Yes, it would make things much easier if this would be possible without the need of using YAML.
It would be even more useful if you could also calculate with static numbers, like (15 - sensorValue) / 100.
As a Home Assistant beginner I would like to be able to sum two sensors into one value an hope this will be added soon into the helper section. Adding it by using yaml code is so not very convenient. Please add this feature as I thing this should be a basic function.
It’s working great! I’m using it to sum some WSDOT trip time measurements for the freeway routes between our company offices since they only provide the values on a per-segment basis, but I need it on a freeway exit-to-exit basis.
Like any other entity, it starts recording its historical data at the time you create the helper rather than just being a passthrough of the preexisting historical data from the entities that are being used for the sum. (That would have been amazingly neat, but I suspect it would be difficult to do efficiently.)
It would be nice to have subtract… or the ability to include any kind of manual/static values rather than only including references to entities. One could make a helper that contains a negative number and then include than as part of a sum. It’s a workaround, but that could probably work? (she says, not having tried it… )
I tried make helper with constant negative walue… wihtout success.
But I made some trick.
I made virtual mqtt sensor.
Usine MQTT Explorer i publish topic with negative value. (Remember topic must have Retain Flag).
Next, I made sum with my sensor.
It’s work but need a lot of work. Aubstract with constant value should be much simply