Question

我正在开展一个项目，将Nintendo Nunchuk与Arduino同步。我在http://letsmakerobots.com/node/5684

找到了相同的在线代码

这里是代码

#include <Wire.h>;

void setup(){
Serial.begin(19200);
nunchuck_setpowerpins();
nunchuck_init();
Serial.print("Nunchuck ready\n");
}

void loop(){
nunchuck_get_data();
nunchuck_print_data();
delay(1000);
}
//======================================================================================================================================================================================================//
//Do not modify!!!!!!!!
//======================================================================================================================================================================================================//


//
// Nunchuck functions
//

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
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()"
void nunchuck_send_request()
{
Wire.beginTransmission(0x52);   // transmit to device 0x52
Wire.send(0x00);     // sends one byte
Wire.endTransmission(); // stop transmitting
}

// Receive data back from the nunchuck,
// returns 1 on successful read. returns 0 on failure
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
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;
}

// returns zbutton state: 1=pressed, 0=notpressed
int nunchuck_zbutton()
{
return ((nunchuck_buf[5] >> 0) & 1) ? 0 : 1; // voodoo
}

// returns zbutton state: 1=pressed, 0=notpressed
int nunchuck_cbutton()
{
return ((nunchuck_buf[5] >> 1) & 1) ? 0 : 1; // voodoo
}

// returns value of x-axis joystick
int nunchuck_joyx()
{
return nunchuck_buf[0];
}

// returns value of y-axis joystick
int nunchuck_joyy()
{
return nunchuck_buf[1];
}

// returns value of x-axis accelerometer
int nunchuck_accelx()
{
return nunchuck_buf[2]; // FIXME: this leaves out 2-bits of the data
}

// returns value of y-axis accelerometer
int nunchuck_accely()
{
return nunchuck_buf[3]; // FIXME: this leaves out 2-bits of the data
}

// returns value of z-axis accelerometer
int nunchuck_accelz()
{
return nunchuck_buf[4]; // FIXME: this leaves out 2-bits of the data
}

当我写下Serial.Println（“End”）时，在Wire.endTransmission（）之后的行中;在函数nunchuck_init（）中，它不会显示在串行监视器上。

此外，它不会在串行监视器上显示Nunchuck准备就绪，因为它是在调用nunchuck_init（）之后编写的。我正在开发Arduino 0023，Windows 7。

Answer 1

库存Arduino Wire库存在的问题是没有超时 endTransmission功能可以在不同的情况下挂起微控制器。

此问题已在其他几个forums中讨论过，我到目前为止找到的最佳解决方案是使用备用库。

Wayne Truchsess的Arduino I2C主库
http://www.dsscircuits.com/index.php/articles/66-arduino-i2c-master-library

通过适当的超时，它解决了我的系统上读取MMA7455加速器的问题

在提供的源代码中，有一个示例，它显示了如何使用Wire与I2C主库完成相同的程序。您可以使用该示例轻松修改代码以采用新库。

Arduino代码在Wire.endTransmission行之后没有执行

1 个答案: