Making A Genesis Pad Work On A Gamecube/Wii

[DuD]

Before I start bothering you all, I'd like to say hello to everyone.

I've been reading the vast amounts of information available on this site, and have got the impression that i could gut a cheap gamecube controller in order to create a genesis/md to gamecube adapter allowing me to play Capcom vs snk 2 on a decent pad.
I've since read that genesis 6 button pads have quite complex circuits, so my question is:
Is this project possible for a beginer? and if so could you give me some advice please?

At the moment i've understood that i would have to link the outputs from the genesis pad to the input of the gamecube chip's corresponding button. so say i wanted the genesis 'Z' button mapped to the gamecubes 'L' i would link the output for 'Z' on the sega chip to the input for 'L' on the nintendo chip. I would then continue the process for the rest of the buttons, then neaten the job with parallel ports and a casing?
Is this correct or am i peeing into the wind here???

The bit thats confusing me is that on the genesis' pin out i've seen, taking pin 3 as an example: The signal given could represent any one of the following: low logic (i assume this is nothing), 'dpad left' or 'X'.
So for pin 3, if i wanted genesis 'X' on cube 'Y' and 'dpad left' on 'dpad left', would i attach genesis output pin 3 to both cube input 'dpad left' and 'Y' ??

Sorry for such a long post, hope it's clear in what i'm trying to say.
Thank you for any help. I look forward to being able to help others as i gain confidence. 

[NFG]

The thing you've got to remember is you'll be bypassing the Genesis/MD encoder entirely, running a wire from each MD button directly to the GC encoder chip.  You'll no longer b e using the MD chip, cable or connector, so its pinout is irrelevent.

If you wanted to poll the MD pad, retrieve and convert the button-press data and then feed that to the GC chip, then yes, you would need to be aware of the MD's connector and encoder, but I'm thinking this is not what you had in mind.

[Blaine]

It'd probably be a little... tricky.
You'd be wiring at least 12 buttons (up, down, left, right, start, select, a, b, c, x, y, z) to a GC encoder chip.

I've prepared a document basically outlining a similar procedure. In this case converting a Sega Saturn controler to USB.

http://www.gamesx.com/controldata/usbsatpad/index.shtml

Have a look. Read it over. It's essentially what you'd be doing.

[NFG]

I've prepared a document basically outlining a similar procedure. In this case converting a Sega Saturn controler to USB.

http://www.gamesx.com/controldata/usbsatpad/index.shtml

Wait, you've prepared what?  Didn't I write that? 

[Blaine]

I've prepared a document basically outlining a similar procedure. In this case converting a Sega Saturn controler to USB.

http://www.gamesx.com/controldata/usbsatpad/index.shtml

Wait, you've prepared what?  Didn't I write that? 

ha ha ha... ahh we kid.
It was a team effort. You did all the writing, modding and so forth and I did the google machine.

[DuD]

Cheers for the help guys.

Lawrence, you were right. I was only looking at re-routing the signals, just over complicated things in my head.
That ?? joint effort ?? saturn to usb guide is perfect for what i was thinking of doing. Especially as i was planning on doing this mod next, ready for PC street fighter IV.

Ive searched the internet for the elecom usb pad and found this: Elecom JC-U2510T. I think this should be ok for the USB mod, however can't seem to find any for sale 
Will keep looking and post alternatives (for anyone else looking at the USB Saturn pad) as i find them.

Ive decided to now leave my Genesis pad alone, as i actually still have my mega drive, and instead wait for the saturn pad and simply create adapters for both GC and USB rather than make the pad work soley on one console.

Thanks again guys. 

:EDIT:

I was wondering if anyone could recommend where i could find a 13 wire cable, or would it be just as good (strong and tidy) if i made my own using 13 individual wires and some sleeving??

Also, I haven't managed to find any cheap usb pads with similar button setups to the saturn pad, but i've found loads with the same number of buttons through simple ebay searching. So no model numbers, but there are plenty knocking about.

