a HomeAssistant automation for using an MQTT smart knob for controlling the volume of a media_player

mqttknob.yaml

alias: "Knob: Volume Up/Down"
description: "Knob: Volume Up/Down"
triggers:
  - domain: mqtt
    device_id: 96d04892651a90bd5c81cd7211453052
    type: action
    subtype: brightness_step_up
    trigger: device
  - domain: mqtt
    device_id: 96d04892651a90bd5c81cd7211453052
    type: action
    subtype: brightness_step_down
    trigger: device
conditions: []
actions:
  - variables:
      action: "{{ trigger.payload }}"
      media: media_player.tv_arc
      volume_level: "{{ state_attr(media,'volume_level')  | float | round(2) }}"
      action_step_size: "{{ states.sensor.smart_knob_action_step_size.state_with_unit }}"
  - choose:
      - conditions:
          - condition: template
            value_template: "{{ action == \"brightness_step_down\" }}"
        sequence:
          - data_template:
              entity_id: media
              # the /5 here smooths out the volume steps so they're not so jarring
              volume_level: >-
                {% set sub = ((state_attr(media,'volume_level') - (action_step_size | float / 5 / 100 ))) | round(2) %}
                {{ ([0, sub, 1]|sort)[1] }}
            action: media_player.volume_set
      - conditions:
          - condition: template
            value_template: "{{ action == \"brightness_step_up\" }}"
        sequence:
          - data_template:
              entity_id: media
              # the /5 here smooths out the volume steps so they're not so jarring
              volume_level: >-
                {% set sum = ((state_attr(media,'volume_level') + (action_step_size | float / 5 / 100 ))) | round(2) %}
                {{ ([0, sum, 1]|sort)[1] }}
            action: media_player.volume_set
mode: queued
max: 10