DIY SNES -> NeoGeo DB15 adapter

Joined
Nov 24, 2018
Posts
8
Hi all,

If anybody else is working on a MVS consolization project, they might be interested in the project/code I've just posted to GitHub, which allows you to interface a SNES controller to a DB15 socket.

https://github.com/robinhedwards/SNES-to-NeoGeo

(can't figure out how to post an image here - maybe I'm too new.... :confused:)

I think I saw a commercial product that does this it was about £30 - but I'm sure I'm not the only one that enjoys building stuff like this themselves.

I put this together for about a fiver, since I had most of the bits already (all except the SNES female socket, which I got on eBay for about £2).

The main advantage over other approaches is that it leaves the SNES controller pristine, so I can still use it on my SNES.

Next step, 3d printed case, and possible a proper PCB since I'm going to need two of these...

Robin
 

GohanX

Horrible Goose
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12,490
That's pretty sweet! I made one of these a while back but threw it into a little project box. Yours is much more elegant.
 

massimiliano

ネオジオ,
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great, thanks for sharing! just curious, any theoretical delay? if you are putting together a PCB set and willing to sell a pair... I'm in!
 
Joined
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great, thanks for sharing! just curious, any theoretical delay? if you are putting together a PCB set and willing to sell a pair... I'm in!

I'm polling the snes controller at 200Hz, so there's a delay of 5 milliseconds at the moment. I think I could increase the polling rate and get the delay down to a millisecond or so, but I was being conservative, since a real snes normally polls its controller once per frame (50/60Hz). I think in practice the internal circuitry of the (original nintendo) controllers is very simple and would be quite happy to be polled at 1000Hz. I'll do some experiments!

I'm willing to consider making some for other members as long as there is enough interest to justify a small PCB run to make them easier to assemble. Post here is you are interested?

At the moment I've only tested it on my semi-consolized MVS, so I'd want to do a bit more testing before I'd be happy to sell them.

Is there anybody in the UK who would be willing to help me test the device on their MVS? The DB15 female connector is a standard one, rather than the deeper AES DB15 ports.

Robin
 
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JoeAwesome

I survived Secret Santa, It wasn't Easy.,
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They'll probably be a few people with interest, but if you're looking for a good turnout, post what you think a price range for cost is before shipping, imo.
 

fenikso

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I'd be down for two, in the say, $15 range...
 

Jonap

Mega Shock!!
Joined
Oct 10, 2006
Posts
100
Hi all,

If anybody else is working on a MVS consolization project, they might be interested in the project/code I've just posted to GitHub, which allows you to interface a SNES controller to a DB15 socket.

https://github.com/robinhedwards/SNES-to-NeoGeo

(can't figure out how to post an image here - maybe I'm too new.... :confused:)

I think I saw a commercial product that does this it was about £30 - but I'm sure I'm not the only one that enjoys building stuff like this themselves.

I put this together for about a fiver, since I had most of the bits already (all except the SNES female socket, which I got on eBay for about £2).

The main advantage over other approaches is that it leaves the SNES controller pristine, so I can still use it on my SNES.

Next step, 3d printed case, and possible a proper PCB since I'm going to need two of these...

Robin

Thanks for 3d designs!, where i can found the pcb gerbers and material list?.
 

DaisyAge

Galford's Armourer
Joined
Jun 10, 2018
Posts
457
Nope it should be good to go. You need the 5v version as the MVS give 5v through the controller ports.
 

davidmorom

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Sep 4, 2020
Posts
16
Hi everyone! Is very nice to see other people also making thier own designs. I decided to make custom SNES-MVS adapter and MVS Supergun after finding both of them pretty expensive (much more than the 20 bucks I paid for a MV1ACHX board in acceptable condition in Aliexpress).

My adapter is based on a Microchip PIC18 Microcontroller, and samples the SNES pad at 2KHz, so there is virtually no lag. It consumes only about 1mA, including the SNES pad. I also implemented an autofire feature, that can be individually enabled on each button, and the repeating rate can also be changed, by using the L and R triggers (this is a very nice feature for games such Metal Slug).

Here are a couple of pictures of my PCBs:

1.jpg
2.jpg
3.jpg

If someone is interested, I could share the PCB desing files and the MCU firmware.
 
