Button press wiring question

[demogo]

Hi -- relatively simple question (I hope) that I'd love to see some input on.

Basically I'm experimenting, trying to get 2 boards to work in the same cabinet (and for now I'll swap Jamma cables when I want to switch boards). I also want to tie the button wires from one board (Gauntlet Legends) to the main Jamma harness wiring for the appropriate buttons so that I don't have to make up custom control harnesses for each game and swap them.

In this particular case these GL buttons are being driven by wires that are not on the standard Jamma wiring. And yes, I have the game set to use 8 way sticks but even so the button wiring is handled not on the Jamma harness.

Anyway, the other board is NBA Jam.

So I want the NBA Jam 'run' button to be wired to the GL 'turbo' button for example. So no matter which board is plugged in I won't have to swap control harnesses.

So my expectation is that whatever button wire I have on the Jamma harness will be pulled down to ground when the button is pressed. Correct?

So if I take a wire and touch the P1 shoot wire from Jam (while Jam is up) and touch it to the P1 fight wire from GL (while it is off), Jam acts like the button was pressed. But I didn't ground it?

If I do the same thing on P3 (so I'm not using the Jamma harness at all) and am using the kick harness from Jam then I can touch the appropriate P3 wire together with the GL button wire (which is off) and it DOESN'T act like the button was pressed (until I touch it with a ground wire).

What gives?

Then I can take the same GL wire I used in the P3 test above and touch it to the same P1 shoot wire from Jam and it acts like the button was pressed?

I'm really confused.

 

[demogo]

For what it's worth, when I probed each of the wires with my DMM set to 20v dc, I got the following readings. (Jam is powered, GL is not)

P3 button from GL -> 0v
NBA Jam kick harness button -> 6.05v

P1 button from GL -> -.13v
NBA Jam jamma harness button -> 6.0v

 

[demogo]

Bump -- anyone????

 

[demogo]

Come on -- somebody?

Am I really the first person on KLOV to have tried tying together controls to more than 1 game?

No one has any thoughts or ideas or can compare it to how it should be working on just one game?

No workarounds or alternate ways of solving the problem or experience with such things?

Worst case I guess I'm looking at having to create multiple control harnesses or adapters that would have to be swapped with each game and I really don't want to do that if it can be avoided.

 

[VectorJunkie]

Hi -- relatively simple question (I hope) that I'd love to see some input on.

Basically I'm experimenting, trying to get 2 boards to work in the same cabinet (and for now I'll swap Jamma cables when I want to switch boards). I also want to tie the button wires from one board (Gauntlet Legends) to the main Jamma harness wiring for the appropriate buttons so that I don't have to make up custom control harnesses for each game and swap them.

In this particular case these GL buttons are being driven by wires that are not on the standard Jamma wiring. And yes, I have the game set to use 8 way sticks but even so the button wiring is handled not on the Jamma harness.

Anyway, the other board is NBA Jam.

So I want the NBA Jam 'run' button to be wired to the GL 'turbo' button for example. So no matter which board is plugged in I won't have to swap control harnesses.

So my expectation is that whatever button wire I have on the Jamma harness will be pulled down to ground when the button is pressed. Correct?

Yes, grounding the control line for the button will trigger it. They are normally open.

So if I take a wire and touch the P1 shoot wire from Jam (while Jam is up) and touch it to the P1 fight wire from GL (while it is off), Jam acts like the button was pressed. But I didn't ground it?

If I do the same thing on P3 (so I'm not using the Jamma harness at all) and am using the kick harness from Jam then I can touch the appropriate P3 wire together with the GL button wire (which is off) and it DOESN'T act like the button was pressed (until I touch it with a ground wire).

What gives?

Then I can take the same GL wire I used in the P3 test above and touch it to the same P1 shoot wire from Jam and it acts like the button was pressed?

I'm really confused.

