What is the best option for saving a rolling 24 hour temperature?

Hellis81 · April 3, 2020, 7:53am

I tried last night to create a dynamic attribute name with the temperature as the value but it didn’t work.
Then I found a post here saying it can’t be done without python

So how can I save 24 hours of weather temperature?
I need to have this data easily accessible since I want to output it on a MAX7219 8 bit display, something like temperature now and temperature say 5 hours ago.
As far as I have managed to google it’s not easily accessible in the history database, so that is why I thought I could just save it in an entity.
Since this doesn’t work:

customizer.set_attribute
  entity_id: input_text.text1
  attribute: now().hour
  value: 5

I assume I need some if, elseif to set the attribute name (?), but is that possible?
Can I break it up something like this?

customizer.set_attribute
  entity_id: input_text.text1
  if(now().hour == 0) attribute: "0";
  if(now().hour == 1) attribute: "1";
  ....
  ....
  value: 5

My hope is that it will work in an automation that runs every hour.

petro · April 3, 2020, 10:54am

use statistics sensor.

sensor:
  - platform: statistics
    entity_id: sensor.weather
    sample_size: 3600
    max_age:
      hours: 24

Add a really large sample size if you don’t know how many times the sensor updates in a day. It will cut off at max_age.

The state of that sensor is the ‘mean’, but the sensor itself has more attributes where you can get other stats out.

Chiny · April 3, 2020, 12:31pm

I’m using statistics (for electricity use tracking) and despite much fiddling, and reading documents, somehow I’ve managed to miss how I can get other stats out. A pointer would be appreciated.

petro · April 3, 2020, 12:32pm

they are attributes of the main sensor. Just take a look at the created sensor in the developer tools / states page. You’ll see that it has 10-15 attributes.

AhmadK · April 3, 2020, 12:50pm

2nd sentence of the official docs

Hellis81 · April 3, 2020, 2:14pm

I copy pasted this and only change the sample/sampling typo.
But the entity does not show up after a reboot.

Wait rebooting again, noticed the recorder: was missing

After reboot with recorder and sensor, nothing.
No sensor.weather

Chiny · April 3, 2020, 3:21pm

@petro @AhmadK Thanks guys. The magic (missed by me) word is attribute. Given that pointer, I took my existing entity_id and used value_template on it to find the mean. Not sure my solution is elegant but it works.

petro · April 3, 2020, 3:28pm

I’m guessing you made a binary_sensor? If you made it a sesnor, the mean is the main state.

Hellis81 · April 3, 2020, 3:37pm

No it’s not binary.
It’s listed below my pi_hole sensor and is:

- platform: statistics
    entity_id: sensor.weather
    sampling_size: 3600
    max_age:
      hours: 24

That is a copy paste of what my config says.

Hellis81 · April 3, 2020, 4:03pm

Wait… I think I understand now.
The entity_id is not the name of the sensor that is created. That is the sensor that I want to track?

In that case it should be something like:

sensor:
  - platform: statistics
    entity_id: {{ states.weather.smhi_home.attributes.temperature | float }} # weather.smhi_home.temperature
    sampling_size: 3600
    max_age:
      hours: 24

But it’s not a valid config.
I get:

Error loading /config/configuration.yaml: invalid key: “OrderedDict([(‘states.weather.smhi_home.attributes.temperature | float’, None)])”
in “/config/configuration.yaml”, line 250, column 0

petro · April 3, 2020, 4:13pm

I was talking to @Chiny with my last response.

What is the statre of sensor.smhi_home? If you are trying to use an attribute as the source, you’ll have to make a template sensor for the attribute before feeding it to the statistics sensor.

Chiny · April 3, 2020, 4:22pm

Apologies to @Hellis81 for piggy-backing but we have similar issues.

@petro I made a sensor, especially for the mean, wrongly as it turns out, based on your comment that the mean is the main state, which I now see in Developer Tools/States. Still, my value_template workings will still be useful for adding max/min. Then I need to do some arithmetic, to get costs. Then sort max_age, sampling, icon…

This is the Home Assistant version of some Python scripts that I have had running for a few years. I’m a newbie to HA, so this is very much experimental, and enjoyable.

Hellis81 · April 3, 2020, 4:33pm

So stat is the weather and the attribute holds the temperature (what I want).

So your saying I need:

sensor:
  -platform: template
   sensors: 
       dummy:
           value_template: {{ states.weather.smhi_home.attributes.temperature | float }}

then get this sensor in my statistic sensor?

Alright!!
So how can I now get the value that is the 10th (0.5 hours between the updates and I want five hours old temperature)

AhmadK · April 3, 2020, 4:44pm

how can it work if a) your source entity is weather.hem (not weather.smhi_home that you use in the template) and b) your template is single-line so in must be enclosed in quotes?
did you check your config or reboot HA after making the changes?

also, I’m almost certain you don’t need that | float as the result will be converted to a string anyway, you just need to make sure the result is always a string that represents a float, i.e nothing like unknown.

Hellis81 · April 3, 2020, 4:48pm

a) I don’t think it matters.
See this config:

sensor:
  - platform: template
    sensors:
      dummy:
        friendly_name: "DummyTemperature"
        unit_of_measurement: '°C'
        value_template: "{{ states.weather.smhi_home.attributes.temperature | float }}" 
      #value_template: "{{ states.weather.hem.attributes.temperature | float }}"  probably work too!
        
  - platform: statistics
    entity_id: sensor.dummy
    sampling_size: 3600
    max_age:
      hours: 24

Yes I rebooted after I added the above and it worked.

AhmadK · April 3, 2020, 4:56pm

well, now you have quotes around your template but still, is your entity weather.smhi_home? if yes, what’s this?

Hellis81 · April 3, 2020, 4:58pm

That is a incorrect screenshot. Sorry about that…

AhmadK · April 3, 2020, 5:14pm

petro · April 3, 2020, 5:50pm

Yes, that’s what I meant. You can add some safety so that you don’t get boot up errors by doing this:

sensor:
  - platform: template
    sensors:
      dummy:
        friendly_name: "DummyTemperature"
        unit_of_measurement: '°C'
        value_template: "{{ state_attr('weather.smhi_home','temperature') }}"
        
  - platform: statistics
    entity_id: sensor.dummy
    sampling_size: 3600
    max_age:
      hours: 24

You don’t need the float because i’ts already a float and you’re sending it out at that point. The unit of measurement determines that it’s a ‘number’ for your graphs.

Hellis81 · April 3, 2020, 6:19pm

Ok!

But is there any way you get the values from this graph? By code I mean?
I want to pass this value(s) to a 7 segment display.