Gp2x Joystick Exposed - The Internals


DaveC

Internal Development
Joined
Mar 4, 2004
Messages
9,208
Well I received the joystick assembly finally and proceeded to dissect and photograph.

The way it works is there is a "hat" that is common and tilts to make contact with contacts in the base. There are 8 contacts in the base. A spring keeps the "hat" from making contact unless force is applied. There is a center blister switch that closes when the brass shaft is pressed. There is no threading and the brass stick and metal hat are keyed so they don't rotate. It is a simple arrangement.

If you notice, and this is important, the X and Y direction contacts are SMALLER than the diagonals! THIS is why it is too easy to hit the diagonals accidentally as the target is bigger. Now it is bright and shiny clear. I don't know why the switch mfg didn't make the contacts the same size but they didn't kind of dumb. Then GPH didn't know any better so they just threw it in without testing, dumb and dumber.

The fix for GPH would be to orient the assembly at a 45 degree angle to how it is now, then change the wiring so that the now larger contacts correspond to X and Y and not diagonal. This would improve the X and Y control.

*CraigIX you may want to contact GPH and suggest that they do this in future batches, rotate the stick assembly 45 degrees and change the wiring accordingly.*

The mod for the rest of us? Well for those handy with an iron you could cut small thin strips of metal and solder to the X,Y direction contacts. What this would do is both increase the X,Y bias (since the metal would be slightly higher it will be easier and more likely to hit) and narrow the dead zone too. My next mod...

gp2xjoystick.jpg
 
-.- said:
The mod for the rest of us? Well for those handy with an iron you could cut small thin strips of metal and solder to the X,Y directions. What this would do is both increase the X,Y bias (since the metal would be slightly higher it will be easier and more likely to hit) and narrow the dead zone too. My next mod...

Those bastards! That bigger thing for diagonal is kind of stupid really... The gp2x is more 2d orriented and by making the diagonals have a bigger surface it makes them look like it was built for 3d?

I hope you make a guide or something for the moding im gladly going to do this, I dont want to sell mine then have to buy a new one it takes too long :p

Nice info though!

EDIT: Is it safe to 45degrees shift ours? or will that screw up everything? ^.^
 
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Heck, if you took the time to de-soder it and put something else in, why not put something else in all together? Is this a part that GPH had specifically made or is it generic and a company makes another kind of controller with the same pin-out, i.e. a d-pad or something.

Remember the Turbo Touch 360 controllers? I liked mine for the SNES, worked all through my SNES's life. It was all the first player used, while the one that came with it wore out and was replaced. It still works infact, and I use it when I fire up the old SNES.

Thanx,
Stan
 
EDIT: Is it safe to 45degrees shift ours? or will that screw up everything? ^.^


It would be hard because the holes in the board and the traces are already set for the way it is. Adding metal contacts would be easier.
 
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Heck, if you took the time to de-soder it and put something else in, why not put something else in all together? Is this a part that GPH had specifically made or is it generic and a company makes another kind of controller with the same pin-out, i.e. a d-pad or something.


Thanx,
Stan

It is a generic part made by Alps. They can be found at many electronics supply places.
 
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wow i guess that the reason why its too easy to hit diagonals is because they are 2x bigger than left or right.
 
Hmmm, one _could paint over parts of the diagnals with an enamel paint, shrinking the diagnals... it might make it harder to hit multiple zones at a time, and shrink those offensive diagnals :) if I was adventurous, and had a second unit for when I destroyed my first, I'd try it :D
 
So we have a "natural" diagonal bias here done directly in a hardware...

The GPH must be clueless about its own hardware really... This isn't for first time as well. I'm not that surprised thought - they probably just chose a stick they found first and voila! This would be in an order of previous things we had to deal with.

This is the most serious gp2x's issue after only the lcd's interlacing (assuming it will not be fixed).

edit: I have another idea!

A piece having shape of circle what would be putted in a place of those contacts. At bottom it should be sticking to them and at top exposed as those pesky contact are. Of course this time having valid arrangement.

This way it would be easy to anyone to fix it (not soldering needed, just some glue).
 
DaveC
Do you have a part # for that? I want to find a datasheet for it.
 
Hmm, maybe the manufacture just makes one the exact same but with the x/y bigger than the diagonals, or have them all equally sized. Need to look at that, if that's the case some adventurous person could switch it out. I'm not comfortable doing it myself, but if GPH fixes it then I would order another then send my old one off for someone to change.

Thanx,
Stan
 
I wonder if you could use a stanely knife or something else to trim down the diagonals... the problem is they look molded into the plastic.

Yeah i agree, maybe the manufacturer does a similar part.

So who makes them and what is the part number?
 
Maybe the "bigger" diagonals were meant to be bigger X/Y zones, and GPH just put in the component at a wrong angle.
 
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