I found this modification for the 6-in-1 Jamma switcher when you use a Kick harness. Looks like they install diodes between the harness control wires and the button to ensure electrical flow in one direction.

http://forum.arcadecontrols.com/index.php?topic=93600.0

Some other references..

http://forum.arcadecontrols.com/index.php?action=printpage;topic=85901.0

http://forums.arcade-museum.com/showthread.php?t=58474

They all seem to be saying the same thing. Connect the wires like you expected to be able to do, but put a diode between the each wire from board and its target button. it looks like most signal diodes will work. One of them use 1N4004 diodes from somewhere like Radioshack or Fry's, etc.

http://www.radioshack.com/product/index.jsp?productId=2036270

Just wire the diode with the cathode toward the button according to that threads above and that should do it. I have never done any of this, so I am going by the fact that it does make sense and they all say to do the same thing.

-VJ

 

[R3LL1K]

I have kick harnesses connected to a Tekken 3 and SFIIHF at all times and I haven't had any issues. If having both games wired causes problems you can use diodes on the wires to clear them up.

 

[demogo]

Thanks -- that's what I'm coming to understand.

I'm having other bizarre symptoms too -- like getting a 'ground' effect from a wire that's carrying 5v. Wow, I'm in over my head.

It actually was carrying 6v which was pointed out to me as WAY overdriving the board -- that's what I get for buying a cab and not checking the voltage levels that the power supply was sending out.

 

[demogo]

OK, does this make sense?

I turned the power supply down and am now getting readings of right at 5v on the button wires from the active game.

If I take the ground from the currently powered game's Jamma harness and a button wire from the inactive game (GL) and check voltage I get -.13. How do you get negative voltage? Is this just telling me that the inactive game has less voltage on that line than the active game's ground line?

I figured .10 volt -- maybe I can check for resistance on the inactive line to see if it's been pulled down to ground -- w/o blowing anything out on the multimeter because the voltage is so low.

So I set it to ohm 2000K and measured it and got a reading of -519. What does this mean???

 

[VectorJunkie]

OK, does this make sense?

I turned the power supply down and am now getting readings of right at 5v on the button wires from the active game.

If I take the ground from the currently powered game's Jamma harness and a button wire from the inactive game (GL) and check voltage I get -.13. How do you get negative voltage? Is this just telling me that the inactive game has less voltage on that line than the active game's ground line?

I figured .10 volt -- maybe I can check for resistance on the inactive line to see if it's been pulled down to ground -- w/o blowing anything out on the multimeter because the voltage is so low.

So I set it to ohm 2000K and measured it and got a reading of -519. What does this mean???

You need to just put the diodes on there and not mess with why it doesn't work without them. It is possible to have a floating ground which sounds like what your seeing. Ground isn't really ground unless you ground it. Basically, the inactive game is not grounded (at least not where your measuring it) because it isn't hooked up to the Jamma harness. If you grounded the secondary (disconnected) board, that would probably go away.

-VJ

 

[demogo]

You need to just put the diodes on there and not mess with why it doesn't work without them. It is possible to have a floating ground which sounds like what your seeing. Ground isn't really ground unless you ground it. Basically, the inactive game is not grounded (at least not where your measuring it) because it isn't hooked up to the Jamma harness. If you grounded the secondary (disconnected) board, that would probably go away.

-VJ

Thanks, man.

I'll go get some diodes and have at it.

Even when I'm taking baby steps here I'm learning. When I win the lottery and can retire I'll go take some electronics classes at the local community college so I can be *really* dangerous.

Thanks again for the help!

 

[VectorJunkie]

Thanks, man.

I'll go get some diodes and have at it.

Even when I'm taking baby steps here I'm learning. When I win the lottery and can retire I'll go take some electronics classes at the local community college so I can be *really* dangerous.

Thanks again for the help!

No problem. If I knew more I would explain it, but sometimes I just go with what others know. It makes sense enough to me that you can get the current from the one board running backwards into the other game. So the diodes will prevent that from occurring. BTW - You can subscribe to podcasts for electronics corse lectures in iTunes and watch them when you have free time.

