Basic Wiring Question

[javeryh]

It's about that time... I've never done something like this ans I'm a little intimidated... anyway:

Each microswitch gets two wires running from it - one from NO (normally open) and the other from COM, right?  I know each wire from NO gets wired directly to the corresponding node on the iPAC but where do the COM wires go?  Can I wire one COM node to the next COM node to the next COM node and so on?  If so, what happens to that last wire?  Can I wire it to the first COM node creating a circle or does it go somewhere else?  Or am I way off base here?

Thanks.

[rdagger]

The last com goes to the ground on your encoder.

[javeryh]

Thanks.  So wiring one COM to the next creating a loop is an OK way to go about doing this?

[JonnyBoy]

Yep, you can daisy chain the grounds together and shoot them right over to the ground terminal on your ipac.

[ChadTower]

That is called a daisy chain ground loop.

[menace]

I would recommend a couple of ground loops--that way if you have a bad connection you don't lose everything and its easier to track down the offending bad connection.

[ChadTower]

Yeah, better to do it with each ground loop being the controls of one player.  Don't forget that in a daisy chain, if one connection breaks, they all break.

[SirPoonga]

http://www.ultimarc.com/images/wiring.gif

Don't forget that in a daisy chain, if one connection breaks, they all break.

All behind the break.  In the ultimarc pic if hte ground at the middle button borke only hte left and middle button wouldn't work.

Some people will ground the left button to the ipac to.  That way if something goes wrong with one button it doesn't take out all the buttons behind it.

[javeryh]

OK, so I can daisy chain the P1, P2, P3 and P4 controls (each separately) and run the last wire of each to the ground node on my ipac (so 4 wires go to that one node)?

Thanks a lot.

[javeryh]

http://www.ultimarc.com/images/wiring.gif

Don't forget that in a daisy chain, if one connection breaks, they all break.

All behind the break.

[SirPoonga]

Awesome picture - it's exactly what I'm going to do.  If you did go ahead and ground the left button does that mean that you can pinpoint where the bad connection is based solely on what button isn't working or is the only way to do that to ground each button individually?

Depends on how the ground broke.  Most of the time the connect comes off the spade on the button, so even without the loop as I described all other buttons will work.  However, if someone the wire broke or became unsoldered then it depends on how your grounds are wired.  If wired like the pic (which is from the ipac instructions page) then all buttons that would have gone through the break won't work.

Doing the loop as I suggested depends on what broke.  If the wire came unsoldered just that button won't work.  If the wire broke in between two buttons all buttons will still work as there is a way to get to ground.

Each way has its own benefits.  doing only one route to ground if something goes wrong it will be obvious, a bunch of stuff won't work.  The other route you may not realize something is wrong until you use the failed part, but wiith two paths to ground if one thing goes wrong it all doesn't.  It's a matter of preference on what you want to happen when something goes wrong.

[javeryh]

Great!  Thanks for the info!

[ChadTower]

http://www.ultimarc.com/images/wiring.gif

Don't forget that in a daisy chain, if one connection breaks, they all break.

All behind the break.

[BobA]

If you add another ground to the LH ground connection and take it to ground you will have a true loop and a single break will not disable you buttons.

[M3talhead]

If it helps, I've included pics from my arcade project when I was building it. Notice in the first pic that all the black wires (grounds) are chained. This is done by inserting 2 wires into a single terminal connector and repeating the process until you've formed a complete chain from the furthest control, to your iPac.



The second picture shows how the positive leads are routed in order to complete the circuit for each switch.

[markrvp]

If it helps, I've included pics from my arcade project when I was building it. Notice in the first pic that all the black wires (grounds) are chained. This is done by inserting 2 wires into a single terminal connector and repeating the process until you've formed a complete chain from the furthest control, to your iPac.



The second picture shows how the positive leads are routed in order to complete the circuit for each switch.

But don't wire yours so neatly.  Doing so will "out" you as a sociopath.

[Bones]

I would recommend a couple of ground loops--that way if you have a bad connection you don't lose everything and its easier to track down the offending bad connection.

I also used this approach and used a commoning block. I connected each series of joysticks & buttons to this block. refer bottom left hand corner.

[M3talhead]

Notice 'Bones's use of erratic and unorganized wiring. Do you really want to be getting electrical advice from a person this ---fouled up beyond all recognition--- up?

