UART communication via a protective wire in the flat - lighting control

Welcome,

I've been thinking for some time about an idea for communication between uCs within a flat. This is mainly about controlling the lighting and possibly reading the temperature.

The whole thing would be based on a UART, which is available in any cheap microcontroller hardware. The transmission would be based on a single wire (transmitter as an open collector).

Since I have a protective wire to each light point, it could be used as a data transmission medium. It is unused in the lamps anyway, only to be disconnected at the meter. Of course, the one at the sockets should be left alone.

So far this is just an idea and I would ask for constructive criticism

I wouldn't push this wire directly with an open collector, as you can always expect 230V there.
This cable can be used under the condition of galvanic separation and the use of 100kHz modulated frequency as a medium, which is used in data transmission systems in power networks.

JollyRoger wrote:

Because I have a protective wire to each light point it could be used as a data transfer medium. It is unused in the lamps anyway, only to be disconnected at the meter. Obviously the one at the sockets should be left alone.

For the time being this is just an idea and I would ask for constructive criticism

Not permitted under any circumstances.

retrofood wrote:

Not allowed under any circumstances.

One additional free wire in the 230V installation cable is used for the communication network in the lcn building automation system.

spinlock wrote:

retrofood wrote:

Not allowed under any circumstances.

One additional free wire in the 230V installation cable is used for the communication network in the lcn building automation system.

Yes, but it is a four-wire cable, it is recommended that the fourth wire is red.
And for the second time, please write LCN, because a post in which there will be lowercase letters, I will delete to the bin.

Ok, I understand that the problem with using green/yellow wire is due to legislation? It's just that the whole installation is already in the walls and I don't have the option to change it, and the AC data modules are too expensive.

JollyRoger wrote:

Ok, I understand the problem with using green/yellow wire is due to legislation? It's just that the whole installation is already in the walls and I don't have the option to change it, and the AC transmission modules are too expensive.

Yes, legal. The law clearly states that the green-yellow colour must not be used for any other purpose. Only the protective conductor or the protective-neutral conductor may be marked with such colours.
Besides, depriving lamps in Class I of their protective conductor is unacceptable and reprehensible. And no one can assume that the user of the facility will not install such lamps sooner or later.
On the other hand, the fact that the conductors are in the walls is no excuse. The design of the installation is done before its construction, not after .

Nor is explaining that "I'm doing it in my house and I'll remember it" any excuse. None of us are forever and putting future users of the installation at risk of a serious accident is indicative of the predecessor.... saints are, I will not be blunt.

Problem solved, the choice was an additional cable with power and data (twisted pair).