# Calculate with variables and values

Hello,
having some issue of understanding and need some help.
Here I want to describe what I want to do:
Get value from device a, get another value from device b.
Compare values and if difference is more than 5 do any action in the flow.

Any idea how to do that?

Kind Regards
Kai

Look for logic cards. See Switch floorheating pump on Evohome trigger

Only with build-in logic flow cards:

A numeric variable is needed. Here BeispielVariable.

If you need the result only for this flow, then you can use the app Temporary Variables and build-in logic flow cards:

No numeric variable is needed.

I guess there will be also a more professional calculation way, but it works.

On HP2023 also with normal flow:
(Picture below has changed after some comments below)

This is not the way how it works. Or I misunderstand what @kai.wagner.83 needs.

Example
The current value/temperature of Ingestelde temperatuur is 20 Ā°C.
The current value/temperature of Temperatuur is 24 Ā°C.
By adding 5 Ā°C to Ingestelde temperatuur (= 25 Ā°C), the temperature is greater than of Temperatuur (24 Ā°C), but the difference are just 4 Ā°C.

And this is what Kai wrote:

Hope itās understandable what I mean. But maybe Kai will explain in more detail what exactly he needs.

I think both solutions give a jump start for Kai to experiment and to find out what he wants and how to make the formula:

a-b > 5
a > b+5
a-5>b
Etceteraā¦.

Pls, donāt calculate every hour /minute / secondā¦ there is no need to it is the worst trigger they implementedā¦

Homey is build to:

1. trigger if something changes (Temperature1 or Temperature2)
2. something else that makes you need it. (Any other trigger, in an advanced flow when you need the result)

but why calculate something 1440 times a day while you probably only need it a couple of times, in my opinion thatās just a bad habitā¦

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I agree.
The short answer to the guestion asked by Kai is āuse logic card number 7ā. But as I donāt know Kaiās knowledge, I give a complete simple flow, to add some context.
In this specific case I better had the flow starting with āwhen this flow has startedā.
In the case where this example comes from, you finally need two triggers, change of actual temp and change of set temperature. You can do it in two normal flows or by one advanced flow. What ever the requester wants and is used to. But that is beyond the question being asked here. But I think I leave some points to find out by the requester, so he/she will learn. And not just copying ready to run solutions.

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Let me explain my intention:

I have got some tado radiator thermostats and some partly netatmo and some switchbot Meter Plus temperature sensors.
So I want to do the following:
If temperature on netatmo sensor is changing and the temperature shown of the netatmo sensor is more than 0,5 degree higher the tado thermostat should decrese its temperature.
So I want to keep the temperature near the temperature I decided to have in a room.
Same if it is getting more than 0,5 degree colder than set on the tado.

Maybe you can help me better now or understand what I need here

Thanks for your help so far

In the mean time I tried to build that on my own with help of some screenshot from @DirkG

Looking like that:

Wow, that is much more than I expected.
I think youāre on the right road, and I am not so good in reading flows. However you might add another trigger. Because the flow below shall be triggered as well as the actual temperature has changed as well as when the set temperature has changed.

I guess it will work. The only thing I would change is to use a timer app like Chronograph instead of the build-in delays. Because:
ā Itās not possible to stop or adjust the build-in delays (maybe not needed in this flow)
ā The Chronograph timers will continue after a restart (for what reason ever) of Homey, the build-in delays not

I use the build-in delays just for short periods, max. 1-2 minutes. But it depends also on the background of the flow, e.g. watering of the plants.
Example in your flow, if Homey ādiesā after Ausschalten, the heating will be turned off until one of the other flows set the heating again to Intelligenten Zeitplan fortsetzen, because the 60 min. build-in delay will be interrupted:

I am just trying to pass the current temperature to a variable and then to a notification but it so difficult to get any tips from the flows shown when they are not in Englishā¦ any tips on how to achieve this?

Hello Mark, welcome.

You can do this for example:
First create a text variable, I called it
āWeather temperatureā

The blue [Temperature] tag in the cards itās in, is from Homey āonboardā weather, you can select it like this:
Inside the (timeline) card, click the ātagā icon on the right hand side
Then you can pick the Temperature tag:

.
Also donāt forget to search the knowledge base, thereās lots of info available:

Peter,

Thank you so much for your assistance.

However I am having great difficulty in followingā¦

1. Only one of the screen shots is active.
2. The 'Then - Calculateā¦ card requires numeric arguments but you recommended creating a text variable.

Sorry for the troubleā¦

Regards,

Alsoā¦ Iāv been searching for hours for the internal (i.e. āonboardā) weatherā¦ I cannot find it anywhereā¦

Regards,

My pleasure, Mark.

Awwww my bad, for some unknown reason
I wrote ātext variableā, but it should have read ānumeric variableā.

BTW you can determine the var type by their color.
Blue: num
Green: text
Orange: bool

.

A screenvid says more than screenshots/words

Thank you for the informationā¦ I finally stumbled through (with the help of your single screen shot) and now have it working.

I have previously setup my whole smart house using Hubitat but I am now in the process of converting everything to Homey Proā¦ a sometimes challenging task.

Thanks again!

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