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Main => Main Forum => Topic started by: DillonFoulds on March 07, 2011, 12:24:35 am

Title: Interface Resistance Tolerance - *PING* Andy and Randy?
Post by: DillonFoulds on March 07, 2011, 12:24:35 am
I'm playing around with some controller modifications (re-wiring Nintendo, Sega, etc. controllers). I've removed the ICs, Capacitors, and resistors from a couple controllers, and rewired the buttons and traces to a female DB15 (VGA-type) connector, replacing the cord with the header.

Now when I push buttons on the controllers, my DMM is showing there's a bit of resistance in the connection. I'd assume it's happening at the button contacts, due to the nature of the buttons.

Is this resistance going to be an issue for something like an ipac or a keywiz? Do these devices require 0 resistance between the signal and ground lines, or is there tolerance for slight resistance?

I haven't measured the exact amount, but I can, if need be.
Title: Re: Button Resistance - *PING* Andy and Randy?
Post by: AndyWarne on March 07, 2011, 09:17:41 am
As long as the resistance is low, a few ohms, the buttons should be OK. But beware of the analog buttons on controllers, these of course will not work properly.

Andy
Title: Re: Button Resistance - *PING* Andy and Randy?
Post by: RandyT on March 07, 2011, 12:34:42 pm
I'm playing around with some controller modifications (re-wiring Nintendo, Sega, etc. controllers). I've removed the ICs, Capacitors, and resistors from a couple controllers, and rewired the buttons and traces to a female DB15 (VGA-type) connector, replacing the cord with the header.

Now when I push buttons on the controllers, my DMM is showing there's a bit of resistance in the connection. I'd assume it's happening at the button contacts, due to the nature of the buttons.

If you have any components on the board at all, and you have the ground line connected on the other side of them in the circuit, you may get some resistance.  Those impregnated rubber pads under the buttons are probably the biggest culprit, though.  Regardless, they should work fine.  There is a range of voltage which is recognized as a button press, and it would take quite a bit of resistance to not pull it down far enough to register.

RandyT
Title: Re: Button Resistance - *PING* Andy and Randy?
Post by: DillonFoulds on March 07, 2011, 01:23:20 pm
Thanks guys! I think a buddy has an ipac he's not using, I'll see if i can steal it for a test. I've got a GPWiz 40 in a cocktail as well that I'll maybe pull and see if it works. I'll let you guys know what I find out. I vaguely recall my DMM giving reads of about "300" non-descript numbers in the continuity test mode. I'll try to find exactly what that measurement is in ohms though.
Title: Re: Interface Resistance Tolerance - *PING* Andy and Randy?
Post by: DillonFoulds on March 07, 2011, 10:24:24 pm
On my DMM, I set it to 200ohms, and I get readings of anywhere from 50 to 180, depending on how hard I'm pushing the buttons.

Who would have guess after all these years, pushing the buttons harder actually makes -some- difference?

I wired up some buttons to the Ipac4 that I managed to borrow, and it looks like everything is working great! :)

Still going to test out my GPWiz40, before I make any final decisions.

Looks like it's working with both the IPAC4 and the GPWiz40. Conclusively I can say that slight resistance doesn't have any negative, nor adverse effects on either controller board having issues with slight resistance on the signal paths.

Buttons seem quite responsive, and easily playable.

For anyone curious, I'm recreating pat47200's MVGS thread here: http://forum.arcadecontrols.com/index.php?topic=100909.0 (http://forum.arcadecontrols.com/index.php?topic=100909.0)