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Main => Driving & Racing Cabinets => Topic started by: tony.silveira on November 05, 2010, 01:45:47 am

Title: pedals hack - help needed
Post by: tony.silveira on November 05, 2010, 01:45:47 am
yhi all,

just finished a round of playing some driving games, using buttons as gas/brake.  not so much fun so i dug out my old mad catz mc2 racing wheel/pedal combo and i'm going to try and hack the pedals to use on my cab.

i took the base off of the pedals and see two pots in there, one each for the gas and brake.

gas pot has the following wires (location when looking at the BACK of the pot):

1. blue (center) - straight to the end 9 pin connector
2. black (left) - runs to brake pot wire #1 white
3. red (right) - runs to brake pot wire #3 brown

brake pot has the following wires:

1. white (right) - straight to the end 9 pin connector
2. yellow (center) - straight to the end 9 pin connector
3. brown (left) - straight to the end 9 pin connector

and that's where i need some help; which pin/wire measures the analogue value?  do i need to feed them power and if so, how?  can i simply hack the wiring into my spinners/trackball (i have two spinners / one trackball)?

the end cable is a 9 pin connector but since only 4 wires make it out, i could hack this easily into an s-video male/female connector to have the pedals easily stored and pulled out when i need them.

anyone out there do something similar and have any advice for me?

many thanks
Title: Re: pedals hack - help needed
Post by: SavannahLion on November 05, 2010, 04:13:19 am
gas pot has the following wires (location when looking at the BACK of the pot):

1. blue (center) - straight to the end 9 pin connector
2. black (left) - runs to brake pot wire #1 white
3. red (right) - runs to brake pot wire #3 brown

brake pot has the following wires:

1. white (right) - straight to the end 9 pin connector
2. yellow (center) - straight to the end 9 pin connector
3. brown (left) - straight to the end 9 pin connector

and that's where i need some help; which pin/wire measures the analogue value?

The center of each pot (blue and yellow respectively).

Quote
 do i need to feed them power and if so, how?

Depends on your setup, but generally speaking it would be either through the "right" or "left" of each pot. The remaining "right" or "left" would be tied to ground and the center would be used to get your reading. You may have to cut one of the wire "pairs" depending on the configuration. See below for a link on what I mean.

Quote
 can i simply hack the wiring into my spinners/trackball (i have two spinners / one trackball)?

Not directly, no. Unless the spinners are limited rotation spinners (like the Atari 2600 paddles which used pots) it won't work. Your spinners (and trackball) most likely use a disk with slots (or some variation) to give "blips" or rotational value. The computer can derive relative values if it knows the previous value. Nothing at all like a pot.

The easiest way to handle that is to hack a USB controller that already leverages pots or simply buy one of the controller boards from someone like Ultimarc. Ultimarc sports full instructions (http://www.ultimarc.com/a-pac.html) on how to use pots with their board.
Title: Re: pedals hack - help needed
Post by: tony.silveira on November 05, 2010, 05:42:59 am
I really should stop asking questions when I'm tired.

thank you for the info.  I think I'll just strip everything out of the wheel, mount those boards into the pedal base.  that way, when plugged in, the machine will see it as a full steering wheel set up

thanks again!
Title: Re: pedals hack - help needed
Post by: BadMouth on November 05, 2010, 09:40:40 am
Should I add a pot wiring section to the driving cab thread?

Considered it, but didn't think it was specific enough to driving cabs.

I picked up an arcade clutch/brake/gas assembly (along with a pile of other hardware  ;D ), so it's a good time to get pics of orginal parts.
I haven't swapped out the pots yet, because I'm not sure what interface I'll be using.

I need to add a section on how to wire in a sega 3-microswitch shifter too.
Title: Re: pedals hack - help needed
Post by: tony.silveira on November 06, 2010, 11:02:57 pm
decided to keep the wheel also.  after taking it apart, i think i'll be able to mod it so it's easily removable, like my current 360 degree wheel (check my sig for my machine project and scroll down to see the spinner that pops out for 360 degree racing).

it'll be a bit more complicated than my current wheel, what with the internal wiring that runs thru the shaft.  there are 19 wires that come thru, the exact pin count of an hdmi cable.  so i'll remove the wheel, rewire it so an hdmi cable is hanging out and then on the slide out box, i'll have an hdmi female plug.  slide the box out into place, pop the wheel on the shaft, plug the cable into the box.

so my slide out box will be wider and have two shafts on it, one for 360 degree racing, the other for 270 degree games (with the pedals working on each).

i'll update my project page whenever i get around to doing this.

thanks for the input!