sharing ipac and dreamcast

[Nightfalls]

Some time ago I made a question about using an ipac and a dreamcast pad hack all together in the same control panel (for 1 player only). I've read now that you can have problems of voltage if you connect both devices at the same time. Other people say it simply wont work. But, my panel will be a desktop panel and I will never have to connect it to the dreamcast and the pc at the same time. My idea is to have two wires connected together to the same pin of the microwitch, one going to the corresponding function of the ipac and the other going to the corresponding function of the dreamcast pad. For the ground I'd have to daisy chain for the dreamcast pad. I don't know if this is also necessary for the ipac (I guess it is). Now, will this work? Thank you.

[crashdmj]

I want to know the answer to this to. I was thinking of hacking 4 pads (for 4 players) and doing the same with wiring the 4 hacked pads to the microswitches and having the Ipac also take the 4 players like a normal arcade cab?

[radiator]

i've just been trying this...and it doesn't work...even with the DC pad not connected to the DC

the DC controls work fine, but when you start using the PC, a single button press registers as every button (ie, when you press button 1, the PC/IPAC think you've pressed every button at the same time)

i think the answer is diodes - you'd need a diode on every wire that goes to your DC pad, so then the current will only flow one-way...

i'm gonna try it in a few days, i'll let you know how i get on

 

[crashdmj]

Yeah let us know please.
Derek

[Nightfalls]

:( Then I think I will abandon the idea and use the method I've already tried and work fine: a psx pad hack. I have adaptors for dreamcast and pc and they all work perfect (I haven't noticed any delay nor key blocking). Since my panel is for one player, I think it's the best solution.

[CthulhuLuke]

Ok, here's the situation with a dreamcast pad hack.  For some reason, when you have the ground of the dreamcast controller hooked up with another interface such as an I-pac, it draws away 5v somehow, and renders your I-pac worthless.  But here's what you do, go find a DPDT switch, and hook it up so one way hooks up the controls to the dreamcast grounds, and the other way hooks them up to the I-pac grounds.  This is the easiest way to fix this problem that I know of, and is what I'd setup if I wasn't so lazy.
     -Luke

[Nightfalls]

Let me ask a question: what's a DPDT switch? If I just have to add one external switch for the ground wire, I think it must not be difficult. Ipac has some advantages over the psx pad hack, since you can program more functions.

[radiator]

go find a DPDT switch, and hook it up so one way hooks up the controls to the dreamcast grounds, and the other way hooks them up to the I-pac grounds....

tried that, doesn't work...

you need diodes...the switch will toggle between the DC and IPAC, but the IPAC side of things still messes up (DC works flawlessly though...but the IPAC still thinks that every input is connected to every button)...

should (hopefully) be getting a bunch of diodes tonight (if my old man remembers to go to Maplin for me )

 

oh, nightfalls, DPDT stands for Double Pole Double Throw - basically, a switch with 6 connectors (2 sets of 3 - there is a common input, and 2 selectable)

[rampy]

Well... wouldn't a SPDT switch work (if you had one for every button... it's NOT enough to just break the ground.... ) to isolate the DC from the ipac and versa vicE?

It's my understanding that's the only way to go.  People have hypothesized about using something like one of those old parallel port switchers to switch from DC to IPAC ... and I believe SNaaack even tried one unsuccsefully ---> but I *think* the issue is that his was a "cheapo" one that only cut over the ground and didn't cut over ALL the pins of the parallel port connectors...  (i.e. the full isolation we require)

I'd be if you found a "real" one of those switchers that didn't "cheat" and switched over a bunch of contacts from one side to the other you'd be in business...  

Another approach would be to wire up two harness  or sets of molex plugs or whatever and switch between them manually... *shrug*

Rampy

[radiator]

yeah, one of those printer switches would work...but it's probably easier and cheaper to use diodes (20 diodes, enough for 2 DC pads, costs around

[crashdmj]

Wow, if this works someone is gonna have to dumb it down for me and my 4 player panel. LOL  

[Nightfalls]

Hmm after reading all this I think I'll buy a cheap PSX pad and hack it. I already have 2 psx-dc adaptors and 2 psx-usb adaptors. They all work fine: no problems of blocking and perfect response with absolutelly no delay. For my new control panel I'll use 6 buttons for the action and 4 buttons for extra features: coin, start, etc. I think a psx pad is the best choice. First I thought of buying an ipac + dreamcast pad, but it's not worth for a 1 player control panel, although the ipac is such a fantastic piece of hardware and I'd really like to have one.

[radiator]

right, just got my diodes, wired everything up.....
.....perfect!

i'm doing it like this:


the anode (end with black stripe) on the diode needs to be pointing AWAY from the DC pad...
i used 5w zener diodes (cost about 6p each)

[CthulhuLuke]

Hmm.. that's interesting, I'm glad you got it to work.  On my brother's Mas stick, it was originally wired to a dreamcast interface, but I took the liberty of hacking in a PSX pad, and had the DC stealing voltage problem, so I wired up a SPDT switch between the two grounds, and it works almost flawlessy, except the turbo sometimes turns on, which would definitely indicate to me that all the buttons were suddenly pressed.  So a 5V diode seems to do it, i think one of us needs to write this down in the BYOAC interface section to help out other people in the same situation.
   I wonder if my dad has any 5v diodes, my guess is he does.
    -Thanks for the conclusion to the DC and Ipac wiring dilemma  *however you spell that*
     -Luke

Oh btw, whats the rating on those diodes you used?

[crashdmj]

Any good place to buy em?

[radiator]

try Maplin if you're in the UK - order code:QH07H

if you're anywhere else, I've heard are pretty reliable

Maplin simply states that they are Zener diodes, 5.1v, with a tolerance of

[crashdmj]

Are the ones offered by Bob Roberts: 1N4733 5.1 volt zener diode, the ones I would need?
Derek

[rampy]

Rat shack has 'em if you want brick and morter style...

*shrug* (although if you are already in the midst of an order, by all means get 'em from bobby)

Rampy