I've been pretty dormant in Xbox modding for a while now (well not really, I just don't publicize my work).

In any case I wanted to tackle an interesting project. Every 360 owner knows the D-Pad flat out sucks, and with fighting games like DOA out and SF2HF and UMK3 speculated to hit the XBLA soon a controller with a solid d-pad is important. While the Playstation pad is widely popular, most hardcore 2D fighter fans agree that the Japanese Saturn Pads are some of the best fighting games pads ever made. Not to mention picking up old Saturn pads and joysticks is relatively cheap. If you really want a PSX pad there is bound to be a converter eventually, whereas it's highly doubtful you'll ever see one for the Saturn.

This of course involves gutting a perfectly good 360 controller... luckily I just picked up 2 wireless controllers for $20 a pop, both have analog stick problems, which make them perfect for this mod (considering we wont be needing analog sticks).

Aside from that I'm going to take a slightly different route then other converters. Rather then taking the EASY route and gutting a Saturn controller, I'm actually going to convert the OUTPUT of a fully functional Saturn controller. This means I'll have a Saturn controller port (stripped from a cheap controller extension cable) so that ANY Saturn game pad or joystick can be used. The whole thing will be wireless to boot so I'll have a little black box sitting on my coffee table that the Saturn controller will plug into.

The Saturn pads are relatively simple beasts, basically all the buttons are wired into a single encoder that is nothing more then four "4 into 2" multiplexers running from the same signal wires. It's so simple in fact that you could very easily build a Saturn joystick of your own from scratch using off the shelf parts (from digi-key, I'd have a heart-attack if you could find that stuff at the shitty-shack).

A good primer and where i got most of my starting information is over on gamesx.com they have great AV and controller pin-outs and diagrams if you're ever doing console mods like that, especially on classic consoles. You can find the Saturn controller page here: http://www.gamesx.com/controldata/saturn.htm I should warn you that Kashi's diagram (the first link) has some incorrect labels that if followed would fry either your controller or you Saturn... or both. I've contacted GameSX about it so until they fix it be weary.

From that diagram you can see the Multiplexers converting the direct (parallel) button input into the muxed Saturn Connector output.

Basically by simply reversing this process using demultiplexers I hope to convert the Saturn Controller's muxed output back into a direct parallel output that I can then map to the specific points on the 360 controller's PCB. Simple right?... I thought so

One other thing, the signal wires need to be generated by the "console" since it's a 2 signal mux basically we need to create a 2 bit binary counter. this can very cheaply an easily be made using a 555 Timer and a dual J/k flip-flip chip. The signal wires will continuously count 0 through 3 and send that back through the controller cable to feed the multiplexers at the same time it feeds the demultiplexers. As an added bonus the Saturn protocol has a 5V feedback wire that lets me know when the controller has been connected, using this I can make the whole circuit go dormant when not plugged in, this will certainly save power.

So without further ado Here is the preliminary schematic I've drawn up (literally) for the above described process. http://www.web-nine.com/files/SATto360/SATto360RevA.pdf

I've left out values on the timer circuit as I plan on playing around in the prototype to get a feel for a good speed, The faster the better but I would assume there is an upper threshold somewhere.

I've ordered all the parts and they've already been shipped, I plan on diving into this as soon as they arrive. and I'll post here with any progress

In the mean time I'd like some feedback. I've never actually worked with muxers before. My biggest concern is that the parallel outputs get strobed when active by going high whenever the signal isn't directing output to that pin on the demultiplexer; which would work horribly for a controller. Can anyone who's worked with these before lend some output? I would imagine if that's the case/worse comes to worse I can rig up something to bleed the signal enough that it wont drop off until it's finished a complete binary count cycle, thus removing the strobe effect. Alternatively i could use timers in a monostable operation to hold low whenever it gets a low pulse. Neither I feel are really solid solutions, so again I welcome any advice.

Ohh.. Ohh, ohh, okay. I understand...

I look forward to seeing this work

If i understand correctly, it sounds a bit like this mod

http://www.althack.com/index.php?option=co...id=50&Itemid=37

But you aren't hurting the saturn controller at all, good idea

Yes exactly, rather then sacrificing a classic controller I intend on simply converting it's output. That gives me access to a number of controllers available for that system.
Something like an NES/SNES controller would be simple as well as that's just serialized data, you'd simply use a shift register in as a serial to parallel converter. thought the hardest part there is finding a "controller port" to use to plug it in.

I can't wait to see what you come up with. Keep up the good work.

very interesting concept..

great idea, especially for SF2.
there's no doubt in my mind the saturn is the best pad for 2d fighters.

if you can get this working 100% you'll have a blast with SF2, the nice loose disc pad and the 6 face buttons is perfect.

