Electronic – arduino – Is Arduino a good platform for monitoring 24VAC thermostat circuits


Our house has 4 heat/cool zones, controlling two separate furnace units. I'd like to build a system to log on/off times for each of the zones and the burners/compressors. This makes a total of 10 inputs. Is arduino a good platform for this type of application? I have plenty of software experience, but limited hardware design knowledge (but I am comfortable with a soldering iron if I know the required design). I would probably ship the data (input#, new state) to a nearby server using TCP or UDP to be logged.

Best Answer

It's perfect. I did this exact thing in my house. I used an MID400 optocoupler to turn the 24VAC present across the terminals of the thermostat (at the furnace end) when the thermostat is NOT calling for heat into a digital high at the Arduino. I'm using an XBee network, but Ethernet (or even a tethered computer) would work just fine, too. It'll work for higher voltages, too.