As we have bought a new house with a basement, and we plan to put our chest freezer there, I started worrying about the time it would take us to notice a malfunction in the freezer, the lid left ajar, or a power-outage while we are gone. I decided to monitor the freezer with the following setup:
- A dedicated "server" (currently acer one running ubuntu desktop, but I'm thinking of changing that)
- "1-wire" temperature sensor DS18B20 and 1-Wire USB Adaptor from Hobby Boards
- owfs filesystem to poll the sensor
- thermd to log the data, present it in a website and issue emails in case of problems
- sSMTP on the server to take care of the email.
- DNS records updated using a DreamHost hosting and No-Ip free DynDNS service
- apache2 Server to serve up the website
I'll try to record the steps I took to make it easier for me to do again, and for others to emulate...
2. I installed owfs by downloading and running configure && make & make install. this had some errors as long as I didn't have enough packages installed...so I installed them using apt-get install.
sudo apt-get install libfuse-dev libusb php5 php5-dev ssh build-essential libusb-dev make libgd-gd2-perl libhttp-date-perl libconfig-general-perl libgd-graph-perl
I added the command
/opt/owfs/bin/owfs -u /mnt/1-wire/ --allow_other
to rc.local so that it is started up everytime I booted.
3. At this point, I could already see the sensors:
~$ ls /mnt/1-wire/ 28.06F625030000 81.7F9230000000 alarm bus.0 settings simultaneous statistics structure system uncached ~$ ls /mnt/1-wire/28.06F625030000/ address crc8 family id power r_id temperature temperature11 temperature9 templow alias errata fasttemp locator r_address r_locator temperature10 temperature12 temphigh type ~$ cat /mnt/1-wire/28.06F625030000/temperature -21.1875
Telling me that the current temperature (inside the freezer) is -21C.
4. For logging this data I downloaded thermd. to install it a few perl packages are needed so I installed them (again using apt-get). After editing the configuration file and putting it in its place ( /etc/thermd.conf ) making a directory for the datafiles (mkdir /var/log/thermd ) and copying the script to its place ( /usr/local/bin/thermd ) one can run it
I then added that line to the /etc/rc.local as well.
5. I changed the hostname in /etc/hostname (to snowy) and added a line in /etc/hosts:
192.168.15.7 snowy snowy.
Since I decided to name the machine snowy and I've decided on the fixed internal address it will have on the router.
6. The router also needed to be told to route port 22 and 80 to that machine.
7. I opened a free "no-ip" account and created a hostname snowy-farjoun.no-ip.org pointing at snowy. I also installed the client on snowy (apt get didn't work so I did the other way). on my domain registrar I added a CNAME entry pointing from snowy.farjoun.org to snowy-farjoun.no-ip.org. I tested this with ping (I think).
8. sshd needs to be installed (for remote administration) apt-get install sshd (probably needs hardening..but "I'll do that later")
9. The computer needs to be told not to use DHCP, what are its address, router, network mask and some DNS servers.
10. apache2 was installed (apt-get install apache2?) and configured the default site in /etc/apache2/sites-available/default: (only changes shown)
ServerAdmin <my gmail address> ... ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory>
At this point, the website should be visible. Check /var/log/apache2/error.log for hints if it isn't working.
11. For mailing me when alert conditions happen I installed sSMTP ( apt-get install ssmtp ) and configured it with the following configuration file:
~$ cat /etc/ssmtp/ssmtp.conf mailhub=mail.farjoun.org:465 UseTLS=YES # Secure connection (SSL/TLS) FromLineOverride=YES # Force the From: line Hostname=snowy.farjoun.org # The name of this host RewriteDomain=farjoun.org # The host the mail appears to be coming from Root=yossi # Redirect mail for root@ to postmaster@ AuthUser=mySMTP User # Your DreamHost mail account AuthPass=mySMTP Password FromLineOverride=YES
I tested the email configuration using thermd -checkconfig -email verifying that I got an email from the daemon.
TODO: add a ping from my hosting service to see if snowy is alive...email me if not.