Setting up an Adapter for a Wii Controller

This guide walks through the hardware and software setup required to use a Wii controller extension with Santroller.

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Supplies

Required

• Microcontroller

  • Raspberry Pi Pico users: this legacy release does not support Pico boards. Use the currently supported Santroller tooling at santroller.com.

• SparkFun Pro Micro (5V or 3.3V)

  • The 3.3V version is easier to use with Wii and PS2 controllers. The 5V version requires voltage conversion for 3.3V peripherals.

• Arduino Micro

• Arduino Leonardo

• Arduino Uno R1, R2, or R3

  • The board must have the ATmega16U2 USB controller. Uno clones that use a CH340 USB chip are not supported.

• Arduino Mega 1280, Mega 2560, or Mega ADK

• Wii Extension breakout board or extension cable

  • Example: Adafruit Wii Nunchuck Breakout Adapter
  • You may also cut the end off an extension cable and solder directly if preferred

• Wire

• Soldering iron

Power considerations

• If your Wii Extension breakout does not support 3.3V input and you are using a 5V microcontroller, you will need a 3.3V voltage regulator
• The Adafruit breakout linked above supports both 3.3V and 5V input and does not require an external regulator

Optional features

Tilt support

Any of the following options are supported:

• Digital tilt switch (sometimes called a mercury or ball tilt switch)

  • Using two tilt switches in series is recommended to reduce accidental activations

• Digital accelerometers: ADXL345 or LIS3DH

  • Provides analog acceleration data
  • Tilt is detected using acceleration due to gravity
  • While the MPU-6050 is supported, it has been obselete for years now, and thus most MPU-6050s that can be purchased are fakes and the fake units have many issues, so it is recommended to stay away from them.

• Analog accelerometers: ADXL335 or accelerometers found in some Guitar Hero guitars

  • Provides analog acceleration data
  • Tilt is detected using acceleration due to gravity

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Finished product

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Wiring steps

1. Connect SDA and SCL

Connect the SDA and SCL pins from your Wii Extension breakout or extension cable to your microcontroller.

Refer to the image below for the Wii Extension connector pinout.

Microcontroller	SDA	SCL
Pro Micro / Leonardo / Micro	2	3
Uno	A4	A5
Mega	20	21

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2. Connect power (VCC)

• Connect the microcontroller VCC to the breakout VCC
• If using a 5V Pro Micro and a breakout that does not support 5V input, route VCC through a 3.3V regulator
• On the Arduino Uno, use the onboard 3.3V pin
• On the Adafruit breakout:
  • VIN accepts both 3.3V and 5V input
  • The 3V pin is an output and is not required

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3. Connect ground

Connect GND on the Wii Extension breakout or cable to GND on the microcontroller.

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4. Optional: tilt wiring

Digital tilt

1. Connect one pin of the first tilt switch to ground
2. Connect the other pin of the first switch to one pin of the second switch
3. Connect the remaining pin of the second switch to a digital input on the microcontroller
4. Mount the switches on the guitar and adjust placement to control activation angle

Analog tilt

1. Connect GND to GND
2. Connect VCC to VCC
3. Connect the signal pin to an analog input

ADXL345 / MPU-6050 / LIS3DH

1. Connect GND to GND
2. Connect VCC to 3.3V (use a regulator if required)
3. Connect SDA and SCL using the table above

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Programming

1. Launch Santroller with the microcontroller connected
2. Set Connection Method to Wii Adapter
3. Set Device to Emulate to the desired controller type
4. Click Configure
5. Click Save Settings

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Windows controller mode

This setting only affects Windows behavior. Consoles and other operating systems automatically select the correct mode.

• XInput

  • Native Windows support
  • Most games auto-bind controls

• HID

  • No automatic binding
  • Slightly more efficient polling in games like Clone Hero

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Polling and debounce

• Controller Poll Settings allows adjustment of polling behavior
• Queue Based Inputs queues inputs internally and sends them at the USB maximum rate (1 ms)

Poll rate settings:

• 0 sends data as fast as possible
• Any other value polls at the specified rate
• DJ Hero turntables must use a poll rate of 10

Debounce:

• Filters noisy button signals
• Prevents dropped sustains caused by button bounce

Combined strum debounce (guitars only):

• Shares debounce timing between strum up and strum down
• Prevents rebound-triggered extra strums

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Wii Extension inputs

1. Open Wii Extension Inputs
2. Click Save

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Calibration

Use the Wii Inputs to display below dropdown if multiple devices are connected.

Joysticks / crossfader

1. Click Calibrate and move fully left or up
2. Click Next and move fully right or down
3. Click Next and move slightly off center to set the deadzone

Whammy bar

1. Click Calibrate
2. Release the whammy and click Next
3. Fully press the whammy and click Next
4. Release again and click Next

Turntable spin

• Adjust the multiplier if responsiveness is too low

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Configuring tilt in Santroller

Ensure you are emulating a guitar, then click Add Setting and add Tilt.

Digital tilt

1. Set Input Type to Digital Pin Input
2. Set Pin Mode to Pull Up
3. Click Find Pin and tilt the guitar
4. Enable Invert if using an inverted-output sensor such as some SW520D variants

Analog tilt

1. Set Input Type to Analog Pin Input
2. Click Find Pin and tilt the guitar
3. Click Calibrate
4. Tilt down and click Next
5. Tilt up and click Next
6. Hold the resting position and click Next

Accelerometer-based tilt

1. Click Add Setting and add Accelerometer
2. Click Save
3. Set Input Type to Accelerometer Input
4. Click Calibrate
5. Hold the resting position and click Next
6. Tilt up and click Next
7. Tilt slightly upward and click Next to set the deadzone
8. Adjust the Low Pass Filter
   • Values near 0 reduce shake sensitivity but lower responsiveness
   • Values near 1 increase responsiveness but amplify noise
   • A starting value of 0.05 is recommended