File content as of revision 0:ec36896926be:

#include "mbed.h"
#include "MPU9250.h"
#include "SDFileSystem.h"
#include "GPSINT.h"
DigitalOut myled(LED1);
MPU9250 mpu9250(p28,p27);               // IMU
GPSINT gps(p13,p14);                    // GPS
Serial pc(USBTX, USBRX);                // tx, rx
SDFileSystem sd(p5, p6, p7, p8, "sd");  // defines sd system
Timer t;
float sum = 0;
uint32_t sumCount = 0;

Ticker log_ticker;              // creates ticker
FILE *fp;                       // defines file
char file_name[100];            // creates file name character

void mpu9250_initialization(){
    pc.printf("####CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock);  
    //initial com check
    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\r", whoami); pc.printf("I SHOULD BE 0x71\n\r");
    if (whoami == 0x71) // WHO_AM_I should always be 0x68
    {  
        pc.printf("####MPU9250 WHO_AM_I is 0x%x\n\r", whoami);
        pc.printf("####MPU9250 is online...\n\r");
        wait(1);
        //reset MPU and conduct self test//
        pc.printf("####Please wait,IMU Resetting####\r\n");
        mpu9250.resetMPU9250(); // Reset registers to default in preparation for device calibration
        pc.printf("####Self Test####\r\n");
        //initial MPU9250 Parameters
        mpu9250.Ascale = AFS_2G;
        mpu9250.Gscale = GFS_250DPS;               // GFS_250DPS, GFS_500DPS, GFS_1000DPS, GFS_2000DPS
        mpu9250.Mscale = MFS_16BITS;               // MFS_14BITS or MFS_16BITS, 14-bit or 16-bit magnetometer resolution
        mpu9250.Mmode = 0x06;
        mpu9250.delt_t=0;
        mpu9250.deltat=0.0f;
        mpu9250.lastUpdate = 0;
        mpu9250.firstUpdate = 0;
        mpu9250.Now = 0;
        mpu9250.count=0;
        mpu9250.q[0] = 1.0f;
        mpu9250.q[1] = 0.0f;
        mpu9250.q[2] = 0.0f;
        mpu9250.q[3] = 0.0f;
        // mpu9250.MPU9250SelfTest(SelfTest); // Start by performing self test and reporting values
        //pc.printf("x-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[0]);  
        // pc.printf("y-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[1]);  
        //pc.printf("z-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[2]);  
        //pc.printf("x-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[3]);  
        //pc.printf("y-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[4]);  
        //pc.printf("z-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[5]);  
        pc.printf("####Gyro and accelerometer Calibration will start in 5 seconds####\r\n");
        pc.printf("####Please keep the IMU still\r\n");
        wait(5);
        pc.printf("####Calibration starts\r\n");
        mpu9250.calibrateMPU9250(mpu9250.gyroBias, mpu9250.accelBias); // Calibrate gyro and accelerometers, load biases in bias registers  
        pc.printf("x gyro bias = %f\n\r", mpu9250.gyroBias[0]);
        pc.printf("y gyro bias = %f\n\r", mpu9250.gyroBias[1]);
        pc.printf("z gyro bias = %f\n\r", mpu9250.gyroBias[2]);
        pc.printf("x accel bias = %f\n\r", mpu9250.accelBias[0]);
        pc.printf("y accel bias = %f\n\r", mpu9250.accelBias[1]);
        pc.printf("z accel bias = %f\n\r", mpu9250.accelBias[2]);
        wait(2);
        ///initialization
        mpu9250.initMPU9250();
        pc.printf("MPU9250 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
        mpu9250.initAK8963(mpu9250.magCalibration);
        pc.printf("Magnetometer initilized\r\n");
       // pc.printf("AK8963 initialized for active data mode....\n\r"); // Initialize device for active mode read of magnetometer
       // pc.printf("Accelerometer full-scale range = %f  g\n\r", 2.0f*(float)(1<<Ascale));
       // pc.printf("Gyroscope full-scale range = %f  deg/s\n\r", 250.0f*(float)(1<<Gscale));
        if(mpu9250.Mscale == 0) pc.printf("Magnetometer resolution = 14  bits\n\r");
        if(mpu9250.Mscale == 1) pc.printf("Magnetometer resolution = 16  bits\n\r");
        if(mpu9250.Mmode == 2) pc.printf("Magnetometer ODR = 8 Hz\n\r");
        if(mpu9250.Mmode == 6) pc.printf("Magnetometer ODR = 100 Hz\n\r");
    }
    else
    {
        pc.printf("Could not connect to MPU9250: \n\r");
        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
    pc.printf("Accelerometer sensitivity is %f LSB/g \n\r", 1.0f/mpu9250.aRes);
    pc.printf("Gyroscope sensitivity is %f LSB/deg/s \n\r", 1.0f/mpu9250.gRes);
    pc.printf("Magnetometer sensitivity is %f LSB/G \n\r", 1.0f/mpu9250.mRes);
    pc.printf("####IMU initialization done####\r\n");
    wait(1);
}


