Today, in part 2, we'll reattach some vital components, mount the disc drive back onto the motherboard and create a case design on the computer. This will prepare everything for part 3, where we'll make the casing and install everything into it. Move out!
Alright, when we last left our hero (the Wii?), the unit was stripped down to the motherboard and the heat sink had been modified. Granted the original heat sink wasn't that tall, but the plan was to keep the main body of the unit under 1.25 inches. Setting goals like that (instead of just shotgunning it and coming up with a case that looks like the Winchester Mystery House) is what allows a person to create a professional "manufactured-looking" project.
Today we're going to rework several things on the motherboard so the unit can once again function, starting with the front panel buttons.
Rewiring the front panel buttons
The Wii has 4 buttons on the front of the unit: power, reset, sync and eject disc. These buttons use a very common thing called a tact switch. These are used for the panel switches on just about every piece of electronics you can find -- from laserdisc players to VCRs and even televisions. Even the Gameboy Advance / DS uses them for the shoulder buttons.
The tact switches on the Wii are surface mount and thus kind of hard to remove, so we're just going to wire around them. These particular tact switches have three leads. By testing with a multimeter and pressing the button we can tell that when pressed the switch connects both outer terminals to the center one. We also find that the outer terminals are connected to each other. Thus we only need two wires per switch, one connected to the center terminal and the other to an outer terminal.
- Put a small bit of new solder on the switch lead. This melts what's already there and gets it ready for a new attachment.
- Strip a bit of plastic off the end of the wire (we always use our teeth, don't tell anyone) and coat it with a bit of solder.
- Touch the wire to the switch and heat it up. Since they're both "pre-soldered" it'll melt and connect them easily. Doing it quickly is good because even with a low power iron you can still mess up surface mount parts if you linger.
Extending the audio / video connections
Next let's add some extension wires to the audio / video port. We'll also get the sensor bar voltage from this spot. We need a total of 6 things from this spot: left audio, right audio, composite video, A/V ground, sensor bar positive and sensor bar negative.
Almost everything under the sun has had its pinouts mapped by someone or another... a quick search for "Wii av pinouts" reveals just that. Here's the link we used.
It's also helpful to label the opposite ends of the wires for later use. We often wrap a bit of Scotch tape around them and write down the signal type with a felt-tip marker.
The WiFi module has 2 wires coming off of it to form the antenna. They're of decent length, but it's a good idea to attach a plug so we can detach them with ease during our work and also extend the wires while we're at it. The module does indeed have little plugs on it already, but these are hard to work with and are also under the module when it's attached to the motherboard so they're not easy to get to.
- Carefully strip some plastic off the ends of the WiFi wires (that phrase is amazingly oxymoronic). You'll notice inside there's an outer shell of wire (ground) and an inner wire encased in plastic (signal).
- Put a bit of solder on the inner wire, then twist the outer wire strands together and put some solder on the end to keep them together.
- Connect these wires to a small plug. We used an old computer connector (the black seen thing above) Keep track of how you've wired it. We put the black signal on the side, gray signal on the outside, and the grounds in the middle.
- Use minimal amounts of solder so as to not affect the functions of the antenna. (Again, it's not rocket science, we've extended the Xbox 360 WiFi antenna in the same manner.)
- Wrap small bits of electric tape around the wire joints to keep them from shorting out to each other or the motherboard.
- Plug the WiFi module back onto the board and use a bit of glue to attach the plug to the board as well.
- Cut a piece of thin aluminum (1/16-inch works fine) to place over the module. Make it as large as possible. As seen above, a notch has been cut in the upper corner to keep an opening for the DVD drive cables.
- You can also cannibalize metal from the RF shielding to make this.
- Cover the top side of the aluminum with electric tape, to keep it from shorting out against the DVD drive's circuit board.
Next let's reinstall the battery connector that we desoldered from the back of the board in part 1.
- Reference note: the edges and top of the battery are positive, the bottom is negative (ground).
- Find a good blank spot on the board. We put our battery just behind the USB ports, near the heatsink. We used this side of the board because the opposite side at this spot will have the GameCube controller port.
- If you're going to rewire the GameCube memory ports (which seems to be a very high priority on people's minds) be sure to do it before putting down the battery. Or you can just solder the memory card connections to the bottom side of the board. This is actually easier because there's less white silkscreen mask on the bottom.
- You can solder the negative tab of the battery holder directly to the copper edge of the motherboard since it's ground anyway. This is quite handy for any type of connection (on any electronic device) and can save you the trouble of running extra ground wires.
- For the positive connection, connect a long wire between the battery holder and the original battery spot on the bottom of the motherboard.
