xbox controller thumbsticks

[vanebeard]

Hi, I need to use the analog sticks from an old xbox (Duke) knock-off and I can't trace the pinouts becuase the board is cracked.  Does anyone know how to wire these up?  
The stick has 2 wires that come out of the bottom which I assume are power and ground and then there are 2 sets of 3 pins, on the top and right respectively.  I'd just like to know what signal is carried by each of these pins.  

thanks
vb

[kendrick]

VB, some analog controllers are essentially a pair of potentiometers, one for the X and one for the Y motion. This may transmit a voltage differential to the encoder chip, or the encoder might just measure straight variable resistance. Other types use hall-effect distance sensors to measure how far away the stick is being held from one of the four cardinal positions. Either way, it's hard to know which variety you have in your controller without a picture or a better description of the components. Any chance you can post some photographs, or at least a model number?

-KKC, doing fun things with DNS.

[vanebeard]

They are the standard xbox analog sticks here is a pic, although when I was taking it I realized that they have a pushbutton, so I guess the wires on the bottom are probably just leads for the button and then the pins on either side are just power/signal/ground for the X and Y direction.  You know for sure?
vb

[viletim!]

It's made of clear plastic, you can see right into it! That thing inside is a 100k linear potentiometer, there are probably two of them in there.

[kendrick]

I agree with Tim, it looks like you've got a 100k pot for both the X and Y directions. The center contact on each potentiometer is your common, and the two side contacts give you the variable resistance relative to the position of the stick (with a default center position, I assume.) It goes without saying, in this configuration the stick doesn't translate into distinct up/down/left/right digital signals like a normal D-pad.

Whatever you're connecting this two, make sure that you get the polarity of the values right. In other words, which side contact you elect to use will determine whether or not resistance increases or decreases as you go further in one direction or another. hope that helps you out.

-KKC, out of funny things to say today.

[vanebeard]

Thanks guys that will do nicely.  I thought that was the part number on the side but it actually says 100K so that removes all doubt.  
vb