WeatherFeed Element

The WeatherFeedElement pulls information on the weather forecasts for a specific location from the internet and dispatches actions with specific data items.

The Element in general can load information from and URL that is using http protocol and a simple GET call. As for now the weather service from https://openweathermap.org is tested and working.

openweather.org offers a free service subscription that can be used. Please see their price and conditions and how to get a API key. The API key is required to use their service.

There are other free services that may be adapted and tested in the future.

Using openweathermap.org

The openweathermap is providing some weather information on a free basis after registering by E-Mail. It is easy to get this data because a standard GET request can be used to get JSON response.

The API to openweathermap.org

The API specification can be found here: https://openweathermap.org/api/one-call-api

To build the request URL you need several parameters:

The API key identifies your registered account. You will get one after registration using the menu “API keys”.
You also need to specify the location using the latitude and longitude coordinates. You can use e.g. Google Maps to find these for a specific location. (see link below ir just search).
The units parameter you should specify to get temperatures in celsius.
The exclude parameter can be used to shorten the result to the elements you are interested.

Using these parameters the URL will look like this (with a fake API key): https://api.openweathermap.org/data/2.5/onecall?units=metric&lat=50.23&lon=8.65&exclude=current,hourly&appid=12345678901234567890123456789012

Weatherfeed element parameters

host - The servername to be addressed with the request. e.g. api.openweathermap.org

get - The url of the API. This can include the parameters ${loc} and ${key}.

key - The API key

loc - The location of the weather forecast

readtime - The time between capturing input values.

actions - a list of path and actions that create actions based on values from the server

actions / path - A path in the JSON result from the server

actions / actions - The action to be dispatched.

Configuration Example

/data/2.5/onecall?units=metric&${loc}&exclude=current,hourly&appid=$

{
  "weatherfeed": {
    "home": {
      "host": "api.openweathermap.org",
      "get": "/data/2.5/onecall?units=metric&${loc}&exclude=current,hourly&appid=${key}",
      "key": "12345678901234567890123456789012",
      "loc": "lat=50.23&lon=8.65",
      "actions": [
        {
          "path": "daily[1]/temp/day",
          "action": "device/0?log=temp:$v"
        },
        {
          "path": "daily[1]/humidity",
          "action": "device/0?log=hum:$v"
        },
        {
          "path": "daily[1]/weather/description",
          "action": "device/0?log=is:$v"
        }
      ]
    }
  }
}

Get Raw Result

The effective used URL is shown in the Serial logging when specifying loglevel=2.

To capture the raw result you ma just use your browser. The raw data is also added to the Serial logging when specifying loglevel=2. The data arrives in multiple chunks all starting with body:

Here is a shortened example with comments from the response:

{
  // effective input values
  "lat": 50.23,
  "lon": 8.65,
  "timezone": "Europe/Berlin",
  "timezone_offset": 7200,
  // daily forecast
  "daily": [
    // daily[0] is for today, not of interest 
    { ... },

    // daily [1] for tomorrow
    {
      "dt": 1593255600,
      "sunrise": 1593227824,
      "sunset": 1593286786,
      "temp": {
        // average temp of the day
        "day": 25.54,
        "min": 19.57,
        "max": 26.56,
        "night": 19.57,
        "eve": 25.13,
        "morn": 21.43
      },
      "feels_like": {
        "day": 24.34,
        "night": 19.28,
        "eve": 24.19,
        "morn": 21.43
      },
      "pressure": 1012,
      "humidity": 62,
      "dew_point": 17.82,
      "wind_speed": 5.53,
      "wind_deg": 223,
      "weather": [
        {
          "id": 501,
          "main": "Rain",
          "description": "moderate rain",
          "icon": "10d"
        }
      ],
      "clouds": 60,
      "rain": 4.08,
      "uvi": 8.11
    },
    { ... },
    { ... },
    ...
  ]
}