Help Dual Modding a Non-Common Ground PCB


#1

Can someone guide me through dual modding a non-common ground 360 PCB? I’ve searched for hours and I understand I have to replace the PCB, but there hasn’t been any step-by-step guide on how to do actually do the mod.

I have a Hori SCV stick and this is what it looks like inside of it:
http://i.imgur.com/Brr6VTI.jpg
http://i.imgur.com/xOIPKGd.jpg?1


#2

Your research is incorrect.

It is common ground, dude.


#3

You do not need to replace the pcb.
You need to add a pcb lol.


#4

Just get a Chimp or a cut down cerberus and solder up some additional wires for the dual mod.


#5

How come it’s a common ground? There’s no wire common ground connecting the buttons together.


#6

Ignore the button wiring, having individual wires for each button is standard in most Hori and Mad Catz sticks.
No not confuse the lack of a daisy chain for lack of common ground.

The Common ground exist on the PCB, as if you trace the wires for each button you notice for each pair, one wire for each button is soldered to what is called a** ground plane**.

See that Joystick harness there, see that Black wire, its the Ground for the Joystick. Now if you take a multi meter and but one probe where the Joystick harness ground is soldered and the outside row on the button wiring you all notice there is a connection. There is your common ground

Think of it this way: The Joystick’s black ground wire, one of each button wire pair, the Black wire on the USB cable and maybe a few other spots are all soldered to a large expanse of copper on the PCB, its that the “daisy chain” is taken care of on the PCB instead of doing a daisy chain in wire if you want to think about it that way. Its not the actual terminology just the whole thing explain in a way those who do not know about electronics can grabs whats going on.


#7

Oh I see! Thanks a lot for explaining.


#8

I have a related question.
I’m working on the same pcb and trying to connect it to a cerberus. Since both are common ground, cerberus only has 1 point per button (signal).
My question is, how do I determine which of the 2 button cables is signal? I’m really hoping its something as simple as ‘closest one to the edge of the pcb’ or something (see 2nd image in OP to know what wires I’m talking bout) :slight_smile:


#9

It looks like (don’t quote me on this) the furthest from the edge is signal. If you have a multimeter, test continuity between those closest pins. They should all be connected together, and to ground.


#10

Although I own a multimeter I don’t actually know what I’m doing with it.
So I touch one end to one of the wires furthest from the edge and another to another one of the wires furthest from the edge and I should hear a beep if they’re signals?


#11

Not really. Set your mm to continuity mode (probably looks like a speaker) and touch your tips together to make sure they beep. Next, pick one of the pins closest to the edge and poke it with your probe. With the other probe, poke all of the pins closest to the edge. You should get a beep from each. If that checks out, with one probe still on that row, poke a ground point (probably one of the black wires from one of the wire bundles). If you get a beep from that, it means that the pins closest to the edge are ground, and thus the pins furthest from the edge are signal. ETA: These directions are based on OP’s top picture, if that makes a difference.

If you need more help with the mm, check out http://learn.adafruit.com/multimeters


#12

Thank you so much! confirmed that the ones furthest from the edge in the 1st pic posted by the OP are indeed the signals.

Thanks again :slight_smile:


#13

Probably a long shot but does anyone happen to know which of the CN_3 & CN_4 ribbons (the grey ones coming out of the harness on the top of the PCB) are the signals for back and home? Only labels there are 1 and 8 next to the first and last pin :frowning:
Under the turbo panel is a small PCB with 8 contact points but again, no labels.

I do have a multimeter but not sure how to identify which is which.


#14

Try: http://img708.imageshack.us/img708/3840/diagramab.jpg

If you want to confirm, go to the buttons. There will (I think) be two overlapping combs per button. One is that button’s signal, the other is ground. Use the MM to find continuity to the points on the main board.