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Gentlegamer

Sakura's Bank Manager
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728
I use an adapter for the Hori Fighting Commander but would LOVE a SNES adapter
 

Jonap

Mega Shock!!
Joined
Oct 10, 2006
Posts
100
Hi everyone! Is very nice to see other people also making thier own designs. I decided to make custom SNES-MVS adapter and MVS Supergun after finding both of them pretty expensive (much more than the 20 bucks I paid for a MV1ACHX board in acceptable condition in Aliexpress).

My adapter is based on a Microchip PIC18 Microcontroller, and samples the SNES pad at 2KHz, so there is virtually no lag. It consumes only about 1mA, including the SNES pad. I also implemented an autofire feature, that can be individually enabled on each button, and the repeating rate can also be changed, by using the L and R triggers (this is a very nice feature for games such Metal Slug).

Here are a couple of pictures of my PCBs:

View attachment 58203
View attachment 58204
View attachment 58205

If someone is interested, I could share the PCB desing files and the MCU firmware.

Wow very nice job friend! can you be kindly to share the designs of supergun and adapter snes to be able to do it ourself?

Thanks in advance!


PD: Some questions about supergun
-What Video type cable uses? dont have potentiometers to can regulate RGB and Sync?
-Power supply seems to be only +5v, audio then dont work on mvs boards?
 
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DaisyAge

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Jun 10, 2018
Posts
457
Looks like it's a 5v modded system which bypasses the op amp for audio. Probably a mini 8 din connector and cable. He probably has resistors in the cable head to attenuate to his tv but you could put pots instead.
 

city41

Gal Ageise's Demon
10 Year Member
Joined
Dec 27, 2010
Posts
2,065
Anyone know of the opposite adapter? I want to use my Neo stick on my GBA Consolizer. I built a converter from an old pad, but it's bulky as hell.
 

davidmorom

n00b
Joined
Sep 4, 2020
Posts
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Wow very nice job friend! can you be kindly to share the designs of supergun and adapter snes to be able to do it ourself?

Thanks in advance!


PD: Some questions about supergun
-What Video type cable uses? dont have potentiometers to can regulate RGB and Sync?
-Power supply seems to be only +5v, audio then dont work on mvs boards?

Looks like it's a 5v modded system which bypasses the op amp for audio. Probably a mini 8 din connector and cable. He probably has resistors in the cable head to attenuate to his tv but you could put pots instead.

Yes, it is a 5V modded system. I fed 5V to the jamma 12V line, and in the MVS board, I replaced the power Amp with a NPN common-emiter amplifier stage. I also remove the pot and some capacitors, as they are not needed anymore.

20201107_121823.jpg

Regarding video, I use a minidin8 connector, with the same pinout the framemeister uses. The resistors are fixed value ones, on the supergun board. I used a scope to determine the correct value to attenuate the signals to 0.7vpp, which in my case resulted to be 120ohm. Other boards may require another values, but as this is the only board I use, I don't need the pots.

Here are the schematics and the PCB layouts in Eagle format. For the SNES adapter, the firmware HEX file needs to be burned onto a PIC18F2550 microcontroller (very oversized MCU for this purpose, but is what I had in hand). By pressing L trigger and A, B, X or Y button at the same time, autofire is enabled or disabled on that button. By pressing R trigger, the repeating rate of the autofire feature can be changed to five posible values between 16 to 2 times per second.

https://mega.nz/file/T0p2ARiS#L4MRmXfv4UrqirzOYjShn_TToC7l68N9Nt4CXqaLiI4

Hope this is useful to someone.
 
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Jonap

Mega Shock!!
Joined
Oct 10, 2006
Posts
100
Yes, it is a 5V modded system. I fed 5V to the jamma 12V line, and in the MVS board, I replaced the power Amp with a NPN common-emiter amplifier stage. I also remove the pot and some capacitors, as they are not needed anymore.

View attachment 58222

Regarding video, I use a minidin8 connector, with the same pinout the framemeister uses. The resistors are fixed value ones, on the supergun board. I used a scope to determine the correct value to attenuate the signals to 0.7vpp, which in my case resulted to be 120ohm. Other boards may require another values, but as this is the only board I use, I don't need the pots.

