Thermostat & Arduino

[vidarr]

Hi, I have these two thermostats removed from an air filter with dehumidifier and another from an air conditioner and was wondering if they can be used with an Arduino. I looked up the thermostats and just got general information, nothing technical, or datasheets.

Searching Arduino forums only brings up other thermostats and hygrometers mostly sold by adafruit. It almost seems like only certain thermostats are compatible with Arduinos, but that is the question.

The two I have are:

VIT-300 E218405

and

E248681

The E248681 has two sensors on it and I think one (the silver cylinder) may be for humidity, which would be great.

I am finishing up a five channel relay circuit and would like to get the thermometer and hygrometer designed, built and plugged into the circuit next.

Thanks!

[brucehoult]

They are just thermistors. i.e. resistors that vary with temperature.  No doubt there is a spec somewhere, but I'd just measure the resistance at room temperature (or whatever temperature points of interest you have) and make a voltage divider using a similar value fixed resistor, and measure the resulting voltage using the Arduino's ADC.

[vidarr]

OK, got it. So kind of like a photoresistor. This is good news. I was hoping someone wouldn't tell me I need a special driver board built for the "thermostat" ---it is a thermistor.

Thank You!