How To Build Your Own (8 Way) D-pad...


bacteria

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Challenge - how to make your own D-pad - :)

A D-pad with only 4 directions is in fact able to play games on the GP2x as 8 way. The doubters were adamant that Vektar wouldn't work - wrong - works perfectly. First game I played on it I got 78,000 points with my D-pad - is this good for a first play? You don't need a special chip, etc.

People are seemingly having lots of issues with the stock stick, especially as moving the stick to the left direction seems to get more problematic as the stick gets more and more use.

I thought, rather than keeping my project purely to myself (after I got seriously annoyed by a lot of post replies from people who could only demonstrate their loutishness and ability to be destructive rather than be constructive :( :angry: ), I would set you all a challenge - make your own, and use this topic to post your updates and pics (I won't post my pics yet as I want to see how you get on). :rolleyes:

To all you doubters, I can confirm that my D-pad project has progressed nicely, the design has changed dramatically, the unit is quite robust now, and it plays all game beautifully I have thrown at it, including diagonals (I haven't tested all games of course, just the couple of hundred of games (inc homebrew) I wanted to play).

Naturally, you will have to open your GP2x to do any modifications to it. If you were intending to modify your unit with another product then you will have the confidence to do this anyway. Naturally, you run the risk of invalidating your guarantee by opening your case and playing with the insides, you are responsible for your own actions and any damage you might cause by any means, your choice and risk, usual covenants apply, I am not liable or responsible in any way for anything you do or attempt to do, etc. As you know, this all also applies to firmware updates! I am only reporting on what worked for me - make a judgement and take your own educated risks.

I can confirm that the connectors at the back of the stock joystick appear to do everything you need - connections for the push button and the 8 directions. You do not need any special chips or electronics for this mod (unless you want to waste your money of course). You also don't have to do any drilling of your case or even remove the stock stick (see below).

The beauty of this mod is that if you don't like the result, you won't have damaged your GP2x case (unless you are careless or han-handed), nor removed/cut out the joystick; and by removing the solder from the joints from the wires for this mod, your GP2x is back where it started from.


Connection of the wires: <_<

Looking at the joystick connections (top right on the GP2x motherboard, when you remove the 4 screws and open the case)

diag.jpg


C & I seem to do the same thing and only one is required, so I use "I" (try using "C" if you prefer).

A+I = up
D+I = left
G+I = down
J+I = right
F+L = centre push

Considerations for your build: :blink:

i) Use the thinnest (insulated) wires you can get - ones from an old (and no longer required) joystick/gamepad/scart cable ideal. They need to be thin, you need to get 7 wires though the front of the GP2x in the joystick hole. Use quality solder - 60/40% standard electrical solder is fine.

ii) If you use an existing D-pad from a games controller (eg Nintendo one, or whatever), you have the problem of drilling a hole in the GP2x case and ruining it, and also supporting a flat circuit board in the right position, reliably (and removing the stock joystick unit completely). Not a good idea in practice. Best to make an external D-pad - you need to make one yourself (which is what I did). This means making a solid base, and a top which completes the contacts.

iii) An external D-pad assembly has to fit over the place the existing joystick is based (wires connecting from the D-pad, round to the back of the motherboard by the left shoulder button (you can see the recess in the picture above), soldered to the corresponding contacts as shown above). The external D-pad needs to be secure on the Gp2x so it doesn't move, yet able to be removed if you want to (so don't use glue!).

iv) You need to mount a basic switch for the centre push button - you must have a centre push, as most emulators and games on the GP2x use it to exit to menu or during the game itself. This is ideally situated next to, but not on the D-pad, as otherwise it makes assembly more difficult, and gets in the way anyway.

v) A switch is only two contacts separated, when pressed together make a contact. This can be done my many methods, including using metal and foam pads, rubber, whatever - depends how flat you want them. Flatter final product, the better. You need to make 5 switches in total (directions and push). The contacts separating the D-pad can be made in a large variety of ways.

vi) Don't laugh, or go "WTF"; but you can make a reliable D-pad with: sticky foam pads, mounting board, self-adhesive floor tiles, tin foil, staples, adhesive labels, foam, tissue paper and glue. Household items. Might sound rubbish, but with this you can make a cheap, sturdy and reliable unit, and a basic circuit board (if you want to make a flat and good job of it), which you will need to do. It looks quite good too as a final product, and is easy to modify if you need to for any further improvements. Don't laugh - experiment - my unit works perfectly, and is reliable, and quite good looking. You are only restricted my your ability.

vii) Test your completed product's circuits all work fine by connecting a battery to a light, touch the 2 corresponding wires of your D-pad to these wires (ie one of the wires from the battery/light to the wire you intend to solder to "A" and the other one to "I" to complete the circuit - press the D-pad in the "up" direction, and if the light works, test the other contacts - when all work, think about attaching it to the GP2x. If you haven't made a unit which responds to up/down/left/right/push, don't install it in the GP2x - you can test the unit easily by this proceedure.

viii) D-pad needs to be elevated above the stock joystick as you don't want the joystick to move at all - the D-pad needs to be above the stick, the only relevance the old joystick has is that you are using its connections at its rear.

ix) Make the unit to be strong, but also as flat as possible. You can adjust how responsive you like the D-pad to be by the materials you use. Mine is very responsive - as I like it.

