Diff: main.cpp

Revision:

0:e693d5bf0a25

Child:

1:736628381fb9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Feb 03 18:47:07 2016 +0000
@@ -0,0 +1,79 @@
+#include "mbed.h"
+#include "LSM9DS1.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);
+// 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()
+{
+    //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(0.5);
+        myled = 0;
+        wait(0.5);
+    }
+}
+