Hi everyone! I'm trying to create a library from Krodal's code for MPU-6050 IMU. By using a library it would be a lot easier to code. Another reason for using a library is to create a function for zeroing sensor values, which needs to be in the void setup () part. The following variables (data stream from IMU) are required:
accel_t_gyro.value.n_accel
accel_t_gyro.value.n_gyro
where n=x,y,z
and a function for changing register data: MPU6050_write().
I tried to create it myself ( http://arduino.cc/en/Hacking/LibraryTutorial ), however I don't know how to go about a class structure inside the code and it's variables. Also not sure how to turn void setup() /loop () part of the code into *.cpp. I would be very grateful if you could help me with that. This library would be very beneficial for beginners, as MPU6050 is a common IMU in the market.
Below is my poor attempt to create a library with shortened version of the code. Please comment on what should I add in the header, *.cpp and keywords.txt files. Big thank you!
THE HEADER FILE (mpu6050.h):
#ifndef mpu6050_h
#define mpu6050_h
#include <Wire.h>
#define MPU6050_AUX_VDDIO 0x01 // R/W
#define MPU6050_SMPLRT_DIV 0x19 // R/W
.
all the defines as in the code: Arduino Playground - MPU-6050
.
#define MPU6050_LP_WAKE_10HZ MPU6050_LP_WAKE_CTRL_3
#define MPU6050_I2C_ADDRESS 0x68
class mpu6050
{
public:
int MPU6050_read(int start, uint8_t *buffer, int size);
int MPU6050_write(int start, const uint8_t *pData, int size);
int MPU6050_write_reg(int reg, uint8_t data);
private:
????????????
}
#endif
THE CPP FILE:
#include mpu6050.h
typedef union accel_t_gyro_union
{
struct
{
uint8_t x_accel_h;
uint8_t x_accel_l;
uint8_t y_accel_h;
uint8_t y_accel_l;
uint8_t z_accel_h;
uint8_t z_accel_l;
uint8_t t_h;
uint8_t t_l;
uint8_t x_gyro_h;
uint8_t x_gyro_l;
uint8_t y_gyro_h;
uint8_t y_gyro_l;
uint8_t z_gyro_h;
uint8_t z_gyro_l;
} reg;
struct
{
int x_accel;
int y_accel;
int z_accel;
int temperature;
int x_gyro;
int y_gyro;
int z_gyro;
} value;
};
void setup()
{
int error;
uint8_t c;
Serial.begin(9600);
Serial.println(F("InvenSense MPU-6050"));
Serial.println(F("June 2012"));
// Initialize the 'Wire' class for the I2C-bus.
Wire.begin();
error = MPU6050_read (MPU6050_WHO_AM_I, &c, 1);
Serial.print(F("WHO_AM_I : "));
Serial.print(c,HEX);
Serial.print(F(", error = "));
Serial.println(error,DEC);
error = MPU6050_read (MPU6050_PWR_MGMT_2, &c, 1);
Serial.print(F("PWR_MGMT_2 : "));
Serial.print(c,HEX);
Serial.print(F(", error = "));
Serial.println(error,DEC);
MPU6050_write_reg (MPU6050_PWR_MGMT_1, 0);
}
void loop()
{
int error;
double dT;
accel_t_gyro_union accel_t_gyro;
Serial.println(F(""));
Serial.println(F("MPU-6050"));
error = MPU6050_read (MPU6050_ACCEL_XOUT_H, (uint8_t *) &accel_t_gyro, sizeof(accel_t_gyro));
Serial.print(F("Read accel, temp and gyro, error = "));
Serial.println(error,DEC);
uint8_t swap;
#define SWAP(x,y) swap = x; x = y; y = swap
SWAP (accel_t_gyro.reg.x_accel_h, accel_t_gyro.reg.x_accel_l);
SWAP (accel_t_gyro.reg.y_accel_h, accel_t_gyro.reg.y_accel_l);
SWAP (accel_t_gyro.reg.z_accel_h, accel_t_gyro.reg.z_accel_l);
SWAP (accel_t_gyro.reg.t_h, accel_t_gyro.reg.t_l);
SWAP (accel_t_gyro.reg.x_gyro_h, accel_t_gyro.reg.x_gyro_l);
SWAP (accel_t_gyro.reg.y_gyro_h, accel_t_gyro.reg.y_gyro_l);
SWAP (accel_t_gyro.reg.z_gyro_h, accel_t_gyro.reg.z_gyro_l);
}
int mpu6050::MPU6050_read(int start, uint8_t *buffer, int size)
{
int i, n, error;
Wire.beginTransmission(MPU6050_I2C_ADDRESS);
n = Wire.write(start);
if (n != 1)
return (-10);
n = Wire.endTransmission(false); // hold the I2C-bus
if (n != 0)
return (n);
Wire.requestFrom(MPU6050_I2C_ADDRESS, size, true);
i = 0;
while(Wire.available() && i<size)
{
buffer[i++]=Wire.read();
}
if ( i != size)
return (-11);
return (0); // return : no error
}
int mpu6050::MPU6050_write(int start, const uint8_t *pData, int size)
{
int n, error;
Wire.beginTransmission(MPU6050_I2C_ADDRESS);
n = Wire.write(start); // write the start address
if (n != 1)
return (-20);
n = Wire.write(pData, size); // write data bytes
if (n != size)
return (-21);
error = Wire.endTransmission(true); // release the I2C-bus
if (error != 0)
return (error);
return (0); // return : no error
}
int mpu6050::MPU6050_write_reg(int reg, uint8_t data)
{
int error;
error = MPU6050_write(reg, &data, 1);
return (error);
}
KEYWORDS.TXT
????