위 IMU 사용하고 있으며 사용한 코드는 아래와 같습니다.
#include "Wire.h"
// I2Cdev and MPU9250 must be installed as libraries, or else the .cpp/.h files
// for both classes must be in the include path of your project
#include "I2Cdev.h"
#include "MPU9250.h"
#include "BMP180.h"
// class default I2C address is 0x68
// specific I2C addresses may be passed as a parameter here
// AD0 low = 0x68 (default for InvenSense evaluation board)
// AD0 high = 0x69
MPU9250 accelgyro;
I2Cdev I2C_M;
uint8_t buffer_m[6];
int16_t ax, ay, az;
int16_t gx, gy, gz;
int16_t mx, my, mz;
float heading;
float tiltheading;
float Axyz[3];
float Gxyz[3];
float Mxyz[3];
#define sample_num_mdate 5000
volatile float mx_sample[3];
volatile float my_sample[3];
volatile float mz_sample[3];
static float mx_centre = 0;
static float my_centre = 0;
static float mz_centre = 0;
volatile int mx_max = 0;
volatile int my_max = 0;
volatile int mz_max = 0;
volatile int mx_min = 0;
volatile int my_min = 0;
volatile int mz_min = 0;
float temperature;
float pressure;
float atm;
float altitude;
BMP180 Barometer;
void setup()
{
// join I2C bus (I2Cdev library doesn't do this automatically)
Wire.begin();
// initialize serial communication
// (38400 chosen because it works as well at 8MHz as it does at 16MHz, but
// it's really up to you depending on your project)
Serial.begin(38400);
// initialize device
Serial.println("Initializing I2C devices...");
accelgyro.initialize();
Barometer.init();
// verify connection
Serial.println("Testing device connections...");
Serial.println(accelgyro.testConnection() ? "MPU9250 connection successful" : "MPU9250 connection failed");
delay(1000);
Serial.println(" ");
// Mxyz_init_calibrated ();
}
void loop()
{
getAccel_Data();
getGyro_Data();
getCompassDate_calibrated(); // compass data has been calibrated here
getHeading(); //before we use this function we should run 'getCompassDate_calibrated()' frist, so that we can get calibrated data ,then we can get correct angle .
getTiltHeading();
Serial.println("calibration parameter: ");
Serial.print(mx_centre);
Serial.print(" ");
Serial.print(my_centre);
Serial.print(" ");
Serial.println(mz_centre);
Serial.println(" ");
Serial.println("Acceleration(g) of X,Y,Z:");
Serial.print(Axyz[0]);
Serial.print(",");
Serial.print(Axyz[1]);
Serial.print(",");
Serial.println(Axyz[2]);
Serial.println("Gyro(degress/s) of X,Y,Z:");
Serial.print(Gxyz[0]);
Serial.print(",");
Serial.print(Gxyz[1]);
Serial.print(",");
Serial.println(Gxyz[2]);
Serial.println("Compass Value of X,Y,Z:");
Serial.print(Mxyz[0]);
Serial.print(",");
Serial.print(Mxyz[1]);
Serial.print(",");
Serial.println(Mxyz[2]);
Serial.println("The clockwise angle between the magnetic north and X-Axis:");
Serial.print(heading);
Serial.println(" ");
Serial.println("The clockwise angle between the magnetic north and the projection of the positive X-Axis in the horizontal plane:");
Serial.println(tiltheading);
Serial.println(" ");
temperature = Barometer.bmp180GetTemperature(Barometer.bmp180ReadUT()); //Get the temperature, bmp180ReadUT MUST be called first
pressure = Barometer.bmp180GetPressure(Barometer.bmp180ReadUP());//Get the temperature
altitude = Barometer.calcAltitude(pressure); //Uncompensated caculation - in Meters
atm = pressure / 101325;
Serial.print("Temperature: ");
Serial.print(temperature, 2); //display 2 decimal places
Serial.println("deg C");
Serial.print("Pressure: ");
Serial.print(pressure, 0); //whole number only.
