2 Player CP Wiring Question

Tech Talk
#1

While similar to the “2 PCB in one joystck” thread question its not the same.

I need to know if this will work.

I have a 2 player control panel: 1 joystick & 7 buttons for each player.

This is going to be interfaced with 2 hacked dreamcast gamepads via a DB25 connection.

I had planned on only having one ground wire chained to every button on the CP.

So thats 22 signal wires and 1 ground wire.

The question is, when using 2 gamepads can the ground be common between them? Or will I have to use another one of the DB25 pins and run a separate ground for player 2 controls?

Visual Diagram: http://lh5.ggpht.com/_nNcVLzdKf-c/SZT56ekjd6I/AAAAAAAAAZQ/AoGL3jdCxfs/s800/dreamcast-wire-diagram.jpg

#2

You’re gonna need to run a separate ground from the P2 controller PCB to the buttons and stick. If you use the ground from the P1 controller PCB, all of P2’s inputs will register as if they were done by P1. It seems though that you’re doing something incredibly complicated for a 2P control panel setup. Why have 2 controller inputs come from 1 DB-25 connector? If you were to use two separate DB-15 connectors, it’d be much easier in terms of wiring them up and you won’t have to cram two PCBs into a project box or whatnot. If you had two separate connectors, you could also make your setup work for more than just the Dreamcast with a lessened burden than if you tried to get signals running through a single connector.

#3

Mostly because its a modular setup,

Its going to this: http://www.monoprice.com/products/product.asp?c_id=101&cp_id=10103&cs_id=1010305&p_id=1354&seq=1&format=2

And another one of the outputs is going to an I-PAC for Mame and stuff. I could not think of an easier way to have it work for multiple systems. Where one of the connections is always on (the PC)

Thanks for answering my question though, it wont be hard to split the ground on the DB25 for P1 & P2. I’ll splice them together on the I-PAC and leave them seperate for any consoles. I still have one wire left that would be good to add a “insert coin” button.

#4

So this looks good right?

http://lh6.ggpht.com/_nNcVLzdKf-c/SZUIedvzDdI/AAAAAAAAAZY/MyP_OvsqngU/s800/dreamcast-wire-diagram2.jpg

I can even use that last pin for a coin button for mame and be all set. Now its just a matter of fabricating and soldering it all once the parts are here.