KNX - relative dimming for lights blueprint

knx-relative-dimming-for-lights.yaml

blueprint:
  name: KNX - relative dimming for lights
  description: Control Home Assistant light entities from KNX switching and relative dimming (DPT 3.007) telegrams.
  homeassistant:
    # `knx.telegram` trigger and `enabled` templates require Home Assistant 2024.6.0
    min_version: "2024.6.0"
  domain: automation
  input:
    target_lights:
      name: Light
      description: The lights that shall be controled.
      selector:
        target:
          entity:
            domain: light
    switch_address:
      name: Switch group address
      description: >
        Group address for switching the lights on and off. DPT 1
        Example: '1/2/3'
      default: null
    dimm_address:
      name: Relative dimming address
      description: >
        Group address for dimming the lights. DPT 3.007
        Example: '1/2/4'
      default: null
    dimm_time:
      name: Dimm time
      description: Time dimming from 0 to 100% shall take.
      selector:
        number:
          min: 1
          max: 20
          step: 0.1
          unit_of_measurement: seconds
          mode: slider
      default: 4
    dimm_steps:
      name: Dimm steps
      description: Steps used to dimm from 0 to 100%.
      selector:
        number:
          min: 2
          max: 100
          step: 1
          unit_of_measurement: steps
          mode: slider
      default: 20

# no matched condition stops repeat sequence to stop dimming (dimm 0)
mode: restart
max_exceeded: silent

variables:
  _dimm_time: !input dimm_time
  _dimm_steps: !input dimm_steps
  dimm_time: "{{ _dimm_time|float }}"
  dimm_steps: "{{ _dimm_steps|int }}"
  dimm_step: "{{ (255 / dimm_steps) | round(0, 'ceil') }}"
  dimm_delay: "{{ dimm_time * 1000 / dimm_steps }}"

trigger_variables:
  _switch_address: !input switch_address
  _dimm_address: !input dimm_address

trigger:
  - platform: knx.telegram
    destination: !input switch_address
    group_value_read: false
    group_value_response: false
    id: "switch"
    enabled: "{{ _switch_address != None }}"
  - platform: knx.telegram
    destination: !input dimm_address
    group_value_read: false
    group_value_response: false
    id: "dimm"
    enabled: "{{ _dimm_address != None }}"

action:
  - choose:
    # TURN ON
    - conditions:
        condition: and
        conditions:
          - condition: trigger
            id: "switch"
          - "{{ trigger.payload == 1 }}"
      sequence:
        - service: light.turn_on
          target: !input target_lights
    # TURN OFF
    - conditions:
        condition: and
        conditions:
          - condition: trigger
            id: "switch"
          - "{{ trigger.payload == 0 }}"
      sequence:
        - service: light.turn_off
          target: !input target_lights
    # DIMM UP
    - conditions:
        condition: and
        conditions:
          - condition: trigger
            id: "dimm"
          - "{{ 9 <= trigger.payload <= 15 }}"
      sequence:
        - repeat:
            count: '{{ dimm_steps }}'
            sequence:
              - service: light.turn_on
                target: !input target_lights
                data:
                  brightness_step: '{{ dimm_step }}'
              - delay:
                  milliseconds: '{{ dimm_delay }}'
    # DIMM DOWN
    - conditions:
        condition: and
        conditions:
          - condition: trigger
            id: "dimm"
          - "{{ 1 <= trigger.payload <= 7 }}"
      sequence:
        - repeat:
            count: '{{ dimm_steps }}'
            sequence:
              - service: light.turn_on
                target: !input target_lights
                data:
                  brightness_step: '{{ -dimm_step }}'
              - delay:
                  milliseconds: '{{ dimm_delay }}'

Depends on the actuator, I guess. The ones I know support DPT 3 color temp dimming, just like brightness.
And HA supports Kelvin too, so no need to deal with Mireds afaic.

Yeah, kelvin should be fine for Phillips Finance white

Updated to use knx.telegram trigger released in HA 2024.6

@farmio This works absolutely perfectly, I can‘t thank you enough. Implementing this myself would have been hell.

I have a question though: how can I alter this to mimic the KNX behaviour „don‘t turn off through relative dimming“? I.e. when I dim down I want the light to stay at the lowest brightness instead of turning off. The Home Assistant UI also behaves this way.

@bob-lobster I think it depends on the target entity. Not every one turns off on brightness = 0 - or is configurable (like most KNX actuators).
If you can't set it in the target integration, try modifying line 134 to set an absolute brightness based on max(current_brightness - dimm_step, 1) or something like that.

Thanks I changed it to

brightness: “max(state_attr('light.bed', 'brightness')-dimm_step, 2)“

With absolute brightness 1 they would be at 1 % and on in HA but the bulbs were off.

They are Hue bulbs via Skyconnect actually but I couldn‘t figure out how to change the behaviour there.

Hi,

thank you for this blueprint code.
It works great for me. I am using an MDT KNX Wall Switch with an HUE ceiling light.
I could set those paramters for my claims.

Is it possible to add one more slider for an inital value?

Right now i switch on and off on a plus and a minus button with a short tap and same with dimming the light, but with long taps.
I would like to switch on the light everytime to 100% by Default. Right now it turns on by default with the last value

Cheers
Christian

@CyberChris79 Hi 👋! IMO turn on value should be handled by the actuator - most provide configurations for that.

The intention of this blueprint is to provide a reference for the usage of Knx actions and triggers - for other blueprint creators. So I don't plan to add any features to it.
Feel free to fork it and modify to your needs.
Or have a look for existing forks - maybe the thing you are looking was already done by someone else.