Edit-Nevermind, i said a load of stuff you already knew Shows me up for not reading the post properly...

I got my parts in today...

Before I got started I had to finish modding a DVD drive for another project (the shipment in-cluded one last part I needed for that one). Once that was done and tested I started in on this one.

Here is the prototype circuit thus far:

I've thrown a pin header on the Saturn cable, Opened the Saturn controller to test all the pins for accuracy of the pin out on GameSX, and I built the first half of the circuit. (the timer and 2 bit binary counter) which are all working properly up to this point.

Tomorrow I hope to devote another hour or two and should be able to get at least one of the demuxers wired up and see if this thing actually works If the results of tomorrow are successful then all I've left to do is bust out the soldering iron and make it look pretty

Haha thats awesome, <3 the Saturn.

have you tried the 2nd gen saturn pad?
much better imo

I plan on using this with a Japanese saturn pad, maybe even modifying the circuit to work with the analog pad.

for now I'm using the trashy 1st gen pad, because I'd hate to fry one of my USEFUL controllers in the prototyping process.

This is intense.

You know where to find me if there is anything I can help out with.. though I doubt it =)

Very nice project.

/pablot

have you ever used multiplexers at all before?

If they don't work out I'm thinking I might just make this a single chip system using a PIC or Amtel... if it comes to that I might need your help

I have actually taught a bit of digital electonics at my uni, so yeah, I have come a cross a few mutlplexers so to say. Anything specific you wonder about?

well my biggest concern is with the demultiplexers...

If I have 2 select wires making up a 2 bit binary number, and 1 data wire coming in... and 4 outputs (Y0-Y3). I'm wondering if when the select wires read 00 and the data signal is 1
will Y0 stay at 1 when the select wires read 01 and and the data signal is 0 (for Y1)? etc.

in other words do the output pins lock their data until the select pins come around again?

ok unfortunetly this isn't work as I'd hoped...

The demultiplexer is ... demultiplexing... but when it switches from one select to the next, the unused selects go low.

I've taken a video of this with the clock speed slowed down so you can see what I'm talking about:

http://www.youtube.com/v/49Sul8H7M9g

hey twisted, youve helped me a ton in the past, so now maybe i can help a little, i just finished my EEE electrical engineering class at asu, we covered demux's quite a bit, basiclly, the output of the demux will corespond to the decimal value of the binary input, so you get the input 00 then Y0 will go high, the rest low, you get 01, Y1, and so on and so forth. Now you said you dont want the unused signals going low? what do you want them doing?

when the binary select signal changes I want the output to stay latched until the binary select matches that output again....

because with it reseting every time the select signal changes I get a pulsed ouput...

which when tied into a controller is like having "turbo" on every button.

out of curiosity what are some of the uses you had for a demuxed output? I can't think of many WITHOUT latching outputs.

if there is no easy way to do that I might have to scrap what I have and go with a programed chip solution.

you can use a demux for running a single input to multiple outputs, like in a very very simple cpu we used a demux to select which control set we were at, however, it was a 4-16 4 bit demux, as far as your demux, so do you want it to hold the output for 2 cycles? is that what you mean?

yeah, sorry man.. that ain't how you usually use them..

Demultiplexers can be used for example to control which FF you want to latch.. so you could solve it with four extra latches. Use the four demultiplexer outputs to control the "input enable" or something on the four FFs and connect the input signal (the one you preciousely had connected to the input of the demux) to all four FF inputs. Then it'll step through all four latches and letting them change the output one at a time. There are easier soultions though. I'm going away for the weekend but if you want me to I can scetch up a soultion on how I would have solved it, on sunday that is.

But I'm guessing that by the time I'm back that this will be solved and in history.. =)

/pablot

well.. I took a quick look at it. This could be done with four flip flops, a clock, a counter and a demultiplexer/shiftregister. nothing else should be needed. Maybe a few extra gates depending on what flip flops you use. You might even be able to "steal" the clock from the 360 controller to save on components (and thus cost and space). (that is, per mutiplexer on the saturn, so in total 16 ff's are needed, the other parts can be shared between the ff's, damn.. thats a few FF's actually!)

hm.. giving it some further thought I think it would be easier for you to just program a small microcontroller.. all you need is at least 19 I/O, the timing isn't crucial so an internal oscillator will do just fine. You could get away with a single pic or atmel controller costing you about $2-$3 or something. Takes away the easy part where you don't have to program anything but wireing will be alot easier and it will be more compact. The price will be pretty much the same too, its a question of cents. But as I said, problem is that the normal hobbyist won't have a atmel/pic programmer at home.

