No progress...on the electronics front

So here is a quick update...no progress...the spring seams to have arrived, so I have been taking care of the garden, and doing some seeding...now we have to wait for it to germinate!

I also have been taking care of the bike, which now has a complete set of new brake pads - note to self: do not brake too hard, since it will either damage the rear tire, or I'll end up jumping from the bike!

As for the house, I almost finished the roof insulation, with some little bits missing, awaiting for the new boiler to be installed in the attic, must contact an installer though. The savings might reach 50% with respect to the prediction curve!
I also found a modern, space-age material to insulate the floor with, which is light, easy to apply (stapling) and just creates some air pockets to prevent the circulation of the cold air. I might try to get it installed during the summer. I'll let you know more about it soon!

As for the electronics, I ordered and received some RFM12B transceivers, RFM01 and RFM02 transmitters and receivers from Lynx-dev.com, all went smoothly. Now I must get them to work with the arduino.
Also got a touchatag RFID reader, which I managed to get working on the mac, but not yet under linux. I want to use it independently of the touchatag service, in standalone mode, in order to do some more automation.

Meanwhile, the server is now up for 190 days!! What a victory!

Ambient orb for doorbell indication and electricity and gas consumption

Just a quick note to report on the progress of the ambient orb.
I coated the other half of the ball with white primer paint from a can I had laying around, and the results are really nice.
Take a look!


If you notice, on the left side, there is a little ear in the ball, so I'll just screw the ball to the drywall using the ear, install a microswitch opposite the ear, and it will be one with the wall. I reckon it will look good!

Now I will prepare the software for the arduino and the server, and when I reboot the server, I'll reinstall the whole thing. It might take a while, since, as you may recall, I am trying to go the whole heating season without rebooting the server that controls the heating, so far 163 days! But that allows me some more time to prepare the LED and think about the project!

Note: the reason why I can't disconnect only the arduino and install this without rebooting has to do with the (mine) crappy programming of the listener to the USB, which doesn't close the port. If I use Ctrl+C and disconnect the arduino, I'll not be able to connect to the arduino again without rebooting. I sorted that out in the new version of the listener, but, for the same reason I can't install it.

More on the consumption

The progress on the light to indicate energy consumption is going steady, but the camera ran out of juice, so I can't put a picture online. Maybe tomorrow.
So I decided to report to you about the consumption curves.
In the picture you can see a plot of the gas consumption versus the average monthly temperature for the last 3 years - 2006, 2007 and 2008. The "trendlline" is a excel computed trendline, and its equation for 2006 is my basis for the energy saving calculations.
In 2006 I did' have in place any energy saving measures for the heating, and a sinple manual thermostat, so I consider that to be the baseline against which all gains are to be measured.
I think the line approaches quite well the measured results. It is a second order polynomial equation.
Also in the graphic is the date for 2007, when my automated zone controlled system was already in place.it;s line is quite deviated from the line of 2006, so I can safely assume that there have been some considerable savings, and that my calculations might be close to the real thing.
As for the data points referring to 2008, these come quite close to the predication from the trendline for 2007, apart from the 2 slightly removed dots at the right. These correspond to February, when we spent a week off and therefore saved quite a bit on the heating bill, and December, when most of the roof insulation was already in place! Which makes me very hopeful that the insulation really is doing its job and saving quite some gas and CO2 from going up into the atmosphere!
Byt the way, for January, which just finished, I got a saving of 40% with respect to the 2006 equation, whereas in January 2008 and 2007 the saving in January was only about 12%.
I am hopeful to see what the coming months bring, with the added sun exposure hours (they do make a difference)!
I'll keep posting about it!

