Tuesday, September 9, 2008

Mod Diary: NintendAxe Part 1

Having completed a handful of mods in the Harmonix Stratocaster and Red Octane Les Paul guitar controllers I have decided that it is time to tackle the big kahuna: the guitar controller built into an NES Console.

There is the rough idea of the body of the guitar. It is something that I am still working on in my head. But till the time comes to start cutting into 23 year old Japanese plastic lets look at something a little less major. The directional controls for the guitar will come not only from the up and down action of the strum bar, but also from a functional directional pad like one would find on the face of a Les Paul, Strat, or Xplorer. Unlike the strummer assembly that I will basically be cutting out of a Les Paul and gluing into the face of the NES case I have opted to create the control interface from something not on an already produced guitar contoller:

Here is the NES Controller... inside out. D-Pad on the left, buttons of the right, start and select in the middle, the NES controller is the grandpappy of modern gaming interface. Every controller you have sitting in your entertainment center is more or less and more ergonomic version of this controller with more buttons. The plan is to wire the guitar controls of the Les Paul into face controls of the NES controller with the directional pad correlating to the guitar D-Pad, start and select to start and back and A and B functioning as the Xbox A and B buttons or green and red keys on the guitar respectively.

The first step of this mod is to hard wire the fret buttons of the LP into the logic board of the guitar. In the LP there are 8 wires that run from the fret board and to hard wire I just lined up the wires, snipped off the bits of silicon used for the detachable neck feature, and soldered the connections directly together with a bit of speaker wire.

To figure out how to set the A and B button on the Nintendo controller I needed to figure out which wires resulted in which kind of button press. For future notice here is how the wiring on the LP fretboard works.

(Like I said before, there are eight wires running from the body of the guitar into the neck.)

Closing the circuit between wires 1 and 8 results in a green button press, closing 2 and 7 produces a red. These are the two most important to the project. Connect wires 2 and 6 and you get a yellow fret press, and if 2 and 5 are closed it is a blue press. To activate the orange button connect wires 4 and 5.

So the next step was first to cut the cable from the NES controller itself (yay wireless!). Then I very carefully scrapped the coat of whatever it is off of the top of the printed copper leads running into the A and B buttons. The next step was the drill a very small hole near where I scrapped so as to stick a wire through and then solder it down to the board itself.

After that it is as simple as soldering the wires into the corresponding fret wires. The next portion on the other hand was not particularly difficult but definitely more nerve racking. In the LP the main logic board of the controller, the brains more or less, are on one circuit with all kinds of transistors and such on one side and the contacts for the directional pad and Xbox button on the other. In order to reconfigure the Les Paul directional pad it is required that you solder directly on the logic board, something I was nervous about primarily because if you cook the logic board it is time for a new guitar. Luckily the contacts themselves are straight copper contacts and as long as you give them enough heat with the soldering iron they accept the solder well.

This is the point of no return basically. This thing isn't going back inside the LP, and now we gotta wire up the directional buttons on the NES controller with the extra wires off of the now octopus-esque LP logic board. Like before it is a matter of uncovering copper, drilling holes and soldering down the wires. However, unlike the A and B button, the directional buttons of the NES controller have individual leads for one pole of each button and share a lead for the other one. As such some of the copper needs to be removed to prevent weird shorting between the buttons.

And there ya go. One NES controller wired into the Xbox LP controls.

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