 

[YellowDog]

You may need to run a ground wire to the frame of each board and to the power supply ground. If you have the boards mounted on those standoff, they act as insulators and the unplugged board will be floating with regard to the power supply and the powered board. Just tie the screw at the corner of each board to the power supply and see if you are having the same issues.

ken

 

[demogo]

You may need to run a ground wire to the frame of each board and to the power supply ground. If you have the boards mounted on those standoff, they act as insulators and the unplugged board will be floating with regard to the power supply and the powered board. Just tie the screw at the corner of each board to the power supply and see if you are having the same issues.

ken

Thanks, Ken! 2 cents of wire is worth experimenting with!

If not, then there is the diode route...

 

[demogo]

I took one wire from the cab ground to the GL board mounting screw and GL is the inactive board in this case and it didn't change anything that I could tell when I retested the connections.

I didn't run the other wire to the active board mounting screw but it should be grounded via its connection to the Jamma harness, right?

In any case, I snagged two IN4004 rectifier diodes from RS and tested with those and sure enough, they did the trick. I tested the voltage coming out of the one diode at 4.7v and then connected the outputs together from the diodes and it did not trigger the button press signal. When I added a ground to the joined outputs the button press signal worked as expected...

 

[VectorJunkie]

I took one wire from the cab ground to the GL board mounting screw and GL is the inactive board in this case and it didn't change anything that I could tell when I retested the connections.

I didn't run the other wire to the active board mounting screw but it should be grounded via its connection to the Jamma harness, right?

In any case, I snagged two IN4004 rectifier diodes from RS and tested with those and sure enough, they did the trick. I tested the voltage coming out of the one diode at 4.7v and then connected the outputs together from the diodes and it did not trigger the button press signal. When I added a ground to the joined outputs the button press signal worked as expected...

Excellent and congratulations!!! Glad you got it working.

 

[demogo]

Well, that's my 'proof of concept' anyway.

Now I have 20 connections that will need this treatment for a grand total of 40 diodes!

3 buttons * 4 players = 12 wires
1 joystick * 4 switches * 2 players = 8 wires

Now I have to figure out how to mount all these things in a way that makes sense and will last...

 

[TK_Monkey]

Well, that's my 'proof of concept' anyway.

Now I have 20 connections that will need this treatment for a grand total of 40 diodes!

3 buttons * 4 players = 12 wires
1 joystick * 4 switches * 2 players = 8 wires

Now I have to figure out how to mount all these things in a way that makes sense and will last...

This may be overkill at best, and might cause issues at worst. To my understanding, as long as you're swapping the jamma connector between boards and want to wire the extra buttons off the kick harnesses together (with the sticks and standard 2 buttons going through the normal jamma harness) you should only need the diodes for the kick harness combination wiring. For example if you wanted to do this with two SFII boards (6 extra buttons and a ground on each kick harness, total 7 wires per kick harness) you'd need 14 diodes for the two kick harnesses combined. You shouldn't need to do it with the joysticks and buttons carried on the standard jamma connection as well. KLOV user zenomorp is the one who did that thread at a-c for his multi-kombat machine, and I don't remember him having anything in his original video for the cab (his youtube acct got screwed up and he had to make another one, thus having to redo his video) which showed the wiring about having the diodes for anything other than the kick harnesses.

Glad that thread got linked, I'd been looking for the image in it to get the part number for the diodes for a while, as I'm going to be needing to do this when I get the 6-1 running in my SF cab.

