Read Nunchuck and Wii Motion Plus (WM+) data OR 6 DOF IMU
Combination of Nunchuck accelerometers and Wii Motion Plus (WM+) gyroscopes providesfor some inexpensive and interesting 6 DOF possibilities. By using WM+ pass through port it's possible to read both Nunchuck and WM+ data. Interface this with Arduino, and it's very easyto acquire data ( or use some other board that supports I2C bus ).Since Nintendo released controllers, people figured out a way to talk to multiple devices by adding additional board, and although it's an ingenious solution ( I really do like it), it's not necessary if WM+ pass through port is utilized. For either solution wii data port adapter is needed, unless you want to cut wires on your controller. It's a non-standard connector, but it's easy to make your own DIY Wii adapter , or you could buy one from FunGizmos. Set up is:- Hook up Nunchuck into Wii Motion Plus pass-through port
- plug one end of adapter cable into other WM+ port
- the other end of cable into Arduino's I2C port pins ( Pin 4 Data and Pin 5 clock) and power and ground
- load below code
Code will provide following information:- WMP: gyro yaw, roll, and pitch data as well as velocity scaling for same axis
- Nunchuck: joystick x and y data, accelerometer x,y, and z data, and statuses of C and Z buttons
//Code for Arduino based communication with Wii Motion Plus and Nunchuck.
//Nunchuck is plugged into WM+ extension port so it DOES NOT require
//additional expansion board.
//Code, discussion, links, and references at:
//http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1248889032/0
//influenced this code, primarily contributions by
//Knuckles904, Ed Simmons, Adrian Carter, and duckhead
//Additionally, information at
//http://wiibrew.org/wiki/Wiimote/Extension_Controllers#Wii_Motion_Plus
//was very helpful.
//This code provides bases and/or example for more specific implementations
// Created by automatik (auto11)
// http://voidbot.net
//code and set up instructions at:
//http://voidbot.net/nunchchuk-and-wii-motion-plus-6-DOF.html
#include
#include
#include
//Nunchuck
uint8_t outbuf[6]; //nunchuck buffer for data
int cnt = 0; //nunchuck buffer counter
//Wii Motion Plus
byte data[6]; //buffer for WM+ data
int yaw, pitch, roll; //three gyroscope axes
int yaw0, pitch0, roll0; //calibration zeroes
bool yaw_v, pitch_v, roll_v; //calibration zeroes
void setup ()
{
beginSerial (115200);
Wire.begin (); // join i2c bus as a master
delay(100);
//instead of averaging data , I used data
//based on experiments from my particular WM+
yaw0=8163;
pitch0=7859;
roll0=8536;
}
void loop ()
{
// Data communciation is sensative hence
// bunch of timed delays. These are just
// what works on my setup so YMMV. If you
// think data is incorect increase vakues
// for delays.
wmpActive(); // activate WM+
delay(50);
extPort(); //write 0x00 to 0x(4)A400fb
delay(180);
send_zero();
DataFlush();
delay(30);
send_zero();
wmpRead(); // read WM+ data ( gyro )
wmpDeact(); // deactivate WMP
delay(50);
send_zero();
delay(70);
nunchuckRead(); // read Nunchuck data ( accelerometer data and buttons )
Serial.println("===============================================");
}
//common
//Request data
void send_zero ()
{
Wire.beginTransmission (0x52);
Wire.send (0x00); // send zero
Wire.endTransmission ();
}
void DataFlush()
{
int h=1;
Wire.requestFrom(0x52,100);
while (Wire.available())
{
Wire.receive();
h++;
}
}
//ext port
//write 0x00 to 0x(4)A400fb
void extPort()
{
Wire.beginTransmission(0x52);
Wire.send(0xfb);
Wire.send(0x00);
Wire.endTransmission();
}
//Nunchuck
void nunchuckRead()
{
Wire.requestFrom (0x52, 6); // request data from nunchuck
while (Wire.available ())
{
outbuf[cnt] = Wire.receive (); // receive nunchuck data
cnt++;
}
send_zero (); // send the request for next bytes
// If we recieved the 6 bytes, then print them
if (cnt >= 5)
{
nunchuckAssembData();
}
cnt = 0; //(NunChuck)
}
// Assemble and 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 nunchuckAssembData()
{
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;
// byte outbuf[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 ((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;
}
//Print Nunchuck Data
Serial.print (joy_x_axis, DEC);
Serial.print ("\t");
Serial.print (joy_y_axis, DEC);
Serial.print ("\t");
Serial.print (accel_x_axis, DEC);
Serial.print ("\t");
Serial.print (accel_y_axis, DEC);
Serial.print ("\t");
Serial.print (accel_z_axis, DEC);
Serial.print ("\t");
Serial.print (z_button, DEC);
Serial.print ("\t");
Serial.print (c_button, DEC);
Serial.print ("\t");
Serial.print ("\r\n");
}
//Wii Motion Plus
//Activate Wii Motion Plus
void wmpActive(){
Wire.beginTransmission(0x53);
Wire.send(0xfe);
Wire.send(0x04);
Wire.endTransmission();
}
//Deactivate Wii Motion Plus
void wmpDeact(){
Wire.beginTransmission(0x52);
Wire.send(0xf0);
Wire.send(0x55);
Wire.endTransmission();
}
void wmpRead()
{
Wire.requestFrom(0x52,6); //request data from WM+
for (int i=0;i<6;i++)
{
data[i]=Wire.receive();
}
wmpAssembData (); //assemble WM+ data
}
//assemble Wii Motion Plus data bits
//and get difference from averge values
void wmpAssembData ()
{
yaw=((data[3]>>2)<<8)+data[0];//-yaw0;
roll=((data[4]>>2)<<8)+data[1];//-roll0;
pitch=((data[5]>>2)<<8)+data[2];//-pitch0;
// get difference from avg values
// comment this out if you want to
// get raw data values
//yaw -= yaw0;
//roll -= roll0;
//pitch -= pitch0;
//scaling mode data
yaw_v = data[3] & 2;
roll_v = data[4] & 2;
pitch_v = data[3] & 1;
// print WM+ data
wmpPrintData ();
}
// print Wii Motion Plus data
void wmpPrintData ()
{
Serial.print("yaw:");
Serial.print(yaw);
Serial.print("\t");
Serial.print("pitch:");
Serial.print(pitch);
Serial.print("\t");
Serial.print("roll:");
Serial.println(roll);
Serial.print("yaw_v:");
Serial.print(yaw_v);
Serial.print("\t");
Serial.print("pitch_v:");
Serial.print(pitch_v);
Serial.print("\t");
Serial.print("roll_v:");
Serial.println(roll_v);
}