Serial.println(" Pa");
Serial.print("Ralated Atmosphere: ");
Serial.println(atm, 4); //display 4 decimal places
Serial.print("Altitude: ");
Serial.print(altitude, 2); //display 2 decimal places
Serial.println(" m");
Serial.println();
delay(1000);
}
void getHeading(void)
{
heading = 180 * atan2(Mxyz[1], Mxyz[0]) / PI;
if (heading < 0) heading += 360;
}
void getTiltHeading(void)
{
float pitch = asin(-Axyz[0]);
float roll = asin(Axyz[1] / cos(pitch));
float xh = Mxyz[0] * cos(pitch) + Mxyz[2] * sin(pitch);
float yh = Mxyz[0] * sin(roll) * sin(pitch) + Mxyz[1] * cos(roll) - Mxyz[2] * sin(roll) * cos(pitch);
float zh = -Mxyz[0] * cos(roll) * sin(pitch) + Mxyz[1] * sin(roll) + Mxyz[2] * cos(roll) * cos(pitch);
tiltheading = 180 * atan2(yh, xh) / PI;
if (yh < 0) tiltheading += 360;
}
void Mxyz_init_calibrated ()
{
Serial.println(F("Before using 9DOF,we need to calibrate the compass frist,It will takes about 2 minutes."));
Serial.print(" ");
Serial.println(F("During calibratting ,you should rotate and turn the 9DOF all the time within 2 minutes."));
Serial.print(" ");
Serial.println(F("If you are ready ,please sent a command data 'ready' to start sample and calibrate."));
while (!Serial.find("ready"));
Serial.println(" ");
Serial.println("ready");
Serial.println("Sample starting......");
Serial.println("waiting ......");
get_calibration_Data ();
Serial.println(" ");
Serial.println("compass calibration parameter ");
Serial.print(mx_centre);
Serial.print(" ");
Serial.print(my_centre);
Serial.print(" ");
Serial.println(mz_centre);
Serial.println(" ");
}
void get_calibration_Data ()
{
for (int i = 0; i < sample_num_mdate; i++)
{
get_one_sample_date_mxyz();
/*
Serial.print(mx_sample[2]);
Serial.print(" ");
Serial.print(my_sample[2]); //you can see the sample data here .
Serial.print(" ");
Serial.println(mz_sample[2]);
*/
if (mx_sample[2] >= mx_sample[1])mx_sample[1] = mx_sample[2];
if (my_sample[2] >= my_sample[1])my_sample[1] = my_sample[2]; //find max value
if (mz_sample[2] >= mz_sample[1])mz_sample[1] = mz_sample[2];
if (mx_sample[2] <= mx_sample[0])mx_sample[0] = mx_sample[2];
if (my_sample[2] <= my_sample[0])my_sample[0] = my_sample[2]; //find min value
if (mz_sample[2] <= mz_sample[0])mz_sample[0] = mz_sample[2];
}
mx_max = mx_sample[1];
my_max = my_sample[1];
mz_max = mz_sample[1];
mx_min = mx_sample[0];
my_min = my_sample[0];
mz_min = mz_sample[0];
mx_centre = (mx_max + mx_min) / 2;
my_centre = (my_max + my_min) / 2;
mz_centre = (mz_max + mz_min) / 2;
}
void get_one_sample_date_mxyz()
{
getCompass_Data();
mx_sample[2] = Mxyz[0];
my_sample[2] = Mxyz[1];
mz_sample[2] = Mxyz[2];
}
void getAccel_Data(void)
{
accelgyro.getMotion9(&ax, &ay, &az, &gx, &gy, &gz, &mx, &my, &mz);
Axyz[0] = (double) ax / 16384;
Axyz[1] = (double) ay / 16384;
Axyz[2] = (double) az / 16384;
}
void getGyro_Data(void)
{
accelgyro.getMotion9(&ax, &ay, &az, &gx, &gy, &gz, &mx, &my, &mz);
Gxyz[0] = (double) gx * 250 / 32768;
Gxyz[1] = (double) gy * 250 / 32768;
Gxyz[2] = (double) gz * 250 / 32768;
}
void getCompass_Data(void)
{
I2C_M.writeByte(MPU9150_RA_MAG_ADDRESS, 0x0A, 0x01); //enable the magnetometer
delay(10);
I2C_M.readBytes(MPU9150_RA_MAG_ADDRESS, MPU9150_RA_MAG_XOUT_L, 6, buffer_m);
mx = ((int16_t)(buffer_m[1]) << 8) | buffer_m[0] ;
my = ((int16_t)(buffer_m[3]) << 8) | buffer_m[2] ;
mz = ((int16_t)(buffer_m[5]) << 8) | buffer_m[4] ;
Mxyz[0] = (double) mx * 1200 / 4096;
Mxyz[1] = (double) my * 1200 / 4096;
Mxyz[2] = (double) mz * 1200 / 4096;
}
void getCompassDate_calibrated ()
{
getCompass_Data();
Mxyz[0] = Mxyz[0] - mx_centre;
Mxyz[1] = Mxyz[1] - my_centre;
Mxyz[2] = Mxyz[2] - mz_centre;
}
