I have exposed a HA entity onto the KNX bus, a SwitchBot outdoor thermo-hygrometer. The value, however, is not translated, something is wrong with the datapoint type (DPT):
When adding the entity through the GUI, the GUI reports the same:
The YAML looks exactly as described in the HA documentation:
expose:
- type: temperature
entity_id: sensor.indoor_outdoor_meter_5b1e_temperatuur
address: "0/3/1"
Do I need to set a DPT on the group address in ETS?
Hi 
!
The value is translated just fine, but the group monitor doesn't know about it... see below
You either set it up in UI config panel or in YAML. If you do both, you'll send the value twice on each state change.
Yes, if you want the group monitor to display a decoded value.
An expose type is not a source for the group monitor - it's only used for encoding the value.
The "DPT is incompatible..." warning comes from the selected DPT not being the same as the GAs DPT in the used project. It's only a warning though - setting a GA (or having a project at all) isn't needed for the expose work.
Thanks @farmio. I only have it set up in the YAML, after a few tries through the UI first. All messages you see in the monitor screenshot are unique, no dupes.
I will check in the ETS, thanks.
I have set the DPT to 9.001 (temperature) in ETS and imported it into HA again, but the reading still shows the raw hex value. The group address is empty in ETS.
I think empty group addresses are ignored. Not 100% sure right now though. Try assigning it at least to the interface you are using for HA connection (see Integration docs).
Well... I'm not sure what happened, but all of a sudden the GA started printing the decoded value on the bus, a few minutes after my last upload. So it does seem like even with the GA being empty, as long as the DPT is set correctly it is registering.
Thanks for your help once more @farmio.
Uploading / updating project data doesn't change historic data. Only telegrams seen after the update will be shown decoded.