Again, Lawrence and Blaine, Cheers.

[Blaine]

A MIDI cable is 13 pins. That's not my area of expertise so, I don't know where you can get them cheap. Googling says somewhere in the $15 range. The connectors are probably something you'd be able to buy.

That said... other cable options.

13 is pretty close to 15 which would put you in VGA cable range.

Pro:
-You can get those for dirt cheap at monoprice.com ($4)
-You can get the 15-pin hdsub anywhere.

Cons:
-15 pin hdsubs SUCK to solder to. I used those as my generic video cable in the past and they're a bitch, a lot of pins in a little space.


Slightly more pins would be the 21 pin SCART video cable (which I'm now using for my generic video cable).

Pro:
-Much easier to solder wires to.

Cons:
-I can't find them anywhere since I live in the US.

Next up would be 25 pin Parallel cables for printers, but we're almost at twice what you wanted.

So of those three you have cheap, easy and ubiquitous... although not all three for one.

[NFG]

MIDI cables are actually 5 pins, not 13.  Dunno what kind of cable you've got...

My favourite cable is a PC joystick extension cable.  15 pins, soft rubber, very moddable.  Dunno if you can find a decent source for them, I used to buy mine in akihabara.

Parallel cables are awesome as well, I use those a lot.  They can be very cheap.

SCART cables rarely have 21 wires inside, you'd be lucky if it had 15, and in most cases, even fewer (RGB, G, Sync, AudR, AudL, Vcc are all that are strictly necessary)

VGA cables often have really thick wires for RGB, which makes them a bit annoying to repurpose.

[Blaine]

After googling for a while, apparently I have a Roland cable.

http://img3.musiciansfriend.com/dbase/pics/products/1/5/3/376153.jpg

I always just assumed it was a MIDI cable... I've inherited boxes of stuff from my sisters ex-boyfriend, I don't know what most of it is.

[DuD]

I've nearly got all parts / equipment i'll need, so i should be able to get the project underway sometime soon.

I'm gonna try and hopefully get some pictures up as i go if i can get my hands on a digital camera.

[duo_r]

have you seen this website?

http://www.raphnet.net/electronique/x2wii/index_en.php

[DuD]

^ Thats quite an ambitious project, whereas i'm just 'nicking' the encoder chips from existing pads.

I was hoping that Lawrence could shed some light on his comment: "VGA cables often have really thick wires for RGB, which makes them a bit annoying to repurpose.", because i was looking at using a VGA cable as (as Blaine said) they are cheap and ive managed to find some 15 pin d sub connectors.
Will i find it hard to solder the thicker wires to the pcb / chip? or will it just not be possible??

I have managed to find some 21 pin scart cables on ebay (if they've got 21 pins they should have 21 cables shouldn't they?), so would it be better to pick up a scart cable and wire that to the d sub connectors? or just use a VGA cable??

[duo_r]

how many wires does the genesis cable have?  It's like 9 right? Is one of those lines ground? If so you could use a 8 din cable and bypas the cable to the sheild connector.

Otherwise if you need all 9, you could go with a DVI computer cable. I used one and it hand plenty of lines. It was a little thicker, but not bad at all:

[DuD]

I need a 13 wire cable, so that i have a wire for every button on the saturn pad.

What i'm doing is taking the outputs from the buttons on the saturn pad (the inputs to the saturn encoder chip) and connecting them directly to the inputs on the gamecube (and PC) encoder chips.

[ken_cinder]

I'd use a Parallel cable in that case, Parallel printer cables are a dime a dozen here at thrift stores etc and easily found at garage sales.

[DuD]

I had a look at parallel cables, but i'm gonna be left with 10+ unused wires. wouldn't this end up looking pretty messy??
Though you sound like you have more experience than me so i'll just take your advise.

