Template to Store Last Tripped Sensor?

Configuration
1

Hello Community,

I’m looking to create a Sensor Template to store the last tripped sensor from a group of binary sensors. Does anyone know if this is possible and might give me some hints?

TIA

2

would be handy for my alarm hmmmm

3

Someone else had the same request in another thread. The issue they are facing is that, on startup, one of the binary_sensors doesn’t get initialized promptly so it takes some time before it ‘exists’. That presents a problem for the Template Sensor because, on startup, it promptly refers to a binary_sensor that doesn’t exist yet (which produces an error).

The alternative is to use an automation that is triggered by any one of several binary_sensors. Whichever sensor triggers the automation gets its friendly_name stored in an input_text.

If this solution (or the first one) interest you, head over to this thread:

4

Hi, I using this approach and with the variable component. This will do what you looking for if I understand what you are after (early monday morning…)

5

Here’s how I setup a template sensor:

- platform: template
  sensors:
    template_last_motion:
      friendly_name: 'Motion'
      icon_template: 'mdi:walk'
      entity_id:
        - binary_sensor.garage_motion
        - binary_sensor.motion_sensor_158d0003d57f46
        - binary_sensor.motion_sensor_158d0002f786a1
        - binary_sensor.motion_sensor_158d00047906a4
      value_template: >
        {% set allmotion = states | selectattr('entity_id', 'in', state_attr('group.motion', 'entity_id')) | list %}
        {% set open= allmotion | map(attribute='last_changed') | list |max %}
        {{allmotion |selectattr('last_changed','eq', open)|map(attribute='name')|list|join}} ({{allmotion |selectattr('last_changed','eq', open)|map(attribute='state')|list|join}}) on {{ as_timestamp(open) | timestamp_custom('%d/%m/%Y at %-Hh%M') }}

Entity_Id (4x) trigger a change of the sensor template. These 4 Sensors are in a group called group.motion.
You can test it out in the “Templates” Section of your HA:

Screenshot%20from%202019-07-15%2011-54-53
Screenshot%20from%202019-07-15%2011-54-531272×692 64.5 KB

6

Thanks to both of you. I’m actually trying to catch the last tripped binary_sensor and not all of them are motion sensors. Can your code be adapted by including all the sensors and changing the variable name allmotion to something like alltripped?

7

The example I provided isn’t tied to a specific type of binary_sensor. For that matter, neither is hiscorebob’s example. ‘allmotion’ is just a variable name within the template. The template is acting on all the entities it finds within a group called group.motion. That group can contain, and be named, anything you want. You’re free to create a group called group.my_group and have it contain only door and window binary_sensors. Then use that in the template. The choice is up to you.

8

Thank you so much! I’ll give it a try tonight.

Update: works like a charm! I went with the template from @hiscorebob as it was better suited to my needs, but thanks to @123 as well!

9

If you’re interested, here’s a streamlined version of hiscorebob’s Template Sensor.

For the binary_sensors you wish to monitor, enter them directly within the template’s sensors list. There’s no need to list them in entity_id: or to create a group containing them.

  - platform: template
    sensors:
      last_activated:
        friendly_name: 'Last Activated'
        value_template: >
          {% set sensors = [states.binary_sensor.front_door,
                            states.binary_sensor.rear_door, 
                            states.binary_sensor.garage_door] %}
          {% set time = sensors | map(attribute='last_changed') | max %}
          {% set sensor = (sensors | selectattr('last_changed','eq', time) | list)[0] %}
          {{sensor.name}} {{sensor.state}} {{sensor.last_changed.timestamp() | timestamp_custom('%b-%d %-H:%M')}}

The output looks like this:
Garage door off Jul-16 21:40
However, you can easily modify it to produce whatever you prefer.

Be advised that, upon startup, Home Assistant sets an entity’s last_changed value to the current date and time (i.e. the time when Home Assistant restarted). That means moments after startup all entities have the same last_changed value. In other words, this attribute’s value doesn’t survive a restart; it is reset after every restart.

3 Likes
10

This code works great. Except I just want to know the last ‘on’ state. How would I modify this code to fit my purpose?

11

Anyone has found a way to change the template sensor only on “on” state of the reference sensors?