Minimize the XBOX S joypad PCB?

[sju4sju]

Hey,
I don't know much about electronics, and I know that the resistors are probably on the PCB for a reason..
but what is that reason? Analog buttons? 

I don't need the analog buttons, triggers, thumbsticks or memcard slots, so can I just cut away everything bar the decoder chip?
Like, keep the area that contains the chip, some traces to solder to, and usb cable connector.

This would fry something, no?

[HaRuMaN]

You can't cut the PCB.  You have to leave everything as is, and solder to PCB, otherwise it won't work correctly.

[sju4sju]

I can cut anything, I have a dremel!

Thanks for the answer, you clearly don't want me to get electrocuted

I dunno if my first post was clear; English isn't my native language. What I wanted to do was something like prying out the decoder chip, only I wouldn't 'cos it'd be too hard to solder wires to, so I'd leave some board with traces around it, and the traces to the USB cord, which provides power and whatnot to the chip.

Then, the PCB would be small enough to hack into a Saturn joypad shell..

[HaRuMaN]

So are you saying you would just trim the unused parts of the PCB?  Like around the edges?

[sju4sju]

I'd trim away everything but the chip, and leaving just enough of the traces around the chip that lead to A,B,X,Y,dpad etc..
I'd probably be left with just the center of the PCB, like a rectangle stretched vertically, as the USB connector's located at the bottom, and the chip's at the top.

[HaRuMaN]

Feel free to try it if you wish, but I'm pretty sure that doing that will ruin the controller.  Just my $0.02.   

[abzman2000]

well if you are ever to be successful, if this is even possible, then this guy has some useful info: http://spritesmods.com/?art=xpad

[DaveMMR]

Knowing very little about the Xbox controller's PCB myself, I could only guess that it would be a quick road to ruining it.  Unless you know EXACTLY what every little trace leads to and what every piece does, it seems like it would be educated guesswork.   I don't know how experienced you are working with PCB's but unless you know the circuits like the back of your hand, I wouldn't attempt to start selectively removing bits and pieces.   Just my opinion.  Proceed as you will.  

[sju4sju]

Thanks for your replies!

I just desoldered the memcard slots, thumbsticks and analog triggers.. initially when I tested it, the pad seemed to work fine, but when I ran a button config in an emulator, I saw that the left analog stick was constantly moving southeast, and other weirdness

I thought I'd heard of some consequences from removing the thumbsticks.. but is there a solution?
If not, I'll just solder everything back on, and throw the joypad back in the box from whence it came.

[abzman2000]

please describe the other symptoms because I don't have any intention of reconnecting this joystick for a while, like the other joystick, or the triggers

well, I decided to take a crack at it too because I had an xbox controller with a broken joystick, so... I'm tracing connections right now.  also, maybe the joysticks' variable resistors were not zero when it was centered so you may have to add resistors.  check the values between the center and either sides of the POTs to confirm

update: to begin the brain-meltingly tedious act of eliminating superfluous components, Q4 seems to drive the right rumble motor and thus can be removed.  Q2 the left.  the transistors Q1 and Q3 appear to drive the transistors Q2 and Q4, odd...

is it possible to bypass the 3 port usb 1.1 hub and still have it work?

[sju4sju]

Well I guess the symptoms were the stuck analog bits.. I could only see the left thumbstick moving, and both shoulder buttons, as I was checking with "SNES hardware test" in ZSneXbox But I'm guessing the right stick was stuck too.
Oh and I think maybe the ABXY buttons too, because when testing with the SNES game Fatal Fury, the character would suddenly punch. Didn't happen very often..  The ABXY buttons are analog btw.

3 port USB hub? You mean the memory card slots? I just desoldered it, and took off the plastic parts.

[abzman2000]

there is a 3 port hub between the controller IC and the cable to the console.  the small atmel chip is the hub, one port goes to the controller, and one to each memory card slot.  described here: http://spritesmods.com/?art=xpad&page=2 "There's an USB1.1 hub made by Atmel especially for Microsoft (but aside from a few descriptor-strings, not too different from a normal hub)" this hub might be needed to identify the controller to the console

[sju4sju]

Hmm k.. I have a Microsoft XBOX S controller.. and there's only 1 chip on the pcb

[abzman2000]

there are at least 3 major ICs, an ST one, an Atmel one, and a TI one (no name, but a logo)

[sju4sju]

Here's mine; removed thumbsticks, memory card slots, and shoulder triggers


zoom


zoom

[abzman2000]

we have WAY different board revisions, and I'm much more optimistic about yous than mine, although the bit about the rumble motor transistors appears to apply

[HaRuMaN]

There are two models of the Xbox S controller.

[northerngames]

what are you trying to accomplish and why does it need to be chopped apart?

depending on the pcb version your using if you discconect the triggers and such it cause's unwanted signal press's for other button signals and the same with the thumbstick pots if it is a controller version that share paths with other signals.

there are so many different voltage's and components running back and forth from that chip and to eachother that your never going to get it down to the chip itself with trace's coming off it and solder to it like it is a pic chip or something like that.

 look at all the trace's running to and from that chip and how hard it would be to solder wire's to almost all them along with the required components that you would need to re-add since they were removed you must have some mad soldering skills if you think you can swing it but remever what went where 

also you will need to add a resistor if you want the analogs to stay at a centered dead zone otherwise there going to be fully stuck on in a certain direction signal and cuase the pulling to one side constantly..

[sju4sju]

I see 
Well I wanted to minimize the board to put it into a sega saturn joypad, but it seems that this is beyond my skills, then.

I've previously built an adapter box with a psone pcb inside that connects to my xbox with a converter:

But I don't really like having to connect pads to that box.. I dunno why.. I also think most dsub15 cables are too stiff.

I have another idea though.. aren't keyboard encoders pretty small? I though about putting one of those into a pad. I think all the XPort emulators and MAME supports keyboard input, also XBMC, and I hope FBAXXX

[northerngames]

how about an actual sega saturn controller that plugs into the xbox controller and then the xbox controller connects to the xbox/pc?

this has been done and I should be able to find that post to do so.

it is possible to make the xbox controller an adapter to allow older console controller to plug into it.

let me know if they may interest you but it would be alot faster, easier, durable, cleaner etc.

[sju4sju]

That's exactly what the picture above your post is showing

[northerngames]

kinda yeah but the plug mounts on top of the actual xbox controller case so no psone stuff is needed but I guess it is the same concept in the end pretty much.

I did come across another mod where they stick a psone or ps2 controller guts into the sega saturn controller case not sure if it was ps1 or ps2 but would that work since you know how to wire the ps stuff to the xbox?

[madgammer]

wouldn't it be easier to just buy one of those smaller controllers?