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Atari Steering Wheel - How many teeth for an encoder wheel?
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u_rebelscum:

--- Quote from: leapinlew on June 12, 2006, 11:04:27 pm ---Anyone have any idea what the optimal amount of teeth are?

--- End quote ---

If there was a single number of teeth that would work perfect for everything, it would have been found and posted all over this site. :D

Reasons why there is no one perfect number:


* Differences in number in original hardward,
* Gearing (if any) in original hardward,
* Differences in number of polling per tooth (1, 2 or 4) in original hardware (all current PC hardware do 4 per AFAIK),
* The sensitivity, accuracy, and max speed of the PC mouse hardware,
* Differences in mame's driver analog default sensitivity setting (which is usually set by author's mouse sensitive, aka number teeth),
* Differences in windows drivers and driver settings,
* Differences in PC's number of teeth per rotation, and
* Differences in distance between hacked sensors.
That last one is "minor", but can cause situations such as 300 teeth are perfect for person A but not work for person B, while 303 perfect for person B while work okay except cause problems at high speeds for person A.

The second to last actually isn't exactly related, but causes the similar problem of no single value for mame's analog sensitivity.

The two before that theoretically should help by adding a range of number of teeth, but in practice just confuse the issue, make it harder to compare tests from different people, and cause other problems with normal hardware.

All in all, the current "best practice" falls in one of two schools.
A) Get the original numbers for a specific game and try to copy them.  This depends on which game is modeled, and isn't perfect for other games, of course.
B) Try to get the highest number of teeth possible before reaching the limits of the PC sensors hardware & driver.  This depends on the hardware being hacked and if it's straight shaft, geared, or ball-to-roller (TB).  Then adjust mame's analog sensitivity for each game to try to match the original feel.


From the sound of it, you're going school B), and your sensor minimun width limit falls between 300 & 600 teeth (unless 600 teeth is under your printers effective minimun size limit).  If 300 works at high speed, I suggest just sticking with it and adjusting mame's analog sensitivity.

My 2 cents.
leapinlew:
Thanks - I am sticking with 300....

I was primarily asking how many teeth because of a couple reasons.

1. I didn't know if it was a number like 58 or a number like 1,500. I didn't want to reinvent the wheel here - pun intended
2. I don't know what the hell I'm doing. I did some trial and error and got decent results.

I'll adjust the settings in mame. I'm hoping it'll be ok.
u_rebelscum:

--- Quote from: leapinlew on June 13, 2006, 07:27:55 pm ---Thanks - I am sticking with 300....

I was primarily asking how many teeth because of a couple reasons.

1. I didn't know if it was a number like 58 or a number like 1,500. I didn't want to reinvent the wheel here - pun intended
2. I don't know what the hell I'm doing....
--- End quote ---


Yes, very understandable.  Usually the question is asked in the opposite direction:
"What is the perfect mame analog sensitivity setting (for all game's with xyz device)?", which is why you probably didn't find an answer in the search.


--- Quote ---I did some trial and error and got decent results.
--- End quote ---

The theory I wrote is nice, but trial & error works wonders.  However as you said, why reinvent the wheel if not needed. ;) 


--- Quote ---I'll adjust the settings in mame. I'm hoping it'll be ok.
--- End quote ---

Could you let us know how things go after you try it for a while on a few games?  It would be great to hear how well it works out in the long run.

Good luck!
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