Sega Genesis Controller Rotary Controller Mod

[Gedalya]

I've recently worked through creating a rotary controller using a Sega Genesis controller I had laying about. I have it finished albeit with a glitch or perhaps I wired it wrong. The info I found on making one of these was incomplete so I had to fill in the gaps. Is there anyone who has made one of these that can provide some feedback/answer some questions? Or even better yet, if you have one would you be so kind as to open it and post photos of the front and back of the PCB? Thanks in advance.

[Gedalya]

Does it matter if the rotary encoder is mechanical or digital?

[Machine]

I am curious how people like the Genesis to Jag rotary. I have had two, and thought they were not as good as the Jaguar controller rotary.

[Zerosquare]

Have you read this?

https://www.jagware.org/index.php?/topic/930-how-to-add-a-rotary-knob-to-your-jaguar-controller/

 

1 hour ago, Gedalya said:

Does it matter if the rotary encoder is mechanical or digital?

You need a mechanical encoder. Optical encoders won't work as-is (they need a more complex circuit).

Edited August 31, 2022 by Zerosquare

[Gedalya]

On 8/30/2022 at 11:46 PM, Zerosquare said:

Have you read this?

https://www.jagware.org/index.php?/topic/930-how-to-add-a-rotary-knob-to-your-jaguar-controller/

 

You need a mechanical encoder. Optical encoders won't work as-is (they need a more complex circuit).

Thank you! I bought and installed one. I'm still having an issue. I think my controller just isn't grounded right.

[Gedalya]

I think I am having an issue with grounding. I have attached an image from the PCB prior to wiring with color coding for where things are wired up, just the buttons though from this side. The mapping for the collors to the 15pin 3 row connector is as follows:

• Pin 2, red 
• Pin 3, green
• Pin 4, blue
• Pin 10, black, ground
   

The three wires for the actual rotary controller, specifically the two, east and west, are mapped to the following pins on the 15pin 3 row connector:

• Pin 11, yellow, east
• Pin 12, orange, west

The grounding for the rotary encoder is tied back to Pin 10.

My question on the grounding though, the YouTube video I watched indicated Pin 10 as ground. My own research suggests it should be Pin 9. Can anyone provide clarification. Does any thing stand out that is wrong?

Edited September 3, 2022 by Gedalya
adding additional information regarding wiring the encoder.

[Zerosquare]

Which controller is it? The PCB doesn't look familiar.

 

From your description, the wiring isn't correct, but I'd need pictures showing the whole PCB (both sides) to help you.

Edited September 3, 2022 by Zerosquare

[Gedalya]

3 minutes ago, Zerosquare said:

Which controller is it? The PCB doesn't look familiar.

 

From your description, the wiring isn't correct, but I'd need pictures showing the whole PCB (both sides) to help you.

I'll take some photos to reflect the whole PCB. Unfortunately what I found with the Genesis model 1650 controller is that there is a wide variation on PCB design. I know they are all functionally the same but I have three 1650s and all three of the PCBs look different.

[Gedalya]

Here is a photo of the PCB:

[Zerosquare]

Sorry, I completely forgot that you were using a Genesis controller. No wonder the PCB didn't look like the Jaguar one 🤦‍♂️

 

Thanks for the picture. Can you make a photo of the other side as well?

[Zerosquare]

Also, please link to the instructions you found.

[Gedalya]

I dare say there are no proper instructions. I saw this video which went over the process in broad strokes:

 

 

Here is a photo of the other side of the PCB (before I made changes):

Edited September 3, 2022 by Gedalya

[Gedalya]

These are photos of how it looks now:

Edited September 3, 2022 by Gedalya
adding second photo

[Gedalya]

I chose to use some black wiring to supplant what was already there (extra length) so I have created another photo, "computer enhanced" to reflect the correct colors for the button wiring.

[Zerosquare]

I've looked at it and I don't see how that could possibly work without extensive modifications to the circuit board.

 

Do you have some diodes (e.g. 1N4148)? I think some will be required.

[Zerosquare]

As a first test, you can try this:

- desolder all the wires going from the 15 pin connector to the PCB

- desolder the black wire from the center pin on the encoder

- solder the blue wire on the center pin on the encoder

 

The encoder should work (not the buttons). If the rotation is backwards, swap the orange and yellow wires with each other.

[Gedalya]

41 minutes ago, Zerosquare said:

As a first test, you can try this:

- desolder all the wires going from the 15 pin connector to the PCB

- desolder the black wire from the center pin on the encoder

- solder the blue wire on the center pin on the encoder

 

The encoder should work (not the buttons). If the rotation is backwards, swap the orange and yellow wires with each other.

Thank you! I will try that asap!

[Gedalya]

1 hour ago, Zerosquare said:

As a first test, you can try this:

- desolder all the wires going from the 15 pin connector to the PCB

- desolder the black wire from the center pin on the encoder

- solder the blue wire on the center pin on the encoder

 

The encoder should work (not the buttons). If the rotation is backwards, swap the orange and yellow wires with each other.

I had originally noted an issue between the rotary encoder and the button connected by the blue wire. Because of that and what you wrote I simply disconnected the black wire from the encoder ground (center) and detached the blue wire and then hooked up the blue wire on the encoder ground. The controller now works except for the button which used to be connected by the blue wire; so the rotary knob and two buttons work fine. Woot!!! I'm checking for diodes now.

Edited September 3, 2022 by Gedalya

[Gedalya]

@Zerosquare I have no diodes but I can order some if you think I need them, just let me know.

[Zerosquare]

Yes, you will need them. You will also need to remove all the components soldered on the PCB (IC, resistors and capacitor).

[Gedalya]

2 hours ago, Zerosquare said:

Yes, you will need them. You will also need to remove all the components soldered on the PCB (IC, resistors and capacitor).

Thank you! I will go ahead and do that today. How many diodes will I need? Is it possible to also wire the start button on the Genesis controller to be used as well? Specifically as the pause button on the Jag? The lack of a pause button stood out to me (after the fact) as an issue. The rotary encoder I have also has a push button quality that I don't believe is used; can that be wired also as a button? Options perhaps? Thanks again! Your are now in my top five fav AA members.

[Zerosquare]

Ten diodes should be more than enough.

 

Considering how the tracks on the PCB are laid out, it's easier to wire the Start button as Option, and the encoder button as Start. If you want the opposite, you'll have to cut tracks on the PCB.

[Zerosquare]

Once you have removed the components soldered on the PCB, please post of photo of the result (both sides) -- it will be easier to show where the diodes and wires should be soldered.

[Gedalya]

14 hours ago, Zerosquare said:

Ten diodes should be more than enough.

 

Considering how the tracks on the PCB are laid out, it's easier to wire the Start button as Option, and the encoder button as Start. If you want the opposite, you'll have to cut tracks on the PCB.

Just saw these messages, sorry for the slow reply. Thank you!

[Gedalya]

17 hours ago, Zerosquare said:

Once you have removed the components soldered on the PCB, please post of photo of the result (both sides) -- it will be easier to show where the diodes and wires should be soldered.

Here are the photos, two each for the front and back where one shows the whole side and the other is zoomed in (I left the green and red wires off when removing things):

Edited September 4, 2022 by Gedalya
added note