Arcade Stick Buildlog: Part 3

Last time, on arcade stick buildlog, we finished all of the outer components like the body, acrylic faceplate, wood blocks, and metal backplate. Now’s it’s time to wire everything up and then marvel at our new arcade stick.

Last Episode of Arcade Stick Buildlog...

First step is to prepare the buttons. Disassemble them by popping the tabs on the side in. You’ll notice that it’s made up of 3 parts: a body, a plunger, and a cover for the plunger.  You’ll also need those cutouts from the art that I mentioned way back in the 1st part.

Button Disassembled

Now the first step is to prepare the LEDs that I’ll be sticking into the button.

A certain drill, button, and LED.

It’s hard to see, but I used a pin vise drill to drill 2 small holes in the left and right side of the body of the button. This is for the legs for the 2 LEDs that I’ll stick in there.

The LEDs I got were some really bright ones with a high viewing angle off of eBay. They’re the kind with a flat top (hence the high viewing angle). I got pink, green, blue, and red ones (to match the PSX buttons).

LEDs in Buttons

After drilling your 4 holes, just stick the LEDs in like so. We’ll wire them up later.

Next, I highly suggest screwing the buttons into the stick’s body (just the body of the button, leave the plunger and cover for later) because you’ll need to screw them in really tightly (use hand tools) to prevent the buttons from rotating later.

Rotating buttons = misaligned art = (T^TT )

Next is to take those cutouts and trim them to fit onto the plunger. Make sure the button art is aligned with the button that should be in the body of the stick already. Then use white glue to glue the art onto the plunger.

Like so.

Then reassemble the button by putting the art-filled plunger and cover back onto the button.

Now we’re also going to prepare the Xbox360 board, since this stick will be dual-modded as well. Go get a Madcatz 4716 360 pad (I just bought it at Wal-Mart).

Sacrificial Madcatz Pad

Take it apart and pull out the pcb inside.

360 PCB

See those grey things? Be REALLY careful removing them, those 3 pins on the bottom may come off and then you’ll have to buy another one (like I did TT_T). I ended up using a cutter to cut the pins before removing the grey things.

Then go fix the triggers using the Hex Inverter mod detailed on SRK here.

Fixed Triggers

While you’re at it, assemble the Imp board too.

Don’t forget to mount the joystick and woodblocks.

Almost ready to wire!

The barrier strip there will be used to hold all the ground connections for convenience.

Next I did all the internal wiring between the 360 board, MC Cthulhu, and Imp boards.

360 Cthulhu Imp

The documentation that comes with the boards should make most of it clear, but this post on SRK also helped me out a bit, particularly for the Cthulhu-360 connections.

The idea here is to wire all the 360 inputs (and V+ and Gnd) to the matching inputs on the Cthulhu and wire the data lines (D+/D-) to the Imp.

Next, I wired up all the buttons and the joystick.

Button Wiring

Note that there are 2 signal wires coming from each button. Green goes to the Cthulhu’s screw terminals and White goes to the LED board so I can do LED activation on press. The ground wires are just daisy-chained and then connected to the ground terminal block.

I also installed the RJ45 jack so that I could have detachable cables. The tutorial for that on SRK is here.

Wiring the RJ45

Make sure V+, Gnd, D+, and D- are wired to the Imp. Everything else goes to the Cthulhu. I also found it helpful to note which pins are which on the jack for future reference.

Used the Neutrik Ethercon RJ45 connector since it looks boss and also just happens to be 28mm, matching the Start, Select buttons (no need to buy any more hole saws).

Trim the signal wires and try to get all the lengths correct and the wires neater. Then connect everything to the Cthulhu’s screw terminals.

Connecting to the Cthulhu

Sharp-eyed readers will note the adhesive cable tie-down I used in the upper right of the above pic. Those things are really nice for routing the wiring and keeping stuff cleaner. I found them in the automotive section in Wal-Mart.

If you want to, you can start testing the stick to see if the basics work.

Next is to start making the thing light up.

Instead of going the normal inverter IC route, my friend came up with a circuit for his Mayflash in order to make the lights fade in and out. I modified it a little and came up with this:

LED Circuit Design

The resistor values will depend on what LED you’re using. Choose a capacitor value accordingly. Remember that the time constant = RC. So if you use different resistors to match different colors of LEDs (like I did), change the capacitors accordingly.

To select the capacitor value, I just experimented with a few of them. Make sure to use a normal electrolytic polarized cap. Aim for about 1000uF.

I used some perfboard I got from Radioshack to make the circuit.

One LED Channel

Here’s one channel for the LED circuit. 2 resistors to handle the 2 LEDs in the button. I made 7 more of these for all 8 buttons on my stick.

The +5V red wire and Ground black wire are connected to the appropriate screw terminal on the Cthulhu. Meaning, that this LED circuit will just piggyback off of the Cthulhu’s power.

Full LED Circuit

As you can tell from this pic, adding LEDs requires a whole bunch of extra wires. One extra signal wire from the button and 2 extra wires (signal and ground) for each LED in the button, then multiply that by how many buttons you have. Solution: Lots of wires.

Cleaning everything up a little, here’s all the wires:

Completed Wiring

Test everything, close it all up, test it again.

Congrats! New arcade stick!

Completed Arcade Stick!