Original credit goes to alpinedelta

here: https://www.instructables.com/id/Game-Boy-Android-Gamepad/

and here: https://www.instructables.com/id/Make-your-own-Game-Boy-Android-Gamepad-1/

I really like the idea behind using a physical game pad for the inputs of various games on my phone, however I felt that there was more potential than there was with the original game pad shown in the previous links. Whenever doing a project, I always like to ask myself how can I make it better? Things that I wanted to improve with my Game Boy was I didn't want to lose any functionality with the Wiimote itself, and I just wanted some other things here and there to make it more aesthetically pleasing. I hope that you like the improvements shown in this instructable.

Step 1: Parts Needed

Parts Needed:
Game Boy (I used a broken DMG Game Boy found on eBay)
Wiimote
DMG Game Boy game cartridge (Came with my Game Boy)
Holster for phone
Phone (I have the Galaxy SIII, but any phone that is supported by the "Wiimote Controller" app found in the Play Store will work)
BIC Round Stic Cap (cap)

I have it on good authority that if you jail break your iPhone, you will have access to pairing a Wiimote with your iPhone, but I don't have any experience with that. Here are some instructables that may be able to assist you with it, but again, I have no experience with it so follow at your own risk.

https://www.instructables.com/id/Play-Nintendo-games-on-the-idevice-with-a-Wiimote-/

https://www.instructables.com/id/Jailbroken-iPhone-emulator-controller/

Tools Needed:
Drill
Drill Bits
Hot Glue Gun
Dremel Tool
Soldering Iron (40W and 15W)
Solder
Sandpaper
Gorilla Glue
Screw Driver
Pliers
Box Cuter
Hack Saw (I didn't have my Dremel by the time I needed it so I used a hack saw, you could use a Dremel just as well)
File
Wire
Wire Strippers
De-soldering Pump/Braid
And any other tools that you feel would make any process seem easier

Step 2: Dis-assembly of Holster, Game Boy, and Wiimote

Phone Holster:
Take apart your phone holster. All that I had to do with mine was take the clip off and glue the holster pivot in place.

DMG Game Boy:
Next step is to disassemble your Game Boy. There are 6 screws holding your Game Boy together. The screw may either be regular philips heads, or you may need to get a special tri-wing screw driver for your Game Boy (you will need this later for your Wiimote as well). Once you remove all 6 screws carefully detach the ribbon cable connecting the two main boards. It will just slide out to rear main board.

Now remove all screws holding rear main board.

Take out the metal shield we will not be needing this piece.

Remove and clean the battery terminals, I let them soak in baking soda water to clean off the corrosion.

Now remove all the screws from the front board.

Save all the pieces!

Now remove the screen cover. The glue here is so old it should just pop right out.

At this point in time, we have all the electronics taken out from inside the Game Boy. I would recommend cleaning every nook and cranny to get it looking as much like new as possible. I let mine soak in hot dish water and scrubbed it as much as I could. Just remember to take the sticker off the back. I took mine off nicely with a box cutter under one of the corners. It just peeled off and I was able to put it back on once it was all clean.

Wiimote:
There are 4 tri-wing screws holding your Wiimote together. Take them out. There are still 2 clips holding the front together, be careful if you care about putting it together later, just rip it apart if you don't.

Once you have the two parts separated, everything else comes out quite easily. Make sure to keep everything. We won't need most parts, but better safe than sorry.

Step 3: Game Boy Mod - Front Half

Measure the opening that you would like for your holster. Make sure that it fits just as you'd like it. I wanted mine just a little bit lower than the face of the Game Boy. It's totally up to you. I used a hack saw for my cut across the top. (I didn't have my Dremel tool yet it would work just as well if not better) I then used a box cuter to cut the rest out because I wanted a nice straight line the rest of the way around. Make sure that you keep the piece that you are cutting out, you will need it later.

File down the edges as you see fit to give your phone bracket the desired depth inside your Game Boy. Check your fit and make sure that it's just how you'd like it.

Take the part that was cut out of the front of the Game Boy; we are going to cut out the mount for the LED. It's that round little piece, cut it out. We are going to use it to mount that LED somewhere else. Once you have it cut out, find a place on the front of your Game Boy that you would like to mount it. Before you start drilling holes in your Game Boy for the LED we need to get a lens to go over it. The best thing that I found that was clear and perfectly round was the cap from a BIC Round Stic. If you find one around your house you will know and understand what I'm talking about. Just cut that round piece out and find the correct diameter bit and drill that hole. Once you have the correct size hole, go ahead and glue the lens in there followed by the bracket for the LED.

Step 4: Game Boy Mod - Front Circuits

Take the front circuit that has been removed.

First remove the screen, we will not be needing this.

Remove the speaker and save for later, we will be soldering this to the speaker output for the Wiimote.

Take a knife and mark where you want to cut the front circuit board. Once marked take your Dremel tool and cut the circuit board. Make sure to cut above the mounting holes. We need these holes to mount the circuit back on the Game Boy.