For another problem, I've had my gamecube remote (its a logic 3) come today, and having opened it up i couldn't find any thing that looks like a chip. Having inspected the pcb, i've found that alot of the tracks head to a small (ive seen bigger resisters) circular black thing that is surrounded with some black stuff. i take it that this is the chip and its coated with resin or something???
If this is the case, i won't be able to remove the black stuff will i? and so can't solder directly to the chip?

Instead, i thought i could solder to the pads on the pcb (the ones underneath the buttons). is this feasable? if so, how would i go about doing this? would i need to do anything prep wise to the metal pads or could i just solder wires directly to them from the saturn pad?

If photos of the circuit board would help understand any of this, let me know, and i'll get some online.

Many thanks for any help.

[duo_r]

the cable I referred you to (DVI) has more than enough data lines, it isn' harmful to not use all the lines. And if yo look at the pic I showed you it isn't that thick. Have you ever thought of building the encoder internally tho? Then you could just have like 4 (maybe it is 5) data lines going to the Gamecube port. If you check that link I showed you it shows you how with the use of their PCB.

But anyways, DVI can be expensive to buy, but I got mine for free at work since our IT equipment comes with DVI cables (when we get a new Monitor) but since we use VGA it is no cost so I use these for my mods.

Parallel is just too thick IMO, unless they are making those thinner these days.

[DuD]

Just another thought to add to my previous post.
If i end up soldering to the metal pads on the gamecube pcb, i'm also going to need to send a ground wire to the saturn pad aren't i ? in order to make the buttons on the saturn pad work.
I am right in thinking the gamecube chip will have the pins for the buttons held high, then when a button is pressed the corresponding pin will go low??
i.e: If the button has two halves (1 going to the gamecube chip and the other to ground) and when the button is pressed the two halves are connected, connecting then gc chip's pin to ground.

[ken_cinder]

I've never seen a pad without a common ground (Usually easily seen running all around the PCB, quite wide in some areas).
All you should need to do, is wire ground somewhere on the PCB that leads to everywhere else, and you're good.

I hacked a Playstation pad for my MAME cabinet when I first set it up and was waiting on my other parts, I wired 1 ground to the R1 ground point, and that was all I needed.

[duo_r]

there are some Xbox 360 pads that don't have common ground. I prefer to use the common ground setup since that is the easiest to hack for joysticks. Fortunately, I found a 360 pad that DID have common ground.

I've never seen a pad without a common ground (Usually easily seen running all around the PCB, quite wide in some areas).
All you should need to do, is wire ground somewhere on the PCB that leads to everywhere else, and you're good.

I hacked a Playstation pad for my MAME cabinet when I first set it up and was waiting on my other parts, I wired 1 ground to the R1 ground point, and that was all I needed.

[l_oliveira]

Any pads with pressure sensor on the buttons will not have common ground because the buttons are actually analog and their output resistance is measured with A/D converters and voltage comparators.

The stock 360 pads are of that kind. So are the PS2/PS3 pads.

[ken_cinder]

Go away! We're talking old school here, he only needs ground at the Genesis pad, which is all common.

Why tear up a 360 pad anyway? Classics on the arcade are best played in there real form!

You guys are just being picky now......

[NFG]

Any pads with pressure sensor on the buttons will not have common ground because the buttons are actually analog and their output resistance is measured with A/D converters and voltage comparators.

The stock 360 pads are of that kind. So are the PS2/PS3 pads.

This is completely incorrect.  Analogue buttons do not require separate grounds, and the stock 360 pads DO have common grounds.  Sometimes.  I have found that all my wireless pads are great for modding, but wired ones are not, because of the common ground issue (see here for details).

[l_oliveira]

This is completely incorrect.  Analogue buttons do not require separate grounds, and the stock 360 pads DO have common grounds.  Sometimes. 

Then I'm not completely incorrect ... lol

Then being told to "Go away!" isn't nice... But I'll take that as humor.   