Log rotation

The heating system of my house creates a log file per week, per zone ( currently 3 zones: living room, kitchen and sleeping room). Every week, and on the same day of the week as the first day of the year, it starts a new log file. So to see the nice little graphs plotting temperature - actual and desired - and valve state, once a week, I have to ssh onto the server, manually adapt a little script and run it.
Until today!
I finally beat my laziness, and wrote a php script, took about 5 minutes to write. It is a brute force script just to get the job done. This to prove that a lot of time is wasted in activities that can very easily be automated and are of no interest to be kept manual.
So here is my script.
All, or almost all of my home automation run on php scripts being executed by a crontab.
Now, once a year I'll have to adapt the crontab file...maybe I should think about automating that also..

$comand = "rm kitchen.log livingRoom.log sleepRoom.log";
exec($comand);
$comand = "ln -s kitchen-";
$comand = $comand . date("Y-W");
$comand = $comand . ".log kitchen.log";
exec($comand);
$comand = "ln -s livingRoom-";
$comand = $comand . date("Y-W");
$comand = $comand . ".log livingRoom.log";
exec($comand);
$comand = "ln -s sleepRoom-";
$comand = $comand . date("Y-W");
$comand = $comand . ".log sleepRoom.log";
exec($comand);

and the crontab line

#once per week, for 2009 on thursday, first thing in the day, rotate the logs
15 0 * * thu /usr/bin/php /tmp/automate_log_change.php

New developments!

I decided that all the effort in measuring electricity and gas shouldn't go unnoticed in the house, so I decided to make a light indicating the status of the house. Furthermore, when arriving home, the only way to know if someone had rang he door was to check my intranet (on the iPod Touch), although, at work I can see it in twitter anyway.

So, I bought an RGB led, one with 6 legs - strange - the pinout is in the image. Some simple connections to the Arduino and a small fading program later, and I had an initial prototype.


My idea is to have a small switch connected to it to reset the doorbell indicator.

So on to the enclosure.
I had laying around a ball from some promotional thing, which splits in 2 halves. The ball is rather big - about 7cm in diameter - which makes it look good, and has a rough finish which is also good to difuse the light...although not good enough. So I tried roughing it further with sandpaper and some other mechanical tools, but no good result. The solution appears to be paint! - A light cover of white paint from a can.



I made all these experiments in one of the halves, now i have the other half to do the real thing. Hopefully soon!

3 years of gas consumption logging

For the last 3 years, since we have been in our current house, I have been taking very regular readings of the gas and electricity meter, usually daily, sometimes, skipping a day or 2. Recently, I have automated that process with the help of an Arduino and some additional electronics. That has removed the burden of collecting the data, and allows to see the evolution of the consumption to the minute! (note to self, explain the circuit to collect gas data!)
But all this accumulated data also has a good purpose, besides making nice graphics. It allows me to evaluate the measures I put in place to reduce the overall energy consumption.
In the first year, we only had an old Honeywell thermostat, manually operated. That was replaced in the second year by a fully automated system (see post regarding the uptime of the server). In the 3rd year nothing changed, but now that the 4th year is about to start, I am about to finish the roof insulation. All the accumulated data allows me to compare the increase in performance.
So here is a graphic of the monthly gas consumption for the last 3 years, along with the average temperature for that month as reported by the KNMI (dutch meteorologic institute) for Holland.

It is funny to see the relation to the temperature. In fact, from the data of the first year, I have managed to calculate a second order curve which relates temperature to gas consumption, so for a given monthly average, I can calculate how much the consumption would be. It is using this curve that I calculate my savings. I'll elaborate more on that soon.

Worth noticing is also the fact that December 2008 was much colder than December 2007, yet the gas consumption remained similar. I attribute that to the roof insulation, which I did mostly during November (not yet 100% finished).

More tablet news

Continuing, or better resuming, my activities with the tablet, I installed the bundled ArtRage, and I must admit I really like it...it is just a pity that I can't draw...But I'll use it for the future sketches of circuits.
I used it to make an icon for my twitter feed. I think it came out pretty good!

Hopefully more posts this weekend about the insulation and temperature controls!