Hacking Circle Pad wiring / test points?

[TwitchPlays3DS]

I'm trying to hook up an external control for the analog input on the 3ds. I bought a few extra circle pads and was going to just carefully modify the ribbon cable to be used in my project, but I figured someone might know which test points on the 3ds / 2ds correlate to the ground / x / y / vcc points of the circle pad? That would be way easier. I assume they would be numbered the same for 3ds and 2ds, as the digital inputs (abxy, dpad, LR) are numbered the same on both systems.

If not, does anyone happen to know which lines on the ribbon cable correspond to what on the circle pad part itself?

 

[Snailface]

If you're planning to do what your name suggests (with pokeXY), why not hook up the directional control to the d-pad? It would make the input programming side easier and less of a burden on the users as well.

 

[TwitchPlays3DS]

I have all digital inputs hooked up. We completed pokemon x a few weeks ago (there are some vods still on my channel, http://www.twitch.tv/twitchplays3ds) but there are some games (including one stupid section in pokemon x/y) that require the circle pad.

 

[TwitchPlays3DS]

from imaginglabo

1: GND 2: TP69 3: C103 4: TP68

I am thinking TP 69 and 68 and the x and y inputs, with the c103 being where he is pulling vcc from

 

[Kyohack]

It shouldn't be too hard to figure out if you have a multimeter on hand. Whatever doesn't have voltage is ground, and assuming the XY axes are potentiometers like typical joysticks, then you can just move them to determine which of the other 3 pins give voltage changes for which axis. The pin with constant voltage is VCC.

It's quite a coincidence to see you posting here! Just yesterday I was looking for 3DS Circle Pad pinouts as well, and came across your Twitch page. I am working on a project similar to yours, dealing with input simulation on the 3DS. Any chance you'll be releasing the source you used with your Raspberry Pi? I've been considering picking one up, and it would be fun to have some source code to tinker with, for a project that interests me.

I've managed to get the digital pinouts working with an Arduino Uno I have on hand, and all I have left is to get the Circle Pad working. If I find the pinouts before you, I'll be sure to post them here. Though I may have to switch to using my Arduino Mega for more PWM outputs....

EDIT:
Oh sweet, it seems you found them already!

 

[TwitchPlays3DS]

Controlling the digital inputs is trivial after you hooked up the raspberry pi - I used rpi.gpio (set the circuit low for at least .16 or so seconds = button pressed). I modified this branch of twitch-plays on git https://github.com/aidraj/twitch-plays

Someone else on reddit did a similar thing with an arduino, and has his modified code up

I bought an mcp4922 2 channel DAC, so I'll have to learn how to send SPI stuff. I probably could have done it with a few voltage dividers like the controller mod for vectrex, but oh well.