RJ45 connectors


I had a project idea and I was wondering if this is even possible.

The project involves RJ45 connectors but they aren't used for ethernet.

So I would have an esp32 that is somehow connected to 8 RJ45 sockets. Then I have 8 RJ45 plugs with a short bit of ethernet cable ( only connected to that one plug ) where 2 wires are connected to create a circuit ( each plug has 2 different wires connected to each other ). So when I plug in one of the plugs into any socket, I want to figure out which of the plugs where plugged in and into which socket.

I also want to add some LED's that show red if no plug is connected and green if there is a plug connected. For this I was planning to use one of those RGB LED strips.

no idea if this makes any sense or is even possible.

thanks for any

Hope this makes all sense

Hope this makes sense?

Yes it makes sense. Make the same pin always ground and connect your selected pin to this one.

The only snag is that you must avoid people thinking it is a normal RJ45 socket and lead.

What is different about each plug that will allow you to know which one is plugged in or is it good enough to know that any of them are plugged into a particular socket ?

the plugs will be numbered and represent a physical item that an employee can borrow. So it would be good to know exactly which physical item is available and which one isn't. Yes you could expect the employee to plug a certain plug into a certain socket but I don't think they will. For that reason it would be good if it could be plugged into any socket.

Is there a reason you need to used different pairs in each RJ45 for your circuits?

If you use the same pair in all 8, you will have 6 contacts left.
One for gnd and the other five to make a 5bit ID code.

What is the application, what are the circuits you are connecting to?
Is the signal digital or analog?

Thanks.. Tom.. :smiley: :+1: :coffee: :australia:

Ok let me to to explain a bit more.

So each plug would represent a different type of machinery an employee might need/want to use. Before they get the machinery, they will go to the setup and remove the rj45 plug. The ESP32 monitoring the sockets will be able to detect and identify which plug has been removed and send a request to one of our servers which will then update the database to show that a certain piece of machinery is used by someone. When the employee has finished the work, the plug is returned and the system update.

So I thought that if an esp32 can simply check all 8 pins on all 8 sockets and if the plugs have different wires connected ( ie machinery A has wire 1 and 2 connected in the plug and machinery B has wire 1 and 3 ) then it wouldn't matter in which socket a plug has been inserted.

Does this make any more sense?

So just to be clear, the rj45 sockets would only be somehow connected to the esp and the plugs would only have a maybe 3 inch cable where pins would be connected and so would create a sort of loop if that makes sense.

Thanks for the help so far.

Might it not be easier to use the "iButton" system which is sold for this specific purpose?

Reasonably inexpensively available on Aliexpress as well as other vendors and the support is in the Arduino IDE libraries.

As I understand @stephan2307 he needs simply a coding system. Each plug is coded differently, and the esp32 detects which of the plugs are inserted and which are not.
I don't think it as anything to do with a 1-wire system.

How many employees and how many machines?
Your description is still a bit cryptic.
Have you considered RFID cards, or even an RFID tag on the equipment?

So, it doesn't matter which employee, only that the equipment is "in use"?
Again, how many tools/machines/equipment? (It would help if you were less generic).

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