How to use datetime from Home Assistant in ESPhome?

ESPHome
#1

Is it possible to use the datetime from a sensor in Home Assistant in ESPhome?
So I have a sensor in Home Assistant that has an attribute datetime with the value: '2022-09-24T11:00:00+00:00'
I then import this sensor in ESPhome in the following way:

text_sensor:
  - platform: homeassistant
    id: datetime
    entity_id: sensor.WeahterPredictions
    attribute: datetime

I then try to print this on my e-paper with lambda as such:

display:
  - platform: waveshare_epaper
    cs_pin: 22
    dc_pin: 23
    busy_pin: 32
    reset_pin: 21
    model: 7.50in-hd-b
    update_interval: 30sec
    reset_duration: 2ms
    rotation: 90°
    lambda: |-
      it.strftime(75, 518, id(tm24), color_white, TextAlign::TOP_CENTER, "%B", id(timedate).state);

This generates an error while compiling:

error: no matching function for call to 'esphome::display::DisplayBuffer::strftime(int, int, esphome::display::Font*&, esphome::Color&, esphome::display::TextAlign, const char [3], std::__cxx11::string&)'
       it.strftime(75, 518, id(tm24), color_white, TextAlign::TOP_CENTER, "%B", id(timedate1).state);
                                                                                            ^

I understand that somehow I am using the wrong format in for strftime. But I cannot figure out what format to use in order use the datetime from Home Assistant and show different aspects of that datetime in different formats throughout the dispaly, without having to make a sensor for each format. I am trying to limit the number of sensors as ram is limited for the esp32

Any help would be greatly appreciated.

#2

There may be multiple way of doing this, I half-a-beginnger but this is what I do for my nspanel >esphome

time:
  - platform: homeassistant
    id: homeassistant_time
    on_time:
      - seconds: 0
        minutes: /1
        then:
          - lambda: id(disp1).set_component_text_printf("Home.time", "%02i:%02i", id(homeassistant_time).now().hour, id(homeassistant_time).now().minute);
          - lambda: id(disp1).set_component_text_printf("Home.date", "%i-%02i-%02i", id(homeassistant_time).now().year, id(homeassistant_time).now().month, id(homeassistant_time).now().day_of_month);
    on_time_sync:
        then:
          - wait_until:
              switch.is_on: nextion_init
          - lambda: id(disp1).set_component_text_printf("Home.time", "%02i:%02i", id(homeassistant_time).now().hour, id(homeassistant_time).now().minute);
          - lambda: id(disp1).set_component_text_printf("Home.date", "%i-%02i-%02i", id(homeassistant_time).now().year, id(homeassistant_time).now().month, id(homeassistant_time).now().day_of_month);

‘home’ is my first /main page on the nextion

#3

Thanks @vingerha, but that is just taking the time from Home Assistant (the time function). I need the datetime that is provided by the weahter forecast to be put in several different formats around my e-paper display.

For example I would like the date (which is a date anywhere in the future) and the month of that date and the name of the day of that date, on different places on the display. How I do it now is create three different text_sensors with that information. I would like to use one text_sensor that gets the datetime and then through strftime extract the date, day and month.

I know how to to do that with the current time:

it.strftime(75, 518, id(tm24), color_white, TextAlign::TOP_CENTER, "%B", id(ha_time).now()); -> which gives the month
it.strftime(75, 518, id(tm24), color_white, TextAlign::TOP_CENTER, "%d", id(ha_time).now()); -> which gives the date.
it.strftime(75, 518, id(tm24), color_white, TextAlign::TOP_CENTER, "%A", id(ha_time).now()); -> which gives the full day name

Now I would like to do the same yet not with id(ha_time).now(), but with sensor of HA that supplies the datetime, i.e. id(datetime).state

So far I have only seen examples with the current date, but not with random date.

#4

Clear, I only looked at the title and less your sensor … sorry for that. Cannot help further as lack of time (to gain knowledge)
Here it mentions to use a sensor with time as numeric… maybe it helps
Help with time / string conversion : Esphome (reddit.com)

#5

Thanks for the link. Exactly the same question and almost as usual the same solution. Do the formatting with HA and then sent it as a sensor over. No-one seems to be able to do it any other way.

#6 
sensor.WeahterPredictions

Is invalid. Entity ids are lower case.

#7

Would that create the problem? I will try when i get back and can change this.
ESPhome seems to correct this automatically, at least according to the logs. But perhaps not with the strftime command.

#8

Hey!!!
I’m using nspanel as you but I getthe wrong hour. same code as you… but insted of 23:16 I get 06:16. Is like I get +7 hours. My time zone is GMT-3 (Santiago, Chile)
any thougth?!

#9

A thing from the past is that the device should be connected to HA (to get ha data)… so might be a stupid question but did you add it as a device to HA ?

EDIT, there was also another thing, add this to the ha time setup

timezone: UTC-3

might also be 03:00 instead of 3

#10

I think the issue is that HA sends, besides the state, everything in json. So the values are actually json values. I haven’t found away yet to decode the json value to a normal value. It might work then.
I now just resort to having HA do all the conversion and send the values seperately to MQTT.

#11

Going back to your first post. You print id(tm24) but I don’t see a definition of that id.

#12

It is a reference to a font. I haven’t included that in the logs or scripts. But that part does work.

#13

Sorry my mistake.