Electronics DIY, how to mount/use an RJ-45 socket on veroboard or similar?

[tinnews]

I have some current sensors that I need to mount close to the batteries on my boat whose current they are monitoring with the display and electronics quite some way away at the helm.

The obvious approach is to mount the sensors on a little bit of veroboard or similar (their pins are 0.1" pitch) and then to run some cable from there to the electronics. In addition it would be nice to be able to disconnect the cable easily for installation etc.

I need 8 wires from sensor to electronics so the obvious cable to use is UTP/ethernet, cheap and reasonably robust. (N.B. it's not carrying any load current, these are hall effect sensors with no connection to the circuit whose current is being measured)

However, and here's the problem, I can't find any RJ-45 sockets which can easily be mounted onto veroboard (or any other 0.1" pitch board) as every single RJ-45 socket I can find has the connections laid out as two rows of pins at 0.1" pitch between pins but at 0.05" offset between the two rows of four pins.

So can anyone suggest a way of connecting (in a removable way) UTP cable to a piece of veroboard? I've tried the following approaches to finding a solution but unsuccessfully so far:-

Looking at many, many types of RJ-45 socket to see if there's one which can mount on 0.1" pitch board.

Looking for prototype/veroboard which has either a general layout which can accomodate an RJ-45 socket or one which has specific RJ-45 socket pads.

Plugs/sockets other than RJ-45 which could do what I want, i.e. mini-DIN or similar.

Any suggestions would be most welcome. I could of course simple solder the RJ-45 direct to the veroboard (and tie it mechanically of course) but that would be much less convenient for installation and testing. Solutions using PCB header/connectors are possible but don't suit UTP particularly well.

[John Williamson]

Some of this:-

you eight cores as four screens and four centres.

This:-

very nicely onto 0.1 inch veroboard.

[tinnews]

More difficult to handle than UTP surely?

That's a PCB edge connector isn't it? Are you suggesting I connect the wires to a PCB with an edge connector and then plug the result into the socket wired on the 'main' PCB?

[Toby]

How about soldering a short piece of CAT5 to the board, terminating in an RJ45 plug, then use a coupler to then go to the display like this

[Andrew Gabriel]

Get a short ethernet patch cable. Cut a few inches off one end, and strip and solder this to the PCB. Use an RJ-45 skt-skt adapter in the flying plug, and you now have a flying socket.

A similar option, if you can still find them, get an ISDN terminator, which is an RJ45 plug and socket connected with a few inches of cable.

the plug off and solder the flying socket to the PCB. Pop the socket open, and cut out the two ISDN terminator resistors (other than those, it's 1-1 straight through). Quite useful for making things, such as a poor man's Power over Ethernet adapter: have the same problem with D-type connectors. I found some where you can pull off the piece of plastic which holds the solder pins in place, and then you can bend them to fit a 0.1" matrix board.

[John Williamson]

Not really, I take you're making a (semi) permanent installation, so you'll not be moving it from boat to boat?

There are other multi core cables of that sort of rating around, that's just a handy flat shape. RS should stock eight core low voltage cables, designed for flexing, just to mention one supplier. UTP is normally joined by using IDC connections, which aren't terrifically reliable in damp conditions.

The other way round. Solder the wires to the pins, then just insert the veroboard into the socket. You can buy prototyping boards with edge connectors, or it's not too hard to make your own PCB or get a one-off made to your design. Make your PCB with the sensors on it, taking the connections to one edge, then just use the edge connector as a flying socket, with the wire soldered to the edge connector. On a boat, you'll need moisture protection, which can be done using plenty of silicone sealant round the area.

Or you can get multi way, waterproof connectors which will withstand immersion in daft depths of salt water and put it all in a box. It depends on your budget and intended use.

The gold plated solution, recommended for permanent installation, is to mount your PCB with sensors in a box with gland type fittings for all the cables, using a suitably rated multiway connector for the data lines.

[Fred]

Get yourself an RJ45 patch panel from Ebay - something like this will do:

solder or punch down (depending which connection method is in use on the patch panel) your cat5 cable to the panel. Get an RJ45 patch lead, something like this:

the plug off one end and connect to your sensor, plug other end into patch panel and Robert is your mother's brother.

[The Natural Philosopher]

What is the problem?

one of thousands of hits on 'PCB mounted RJ45 socket'

[chris French]

In message , The Natural Philosopher writes

The problem the OP seems to have is that he hasn't been able to find them with the correct pitch of pins .

[Bob Eager]

The problem is that you haven't read the OP properly. He needs it to fit on 0.1" pitch Veroboard. There aren't nearly so many RJ45 sockets that do that; the one you quote has pins at .039" pitch.

[tinnews]

Yes, that was one way I thought of doing it, a bit inelegant but probably quite effective.

[tinnews]

Yes, as per the previous suggestion, this is certainly a viable way to do it, though hardly elegant! :-)

I used to have an ISDN connection, I wonder if I have any odd bits of hardware lying around in my "bits of telephone wire" scrap box. Good idea!

I have found prototyping board which will take RJ45 sockets, search for Schmartboard, see for example:-

's also a company that does prototyping boards with pads specifically for D-Type connectors:-

might solve your problem, not too expensive from Farnell either.

[tinnews]

But they *all* require a custom PCB, they won't mount onto 0.1" matrix prototyping board - that's the whole problem!

[Matt Balyuzi]

Something like -

[Bob Eager]

Useful. Pity they're in the USA. But their UK distributor:

[D.M.Chapman]

What about something like:

(actually the same thing AFAICS, but that idea)

Or, ready made and cheaper:

[Terry Casey]

buckets above and the other below the board.

Use a 9-way D type and mount with the 5-pin row on the underside, aligned with the tracks, and solder. Select any three pins on the top side and connect to suitable tracks with wire links.

The D connector fixings to the casing also fix that end of the board in place.

If the board is lightweight without mechanical stresses or vibration to contend with, no other fixing may be neede - although that is unlikely in the present application.

The D connectors might also offer better protection against the effects of the damp environment ...

[tinnews]

I'd nearly settled on an RJ45 break-out like that before I found the boards I refer to above.

[tinnews]

Yes, perfect, it's a toss up between this and the schmartboards solution.

[Andrew Gabriel]

of buckets

suitable tracks

You might get away with a 9-way, but for a 25-way the pins won't align with the 0.1" tracks, because D type pin spacing is 0.109", so you'll be almost exactly a track out between the two ends of the connector. Look at the bentpins image above, and see how the pins line up with the tracks at one end, but have become exactly one track out by the other end.

(25 way D connector used in the example above because it connects to a PC parallel printer port, using it as a simple digital output port. The white chips are quad opto-isolators, and the black chip is an octal driver.)