Now back into the technical stuff, PADs that don't have a common ground for buttons have an sort of "AGND" which is similar to the audio ground you find on some game systems or A/V equipment. It's meant to keep the digital noise generated by the PAD chip itself away from the A/D converters avoiding miss reading of the buttons. It's a sort of common ground indeed but it's separated from the main common ground or "GND".
Also it depends on the design of the pad. Some of the game system makers used to outsource pad design and manufacture so multiple/different designs do exist. Sony is the best example of this.

Now, a lot of oddities do exist.  Do I need to mention how a certain model of SEGA Saturn Joystick (that pad for flight games) have optical proximity sensors for the main joystick axis and throttle button ?

As the legacy systems stop working and suitable replacements appear on the current gen consoles more and more people may be interested on modding the current gen game pads into retro hardware. So I think that this kind of information (how to wire old style pads on new hardware) will be eventually needed.

Now, being a bit less silly and to add to the thread: For the Wii remote and it's peripherals, I dismantled my Wiimote along with the classic controller and took a good look inside. All buttons are digital, so it's easily moddable.

[duo_r]

Thanks Lawrence, like i was saying there is a version of the 360 pad that has common ground (not all of them do). I happened to obtain one and made a wireless arcade joystick out of it, and the buttons share common ground. I do believe tho that the analog trigger buttons (only 2) have their own seperate ground because I had to wire those up seperately. All the other buttons (which are digital) have common ground including D-pad.

Like I said tho, there is another version of the Xbox 360 pad that does not have common ground (I believe this one is referred to the matrix setup).

Any pads with pressure sensor on the buttons will not have common ground because the buttons are actually analog and their output resistance is measured with A/D converters and voltage comparators.

The stock 360 pads are of that kind. So are the PS2/PS3 pads.

This is completely incorrect.  Analogue buttons do not require separate grounds, and the stock 360 pads DO have common grounds.  Sometimes.  I have found that all my wireless pads are great for modding, but wired ones are not, because of the common ground issue (see here for details).

[ken_cinder]

This is completely incorrect.  Analogue buttons do not require separate grounds, and the stock 360 pads DO have common grounds.  Sometimes. 

Then I'm not completely incorrect ... lol

Then being told to "Go away!" isn't nice... But I'll take that as humor.

It was meant as humor, as in stop ruining my childhood memories of simple fun stuff!

[DuD]

I have finally completed my Saturn to Gamecube converter, but have found an unexpected problem 
All my wiring works perfectly, but having tested it in a game (Capcom vs snk 2) i've found that removing the analogue stick has caused directional issues. To try and fix this i have cut the links on the pcb between the pads (under where the stick was) and the chip, however this has not solved the problem.

Can anybody shed some light as to what is happening? does the chip actually require a voltage from the analogue stick to set it neutral??

Thanks for any help

[duo_r]

when the stick is centered, it is sending a certain value to the PCB which tells it is centered. If you remove, it is changing the value, and making the controller thinking it is not centered. You will have to use a resistor to send the correct value that the stick is present and centered. However, did you try the flip switch that selects Analog VS Dpad mode? Maybe that would be an easy fix, just jump the Dpad mode pins.

[DuD]

However, did you try the flip switch that selects Analog VS Dpad mode? Maybe that would be an easy fix, just jump the Dpad mode pins.

I don't think there is a switch that selects Analog vs Dpad on the gamecube controller? unless its an electronic switch triggered by some code in the games.  please let me know if i'm wrong.

[duo_r]

I got confused, I thought you were talking about removed an analog stick from the Saturn controller (assumed the Nights controller). Nevermind that one. But you do need a resistor value on the Gamecube controller.

However, did you try the flip switch that selects Analog VS Dpad mode? Maybe that would be an easy fix, just jump the Dpad mode pins.

I don't think there is a switch that selects Analog vs Dpad on the gamecube controller? unless its an electronic switch triggered by some code in the games.  please let me know if i'm wrong.