An It-slave in the digital saltmine

It-Slav.net is proud to announce as one of the temperature providers to temperatur.nu

It-slav.net provides temperature measurement for STHLM/Huddinge area in Sweden to the very popular site temperatur.nu

The measurment is done by a 1-wire temperature probe DS18S20.

The script that collects the temperature and stores it in a file that is presented as a webpage, the webpage is polled regularly by temperatur.nu

#!/usr/bin/perl
 #
 # rrd_tempsensor.pl

#use lib qw(/usr/local/rrdtool-1.2.15/lib/perl);
 use RRDs;
 use OW;

# define location of rrdtool databases
 my $rrd = '/root/owfs/script/rrd_db';
 # define location of images
 my $img = '/home/peter/public_html/temps';

# process data for each interface (add/delete as required)
 &ProcessSensor(0, "Temperatur_Huddinge", "op5.mynet",3001,"10.DEF05F010800");

sub ProcessSensor
 {
 # process sensor
 # inputs: $_[0]: sensor number (ie, 0/1/2/etc)
 #         $_[1]: sensor description
 print "number:$_[0] desc:$_[1], server:$_[2] port:$_[3], id: $_[4]\n";
 my $owserver = "$_[2]:$_[3]";

unless(OW::init($owserver)) {
 $status = $ERRORS{CRIT};
 $message = "OWServer not running at $owserver\n";
 exit $status;
 }

# get temperature from sensor
 my $handle = OW::get("$_[4]/temperature");
 #    print "handle=$handle\n";
 $handle =~ s/^\s*(.*?)\s*$/$1/;
 ## Check if input is an integer or decimal
 unless (($handle =~ /^-?(?:\d+(?:\.\d*)?|\.\d+)$/) || ($handle =~ /^[+-]?\d+$/))
 {
 print "Not an integer or a decimal\n";
 return($ERRORS{CRITICAL});
 }

$temp=$handle;
 # remove eol chars
 chomp($temp);

print "sensor $_[0]: $temp degrees C\n";

# check for error code from temp sensor
 if (int $temp eq 85)
 {
 print "failed to read value from sensor $_[0]\n";
 }
 else
 {
 #Create webpage
 open WEBPAGE, ">$img/$_[1]"
 or die "Cannot create $img/$_[1]: $!";
 print WEBPAGE "$temp\n";
 }
 }

Links:

• http://www.temperatur.nu temperatures from alot of places in Sweden
• My info page at temperatur.nu
• Temperature graphs made by data from me
• The “webpage” that the script  create
• More information about 1-wire at this blog

2 Responses to “Temperature measurment for temperatur.nu”

1. Peter Says:
   February 22nd, 2010 at 9:16 am

   Hi Peter, I think you have to change the position of the temp probe, allways a few degree warmer than all our thermometers in Huddinge/Stuvsta.

2. peter Says:
   February 22nd, 2010 at 9:34 am

   I have noticed that asweell. The temp probe is probably to close to the house. I will look into that when the snow is gone 🙂

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