It's easy to use the Wii Nunchuck Breakout Adapter with CircuitPython and the Adafruit CircuitPython Nunchuk module.  This module allows you to easily write Python code that reads controls from the Wii Nunchuck.

You can use this sensor with any CircuitPython microcontroller board or with a computer that has GPIO and Python thanks to Adafruit_Blinka, our CircuitPython-for-Python compatibility library.

CircuitPython Microcontroller Wiring

First wire up a Wii Nunchuck Adapter Breakout to your board exactly as follows. Here is an example of the Nunchuck Adapter wired to a Feather using I2C:

  • Board 3V to sensor VIN (red wire)
  • Board GND to sensor GND (black wire)
  • Board SCL to sensor SCL (yellow wire)
  • Board SDA to sensor SDA (blue wire)

Python Computer Wiring

Since there's dozens of Linux computers/boards you can use we will show wiring for Raspberry Pi. For other platforms, please visit the guide for CircuitPython on Linux to see whether your platform is supported

Here's the Raspberry Pi wired with I2C:

  • Pi 3V3 to sensor VIN (red wire)
  • Pi GND to sensor GND (black wire)
  • Pi SCL to sensor SCL (yellow wire)
  • Pi SDA to sensor SDA (blue wire)

CircuitPython Installation of Nunchuck Library

You'll need to install the Adafruit CircuitPython Nunchuk library on your CircuitPython board.

First make sure you are running the latest version of Adafruit CircuitPython for your board.

Next you'll need to install the necessary libraries to use the hardware--carefully follow the steps to find and install these libraries from Adafruit's CircuitPython library bundle.  Our CircuitPython starter guide has a great page on how to install the library bundle.

Copy the following files from the bundle to the lib folder on your CIRCUITPY drive:

  • adafruit_nunchuk.mpy
  • adafruit_bus_device

Before continuing make sure your board's lib folder or root filesystem has the adafruit_nunchuk.mpy, and adafruit_bus_device file and folder copied over.

Next connect to the board's serial REPL so you are at the CircuitPython >>> prompt.

Python Installation of Nunchuck Library

You'll need to install the Adafruit_Blinka library that provides the CircuitPython support in Python. This may also require enabling I2C on your platform and verifying you are running Python 3. Since each platform is a little different, and Linux changes often, please visit the CircuitPython on Linux guide to get your computer ready!

Once that's done, from your command line run the following command:

  • pip3 install adafruit-circuitpython-nunchuk

If your default Python is version 3 you may need to run 'pip' instead. Just make sure you aren't trying to use CircuitPython on Python 2.x, it isn't supported!

CircuitPython & Python Usage

To demonstrate the usage of the sensor we'll initialize it and read from the controller in the board's Python REPL.

Run the following code to import the necessary modules and initialize the I2C connection with the adapter:

import time
import board
import adafruit_nunchuk

nc = adafruit_nunchuk.Nunchuk(board.I2C())

Now you're ready to read values from the controller using these properties:

  • joystick - An (x, y) tuple of the joystick position.
  • button_C - The pressed state of button C.
  • button_Z - The pressed state of button Z.
  • acceleration - An (x, y, z) tuple of acceleration data.

For example, to read the joystick position:

x, y = nc.joystick
print("joystick = {},{}".format(x, y))

To read button presses on the+ buttons:

print(nc.button_C)
print(nc.button_Z)

To read the acceleration data:

ax, ay, az = nc.acceleration
print("accceleration ax={}, ay={}, az={}".format(ax, ay, az))

That's all there is to using the Adafruit Wii Nunchuk Breakout Adapter with Python and CircuitPython!

Full Example Code

This example reads all the data in a loop.

# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

import time
import board
import adafruit_nunchuk

i2c = board.I2C()  # uses board.SCL and board.SDA
# i2c = board.STEMMA_I2C()  # For using the built-in STEMMA QT connector on a microcontroller
nc = adafruit_nunchuk.Nunchuk(i2c)

while True:
    x, y = nc.joystick
    ax, ay, az = nc.acceleration
    print("joystick = {},{}".format(x, y))
    print("accceleration ax={}, ay={}, az={}".format(ax, ay, az))

    if nc.buttons.C:
        print("button C")
    if nc.buttons.Z:
        print("button Z")
    time.sleep(0.5)

Nunchuck Accelerometer and Tap Detection

This section and code come from notes by CGrover used to develop tap detection for potential use in the PowerWash Simulator Controller project.

The accelerometer is very securely mounted, so the tap detection scheme only monitors the more sensitive x-axis (horizontal).

Nunchuck tap detection works best if the side of the controller handle is tapped.

Double-Tap Detection Code

# Set the Nunchuck tap detector parameters and initialize tap event history list
TAP_THRESHOLD = 350  # Tap sensitivity threshold; depends on the physical sensor mount
TAP_DEBOUNCE = 0.2  # Time for accelerometer to settle after tap (seconds)
TAP_TIMEOUT = 1500  # Remove tap event from history timeout (milliseconds)
tap_events = []  # Initialize the tap event history list

# The project's main while looop
while True:
    # Detect a tap on the x-axis of the Nunchuck accelerometer
    accel_sample_1 = nunchuck.acceleration  # Read one sample
    accel_sample_2 = nunchuck.acceleration  # Read the next sample
    if abs(accel_sample_1 - accel_sample_2) >= TAP_THRESHOLD:
        # The difference between two consecutive samples exceeded the threshold
        # (equivalent to a high-pass filter)
        print(f"SINGLE tap detected {ticks_ms()}")
        tap_events.append(ticks_ms() + TAP_TIMEOUT)  # save tap expiration time in event stack
        time.sleep(TAP_DEBOUNCE)  # Debounce delay

    # Clean up tap event history after timeout period expires
    if len(tap_events) > 0:
        # Check for expired events
        if tap_events[0] <= ticks_ms():
            # The oldest event has expired
            tap_events = tap_events[1:]  # Remove the oldest event

    # Check see if two taps are in the event history list
    if len(tap_events) == 2:
        # Double-tap: execute the task and clear event history
        print(f"DOUBLE tap detected {ticks_ms()}")
        # 
        # Perform the double-tap task here
        # 
        tap_events = []  # Clear event history

This guide was first published on Jan 10, 2021. It was last updated on Jun 24, 2024.

This page (Python & CircuitPython) was last updated on Jun 24, 2024.

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