| hosting | contact

Temperature, Power & Environmental Monitoring

Now that many people have broadband, even if you do not have a static IP address (with a little free help from dyndns.org), it is easy to have your house's status available to you when away from home. Great for checking that the boiler is working properly in winter when pipes might freeze, or for ensuring that your refrigerator is keeping the beer cold. My system supports an ever-widening variety of sensors and data collectors, can alert you to "unusual" conditions (via email, pager, or syslog), and can even save you money! Find out how often your furnace or A/C is running, find out is the basement is flooding, if your computers are running hot, etc...

The software that logs the data and generates these graphs is free (Unix, Linux, Macintosh and Windows). Click on any of the graphs for an interactive view of the temperature, humidity, wind, power consumption, etc. in and around my house in Pittsburgh PA
I had a catastrophic server failure recently (the motherboard was fried, but the disks were saved and always backed up :-) last month, so only historical data is available at the present. The server has been replaced but is having issues at the moment... this is all being displayed from a backup server...

Today

This week
This month

Downloads
It's all free and written in Perl for Unix, Linux, Macintosh and Windows!

The latest version of the source code (version 2.x).

If you are upgrading from a version prior to v2.51, you may want this program to update your config file to the slightly revised format. The old format will work until I release v3.0.

Documentation (user's guide, configuration guide, and change log)
Startup scripts

For FreeBSD and NetBSD
For Linux (donated by Gerald Ruderman)

Other Tools

Thermdstats, a cool collection of PHP widgets (if you use MySQL for logging). By Chris Crocker-White.

If you want to switch from using flat-file logs to SQL logs, you probably want this program to convert thermd logfiles to SQL format.
The old (v1.77, no longer supported) version of the source code

If you are upgrading from version 1.x, you may want this program to convert the config file.

Support
I will try to fix any bugs that are reported to me. I am also open to the notion of a software support contract, but will strive to keep the software free and open-source (although there may be a "pro" version of the code in the future). If you have feature requests, I'm also happy to consider those!

The History of thermd

In 2001, I bought an inexpensive serial interface temperature sensor kit (about US$30) from QKits and after I built the kit, I also purchased an extra 3 Dallas Semiconductor sensors (another US$18). It was a very easy kit to build (it doesn't even need a power supply, it derives power from the RS-232 line it talks on), and the QKits folks are pleasant people to deal with. Then I wrote a nice Perl-based thermometer logging daemon, log grapher/dumper, and CGI script (one program does all three functions!). Over the years, I have continually improved the logging script, and have made it freely available to the public. This latest version of the Thermometer Daemon supports multiple data collection devices.

In February 2006, I decided I needed more sensors, so I changed thermd to support multiple QK145s and the newer VK011 from Quality Kits.
In March 2006, the very nice folks at Embedded Data Systems sent me an Ha7Net Ethernet 1-Wire Host Adapter and some sensors, and I have integrated them into thermd. Their systems are a little more expensive, but they are beautifully engineered, are quite rugged, you don't have to build them yourself (a big plus for business), and they support up to 200 separate devices (including switches, counters, barometers, light monitors, humidity sensors, LED readouts, etc.)
In May 2006, Midon Design sent me one of their TEMP08 Serial Interface units, so I have integrated it into thermd, too. One nice thing about the TEMP08 is that it natively supports the One Wire Weather Station and rainfall gauge from AAG.
In July 2006, SensaTronics sent me an EM1 Environmental Monitor, and that has now been integrated into thermd Their system is even a bit more expensive, but their product line includes cryogenic and high temperature sensors.
Also in July 2006, AVTECH Software sent me a Room Alert 11E, and I have added support for it, too (along with the Room Alert 7E and TemPageR) They are quite a bit more expensive, but have paging/alert software built-in.
I got listed on Hack A Day! (24 Oct 2006)
In December 2006, Geist Manufacturing> and IT Watchdogs gave me access to their RacSense and WeatherGoose products, and they are now supported.
In February 2007, MRV loaned me a MRV InReach LX-4008 and an IR5150, so support for that family of devices is online
SNMP-based devices are also now supported.
I got some gear from Hobby Boards to integrate with thermd, including the 6-channel Master Hub, and as of March 2007 (with some help from Lars Karlander in Northern Sweden), all devices supported by owfs and/or owhttpd are now supported by thermd!
I received an Enersure power monitoring system, and integrated it into thermd on April 15, 2007. So I am now happy to announce the addition of power-monitoring to thermd. I'm going to have to change the name of the program soon!
November 2007, I was contacted by HWgroup of the Czech Republic, and I integrated their Poseidon and Damocles systems into thermd. Thermd has also been internationalized, and currently supports English, German, Swedish, Spanish, Russian, Danish...
In the March 2008 release, thermd now exports data to Weather Underground as well as importing data for weather comparisons. Thermd also supports the notion of "actuators", so you can turn things on and off in response to temperature (or other) conditions.
In November 2008, Appled Power Technologies sent me a Veris Industries H8031 power sensor, and that is now supported in thermd, along with the H8030, H8035, and H8036.

I have a multi-axis feature and price comparison of all the devices that thermd supports.

Detecting Unusual Conditions with thermd

November 2007

Take a look at this graph. Notice how my 1st floor (cold air return) is very hot for part of of the day? It had me worried for a while... At first I thought that the cat sleeping on the air vent was diverting warm air around the corner to the cold air return, but when I went downstairs, there was no cat and warm air was gently blowing out of the cold air return. Hmmm...

I have twinned high-efficiency furnaces (a pair of 100,000 BTU furnaces tied together, both blow into the same plenum). One was having trouble starting (you can see that here, where sometimes the usage has a knee in the spike, and sometimes the usage is lower before I fixed the problem than after, but I only noticed that after I found the main problem). Each furnace has it's own cold air return, but both blow into the same plenum. If the main fan on one furnace doesn't start, there is blowback up it's cold air return from the other furnace's fan. That is what I was seeing – hot air coming out of the cold air return. So why wasn't the furnace starting?

To be safe, the furnace has a series of safeties. First, the combustion fan starts. If the prover circuit shows that air is flowing properly, then the pilot burner circuit starts. If the thermocouple shows heat, then the main burners start, and after the temperature rises, the main blower fan starts. Any single failure prevents the next system from starting.

When my gardener was here Tuesday afternoon (6 November 2007), he cleaned up the autumn leaves with his leaf blower, and some leaf fragments were blown into the air inlet pipe for the furnace. When the combustion fan started, it sucked in the leaves, which blocked the airflow, which in turn prevented the prover circuit from registering sufficient airflow, and so (sometimes, since the leaves moved around) one of the furnaces didn't start (or else it started late). And that accounted for the blowback.

Without monitoring, I would not have noticed this until the dead of winter, when the whole house was not heating properly. I would have wasted money on a half-functioning furnace starting and stopping, and I would have caused the working furnace to do double duty. With thermd, I noticed and fixed the problem in less than 24 hours.

| hosting | contact