Sega Monaco GP cockpit pedal

[dramaone]

I'm replacing the opto's on the pedal mechanism and im a bit confused by what they do.


With the steering wheel it was a straight replacement of side by side optos like
https://www.ultimarc.com/images/vanewhl.jpg

With the pedal,rather than side by side opto's they are on top of eachother and as you press the pedal a piece of thin plastic moves in between them.
The plastic has two holes cut out, a small hole for when it passes the bottom opto and then a second longer hole  passes through the second opto to its full extend.

https://dl.dropboxusercontent.com/u/3208063/20161229_182938.jpg

All seems ok but then I'm thinking why does it have two staged switches?
If you look at 7min08 on this clip

you can see the original pedal with original logic board game and it seems to have two speeds, first opto speed 1, second opto full speed.

Is this what is happening?

I cant get my head around this.
Is it basically two switch points that then send data out as one, since there are only four cables coming out of the original pedal opto board so im guessing they + - and two data?

The cab is going to run the sega monaco remake and other 360 wheel games and so is this double opto unnecessary?

https://dl.dropboxusercontent.com/u/3208063/20161208_212544.jpg
https://dl.dropboxusercontent.com/u/3208063/20161229_185517.jpg
https://dl.dropboxusercontent.com/u/3208063/20161229_182938.jpg
https://dl.dropboxusercontent.com/u/3208063/20161228_133822.jpg
https://dl.dropboxusercontent.com/u/3208063/20161228_174755.jpg

[dramaone]

I'm also unsure if mame or monaco remake can handle an optical input for acc pedal so do you think it is worth progressing or
just replace with a Happ acc/brake pot set instead?

[dramaone]

sacked off the optical acc pedal and used a pedal/brake set with pots, hooked up to a u-hid nano, sharing the plus and negative with the wheel.

all good

[Andrela]

would you be interested to sell the opto boards that you removed from your monaco f you still have?  Mine is missing them and inam trying to get it going with the original circuit.  Thanks

[pixel]

FYI - Games like  Monaco GP,  Sega's  Turbo,  and some others that use the same kind of setup...

 Are not full analog.   By using two optos,  and a sliding gate.. they can get like 4 states.

 0 / 0  = Off
 1 / 0  = Low  Speed
 1 / 1  = Mid   Speed
 0 / 1  = High  Speed

 Theoretical:

  1 / 1  = Full   Speed

 Its been a long while since I had to sell my Sega Turbo off       I believe it had 3 main speeds and an off state...  for a total of 4 states.

 For the most part, most never would notice the lack of gradation... due to the games build in acceleration curve, as well as the 2 way gear shifter...
which brings that to 6 main speeds that the can can travel + any programmed acceleration / deceleration to blend things together.


 Interestingly enough,  TX-1  also used Optical pedals  (both gas and brake)  ...but... they used a rotary encoder disc. 
The same optical encoder discs as you see on the Tron / Discs of Tron spinner.   I believe it simply counted the positions,  and auto-calibrated if / as needed.

[Andrela]

Thank you Pixel.  Very informative.  I thought that monaco only had 2 speeds.  After looking at the blank plate, it shows the 4 stats as you described.