KNX Dimming (DPT 3.007) Not Working Properly

Configuration
1

Hi there,

Problem:
I have been trying to get KNX dimming (DPT 3.007, relative dimming) to work in Home Assistant, but I haven’t been successful. Neither the “KNX - Light Entities Control” Blueprint nor the built-in KNX integration seem to work correctly for my setup.

Current Setup:

• KNX Light Configuration:

knx:

light:

  • name: “KNX Light”

address: “2/0/17” # Switch address

state_address: “2/0/21” # Status address (on/off feedback)

brightness_address: “2/0/18” # Relative dimming (DPT 3.007)

brightness_state_address: “2/0/20” # Brightness feedback

• Tested with Blueprint (kalhimeo’s KNX light control), but the brightness values remain between 0-255 instead of 0-15.

• Adjusting brightness_step in the Blueprint didn’t fix the issue.

• Home Assistant’s UI slider does not control the brightness correctly. When moving the slider, nothing happens.

What Works:

• Manually sending dimming commands via Developer Tools → Actions works fine:

service: knx.send

data:

address: “2/0/18”

payload: 15

• Values between 0 and 15 dim correctly.

• Negative values (e.g., -7) dim down.

What I Need Help With:

  1. How can I properly scale the brightness values (0-255) to 0-15 inside the Blueprint or Home Assistant’s KNX integration?

  2. Is there a way to make the Home Assistant UI slider send the correct range (0-15) instead of 0-255?

Any help would be greatly appreciated! :rocket:

Thanks Marc

2

Hi :wave:!

This is invalid - it needs to point to a DPT 5 address. See the documentation KNX - Home Assistant

1 Like
3

Hi,

I first had to learn the hard way that my KNX project didn’t have any feedback objects or status group addresses configured. Also, the 5.001 absolute dimming function wasn’t set up.

I completely reworked everything and then configured dimming in HA using the built-in tools with 5.001 for absolute dimming and 3.007 for status feedback. It works perfectly now! I didn’t even need to use the blueprint.

Thanks so much for the support here! :+1:

4

That’s not correct - brightness_state_address expects DPT 5 too. See the documentation https://www.home-assistant.io/integrations/knx/#brightness_state_address every key has the expected DPT listed there.

DPT 3 is not used anywhere in a knx light entity configuration.

5

grafik
grafik1990×119 14.7 KB

sorry my hardware use it.

6

It’s fine to use it with for knx push buttons - it’s just not for a HA light entity. You should connect GO 35 to brightness_state_address.

BTW: It’s awkward to have multiple GAs connected to a status object (34 and 35). This object only sends data, it ignores incoming, so the second GA does nothing.

1 Like