I'm a bit of a newbie to all this, however I've successfully got this hack to work and am now keen on sending out the nunchuck's sensor data via midi. Tod Kurt did some great work with his recent 'Bionic Arduino' class and so I contacted him and he graciously replied. The probelm is that I may not have made it clear enough how much of a beginner I am. Anyway, I've begun modifying his version of the above code but I was wondering if anyone else has tried to send MIDI data from the nunchuck? and if so would they like to help me achieve results?

/* Nunchuck to MIDI
*
* Based upon:
* NunchuckServo 2007 Tod E. Kurt, http://todbot.com/blog/
*
* The Wii Nunchuck reading code is taken from Windmeadow Labs
* http://www.windmeadow.com/node/42
*/

#include

#define middleC 60
#define LEDpin 13

//Variables
int ledPin = 13;

void setup()
{
Serial.begin(31250); //baud rate for MIDI

nunchuck_init(); // send the initilization handshake
Serial.print ("Finished setup\n");
}

void loop()
{

//THIS IS WHERE I NEED TO 'CAPTURE' THE NUNCHUCK VALUES

nunchuck_get_data();
nunchuck_print_data();
delay(100);
}

//
// Nunchuck functions
//

static uint8_t nunchuck_buf[6]; // array to store nunchuck data,

// initialize the I2C system, join the I2C bus,
// and tell the nunchuck we're talking to it
void nunchuck_init()
{
Wire.begin(); // join i2c bus as master
Wire.beginTransmission(0x52); // transmit to device 0x52
Wire.send(0x40); // sends memory address
Wire.send(0x00); // sends sent a zero.
Wire.endTransmission(); // stop transmitting
}

// Send a request for data to the nunchuck
// was "send_zero()"
void nunchuck_send_request()
{
Wire.beginTransmission(0x52); // transmit to device 0x52
Wire.send(0x00); // sends one byte
Wire.endTransmission(); // stop transmitting
}

// Receive data back from the nunchuck,
int nunchuck_get_data()
{
int cnt=0;
Wire.requestFrom (0x52, 6); // request data from nunchuck
while (Wire.available ()) {
// receive byte as an integer
nunchuck_buf[cnt] = nunchuk_decode_byte(Wire.receive());
cnt++;
}
nunchuck_send_request(); // send request for next data payload
// If we recieved the 6 bytes, then go print them
if (cnt >= 5) {
return 1; // success
}
return 0; //failure
}

// Print the input data we have recieved
// accel data is 10 bits long
// so we read 8 bits, then we have to add
// on the last 2 bits. That is why I
// multiply them by 2 * 2
void nunchuck_print_data()
{
static int i=0;
int joy_x_axis = nunchuck_buf[0];
int joy_y_axis = nunchuck_buf[1];
int accel_x_axis = nunchuck_buf[2]; // * 2 * 2;
int accel_y_axis = nunchuck_buf[3]; // * 2 * 2;
int accel_z_axis = nunchuck_buf[4]; // * 2 * 2;

int z_button = 0;
int c_button = 0;

// byte nunchuck_buf[5] contains bits for z and c buttons
// it also contains the least significant bits for the accelerometer data
// so we have to check each bit of byte outbuf[5]
if ((nunchuck_buf[5] >> 0) & 1)
z_button = 1;
if ((nunchuck_buf[5] >> 1) & 1)
c_button = 1;

if ((nunchuck_buf[5] >> 2) & 1)
accel_x_axis += 2;
if ((nunchuck_buf[5] >> 3) & 1)
accel_x_axis += 1;

if ((nunchuck_buf[5] >> 4) & 1)
accel_y_axis += 2;
if ((nunchuck_buf[5] >> 5) & 1)
accel_y_axis += 1;

if ((nunchuck_buf[5] >> 6) & 1)
accel_z_axis += 2;
if ((nunchuck_buf[5] >> 7) & 1)
accel_z_axis += 1;

Serial.print(i,DEC);
Serial.print("\t");

Serial.print("joy:"); //tag
Serial.print(joy_x_axis,DEC); //x axis value
Serial.print(","); //next value
Serial.print(joy_y_axis, DEC); //y axis value
Serial.print(" \t");

Serial.print("acc:");
Serial.print(accel_x_axis, DEC);
Serial.print(",");
Serial.print(accel_y_axis, DEC);
Serial.print(",");
Serial.print(accel_z_axis, DEC);
Serial.print("\t");

Serial.print("but:");
Serial.print(z_button, DEC);
Serial.print(",");
Serial.print(c_button, DEC);

Serial.print("\r\n"); // newline
i++;
}

// Encode data to format that most wiimote drivers except
// only needed if you use one of the regular wiimote drivers
char nunchuk_decode_byte (char x)
{
x = (x ^ 0x17) + 0x17;
return x;
}

// returns zbutton state: 1=pressed, 0=notpressed
int nunchuck_zbutton()
{
return ((nunchuck_buf[5] >> 0) & 1) ? 0 : 1; // voodoo
}

// returns zbutton state: 1=pressed, 0=notpressed
int nunchuck_cbutton()
{
return ((nunchuck_buf[5] >> 1) & 1) ? 0 : 1; // voodoo
}

// returns value of x-axis joystick
int nunchuck_joyx()
{
return nunchuck_buf[0];
}

// returns value of y-axis joystick
int nunchuck_joyy()
{
return nunchuck_buf[1];
}

// returns value of x-axis accelerometer
int nunchuck_accelx()
{
return nunchuck_buf[2]; // FIXME: this leaves out 2-bits of the data
}

// returns value of y-axis accelerometer
int nunchuck_accely()
{
return nunchuck_buf[3]; // FIXME: this leaves out 2-bits of the data
}

// returns value of z-axis accelerometer
int nunchuck_accelz()
{
return nunchuck_buf[4]; // FIXME: this leaves out 2-bits of the data
}