I want to have my computer listen to messages between my Nintendo GameCube and a controller. (This is just for fun, not for streaming or anything.) I've spliced into the cable as described here in order to use NintendoSpy.

However, most people do this by using arduinos and I am not willing to spend any money on this project. I am trying to use a Sparkfun Photon Redboard as the arduino with spliced extension cables and nintendospy, but it won't work, and I am 90% sure I have the correct wire colors plugged in to digital ports (for the data wire) and ground. NintendoSpy opens on COM8 (the port which the board is plugged into) but nothing pops up, even with the Gamecube on. Since the photon red board is very similar to an arduino I am not sure why it won’t work. Any help is appreciated

  • I can't quite picture your setup here. Are you just connecting your controller to your redboard, or is the redboard eavesdropping on communication between the controller and the gamecube?
    – Kaz
    Commented Jul 23, 2019 at 20:10
  • I have the controller connected to an extension cable, which is spliced. The complete wire is connected to the GameCube itself, but the data wire and the ground wire are connected to the board as well. It’s basically eavesdropping on the signal, I guess. I followed this guide for an arduino: docs.google.com/document/d/…
    – Komali
    Commented Jul 23, 2019 at 20:23
  • also the nintendospy Firmware can't be downloaded onto the board as the arduino will not recognize the board
    – Komali
    Commented Jul 23, 2019 at 23:14
  • I've edited your question to clarify exactly to what on the GameCube you're trying to connect and include the your link to the instructions you were using. At any time you should feel free to edit questions further to clarify or add things you've forgotten; this helps people first seeing the question understand it more quickly.
    – cjs
    Commented Jul 24, 2019 at 2:48
  • Also, adding links (as I did for NintendoSpy and you should do for the RedBoard) greatly increases your chances of getting help, since it means that people wanting to help you don't all have to start out by doing web searches for the things you're talking about.
    – cjs
    Commented Jul 24, 2019 at 2:57

1 Answer 1


There are actually two software programs involved here: NintendoSpy running on your computer and a program that must run on the Arduino. The program running on the Arduino reads data from the spliced game controller cable and communicates with NintendoSpy on the PC to tell it what it saw.

I'm guessing that NintendoSpy has contained in it a version of this program compiled for an ATMega328 CPU, uploads it to the Arduino device when it's first connected to it via the COM port, and then starts it. After that NintendoSpy would talk with the running program as above.

Unfortunately, your RedBoard, though the same physical shape as an Arduino, is otherwise vastly different. The voltage levels are different, which means that you probably shouldn't connect it to the Nintendo controller cable without using a voltage converter (or you may damage your board), it has a completely different CPU (ARM Cortex M3 instead of ATMega328) and it doesn't even appear to use the standard Arduino protocols for uploading software to it.

Basically, your board is a certain physical shape so that it can use a few Arduino peripherals, but otherwise it seems not to be an Arduino. It's like a computer with IBM PC-shaped slots that is otherwise completely different from an IBM PC.

If you wanted to use this board you would probably need to:

  1. Modify the Arduino part of NintendoSpy code (under the firmware/ directory) to run on your board. Since your board doesn't appear to be supported by the Arduino IDE, this could be a very large project.
  2. Build a new version of NintendoSpy that would upload your modified code to your board; since the communications protocols seem to be different this could also be a huge project. Alternatively, modify NintendoSpy so that it doesn't do the upload but instead assumes the board software is already running, and do the upload and start the software yourself before asking NintendoSpy to connect.

If you want to pursue this route, the Arduino StackExchange is probably a good place to post questions related to this. But given its difficulty, it seems worthwhile to spend the $10-15 just to buy an Arduino Uno clone to run this. You may also be able to use a cheaper Micro or Nano ($5-10, or even less), though if those are not directly supported by NintendoSpy you may have to tweak the firmware program just slightly.

Even if you do switch to an Arduino, the Adruino StackExchange is still probably better than here to post about difficulties connecting NintendoSpy to the Arduino itself, since they will know more about Arduino/PC connectivity. Once you've got NintendoSpy talking to the Arduino and have the cable pins plugged into the right sockets, questions about the actual game controller protocol would be appropriate here.


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