Help with Irrigation factor for rain and temperature

[RouxStrauss]

Hey, sorry @patfelst. Hope this is the right way to do it.
I implemented the rain forecast and past history factor so lower the irrigation time. My factor is on 0.974 atm. I however live in a area where the temperature goes up to 45°C and would like to have the system see that and then increase the spraying time. I saw that you pointed out a bug about this. I would like to know if it is possible to have the temperature and the forecast setup on the same script and how to set it up.
Thanks!

[patfelst]

Yes I believe it is. I’ll answer tomorrow.

[RouxStrauss]

@petergridge could you maybe assist? Also how does the frequency for temperature work exactly? How do I configure the script to match my needs?

[patfelst]

So you need to learn how to use home assistant jinja templates. You can experiment in home assistant's template editor, you'll find it under developer tools.

Here's a complete example you can paste into the template editor. It's showing how you could use the temperature history (max temperature of each day) for the last 4 days and also today (day0max). It outputs a single floating point number which is the adjustment factor. You can use any function you can dream up here. I just asked chatgpt to write a function and this is what it came up with.

{% set day0max = 35 %}
{% set day1max = 30 %}
{% set day2max = 26 %}
{% set day3max = 25 %}
{% set day4max = 18 %}

{% set temp_base = 24 %}
{% set temp_slope = 0.04 %}

{% set weighted_temp = (
    day0max +
    (day1max * 0.5) +
    (day2max * 0.25) +
    (day3max * 0.12) +
    (day4max * 0.06)
) / (1 + 0.5 + 0.25 + 0.12 + 0.06) %}

{% set temp_factor = 1 + ((weighted_temp - temp_base) * temp_slope) %}

{# ===== IF/THEN CLAMP ===== #}
{% if temp_factor < 0 %}
  {% set clamped_factor = 0 %}
{% elif temp_factor > 2 %}
  {% set clamped_factor = 2 %}
{% else %}
  {% set clamped_factor = temp_factor %}
{% endif %}

{{ clamped_factor | float }}

You should see the result of 1.34 in the template editor.

The first five lines {{ set dayx... = xx }} are only needed in the template editor, they are simulating some daily maximum temperatures, or else you could replace them with the actual sensors from OWMH like this

{% set day0max = states('sensor.owmh_home_day0max') | float %}
{% set day1max = states('sensor.owmh_home_day1max') | float %}

etc

Once you're happy with the template, create a new sensor in OWMH, and paste it in, exept of course don't include the first 5 lines as they are internally generated by OWMH.

[petergridge]

@patfelst, a good explanation of using jinja template and template developer option.