Challenge: :ph34r:

Make your unit. Should only cost you pennies to make it (but a fair bit of time). Post pics and comments as well as your WIP.

I will be interested to see how many of you are creative enough to do this, and what your final unit looks like. When others have posted their pics, I will post mine. Could be fun, and productive.

It is a shame that people flamed me so much abuse on my previous D-pad topic, there are many hostile and childish people on this Forum.

I figured:
* show you how to make your own D-pad unit in a way which doesn't need major work on the GP2x (and backward compatible)
* let you experiment with making one which looks nice and is reliable
* post your pics and get praise and comments
* see who can make the best unit
* make a good project for people
* provide a way to test the D-pad before even opening your GP2x case - nothing ventured, nothing gained
* gives me a chance to give a positive contribution to the community
* either people will make their own D-pad (great), or if I decided to sell mine (probably won't, will see how it goes) - 1) people won't steal my work (as I have given away the principles of it here anyway), 2) people will hopefully realise how great this system works and will stop making comments to the contrary. As the saying goes, "proof is in the pudding".
* I have a good working unit - will be interested to hear how you get on
 
Thanks for your inspiring post! :)

The D-Pad is my main gripe about the GP2x, it really spoils the experience.
You've obviously spent alot of time researching this. I myself am not too confident about soldering, but if I have time (and bravery) I'll give it a shot and post a WIP :unsure:

Ideally I would want to replicate the Dreamcast D-Pad - my personal favourite.
 
gothakane posted on Apr 2 2006 at 12:35 AM said:
Thanks for your inspiring post! :)

The D-Pad is my main gripe about the GP2x, it really spoils the experience.
You've obviously spent alot of time researching this. I myself am not too confident about soldering, but if I have time (and bravery) I'll give it a shot and post a WIP :unsure:

Ideally I would want to replicate the Dreamcast D-Pad - my personal favourite.


Thanks for your positive comments. Yes, I have spent a lot of time researching this and making prototypes. I got the wiring details from finding a .pdf of the joystick itself, which showed what connected to what.

The soldering is easy - normally, soldering requires delicate and precise work - fortunately, the pins stick out of the motherboard by about 3mm, so they are very easy to solder too. My soldering skills are not good either, and I have had to solder and desolder and resolder many times (with each prototype I tried). There is no need to do any soldering for the D-pad itself - use glue and staples and the sticky-backed materials!

Good luck with the project. You can replicate whatever you want that works for you.
 
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Addendum - if anyone needs more information on the build, please ask and I will do what I can to answer them. I have kept further details away at this stage, to give people the chance to come up with their own solutions to the problem - they might come up with a fantastic solution that way, rather than just being steered into my solution method. Evolution!

Good luck!
 
Wow, thanks for the diagram :) I would definately attempt to make this since I'm an experienced solderer. But, I would rather not drill a hole to put in my D-pad, and nor would I be good at making a D-pad myself. My question to you is if you can possibly solder the following with ribbon cable together in your diagram:

A+I = up
D+I = left
G+I = down
J+I = right
F+L = centre push

(for instance one end of the ribbon cable would attatch to letter A while the other attatches to letter I)

If I'm correct, if you wanted to use the original stock stick you could, but it would just work like a D-pad. Am I correct with this bacteria? Because I'm pretty tempted to do this :)
 
Im sorry if this has been covered, but i couldnt find it:

Are there any specific games that do not work without independant diagonals?
Also, what kind of response do you get in the gp2x test screen? does it register a diagonal, or just the X and Y?

(feel free to point me in the direction of a thread if this has already been covered, which im sure it has).
 
grahf posted on Apr 2 2006 at 03:57 AM said:
Im sorry if this has been covered, but i couldnt find it:

Are there any specific games that do not work without independant diagonals?
Also, what kind of response do you get in the gp2x test screen? does it register a diagonal, or just the X and Y?

(feel free to point me in the direction of a thread if this has already been covered, which im sure it has).


