Best Options for Controlling SmartHome with Custom Android Software and Zigbee

Hi,

I want to make a SmartHome, but control from my own software on Android.
What options do I have that exist on the market, or maybe make my own system on Zigbee?
The enthusiasm is there, but I don't want to break down the door at first....

Greetings.

And what elements is this system supposed to have?

Several sensors (lights, CO, etc.) and 'relays' (switches in 230V sockets), measuring electrical power consumption for the whole house. I have not yet established the full functionality.

By 'own' do you mean your own software on Android? Some tablet that manages everything?
Or is it better to use some open source ?
Such as HomeAssistant, Domoticz, etc.

The most interesting option is to write your own program under Android. Rummaging through someone else's code takes time and is not as rewarding .

The program in Android will manage the whole system. At the moment I do not intend to manage via the internet. Possibly in the future when I add web control to probably need to add some kind of tiny that will be the main computer controlled from a smartphone.

As I understand it, the only option, in the case of a raspberry for example, is to connect everything via a gateway that I have purchased?

I can't add wiring, so the transmission will only be by radio (zigbee).

marycyś wrote:

I have the enthusiasm, but I don't want to break down the door at first...

- in the time it takes to realise it, the enthusiasm can pass. And a lot of times... Imagine how much time you need to implement the first, simplest functionality.... An ambitious idea, but does it currently make sense?
If you use a zigbee gateway from one manufacturer - you limit the number of possible devices, access by default through the manufacturer's servers, etc. If a multi gateway - you would have to write everything from scratch.
In my opinion, it is better to use what is there as a basis for something that already exists - e.g. as above HA or HA-based AI-Speaker. You can use MQTT, or install e.g. Node-Red and practically create your own functionality (as far as the devices themselves are capable).
As a basis, you would already have support for thousands of devices and zigbee multiband, access via web or app. And you could focus on functionality.

In HomeAssistant, Domoticz, etc., can you download data to your programme in android?

That's probably something you'll have to check for yourself, I suspect no one knows exactly what you mean when you write "your program in android".
There are dedicated apps (there's one for HA, AIS, domoticz I don't know), you can use via the web, so it's probably possible to "extract" data, but you'll have to check this for yourself.

Yes, you can. I myself know probably a dozen ways to communicate bidirectionally with Domoticz and HA.
The first and most important is MQTT, which has become the standard for IoT device communication. Others are APIs, Http, Python ports and plugins, LUA, Blockly, JSON, YAML, communication via UART, Rs485, TCP, using e.g. modbus, CAN, winsocket etc.
So I'm sure you'll find something that suits you.

Which system: Domoticzem and HA, is more universally designed?
As I understand it, in both cases you have to create an account on the server?
Is the MQTT protocol only between devices in the local transmission network (home), and further on all data goes to the server?

Home Assistant is more versatile, but at the same time it is more difficult to so called enter to begin with
No. These are systems that run on a local machine. Most often, an RPi3 or RPi4 will suffice to start with.
The MQTT protocol is a network protocol. It does not matter what kind of network it is. Usually, communication with the broker takes place locally, but there is no obstacle to connecting yourself via MQTT to, for example, some sensor from a distant plot of land as long as there is Internet access.

That is, the raspberry itself collects data from the sensors and sends to the 'relays, but does there need to be an intermediary (gateway) if the whole thing works on zigbee (or BT)?