簡介

偶然在箱子里發現一個舊的Wii Nunchuk手柄，又叫“雙節棍”手柄，我想它是否可以用來控制Arduino，查閱了相關資料，確定Nunchuk手柄支持I2C方式連接到Arduino， 通過不斷地研究深入，最后從todbot.com等網站上找到了相關的控制Will nunchuk的代碼，于是就將代碼移植過來，實現了 Will nunchuk 對伺服電機的控制！

Wii Nunchuk接口定義

把Wii Nunchuk和Arduino連接起來有幾種方法，我們可以買一個Wii nunchuk的適配器，或者像剪斷連接線，確保手柄再不需要和Wii連接使用了。本文采用了剪斷線的方法，剪線之后再焊接了插針到nunchuk的連線，這樣就可以和面包板更好的連接了。下圖是Wii Nunchuk的接口定義 。

Wii Nunchuk手柄接口定義

Wii Nunchuk連接Arduino

手柄白線 （GND） –》 Arduino GND

手柄紅線 （ +5V ） –》 Arduino 5V

手柄綠線 （SDA） –》 模擬引腳 4 或者 專用的 SDA pin

手柄黃線 （SCL） –》 模擬引腳 5 或者 專用的 SCL pin

連接伺服電機到Arduino

雙軸舵機云臺

Servo 1 （x-axis）

舵機棕線 （GND） –》 Arduino GND

舵機紅線 （5V） –》 Arduino 5V

舵機黃線 （data/Signal） –》 Arduino Pin 10

Servo 2 （y-axis）

舵機棕線 （GND） –》 Arduino GND

舵機紅線 （5V） –》 Arduino 5V

舵機黃線 （data/Signal） –》 Arduino Pin 9

舵機云臺連接Arduino UNO

連接全部組件

代碼部分

使用Arduino IDE上傳代碼前，需要兩個標準庫： Wire.h 、 Servo.h 。

代碼的執行順序如下：

初始化Nunchuk手柄的I2C接口；

初始化伺服系統 ；

讀取Nunchuk手柄的數據；

根據讀取得 Nunchuk 手柄的實時數據控制伺服電機運動。

完整代碼如下：

/*

* NunchuckPrint

* 2007 Tod E. Kurt, http://todbot.com/blog/

* Change log:

*

* Mark Tashiro - Changed Wire.read to Wire.write

* Changed Wire.receive to Wire.read

* Added code for servos

*/

#include

#include

Servo servoLeft; // Define left servo

Servo servoRight; // Define right servo

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

void setup()

{

Serial.begin(19200);

servoLeft.attach(10); // Set left servo to digital pin 10

servoRight.attach(9); // Set right servo to digital pin 9

nunchuck_setpowerpins(); // use analog pins 2&3 as fake gnd & pwr

nunchuck_init(); // send the initilization handshake

Serial.print ("Finished setup\n");

}

void loop()

{

nunchuck_get_data();

// map nunchuk data to a servo data point

int x_axis = map(nunchuck_buf[0], 23, 222, 180, 0);

int y_axis = map(nunchuck_buf[1], 32, 231, 0, 180);

//move servo to desired position based on Wii nunchuk reading

servoLeft.write(x_axis);

servoRight.write(y_axis);

// un-comment next line to print data to serial monitor

// nunchuck_print_data();

}

//

// Nunchuck functions

//

// 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

void nunchuck_init()

{

Wire.begin(); // join i2c bus as master

Wire.beginTransmission(0x52); // transmit to device 0x52

Wire.write(0x40); // sends memory address

Wire.write(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.write(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.read());

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:");

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++;

}

// 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;

}