void mag_cali(){
    int32_t mag_bias[3] = {0, 0, 0}, mag_scale[3] = {0, 0, 0};
    int16_t mag_max[3] = {-32767, -32767, -32767}, mag_min[3] = {32767, 32767, 32767}, mag_temp[3] = {0, 0, 0};
    //float dest1[3]={0,0,0}, dest2[3]={0,0,0};
    pc.printf("####Compass Calibration starts in 5 seconds\r\n");
    wait(5);
    pc.printf("###Start moving your imu in figure 8\r\n");
    for (int i=0;i<1500;i++){   //1500 for 100 Hz          
            mpu9250.readMagData(mag_temp);  // Read the x/y/z adc values  
            for(int jj=0; jj<3; jj++){
            if(mag_temp[jj] > mag_max[jj]) mag_max[jj] = mag_temp[jj];
            if(mag_temp[jj] < mag_min[jj]) mag_min[jj] = mag_temp[jj];
            }
            wait(0.01);//delay for 10 ms.
    }
    //get hard iron correction
    // Get hard iron correction
    mag_bias[0]  = (mag_max[0] + mag_min[0])/2;  // get average x mag bias in counts
    mag_bias[1]  = (mag_max[1] + mag_min[1])/2;  // get average y mag bias in counts
    mag_bias[2]  = (mag_max[2] + mag_min[2])/2;  // get average z mag bias in counts
    mpu9250.magbias[0] = (float) mag_bias[0]*mpu9250.mRes*mpu9250.magCalibration[0];  // save mag biases in G for main program
    mpu9250.magbias[1] = (float) mag_bias[1]*mpu9250.mRes*mpu9250.magCalibration[1];  
    mpu9250.magbias[2] = (float) mag_bias[2]*mpu9250.mRes*mpu9250.magCalibration[2];  
    pc.printf("####Mag bias =%f,%f,%f\r\n",mpu9250.magbias[0],mpu9250.magbias[1],mpu9250.magbias[2]);
    /*//get soft iron correction
    // Get soft iron correction estimate
    mag_scale[0]  = (mag_max[0] - mag_min[0])/2;  // get average x axis max chord length in counts
    mag_scale[1]  = (mag_max[1] - mag_min[1])/2;  // get average y axis max chord length in counts
    mag_scale[2]  = (mag_max[2] - mag_min[2])/2;  // get average z axis max chord length in counts
   
    float avg_rad = mag_scale[0] + mag_scale[1] + mag_scale[2];
    avg_rad /= 3.0;
   
    dest2[0] = avg_rad/((float)mag_scale[0]);
    dest2[1] = avg_rad/((float)mag_scale[1]);
    dest2[2] = avg_rad/((float)mag_scale[2]);
    */
    pc.printf("####Mag Calibration done!\r\n");
}

