Wii Classic Controller RP2040

Use a Wii Classic Controller with the Raspberry Pi Pico and RP2040 microcontrollers.
Implemented in C and MicroPython.

C

Include the ClassicController header and source in a project.

Call ClassicController_init() to initialize and decrypt the controller for use.

Example Code:

#include "ClassicController.h"

int main() {
    i2c_inst_t *i2c = i2c1;
    ClassicController controller;

    stdio_init_all();

    controller = ClassicController_init(i2c, 6, 7, 100000);

    while (true) {
        ClassicController_update(controller);
    }
}

C Command Reference

Command	Description
ClassicController ClassicController_init(i2c_inst_t *i2c, uint sda, uint scl, uint baudrate)	Initialize I2C connection, then Decrypt and Calibrate the controller
void ClassicController_update(ClassicController controller)	Update the Button Values
void ClassicController_calibrate(ClassicController controller)	Calibrate the Joysticks and Analog Triggers
void ClassicController_button_report(ClassicController controller)	Print a readable Input Report to the Console
int ClassicController.LX	Get value for Left Joystick x-axis $\in[-128,127]$
int ClassicController.LY	Get value for Left Joystick y-axis $\in[-128,127]$
int ClassicController.RX	Get value for Right Joystick x-axis $\in[-128,127]$
int ClassicController.RY	Get value for Right Joystick y-axis $\in[-128,127]$
int ClassicController.LT_ANALOG	Get value for Left Analog Trigger $\in[0,255]$
int ClassicController.RT_ANALOG	Get value for Right Analog Trigger $\in[0,255]$
bool ClassicController.A	Get value for Face Button A
bool ClassicController.B	Get value for Face Button B
bool ClassicController.X	Get value for Face Button X
bool ClassicController.Y	Get value for Face Button Y
bool ClassicController.UP	Get value for Directional Button UP
bool ClassicController.DOWN	Get value for Directional Button DOWN
bool ClassicController.LEFT	Get value for Directional Button LEFT
bool ClassicController.RIGHT	Get value for Directional Button RIGHT
bool ClassicController.ZL	Get value for Shoulder Button ZL
bool ClassicController.ZR	Get value for Shoulder Button ZR
bool ClassicController.LT	Get value for Shoulder Button L
bool ClassicController.RT	Get value for Shoulder Button R
bool ClassicController.START	Get value for START Button
bool ClassicController.SELECT	Get value for SELECT Button
bool ClassicController.HOME	Get value for HOME Button

MicroPython

Add ClassicController.py to the project folder.

Import the ClassicController class and create an instance. Initialization and decryption are performed automatically.

Example Code:

from ClassicController import ClassicController

controller = ClassicController(id=1, sda=6, scl=7, freq=100000)
    while (True):
        controller.update()

MicroPython Command Reference

Command	Description
update()	Update the Button Values
calibrate()	Calibrate the Joysticks and Analog Triggers
int joy_LX()	Get value for Left Joystick x-axis $\in[-128,127]$
int joy_LY()	Get value for Left Joystick y-axis $\in[-128,127]$
int joy_RX()	Get value for Right Joystick x-axis $\in[-128,127]$
int joy_RY()	Get value for Right Joystick y-axis $\in[-128,127]$
int trigger_L()	Get value for Left Analog Trigger $\in[0,255]$
int trigger_R()	Get value for Right Analog Trigger $\in[0,255]$
int button_A()	Get value for Face Button A
int button_B()	Get value for Face Button B
int button_X()	Get value for Face Button X
int button_Y()	Get value for Face Button Y
int button_UP()	Get value for Directional Button UP
int button_DOWN()	Get value for Directional Button DOWN
int button_LEFT()	Get value for Directional Button LEFT
int button_RIGHT()	Get value for Directional Button RIGHT
int button_ZL()	Get value for Shoulder Button ZL
int button_ZR()	Get value for Shoulder Button ZR
int button_LT()	Get value for Shoulder Button L
int button_RT()	Get value for Shoulder Button R
int button_START()	Get value for START Button
int button_SELECT()	Get value for SELECT Button
int button_HOME()	Get value for HOME Button

Hardware Notes

When connecting the Controller to the Pico, the SDA and SCL pins require pullup resistors to $3.3V$. I used $4.7k\Omega$ resistors for each line.

Sample Circuit

References

Relies on Wiibrew for specifics on the Classic Controller I2C interface.

Credits to This Digikey Article and PicoNunchuck by MichaelBell for code inspiration.