How to do sensor math the right way

[kuna]

I have some ESPhome devices which reads data via RS from some hardware. Of course this sensors getting unavailible sometimes, during updates etc.

If i look at the graph of this sensors it looks correct.

Now i need to summarize three sensors, in this case they are in one ESPhome device, but i want a solution to do the math outside of ESPhome, if i want to summarize two sensors from different devices.

So i have do a template like this:

template:
  - sensor:
    - name: 'Moc czynna przyłącze'
      unit_of_measurement: 'kW'
      device_class: power
      state_class: measurement
      state: >
        {% set moc_a = states('sensor.mew_przylacze_a_moc_czynna') | float %}
        {% set moc_b = states('sensor.mew_przylacze_b_moc_czynna') | float %}
        {% set moc_h7 = states('sensor.mew_przylacze_h7_moc_czynna') | float %}
        {% if ((moc_a + moc_b + moc_h7) > -1000) %}
        {{ ( moc_a + moc_b + moc_h7) | round(1) }}
        {% endif %}

It works, but if the sensors are not availible this template returns 0, i dont want “0”, because it create a negative spike in the graph and also shows wrong value.

Can You help me out?

[tom_l]

Updating Templates with the new default values in 2021.10.x

I keep seeing the same question about the new default argument for the templating. This post will cover all possible ways to define default. All the methods that were changed: acos as_timestamp asin atan atan2 cos float log round sin sqrt strptime tan timestamp_custom timestamp_local timestamp_utc Each of them have the exact same default functionality but a different number of arguments. There are multiple ways to use these functions, and this is where all the confusion lies. Understandi…

[petro]

add an availability template to that and you shouldn’t have to touch your template.

      availability: >
        {{ expand('sensor.mew_przylacze_a_moc_czynna', 'sensor.mew_przylacze_b_moc_czynna', 'sensor.mew_przylacze_h7_moc_czynna') | rejectattr('state','is_number') | list | count == 0 }}

[kuna]

Thx, this solved the issue.
So now it looks:

template:
  - sensor:
    - name: 'Moc czynna przyłącze'
      unit_of_measurement: 'kW'
      device_class: power
      state_class: measurement
      state: >
        {% set moc_a = states('sensor.mew_przylacze_a_moc_czynna') | float %}
        {% set moc_b = states('sensor.mew_przylacze_b_moc_czynna') | float %}
        {% set moc_h7 = states('sensor.mew_przylacze_h7_moc_czynna') | float %}
        {{ ( moc_a + moc_b + moc_h7) | round(1) }}
      availability: >
        {{ expand('sensor.mew_przylacze_a_moc_czynna', 'sensor.mew_przylacze_b_moc_czynna', 'sensor.mew_przylacze_h7_moc_czynna') | rejectattr('state','is_number') | list | count == 0 }}

Will it render unavailable if any of the sensors failes, or need all sensors to fail?

[petro]

yes, any sensor that fails will make this unavailable and the calc will not appear in your energy

[petro]

That can be changed too if needed