Map battery level to %

[elik745i (Elik)]

Yes, that is good idea, for now I have used JS transformation on the title to show percentage, that is fine and when I go to details I have generated another binding with voltage showings. That is perfect for now.
Thanks for support bud!

[chercheur (Robert)]

Hello,

I’m also turning around…
I want to closely monitor my thermal cranes (thermostats) batteries.
They range from 3v (new) to 2.2v (empty…would require an alarm).

So my range goes from 2.2 to 3…and I would like to display it at the levels:

• 2.2v = empty
• 2.4v
• 2.6v
• 2.8v
• 3.0v= full

As a perfect newbie I really don’t understand all the proposals about transform/proxy/others…
Would anyone have a real life example to share ?

Tx!

[rossko57]

What actual state do your Items take up? This influences paths available to you.

[chercheur (Robert)]

The battery level is fetched per 0.1 volt.

[rossko57]

What actual state do your Items take up?
Perhaps show us an events.log entry.

[mstormi (Markus Storm)]

@rossko57

Maybe you should adjust your icons to fit your displayed voltage.

Or use a 2nd item with range 0-100, standard icons and a rule to trigger upon changes of your original value and to convert it instead of using a transformation. That rule can also issue a warning right away.

[chercheur (Robert)]

Here you go:

2020-11-01 16:41:46.519 [vent.ItemStateChangedEvent] - VanneSalleDeJeu_4_BatteryState changed from NULL to 2.80 V

2020-11-01 17:24:32.551 [vent.ItemStateChangedEvent] - VanneCouloir1erTage_4_BatteryState changed from NULL to 2.30 V

[rossko57]

Okay, your Items are quantity types - they have units. You need to know that for your rules and transformations.

The constraint is that dynamic icons only work for 0-100 and only in integer steps, i.e. you get the same icon for 2.1 as 2.9.
So you will have to use a dummy Item with scaled value, as @mstormi suggests.

Optionally, you can add a transformation to un-scale the dummy state for a display text.

[chercheur (Robert)]

Tx.

Could you guide me in setting up that “dummy item with scaled value” ?

[mstormi (Markus Storm)]

@chercheur

Could you guide me in setting up that “dummy item with scaled value” ?

see

Design Pattern: Unbound Item (aka Virtual Item)

Problem Statement Sometimes one needs to create a flag, control, switch, or some other control that is not bound to a device or channel. For example, a Switch to override presence detection. Concept Create an Item that does not have a binding configuration. Simple Example Switch VirtualItem "label" <icon> (groups) // No binding config See the Sensor Aggregation Design Pattern for a more complicated example. The Virtual Item is Override_Presence in that example. Advantages and Limitations V…

[chercheur (Robert)]

Not as evident as you think it is

I keepthinking…
in my sitemap: Text item=ThermostatSalon_2_BatteryState icon=“batterie”

Where ThermostatSalon_2_BatteryState givesthe value used by the dynamic icon “batterie”.

I’m an absolute noob when it comes to put my ideas in a “script” … I keep searching

[rossko57]

What we’re saying is that Item is no use in your sitemap. You’ve decided you want icons to work a certain way, and that cannot happen using the values that Item takes.

So you need to make another Item that can have a range of values that you can use with icons, and you put that Item on your sitemap instead.

A rule can listen for changes in your original Item, and do some maths on the value and place the scales value into your new dummy Item.