File content as of revision 1:2d4aa9e794a5:

#include "mbed.h"
#include "HSCDTD008A.h"

#define M_PI  3.14159265358979323846

HSCDTD008A  compass(PB_7, PB_6);
Watchdog&   watchdog = Watchdog::get_instance();

int main()
{
    float   x_sum;
    float   y_sum;
    float   z_sum;
    float   x_avg;
    float   y_avg;
    float   z_avg;
    float   bearing;

    printf("Starting selftest.. ");
    if (compass.selfTest() == OK) {
        printf("passed\r\n");
    }
    else {
        printf("failed\r\n");
    }

    printf("Calibrating offsets.. ");
    compass.calibrateOffsets();

    printf("done\r\n");

    printf("Compensating temperature.. ");
    compass.compensateTemp();
    printf("done\r\n");

    ThisThread::sleep_for(1000ms);

    compass.setResolution(true);    // set 15bit resolution
    printf("res = %d\r\n", compass.getResolution());

    compass.enableFifo();
    compass.normalMode(0b10);

    watchdog.start(3000);

    while (true) {
        printf("-----------------\r\n");
        printf("Measuring.. \r\n");

        if (compass.isFifoFull()) {
           watchdog.kick();

            //printf("FIFO pointer = %d\r\n", compass.fifoPointer());
            //printf("FIFO full = %d\r\n", compass.isFifoFull());

           // get data and calculate sums
            x_sum = 0;
            y_sum = 0;
            z_sum = 0;

            for (uint8_t i = 0; i < 8; i++) {
                compass.readData();
                x_sum += compass.x();
                y_sum += compass.y();
                z_sum += compass.z();
            }

            // calculate averages
            x_avg = x_sum / 8;
            y_avg = y_sum / 8;
            z_avg = z_sum / 8;

            //printf("FIFO pointer = %d\r\n", compass.fifoPointer());
            //printf("FIFO full = %d\r\n", compass.isFifoFull());
            //printf("\r\n");

            printf("x_avg = %f\r\n", x_avg);
            printf("y_avg = %f\r\n", y_avg);
            printf("z_avg = %f\r\n", z_avg);
            printf("\r\n");

            bearing = atan2(y_avg, x_avg) * 180 / M_PI;
            if (bearing < 0) {
                bearing = 360 + bearing;
            };

            printf("bearing = %f\r\n", bearing);
        }

        ThisThread::sleep_for(1s);
    }
}