Platform information: Hardware: Laptop OS: Ubuntu 19.10 Java Runtime Environment: idk openHAB version: 2.4 Ive been reading up on this topic to get close to my goal. The idea is that when the temperature drops below 0 degrees it will give me a push notification, telling me exactly that. And wh…

[image] Kimzer: [INFO ] [marthome.model.script.Outside_Temp: ] - 6.0 °C Okay, I don’t know how you formatted the logInfo() to produce that now - but I will guess that it wasn’t you that added °C The implication would be that your Item has units of measurement, UoM, and is not just a number. …

Firstly, what you’re doing now is notifying if the temperature is above zero, not below. What you could do is something like if(Outside_Temp.state < 0 && previousState > 0) This way you will only get a notification if the current reading is below zero and the previous one was above, this should m…

[image] Kimzer: logInfo("Outside_Temp: ", temperature.toString) You put that in to provide useful information - may we see that? (openhab.log) [image] Kimzer: And obviously the alerts get spammy as any change in temperature will give a push notification as it is now. Yes. What would …

I guess every time it changes from 0 to below zero would be ideal, and somehow prevent spamming if its just hovering around the mark. Tried this, but it does nothing. No log entry at all. rule "Outside_Temp" when Item Outside_Temp changed then if(Outside_Temp.state < 0 && previousState > 0) { sen…

It does nothing because you wanted it do something only when the temperature is below AND above zero, in can only be either OR!

i am manually posted via mqtt to say that the temperature is above 0. So when the real temp is read in, i thought it would catch that and give me the notification?

Ups, I’m sorry but I misread the if statement (missed the “previousState”) :smiling_face: It is too early for me I guess. Try to put a logInfo before the if statement in order to see if the rule gets triggered at all.

In a real situation before going under zero it’s likely that the temperature IS zero, so you have to also catch the previous state to be equal or greater than zero.

There are a few challenges/potential pitfalls to deal with in this seemingly simple scenario… :smiling_face_with_sunglasses: Depending on the accuracy and frequency of reported temperature by the sensor, there can be a flip-flop scenrio where the temperature goes to just below and just above zero …

[image] noppes123: If I’m not mistaken, previousState gives the last persisted state and not necessary the last changed state. When you use Item xxx changed as a trigger, previousState is an implicit variable holding the Item’s state before the change, even if no persistence is configured. So…

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[SOLVED] A rule that tells me when the temperature has dropped below 0 degrees

Setup, Configuration and Use Scripts & Rules

rlkoshak (Rich Koshak) November 3, 2019, 3:16pm 4

For an example of Daniel’s suggestion, see [No longer relevant on OH 3.0+] Design Pattern: Rule Latching.