Multilevel Sensor CC: Wrong unit shown when a report with an unknown scale is used about certification-backlog

[marcelveldt]

we should be explicit in assigning the scale (0 for celsius and 1 for fahrenheit)

[AlCalzone]

This does not happen if the first received report has an unknown unit:

[raman325]

so I think the problem is that we generate the scales up front instead of responding to the device. So if there is a value update that changes the scale, we don't evaluate it. I don't understand how a 3 turned to fahrenheit unless we have some code that defaults back to it in some scenarios.

[MartinHjelmare]

From reading the entity helper code, the logic is like this that I can tell:

The entity is first added to the state machine and an entity registry entry is created for it. The unit that the entity has at that time will be set both in the state machine and in the entity registry. When the entity state is updated and the unit reported by the entity is None, the unit in the entity registry will be preferred. The entity registry entry is not updated unless the user overrides an attribute or if an integration makes an explicit update to the entity registry, eg during a migration, or if the entity is removed and added again. The entity registry is persistent between restarts.

Example 1:

• entity 1 is added with unit None: -> no unit is shown
• entity 1 updates unit to C: -> unit C is shown
• entity 1 updates unit to None: -> no unit is shown

Example 2:

• entity 2 is added with unit C: -> unit C is shown
• entity 2 updates unit to None: -> unit C is still shown
• entity 2 updates unit to F: -> unit F is shown
• entity 2 updates unit to None: -> unit C is shown again

Moving back to the Z-Wave integration specifics: Scale 2 is not in the temperature scales (0 or 1), of the enum, so the library will raise UnknownValueData and the temperature unit will be reported as None. See the example above what affect that could have on the entity state in different cases.

[MartinHjelmare]

Closed by mistake.

[MartinHjelmare]

Thinking about if we should change anything in the integration: Why should we consider an unknown scale to be accurate after we have had a report of a known scale from a device? Are there sensible use cases for this?

[AlCalzone]

Passing certification 🤷🏻‍♂️
Other than that I can't think of anything.