Me Doing Bacteria's D-pad Mod

[bacteria]

Ok, got your PM mate.

Been ages since I looked at this old mod of mine, it was my first modding experience and my skills were totally shite in comparison to now.

The joystick is the same for MK1 as MK2, however it was rotated a bit on MK2.

The orange and red wires must be grounding connections, so if you have a multimeter, you can easily find out which is which. You only need to use one of these, not both.

Soldering to joints - best to tin them first (add solder directly to them so solder attaches, if it doesn't want to, use a little flux) before soldering a wire to them. 30w is a good wattage for a soldering iron, 15w might be ok but is not that hot. You seem to have managed to solder ok (!) so that is all that matters. Don't have the bare wires BTW, you are inviting shorts!!

Joystick - you can desolder it, or cut off the pins, or if you externally mount a d-pad (as I did) just clip off the shaft. Another method, brutal, but I use it sometimes, is to use a diamond metal circular cutter on my dremel and cut through the joystick, to get to the pins, cut them right down on the mobo front. You need to be very careful though - especially as you could slice through your fingers if you aren't careful, or end up hacking off other parts of the mobo if you slip. I use this brutal method to normally remove game ports, video ports, and other similar inconveniences - same principle with the GP2x joystick.

This method is a good idea as the traces in the mobo are apparently in the middle of the board.

 

[quadomatic]

I'm in the process of desoldering the joystick right now...its not very easy. My soldering iron doesn't appear to be quite as hot as it needs to be to make this job easy enough, but I suppose I'm better off since this way I won't be inflicting so much heat damage.

I think I damaged the L button too...soldering iron touched it and it melted part of the plastic and the button is stuck. I guess if I apply heat to it again it'll melt the plastic and get the button un-stuck...

 

[jmetal88]

I use an actual desoldering iron to desolder things. I got it at RaidoShack. I think it works a heck of a lot better than desoldering braid. Just squeeze the bulb, put the tip over the pin until the solder melts, then release the bulb and suck up the solder!

 

[CronoTriggerfan]

Wow, did you tin your leads before starting? A thin coat of solder on your wires before soldering them to the board does wonders. Your contact should be more like a slight bulge with the wire stuck flat to the board, not a big ball of solder. That can create a cold solder joint (aka bad joint), which wouldn't complete the circuit. Also, braided wire is far better than solid for small components of this nature, as there's more surface area to cling to after it's all twisted up. Your soldering iron is the perfect wattage for a job like this, but not for removing components. Do you have a desoldering iron, or at least some desoldering braid?

 

[quadomatic]

Wow, did you tin your leads before starting? A thin coat of solder on your wires before soldering them to the board does wonders. Your contact should be more like a slight bulge with the wire stuck flat to the board, not a big ball of solder. That can create a cold solder joint (aka bad joint), which wouldn't complete the circuit. Also, braided wire is far better than solid for small components of this nature, as there's more surface area to cling to after it's all twisted up. Your soldering iron is the perfect wattage for a job like this, but not for removing components. Do you have a desoldering iron, or at least some desoldering braid?

I have desoldering braid. I'm in the process of desoldering it, but its not easy. I got most of the solder off, but maybe about 4 pins still have enough solder that I can't see through the holes.

 

[CronoTriggerfan]

Well, a desoldering iron would be much better. Either way, try heating up the old solder, mixing it with a bit of new solder, and then attempt the removal. Also, throw some flux on it and see if that helps. If you can physically grab the component, you can try heating up the solder and wiggling the pin until it comes loose, but that's better suited for 1 or 2 pins, not 4.

 

[Chip]

I highly recommend you invest in a solder sucker. They're cheap and very handy with this sort of work.

 

[senquack]

I highly recommend you invest in a solder sucker. They're cheap and very handy with this sort of work.



And get the bigger one like the one Chip linked to (12" or longer) not the mini ones. The mini ones are worthless.

 

[quadomatic]

I bought a desoldering bulb today, which is like the solder sucker I guess...but its a bulb, instead of spring loaded. I haven't really tried desoldering it yet today.

 

[jmetal88]

Radioshack also has a spring loaded desoldering tool, but the desoldering iron really works much better.

 

[CronoTriggerfan]

I own both, and in my experience, desoldering tools are better for working with large solder joints like the ones you find in arcade machines and JAMMA boards, whereas desoldering irons/bulbs are better suited to smaller joints and component detatchment. Either way, good luck with getting that stick loose!

 

[quadomatic]

After trying to get the pins desoldered for a while, it seemed impossible to actually desolder them. I went back to trying to clip the pins with a nail clipper; this time I was actually successful.

With the assembly removed, I soldered wires back onto the pads, and gave it another shot...yet again, I was unsuccessful.

But, when testing, I took the red/orange wire and poked it into the assembly hoping I would hit one of the assembly pads. I was able to get a hit that registered to the right. So, I have a feeling that the diagram I'm using for soldering wires to which points is incorrect.

I was trying to make a battery pack that I could strap to the GP2X while the back of the case is off so I can poke the red wire at stuff and find which pins are for which, but my batteries ran out of power (and I managed to short some stuff along the way causing the GP2X to restart).

The diagram in Bacteria's PDF was made for a MK1. Does anyone have a diagram for a MK2?

 

[bacteria]

You can easily find the contact points by using a multimeter - one terminal on ground connection, one on a direction pin, press d-pad, then you can work out what is what.

 

[quadomatic]

You can easily find the contact points by using a multimeter - one terminal on ground connection, one on a direction pin, press d-pad, then you can work out what is what.

