Posted by Marshall on 5, 2000 at 10:33 AM:
I recently purchased an Interact V3 steering wheel and am planning to convert the pedals from it for use with MAME. The pedals seem similar to the design used by MAD CATZ.
I plan to rewire the pedals similar to the approach shown on Lew's wheels, Wally's World or www.gunpowder.freeserve.co.uk/wheels/wiring.htm to use a DPDT switch to select between single-axis and dual-axis.
I cannot tell how the pedals are wired now. The first pin of each (brake and gas) pot is connected together and wired to a PCB in the wheel. The middle (wiper) terminal of each pot is connected separately and goes to the PCB, but they both seem to connect to pin 4 (ground) of the joystick port. The end pin of each pot is connected together and wired to the PCB in the wheel.
I have several questions:
1. In Outrun, using the keyboard, the brake lights come on when the ALT key is pressed. Using the pedals, the brake lights did not work, although the brake pedal did slow the car down. I assume this is because in single-axis mode, MAME does not know if the brake is being depressed or the gas is being released. Is this correct? For most MAME games would the pedals work better in dual-axis mode? Does anyone know which driving games used pots and which ones used microswitches for the pedals?
2. In wiring the pedals, I plan to use the circuit shown at gunpowder.com (see link) with the following changes. Since both of the pots turn the same direction, (CCW as pedal travel increases), I will move the blue wire of the DPDT switch to the right instead of the left end terminal of the gas pot. I also will wire to pin 1 instead of 9 and pin 3 instead of 11. This will put the gas pedal on J1X and the brake on J1Y in dual-axis, or both on J1Y in single axis. (I don't need J1X for the wheel as I will be using an optical wheel). Does anyone see a problem with this method?
3. Since I will still need an analog joystick for MAME (until I build my arcade joystick), I will use a splitter cable to attach the pedals. Would I then use "-joystick dual" to use the pedals in MAME?
4. Calibration in MAME should not be a problem, as MAME simply requires rotating the joystick through the full range of motion and pressing the ENTER key.
5. I may also want to use these pedals for flight sims in Windows 98. If I use the splitter cable and another joystick and single-axis mode, I should be able to calibrate it as a two-button, three-axis joystick. If I am not using another joystick, I have either a one-axis, or two-axis, zero-button joystick. Win 98 will not allow you to select this. I could wire a pushbutton microswitch as button 1 (only to calibrate the pedals), to allow calibration in single-axis mode. In dual-axis mode, I don't know if this would even help as Win 98's calibration is "Center joystick, press button, circle joystick, press button, center again, press button," and any idea of center position would be a poor guess at best. Is it a good idea to add a pushbutton, or does anyone have a better idea???
Thanks in advance,
Marshall