RJ45 Detachable Cables - How To


I recently used a Multiconsole Cthulhu in a joystick I built. To handle the multiple console formats I used an RJ45 jack to accommodate detachable cables. It’s gotten a bit of interest, so I’m going to lay out how to do it.


This is geared towards the MC Cthulhu because its multiconsole nature makes having detachable cords a rather attractive feature. On top of that, it has eight lines for attaching cables. The combination makes RJ45 a fairly natural fit. The concept, however, can be used to add a detachable cord to pretty much anything that needs eight or fewer wires.

Learning about your connectors


This is an RJ45 keystone jack. It’s a fairly standard style for them. It has two rows of punchdown slots on the back with little blades that you press your wire into to make the connections. Most of them will have the pin numbers labeled on the slots. It’s generally not a bad idea to double check with a multimeter to make sure the labels are correct. There are two common patterns for two-by-four row punchdowns and I’ve seen cheap jacks come mislabeled. It’s usually not a problem, though.


These punchdowns cooperate best with solid-core wire. I used some really stiff Category 6 cable, but you can use individual solid-core wires of around 24-26 AWG if you don’t have the cable. You can find toolless jacks that have some kind of device built in to punch the wire down, or your can use a punch down tool. The tooled jacks will often come with a cheap one like this.


To connect your cable to the jack, you strip back the outer jacket, line the wire up in the slot, and punch it down. You don’t need to strip the inner jacket. The bladed slot will cut right through it. When you’re done clip off the overhanging wires.


Now you need to wire your jack to your Cthulhu. For ease of use when assembling the cables, we’re going to connect the pins of the jack to the corresponding columns of the Cthulhu like this:

Pin 1	Pin 2	Pin 3	Pin 4	Pin 5	Pin 6	Pin 7	Pin 8

All of the rows are the same with the following exception: If using the recommended assembly instructions, rows 1 and 2 have a better diode than rows 3 or 4. For the most part, it doesn’t make a difference. But in order to connect it to a Playstation you need to use row 1 or 2, so choose one of those. Solder the appropriate wires to the appropriate points on the Cthulhu and you’ll be done with the internal connections.



This is an RJ45 modular plug. The most important thing to note is the ordering of the pins in relation to the orientation of the plug. This is why we connected the jack to the Cthulhu in the manner we did. The pins are numbered left to right and they’re connected to the Cthulhu from left to right. This will make it way easier when composing the cables.

You’ll need a crimping tool. You should be able to find one for around $10 - $15. They’re cheaper than that if you order them on the Internet. If you’re super cheap or simply can’t find one, I’ve managed to get the job done with in the past with a butter knife and a mallet; individually seating each pin.


The following examples are shown with Category 6 cable because I’ve already got all the console cables I need made and I didn’t want to cut up a perfectly working cable. When making your actual cables you use the actual controller cable for the specific console. The principle is essentially the same, though.

Cut the female end off a controller extension cable and strip the outer jacket back a few centimeters. Line up your wires in the order you need them and trim them all off square.


You don’t need to strip the insulation off of the individual strands. Also, try to leave enough of the outer jacket on the cord so that when the wires are fully inserted, it will be gripped by the plastic bar that punches down in the lower part of the plug. Slide the wires into the plug.


Keep the orientation right and be careful that each wire goes in the appropriate slot. Make sure to double check that each wire goes all the way to the end of the plug. The most common reason for a bad crimp is a wire that’s not fully seated. The thin stranded wire found in most controller cables is sometimes a little tough to get all the way seated. You may need to use a thin pair of pliers or a probe to push a stubborn wire all the way in.



Double check (and triple check, even) that you’ve got the order right and the wires all the way seated. Then put the plug in your crimper and squeeze.


Cabling Specifics

Now we’ll deal with making the specific cables for USB, Gamecube, and Playstation. Thanks to Toodles for letting me use his pin ID photos. Making these cables is just like using an actual ethernet cable. Just clip the unneeded end from the controller cord, strip back the outer jacket a bit, arrange the wires as needed in the plug and crimp. They’re going to be a little tougher because there will be fewer wires and they’re stranded so they’re a lot more flexible. They won’t always easily guide themselves into the right positions. Having some small needle nose pliers or a little probe to guide a tricky wire into place can help tremendously.

USB is used for PC and PS3. An Xbox cord can be connected the same way or you can use an adapter with a regular USB cable.

USB has four wires. The colors are almost universally like this so I’m not going to bother with a pin ID photo. An Xbox cable may have an additional yellow wire. Just trim it short and ignore it. Also, I had trouble with my particular USB cable in that the red and black wires were too thick to fit in the wire tracks of the RJ45 plug. To get it to fit, I stripped the wire, cut about half the strands, and tinned the rest with solder to help them get all the way in.

Color   Purpose    RJ45 Pin
Black   Ground      1
White   Data -      5
Green   Data +      6
Red     VCC         8



Your Gamecube cable will likely have five or six wires but we only need three. We need pins 1, 2, and 3 as noted in this photo. Use your multimeter to find the three you need. Trim the other ones back. You can insulate them if you like, but I just trim each one to a slightly different length. Don’t rely on colors for this one. I’ve seen multiple different color arrangements in Gamecube cords.