Press D-pad? I'm not sure what you mean...am I missing something? What I was doing was connection the ground pin to directional pin. Isn't that what I was supposed to be doing?

UPDATE: So I finally got up the nerve/time to figure out which pins were the ones that were the proper ones to solder to...apparently the correct pins were every one I hadn't soldered to (of course). In fact, the pins that were for left right up and down, were the pins that were on the left side, right side, top, and bottom.

Also, I think I'll actually be okay for the soldering. I understand what you all meant by the traces being 'in' the motherboard. There are little metal rings surrounding the holes, which need to have contact for the press to register. I suppose I could just bend the wires into little loops, stick them in so that they touch the sides properly, and then solder them in. 2 of the holes actually still have the pins in them, so that should help.

I suppose I should also be grateful that the point I used for the ground wire was, in fact, the ground wire . I'll get to soldering the wires to the proper points when I can.

Thanks

 

[quadomatic]

I was thinking about using a GBA d-pad for the dpad mod instead of making a dpad out of the foam and stuff. I disassembled my gba and now I have the pcb...any advice on how I can remove the d-pad portion of the PCB and find where to solder for the directional buttons?

UPDATE: Just went ahead and soldered the wires to the correct points, all the directions register great. Guess soldering to the traces isn't as difficult as was expected. Now I'll have to finish off the "easy" part and attach the plastic pieces for the dpad.

I'm not sure I'll get around to the d-pad push button, since i can't really think of anything I need it for as of yet.

 

[bacteria]

The way buttons register is actually rather simple. You have a (common) ground one on connection and one for the button itself (eg "up" or whatever). When you press that button the two contacts connect completing the circuit. Ground is common as it is used for all connections, and ground is also the negative battery terminal. It makes sense that the directional connections you needed were in the same contact location!

Use a proper d-pad rather than the method in my old guide - better to do it properly! Yes, a GBA one is fine, or a game'n'watch mini (better as you have traces to work with which are more visible).

Centre click button - used for some games, etc - rig up a button on the back of the GP2x case and have the button there for when you need it.

 

[quadomatic]

The way buttons register is actually rather simple. You have a (common) ground one on connection and one for the button itself (eg "up" or whatever). When you press that button the two contacts connect completing the circuit. Ground is common as it is used for all connections, and ground is also the negative battery terminal. It makes sense that the directional connections you needed were in the same contact location!

Use a proper d-pad rather than the method in my old guide - better to do it properly! Yes, a GBA one is fine, or a game'n'watch mini (better as you have traces to work with which are more visible).

Centre click button - used for some games, etc - rig up a button on the back of the GP2x case and have the button there for when you need it.

I finished the ugly d-pad version. It actually works decently well...but yeah, I want to replace it with a GBA d-pad. The question is, how do I know where to solder on the pcb (revealing the traces, which ones), and how exactly should I separate the D-Pad part of the pcb (scissors?) from the gba mobo (seems kind of a shame to hack up a perfectly good gba, but its really the cheapest option). Well...wait...I have my PS2 Dual Impact 2 controller PCB. I think the traces are visible on it. I already chopped the hell out of it...err, I see the traces but I don't know what's what. Here...I'll take pics of the PS2 PCB and the GBA PCB.

Also, can I use the tip of my soldering iron to melt a hole for the d-pad, or should I be using a piece of metal being heated up by the soldering iron?

UPDATE: WOW, just played a round of street fighter vs marvel super heroes (or w/e its called...this new crappy looking d-pad mod is WORLDS better than the joystick. Only quam I have with it is that pulling off the specials (down down-left, right 2x plus punch) seems difficult, but that might just be me. Double tap seems kind of difficult too. I think I'll be doing this with the GBA d-pad then. Could someone please answer my above questions?

I'm doing this to hold me over till I have the funds for Pandora (gonna be till December probably...at least), but I'm guessing a GP2X MK2 with a GBA D-Pad might be worth something :lol:

UPDATE 2: Here are the PCBs I can work with.

PS2 Dual Impact 2 PCB:


GBA D-Pad PCB


Both are about the same size.

UPDATE 3: It seems like it's really easy to uncover the copper traces on the Dual Impact 2 controller, and its the right size for the GBA D-Pad. I think I'll be using that one then. How can I cut the Dual Impact 2 PCB off? And...how do I know which traces to solder to? I can follow 3 traces, from the left, up, and right, but the trace from the down button seems to lead off to the right button...kinda confused.

 

[palmertech]

Each of the contacts on that dpad have two sides, ground and signal. The signal is separate for each direction, and the ground is shared. So just look on the other side that is not connected to the other buttons for signal!

 

[mrsnature]

A assume you don't have a rotary tool like a dremel, that's the most ideal tool for making the hole. This is actually the part I didn't mess up when i tried doing a dpad mod...shame i had to repair it back to how it was when I decided to go back to the joystick that's where one of these came in handy:

Plastic Donuts

very cheap and custom made plastic shapes

 

[quadomatic]

Each of the contacts on that dpad have two sides, ground and signal. The signal is separate for each direction, and the ground is shared. So just look on the other side that is not connected to the other buttons for signal!

Ah, I see. I can see that on the Dual Impact 2. Since the traces are absolutely enormous, I'm going with the Dual Impact 2 for the pcb. Still though, how do I cut off the dpad pcb? And, do I solder the ground wire to the ground on the d-pad pcb?

mrsnature: nope, I haven't got a dremel (or...there's a decent chance that there IS one somewhere in my house I could use, but I have no idea how to use one, and I'm not sure my dad would be cool w/me using it.