Arduino Uno Quick Start Manual page 166

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class Nunchuk {
5
public:
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void initialize();
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bool update();
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int joystick_x()
10
int joystick_y()
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int x_acceleration()
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return ((int)(_buffer[2]) << 2) | ((_buffer[5] >> 2) & 0x03);
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}
15
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int y_acceleration()
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return ((int)(_buffer[3]) << 2) | ((_buffer[5] >> 4) & 0x03);
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}
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20
int z_acceleration()
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return ((int)(_buffer[4]) << 2) | ((_buffer[5] >> 6) & 0x03);
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}
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bool z_button() const
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bool c_button() const
25
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private:
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void request_data();
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char decode_byte(const
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30
unsigned char _buffer[NUNCHUK_BUFFER_SIZE];
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};
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#endif
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This small C++ class is all you need to use a Nunchuk controller with your
Arduino. It starts with a double-include prevention mechanism: it checks
whether a preprocessor macro named
using #ifndef . If it hasn t been defined, we define it and continue with the
declaration of the Nunchuk
ration, so you can safely include this header file more than once in your
application.
In line 3, we create a constant for the size of the array we need to store the
data the Nunchuk returns. We define this array in line 31, and in this case,
we define the constant using the preprocessor instead of the
because array constants must be known at compile time in C++.
Then the actual declaration of the
nication channel between the Arduino and the Nunchuk, you have to invoke
const { return _buffer[0]; }
const { return _buffer[1]; }
const {
const {
const {
{ return !(_buffer[5] & 0x01); }
{ return !(_buffer[5] & 0x02); }
char);
__NUNCHUK_H__
class. Otherwise, the preprocessor skips the decla-
Nunchuk
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Building a Nunchuk Class
has been defined already
const
class begins. To initiate the commu-
149
keyword,
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