ESP custom component how to get entity values from home assistant

ESPHome
1

I carried out successfully a custom component in C++ (arduino like) on a ESP8266 follwoing the amazing tutorial here Custom Sensor Component — ESPHome
Mainly I did that to move a bit of “smartness” to the ESP in order to control in realtime some critical parameters which must safe independently from a latency or momentary wifi loss connection)
It works fine!
However I would pass to ESP8266 code (c++) dinamically some parameters from home-assistent entity (or helpers) instead of a hard-coding parametrization.
How to do that from the C-code of the custom component? How to access to the HomeAsssistent entities ?

2

I think a homesssistant sensor with an id

sensor:
  - platform: homeassistant
    name: "Parameter from HA"
    entity_id: some.ha_entity
    id: param

Then in your lambda / c++ code

id(param).state
1 Like
3

Yeah!!!
Thanks a lot nickrout !!

4

So when I add id to a sensor in HA and use id(param).state in esphome it will use the entity value of the sensor?

Now I have this:

  - platform: homeassistant
    name: "Daytime"
    entity_id: input_boolean.scene_daytime
    id: "daytime"
    on_value:
      - if:
          condition:
            lambda: 'return id(daytime).state == "on";'
          then:
            - light.turn_on: # RED
                id: neopixel
                brightness: 100%
                red: 100%
                green: 0%
                blue: 0%

But if what I ask is right I can change this and remove the whole platform part and use only the

id(param).state

in the esphome automations

5

You don’t add the id in your HA code, you add it in your esphome code. You still need the platform: homeassistant to get the value into the esp, then to reference that value in a lambda you use id(param).state

I hope that is clearer now.

6

Yes. The way how I already do :slight_smile:

7

Hello thanks for your suggestions, I have another related issue:

I would like to pass several H.A. entities value to the class of my custom component library
let’say the entity is given by a helper
her my C code

---C code---
my personal .h file 

class cESPCustomDevice : public PollingComponent, public Sensor { 
  public:
    float param1, param2, param3;
    cESPCustomDevice(float p1, float p2, float p3) : PollingComponent(100) { //costructor
      param1 = p1;
      param2 = p2;
      param3 = p3;
    };
	Sensor *MySensor = new Sensor();
....
	MySensor->publish_state(val);
}

so once defined in H.A. a helper “input_number.param1”
I have this YAML

---YAML code---

- platform: homeassistant
  name: "Param_1"
  entity_id: input_number.param1
  id: par1
	
- ...Param_2
- ...Param_3

- platform: custom
  lambda: |-
    auto esp_customcomponent = new cESPCustomDevice(id(par1).state, ... , ...);
    App.register_component(esp_customcomponent);
    return {esp_customcomponent->MySensor};

it works but my question is: there is a simpler solutions to pass the entity value “input_number.param1” in the YAML file instead to define a local entity “par1” and passing it ?

I tried with

- platform: custom
  lambda: |-
    auto esp_customcomponent = new cESPCustomDevice(id(input_number.param1).state, ... , ...);

and

    auto esp_customcomponent = new cESPCustomDevice(id(input_number.param1).currentstate, ... , ...);

But it doesn’t work. Any suggestions?
Thanks a lot.

8

I have managed to transfer data by using the constructor and geting my instantiated component, then updating it’s value using homeassistant sensor on_value …
It’s not my idea I just found it.