Here are the schematics and the PCB layouts in Eagle format. For the SNES adapter, the firmware HEX file needs to be burned onto a PIC18F2550 microcontroller (very oversized MCU for this purpose, but is what I had in hand). By pressing L trigger and A, B, X or Y button at the same time, autofire is enabled or disabled on that button. By pressing R trigger, the repeating rate of the autofire feature can be changed to five posible values between 16 to 2 times per second.

https://mega.nz/file/T0p2ARiS#L4MRmXfv4UrqirzOYjShn_TToC7l68N9Nt4CXqaLiI4

Hope this is useful to someone.

I greatly appreciate your contribution David, I hope not to bother with my request.

-AMP:
----------
Do all MVS boards have the same amplification scheme?

With this pcb I understand that by feeding the 12v pin of the jamma with 5v we will have audio from the pin of the jamma itself, right?

-Supergun PCB:
-------------------------
I know it's more than I can ask for, but would be so kind as to modify the layout to:

> 4 pin molex conector power supply with original + 5v / + 12v to jamma
> Slot for x4 rm065 potentiometers for RGB / S signals.
> Gerber files?

s-l400.jpg

61eDUrdgPDL._SL1000_.jpg


It is to be able to have a versatile supergun for beginners that does not require modifying the original MVS.
 
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davidmorom

n00b
Joined
Sep 4, 2020
Posts
16
I greatly appreciate your contribution David, I hope not to bother with my request.

-AMP:
----------
Do all MVS boards have the same amplification scheme?

With this pcb I understand that by feeding the 12v pin of the jamma with 5v we will have audio from the pin of the jamma itself, right?

-Supergun PCB:
-------------------------
I know it's more than I can ask for, but would be so kind as to modify the layout to:

> 4 pin molex conector power supply with original + 5v / + 12v to jamma
> Slot for x4 rm065 potentiometers for RGB / S signals.
> Gerber files?

It is to be able to have a versatile supergun for beginners that does not require modifying the original MVS.

Hi Jonap! You are right, I just feed 5V on both jamma power lines (5V and 12V), and I just get an audio signal on pin 10 that can be directly connected to the TV set or a digitizer like OSSC or framemeister (but not directly to the speaker of a cabinet, for that the power amplifier is required). The amplification circuit of the MVS boards is similar, but not all of them uses the same power amp. My PCB is only valid for boards that use the TA8201AK (all MV1A and MV1B boards and variants), but other boards like MV1C and MV1F and variants, uses a different power amp, so my PCB can't be used directly.

Regarding your request of modification, give me a few days to see if I can find some free time, and I would be pleased to help you.
 

Jonap

Mega Shock!!
Joined
Oct 10, 2006
Posts
100
Hi Jonap! You are right, I just feed 5V on both jamma power lines (5V and 12V), and I just get an audio signal on pin 10 that can be directly connected to the TV set or a digitizer like OSSC or framemeister (but not directly to the speaker of a cabinet, for that the power amplifier is required). The amplification circuit of the MVS boards is similar, but not all of them uses the same power amp. My PCB is only valid for boards that use the TA8201AK (all MV1A and MV1B boards and variants), but other boards like MV1C and MV1F and variants, uses a different power amp, so my PCB can't be used directly.

Regarding your request of modification, give me a few days to see if I can find some free time, and I would be pleased to help you.


Thanks a lot for youre efforts and time
 

davidmorom

n00b
Joined
Sep 4, 2020
Posts
16
Hi again Jonap!

I've been working on the modifications you requested. I replaced the power connector with a 12v+5v 4 pin molex. Both 12v and 5v power lines are routed to the jamma edge trough a DPDT switch, so by turning it of you completely disconnect the power from the MVS board. I also added the potentiometers for the R, G, B and sync signals. Lastly, as you are going to use the output of the audio power amplifier, which output voltage level can be pretty high, I added a resistor divider on the audio signal line, to attenuate it by a factor of 10 to prevent damage to the receiving device (so you should set the audio potentiometer on the MVS board to its maximum position to get a correct audio level). Keep in mind that this modifications are UNTESTED, I've been careful, but I could made some mistakes. Please check the design (specially the power part) before using it.

