The code:
#include <Wire.h>
#include "nunchuck_funcs.h"
int loop_cnt=0;
byte accx,accy,accz,joyx,joyy,zbut,cbut;
int ledPin = 13;
int Lledpin = 2; // left led
int Rledpin = 3; // right led
int Uledpin = 4; // up led
int Dledpin = 5; // down led
void setup()
{
Serial.begin(19200);
nunchuck_setpowerpins();
nunchuck_init(); // send the initilization handshake
Serial.print("WiiChuckDemo ready\n");
}
void loop()
{
if( loop_cnt > 10 ) { // every 100 msecs get new data
loop_cnt = 0;
nunchuck_get_data();
accx = nunchuck_accelx();
accy = nunchuck_accely();
accz = nunchuck_accelz();
joyx = nunchuck_joyx();
joyy = nunchuck_joyy();
zbut = nunchuck_zbutton();
cbut = nunchuck_cbutton();
digitalRead(zbut);
if(zbut == 1 ){
digitalWrite(ledPin, HIGH);
} else {
digitalWrite(ledPin, LOW);
}
//Left led accelerometer
if(accx <= 90){
digitalWrite(Lledpin, HIGH);
} else {
digitalWrite(Lledpin, LOW);}
//Right led accelerometer
if(accx >= 180){
digitalWrite(Rledpin, HIGH);
} else {
digitalWrite(Rledpin, LOW);}
//Up led accelerometer
if(accy >= 165){
digitalWrite(Uledpin, HIGH);
} else {
digitalWrite(Uledpin, LOW);}
//Down led accelerometer
if(accy <= 100){
digitalWrite(Dledpin, HIGH);
} else {
digitalWrite(Dledpin, LOW);}
//Right led joystick
if(cbut == 1){
if(joyx >= 210){
digitalWrite(Rledpin, HIGH);
} else {
digitalWrite(Rledpin, LOW);}
//Left led joystick
if(joyx <= 50){
digitalWrite(Lledpin, HIGH);
} else {
digitalWrite(Lledpin, LOW);}
//Down led joystick
if(joyy <= 70){
digitalWrite(Dledpin, HIGH);
} else {
digitalWrite(Dledpin, LOW);}
//Up led joystick
if(joyy >= 210){
digitalWrite(Uledpin, HIGH);
} else {
digitalWrite(Uledpin, LOW);}
}
Serial.print("accx: "); Serial.print((byte)accx,DEC);
Serial.print("\taccy: "); Serial.print((byte)accy,DEC);
Serial.print("\taccz: "); Serial.print((byte)accz,DEC);
Serial.print("\tjoyx: "); Serial.print((byte)joyx,DEC);
Serial.print("\tjoyy: "); Serial.print((byte)joyy,DEC);
}
loop_cnt++;
delay(1);
}
and the nunchuck_funcs.h code
/*
* Nunchuck functions -- Talk to a Wii Nunchuck
*
* This library is from the Bionic Arduino course :
* http://todbot.com/blog/bionicarduino/
*
* 2007 Tod E. Kurt, http://todbot.com/blog/
*
* The Wii Nunchuck reading code originally from Windmeadow Labs
* http://www.windmeadow.com/node/42
*/
#include <WProgram.h>
static uint8_t nunchuck_buf[6]; // array to store nunchuck data,
// Uses port C (analog in) pins as power & ground for Nunchuck
static void nunchuck_setpowerpins()
{
#define pwrpin PORTC3
#define gndpin PORTC2
DDRC |= _BV(pwrpin) | _BV(gndpin);
PORTC &=~ _BV(gndpin);
PORTC |= _BV(pwrpin);
delay(100); // wait for things to stabilize
}
// initialize the I2C system, join the I2C bus,
// and tell the nunchuck we're talking to it
static 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()"
static void nunchuck_send_request()
{
Wire.beginTransmission(0x52);// transmit to device 0x52
Wire.send(0x00);// sends one byte
Wire.endTransmission();// stop transmitting
}
// Encode data to format that most wiimote drivers except
// only needed if you use one of the regular wiimote drivers
static char nunchuk_decode_byte (char x)
{
x = (x ^ 0x17) + 0x17;
return x;
}
// Receive data back from the nunchuck,
// returns 1 on successful read. returns 0 on failure
static 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
static 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:");
Serial.print(joy_x_axis,DEC);
Serial.print(",");
Serial.print(joy_y_axis, DEC);
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++;
}
// returns zbutton state: 1=pressed, 0=notpressed
static int nunchuck_zbutton()
{
return ((nunchuck_buf[5] >> 0) & 1) ? 0 : 1; // voodoo
}
// returns zbutton state: 1=pressed, 0=notpressed
static int nunchuck_cbutton()
{
return ((nunchuck_buf[5] >> 1) & 1) ? 0 : 1; // voodoo
}
// returns value of x-axis joystick
static int nunchuck_joyx()
{
return nunchuck_buf[0];
}
// returns value of y-axis joystick
static int nunchuck_joyy()
{
return nunchuck_buf[1];
}
// returns value of x-axis accelerometer
static int nunchuck_accelx()
{
return nunchuck_buf[2]; // FIXME: this leaves out 2-bits of the data
}
// returns value of y-axis accelerometer
static int nunchuck_accely()
{
return nunchuck_buf[3]; // FIXME: this leaves out 2-bits of the data
}
// returns value of z-axis accelerometer
static int nunchuck_accelz()
{
return nunchuck_buf[4]; // FIXME: this leaves out 2-bits of the data
}