void sdwrite1(){        // Writes first set to SD & to Coolterm to confirm data
    fprintf(fp,"$IMUPS,%f,%f,%f,%f\r\n",t.read(),mpu9250.roll,mpu9250.pitch,mpu9250.yaw);
    pc.printf("$IMUPS,%f,%f,%f,%f\r\n",t.read(),mpu9250.roll,mpu9250.pitch,mpu9250.yaw);
}

void sdwrite2(){        // Writes 2nd set to SD & Coolterm
    fprintf(fp,"$GPSST,%d,%f,%d\r\n",gps.lock,gps.utc_time,gps.satelites);
    pc.printf("$GPSST,%d,%f,%d\r\n",gps.lock,gps.utc_time,gps.satelites);
}

void sdwrite3(){        // Writes 3rd set to SD & Coolterm
    fprintf(fp,"$GPSPS,%f,%f,%f,%f,%f\r\n",t.read(),gps.nmea_latitude,gps.nmea_longitude,gps.speed_k,gps.course_d);
    pc.printf("$GPSPS,%f,%f,%f,%f,%f\r\n",t.read(),gps.nmea_latitude,gps.nmea_longitude,gps.speed_k,gps.course_d);
}


int main() {
    char buffer[100];                                           // creates buffer character
    mkdir("/sd/A5_Beason", 0777);                                   // file location
    pc.printf("Please set a file name\r\n");                    // asks user for file name
    pc.scanf("%s",buffer);                                      // looks at the name given
    sprintf(file_name,"/sd/A5_Beason/%s.txt",buffer);               // creates file location
    pc.printf("The file name and directory is: %s\r\n",file_name);  // tells user the information
    fp = fopen(file_name, "w");     // opens file to be written on
    pc.printf("file_opened \n");    // tells user the file is opened
    if (fp == NULL) {               // if the file is not opened
        error("Could not open file for writing\n"); // informs user that the file was not opened
    }
    fclose(fp);                     // closes file
   
    pc.baud(9600);
    t.start();  
    mpu9250_initialization();
    mag_cali();
    pc.printf("####IMU is all set, going to start sensing in 5 seconds\r\n");
    wait(5);
    while(1){
        if(mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) {  // On interrupt, check if data ready interrupt
            mpu9250.readAccelData(mpu9250.accelCount);  // Read the x/y/z adc values  
            // Now we'll calculate the accleration value into actual g's
            mpu9250.ax = (float)mpu9250.accelCount[0]*mpu9250.aRes - mpu9250.accelBias[0];  // get actual g value, this depends on scale being set
            mpu9250.ay = (float)mpu9250.accelCount[1]*mpu9250.aRes - mpu9250.accelBias[1];  
            mpu9250.az = (float)mpu9250.accelCount[2]*mpu9250.aRes - mpu9250.accelBias[2];  
           
            mpu9250.readGyroData(mpu9250.gyroCount);  // Read the x/y/z adc values
            // Calculate the gyro value into actual degrees per second
            mpu9250.gx = (float)mpu9250.gyroCount[0]*mpu9250.gRes - mpu9250.gyroBias[0];  // get actual gyro value, this depends on scale being set
            mpu9250.gy = (float)mpu9250.gyroCount[1]*mpu9250.gRes - mpu9250.gyroBias[1];  
            mpu9250.gz = (float)mpu9250.gyroCount[2]*mpu9250.gRes - mpu9250.gyroBias[2];  
         
            mpu9250.readMagData(mpu9250.magCount);  // Read the x/y/z adc values  
            // Calculate the magnetometer values in milliGauss
            // Include factory calibration per data sheet and user environmental corrections
            mpu9250.mx = (float)mpu9250.magCount[0]*mpu9250.mRes*mpu9250.magCalibration[0] - mpu9250.magbias[0];  // get actual magnetometer value, this depends on scale being set
            mpu9250.my = (float)mpu9250.magCount[1]*mpu9250.mRes*mpu9250.magCalibration[1] - mpu9250.magbias[1];  
            mpu9250.mz = (float)mpu9250.magCount[2]*mpu9250.mRes*mpu9250.magCalibration[2] - mpu9250.magbias[2];  
        }
       
        mpu9250.Now = t.read_us();
        mpu9250.deltat = (float)((mpu9250.Now - mpu9250.lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update
        mpu9250.lastUpdate = mpu9250.Now;
        sum += mpu9250.deltat;
        sumCount++;
        //mpu9250.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f,  mx,  my, mz);
        //compute the quaternion.

