Topics > Home Automation and Networked Objects

Arduino + Raspberry Pi Thermostat and Zone Control -- Need Guidance

(1/3) > >>

jgiebler:
Hello Fellow Forum Members,

As a Pre-cursor to the below post. I DO NOT HAVE ANY CODE as of yet. This post is exploratory and research based at the moment.

I have a desire to do an Open Source "Nest Alternative".

Here is some project background:

I would like to do HVAC Control as well as Zoning Control with the R-pi as the "Brains"
I would like to use the Arduino for Servo Motor Control and Temperature Sensors (Possible "Motion" Sensors as well)

My Understanding of Zoning
[*]Each room in a house is a "Zone"
[*]Each zone is 'Independently' controlled by temperature sensor.
[*]The Zone's HVAC Registers are opened or closed (Partially in some cases) to control room temperature

I believe that this project will do two things:
1) Allow me to have a "Learning" Thermostat (Powered by R-pi) that is web-based and open source
2) Save money by only cooling/heating "Occupied" portions of the house

So far I have gathered some information from these websites:
http://www.plainlystated.com/2011/07/building-a-thermostat-using-arduino/
http://diy-zoning.sourceforge.net/index.html
http://www.homeclimatecontrol.com/adk
http://androidthermostat.com/
http://forums.trossenrobotics.com/tutorials/how-to-diy-128/get-position-feedback-from-a-standard-hobby-servo-3279/

I believe the R-pi has enough I/Os to control the Relays for the actual HVAC. It looks like I will need 4 relays for my house.
I plan on then connecting all of the Servos and Various sensors to one or more Arduinos. The R-Pi and the arduino(s) will be about 20m apart. (Arduinos will be mounted in bedroom closet, R-pi will be on the wall in living room)

I would also like to have a Touch Screen for the HVAC Controls connected to the R-Pi.

My Questions to this Community.
1) What pitfalls am I missing? Will I destroy something??
2) Has anybody done this already (No reason to re-invent the wheel)
3) What is the best way to do R-Pi <-> Arduino Communication (uART,Serial, RS-485, IP, etc)
4) Any Recommended Components?
5) Where should I put the Sensors for each room?
6) What does it take to build a thermostat circuit? Any other project links would be great!
7) Anybody else interested in getting involved?

Thanks so much for taking the time to read this!

AJB2K3:
Have you checked out the RPI web site?
there are already expander boards for the Io's

Im actually interested in this, to see what Ideas I can get for modding my central heating

westveld:
I'm looking into the same thing - my thoughts so far -

My Questions to this Community.
1) What pitfalls am I missing? Will I destroy something??
I'm thinking of leaving the main thermostat in-line with the new controller - maybe set to 80 degrees?
That way if the new controller fails in some way, it won't keep the heat on.

3) What is the best way to do R-Pi <-> Arduino Communication (uART,Serial, RS-485, IP, etc)
i2c ?
http://blog.oddbit.com/post/i2c-on-the-raspberry-pi

Kong:

--- Quote ---6) What does it take to build a thermostat circuit?
--- End quote ---


For my project, in each room (zone) I installed a Honeywell Round on/off thermostat (T87G1006)
It's a power stealing thermostat, so no batteries needed.
I've made a small circuit to give a signal to the input port of arduino.

The benefit of this, is that I don't necesserally need a tablet to control the heating system, also I see the actual temperature on the thermostat.
The best way for mounting a thermostat/sensor: ca. 1.5 meters above floor, watch out for draught and lightbulbs (warmth).

spumanti:
Sounds interesting.

I am also thinking about creating something like your setup in my house.

[font=Verdana]3) What is the best way to do R-Pi <-> Arduino Communication (uART,Serial, RS-485, IP, etc)[/font]
For my project I was thinking UART, as it is easy to expand by simply dropping in some xbee modules.
They will directly accept UART communication, making the arduino sub-stations wireless.

! ! ! Please be aware that the RasPi is a 3,3v device, and (depending on the version) the arduino is a 5v device. before you connect the 2, you MUST use a level converter, or you risk frying the PI's IO ! ! !


I found some inspiration here:
http://www.fritz-hut.com/arduinopi-web-based-controller-for-arduino/
that I'm trying to recreate.
So far i managed to get commands sent from the PI's web interface to the arduino using UART, and also using UART+Xbee.

I am nowhere near a working solution yet, so its great seeing others wanting to create something similar

Navigation

[0] Message Index

[#] Next page

Go to full version