House Temp Project
From DigitalSoup
Contents |
About
Last winter I was looking for ways to cut down on my heating bill by measuring and controlling my heat usage relative to the inside temperature, outside temperature, time of day, physical location, and a number of other variables. The goal was to then create a far more efficient thermostat specifically tailored to my individual use.
Build
In order to gather data and cause the furnace to fire, I needed to build two boards:
- Temperature Logger Board - for recording the temperature
- Relay Board - for turning on/off the furnace/blower/(AC in the future)
I found a couple kits online and soldered everything together. I then put them in some cases to make it a bit more professional
It was then a matter of wiring up the sensors inside/outside and hooking up the relay to my furnace. (There were a few warnings on the furnace I had to ignore :-)
Software Development
Once I had all the hardware set up and working properly, it was on to the software development. The first step was to write some basic drivers to talk to the hardware. With the help of some open source code, this was pretty simple. In short time I had the temperatures of my livingroom and front porch printing to the console and I could command the furnace to come on/off.
Now that this was done, I wanted to be able to capture temp data in a way that it could be stored and easily reviews (pretty graphs). I did this by logging the temps into a mysql database every 15 minutes. I then used jgraph and some php to generate real time custom graphs of the temperature data.
I then toyed around with controlling the furnace over the web, and using the actual temperature data to command the furnace on and off. However, without extensive testing I have no yet gotten this working in a production system. (Don't want to burn down the house by accident!)
Future Goals
I hope to get the system working in a reliable and secure way by the end of Winter 09/10. Additionally, I have toyed with the idea of installing automatic vents that can open and close. With this in place, I would be able to control the temperature of different rooms and not waste energy heating rooms that aren't in use. (Ex: at night the livingroom doesn't need to be heated but my bedroom does)
