Setting up emulation of a Wii extension

Supplies

• A controller built using one of the other guides

• A microcontroller

  • The Pi Pico 1, Pi Pico 2, or microcontrollers based on them, are currently the only supported microcontrollers. Previous versions of santroller did support other microcontrollers, and information about that can be found below.

    Legacy microcontrollers

    • The following microcontrollers are only supported by v10.1.188. They are no longer supported by recent versions of Santroller, and bug fixes and features from newer versions of Santroller will not be ported to them.
      • Sparkfun Pro Micro (5v)
        • The 5V Pro Micro will work fine for direct wiring, but being that it runs at 5V, it will require voltage conversion to build Wii adapters and PS2 adapters and turntables.
      • Sparkfun Pro Micro (3.3v)
        • If you want to build an adapter for a Wii or PS2 guitar, this will be easier to use than any of the 5V microcontrollers. Due to the lower voltage, these do run at half the speed of the 5v variants, a. Clones of the Pro Micro are quite cheap but will need to be purchased from eBay or AliExpress, real Pro Micros are expensive, but there isn't much of a difference. 3.3V arduinos will poll a Wii guitar slightly slower than a 5V Arduino but in practice this doesn't end up being important as there are a lot of other delays involved when communicating with a Wii guitar.
      • Arduino Micro
        • This is essentially the same thing as a Pro Micro 5V, except that it is officially made by Arduino. This causes it to be more expensive compared to a Raspberry Pi Pico.
      • Arduino Leonardo
        • The Arduino Leonardo is essentially a 5V Pro Micro, except it has the layout of an Arduino Uno. You can find clones of these, but they are still more expensive then a Pro Micro or a Raspberry Pi Pico.
      • Arduino Uno (r1/r2/r3)
        • The Arduino R1, R2, and R3 controllers are actually two microcontrollers in one, and they work in tandem to provide a working controller. This has its disadvantages, as code needs to keep these controllers in sync, and this can result in issues if a bad configuration is programmed, and generally results in requiring more complicated and optimised code to work. Unos do still get 1000hz, but if you are buying a new microcontroller, we recommend against purchasing them. Note that some clone Arduino Unos are actually missing the second microcontroller, and these ones will NOT work at all. If you see an Arduino Uno listing that mentions "ch340g" or something similar, do not purchase it. Due to this, they are harder to purchase and since they require more parts, they are more expensive than a Pro Micro or Pi Pico.
      • Arduino Mega 2560
        • These are in the same situation as the Uno, however the main microcontroller has a lot more pins. They also end up being more expensive due to the amount of parts that are needed to make one.
    • Incompatible microcontrollers
      • Arduino Uno R4
        • This is the latest entry to the Arduino Uno line of products. The Arduino Uno R4 is unsupported due to using a different microcontroller.
      • Arduino Mini or Nano or Pro Mini or Pro Nano
        • These do NOT work, as they are essentially Unos that lack the second micro controller that allow for custom USB device emulation.
      • ESP32
        • Currently this is not supported due to the base ESP32 not fully supporting USB. There are some ESP32 models that have USB support, but these end up being more expensive than the Pi Pico, and thus it does not make sense to support these.

• A Wii extension plug
• Some Wire
• A Soldering Iron

Steps

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.

   

   Danger

   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_CC, 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 V_CC on the microcontroller to the V_CC on the plug, through the diode

   • On the Pi Pico, use V_SYS
   • On the 3.3V Pro Micro, use V_CC

3. Connect the gnd pin to the gnd on your microcontroller.

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

Programming

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.

USB Host

Make sure you follow the relevant steps outlined in the USB Host Guide as some extra wiring is necessary to power USB devices when using Wii Extension Emulation.