Code should be really easy though.. just a counter doing the 2 bit counting for the multiplexers, then 4 inputs that you check to update the 13 outputs. And then slow the whole thing down to a acceptable clock speed.

yeah That's pretty much the conclusion I came to when I realized the demultiplexer's outputs didn't naturally latch... there area few ways I could get around it but none that are simple enough to be worth implimenting...

If I go the MC route I can get the job done with one or two chips.... still alot of outputs though, do you have any suggestions as to which PIC or Amtel I should use? I've used PICs in the past (years ago) but I don't have any of the software or equipment for either at the moment. $$ isn't too big of a problem, and I don't mind spending it on the software/flasher because I can use that stuff for other projects.

EDIT UPDATE: I just put an order in for a "PICkit 2 Starter Kit" $50 it comes with a PIC16F690, a serial Programmer that works on a number of chip types up to 20pin PDIP, prototyping board software and 12 lessons to get you started.

The chip offers 18 I/O... (1 too short I know..) So I figure I'll leave the start button out for now and I' can built that into the converter box alongside the guide and back buttons. I have a few other "creative" ideas on how to make that work...

I wanted to order a few more chips but all of the ones I liked were back-ordered till late July.
I think I have a few older PICs floating around somewhere so maybe I can use 2 smaller chips and get the full functionality.

So, i know your trying to avoid tearing apart the saturn controller, but wouldnt it have just been easier at this point? lol i dunno, gl with the microcontroller route

Where's the fun in that?

Are you serious? Tearing apart the Saturn controller was the easier solution at EVERY point.

The point isn't to get a controller that feels like a Sega Saturn controller working on the 360 it's to get an ACTUAL Sega Saturn controller working on the 360, as soon as you gut it it's no longer a Saturn controller it's just a hunk of plastic and buttons that look like one.

Besides I really have no intention of using this very often, I'm doing this to show that it can be done, and it's fun to lean how this stuff works and go through iterations of a design.

I've done a lot of very interesting mod projects but I rarely get it right on the first try. I'm not an EE I teach myself all this stuff. Though my first attempt didn't work I've learned a lot about multiplexers. Now I'm sure I'll learn a few more things about PIC chips once that equipment comes in.

If I have the option of doing something one way that will give me more flexibility in the end product or another way that that will just get it done easily, I'd rather choose the right way then the easy way.

im not gonna lie, you guys are way to smart. Honestly, in order to understand everything that has been mentioned in the last few posts, id have to look up like every other word... so confusing. sooooooo confusing. Its like trying read chinese... it just doesnt work. lol

Anyways, my head hurts and i really dont know your status right now, but hopefully its coming along and hopefully it will turn out amazing and youll be all cool and awesome and YAY!

...Just thought id throw some encouragment in there!

hahaha

Hi again,

well, I haven't worked much with PICs lately. But honestly, all you need to look at is the number of I/O. If you can get an internal oscillator I guess that is a plus since that would eliminate the need of an external one. Programming it should be a breeze for you, it's not very advanced. Unfortunately the high pincount drives up the price a bit on microcontrollers. If I would have done it myself I would have gone for the atmega48 for about $2.7, it has 23 I/O. But PIC is easier to work with if you want to program it in C

I think this will be a nice and quite easy mod to do.

/pablot

I went with the PIC because I'd used them before and I know C better then any other language (despite the fact I haven't used it in years )

The chip I got has a clock as well as some A/D converters (if I decide to do analog stuff).

What would be the benifit to using the clock as opposed to just some infinitely looping code?

something like this:

the atmega8 also has A/Ds.. =)

anyway, the clock I'm talking about is the oscillator.. You'll need one of those to make the mcu run, but I think you know that only that I confused you =)

The pseudo code looks allright. I would do something like this:


something like that.. My C coding is also a bit dusty =)

/pablot

yeah obviously I'd have outputs at ever step

Though I'm sure it'd be just as happy calculating everything without the outputs

hehe, yah.. MCUs hardly ever complain.. I have had a case or two where they got so angry that they started to smoke, but that was mainly because of some idiot (yeah, that would be me) connecting ground and power bad..

/pablot

I remember I took a microcontroller course at school and the very first day the professor said:

I've had a few cases where I let the smoke out...

hahaha.. man.. that was a good one =)

i bookmarked this, will hope you get some nice stuff working, would be great to have a small PCB where we can connect the different wire from each past-gen controller, i did something like this for the original xbox(se link in sig)

greetings

holy crap dude... I've got 2 words for you: Wire Management

This mod is pretty much the same thing but for the Xbox 360 and converting a Saturn controller as opposed to an Amiga or some generic connector.

Also get rid of that angelfire page.... for $10 a YEAR you can a real host.

Not the best in the world but it sure beats any of those crappy free hosting sites.

