Temperature Delta Indicator

[muchasimo]

Hello Hubitat Community!

I just installed a Fibaro Smart Implant, with two temperature sensors, into my furnace to monitor the input and output temperatures across the heat exchanger. I have them being displayed in my Dashboard, but I'd also like to put in a tile that shows the (absolute) delta temperature. Is there a way to create a virtual temperature sensor that is the (positive) difference between the two physical sensors? I say positive because I want it to display a positive value whether I'm in heating mode or cooling mode.

I can't figure out how to compare two temp sensors and show the difference in another virtual device. I don't have Webcore installed, but I will if this is the way to do it.

I appreciate the feedback! Thanks!

[sidjohn1]

[UPDATED] - Average All (Temperature, Humidity, Illuminance, Ambient Pressure & Motion)

I found a need for an app & driver to 'average out' temperature, illumination & humidity. So here is a little app and a couple of device drivers to do just that. This is a parent/child app so you need to install both parts before 'loading' the parent . This also comes with three virtual device drivers so you can create virtual temperature, illumination & humidity devices for use in other apps. After installing the parent you can create as many of the child apps as you wish (You need to creat…

[muchasimo]

Thanks for replying! This isn't quite what I wanted. I'd like to get the difference between two sensors, not the average of them.

I appreciate your time, though!

[aaiyar]

This is fairly simple to do with rule machine, and hub variables. Here are the things you will need to do:

1. Create two decimal variables corresponding to each of your real temperature sensors, and a third hub variable corresponding to the temperature difference. Create a temperature sensor connector only for the third hub variable.
   

   

2. Create a single rule in rule machine that will run whenever either of your two real temperature sensors changes value. This rule sets the value of each of the two variables to the value of the real temperature sensors, and the third variable to the value of the difference. You have to use the variable math function. Here's the rule:

If you open the virtual temp_diff temperature sensor, it will display the value of the difference. You can also use that in a dashboard etc. etc.

[muchasimo]

Yes! Thank you! This worked perfectly! I added one more step to get absolute value of the difference. I never knew about the global variables. This opens up another world of possibilities.

Thanks again!