Washing Machine working minutes

[rkrisi (Kristof Rado)]

Hi Everyone!

I’m using succesfully this approach:

Washing Machine State Machine

By following this tutorial, you will make your openHAB setup aware of the current operation state of your washing machine, dishwasher, dryer, toaster, doomsday machine, you name it. This solution is purely based on a power usage reading by one of the many available modules. The solution will allow you to react on certain state transition, e.g. sending a notification to your smartphone: “Washing machine is finished!”. [image] Requirements power consumption measuring device, e.g. Homematic HM-E…

However I want to view how long does the Washing machine is running since the Active state.

I thought storing a DateTime item when it changes to Active, but how should I calculate the timespan between that DateTime item and now? And view this (minutes mainly) in a String type item?

Thanks!

[rlkoshak (Rich Koshak)]

I’d set up a Design Pattern: Looping Timers that runs over pet minute counting up the minutes. Start it when the activestate starts and stop when it’s ends.

[rkrisi (Kristof Rado)]

Thanks!
I want to do this in Python. However a simple loop is not looking very good I think. It would be better with a Timer? How could I do that in Python? Just do it how the usual Rules DSL pattern goes? Global timer and start it if the timer is null (None in Python) and clear the Timer when it is over?

[rossko57]

Are you trying to provide a live display, e.g. minutes counting up during use?
Or just a total after it’s all finished?

[rkrisi (Kristof Rado)]

I want to provide a live overview of the passed minutes since ‘Active’ state, because I might approximately know when it will finish. (So just storing the Start Date and End date and extracting them is not enough here).

[rossko57]

Well, in DSL the most efficient way is to Rich’s pattern. A recurring one-minute timer increments a counter.

But you want to use python, so no idea.

[rkrisi (Kristof Rado)]

Yes, that’s my problem. And I think an ‘active’ loop is not a good solution in any language…

[rossko57]

Rich’s solution is not an active loop. It does nothing most of the time, then spends a millisecond or three updating a counter once a minute.

[rlkoshak (Rich Koshak)]

@rkrisi

I want to do this in Python. However a simple loop is not looking very good I think. It would be better with a Timer?

There are Python examples at the supplied link. What is wrong with a loop? But if you’d rather implement it using timers, it would be pretty simple to convert the Rules DSL to Python. They’re is also a submission to the Helper libraries that does almost exactly this with a looping timer, only it’s counting down how much time is left in a timer and you want to count up. But you should be able to use it as a reference. Initial submission of a Countdown Timer implementation by rkoshak · Pull Request #237 · openhab-scripters/openhab-helper-libraries · GitHub IIRC, it’s based on rossko57’s DP.

A Timer is a must in Rules DSL because on the thread pool issue but it’s ok to block a rule in scripted automation.

@rkrisi

Just do it how the usual Rules DSL pattern goes?

You can always use the same approach as you would in rules DSL. Nothing prevents that. It’s just that with python you have more options.