How can I get history from sensor templates

ESPHome
1

Hello All,

I hava four humidity sensors and want to create an additional one with the mean of all four. For this, I have created a template. I properly get the value, but cannot get the history. I have searched but cannot get a precise answer. What am I missing ?

  - platform: template
    name: "TCm Humidity"
    lambda: 'return ((id(B0H).state+id(B1H).state+id(B2H).state+id(B3H).state)/4.0);'
    update_interval: 5s
    id: BHm

All four Humidity sensors are created with the following code ( for sensor 0)

sensor:
  - platform: bme280
    i2c_id: multiplex0channel0
    address: 0x76
    humidity:
      name: "TC0 Humidity"
      accuracy_decimals: 2
      id: B0H
    update_interval: 5s

ESPHome 2023.12.5

2

I found the problem. The sensor needs additional information for the history to work. It not clear from the documentation.

I added

    unit_of_measurement: "%"
    device_class: "humidity"
    state_class: "measurement"

and it works. Did not try yet to see which is mandatory

3

where did you find that information? I don’t recall seeing it in the Docs, but it’s interesting and good to know.

4

I did not really see it in the doc.
It was some guess from the analysis of the output and small pieces of dissiminated information in various posts.

5

hhmm. Well, It’s good to know either way I suppose.