File content as of revision 3:2e25f16c9fc3:

#include "mbed.h"
#include "MPU9250.h"
#include "MS5611I2C.h"

float sum = 0;
uint32_t sumCount = 0;
char buffer[14];
const uint16_t dly_ms = 33;    // delay for o/p computing and printing

MPU9250 mpu9250;

//MS5611I2C ms5611(I2C_SDA, I2C_SCL, false);

Timer t;
Serial pc(USBTX, USBRX); // tx, rx

//HC-05
Serial bt(D1,D0);

/* MAIN */        
int main()
{  
  //HC-05
  bt.baud(9600);
  //prints data on mobile
  //bt.printf("Connection Established\r\n");
  //print data on pc terminal
  pc.printf("Connection Established\r\n");
  
  //pc.baud(115200);  
  //pc.baud(256000);

  //Set up I2C
  i2c.frequency(400000);  // use fast (400 kHz) I2C  
   
  //pc.printf("CPU SystemCoreClock is %d Hz\n", SystemCoreClock);   
   
  //Print the Coefficients from the 
  //ms5611.printCoefficients();
  
  t.start();        
   
  // Read the WHO_AM_I register, this is a good test of communication
  uint8_t whoami = mpu9250.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250);  // Read WHO_AM_I register for MPU-9250
  //pc.printf("I AM 0x%x\n", whoami); //pc.printf("I SHOULD BE 0x71\n");
  
  if (whoami == 0x71) // WHO_AM_I should always be 0x68
  {  
    wait(1);
    
    mpu9250.resetMPU9250(); // Reset registers to default in preparation for device calibration
    mpu9250.MPU9250SelfTest(SelfTest); // Start by performing self test and reporting values
    mpu9250.calibrateMPU9250(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers  

    wait(2);
    mpu9250.initMPU9250(); 
    //pc.printf("MPU9250 initialized for active data mode....\n"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
    mpu9250.initAK8963(magCalibration);
    //pc.printf("AK8963 initialized for active data mode....\n"); // Initialize device for active mode read of magnetometer
    //pc.printf("Accelerometer full-scale range = %f  g\n", 2.0f*(float)(1<<Ascale));
    //pc.printf("Gyroscope full-scale range = %f  deg/s\n", 250.0f*(float)(1<<Gscale));
    if(Mscale == 0) //pc.printf("Magnetometer resolution = 14  bits\n");
    if(Mscale == 1) //pc.printf("Magnetometer resolution = 16  bits\n");
    if(Mmode == 2) //pc.printf("Magnetometer ODR = 8 Hz\n");
    if(Mmode == 6) //pc.printf("Magnetometer ODR = 100 Hz\n");
    wait(1);
   }
   else
   {
        pc.printf("Could not connect to MPU9250: \n");
        pc.printf("%#x \n",  whoami);
        while(1) ; // Loop forever if communication doesn't happen
    }

    mpu9250.getAres(); // Get accelerometer sensitivity
    mpu9250.getGres(); // Get gyro sensitivity
    mpu9250.getMres(); // Get magnetometer sensitivity
    magbias[0] = +470.;  // User environmental x-axis correction in milliGauss, should be automatically calculated
    magbias[1] = +120.;  // User environmental x-axis correction in milliGauss
    magbias[2] = +125.;  // User environmental x-axis correction in milliGauss


// main loop
 while(1) {  
  // If intPin goes high, all data registers have new data
  if(mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) {  // On interrupt, check if data ready interrupt
    mpu9250.readAccelData(accelCount);  // Read the x/y/z adc values   
    // Now we'll calculate the accleration value into actual g's
    ax = (float)accelCount[0]*aRes - accelBias[0];  // get actual g value, this depends on scale being set
    ay = (float)accelCount[1]*aRes - accelBias[1];   
    az = (float)accelCount[2]*aRes - accelBias[2];  
   
    mpu9250.readGyroData(gyroCount);  // Read the x/y/z adc values
    // Calculate the gyro value into actual degrees per second
    gx = (float)gyroCount[0]*gRes - gyroBias[0];  // get actual gyro value, this depends on scale being set
    gy = (float)gyroCount[1]*gRes - gyroBias[1];  
    gz = (float)gyroCount[2]*gRes - gyroBias[2];   
  
    mpu9250.readMagData(magCount);  // Read the x/y/z adc values   
    // Calculate the magnetometer values in milliGauss
    // Include factory calibration per data sheet and user environmental corrections
    mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0];  // get actual magnetometer value, this depends on scale being set
    my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1];  
    mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2];   
  }
  
    Now = t.read_us();
    deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update
    lastUpdate = Now;
    
    sum += deltat;
    sumCount++;
    
    // Pass gyro rate as rad/s
    //mpu9250.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f,  my,  mx, mz);
    mpu9250.MahonyQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);

    delt_t = t.read_ms() - count;
    
    if (delt_t > dly_ms) {     
        yaw   = atan2(2.0f * (q[1] * q[2] + q[0] * q[3]), q[0] * q[0] + q[1] * q[1] - q[2] * q[2] - q[3] * q[3]);   
        pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2]));
        roll  = atan2(2.0f * (q[0] * q[1] + q[2] * q[3]), q[0] * q[0] - q[1] * q[1] - q[2] * q[2] + q[3] * q[3]);
        pitch *= 180.0f / PI;
        yaw   *= 180.0f / PI; 
        //yaw   -= 13.8f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04
        yaw   -= 3.8f; // Declination in Cork, Ireland in Oct 2016
        roll  *= 180.0f / PI;

        pc.printf("%.2f,%.2f,%.2f,%.2f,%.2f,%.2f\r\n", 
        yaw,
        pitch, 
        roll,
        ax,
        ay,
        az
        );
        
        // Send it to HC-06
        bt.printf("%.2f,%.2f,%.2f,%.2f,%.2f,%.2f\n", 
            yaw,
            pitch, 
            roll,
            ax,
            ay,
            az
            );            
        
        myled= !myled;
        count = t.read_ms(); 

        if(count > 1<<21) {
            t.start(); // start the timer over again if ~30 minutes has passed
            count = 0;
            deltat= 0;
            lastUpdate = t.read_us();
        }
        sum = 0;
        sumCount = 0; 
    }
} 
}