- Place a small piece of plastic over the battery and use electrical tape to make a "hinge" on one side, on the positive terminal edge is best.
- On the opposite side glue down a chunk of soft material, such as wood or very dense foam. We can then screw the plastic hinge to this and thus hold down the battery, as shown above.
- Covering the battery with electrical tape or hot glue would also work, but might not be very convenient should you ever need to replace it. We can be a bit trigger-happy with hot glue, but in this case even we had to step back and say, "No, there's a better way."
While we're in the area let's take a look at the USB connection. We'll attach wires to it in part 3.
- Find the ground pin by seeing which is connected to the main ground of the motherboard. Ground is almost always the outermost edge of any motherboard, the part the shielding is connected to. If for some odd reason it isn't (like on the Commodore 64) then any metal shield will lead you to ground.
- The pin opposite this is +5 volts.
- The next pin over from +5 is always data -.
- Which leaves data + as the final pin.
Mounting the disc drive
The main thing we need to do as part of this rebuild is to mount the disc drive to the motherboard. Originally it attached with a variety of plastic pieces but we're going to do something much simpler.
Ok, let's move onto the frame, as shown above. (FYI, the yellow circle indicates the bit of plastic we just ground down.)
- Find a thin piece of plastic (0.063 inch thick works well) and cut it into a 5.5 x 5.5iinch square. It should be as large as the disc drive, including the mounting tabs out the back.
- Cut an opening in the plastic to fit around the circuit board on the bottom of the disc drive. By fitting the frame around the circuit board (rather than under it) we can make the unit a little thinner. Or you can just put the frame under everything, it'll still be fine. (Just not as thin.)
- Cut a large notch at the end of the frame (bottom of photo) so it can fit around the heat sink.
- Drill four holes in the frame to match the four mounting holes in the disk drive. These are the ones with the rubber "shock spacers" that we looked at in part 1. Two of them are in the tabs at the back of the drive.
- Use size 4 screws and nuts to mount the disc drive to the frame. Note the the front mounting holes are under where the disc will sit, thus you must use shorter screws so they don't get in the way.
Now we need a way to attach the frame to the motherboard. There's quite a few spare screw holes around the edges of the motherboard so we can thread screws through these for the mounting. But we'll need something in the frame for them to grab onto - the thin plastic of the frame alone isn't quite enough.
Attaching a GameCube controller port
Let's stick a GameCube port back on shall we? This can we can have better controls for some of the Virtual Console games.
The LCD screen module
We get most of our LCD modules from a place called AEI Components. The sales rep had always told us they had 7 inch widescreen LCD's for a very nice price (only about $40 more than a 3.5" screen which to us is a bargain) but until now we didn't really have a use for one. However since the Wii has a widescreen mode and that size screen would fit nicely we finally broke down and ordered one. This is about the same size as the screen on a portable DVD player.
Monument Valley not included
We believe most of the smaller LCD's from AEI (ever notice about 50% of all sentences these days consist of acronyms?) are intended for use in a car as they all come with cigarette lighter adapters and run off 12 volts. Many of them can run off much less voltage, in fact, the LED backlit 3.5 inch modules can be powered by as little as 3 volts. This particular 7 inch screen uses the more common cold cathode tube which means it contains an inverter that powers the light with a rather high stepped up voltage. Since the Wii has a 12 volt supply we can just use it directly and not have to worry if the screen will run with a lower voltage.
Unfortunately the screen only had composite video in, but at 7 inches you don't notice a huge difference anyway - many of the composite video "features" such as NTSC dot crawl aren't even noticeable. We'll talk about how to wire up the screen in part 3.
Modifying the sensor bar
First of all the "sensor bar" itself doesn't sense Jack or, um... crap (and Jack just left town). As you probably know, it's really just a bunch of infrared LED's, 5 on each side, that the Wii-mote sees as kind of a "landing strip" to tell itself where it is in relation to the TV. These infrared LED's are the same kind used on TV remotes and thus we can't see them with our eyes. They are visible, however, if you look at them through a digital camera.
Normally you can get to within a foot or two of the sensor bar before the pointer stops working. This is because at a close distance the LED lights go outside the field of view of the Wii-mote's sensor. Again, think of it like a pair of landing lights (if for some reason the entire runway wasn't lit up, a la Die Hard 2). You'd see the lights on approach, but as you get closer they end up of either side of you, thus you can't see them anymore. Same deal with the Wiimote, just no Bruce Willis.
With that hair-brained theory out it's time to test to see if we can get the Wii-mote to work a closer range.
- Take apart the sensor bar. Like the Wii, it uses the tri-wing screws. Move one of the LED circuit boards closer to the other. The normal spacing is about 7.5 inches, try it at about 4.5.
