File content as of revision 4:3618abce1646:

#include "mbed.h"
#include "SSD1306_mini.h"
#include "MMC5883L.h"

SSD1306_mini_swspi gOled1(PA_5, PA_7,PA_3,PA_4,PA_2);
// SSD1306_mini_swspi(PinName D0, PinName D1, PinName DC, PinName RST, PinName CS)

MMC5883L compass(PF_0, PF_1);

int main() {
    
    wait(0.1f);
    compass.init();
    wait(0.1f);
    int16_t data[3] = {0,0,0};
    
    while(1) {
        double heading = compass.getHeadingXY(data);
        double Btot = sqrt(pow((double)data[0],2) + pow((double)data[1],2) + pow((double)data[2],2)); 

        
        int16_t compassRadius  = gOled1.height()/2-1;
        int16_t compassCenterX = gOled1.width()/2;
        int16_t compassCenterY = gOled1.height()/2;

        gOled1.clearDisplay();
        char str[20];
        
        int32_t xyz_nt[3];
        compass.getXYZ_OffsetRemoved_nT(xyz_nt);
        
        gOled1.setTextCursor(0, 5);

        gOled1.printf("X: %i", xyz_nt[0]);;
        
        gOled1.setTextCursor(0, 15);

        gOled1.printf("Y: %i", xyz_nt[1]);
        
        gOled1.setTextCursor(0, 25);

        gOled1.printf("Z: %i", xyz_nt[2]);
        

        /*
        gOled1.printf("MMC5883        kompas\r\n");
        

            gOled1.drawCircle(compassCenterX, compassCenterY, compassRadius, WHITE );
            gOled1.fillCircle(compassCenterX, compassCenterY, 2, WHITE );

            gOled1.drawLine(compassCenterX, compassCenterY+18, compassCenterX, compassCenterY+20, WHITE);
            gOled1.drawLine(compassCenterX, compassCenterY-18, compassCenterX, compassCenterY-20, WHITE);
            gOled1.drawLine(compassCenterX+18, compassCenterY, compassCenterX+20, compassCenterY, WHITE);
            gOled1.drawLine(compassCenterX-18, compassCenterY, compassCenterX-20, compassCenterY, WHITE);

            double x_vect = cos(heading)* compassRadius;
            double y_vect = sin(heading)* compassRadius;

            gOled1.drawLine(compassCenterX, compassCenterY, (int16_t) (compassCenterX + x_vect), (int16_t) (compassCenterY - y_vect), WHITE);
            
            gOled1.setTextCursor(compassCenterX-2, compassCenterY-compassRadius);
            gOled1.printf("S");
            gOled1.setTextCursor(compassCenterX-2, compassCenterY+compassRadius-7);
            gOled1.printf("J");
            gOled1.setTextCursor(compassCenterX-compassRadius-2, compassCenterY-3);
            gOled1.printf("Z");
            gOled1.setTextCursor(compassCenterX+compassRadius-2, compassCenterY-3);
            gOled1.printf("V");

            gOled1.setTextCursor(0, gOled1.height()-18);
            gOled1.printf("FEL");
            gOled1.setTextCursor(17*6, gOled1.height()-18);
            gOled1.printf("CVUT");

            gOled1.setTextCursor(0, gOled1.height()-8);
            gOled1.printf("LPE");
            gOled1.setTextCursor(17*6, gOled1.height()-8);
            gOled1.printf("2021");
 //       }        */
        gOled1.display();
        wait(0.05f);
    }
}