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| How to interface an ANALOG Race Drivin Shifter??? |
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| mark shaker:
Greetings, I bought an NOS shifter to the deluxe Race Drivin game, which I intended to use in a Sit Down MAME cabinet I'm building (well ... customizing). Anyway, much to my surprise the darn thing is analog. It doesn't have microswitches, it has 2 5K pots. The shifter is gated. Race Drivin determines the gear by the joystick position: 1|3|X ------- N|N|N ------- 2|4|R I know how to substituite 100 K pots, and wire the thing to a joystick port. But then what? Could MAME correctly interpite a joystick position as a gear? If not, is there any software than could translate a shift in joystick position to either a joystick button press or a keystroke??? Thanks for your help! - Mark P.S. There also seems to be an electric magnet in the base of the shifter. Does anyone have any idea what that was used for? |
| SirPoonga:
Two ways, first the cheap but crappy way, just hook directly to the correct pins on the gameport. The way I wuld do it, get a cheap usb joystick and take out it's pots. many controlers have 100k pots, but calibration with 5k pots should probably be fine, I think. |
| u_rebelscum:
It looks like the racedrivin driver (scr/drivers/harddriv.c) is set up with an analog joystick as the shifter :) ; your stick should be fine once you install it into windows. |
| Xiaou2:
The electromagnet was for locking the gears in place i believe. most operators either disabled this... or it just broke and they never bothered to repair it. |
| StephenH:
You could certainly use the POT inputs, by swapping 5K for 100K, and connect to the PCs Game Port, or a USB based Analog input. Also, you can build a A to D circuit, that would "turn on" digital outputs" at certain voltage levels. Assuming the Race Drivin Shifter pattern is 3X3 (Reverse plus 1-4), as follows: Assuming a +5V input to the pots, and the range the pots output was 0-5V, and assuming the "in gear areas" are symmetrical (as refered to pot positions), you would need three voltage comparators that turn on if the input voltage was between 0 and 1.66V, 1.67V and 3.33V and 3.33V and 5V, respectively per axis (6 comparators in all). Assuming the top is 0V and the bottom is 5V on the Y axis, and the Left is 0V and the right is 5V on the X axis. So, the voltage pattern of the gears is: 1st: When the X axis and Y axis voltage is between 0V and 1.66V 2nd: When the X axis voltage is between 0V and 1.66V and the Y axis voltage is between 3.33V and 5V. 3rd: When the X axis voltage is between 1.67V and 3.33V and the Y sxis voltage is between 0V and 1.66V. 4th: When the X axis voltage is between 1.67V and 3.33V and the Y voltage between 3.33V and 5V. Reverse: When both the X and Y axis voltages are between 3.33V and 5V. Neutral: When the Y Axis voltage is between 1.67V and 3.33V. The X Axis voltage does not matter. Once you have these comparators for the correct voltages, you then connect their outputs with AND gates, as above, and connect these AND gate outputs to your "gear keys" As for the magnet, it is a force feedback device to lock the shift position, if the clutch was not in. To implement this, you would need to get the voltage, and connect your analog clutch's pot (the other side, as you want it to be energised when the clutch is OUT), to a MOSFET or relay, and then connect that output to it and a power source of the correct voltage and current for the magnet. The other possibility is to modify the software to send this output or clutch position to the keyboard lights, or some time of parallel or USB port output, and connect the output to a relay or MOSFET controller, with the proper voltage and amperage power source. |
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