So for the past while I've been reading Tech talk up and down, researching how controllers are wired, and subsequently the mods that go with them. I, like most pad warriors felt left out on all the modding fun.
So I decided to see if it was possible to dual-mod the Madcatz 360 Fight Pad that I use all the time, utilizing the highly used and accepted Cthulu + Imp set up created by Toodles . In this thread is a sort of "How I did it," how-to guide. The reason being the free-form nature of this mod, and its semi-direct course.
After thinking long and hard, I wanted 2 goals achieved by the end of this ordeal:
1. The controller works on both an XBOX360, and a Playstation 3, with all buttons functioning, no skimping.
2. Everything must be INTERNAL, no DPDT switches or anything. When you look at it you see just a normal pad.
To do this mod it requires a few tools:
1. Multimeter, has multiple uses but mainly will be used for continuity testing.
2. Soldering iron, because there's no way in hell that this could ever be a solderless mod.
3. Solder, I used .015 silver solder, because it's the smallest Radio Shack carries.
4. Wire, I used 24 gauge stranded initially cannibalized from an old ethernet cord... that was a mistake, I switched to 28 gauge stranded from an old IDE cable, at this precision level, 24 gauge seems immense... go with a higher gauge, trust me.
4. Electrical tape, it has many uses.. but mostly wire management and isolation.
5. Hot glue gun, this isn't technically required, but covering some of your connections is a fantastic way to make sure you don't have unexpected shorts in the future.
6. Proto-board, you'll see why in a little bit.
7. Access to a dremel, you'll be doing a lot of custom fitting... and a knife just won't cut it (no pun intended).
Understand a few points: Elapsed Time: Upwards of 30 hours, this is not an afternoon project unless you're a magician or are just a really big badass. Level of Difficulty: Hard, do not attempt this unless you're super confident in your skills, and possess the ability to troubleshoot difficult issues. *Note*: This will DEFINITELY void your warranty, seriously...don't even dial the number for tech support. As far as support goes, unless it's a basic question he's willing to answer, don't bother Toodles if you try this and something goes wrong. It states in the welcome paper that he doesn't support dual mods (although he helps as best he can), this is something I know he will not help you do. You can contact me, but unless it's a basic question, it would be extremely hard for me to help you troubleshoot issues. From what I understand, Toodles no longer sells the Cthulu kits, and will not be doing so until he releases the ChImp, so even getting the parts to do this is a challenge in itself.
So let's get started on our mod!
I ordered the Cthulu PC/PS3 kit with a few reserves. I wasn't sure how big in comparison it would actually be to the fightpad, well here's the comparison:
No way that's fitting in there as is, let alone try to stuff an Imp board in there, so what do we do? We improvise! Using the trusty multimeter, I mapped out the PCB's traces and how everything fits together:
Using this, I put the kit together on my proto-board to see just how much space only the PARTS would need, and also to test out my mappings:
To make sure I was correct, I cannibalized an old USB cable, and plugged it into my computer, SUCCESS!
Now that the mappings have been confirmed, it's time to put the parts on a more... permanent space, so I went to the local radio shack, and nabbed a PCB that would fit my need, then colored the top of it with the bus locations to make the part positioning easier:
Looks pretty good, let's compare to the original layout:
Looks much smaller, huh? Again we test out our build to make sure everything is Kosher, using a continuity tester the whole way through in order to stifle a chance of shorts.
Now that we've gotten the kit rebuild done, it's time to bust out the dremel and do some custom fitting!
First thing's first, with the way the new PCB is situated, I've decided to put mine on the right hand side, just under the 6 button section... this is where there is no defined way to do this, engineering is just as much an art as a science.
We get rid of the pesky stand-off that's in the way, don't worry... it doesn't actually help with stability, and everything's going to be snug in the end anyhow:
After a bit of sweat and cursing, here's how it should sit:
After you dremel the PCB, clean off the solder side of it with some rubbing alcohol in case there might be some slivers of trace that could possibly cause a short.
Once that's done, it's time to custom fit the Imp board. Toodles, your PCB is beautiful... but in the name of science it must be cut!
I apologize for the super blurry shot, but basically I notched out the bottom of the board. *Note* If you do this be SUPER careful how far you dremel into the PCB, taking note of where the traces are on both the front and back. Any further than I went and you've just managed to cut the traces, and are SOL.
Fits pretty good eh?
*Note* the wires coming from VCC, GND, D+, and D-, were way too large (radio shack wire has a ton of insulation...stay away from it if you're doing tiny work like this), so I swapped them out for 24 gauge stranded from an old ethernet cable.
Now that the basic idea has been mapped out, it's time to wire up the Fight Pad's PCB, which is something anyone who's padhacked will find very familiar.
