Creating a data template light

Configuration
1

Hi All,

I want to use an if then else statement to set the brightness for my light. I’m a bit in a lost . I’ve got the following statement tested succesfully in my developer tools >> templates

data_template: >
{% if now().hour < 12 %} 100
{% elif now().hour > 5 %} 50
{% else %}200
{% endif %}

What is the next step. I had a look at several youtube tutorials and they seem to talk about creating Sensor. Do I need to add this to my confiuration.yaml, so i can do a service call in my automation. Bit stuck here :slight_smile:

2

Does your light already exist in HA? If so, you need an automation, something like:

alias: Light brightness control
id: bec3fdde-f252-4ce2-b328-31a9e2bf8598
trigger:
  - platform: time_pattern
    minutes: "0"
action:
  - service: light.turn_on
    target:
      entity_id: light.your_light
    data:
      brightness: >
        {% if now().hour < 12 %} 100
        {% elif now().hour > 5 %} 50
        {% else %} 200
        {% endif %}
3

Also, you conditional logic looks flawed.

      brightness: >
        {% if now().hour < 12 %} 100
        {% elif now().hour > 5 %} 50
        {% else %} 200
        {% endif %}

The first if statement will always fire if the hour is less than 12.
However, this means the second statement actually is working like this:-

if hour>=12 … not >5, because the second elif will only trigger if the first if does not.

This does not appear to be what you are intending.

4

Agreed: this gives 100 up to 12, then 50 — never 200:

{% for h in range(24)|list %}
{{ h }}: {% if h < 12 %}100{% elif h > 5 %} 50{% else %}200{% endif -%}
{% endfor %}
5

Thnx for the feedback. I’ve adjusted my code in YAML as below.

alias: New Automation
description: Testing
trigger:
  - platform: time_pattern
    minutes: "0"
condition: []
action:
  - service: light.turn_on
    target:
      entity_id: light.werkkamer_plafondlamp_light
    data:
      brightness: >
        {% if now().hour > 12 %} 100 {% elif now().hour < 12 %} 50 {% else %}
        100 {% endif %}
mode: single

The weird thing is, that when I set my brightness to 100 and execute the above automatin, it sets it to 20. Any thoughts on this?

Step details give the below, which seems correct:

Executed: March 2, 2023 at 10:57:26

Result:
params:
  domain: light
  service: turn_on
  service_data:
    brightness: 50
    entity_id:
      - light.werkkamer_plafondlamp_light
  target:
    entity_id:
      - light.werkkamer_plafondlamp_light
running_script: false
limit: 10
6

Feels like you’re guessing at the template code without fully understanding what’s going on. Your latest attempt is equivalent to:

brightness: "{{ 50 if now().hour < 12 else 100 }}"

I assume you’re aware that the brightness ranges from 0 to 255 (ref)? Is it possible you’re setting it to 50 (out of 255) and reading it back as 20% elsewhere?

7

I think the confusion comes when you use the UI, you can express brightness as either a percentage or a 0-255 value.

If you want to use brightness as a percentage then use:

      - service: light.turn_on
        data:
          brightness_pct: 100

Also, your logic is still flawed This:

    data:
      brightness: >
        {% if now().hour > 12 %} 100 {% elif now().hour < 12 %} 50 {% else %}
        100 {% endif %}

Translates as the following:

13-23 hour, then brightness is 100
0-11 hour, then brightness is 50
12 hour, then brightness 100

Which again, is not what I think you are intending, or if it is, its slightly strange way of doing it, because it ultimately then becomes:

12-23 hour, then brightness is 100
0-11 hour, then brightness is 50

Which is probably what you ARE intending.