Hey Mustafa,
Replying publicly to your question: I did indeed have an issue with modbus TCP before, see Modbus TCP integration
My issue was different though in the sense that I wanted quick feedback (push button events). In the end, I did find that the vendor of the hardware provided their own translation of the modbus events into websockets, which I in turn then translated into MQTT events, for which home assistant has excellent support.
If you only require polling your sensor values periodically, I would suggest just to use the modbus integration directly provided by home assistant: https://www.home-assistant.io/integrations/modbus/
The custom component you mention is a step further then just using the already available modbus integration. A custom component means you hook your own code into the home assistant ecosystem. Check the development docs for that: https://developers.home-assistant.io/
As I understand it, for developing your custom component the idea is:
- provide some (python) code that can interact with your sensor (since it’s modbus, this will probably be a thin wrapper around pymodbus, https://pymodbus.readthedocs.io/en/latest/).
- provide your custom component code that calls this stand-alone library.
The home assistant community likes this approach because:
- it doesn’t need to live (and be maintained by) in to core home assistant code – it gets pulled in instead when required
- pushing for more open libraries means an overall global better IoT open source landscape
Another thing you mentioned was a hassio-addon. I don’t use hassio myself, but I suspect this is some kind of addon to make it possible for you to connect your (containerized) home assistant core instance to the peripherals on the host system (?) Before you get any deeper into that, please make sure you understand the networking model of hassio, the addons and home assistant core: https://developers.home-assistant.io/docs/supervisor#architecture.
tl;dr: I would recommend to check out whatever’s just possible with the built-in home assistant modbus integration, before trying anything else.