Here's some references that I grabbed from the "Soldering a Madcatz Fightpad?" thread, this came in handy... they may help you too.
While doing this portion, you need to cut the USB cable for the dual mod. I fucked up HUGE on this part. If you simply cut the wires and solder to the points already there for VCC, GND, D+, and D-, then you're good to go.
I tried to desolder the points to be smooth, and in doing so was impatient and subsequently tore out the trace pads of a few spots. This had me severely worried, because without those pads you can't access these important points.
I spent the better part of 2 hours trying to figure out how to fix this massive fuck up, and in the end I found my solution. Even with the little trace left, I found where the + side of the coupling capacitors were located, and attached them there. Here is what it looked like, it's NOT my proudest solder job:
As you can see, B1 and B2 needed to be attached in a more non-traditional way, but after connecting it this way I plugged the set up back into my proto-board and re-tested. It booted up and windows recognized the fightpad :pray:
With that out of the way, I hoped to keep screw ups to a minimum from here on out. If you do anything like this, I hope you don't have to connect it like I did.
The next step is straight forward, it's time to solder to the data points on all the buttons and directionals.
What's not straightforward is how careful you need to be while doing this, because when the button is pressed it needs to touch the contact pretty level, so the idea is to solder to the tiny "off-shoot" spot on each of the connections:
Don't razz me on how much wire is stripped, it looks like a lot...but really it's a tiny amount that ends up being large on this scale. Pay more attention to how I've routed the wires, because if you want things to fit together, it's a good idea to keep those data wires as out of the way as possible.
Here's another tip, you don't have to solder to the home trace directly, there's a small pad above it labeled "S12" that you can put your data line on, which keeps the wire out of the way of your home button:
When you're finished it'll look similar to an octopus, hehe.
The next step is up to you, but I wanted to make sure that the Imp board would recognize both connections, and switch correctly. So I connected the 3 boards together, doing the most precision solder job on the USB points the Imp has.. seriously, those things are fucking tiny:
Don't mind the scotch tape, I didn't have electrical tape at the time, but have since switched it out. Also you may notice the USB cable is coming out the back side of the Imp, this is because of how I notched the PCB, it will actually sit face down inside of the fight pad.
Plugged it into the PC, and it recognizes the Fightpad. I tie the "home" wires together (1 from the fightpad, the other from the Imp's "guide" spot), and push the home button. The PC recognizes the Cthulu, that means it switches correctly!
Now comes the delicate work, soldering in the data wires to the Cthulu's new PCB.
I labeled my connections, and placed the boards in the general vicinity of where they'd finally be. After that, run the cables 1 at a time to get the idea of how long you want to cut each connection, and solder it in place where it should be.
This is everything soldered into place, every single connection has now been made.
After I did this, and shoved everything into the pad for the first time, I ran into a SERIOUS problem.
I plugged the USB cable in, and a windows pop up told me "Surge on the USB port," basically telling me I had a short from VCC to GND somewhere in the design.
After nearly crapping myself, I thanked whoever designed the overload protection, because it saved not only my project but my computer's USB.
Taking everything apart, I took another look at the likely suspect, and found that one (1) strand of the USB's 28 guage had disconnected from VCC and floated to the ground spot. That's all it takes to set your shit on fire if you aren't careful, my boss told me I should've been using a USB hub with an internal fuse anyhow... lesson learned.
I decided at that moment that all important connections (READ: Power) needed to be insulated and held firmly in place so nothing magically moves and in turn... destroyed someone's USB port.
This is where the hot glue comes in, bust that out and prepare to douse a few of the connections, both front and back.
The reason I say back is because I ran into yet another power short problem, when cramming things together for the umpteenth time I had another short caused by a case screw, which turned out to be shorting the VCC and GND buses on the custom made PCB.
See the little black screws to the upper right of where I showed the standoff? The GND and VCC buses were resting across the top of one of those... yeah, tiny oversights are what screw you over.
I removed the screw, and started up the hot glue gun, then taped the Imp to make sure the solder side doesn't connect with the Fightpad at all:
I also used the tape for some wire management, coming in SUPER handy.
Once everything is set, and you're subsequently covered in hot glue because that stuff is undoubtedly the most messy substance ever :rofl:, do like you did when playing Tetris, and fit everything together with an artful hand:
If you used glue, your wires should be safe and secure, with no fear of coming loose or causing a fire.
Now put the back on, and you have, what appears to be, a normal Xbox 360 Fightpad... but in reality, it's much more on the inside.
That wasn't so hard, was it?
Now look around, your desk should look like it's exploded from all the crap you've just done, I know mine sure as hell did:
Dr. Stein believed in me the whole time and fed me words of encouragement as I burned myself, cursed, and sweat for the better part of 2 weeks.
Thanks for your time, now go create something crazier than this!