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Temperature controlled relay (help needed for noobie)

Former Member

Hello, my name is Aisha this is my first post and I am excited to get into the community.


I live in a studio apartment with my wife. The entire apartment is on a 15amp breaker so we have to be careful about power use. We find if we run the A/C and cook something in the kitchen the fridge will kick on more often and trip our breaker. We have a blower to pull hot air out of the kitchen and I would like to use an arduino to turn it off and on based on the temperature.


I have:

 

an arduino uno

a tmp36 temperature sensor

a 5v arduino relay module

a breadboard and leads

 

I want to do this not only the right way and the best way with what I have available. I have used the arduino to switch the relay using the blinking LED code from a kit I got. I have wired up the sensor and read readings off of it.

 

 

The tutorials I find online say I should connect it to 3.3v and also AREF to 3.3v when I do this I don't get 3.3v in my serial monitor like the tutorials say but 1.5 (average). I am left lost as no tutorials show how to do this without an LCD screen and with a relay module. I don't need to monitor the temperature after I have it set properly once so an LCD is unnecessary (though I would not mind being able to add on in the future.)

 

I plan to put the sensor on a cable, are there limits to how long a cable can be for this sensor? I was planning on using cat5 cable.

 

So far all of my experiments with arduino involve copy pasting code and maybe modifying a couple lines that are clearly labeled or that a tutorial has told me to edit. I have 0% skills and about as much understanding and confidence in coding anything let alone a micro controller.

 

I have seen people adding things like data logging to increase accuracy of readings and delays to keep the switch from tripping like crazy but again I'm still struggling with the hardware and code is not at my level yet.

 

Hopefully there are people who can help me out. I know this is super easy for anyone who knows how to use and code arduino, I just need some help getting my first project finished.

Parents

  • What had not been said yet is the issue of driving mains with an arduino relay board.

     

    They are not all created to handle mains . Even if the physical elay is capable. The board may not be and mistakes with mains can be rather unforgiving

     

    Don't know you expertise with mains control but if not much then seek advise here before you attempt it

     

    You can of course go right ahead and drive the relay board from the ardiino , just don't connect mains unless your sure.

     

    Many of these boards are designed for only 24v but still have 240v relays on them. So don't think is still safe just because the relay says so

  • in reply to Robert Peter Oakes

    Good point, Peter. I was suckered into buying such a relay board ( such a pretty blue colour; matches the Arduino!! ) early on in my Arduino experiments - I haven't used it to switch 240V !

     

    Neil

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