 

[demogo]

This may be overkill at best, and might cause issues at worst. To my understanding, as long as you're swapping the jamma connector between boards and want to wire the extra buttons off the kick harnesses together (with the sticks and standard 2 buttons going through the normal jamma harness) you should only need the diodes for the kick harness combination wiring. For example if you wanted to do this with two SFII boards (6 extra buttons and a ground on each kick harness, total 7 wires per kick harness) you'd need 14 diodes for the two kick harnesses combined. You shouldn't need to do it with the joysticks and buttons carried on the standard jamma connection as well. KLOV user zenomorp is the one who did that thread at a-c for his multi-kombat machine, and I don't remember him having anything in his original video for the cab (his youtube acct got screwed up and he had to make another one, thus having to redo his video) which showed the wiring about having the diodes for anything other than the kick harnesses.

Glad that thread got linked, I'd been looking for the image in it to get the part number for the diodes for a while, as I'm going to be needing to do this when I get the 6-1 running in my SF cab.

TK,

You're right -- I had a mistake in my posting but it doesn't change much. I only need to do this to 14 connectors (28 diodes) rather than 20/40.

Keep in mind that in my case I have two boards tied together, one is powered one is not.

One big issue is that the buttons on Gauntlet Legends (even when the dip switch is thrown to 8 way joys from 49 ways) are still carried on wires independent of the Jamma harness. So I pretty much have to do something like this to get them on to the standard wires on the same harness so that I can reuse the harness for other games.

For some reason that I don't understand, the p1-p2 buttons (6 connectors) "ground" when the appropriate jamma wire connects to the appropriate GL non-standard wire. When I add the diode all is well. But when I do the same with the p3-p4 button wires I can connect them w/o a diode and everything is fine. I have no clue as to why this works for the p3-p4 but not the p1-p2.

Joys on the p1-p2 controls are covered by the existing Jamma harness so no issues there.

Joys on the p3-p4 controls 'ground' with the kick harness p3-p4 joy wires when I connected them. So this is 8 more connectors to be dioded. Again, I have no idea as to why.

It's either splice the wires together or make up a bunch of custom connectors and swap all of them out for p1-p4 when I want to switch games. I can do this but it'll become a hassle before too long.

If anyone has any ideas as to why this is showing up on some of the buttons but not all of them please let me know.

Or if my plans to diode up the 14 connections really can hurt something then again, please let me know. I don't want to fry anything. I guess I could use these toggle switches to switch the button/joy lines instead:

http://www.mouser.com/Search/Refine.aspx?Keyword=108-ms-550a

 

[TK_Monkey]

Didn't realize the GL sticks ran separate from the normal jamma wiring, that could be a royal pain. Honestly I'm not sure of how to proceed at that point. FWIW, the 6-1 I'm going to be putting in (and the one zenomorp put in the MK) only runs power to one board at a time, the rest are powered off, so it's basically the same situation, just more boards, but the joystick thing adds a whole new level of...fun.

 

[demogo]

Didn't realize the GL sticks ran separate from the normal jamma wiring, that could be a royal pain. Honestly I'm not sure of how to proceed at that point. FWIW, the 6-1 I'm going to be putting in (and the one zenomorp put in the MK) only runs power to one board at a time, the rest are powered off, so it's basically the same situation, just more boards, but the joystick thing adds a whole new level of...fun.

Well, it's the buttons that are run separately. It's a side effect of the 49 way sticks gobbling up too many wires on the jamma harness so they had to get the wires to the buttons somehow.

What I would have *hoped* was that when you threw the switch to go to 8 way joysticks it would have gone back to carrying everything over the standard jamma wires but it didn't. It carries everything but the buttons on the correct jamma wires now.

Not sure what's up with the joystick wires on p3-p4 'grounding' when they are touched by the kick harness joy wires.

Even more infuriating is that there are Gauntlet Dark Legacy conversion boards out there that use essentially the same hardware where the buttons are routed over the standard Jamma wires.

I keep looking for ways to throw dip switches or jumpers and get my board to do the same thing but I'm not having much luck so far.

From a manufacturing perspective it only makes sense they were using essentially the same hardware because it would cost more money to go spin new boards -- I just can't identify the differences...