The Temperature At Home
These temperatures were measured by a Hot Little Therm attached to a
serial port on my PC, running Linux. There are currently 4 probes
attached, two in my study, one outside my window and one in the
compost bin.
The temperatures are sampled every 5 minutes or so. The most
recent set of readings (and the charts below) are
uploaded to this page every time I dial into my ISP.
Note: Gnuplot doesn't seem to like plotting across year
boundaries, so only readings taken since 01/01/98 are shown. There are
also gaps in the data, caused by my cat chewing through the HLT
cables. Both cat & HLT survived.
This page is organized into the following sections:
I've also written some Linux based driver code for X-10
devices. See here for more details.
The Latest Readings
The last readings were taken on Wed Dec 16 22:43:01 GMT 1998. They were:
- Outdoors: 4.6
- Indoors: 18.4
- Indoors spare (various hot/cold drinks, parts of my body etc.): 15.6
- The compost bin: 15.6
Temperature Charts
These were produced using gnuplot. The
charts show the indoor/outdoor temperatures for the last 24 hours, last 7 days, and
for everything thats ever been measured here
(since the last head-crash, that is).
The Last 24 Hours
The Last 7 Days
Everything Thats Ever Been Measured Here
The Temperature In The Compost Heap
I'm even measuring the temperature in the compost heap! The probe &
lead are taped to a sharpened wooden stick. This is rammed about one
foot into the heap. The temperature is then logged as described above.
Min, Max, Average Readings
A plot of the minimum, maximum & average daily outdoor
temperatures, computed at midnight.
Tcl/Tk Wish Interface
I've written a Tcl/Tk Wish program that displays one or more probe
temperatures in real time on a X11 display. It does this by polling
probes at regular intervals. Check out the screen
dump for an idea of what it looks like.
The wish script relies on a command line program (hltcln)
to read the probe. This can be found in the source
code. With a little work, the script could be modified to
eliminate the call to hltcln by fiddling with the serial
port directly (using stty/cat etc. This would make the wish
script completely stand-alone.
Source Code
The source used to measure, log, chart and display the HLT readings
can be downloaded from hlt.tar.gz. This is a
tarred, gzipped file. If your browser can't download this, try this directory instead. The source code consists of a
mixture of C++, Tcl/Tk, shell and gnuplot scripts. There's nothing
particularly ticksy in it, so it should work on most flavours of
Linux. Mail me if it
doesn't. The code is not very well packaged, documented or
configurable. You have been warned. If enough people are interested,
I'll try and fix these shortcomings. I've written the rudiments of a
README file. When I get motivated, I'll
build it up some more.
You are free to do what you like with the source. Please let me know
of any errors you find or modifications you make. I offer no
guarantees, warranties, liability etc etc. You're on your own!
I've made quite a few minor enhancements to the software since it was
last uploaded. For details, mail me.
Webring
A ring of other Home Automation sites.
$Id: temperature_html.tmpl,v 1.18 1998/04/05 21:13:51 lsmithso Exp $
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