Question about Jakks Atari TV-Game mod

[nasachusetts]

Hello,
I am currently building an oversized Atari 2600 joystick for my sculpture class and have a question about wiring.  I am using microswitches which will be soldered to a Jakks Atari TV game joystick and wondering if anyone knows where to solder the ground wire to on the board.  Is there a specific location I should look for?  Here are some pics of the inside of it


I could also upload higher res photos if needed.  Thanks.

[BobA]

A good starting point would be the neg on your battery compartment.

[danny_galaga]

Do you mean a 'common' for the switches? Just follow the traces around and see if there is one. Might be easier to see if you take off all those yellow contacts. I know from hacking other controllers that sometimes not all the switches share a common. If in doubt, since there aren't many buttons, you can always just wire it up like for like, that is- two wires from the microswitch going directly to the two contact points for the corresponding switch on the pcb...

[nasachusetts]

Do you mean a 'common' for the switches? Just follow the traces around and see if there is one. Might be easier to see if you take off all those yellow contacts. I know from hacking other controllers that sometimes not all the switches share a common. If in doubt, since there aren't many buttons, you can always just wire it up like for like, that is- two wires from the microswitch going directly to the two contact points for the corresponding switch on the pcb...

Yes for the ground I meant common for the microswitch.  I was planning on soldering speaker wire directly from the "NO" points on the microswitch to the corresponding contact points under the yellow contacts.  I thought I had to daisychain all of the common wires to all the microswitches and then solder it to one point on the controller board.  So are you saying that I could, instead of daisychaining, just have separate common wires on each individual microswitch going to each contact on the board at the same point as the "NO" wires?

[RandyT]

You can only daisy-chain them if there is actually a common for all of the switches.  It seems unlikely that so few buttons would require a matrix, but you can't assume anything here.

The best thing would be to use a multi-meter set to continuity and see if all of the switch pads have at  least one side which is linked with all of the other switch pads.  If so, you can do the daisy chain thing.  Otherwise, you may have to mimic the wiring configuration of the pads on your physical switches, with a couple of wires each.

RandyT

[nasachusetts]

I don't have a multi-meter and I don't have time or money to buy one right now and I am not sure how to work one anyways.  I have to try to start wiring this tomorrow because it is due Monday.  I have wired a PSX controller before to make an arcade joystick before but there was much more documentation and walkthroughs to help me out. I guess I was assuming this would be exactly the same as that where as I daisy chained all common points on switches to one ground point on PCB board.  I have been trying to follow the traces around the buttons but am still clueless as to where the common point would be.  I uploaded a much clearer picture here http://img13.imageshack.us/img13/5796/dsc0003iyk.jpg
Does anyone have any good guess as to what I should do?
Otherwise I am just going to try to solder to random spots tomorrow and cross my fingers I guess;)
Thanks for all the help so far.

[BobA]

If the stick has 1 button then the traces show a common ground between the 4 joystick positions and the single button.  If you look at the 3 contacts bottom for your joystick in the pic you can see the trace that connects all 3 it also goes up and connects the button and the other contact.  This is the common. 

[RandyT]

Maybe this will help.

[nasachusetts]

Thanks for the info!  I feel a lot less lost now.  
One more question, should I wire the 'NO' wires to each point you numbered yellow on the pic or to the actual contact switch itself or does it matter?
Much appreciated for the visual aid.

[RandyT]

Thanks for the info!  I feel a lot less lost now.  
One more question, should I wire the 'NO' wires to each point you numbered yellow on the pic or to the actual contact switch itself or does it matter?
Much appreciated for the visual aid.

Yes, the NO terminals go to the yellow spots.

[danny_galaga]

I think it looks like there will be five switches? The difference between daisy chaining or not will be 4 wires. Not a lot extra to do. If you aren't sure, just go like for like- two wires per switch and forget about a common (",)

[RandyT]

I think it looks like there will be five switches? The difference between daisy chaining or not will be 4 wires. Not a lot extra to do. If you aren't sure, just go like for like- two wires per switch and forget about a common (",)

It's pretty clear from the last photo that doing it that way would be unnecessary.

[danny_galaga]

I think it looks like there will be five switches? The difference between daisy chaining or not will be 4 wires. Not a lot extra to do. If you aren't sure, just go like for like- two wires per switch and forget about a common (",)

It's pretty clear from the last photo that doing it that way would be unnecessary.

Ha! I hadn't even noticed that last pic! As you were...