Is Ha with ESPhome a 1-way route

ESPHome
1

in short … no values seen on a nextion display connected to an esp8266 (brain too short I bet)

situation:
esp1 with a bme280

sensor:
  - platform: bme280
    temperature:
      name: esp1_temperature

results in having an entity with the entity_id

sensor.esp1_temperature

inside HA which could be used anywhere, lovelace, …

then I have a second esp8266 connected to a nextion display, named esp2 containing

sensor:
  - platform: homeassistant # outside temp
    id: esp1_temperature
    entity_id: sensor.esp1_temperature

display:
  - platform: nextion
[ ... ]
  it.set_component_text_printf("objname","%2.1f",id(esp1_temperature).state);

and the result remains ‘nan’.

if using

it.set.component_text("objname","test");

Since so I expect the esp2 with the display set up correct. No TX/RX issue or such like.
Enabling loggging on that esp might show the misery since all the entity_ids are shown providing a value of ‘’. eg. nothing. REsulting in ‘nan’ on the display itself.
Is esphome a 1-way-route, means doe it only allow to feed HA with entites while not being able to read their values? Got no clue since all examples seen in here seem to work.
And the ESPhome help doesn’t tell any differnt how it should work.

2

Yes you can read their value. See this example. https://esphome.io/cookbook/display_time_temp_oled.html

3

Seen this, and it also lacks to mention the 1 and only essential stop one should forget about.

If one flashes an ESP using the ESPhome from within HA everything smoothly works hand in hand.

What’s rarely mentioned is: don’t forget you need to integrate that newly flashed ESP into HA
And as long as one forgets about this simple thingy, the ESP with the display will never ever get any values from the entity_id HA is aware of.

A nice bloke mentioned this in another article I stumbled across last night.

Anyway issue solved …

4

Yes that is certainly correct that you have to integrate the esp into HA.