Gamecube pin    Purpose    RJ45 Pin
3               Ground       1
2               Data         7
1               VCC          8



Playstation needs seven wires. Depending on your cable, you might have nine. Again, use your multimeter and the picture to find the following. It can be tricky getting them all lined up and seated properly. A set of narrow needle nose pliers can be helpful in getting everything in it’s place. Take special note that pin 6 of the RJ45 plug is empty.


PSX Pin    Purpose    RJ45 Pin
4          Ground       1
7          CLK          2
2          CMD          3
1          DATA         4
6          ATT          5
9          ACK          7
5          VCC          8


Creating a Boot

My cables have a little boot made of heat shrink tubing to make it look nice and clean. I used a piece of half-inch diameter tube to go over the plug, but it won’t shrink enough to fully close over most controller cables. So I have a little piece of 3/16" tube to slide over the larger diameter after I shrink it down. If you want to do something like that, make sure you slide the tube onto your cable BEFORE crimping the plug. Shrink it afterward, of course.



A Word On Mounting

For my joystick case, I cut a rectangular mortise right in the front panel and cut and filed a keystone jack down to fit into it. I think this provides the cleanest look. If you’re not building a wooden case, or your case is already assembled, I think your next best option besides using an actual keystone panel is mounting the jack in a button plug.


You’ll probably have to trim your jack to fit into the body of the plug. Cut the corners down until you can fit it in.



Then, make a hole in the face of the plug. Half an hour with a knife and some hobby files got me something like this.


After getting your wires punched down, slide your jack into the plug. You can glue it in if it’s not a tight enough fit, but be careful about when you do it. Make sure the cable is threaded through the hole in your case either before you glue the jack in or before you solder the wires to the board. Also, don’t forget the nut if it’s a threaded button plug. I feel it’s best to just trim the jack so it fits firmly in the button plug without needing any glue that way you don’t have to worry so much about assembly.


What do you guys think? It’s a pretty basic overview, but lemme know if there’s anywhere I can be more clear.

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Good stuff. Thanks.


Cool but, every rj45 cable I use, has a broken tab and problems staying in the outlet. Was this the most reliable connector in your tool box?


Nice job laying this out. I like the button hole plug idea too. Is that a yenox plug?



It’s been my go-to connector for detachable cables for years now. I’ve had very few issues. There are certainly more durable connectors, but for price vs. elegance, I haven’t found anything better. If you’re really rough with your equipment, maybe it’s not for you, but it’s served me well.

Yep. Just a cheap Yenox plug.


I just bookmarked this thread. Nice info and job. Love the RJ45 connector mod.


If you use the more expensive kind of connector, then the tab wont’ break as easy



Brilliant innovation through and though. Especially the button plug idea.


So you’re saying with this setup you only have to solder to the cat5 to only one row on the MC Cthulhu? Is the Cthulhu able to detect based on which pins are active as to which console is being used?


That’s what I’m saying. The Cthulhu doesn’t detect which row is being used. All the rows are connected. There are multiple rows so you can attach multiple cables. They’re all the same row as far as the Cthulhu is concerned. Toodles made a good piece of hardware. It knows well enough what it’s plugged into to be able to switch modes automatically, for the most part.


Damn, that is really smart of you to take advantage of. If I ever decide to make a stick like this you know for sure I’m going to use your RJ45 method.


Saw this in the Cthulhu thread and thought it looked superb. Nice job. :slight_smile:


There is something I’m still unclear on; how did you connect the Gamecube/PSX/USB cables to the RJ45 cabling? I’m assuming you didn’t just trim one end of each cord and use the existing wires to insert into the heads? If you did do that, what’s the point of the heatshrink, and did you heatshrink the entire cable or just the RJ45 head end?


That’s freakin sweet.


That’s exactly what I did. I crimped the RJ45 plug right on the end of an otherwise normal console controller cable. The heatshrink is just there to make an attractive boot over the plug. It’s totally not necessary for the function of the cable.


So I’m curious, I have a HRAP 3. Can I solder some additional wires onto the PCB of the hrap and put it to the RJ45 keystone jack while keeping the original wires intact? If so, my freakin HRAP is gonna be PSX/Xbox/PS2/GC compatible tomorrow, lol.


No, this isn’t some magical way to add new consoles to an existing controller. Toodles’ Cthulhu board is what allows all of the different console compatibilities. This is just a way to keep the cables tidy while still being able to connect everything. Think of it like the DB9 detachable cable mods people sometimes do.

You could conceivably replace the PCB in your HRAP 3 with a Cthulhu and have all of the console compatibility, but you’re on your own for that one.


Here’s another question for you–

On your button cover mount, is that an OBSM-24 or an OBSM-30? On the Madcatz TEs, replacing the Select button would be ideal (since it’s on the back of the joystick and never gets used) but I believe it’s an OSBF-24.

I’ll probably end up mounting it on the actual case for a cleaner look anyway, but I’d like to know what my options are.


I suppose I’d better get subscribed. :slight_smile:

again, good work. Now to hunt down some clean looking panel mount RJ45 jacks.