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Topic: Heating Control Solution- Help Needed! (Read 2033 times) previous topic - next topic

zooboy

Hi all,

I am currently looking for a heating control solution for the zoo I work for that is fairly specific in its requirements which are not being met by any one product that I have managed to find to be available at this time. I've come to the conclusion I'll have a go at creating something for myself!
This is where I am in need of help: I was hoping someone would be able to point be able to share any experimentation they have explored in this vein or point me in the right direction so that I can achieve the following:
•   Ability to download a 12 month temperature variation + day/ night settings to a controller
•   Control a heater up to a maximum load of 2 kW
•   Display to show the variables
•   Sensor for both inside and outside T°C so that the heating can be turned off if the temperature outside reaches a certain point with two different critical points.
•   Option of one (or multiple) input for occupancy detection to control on/off (or adjusted heating)
•   Output to be a variable, "pulsing" power so as to maintain a constant temperature rather than on/off
•   Potentially - to record the Energy Consumption?
•   to store the data on removable memory card

A pretty specific list, for which I apologise! I hope someone - or a few of you - have some ideas/ guidance/ help for me with this.

Thanks in advance!

groundFungus

You have already broken the problem down into pieces.  Tackle the pieces one at a time.  Each piece is not so difficult once you decide on hardware.

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Ability to download a 12 month temperature variation + day/ night settings to a controller

How large is the data file?  Perhaps store on a SD card?  You will need to learn to interface the card hardware and understand the software to access the card.

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Control a heater up to a maximum load of 2 kW

Learn to control mains powered device. Maybe solid state relay?

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Display to show the variables

Decide on a display.  1, 2, 4 line LCD, graphic LCD?  Again learn interfacing and software.

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Sensor for both inside and outside T°C

Decide on temp sensors and figure out how to read and convert the output to degrees C.  DS18B20 is very popular and you can hang a bunch on a one wire bus (something else to learn).

And so on.  Once you have the pieces study Finite State Machine.  Use a FSM to build your program from the pieces.



Bainesbunch

Hello,

OK so the simple answer to your question is YES it can be done.

I have developed a tortoise environmental control system for another client that wanted to be able to monitor and control the heating and ventilation of his tortoise house. The system also used RFID tagging to be able to tell which and how many tortoises where in the house so that it could be locked up at night to prevent predators entering. It had the ability to run a temperature matching pattern where it would adjust the internal temperature according ot the outdoor temperature to follow a predefined pattern stored on an SD card. it was only able to follow the curve to a resolution of 15 mins. given the hysteresis of the change of temperature and the resolution of the PID used to control it this was sufficient for him.

The system was monitored through a web interface on the master system and used radio link to the actual tortoise house.

What is your budget & timescale for this project.

Take a quick look at my website (WWW.EmbeddedAT.com) to see the other sorts of projects I get involved in and if you think my skills are a good match for your requirement or even for a chat about options please drop me an email.

Cheers Pete.

EmbeddedAT .. From Concept to Prototype to Production
Electronics and firmware design and project mentoring
I do answer personal requests for help when accompanied with a PayPal receipt ;)

Henry_Best


•   Option of one (or multiple) input for occupancy detection to control on/off (or adjusted heating)

Ants or elephants?

zooboy

Okay so I've done some reading and am growing ever more enthusiastic about this project. I have a million questions but I'll stick to just a couple for now:

Starting from the very beginning - What Arduino board would I be best using for this?

Regarding the nuElectronics Datalog + I/O shield - which I think would serve me well after reading up on the use of DS18B20s with it- is it possible to both read AND write off of the SD card with this shield?

Or do you feel there is a better fit for my needs than that shield?

Thanks!

Bainesbunch

#5
May 16, 2014, 01:09 pm Last Edit: May 16, 2014, 01:12 pm by Bainesbunch Reason: 1
OK if you are going to be building this and are prepared to use shield then just go for any SD card reader breakout board that is Arduino compatible. You dont need to g  to the expense of a full blown shield for this.

This will do you just fine http://www.ebay.co.uk/itm//251532571285

you will need to wire up the SPI interface yourself but there are plenty of good references out there for that.

As for the Arduino board then just go for the mega. It will offer you lots of IO and has a good sized program memory  and RAM. If RAM is high on your list however go for an ATMega1284P device like the BobDuino. Or get out the breadboard and build it yourself

Cheers Pete.
EmbeddedAT .. From Concept to Prototype to Production
Electronics and firmware design and project mentoring
I do answer personal requests for help when accompanied with a PayPal receipt ;)

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