Having tried Home-Assistant I can see how it can be really powerful once setup (and that’s probably where the issue lies, configuration is too much code driven with no UI at all).

However there are devices that are not yet supported by Home-Assistant (e.g. CurrentCost) and in addition, I can’t have both Home-Assistant and DomotiGa connected to my RFXTrx.

This means I’m looking to use both platforms and find a way to get them to talk to each other.
I already know how to send commands/updates to DomotiGa via JSON-RPC so that will be my first approach.

I’ve created a simple shell command that I use to update devices in DomotiGa:

shell_command:
  set_domotiga: curl -sS -X POST -H "Content-Type:application/json" -H "Accept:application/json" -d '{"jsonrpc":"2.0", "method":"device.set", "params":{"device_id":{{device_id}}, "valuenum":"{{valuenum}}", "value":"{{value}}"}, "id":122}' 192.168.0.24:9090

then in my automations, I call this function with the correct parameters. See below example for my Nest Thermostat (virtual) Device on DomotiGa:

- alias: Update Nest Status
  trigger:
    - platform: state
      entity_id: sensor.hallway_thermostat_hvac_state
  action:
    - service: shell_command.set_domotiga
      data_template:
        device_id: 122
        valuenum: 2
        value: '{{states.sensor.hallway_thermostat_temperature.state}}'

I’ve also tried to install Home-Assistant on my Raspberry Pi as I do like the Web interface, but it’s overkill and take too much overhead when I only need to monitor my GPIO ports. My own script is better in that effect.