I suppose building a circuit board and and design some software might work, but seems much more involved, just like Savannah likes it!
It would probably be easier than even I made it out to be. I realized today at work that a paired NPN & PNP transistor and a front end GUI that supports something like the LED-Wiz would probably make it extremely easy. I'm not sure which NPN/PNP pair I would use though. It's just a signal line so I imagine just about any would work fine.
In any case, I'm reasonably certain a simple SPDT switch would be even simpler than buying a new ipac4 and reconfiguring MAME.
Can you provide more info on how to do this with the transistors? I'm looking to do the same thing and will also have a LED-Wiz. Thanks.
I'm just an amateur, so I could be wrong. I don't have an LEDWiz either so I can't test my designs. Maybe Randy can verify?
In any case, this is what I came up with.
Wire the control panels positive terminals to the appropriate connections on your controller (iPac or KeyWiz). However, each panel will get their own ground loop, don't connect them to anything yet.
Grab a PNP and an NPN (I haven't figured out the exact part # yet. The only complementary ones I know of like the 2N2222/2N2907 have all been out of production for a while.) and tie the collector of the PNP to the emitter of the NPN. If you use a standard TO-92 packaging, you'll find that if you place the flat of each pair facing each other, then the correct legs line up for soldering
. Mount the pair on something hard, they're less likely to get mangled or short out during handling.
Base of each pair is tied together which is connected to the LED-Wiz circuit.
The last pin on each pair is then tied to the two ground loops. One pin to one ground loop. The other pin to the other ground loop.
The LED-Wiz I have to guess on. I also don't know if Andy's design is the same. But I guess to play it safe, one should use a small general purpose diode like a N4004 (is that the right number?) and a small resistor.
Program the LED-Wiz + FrontEnd and you have an automatic switcher.
I'm uncertain of is whether the transistors will let enough current pass to drop the voltage across the switches enough so the controllers can sense it properly. I'd like to construct a prototype, but I don't have any controllers to play with yet.
Anyhow, that's my theoretical design. Do any of the circuit experts see anything I may have missed?