Build Your Own Arcade Controls Forum

Main => Main Forum => Topic started by: coasternuts on July 19, 2006, 09:47:04 am

Title: Proper grounding
Post by: coasternuts on July 19, 2006, 09:47:04 am

Is this an acceptable way to ground?  The following is an Ultimarc TB, a 4-way joy, 8 buttons, and Opti-Wiz and GP-Wiz. (Picture updated to include trackball grounds.)

I wanted the "mouse" buttons for the opti-wiz.   The different "greys" are just to represent groupings.

The reason I ask is that I rewired my panel to get off of swappables DB25 cables to each panel having it's own encoder.  And of course, it doesn't work.  The Joystick and buttons registered with no problem, but the Opti-wiz had a problem when installing.  The mouse pointer wouldn't move, and the mouse buttons wouldn't register.  The HID Compiant mouse was found, so I suspect the encoder is working and I have a short.  So I did a continuity test on the mouse buttons and then I noticed Windows registering the mouse events.  So I detached the panel and did more continuity tests to find out there is always continuity through all switches all the time.  I am using IDE header on a No-solder opti-wiz/gp-wiz. 

Is there a better way to test shorts other than continuity?

Any help is appreciated.  Thanks.

Title: Re: Proper grounding
Post by: coasternuts on July 19, 2006, 08:22:20 pm

Another question?

Can I run the same switch simultaneously to the opti-wiz and the gp-wiz?

Wired like so:

Title: Re: Proper grounding
Post by: hanelyp on July 19, 2006, 11:35:23 pm

Quote from: coasternuts on July 19, 2006, 09:47:04 am

Is there a better way to test shorts other than continuity?

Tests for continuity might be thrown off by the resistor pull up in the encoder.  (I'm assuming 1 line/button, no matrix)  You might try measuring voltage at either side of the switch while the circuit is powered.  Just be carefull about bridging leads with your probe.
One side should remain near ground all the time, the other a logic high unless the button is pressed.

Title: Re: Proper grounding
Post by: MYX on July 20, 2006, 08:29:20 am

I can not speak to the safety of wireing a button to both devices. Do not know why you would do that, but hey, it is not for me to make that call. If you are going to do that, you will want a diode on both ground wires so you do not get bumps from one device when using the other. You know, as I write this the more I am getting the feeling that I would just not recomend this at all. I am no expert, but it just seems like a bad idea.

Title: Re: Proper grounding
Post by: coasternuts on July 21, 2006, 12:13:47 am

My original intent was to have control buttons("fire", "jump") for the GP-Wiz and mouse buttons for the OS from the Opti-Wiz.

But based on MYX's comment, I suppose the mouse buttons could be the control buttons. Seems obvious now.  Der.

The other problem I am having is interfacing the GP-Wiz with the Ultimarc trackball.  Randy is working with me on this issue.  I'll post my results when I have them.

Thanks.

Title: Re: Proper grounding
Post by: MYX on July 21, 2006, 08:23:02 am

Randy rocks.


That's all I can say.

Title: Re: Proper grounding
Post by: coasternuts on July 27, 2006, 01:21:59 pm

Yes Randy rocks!  It turns out that if you use an Ultimarc Trackball with the Opti-Wiz then you need to place a 1K ohm resistor between the +5 and the data lines. 

Just thought I would reply in case others end up with the same issue.

Thanks Randy!

Title: Re: Proper grounding
Post by: lettuce on July 27, 2006, 03:25:26 pm

So i take it all the grounds/COM for buttons and joystick on the CP go to the ground terminal on a I-PAC too?? If So what else can be grounded to this terminal??