Once you have done this we need to create a way to hold the two halves of the Game Boy together. I just made some braces out of some spare wood that I had lying around and positioned them right over the holes. When the two halves are placed together it will hold together securely.

Step 5: Game Boy Mod - Back Half

Next we need to cut apart the battery compartment to make room for the Wiimote circuitry inside of the Game boy.

There is just enough room for the Wiimote in the battery compartment if you cut to one side of the plastic pieces that divide the individual cells. That's what you see here.

Make sure not to cut off the bracket for the headphone jack. I wanted to use this to make it look as stock as possible. If you don't care about mounting your headphone jack here, feel free to cut it off.

Now look at the battery compartment, we need to change things so that the battery contacts can be put in place.

Unsolder the positive and negative battery contacts from the rear circuit of the Game Boy.

Take your Dremel tool and carefully cut a notch to allow the contacts to slide right into place. (you will see two notches cut, don't cut the one on the bottom of the battery compartment, that was a mistake!)

Once placed how you'd like, feel free to glue them in place. Use a set of AA batteries to act as the clamp to hold them in place.

Step 6: Desoldering - Wiimote and Game Boy

Wiimote:
There are a few components on the Wiimote that we will need to de-solder in order to accomplish all of the goals of this instructable. The two main pieces that we need to de-solder is the IR camera on the front of the Wiimote and the nun-chuck port on the back. I used a 40-watt iron with a lot of de-soldering braid to make sure that I got every bit of solder from in there to make sure that nothing was damaged in the soldering process. De-solder the Nun-chuck port and rumble pack as well.

Game Boy:
We have already desoldered the battery terminals from the Game Boy, we still need to desolder the LED and the headphone jack for future use.

Step 7: Wiimote Inside Game Boy

Now that you have those pieces removed from your Wiimote, you can now place the circuit inside your Game Boy. After placing it inside your Game Boy you will realize that you will need a shim to hold the Wiimote level. The one shown in these pictures was too large for the final project. The ideal size is the width of the circuit and when placed in there it will go up to where the contacts come out for the IR camera.

Now cut a notch in the post that's holding the back side of the game pad circuit tight against the front. This will as well hold the Wiimote circuit in place.

Step 8: Game Boy Mod - IR Camera

Like I said in the intro I wanted the Wiimote to have full functionality with an actual Wii, so a window is needed for the IR camera. Enlarge the opening on the front piece of the Game Boy to accept a larger window. Once the opening is square, take the original Wiimote window and cut it down to size with your Dremel tool.

As I have mentioned before I wanted as many things to be as stock and original as possible, so I wanted the game cartridge lock that is attached to the on off switch to be in place. Just cut off the switch part and glue in the lock when you glue in the window. (only glue the window in place on the back half of the Game Boy and not the front half)

Step 9: Game Boy Mod - Nun-chuck Port

To have access to the Nun-chuck connector, we need to cut the slot for the link cable port open just a bit more. Just so it slides in nicely and stays there without any glue.

Also cut off the tab from the front half of the Game Boy, it will get in the way of the Nun-chuck port.

Step 10: Soldering Game Boy Game Pad

Next solder wires along the traces that correspond to the buttons on the Game Boy. Make sure to label these wires so that you know what to solder where on the Wiimote. When soldering along these traces just scratch the insulation from the traces and you will be able to solder right from there.

Step 11: Soldering Wires on the Wiimote

Now take those wires that you soldered to the Game Boy circuit, and solder them in place on the Wiimote. Correspond the correct labelled wires with where they go to. When soldering your "select" and "start" buttons on to the "+" and "-" buttons, make sure to only solder on the bottom side of the switch. Meaning the side closer toward the nun-chuck port.

Solder wires coming from the battery terminals to the power on the Wiimote itself.

Solder wires on the LED that was de-soldered from the Game Boy earlier. Make sure to solder the anode of the LED to the positive power terminal of the Wiimote, and the cathode of the LED to the cathode of the player 1 LED on the Wiimote. I tinned the tip of the wire going to the LED on the Wiimote to help in soldering.

Cover up the 4 LED's on the Wiimote with electric tape. We don't want that light coming through any cracks later on.

Step 12: Putting It All Together

Last step is to put everything together. What I did to mount my holster to the front was I used 4 flat head wood screws right into the wood supports. That way if I ever get a different phone I can easily swap out the holster.

Hot glue the LED in the LED holder on the front face of the Game Boy.

Hot glue the game cartridge in place in the cartridge slot.

I had a great time making this and I hope that I can inspire you with other great ideas.

I am still looking for a way to mount lever switches over the "contrast" and "volume" holes to add some shoulder buttons to the controller. I plan on taking the control knobs and cutting them of to clue on the lever switches. There are still the "home" button as well as "A" and "B" still available on the Wiimote.

I will update this as soon as those changes have been made on my end.

Thank you for reading and let me know if you have any questions or attempt a build like this.