Setting up emulation of a Wii extension


  • A controller built using one of the other guides

  • A microcontroller

    • The Pi Pico is recommended, but other 3.3v microcontrollers like the 3.3v pro micro may work. 5v only microcontrollers will NOT work.
  • A Wii extension plug

  • Some Wire

  • A Soldering Iron


NEVER plug in both the usb cable to your computer, and the extension to a wii remote, it can only ever be plugged into one device at a time!


  1. Connect wires between the SDA and SCL pins on your wii extension plug. Refer to the following image for the pinout of a Wii Extension plug.

    The Pi Pico lets you pick from various pins for the SDA and SCL pins. We provide recommended pins below, and this pinout is the same as the old Ardwiino firmware. If you need to use other pins, the options are provided below but the SDA and SCL pins must be from the same channel.



    Do NOT rely on the colours, the manufacturers are all over the place with this and the only way to validate them is to test each wire according to the above image. I’ve come across connectors wired with green as ground and black as 3.3V before, you just can’t rely on the colours at all unfortunately. Even cables from guitar hero guitars don’t use expected colours, I found that on mine, device detect was shorted to V<sub>CC</sub>, and then white was ground!

    Microcontroller SDA SCL
    Pi Pico (Recommended) GP18 GP19
    Pro Micro, Leonardo, Micro 2 3
    Pi Pico (Advanced, Channel 0) GP0, GP4, GP8, GP12, GP16, GP20 GP1, GP5, GP9, GP13, GP17, GP21
    Pi Pico (Advanced, Channel 1) GP2, GP6, GP10, GP14, GP18, GP26 GP3, GP7, GP11, GP15, GP19, GP27
  2. Connect the VCC on the microcontroller to the VCC on the plug

    • On the Pi Pico, use VSYS
    • On the 3.3V Pro Micro, use VCC
  3. Connect the gnd pin to the gnd on your microcontroller.

  4. If your plug doesn't already connect device detect to VCC inside the cable, connect device detect to VCC.


  1. Start Santroller with your microcontroller plugged in.
  2. Hit Configure
  3. Click on Add Setting
  4. Find Wii Extension Emulation in the dropdown and add it
  5. For the Pi Pico, set your SDA and SCL pins.