Has the Game Boy Advance Really Become a Switch Controller?

Robert Dale Smith has shown off a working mod that turns a Game Boy Advance into a Nintendo Switch controller, letting the 20-plus-year-old handheld properly input commands and play games on Switch. Using an old GBA Link Cable, a microcontroller, and a custom adapter, Smith demonstrated the setup by playing a GBA game on Switch with an original GBA. According to Smith, the system already works through his open-source Joypad OS firmware, with hardware costs of only a few dollars.

What makes this more than a novelty is that the GBA is not being used as a prop. Smith explained that, from the Switch side, the device appears as a standard USB controller, while a Pico adapter handles two-way communication with the GBA. The handheld’s Link Cable can also side-load a small ROM program into the system’s memory, then send and receive instructions through the cable so the GBA’s button inputs are passed along to the Switch. In practice, the Switch just sees a normal controller; the actual inputs come from the old GBA.

Smith’s demo makes the idea land immediately: he uses an original GBA to play GBA emulated software on Switch. It is a neat bit of recursion, but the real appeal is less about efficiency or replacing the Joy-Con outright and more about giving old hardware a new role. The project is interesting because it shows that a device’s lifespan is not only about age, but whether someone is still willing to build a fresh use for it.

The more important detail, though, may be how accessible Smith says the whole thing is. He has publicly stated that the open-source firmware is already finished, the hardware cost is only a few dollars, and game-side compatibility only needs a small patch. The firmware used here is his own open-source Joypad OS. If that work is eventually documented more fully, this could become more than a one-off hacker showcase and turn into a repeatable retro-controller solution.

And the idea apparently does not stop at Switch. In theory, Smith’s setup could also make the GBA compatible with PC, PlayStation 3, Xbox 360, and other platforms. The practical recommendation is straightforward: if you just want a convenient controller, this probably is not the easiest option. But if you already have a GBA in good condition and enjoy tinkering with old hardware, its appeal is obvious. Some mods are not about convenience at all; they are about finding a way to keep an old machine in your hands and useful again.

Smith has also said that if Nintendo wants to contact him, his DMs are open, adding that the idea is easy to implement. The underlying method is that once the adapter is powered by the Switch, it identifies itself to the system in USB controller mode, while the GBA handles the real button input. That same approach is why the broader multi-platform potential feels plausible rather than hypothetical.