First Generation Immersion PCB (2 part)?

[68hc11]

So I added a second analog input (Throttle) to my First Generation Immersion PCB and have that working.  I decided to go for broke and add the brake pedal too but this Immersion board did not have a connector populated, so I soldered that in but the new input doesn't work.

It appears that the second set of analog inputs also needs a chip (LM324) & a few other resistors to fully populate it.

The big question is, if I go to all this trouble will it actually work?  (Will it really read the second set of inputs?  The Immersion driver shows a third analog input for brake but the signal appears to float (and why doesn't it show a 4th input since it appears this board supports 4 analog inputs?).

It is clear looking at the cabinet wiring that all Need for Speed cabinets use a Nytric USB board (or GVRI/O) for analog gas and brake pedal inputs as well as some digital outputs (lamps).

Failing all of these hurdles is there another way to get the last analog in for the brake pedal easily?

Thanks,
mowerman

[BadMouth]

There is a way to wire both the gas and brake pots to the same input so they show up as one axis.
(got this image from a quick google search and is for a similar application, I'm assuming it is correct, but you would probably need different value resistors.  This is on the list of things I never seem to get around to trying)
EDIT: I DON'T THINK THE RESISTORS ARE NECESSARY


I'd still love to know if we could solder in some extra parts and get those extra axis though.
I sold my old immersion boards.  I bought two newer ones that I haven't messed with, but I don't think they have the extra axis either.

[BadMouth]

Here is where the pic is from.  I do not see any info regarding why 500 Ohm resistors were used, but it says larger values may deteriorate performance.
http://tigerheli.mameworld.info/encoder/pedals/aki/AKIdoc.html

I seem to remember some arcade cabs being wired this way without the resistors, but I could be remembering wrong.

EDIT: More info: http://tigerheli.mameworld.info/encoder/pedals/gunpowder/wiring.htm

[68hc11]

Sort of reminds me of the old hack for Pole Position Brakes where they would just solder a resistor in line with a switch based on the assumption that no one tapped the brakes but slammed them.

I would love a close up photo of a fully populated Immersion board (2 part version), I'm slowly working through mine drawing the schematics but it is already apparent that the second input is not identical to the first.  (maybe that is why the driver software only shows 3 analog displays?)

I'm also digging into the Nytric board, I may be able to work out the logic on this board (not much).  Basically it has 3 Octal latches, 4 Mosfets and a small address select.  Perhaps someone can figure out the USB communication.  I'm guessing it writes a byte or two for outputs & reads 2-4 analog inputs (10 bit) and maybe two more bytes of digital inputs.

Mowerman

[BadMouth]

I'd like to add a disclaimer to this thread concerning combining pedals into one axis.

Nearly all old games prefer having them combined, BUT......

Model 2 emulator (the most important emulator) will not work properly with them combined.
You can work around it by enabling xinput and using x360ce (xbox360 pad emulator), but then you lose ffb.
You could also just map the gas pedal and then add a switch to the brake, but again that's not ideal.

Model 2 emulator is the odd one out.  I can't name a single other game or emulator that doesn't work with combined pedals.

[BadMouth]

I happened to be piddling around the basement and looked at the NOS immersion boards that I bought and never used.  They do have the Z axis.  Is this what your board looks like?

[BadMouth]

The reason for posting the pics was that if you had the same board only unpopulated, I could tell you what components are there.
(it is still partially unpopulated.)

It was a happy surprise that these have a Z axis.  It just dawned on me today that they also have a W axis.
I can has a clutch! ....and I already have two sets of happ 3 pedal setups.   
Guess I know which direction I'm going when/if I finally get around to working on my twin setup again.