Hacking the Wii U Gamepad

[Arisotura]

Could be nifty for small homebrew, or even just improving the original functionality. I don't know, but this project scratches a very specific itch for me, and who knows what people will come up with?

Regarding wifi, it's a bit of a weird thing. Either way, you'd need a Wii U or a special wifi network to be able to flash anything onto the gamepad in the first place. But maybe supporting regular wifi networks could make things more convenient later on. I don't know, I just don't like not having the option.

[lidnariq]

Do we know how fast the main CPU in the gamepad is? In other words, how much could rely on it instead of the h.264 decoder in it?

[Arisotura]

It's an ARM9, and runs at 108MHz. Could probably be overclocked but not sure how high it can go.

The limiting factor would mostly be RAM, there's only 4MB and the framebuffer has to be in there...

[lidnariq]

With only 100MHz it's going to be hard to do much of general interest. Maybe some of the less accurate emulators?

[nocash]

100MHz is a lot, and the display is probably a lot better than Sony's 32x32 pixel Pocketstation.
Being compatible with normal access points would be certainly nice!

The initial installation with needing a Wii U or special network might be an extra obstacle.
At least when not having such things, but I guess most people who have a Wii U gamepad do also have a Wii U console, so that's propably no big issue.

And I assume that there are some options, like installing via serial cable, or perhaps installing from a NDS/DSi/3DS console, or anything that is capable of sending more or less custom wifi packets(?)

[stan423321]

Last time I checked, it was easier to get a working Wii U console without a GamePad than a working GamePad without a Wii U console. While this could be an advantage for installation purposes, it feels very much like a disadvantage for the sourcability purposes - one would imagine the GamePad owners want to keep their Wii U set fully operational, I know I do. (There is a lot of software, including the firmware, that could gracefully handle the lack of GamePad, but just doesn't.) A game tech-adjacent YouTuber MattKC has announced looking into making an open PC/Android app or add-on that would work as a practical replacement of official GamePad uses, but disregarding the chances of outright failure I think it's going to take a while, and even then the remaining GamePads would probably be important for figuring out emulation inaccuracies. In the meantime, there are a lot of new devices with significantly more power, better user programmability, and prices that many find reasonable. Sure, 100 MHz ARM9 beats PocketStation, but that's not really what people will compare it to.

This is not intended as a discouragement of looking into the low-level workings of the device, just as a note that hacking it is unlikely to ever be practical for a typical amateur hackery enthusiast, unless it interacts with the rest of Wii U.

[Arisotura]

The gamepad has an IR transceiver that can function as a serial interface, so that could be a way to load stuff to it.

Of course, you'd still need a Wii U or special network to load custom code in the first place, because the only purely software way is via the firmware update functionality. Unless there's an exploit in the firmware that could be exploited over IR or whatever.

[calima]

It's mostly pre-2000 laptops and phones that even had IR, so may be even less convenient that way.

[Pokun]

IR LEDs and receivers can easily be bought and used with an Arduino or something.

[calima]

Yes, which was my point - buying a wireless stick is easier than buying an IR setup nowadays.

[Pokun]

Wireless stick? My point was that IR hardware is easy to buy and use. There seems to be USB adapters for use with a modern computer as well but I have no idea how well they work or if they are expensive or hard to get hold of.