Arduino + WiiChuck steered laser pointer

Here’s something I made for fun a couple months ago and I need to make it again soon so I’m posting schematics and Source code for anyone to download and make their own fun toy with Arduino.

Parts list:

  • Arduino Uno
  • Original Wii Nunchuck
  • Nunchuk to Arduino adapter (link below)
  • Laser pointer
  • 2 mini Servos

You can buy an adapter here :

http://todbot.com/blog/2008/02/18/wiichuck-wii-nunchuck-adapter-available/

We are using the Wire library for I2C communication with the Nunchuk. See this reference where the I2C pins are on your Arduino: http://www.arduino.cc/en/Reference/Wire. On Arduino Uno the I2C pins are A4 and A5.

See schematics for more details on how to connect the components.

[code lang="arduino"]
#include <Wire.h>
#include <string.h>
#include <stdio.h>

uint8_t outbuf[6];

int cnt = 0;
int ledPin = 13;
int laserPin = 12;
int servoPin = 9;
int servoPin2 = 10;

int pulseWidth = 0;
int pulseWidth2 = 0;

long lastPulse = 0;
long lastPulse2 = 0;

int z_button = 0;
int c_button = 0;

int refreshTime = 20;

int minPulse = 1000;
int minPulse2 = 500;

int dtime=10;

#define pwbuffsize 10
long pwbuff[pwbuffsize];
long pwbuffpos = 0;
long pwbuff2[pwbuffsize];
long pwbuffpos2 = 0;

void setup()
{
Serial.begin (9600);
Wire.begin ();
nunchuck_init ();
pinMode(servoPin, OUTPUT);
pinMode(servoPin2, OUTPUT);
pinMode(laserPin, OUTPUT);
pulseWidth = minPulse;
pulseWidth2 = minPulse2;
Serial.print ("Finished setupn");
}

void nunchuck_init()
{
Wire.beginTransmission (0x52);
Wire.write (0x40);
Wire.write (0x00);
Wire.endTransmission ();
}

void send_zero()
{
Wire.beginTransmission (0x52);
Wire.write (0x00);
Wire.endTransmission ();
}

int t = 0;

void loop()
{
t++;
long last = millis();

if( t == 1) {

t = 0;

Wire.requestFrom (0x52, 6);

while (Wire.available ()) {
outbuf[cnt] = nunchuk_decode_byte (Wire.read ());
digitalWrite (ledPin, HIGH);
cnt++;
}

if (cnt >= 5) {

// printNunchuckData();

int z_button = 0;
int c_button = 0;

if ((outbuf[5] >> 0) & 1)
z_button = 1;
if ((outbuf[5] >> 1) & 1)
c_button = 1;

switch (c_button) {
case 1:
switch (z_button) {
case 0:
digitalWrite(laserPin, LOW);
muovi();
break;
case 1:
digitalWrite(laserPin, HIGH);

muovi();
break;
}
break;
case 0:
switch (z_button) {
case 0:

break;
case 1:
//delay(3000);
break;
}
break;
}
}

cnt = 0;
send_zero();

} // if(t==)

updateServo();

delay(dtime);
}

void updateServo() {

if (millis() - lastPulse >= refreshTime) {

digitalWrite(servoPin, HIGH);
delayMicroseconds(pulseWidth);
digitalWrite(servoPin, LOW);

digitalWrite(servoPin2, HIGH);
delayMicroseconds(pulseWidth2);
digitalWrite(servoPin2, LOW);

lastPulse = millis();
}
}

int i=0;
void printNunchuckData()
{
int joy_x_axis = outbuf[0];
int joy_y_axis = outbuf[1];
int accel_x_axis = outbuf[2]; // * 2 * 2;
int accel_y_axis = outbuf[3]; // * 2 * 2;
int accel_z_axis = outbuf[4]; // * 2 * 2;

int z_button = 0;
int c_button = 0;

if ((outbuf[5] >> 0) & 1)
z_button = 1;
if ((outbuf[5] >> 1) & 1)
c_button = 1;
if ((outbuf[5] >> 2) & 1)
accel_x_axis += 2;
if ((outbuf[5] >> 3) & 1)
accel_x_axis += 1;

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

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

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

Serial.print ("X: ");
Serial.print (joy_x_axis, DEC);
Serial.print ("t");

Serial.print ("Y: ");
Serial.print (joy_y_axis, DEC);
Serial.print ("t");

Serial.print ("AccX: ");
Serial.print (accel_x_axis, DEC);
Serial.print ("t");

Serial.print ("AccY: ");
Serial.print (accel_y_axis, DEC);
Serial.print ("t");

Serial.print ("AccZ: ");
Serial.print (accel_z_axis, DEC);
Serial.print ("t");

Serial.print (z_button, DEC);
Serial.print (" ");
Serial.print (c_button, DEC);
Serial.print ("rn");
i++;
}

char nunchuk_decode_byte (char x)
{
x = (x ^ 0x17) + 0x17;
return x;
}

void muovi (){
float tilt = (700 - outbuf[3]*2*2);
float tilt2 = outbuf[2]*2*2;

tilt = (tilt);
pulseWidth = (tilt * 5) + minPulse;

tilt2 = (tilt2-288);
pulseWidth2 = (tilt2 * 5) + minPulse2;

pwbuff[pwbuffpos] = pulseWidth;
pwbuff2[pwbuffpos2] = pulseWidth2;

if( ++pwbuffpos == pwbuffsize ) pwbuffpos = 0;
if( ++pwbuffpos2 == pwbuffsize ) pwbuffpos2 = 0;

pulseWidth=0;
pulseWidth2=0;

for( int p=0; p<pwbuffsize; p++ ){
pulseWidth += pwbuff[p];
pulseWidth2 += pwbuff2[p];
}

pulseWidth /= pwbuffsize;
pulseWidth2 /= pwbuffsize;

}

[/code]

You can download all code here :

WiiChuck Source code and schematics

Or Get it on Github (improvements welcome!):

https://github.com/msurguy/arduino-wiichuck-laser