Homemade IIDX controller

[infamous360]

I want to build a doubles deck... I have the sanwa keys on order... this is what i want it to look like http://bemaniasc.com/img/gallery/re/RE_800010.JPG I would order one from there but I dont have 1k

How would I build the turntable circuits? I am using 2 PSX controllers as the boards.. each board is getting 7 buttons and a turntable

[MonMotha]

What most people do is hack apart a KOC and use the optics and such from that.  If you'd rather do it yourself, I'd suggest going with what beatmaniaIII did and use a real optical encoder device (I can take a picture for you some time) driven by a rubber tipped wheel hooked up to your turntable.  That gives higher resolution with less effort, and it seems more reliable.  You could then either hook that up to a KOC or build your own playstation interface.

I specialize in custom interfacing if you like, and I've hooked a IIDX machine up to a playstation before, so I think I can pull this off

EDIT: I took some pictures of a beatmaniaIII turntable for you.

YET ANOTHER EDIT: I think this is how the new IIDX machines work.  Older IIDX machines use a metal toothed disk passing through two optical gates arranged to produce the quadrature output, like original beatmania.

[infamous360]

wouldnt it be easier hook up a spinner to a playstation controller and make a custom nob?

[MonMotha]

That would be the "hack a KOC" approach.  Spinners are known as components as rotary or optical encoders, depending on construction, which is what that bmIII turntable is using.  The IIDX KOC that Konami puts out (you can find one left from the dead US release or buy one from Japan for $$) doesnt use an integrated encoder, but rather two optical gates and a plastic "toothed" disk with the gates aligned for quadrature output - identical to what a rotary or optical encoder outputs.  The controller then interprets these and sends up/down button presses to the playstation.

Some people who build these things by hacking KOCs up reuse the optics and the toothed disk (basically attaching the whole thing to the underside of their fancy turntable), while others just reuse the control and construct their own encoder.  I tend to build my own control because it lets me do some other useful things when hooked up to things other than playstations, lets me remap buttons if I want (gogo DJ station Pro!), and those KOC control boards (at least the US ones) have a nasty tendency to die inexplicably.  Of course, making your own control is a little harder than just soldering some wires down to the right place.

You can't just hook a quadrature encoder directly up to a playstation digital controller.  It doesn't work that way.  A quadrature encoder generates two square waves that are out of phase with each other.  You can tell how fast the device is spinning by the frequency of these square waves, and which direction by which output transitions in a certain direction (high->low or low->high) before the other one.  Clearly, this doesn't look like pressing a button electrically.

There are several ways to convert such behavior into discrete events (emulating a button press), but not without a little logic.  IIDX uses an 8-bit counter which is actually fed directly to the arcade software.  The counter increments once per 64th of a revolution for clockwise rotation and correspondingly decrements upon counterclockwise rotation.  The game then infers motion from the counter data.  Newer machines may have higher resolution as 1/64th of a revolution is actually kinda terrible.  That bmIII turntable would certainly be capable of much higher as the gearing makes the encoder rotate several times per turntable rotation, and most of those encoders have at least 32 pulses per revolution.  The actual IIDX hardware also has a bug in the counter behavior I had to work around when I did my interfacing, but you wouldn't have to worry about that, at least.

[infamous360]

Oh ok I havent opened my KOC... So basicly if I buy 2 of these http://forum.arcadecontrols.com/index.php?topic=48855.0 and wire them to the PSX boards and make toothed disks it will work?

sorry If i sound like a noob... my last project didnt include optics

[MonMotha]

Well, those are exactly what's inside a KOC, so you can just reuse the board from that.  You can reuse the disk, too, to save you some work.  And yes, you could just wire those boards directly to the playstation control in a IIDX controller, though make sure the LED drive current is correct.

[infamous360]

my KOC doesnt work at all anymore sadly and I was going to make an arcade sized turntable...

[MonMotha]

What people do is attach the turntable from the KOC to the bottom of their arcade size turntable.  It saves work.

If your KOC doesn't work, then it's probably easiest to just buy a new one (told you they break).  Like I said, you cannot just hook the outputs of the optics directly to a digital playstation controller.  That won't do at all what you want.

[infamous360]

I am stubborn lol so i am going to buy an ipac, optipac, and a console adapter and build my own.. My KOC only lasted 3 months and I plan on building a controller that will last a while without a lot of work... I had a USKOC and people told me that they have voltage problems... What kind of spinner is best to buy? I have experience will ultimarc and must say that they kick ass so I will probably order from them.

Is it even possible to hook an optipac to an ipac?