[Bones]

Notice 'Bones's use of erratic and unorganized wiring. Do you really want to be getting electrical advice from a person this ---fouled up beyond all recognition--- up?

This is a difficult point to argue. You should listen to Metalhead.

[RTSDaddy2]

I'll add two cents, though it's painfully obvious (I think), but I don't recall anyone having said this - and I think I read all posts here so far completely.

Following the ideas in the picture let me also suggest you use different color wire.  For example, I used black wire for my grounds, red wire on all the joystick connects to the IPAC, and green for the buttons.  That way if a button stops working, I check the green connectors first, then look at my grounds to make sure nothing's come loose.  It may sound nutty, but it does help.

[brian23]

I concur on the colored wiring. Makes understanding things much easier. Also, using a wiring block helps from tugging on the ipac if you have it mounted on the base of the control panel instead of on the control panel top.

If you do a proper loop, then you will not need to worry if a button goes out, all the others go out. Take a look at my diagram below. Wiring the switches in parallel is what you want to do. Obviously, if none of the buttons/joystick work, then the main ground is broken. If one button doesn't work, but all others do, then it is easy to find where the break in the sequence is as long as you don't wire it in an irregular pattern. Ground the switches in the order that they are on the ipac. R, L, U, D, Sw1, Sw2, ... etc. Here is a quick ASCII picture of how I did it. There may be other ways, but this creates a ground loop with buttons in parallel.
 
                                                                            / To GROUND
                                                                           /

[M3talhead]

I'll add two cents, though it's painfully obvious (I think), but I don't recall anyone having said this - and I think I read all posts here so far completely.

Following the ideas in the picture let me also suggest you use different color wire.  For example, I used black wire for my grounds, red wire on all the joystick connects to the IPAC, and green for the buttons.  That way if a button stops working, I check the green connectors first, then look at my grounds to make sure nothing's come loose.  It may sound nutty, but it does help.

You're absolutely right on the color bit. The only reason I stuck with red and black was because:

1) I'm a cheap bastard and didnt want to spend $.40 on another 3 feet of colored wire

2) I use a multimeter to test all my connections. Its faster this way.

[c64rulez]

I would recommend a couple of ground loops--that way if you have a bad connection you don't lose everything and its easier to track down the offending bad connection.

I also used this approach and used a commoning block. I connected each series of joysticks & buttons to this block. refer bottom left hand corner.

Was taking pictures of a hydrogen bomb internals not supposed to be censored ?

[Spaz Monkey]

Since we're answering wiring questions here, I have one.  Short story long, needed to replace the buttons, the signal wire (not the ground) connection snapped off at the microswitch and got pulled out at the 3x4 molex connector to my jamma harness.  Now, how do I plug the wire back into the male part of the connector?  I'm talking about the the actual male wire connector.

[M3talhead]

You'll probably just need to replace the molex pin. You can get them at just about any electronics store. If the pin is still good and has the barbs intact, it might just be as simple as (gently) bending the barb back out and reinserting it into the molex.

[javeryh]

So if I'm daisy chaining the grounds together should I wrap the 2 wires together and then stick it in the connector before crimping?  I can't do one at a time, right?

[danny_galaga]

yeah, youve got the idea. just to clarify something, it may be that youve got the idea that both ends of this daisy chain have to go somewhere. this isnt so. so long as one end is connected to the ground then it works. you can connect the other end of the chain too if you want for redundancy but electrically its not required as the circuit is made through the  COM- NO junction when you press the switch.

[javeryh]

So going from ground on the iPac to COM1 and COM1 to COM2 and COM2 to COM3 etc until the last COM which will only have a wire coming in but not out is the way to do it?

THANKS!

[brian23]

So going from ground on the iPac to COM1 and COM1 to COM2 and COM2 to COM3 etc until the last COM which will only have a wire coming in but not out is the way to do it?

THANKS!

I don't see why that wouldn't work. I did the reverse: Last microswitch goes to main ground on IPAC. If you want to add support for coin drops per se, you'll need to figure that into your wiring situation if you have a coin door. In all honesty though, I don't think it matters which direction the ground reaches the ipac.

[javeryh]

Good point.  I do have a coin door that I will also have to add to the loop somehow.  Maybe I'll just run that ground directly to the iPac as well...