The test screen just tests switches nothing more, nothing less. So with this mod you will only get an x,y reading as those are the only switches making a connection. It is up to the application to interpret an X+Y contact as a diagonal. Old systems like NES etc would only show X,Y in a switch test program as they all only had X,Y connections as well. It all comes down to how the app is coded. Many will work, some will not.
 
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minkster posted on Apr 2 2006 at 02:37 AM said:
Wow, thanks for the diagram :) I would definately attempt to make this since I'm an experienced solderer. But, I would rather not drill a hole to put in my D-pad, and nor would I be good at making a D-pad myself. My question to you is if you can possibly solder the following with ribbon cable together in your diagram:

A+I = up
D+I = left
G+I = down
J+I = right
F+L = centre push

(for instance one end of the ribbon cable would attatch to letter A while the other attatches to letter I)

If I'm correct, if you wanted to use the original stock stick you could, but it would just work like a D-pad. Am I correct with this bacteria? Because I'm pretty tempted to do this :)

You don't need to drill a hole in a D-pad - you are making one from scratch, remember! You can't use a commercial D-pad as they are pcb and hard to mount. I used a ring binder hold-punch to cut holes in the card (to stop the stock joystick from coming into contact with the D-pad), and a drill to bore a hole into a piece of floor tile (hole cut to go around the raised circle where the joystick surround it (this holds the unit firmly to the Gp2x and allows removal if required...). Keep it simple!

The wires have to be separate wires, as otherwise you can't feed 7 wires through where the old joystick hole is. A ribbon cable might work, but separate the wires first (and colour code them so you know what goes with what!)

There is a lot of confusion about the joystick/D-pad business <_< . The connections to the back of the joystick itself allows all movements - the 4 directions, the diagonals (which we don't need as the 4 way makes diagonals), centre push. We don't want to use the joystick itself, only its connections (bypassing moving the stick at all). The point is to make a D-pad raised above the old joystick, so you don't accidently catch it, (ie the joystick stick DOES NOT MOVE), when you move the D-pad, it triggers the connections on the back of the joystick fooling it into thinking that you did use the joystick (which you aren't). The point of this is that you can have very accurate movements from your D-pad, ie left is left, etc.

Crude diagram

top.jpg


A - D-pad
B - gap to stop any movement from joystick while you use the D-pad!
C - joystick stick (sticking out of the GP2x a bit) - illustration
D - that lousy stock joystick!
E - the connecting pins for soldering (pertrude from the back of the motherboard)
F - motherboard inside Gp2x

My unit is designed with (about) 85 degrees tolerance with each of the up/down/left/right movements and something like about 20 degrees (in practice, not mathematically) for diagonals. Make yours as you want to. Works great.

Make a unit and test it with an old battery and a light, as illustrated in my post. If you can't make a good unit, you haven't had to open your GP2x, all you have lost is time. Nothing to lose this way!! ;)
 
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grahf posted on Apr 2 2006 at 03:57 AM said:
Im sorry if this has been covered, but i couldnt find it:

Are there any specific games that do not work without independant diagonals?
Also, what kind of response do you get in the gp2x test screen? does it register a diagonal, or just the X and Y?

(feel free to point me in the direction of a thread if this has already been covered, which im sure it has).

Haven't played any games that don't work on this yet. Probably the only possible game is Whacky as that is looking for a specific diagonal key as opposed to up+left=diagonal. I believe the author said (he) would modify their program to allow this. Everything else you throw at it should work, including Vektar, DrMD, MAME, etc, etc.

If it is so really important to have a completely dedicated diagonal (which it isn't) you can use pins B, E, H, K on my post, which are for diagonals. I repeat however, you only need 4 way to behave as 8 way.

Make your own D-pad unit. Any doubts you have about this working (with diagonals in games) will vanish. B)
 
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bacteria posted on Apr 2 2006 at 01:04 AM said:
vi) Don't laugh, or go "WTF"; but you can make a reliable D-pad with: sticky foam pads, mounting board, self-adhesive floor tiles, tin foil, staples, adhesive labels, foam, tissue paper and glue. Household items. Might sound rubbish, but with this you can make a cheap, sturdy and reliable unit, and a basic circuit board (if you want to make a flat and good job of it), which you will need to do. It looks quite good too as a final product, and is easy to modify if you need to for any further improvements. Don't laugh - experiment - my unit works perfectly, and is reliable, and quite good looking. You are only restricted my your ability.

I wouldn't mind some more details on how you did this. Obviously it's not too hard to make four functioning switches out of a bit of foil, sponge, glue, etc, but I doubt that I'd be able to make one that was sturdy enough to actually play with.

