Wednesday, May 9, 2018

Building an SNES Controller

This was a fun little project that I intended to log in great detail but I just didn't really take enough pictures, so I realized too late that it's more of a "draw the rest of the fucking owl" situation. Oh well, here's what I ended up with, and I'll follow up with some info on how I got there:
My giant SNES pad with original pad for scale reference
It's a 6:1 scale SNES/SFC gamepad built from scratch. Unlike the other oversized gamepad projects floating around online, I don't have a 6-figure woodworking shop (and I'm not a good carpenter anyway), so I used manufactured arcade buttons instead of rigging up funky homegrown button/dpad mechanisms, and I built the internals using a breadboard and a couple of shift registers instead of padhacking an original SNES pad (those things are getting expensive these days).

I had originally planned to make the size an even 10:1 scale but after doing the math, I realized the resulting pad would be over 6 feet across and wouldn't be practical to actually use (i.e., like most of the other oversized gamepad projects floating around online). I had chosen 10:1 because SNES pad buttons are right at 10 mm in diameter and you can purchase humongous 100 mm arcade buttons on Amazon/eBay, but they also sell 60 mm buttons, which results in a much more reasonable 6:1 scale.
I found this dimensioned image online but it seems to have disappeared so I'll rehost it for others to benefit from.
Once I got the scale figured out, I cut the outline of the pad shape out of a piece of particle board I had left over from a previous project. I don't have a router and a circle jig, so I used a jigsaw and fashioned a compass out of a pencil and some string to draw the round parts:
For the internals, S/NES controllers are exceedingly simple, consisting of nothing but a couple of 8-bit shift registers. I happened to have 2 CD4021Bs lying around from a previous project and figured I'd give it a shot. This schematic shows up various places online and was very useful for getting everything wired up to my breadboard:
And here's what it looks like all wired up:
The only part I didn't make myself is the actual controller port plug, which I took from a newly manufactured SNES extension cable.

I used terminal blocks to make it easier to swap things out in the future and to reduce strain on the breadboard connections, which are the weakest link in the chain. The terminal blocks also came with bridges (the red-rubber thing on the one at the bottom-left of the image) that were useful when running voltage lines out to the button LEDs.

I left the back open and just built a little frame around the wiring. I may go back and put acrylic or another piece of wood over it, but I'm okay with it as is for now:
You can also see the L and R shoulder buttons, which are just the same 60 mm buttons used for the face buttons (the button sets come with 5 buttons and I ordered one additional one for a couple of extra bucks on eBay). The dpad buttons are also 60 mm buttons, but they're flat instead of convex:
Testing the button LEDs. You can get a good look at the flat dpad buttons. Still lacking some of the paint, as well.
It controls surprisingly well and is sort of like a Playstation controller with the separate directional pads. The start and select buttons are just regular ol' 30 mm arcade buttons. I would have liked to do something that looks a little more authentic but there just aren't any off-the-shelf long, skinny buttons.

Some day, I may go back and fabricate a small dpad to lay over the individual buttons and/or rig up something over the start/select buttons, but I doubt it, since they work fine already.

Anyway, here's my 3-yr old daughter and me playing some Donkey Kong Country on it:
She still doesn't really get video games, and her fine motor skills aren't really good enough for a standard-sized gamepad (which isn't really designed for her toddler-hands anyway), but she likes pushing the buttons on the oversized pad and having me control movement lets her focus on a single action, like jumping. I can also call out the color of the button she needs to press, which helps her work on her color mastery.

Anyway, that's it. If you have any questions, hit me up in the comments.


Thatman84 Emulation said...

Trully awesome project!
Gonna share this one :0

André Antunes da Cunha said...

That last image made me smile, awesome use of a nice work!

Hunter K. said...

@Andre Antunes da Cunha
Thanks! It was (and still is) a fun little project that I can share with my daughter :)

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