What principle of communication of smart home modules to choose?

Question

Arduino

I decided to build my smart home system on the Arduino platform. Light on cotton, alarm with notification by cell. In general, everything is in this spirit. But I ran into a problem. The modules will be located in different corners of the room (5M X 5M).
The crux of the matter is as follows. How to do it better.
1. Each module is autonomous, 2.4 GHz communication and its own power supply.
2. Run wires from the head module around the room and power the secondary modules through them.
Thank you in advance for your response.

Answer 1

When I did repairs to each Switch, sockets and chandeliers brought out a twisted pair cable.
True, she hangs out so far without doing anything :)

Answer 2

Wifi probably ...
For not smart technology - IR, through the module.
In general, do you need it for you?
If you want to be confused, then be fooled.
And if not, then look at what xiaomi offers (without any pops) and buy a normal working system.

Answer 3

As a terrible hater of wires, I prefer the radio. Power can be taken from any outlet, or even from batteries if there is normal sleep and infrequent work, but data wires will have to be pulled from the server. Yes, and for radio, you can come up with many protocols, but for a wired system ... Modbus / onewire, perhaps.

Answer 4

there is another option, how to use it as a source of data transmission, this is the voltage supply network itself, for small data flows it should be fine, but unfortunately I have not seen such simple systems from ready-made modules (if you are directly afraid of radio waves), but if you met such modules, write me glad to learn something new, the method is very ancient, but as an option you can use

Answer 5

Version with RS485, 4 wires RX , Tx, 12V, you can put several devices on this bus. Near the arduino (ok) there is a small block (dc-dc) with a 5V converter (so avoid voltage drops on the wires at different connection points) and if you need about 12V for relays and other more voracious devices