Have you got any photos of the pad you assembled?
 
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bacteria posted on Apr 2 2006 at 09:12 AM said:
Make your own D-pad unit. Any doubts you have about this working (with diagonals in games) will vanish. B)
I'm sure that's true, but I still don't really like the idea of leaving 4 unused connections in my device. It's like buying a porche, noticing that it can do 80 mph in 3rd gear and disabling gears 4-6 just to get a more comfortable gear stick. 99% of the time you don't need the extra gears, but why get rid of them when it's so easy to keep them?

I guess I'm a perfectionist.
 
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DaveC - Experiment, make one. You will realise "Many will work, some will not" is actually "Almost everything works, very little if any don't". Theorising is fine, this is a practical solution to everyone's problem!

People can make their own D-pad, with a little experimentation and a few hours to kill, for virtually no cost. The only people I expect to now put post replies saying "it can't work because of diagonals", etc are the people who can't make one themselves and would rather slate an idea (I have no time for these individuals). Make one and try it out.

If they can't make one, no issues (I can assist with advice); if they can't make one which works, they won't have opened the Gp2x, no issues; if they make a working model and install it, they will love what they see and the unit will look as good as their imaginations and skill allow. The alternative is to stay with a stock joystick (even with the best cap design available) with a mind of its own, frequently uncontrollable, and becomes stiff and unresponsive with use.

I am expecting some people to make good working units. Many people may not be able to (or have the time to). I will monitor this thread closely to see how people get on, and will help them with advice on making a D-pad work (for free). I might offer to sell my units to those people who can't make their own (just like you did DaveC !), but would earge people to experiment to make their own, and report back with their findings.
 

I wouldn't mind some more details on how you did this. Obviously it's not too hard to make four functioning switches out of a bit of foil, sponge, glue, etc, but I doubt that I'd be able to make one that was sturdy enough to actually play with.

Have you got any photos of the pad you assembled?
[/quote]

Yes, you can make a sturdy one. Mounting board is very sturdy (you only need a 20mm circle cut out for the D-pad top. By the time you make the unit, and hide the circuitry/wires, you may have 2 layers of it anyway. Mounting board and floor tiles have a small amount of "give", but for a unit this small, you will find the materials to be rigid, tough and easily cut by scissors.

Yes, I have pics, but I want other people to experiment and evolve this idea, rather than having lots of "clones". Someone may have a better method than I came up with after all. ;)
 
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FluffyPanda posted on Apr 2 2006 at 08:22 AM said:
bacteria posted on Apr 2 2006 at 09:12 AM said:
Make your own D-pad unit. Any doubts you have about this working (with diagonals in games) will vanish.  B)
I'm sure that's true, but I still don't really like the idea of leaving 4 unused connections in my device. It's like buying a porche, noticing that it can do 80 mph in 3rd gear and disabling gears 4-6 just to get a more comfortable gear stick. 99% of the time you don't need the extra gears, but why get rid of them when it's so easy to keep them?

I guess I'm a perfectionist.

No FluffyPanda, the analagy is actually using a sledgehammer to crack a nut rather than using a nutcracker :p . If your car is falling off a cliff, it doesn't matter what gear you use, the result will be the same B) . You can make your D-pad with all wires connected if you want to, but will make the build harder; and anyway, you don't need to - 4 way=8 way in practice, so your games behave the same way anyway! (experiment!).

Go on, make one!! :lol:
 
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bacteria posted on Apr 2 2006 at 09:37 AM said:
No FluffyPanda, the analagy is actually using a sledgehammer to crack a nut rather than using a nutcracker
I prefer to think of it as a better (though compatible!) nutcracker. But I take your point.
 
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FluffyPanda posted on Apr 2 2006 at 08:40 AM said:
bacteria posted on Apr 2 2006 at 09:37 AM said:
No FluffyPanda, the analagy is actually using a sledgehammer to crack a nut rather than using a nutcracker
I prefer to think of it as a better (though compatible!) nutcracker. But I take your point.

:lol:
 
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Just out of interest, at this point in time, there have been 350 reads of this topic, it would be great to hear from you guys as to who is going to have a go at making their own D-pad. Do you need any more clues as to how to make one??

If people share their findings and WIP, we could really get a good topic of discussion going here, with ideas going back and forth.
 
Now it is so simple I am going to hook up an adaptor plug and have that available to plug in my Commodore Vic20 and Atari 2600 Joysticks for authentic crap control and blisters. (remember those) :D

I was waiting for USB to add pads but as I want to play it mostly on TV a small adaptor out will do just as well as the TV out is so awkward to use.

Might add an old D pad as well - we will see.

Cheers.
 
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