- Put the sensor bar on a "target sized item" for reference, in this case we used the LCD screen we bought for the Wii.
- Fire up the Wii and see how well it works. With mine we had the sensor working at a range of 1 foot from screen to Wiimote. Plenty close enough to see all the action, no matter what some people might have thought.
Note: You can also improve the vertical accuracy of the cursor by placing the sensor bars on both sides of a screen. About a third of the way down from the top (with the unit set to "Sensor Bar Above Screen") will make the cursor line up very closely to the vertical position of the Wii-mote. We thought about doing this for the Wii laptop but it would have made the screen portion too wide. But for people hacking their Sensor Bars or making custom ones, it might be worth playing around with.
New cord for the power supply
Originally we tried to run the Wii off a battery pack that we knew to work with the GameCube. It didn't work (with the Wii) so it can truly be said that it does in fact "have more power" -- or at least take more-- than a GameCube. Not having loads of time to find a battery pack, and considering the possible cost involved, we opted to simply integrate the power supply of the Wii into the main unit of the laptop. Again I'm sure a sufficient 12 volt battery, perhaps even from a laptop, would run it, but we didn't have the time to experiment. Feel free to discover this on your own and "pwn me".
One of the main things we did notice about the Wii is that it has a lot of pieces. Power supply, sensor bar, wii-mote, nunchuck, A/V cables... So to consolidate those parts into a few as possible would be the best route to go when making a portable. A friend of mine actually suggested we have a power cord tuck inside the unit and we realized that was a great idea. We spent at least 3 minutes thinking about it and then realized the easiest way would be to use an electric razor cord, since they are usually coiled like a phone cord (remember, back when they had cords?) and can thus stretch if need be and also fold up fairly small.
Designing a Case
With the unit rebuilt and compacted the next step is to come up with a design for the new case. Since we know the sizes of the unit, power supply and screen, we can start doing some concept sketches with the general shapes in mind. This is always a good way to go about it because a person can spend hours screwing around in a computer program or they can hash out 80% of the details on paper in a few minutes and then just translate that into pixels later on.
As usual we've used Adobe Illustrator to create our drawing. At the end of the article are links to these in a variety of formats so you can download them to study at your leisure and use as you please. We'll discuss the main views of the design below. (You can download the designs at the very bottom, too.)
Some of you have noticed that most of our stuff has a similar look, i.e. straight edges and not a lot of curves. It's not that we couldn't do curves but rather it takes longer to have them routed, plus it's slower so it adds up to more machine time / money. If we ever got around to building our own CNC machine we could do much more complex stuff but again, time is against me. One "feature" of this is that our stuff always has a look that says, "Oh yeah, Ben did that."
I created the vector-art "Wii" logo manually by drawing over a low-res bitmap of one we found on the internet. Back when we used to work for "the man" as a graphic artist we were endlessly bombarded with people wanting crappy little logos from business cards blown up to billboard sizes. Our theory is that they'd all seen to many movies when they "zoom in and clean up" some pixels in the edge of a photo and can suddenly count somebody's nose hairs, and thus believe people in real life can magically do the same thing as long as they have a computer.
On the back of the screen lid is another small compartment. This has been added because the LCD module has a small circuit board on the back of it. The main part of the LCD, the glass, is less than half and inch thick and thus we can make the main lid this thin as well. To make room for the small but required circuit board, we add a smaller empty portion on top of the lid. This is very much like the back of LCD monitors and televisions, where the main cabinet is fairly thin but there's a bulge in the back where the electronics are. As with an LCD monitor, it's best to make as much of the case as thin as possible and only have it thick where it absolutely has to be.
This drawing also shows the lid and the volume control slider that will be put on it. We'll talk more about the slider in part 3 but it's basically like those found on a mixing board. Also we see a copy of the lid objects placed in "open" format, with the center of the hinge kept in place. This allows us to gauge the angle needed on the rear portion of the unit and to get an idea of how everything is fitting together.
We have now rebuilt the Wii into a smaller form and attached many wires so we attach other parts later on. The case has also been designed and is ready to be cut with CNC machinery. In part 3 of this series, the exciting conclusion to the most detailed "how-to" we've ever put on the web (excepting, perhaps, our guide to building your own projector), we'll cut the case and assemble it, install the Wii components, wire up the screen and put in a stereo audio amplifier.
Remember, these basic techniques can be applied to all sorts of things you may want to hack or modify, not just the Wii. Gaining knowledge of how things work, along with not being intimidated by them, is a good first step on the road to hacking. Until next time...
Download Wii laptop main layout [AI, DWG, DXF, EMF, PDF]