Mbed electronic "bubble level." Uses LSB9DS1 9-degrees-of-freedom IMU to determine orientation and prints bubble display to LCD screen.

Dependencies:   4DGL-uLCD-SE LSM9DS1_Library_cal mbed

main.cpp

Committer:
wschon
Date:
2016-02-13
Revision:
0:8079f51a9835

File content as of revision 0:8079f51a9835:

#include "mbed.h"
#include "LSM9DS1.h"
#include "uLCD_4DGL.h"
#define PI 3.14159
// Earth's magnetic field varies by location. Add or subtract
// a declination to get a more accurate heading. Calculate
// your's here:
// http://www.ngdc.noaa.gov/geomag-web/#declination
#define DECLINATION -4.94 // Declination (degrees) in Atlanta,GA.

DigitalOut myled(LED1);
Serial pc(USBTX, USBRX);
float accel_x, accel_y, accel_z;
int outer_radius = 9;
int radius = 3;
uLCD_4DGL uLCD(p9,p10,p11); // serial tx, serial rx, reset pin;
int x,y;

// Calculate pitch, roll, and heading.
// Pitch/roll calculations taken from this app note:
// http://cache.freescale.com/files/sensors/doc/app_note/AN3461.pdf?fpsp=1
// Heading calculations taken from this app note:
// http://www51.honeywell.com/aero/common/documents/myaerospacecatalog-documents/Defense_Brochures-documents/Magnetic__Literature_Application_notes-documents/AN203_Compass_Heading_Using_Magnetometers.pdf
void printAttitude(float ax, float ay, float az, float mx, float my, float mz)
{
    float roll = atan2(ay, az);
    float pitch = atan2(-ax, sqrt(ay * ay + az * az));
// touchy trig stuff to use arctan to get compass heading (scale is 0..360)
    mx = -mx;
    float heading;
    if (my == 0.0)
        heading = (mx < 0.0) ? 180.0 : 0.0;
    else
        heading = atan2(mx, my)*360.0/(2.0*PI);
    //pc.printf("heading atan=%f \n\r",heading);
    heading -= DECLINATION; //correct for geo location
    if(heading>180.0) heading = heading - 360.0;
    else if(heading<-180.0) heading = 360.0 + heading;
    else if(heading<0.0) heading = 360.0  + heading;


    // Convert everything from radians to degrees:
    //heading *= 180.0 / PI;
    pitch *= 180.0 / PI;
    roll  *= 180.0 / PI;

    pc.printf("Pitch: %f,    Roll: %f degress\n\r",pitch,roll);
    pc.printf("Magnetic Heading: %f degress\n\r",heading);
}




int main()
{
    // basic printf demo = 16 by 18 characters on screen
    
    //LSM9DS1 lol(p9, p10, 0x6B, 0x1E);
    LSM9DS1 IMU(p28, p27, 0xD6, 0x3C);
    IMU.begin();
    if (!IMU.begin()) {
        pc.printf("Failed to communicate with LSM9DS1.\n");
    }
    IMU.calibrate(1);
    IMU.calibrateMag(0);
    while(1) {
        while(!IMU.tempAvailable());
        IMU.readTemp();
        while(!IMU.magAvailable(X_AXIS));
        IMU.readMag();
        while(!IMU.accelAvailable());
        IMU.readAccel();
        while(!IMU.gyroAvailable());
        IMU.readGyro();
        pc.printf("\nIMU Temperature = %f C\n\r",25.0 + IMU.temperature/16.0);
        pc.printf("        X axis    Y axis    Z axis\n\r");
        pc.printf("gyro:  %9f %9f %9f in deg/s\n\r", IMU.calcGyro(IMU.gx), IMU.calcGyro(IMU.gy), IMU.calcGyro(IMU.gz));
        pc.printf("accel: %9f %9f %9f in Gs\n\r", IMU.calcAccel(IMU.ax), IMU.calcAccel(IMU.ay), IMU.calcAccel(IMU.az));
        pc.printf("mag:   %9f %9f %9f in gauss\n\r", IMU.calcMag(IMU.mx), IMU.calcMag(IMU.my), IMU.calcMag(IMU.mz));
        printAttitude(IMU.calcAccel(IMU.ax), IMU.calcAccel(IMU.ay), IMU.calcAccel(IMU.az), IMU.calcMag(IMU.mx),
                      IMU.calcMag(IMU.my), IMU.calcMag(IMU.mz));
        myled = 1;
        wait(2.5);
        myled = 0;
        wait(0.5);

        while(1) {
            while(!IMU.accelAvailable());
            IMU.readAccel();
            accel_x = IMU.calcAccel(IMU.ax);
            accel_y = IMU.calcAccel(IMU.ay);
            accel_z = IMU.calcAccel(IMU.az);
            pc.printf("accel: %9f %9f %9f in Gs\n\r", IMU.calcAccel(IMU.ax), IMU.calcAccel(IMU.ay), IMU.calcAccel(IMU.az));
            //draw ball
            x = 64 + 64*accel_x;
            y = 64 + 64*accel_y;
            uLCD.circle(64, 64, outer_radius, RED);
            uLCD.filled_circle(x,y, radius, BLUE);
            //bounce off edge walls and slow down a bit?
           // if ((x<=radius+1) || (x>=126-radius)) vx = -.90*vx;
           // if ((y<=radius+1) || (y>=126-radius)) vy = -.90*vy;
            //erase old ball location
          //  uLCD.filled_circle(x, y, radius, BLACK);
            //move ball
          //  fx=fx+vx;
           // fy=fy+vy;
         //   x=(int)fx;
         //   y=(int)fy;
            wait(0.1);
           uLCD.filled_circle(x,y, radius, BLACK);

        }
    }
}