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

Now with the minicomputers like Asus EeePC Linux is widely used by non computer geeks and for “normal” humans it is as easy to use as Windows.

Read the article in Swedish here.

On the picture Johannes Dagemark, op5 CTO can be seen. The article describe how an organisation or enterprise can save money and achive higher security with OpenSource.

One example is the Swedish police that estimates their savings to 25 Million Euro every year.

Link to the article written in swedish