Temperature Control

This is a question about “general approaches and feasibility”.

I used to do VB programming, but the rest of this is all new to me.

I need to accurately control the temperature in a room, where day-old chicks are housed.
I’ve come to the conclusion that I can use Arduino for this (together with a few LM35 temp sensors,
a picaxe-serial LCD module, an AZL relay board 4ch 5V Arduino, a small 12V waterpump, and a Hi speed 12V DC fan). I would also like to plug in a network cable, to see what is going on, on my laptop about 50m away.

My algorithm looks like this:

If InsideTemp < 32°C then
If OutsideTemp > 32°C then
HeatingFan On, WaterPump off, Heater Off, Alarm Off, Beeper Off, CoolingFan off
Elseif WaterTemp > 32°C then
HeatingFan off, WaterPump on, Heater Off, Alarm Off, Beeper Off, CoolingFan off
If WaterTemp < 45°C then
Beeper on
End if
HeatingFan off, WaterPump off, Heater On, Alarm On, Beeper Off, CoolingFan off
End if
elseif InsideTemp > 40°C then
HeatingFan off, WaterPump off, Heater Off, Alarm Off, Beeper Off, CoolingFan on
HeatingFan off, WaterPump off, Heater Off, Alarm Off, Beeper Off, CoolingFan off
End If

I would like to see on the LCD module, and also on my Laptop:
OutsideTemp, InsideTemp, WaterTemp, and the status of everything that can be on or off.

I have not bought any hardware yet. Any suggestions, comments or advice will be highly appreciated.

From a feasibility viewpoint I think that this is totally doable. The only thing I had to think about for a bit, and actually still don't know the answer to, is whether or not it will be possible to attach a 50m cable to the arduino and print out the information (I was thinking a usb cable and serial.print). I remember extending a basica webcam with a 4 meter cable and it did not work properly anymore, but I am no expert so I have no idea if it might actualyl work after all. You would have to look that up.
I am guessing you will be using the relay board to control the fan and such which will work without a problem. Just make sure you don't connect the pump and such directly to an arduino pin. The use of the relay board is good here.
Using the temperature sensors is also possible. If you are not a pro at using the mentioned items then libraries will definitely help you. I think the challenge will be reading the temperature (although this is quite simple using a library).

Printing the information will work no problem. i am assuming the lcd will be connected to the arduino and not be 50m away. You can use a library for this as well. Alternatively, and this is what I do with lcds, you could get an i2c backpack so that you can use i2c to print stuff to the lcd. I just find the wiring that much simpler, plus you have more pins for other stuff.

And as you are familiar with programming in general, implementing your algorith should be simple as well. After all, you have pretty much already done so...

If you don't have a problem with libraries (some people do) then I would start by getting one for the temperature sensor and the lcd (I think there is one for the lcd in the Arduino IDE, LiquidCrystal or something like that). Controlling the relay board should just be writing pins high and low I would think. The algorithm itself should be easy.

One thing you might want to look into is having a PID loop for your temperature control, so that the relay does not constantly go and off if the temperature is right on the on/off edge. Don't know if it matters too much though and I probably would not have implemented this myself. At least not at first.

So anyhow, I know my reply is not very detailed, but I thought I'd just give you my thoughts on your project in gerneral. It certainly is doable and should be quite fun as well.