How-to: RM read a value & set another value

[GatVlieg]

Is there any method to get a RM rule to read in the value of X & set that value X in another device?

Scenario: at 4:30AM READ in the current humidity reading of Motion#1, and SET that value in, say, a virtual thermostat. Bonus points for READING + 5 = new SET point. Currently I am doing this with WC but want to find a way to do so in RM. Using the new set point as a humidity trigger for the washroom fan.

Thanks
J

[SmartHomePrimer]

You can certainly do this with RM, and even enter an offset amount if you like. Use the Hubitat Virtual Omni Sensor to set your baseline humidity. However, as you'll see in the comments from @halfrican.ak in one of these posts, that method doesn't account for seasonal changes in humidity, so it's better to use a real second hygrometer with an offset value to set the baseline humidity. In the second screenshot, I compare against my Ecobee thermostat with an offset. What I'm not certain of, is if the offset amount should be positive or negative, but @bravenel can confirm, as this is not a real use case for me personally.

However, there are two community apps for this purpose that you may find of interest too.

Bathroom Humidity

OK guys.. Here is the first draft of the 'Super Smart Fan' If configured correctly it should: Turn on the fan when it's too humid (turning off when humidity returns to a normal level - based on a baseline sensor) Turn on with motion. - Turn off automatically after a pre set time period when motion stops (if humidity is normal) Turn off automatically after a pre set time period when manually switched on (if humidity is normal) You can find the app here: Have a thrash about…

and

Bathroom Humidity Fan

I converted a humidity controlled fan I used in ST to hubitat. it looks for a change in humidity and turns on the fan. You can set when it turns off to be byhumidity, set time, etc. I am using a IRIS Motion V3 to get the humidity. It also can set a timeout for how long to run the fan if it is manually turned on. Use Hubitat package manager to install But Code found here: https://raw.githubusercontent.com/napalmcsr/Hubitat_Napalmcsr/master/Apps/BathroomHumidityFan/BathroomHumidityChild.src …

[GatVlieg]

Hi

Unless I completely misunderstood, this is not what I want...

I want, as a True Action, do what you are doing in the Condition...

ie.
Trigger = At 4AM every day
Action = Set "Virtual Omni Sensor Humidity" to (Actual Humidity Sensor + 5)

I don't care if it takes more than 1 rule to do so, but I cannot find a way of doing the above...

And as you point out, one has to account for seasonal (daily!!) variance. In my case the humidity will be lowest at approx. 4AM, hence the reading for a baseline + 5 which becomes the new trigger for another rule...

Thanks
J

[SmartHomePrimer]

Just add the time as a condition

[GatVlieg]

Where / how are you setting your reference Humidty for a 4AM reading (the rest is easy & I am familiar with it)

Your example is correctly comparing 2 values, but knowhere, either in the same rule, or a different rule, is there a ACTION that sets the virtual humidity (the reference at 4AM) to (the actual + 5)

[SmartHomePrimer]

Maybe I'm not understanding your intent. I thought your end goal was to turn on a fan? Am I correct?

Here's how you set the second condition if that's not clear already.

[bravenel]

@GatVlieg

Action = Set "Virtual Omni Sensor Humidity" to (Actual Humidity Sensor + 5)

You are correct that this is not possible with RM. There are minor variants available, like following a dimmer, or tests relative to another device. But it is not possible in general to grab a value of one device and set another from it. Maybe in the future...