Sega Shifter wiring

[Retro77]

Hi all,

I thought I would just check before starting. Is the RetroRepair microcontroller method for wiring still the best approach for connecting 3 switch shifters to PC?

Also, could someone provide the correct method. The thread below (right at bottom) has 2 different pinouts. I'm not sure which one is correct.

http://forum.arcadecontrols.com/index.php?topic=106709.0

Thanks

[PL1]

I thought I would just check before starting. Is the RetroRepair microcontroller method for wiring still the best approach for connecting 3 switch shifters to PC?

Check out baritonomarchetto's thread for several better approaches that also add a switch for "neutral".
- If you don't have a switch for neutral, one output is always active ==> one button is always pushed.
- That causes problems when trying to map other controls.
http://forum.arcadecontrols.com/index.php/topic,164398.0.html

If you want to use a 74LS138 demux, use this pinout/truth table.
- You only need to connect switch 1 or switch 2, not both since they are always in the same state.
- Connect ground to pins 4 and 5.  Connect 5v to pin 6.  (Enable)
http://forum.arcadecontrols.com/index.php/topic,164398.msg1731869.html#msg1731869



If you want a more simple setup, use this wiring diagram with the indicated changes.

If you want to add a "Neutral" switch and LED indicator to the wiring-only diagram, insert an SPDT switch between ground and switch 3 "IN". (COM)
- SPDT COM to ground.
- SPDT NC to switch 3 "IN".
- SPDT NO to LED, current limiting resistor, and 5v.

Scott

[Retro77]

Thanks again for the help, Scott.

I was going to use the 74LS138 demux following the diagram posted by Badmouth (I think).


Is there a different wiring diagram using only switches 1 and 3? Also, would the wiring in the shifter need to be changed?

I was going to use some spare ports on an A-Pac instead of the I-Pac on the drawing. I was going to pull the 5v from a PacDrive.

Edit: I DID IT!!!!! 

Now I need to work out how to sync up the VR buttons with Daytona

Cheers all

[PL1]

I was going to use the 74LS138 demux following the diagram posted by Badmouth (I think).

The problem with that version (shown below) is that there is no "neutral" option with that setup.  One output is always low (button pressed) unless you add a "neutral" rocker/toggle/slide switch for the 5v going to pin 6.
-  When the switch is open, there is no 5v on pin 6 (Input E3 = low) ==> line 3 of the truth table, all outputs are high. (buttons not pressed)

Is there a different wiring diagram using only switches 1 and 3? Also, would the wiring in the shifter need to be changed?

If you're asking if there is a wiring-only (no 74LS138) version that uses only switches 1 and 3, then the answer is no.

If you're asking if there is a wiring diagram for baritonomarchetto's 74LS138 truth table (above) like this one Badmouth posted, neither baritonomarchetto nor I made one.
- You would use the same connections for pins 4, 5, 6, 8, and 16.
- The difference is the inputs on pins 1, 2, and 3 and the outputs on pins 7, 9, 10, and 11 (instead of 9, 10, 13, and 14) going to the encoder.
- The truth table above tells you which switch goes to which input and which output goes to which encoder input.

I was going to use some spare ports on an A-Pac instead of the I-Pac on the drawing. I was going to pull the 5v from a PacDrive.

Sounds good.   


Scott

[Retro77]

I have it working now. I connected the wires as per your drawing above. It seems to work great so far.

I haven't come across any config issues yet. But I am sure they will crop up at some point