Adjusting light brightness/temperature

Configuration
1

I am new to HA template, I want to set an automation to increase/decrease light brightness and temperature on trigger. However, when I test the below action in development/service page, the code is not working.
I can only update the light by put a static value to the brightness/color_temp attribute, but not a template. Any advise on how to inc/dec light brightness/temperature?

I am using HA version 2022.5. Thanks!

service: light.turn_on
data_template:
  transition: 1
# the templates statement below is not working
  brightness: {{ state_attr('light.livingroom_tv_lightbulbs','brightness')|int + 10 }}
  color_temp: {{ state_attr('light.livingroom_tv_lightbulbs','color_temp')|int + 10 }}
# replace to below code will work
#  brightness: 50
#  color_temp: 100
target:
  entity_id: light.livingroom_tv_lightbulbs
2

You no longer need to use data_template, just data will do.

You need to quote single line templates.

service: light.turn_on
target:
  entity_id: light.livingroom_tv_lightbulbs
data:
  transition: 1
  brightness: "{{ state_attr('light.livingroom_tv_lightbulbs','brightness')|int(128) + 10 }}"
  color_temp: "{{ state_attr('light.livingroom_tv_lightbulbs','color_temp')|int(6000) + 10 }}"

You should also supply default values for your |int filters in case the entities return a non numeric value. In this case I have chosen 50% brightness (128/255) and cool white for the color temp. Feel free to change them to whatever you want.

You also need to guard against the brightness value exceeding 255, e.g.

 {{ [state_attr('light.livingroom_tv_lightbulbs','brightness')|int(128) + 10, 255]|min }}

You should also do this for your color temp, but I don’t know what the maximum for your light is.

3

Thanks for your kind description about the default value and min operation. It is very useful for me to enhance my scripts.
However, I found the templates for lighting control is still not working, as the service call on template attributes will not do anything.
I can show the template values in Development page as attached, But whenever I put it into data part of the light_on service call, it will do nothing. Seems the light-on service call just ignored the template attributes.

ha_lightOn_tempValues
ha_lightOn_tempValues906×299 55 KB

4

Please post your action, now that you have edited it.

5

Oh, I’ve missed double quote for the template. It works after I double quote for the template part in the script.
Thank you again for kind help!

6

No problem. Yeah if you don’t use different types of quotes you end up with this:

brightness: '{{ state_attr('

Also 250 seems a very low default colour temp. Are you sure your light supports this?

7

Yup, I found the light (Aqara light bulb) only support color temperate range from 153 to 370. So I use 250 as default value.

8

Oh right. I keep forgetting that color_temp is in mireds. It’s the kelvin attribute that is 2700° to 6000°.