IPAC LEDs and cvj

[hmy1]

Are the IPAC inputs 1B7, 1B8, and 2B7 supposed to register if the LED's are active? That's what I'm seeing in the IPAC's test mode (and my programs) when the num, scroll, or caps locks are enabled. A lot c's, v's, and j's.

I know these pins are bi-directional, but because of these spurious keys I guess I have to disable these keys in my programs. I'm also guessing that using these pins as both LED outputs and button inputs is out of the question? Or am I doing something wrong?

Thanks,
Howard

[Tiger-Heli]

Are the IPAC inputs 1B7, 1B8, and 2B7 supposed to register if the LED's are active? That's what I'm seeing in the IPAC's test mode (and my programs) when the num, scroll, or caps locks are enabled. A lot c's, v's, and j's.

I know these pins are bi-directional, but because of these spurious keys I guess I have to disable these keys in my programs. I'm also guessing that using these pins as both LED outputs and button inputs is out of the question? Or am I doing something wrong?

Thanks,
Howard

I didn't quite follow your question, unless you mean with a pass-thru keyboard, in which case I'm not sure.

Here's what I am sure of:  The LED's should flash to reflect the status of the keyboard port LED's as follows:

Num Lock - P1 Button 8
Caps Lock - P1 Button 7
Scroll Lock - P2 Button 7

The LED that is wired to P1Button 8 will also flash whenever P1Button8 is pressed during gameplay.  You can minimize the effect of this by assigning P1Button8 as Start1, and assigning the Start1 terminal to an action input.

The pins should work as both button inputs and LED outputs but the wiring is not straight forward.  For the inputs, you wire just like any other button input.  For the LED's you wire from a +5V source, either on the I-PAC LED header, or the motherboard PS, through a LOW CURRENT LED and a series voltage dropping resistor, and back to the P1B8 (P1B7, P2B7, etc.) terminal.

Also, see http://www.fraggersxtreme.com/arcadepanels/encoder/#I-PAC LED Considerations

[hmy1]

Sorry, to clarify: I was testing my IPAC and did not have 1P7, 1P8, and 2P7 connected to anything. I observed that if a program activated any of the LEDs (or if I did so myself via an attached keyboard), I would get these spurious c, v, and j's registering.

I had an offline conversation with Andy (great guy) yesterday and we suspect the culprit is the 6' DB25 cable I'm using to connect my IPAC to my swappable CPs. The long twisted wires could create a capacitance effect that may result in the spurious inputs.

When I connected my LEDs and buttons and the problem went away. Works great. I am using 1B7, 1B8, and 2B7 as both LED outputs and button inputs.

My local Fry's didn't have any DB25 cables shorter than 6' when I was there last weekend. They may not carry any, in which case I'll make my own to test.

Howard

[Brad Lee]

Id say try it with as short of a cable as you can. Im using 50pr wire and havent experienced any of the problems like you say, or from the other threads about inconsistent/random problems of this nature

From my Ipac/Optipac to my wiring block is ~12"
From the wiring block to the amp connector(similar to db25 or centronics) is another ~12"
The 'tail' from my CP(ending in the other connecter) is another 12" of twisted & sheathed wire, before I split it up for individual connections to the joysticks and buttons

Thats a minimum of 3' of twisted 50pair wire, and aside from flaky buttons, Ive not had goofy problems