=any&db=rot13';
 
 my $s = new Device::SerialPort( $port ) || die $!;
 $s->baudrate(9600);
@@ -21,15 +21,33 @@ $s->read_const_time(10);
 
 while (1) {
 
+       alarm 3;
+       # Usb serial which I'm using is buggy and blocks from time to time.
+       # This will ensure that we have passed here every 3 seconds
+       # or we will be killed and systemd will restart us
+
        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 ), $/;
+               #warn "# $len ",dump($string), dump( @v ), $/;
+
+               my $sum = 0;
+               # -2 is specified in datasheet, next byte is 0 so it's same as -1
+               foreach my $i ( 0 .. $#v - 2 ) {
+                       $sum += $v[$i];
+                       $sum = $sum & 0xff;
+               }
+               $sum = ~$sum & 0xff;
+
+               my $checksum = $v[8];
                my $pcnt = $v[3] + ( $v[4] / 100 );
-               if ( $v[0] == 0xff ) {
-                       my $influx = "zph02,dc=trnjanska pm25_pcnt=$pcnt";
+               if ( $v[0] == 0xff && $sum == $checksum ) {
+                       my $influx = "zph02,dc=trnjanska pm25_pcnt=$pcnt $t";
                        print "$influx\n";
-                       system "curl --silent -XPOST '$influx_url' --data-binary '$influx'"
+                       system "curl --silent -XPOST '$influx_url' --data-binary '$influx'";
+                       system "mosquitto_pub -h rpi2 -t 'air/zph02/pm25' -m $pcnt";
                }
        }