Cannot get template sensor data in statictics graph card

Configuration Frontend
1

I’m pretty new to HA, and need a bit of help …
I am trying to create a template sensor that derives its value from an other sensor, and display the result in a statistics graph card on my dashboard.

To do so, I added this to my configuration.yaml file:

template:
  - sensor:
      - name: "GraadDag_Today"
        unique_id: 'sensor.0a7476cc-d6c1-40ba-8ae1-606518c3497f'
        unit_of_measurement: "°C"
        state: >
          {% set MeanTempToday = states('sensor.buienradar_temperature') | float %}

          {{ 18-MeanTempToday }}

And added this statistics card to my dashboard (using code editor):

type: statistic
  entity: sensor.grdag_today
  period:
    calendar:
      period: day
stat_type: mean
name: GrDag Vandaag
unit: °C

The problem I encounter is as follows:

  • the statistics card shows up on my dashboard, however the sensor value is not shown (blank)
  • when I click on the card, the small window that pops up shows the correct graph (info tab)

Can anyone point out what I’m doing wrong here?

2

First of all, you are not using statistics, e.g. have a look below
There are also other options…
Second… you sensor.grdag_today is not equal to GraadDag_Today

Statistics - Home Assistant (home-assistant.io)