         mpu9250.MahonyQuaternionUpdate(mpu9250.ax, mpu9250.ay, mpu9250.az,
                                       mpu9250.gx*PI/180.00, mpu9250.gy*PI/180.00, mpu9250.gz*PI/180.00,
                                       mpu9250.mx, mpu9250.my, mpu9250.mz);

           //    pc.printf("Q=%f,%f,%f,%f\r\n",mpu9250.q[0],mpu9250.q[1],mpu9250.q[2],mpu9250.q[3]);
        // Serial print and/or display at 0.5 s rate independent of data rates
        mpu9250.delt_t = t.read_ms() - mpu9250.count;
        if (mpu9250.delt_t > 100) {
//            pc.printf("ax = %f", 1000*mpu9250.ax);
//            pc.printf(" ay = %f", 1000*mpu9250.ay);
//            pc.printf(" az = %f  mg\n\r", 1000*mpu9250.az);
//            pc.printf("gx = %f", mpu9250.gx);
//            pc.printf("gy = %f", mpu9250.gy);
//            pc.printf("gz = %f  deg/s\n\r", mpu9250.gz);
            //pc.printf("mx = %f", mpu9250.mx);
            //pc.printf(" my = %f", mpu9250.my);
            //pc.printf(" mz = %f  mG\n\r", mpu9250.mz);
//            tempCount = mpu9250.readTempData();  // Read the adc values
//            temperature = ((float) tempCount) / 333.87f + 21.0f; // Temperature in degrees Centigrade
//            pc.printf(" temperature = %f  C\n\r", temperature);
           
            mpu9250.roll  = atan2(2.0f * (mpu9250.q[0] * mpu9250.q[1] + mpu9250.q[2] * mpu9250.q[3]),
                                  mpu9250.q[0] * mpu9250.q[0] - mpu9250.q[1] * mpu9250.q[1] - mpu9250.q[2] * mpu9250.q[2] + mpu9250.q[3] * mpu9250.q[3]);
            mpu9250.pitch = -asin(2.0f * (mpu9250.q[1] * mpu9250.q[3] - mpu9250.q[0] * mpu9250.q[2]));
            mpu9250.yaw   = atan2(2.0f * (mpu9250.q[1] * mpu9250.q[2] + mpu9250.q[0] * mpu9250.q[3]),
                                  mpu9250.q[0] * mpu9250.q[0] + mpu9250.q[1] * mpu9250.q[1] - mpu9250.q[2] * mpu9250.q[2] - mpu9250.q[3] * mpu9250.q[3]);  
            mpu9250.pitch *= 180.0f / PI;
            mpu9250.yaw   *= 180.0f / PI;
            mpu9250.yaw   += 15.0f; // Declination at RI
            mpu9250.roll  *= 180.0f / PI;
           
            fp = fopen(file_name,"a");      // Open file
                       
            sdwrite1();                 // Write $IMUPS to SD card
            sdwrite2();                 // Write $GPSST to SD card
            sdwrite3();                 // Write $GPSPS to SD card
            fclose(fp);                                     // close file
           
            myled= !myled;
            mpu9250.count = t.read_ms();

            if(mpu9250.count > 1<<21) {
                t.start(); // start the timer over again if ~30 minutes has passed
                mpu9250.count = 0;
                mpu9250.deltat= 0;
                mpu9250.lastUpdate = t.read_us();
            }
            sum = 0;
            sumCount = 0;
           
            pc.printf("lock=%d %f %f %c %f %c %f %f\r\n",gps.lock,gps.utc_time,gps.nmea_longitude,gps.ns,gps.nmea_latitude,gps.ew,gps.speed_k,gps.course_d);
            wait(1);
        }
   
    }    

}