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idea for hacking gpwiz49 board to emulate analog shifter (Hard Drivin)
Major Rock Hardy:
So I collected a 4 speed microswitch shifter, triple pedal set, and now I want to play Hard Drivin'. AFAICT, there are two possible ways to go:
1. Play the upright version, but not use the clutch
2. Play the sitdown version, but somehow emulate the analog shifter using microswitches.
Well, #2 is the most appealing since I do have 3 pedals and I plan to use them. A thought came to me yesterday that I can use a GPwiz49 board to get the microswitch shifter to appear to MAME as an analog joystick (which is what is expected for sit-down Hard Drivin').
I envision working out what signals need to be sent to the GPwiz49 board to emulate the 49-way joystick positioning and wiring up some 5V discrete logic (maybe even a PAL or a GAL) to send those signals, using the microswitches as input bits. I haven't done any of the Karnaugh maps for the logic or anything, just wanted to throw the idea out there. I would assume the inputs would have to be de-bounced. Also, since the Hard Drivin sit down had a reverse gear, you could still use a 4 position shifter but add a Reverse button as another input to the discrete logic.
Am I nuts? Am I making this too complicated?
u_rebelscum:
Too complicated IMO.
I'd suggest trying to use mame's internal digital-to-analog input handling first, and see how well it works. Make sure mame's gear shift AD_stick sensitivity and return to center are set very high.
Hmm, mapping your gears might be the hard part. The gear switches are in the diagonals, correct? IOW, gear 1 (up left) is one switch, and gear 2 (down left) is another, gear 3 (up right) etc? If so, map* (OTTOH):
AD stick Y dec (up): gear1 not gear2 OR gear3 not gear4
AD stick Y inc (down): gear2 not gear1 OR gear4 not gear3
AD stick X dec (left): gear1 not gear3 OR gear2 not gear4
Ad stick X inc (right): gear3 not gear1 OR gear4 not gear2
This should work, but I haven't tested it from work. ;)
*To get ORs, enter, press button(s), wait more than ~1 second (until button(s) show in UI), enter, press other button(s). To get nots, press button twice in a row quickly (less than ~1/2 second). To get more than one button, press those buttons either at same time or very soon after each other (less than ~1/2 second).
brandon:
did you ever get this worked out? you use the PC gameport with a few resistors and diode to do what you want.. or hack a USB analog fightstick. for example, if the Y axis uses a 100k pot the 0 ohms might be left 50k is center and 100k is Right.. with some resistors hooked to the 4 switches on the shifter the positions of the axis could be simulated. I'm not really sure why Atari used an analog shifter in the first place.. seems like overkill...
SavannahLion:
--- Quote from: brandon on November 02, 2007, 05:29:16 pm ---I'm not really sure why Atari used an analog shifter in the first place.. seems like overkill...
--- End quote ---
Probably to better simulate a real car. I don't know how much of the shift Hard Drivin is picking up on, but I understand that a lot of effort went into simulating the dynamics of the car as accurately as possible. It would make sense to use an analog shifter rather than a switched one. Most real world manual cars aren't equipped with a slapstick or soft shifter.
Xiaou2:
Durability, Costs(?), and Ease on Operator maintenance.
Youd need 5 heavy duty switches... and because the way there is limited
space in there, the way that they are mounted is not an easy task. That
would also make changing a switch more difficult.
If a single switch failed... you would not be able to make the time limits
on the game. It would also be hard to for an Op to keep checking on
them.
The pot based shifters work amazingly well.. and are very durable. If a
pot goes bad, people will complain much more as it will take out
more than gear one at a time.
I used to have to work on these things... and I can say that the Daytona
Usa shifters, which used mini micro switches were always breaking
down. While I might have had to change the pots once in my 3yrs
service in Race Drivin.
Other thing to consider - is that they may have had the plan to
make a shifter plate upgrade in the future - adding more gears
into future revisions, or have other racing games using that same
hardware. I have to say, Its my favorite shifter. Its nice
snap lock feel as it goes into gear is beautiful. The motion
and throws (pivot points / leverages ) of the thing is great too.
Its also built like a tank, not failing easily, even under the most abusive situations.
I wish they would Fix mames shifter situation. Adding a MODE to add
"HELD DOWN BUTTON" so that a button is always on = Hi, and letting it
go = Low. While there are only a few keys on the keyboard that you
wouldnt mind being held down (caps lock, shift, insert?) one can easily
use Gamepad buttons without any windows issues when exiting.
Mames current situation does not know what the actual switch
position is (in many games). If you start mame with your shifter in low gear,
mame may think its in High gear. This does not happen in the real
machines, cause they do not use a phony Toggle mode.
They are wired to know which is which.