I got the PIC chip and programmer in today.

I probably wont have much time to work it today or tomorrow, thursday night and defnitly this weekend though.

Awsome job guy, keep up the great work. I wont even being to think about how all this is done

OK so I went to work on this last night and my desktop wouldn't boot into windows... something about registry corruption. So rather then dealing with the headache right there I decided to just play my 360.

I installed Windows XP MCE 2005 around the time I got my 360 and it's given me nothing but headaches since I put it on... So it looks like tomorrow will be spent rebuilding my machine, I'll probably go back to regular old XP as I never used the MCE crap at all.

In the mean time I started looking at the code I could use to do this... The kit came with "lessons" but they're just pre-written projects, all of them however are written in assembly. The code environment has a tutorial with it's documentation too but it's written for use with the 18F722 (also in assembly).

Digging around my office I found a PIC programing book, but all of it is written in Basic for the 16F84 chip..

I know NOTHING of assembly language. What I really need to know is
-what version of C I should be using with my chip (C17, C18 etc.)
-how to setup the IO ports on my specific chip in C and or if there are specific files I should be including with my code.
-how to read and write from the IO ports for my chip in C

I can find this stuff for other chips but it differs enough per chip that it's useless without knowing the stuff for my specific chip;

When I DO find stuff for my chip it's all in assembly and I have no idea what's going on

Anyone who can point me to some good reference material for working with the PIC16F690 in C it would be greatly appreciated.

oh you bum!! Read the data sheet

nah, but if you need some help just contact me on aim, icq or msn and I'll try and help you out!

/pablot

okay, so the pic16f690 aren't very c-friendly it seems..
this compiler supports it though:
http://www.sourceboost.com/Products/BoostC/Overview.html

just throwing in my two pence (or cents or whatever), but is what you're trying to do similar to this:

http://www.lik-sang.com/info.php?category=...oducts_id=3707&

it's a converter to use playstation pads on the neogeo. the pad output signals are converted to work like regular on/off switches. shame they don't have a saturn one though, and it'll probably only handle directions, 4 buttons and start, but i'm talking about the idea behind it.

i'd like to see how this works out for you, and thanks to HSF2 being delayed further you've got plenty of time

wonder if they'll bring out a 360 magicbox in the meantime?

OK so I got the PC all up and running again...

Seeing as how C unfriendly both my assembler and my chip is I've decided to just bite the bullet and do the whole thing in Assembly.

And since I don't know assembly AT ALL I picked up a book today ("PIC in Practice" by DW Smith)... I'm already through the first two chapters. This will delay the project a bit but I'm doing this more as a learning experience then anything else, and I've always wanted to learn assembly. It requires a whole lot more thinking then writing something in C or Basic, but it's pretty simple overall (the language is simple but using it is difficult, how would you talk to someone if your entire vocabulary was only 35 words?).

One other interesting tidbit... it would seem that the internal signaling MS uses in the controller's isn't a simply logic high, logic low per button. Instead they have some funky button matrix they use with an actual data stream being turned on and off per button (nothing like making things complex for no good reason) so it looks like my outputs will have to control switches... I'm not sure if I'll be able to get away with transistors so I might have to go with some solid state relays.

oh and billy_dimashq, yeah what I'm doing is very similar to that... but with a Saturn controller and more stuff after the output has been converted to the "on off switches"

hm.. you shouldn't have to do that actually.. you want to imitate the buttons, and the buttons are just pressed by you with your fingers, so you shouldn't have to care about the funky stuff ms does to interpret the button presses. Or am I missing something?

Now see.. now that you are swithching to assembly you are really going to regret not going for the atmega88 and its 131 "powerful" instructions. And most of all you are gonna hate the bankswitching of the PIC, at least I do.

If you need some pointers to assembly you know where to find me.

/pablot

duh.. yeah, now I get what you mean with the matrix, and yeah, it won't be that easy then. What I would do is use some three state buffers to do it.. relays seem overkill. Or maybe a transmission gate? not sure how good that would work though..

Bummer with the matrix.. MS has chosen many solutions like this on the 360 so keep the pincount as low as possible. On the ring of light they use a pwm system with some inverters to bring the pin count of the 8 leds down to 5 pins, quite smart and easy to work with if you are sitting on the chip that is generating the PWM signal. For the fader360 I had to tap on the the 50Hz PWM and synch up to it, damn MS for making our life harder...

I think I have some tri-state buffers laying around from another project... they're Surface mount though and I really hate working with that stuff.

we'll see, I plan on trying transistors out first and if that doesn't work I'll give the solidstate relays and tri-state buffers a go.

Sounds good.

can i ask the question y would u want to change a great xbox controller to the not so great sega saturn controller i just don't get it