I also generated Gerber and drills files for you, but as I make my PCBs at home, I've never used Gerber files before, so I am not sure if they are OK for sending them for production. Please, check this also.

https://mega.nz/file/b4pHxSja#oCzlF-5EyUC4uSKyBHiY1mN_U86AEVgeymKwRDJrYkw

Hope this is useful to you.
 

Jonap

Mega Shock!!
Joined
Oct 10, 2006
Posts
100
Hi again Jonap!

I've been working on the modifications you requested. I replaced the power connector with a 12v+5v 4 pin molex. Both 12v and 5v power lines are routed to the jamma edge trough a DPDT switch, so by turning it of you completely disconnect the power from the MVS board. I also added the potentiometers for the R, G, B and sync signals. Lastly, as you are going to use the output of the audio power amplifier, which output voltage level can be pretty high, I added a resistor divider on the audio signal line, to attenuate it by a factor of 10 to prevent damage to the receiving device (so you should set the audio potentiometer on the MVS board to its maximum position to get a correct audio level). Keep in mind that this modifications are UNTESTED, I've been careful, but I could made some mistakes. Please check the design (specially the power part) before using it.

I also generated Gerber and drills files for you, but as I make my PCBs at home, I've never used Gerber files before, so I am not sure if they are OK for sending them for production. Please, check this also.

https://mega.nz/file/b4pHxSja#oCzlF-5EyUC4uSKyBHiY1mN_U86AEVgeymKwRDJrYkw

Hope this is useful to you.
Great job David, I'm really grateful to you.

Some questions:

-Wich size of smd resistances and test buton use this board?

-The mini din 8 port of supergun i see its not standard, found a rgb cable with that pinout can be dificult, its my last request, I don't want to bother you anymore, can be possible to put a minidin 9 megadrive 2 standar, or din 8 megadrive 1 standar rgb port? its for can use easy and cheap RGB cables. you only need to put Sync signal in the megadrive composite pin and thats all.

-Looking over everything seems to be correct but ( maybe im wrong ) there is a possible fault with the potentiometers.

It should be an input pin, an output pin and a GND, on the board it seems that there is an output pin and two input pins but there is no GND?

The big pots work like this:
ZLwwO8N.png


Dont know pinout of RM065 smd pots but in the PCB sems to dont have GND pin i think.

-Finally with these switches they will serve me for power on right?

https://es.aliexpress.com/item/4000265256811.html?spm=a2g0o.cart.0.0.48793c00hzHjLD&mp=1

Thank you again!
 
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davidmorom

n00b
Joined
Sep 4, 2020
Posts
16
-Wich size of smd resistances and test buton use this board?

Resistors are 1206, and the test button is a momentary 6x6mm push switch, like these ones:
https://www.ebay.es/itm/100PCS-SPST-Mini-Micro-Momentary-Tactile-Push-PCB-Button-Switch-6x6x4-3mm-13mm/192069633566

-The mini din 8 port of supergun i see its not standard, found a rgb cable with that pinout can be dificult, its my last request, I don't want to bother you anymore, can be possible to put a minidin 9 megadrive 2 standar, or din 8 megadrive 1 standar rgb port? its for can use easy and cheap RGB cables. you only need to put Sync signal in the megadrive composite pin and thats all.

You can find the correct cable at retrogaming cables: https://www.retrogamingcables.co.uk/8PIN-MINI-DIN-TO-RGB-EUROSCART-TIM-WORTHINGTON-NES-RGB-ATARI-2600-HAS-SUPERGUN-Sega-Game-Gear-Philips-CDi-Colecovision-Intellivision-Panasonic-3DO

If you are not OK with this cable, I can change the connector with a MegaDrive 9 pin MiniDIN.

-Looking over everything seems to be correct but ( maybe im wrong ) there is a possible fault with the potentiometers.

You are right, in those cases you want to use the potentiometer as a 3-way voltage divider. But in this case, you just need a 2-way variable resistor, so one of the extremes of the potentiometer should be left unconnected (or shorted to the central terminal, which is electrically the same).


-Finally with these switches they will serve me for power on right?

They seem fine, but can't be 100% sure cause there are no information about the dimensions.
 
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