4180 LabTeam - Spring '18 / Mbed 2 deprecated LSM9DS1_Demo_wCal

IMU Code

Dependencies:   LSM9DS1_Library_cal mbed

Fork of LSM9DS1_Demo_wCal by Barry Johnson-Smith

main.cpp@1:ce85d6bf743f, 2018-02-08 (annotated)

Committer:
bjs9
Date:
Thu Feb 08 03:52:24 2018 +0000
Revision:
1:ce85d6bf743f
Parent:
0:e693d5bf0a25 
IMU code;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
4180_1 0:e693d5bf0a25 1 #include "mbed.h"
4180_1 0:e693d5bf0a25 2 #include "LSM9DS1.h"
4180_1 0:e693d5bf0a25 3 #define PI 3.14159
4180_1 0:e693d5bf0a25 4 // Earth's magnetic field varies by location. Add or subtract
4180_1 0:e693d5bf0a25 5 // a declination to get a more accurate heading. Calculate
4180_1 0:e693d5bf0a25 6 // your's here:
4180_1 0:e693d5bf0a25 7 // http://www.ngdc.noaa.gov/geomag-web/#declination
4180_1 0:e693d5bf0a25 8 #define DECLINATION -4.94 // Declination (degrees) in Atlanta,GA.
4180_1 0:e693d5bf0a25 9
4180_1 0:e693d5bf0a25 10 DigitalOut myled(LED1);
4180_1 0:e693d5bf0a25 11 Serial pc(USBTX, USBRX);
4180_1 0:e693d5bf0a25 12 // Calculate pitch, roll, and heading.
4180_1 0:e693d5bf0a25 13 // Pitch/roll calculations taken from this app note:
4180_1 0:e693d5bf0a25 14 // http://cache.freescale.com/files/sensors/doc/app_note/AN3461.pdf?fpsp=1
4180_1 0:e693d5bf0a25 15 // Heading calculations taken from this app note:
4180_1 0:e693d5bf0a25 16 // http://www51.honeywell.com/aero/common/documents/myaerospacecatalog-documents/Defense_Brochures-documents/Magnetic__Literature_Application_notes-documents/AN203_Compass_Heading_Using_Magnetometers.pdf
4180_1 0:e693d5bf0a25 17 void printAttitude(float ax, float ay, float az, float mx, float my, float mz)
4180_1 0:e693d5bf0a25 18 {
4180_1 0:e693d5bf0a25 19 float roll = atan2(ay, az);
4180_1 0:e693d5bf0a25 20 float pitch = atan2(-ax, sqrt(ay * ay + az * az));
4180_1 0:e693d5bf0a25 21 // touchy trig stuff to use arctan to get compass heading (scale is 0..360)
4180_1 0:e693d5bf0a25 22 mx = -mx;
4180_1 0:e693d5bf0a25 23 float heading;
4180_1 0:e693d5bf0a25 24 if (my == 0.0)
4180_1 0:e693d5bf0a25 25 heading = (mx < 0.0) ? 180.0 : 0.0;
4180_1 0:e693d5bf0a25 26 else
4180_1 0:e693d5bf0a25 27 heading = atan2(mx, my)*360.0/(2.0*PI);
4180_1 0:e693d5bf0a25 28 //pc.printf("heading atan=%f \n\r",heading);
4180_1 0:e693d5bf0a25 29 heading -= DECLINATION; //correct for geo location
4180_1 0:e693d5bf0a25 30 if(heading>180.0) heading = heading - 360.0;
4180_1 0:e693d5bf0a25 31 else if(heading<-180.0) heading = 360.0 + heading;
4180_1 0:e693d5bf0a25 32 else if(heading<0.0) heading = 360.0 + heading;
4180_1 0:e693d5bf0a25 33
4180_1 0:e693d5bf0a25 34
4180_1 0:e693d5bf0a25 35 // Convert everything from radians to degrees:
4180_1 0:e693d5bf0a25 36 //heading *= 180.0 / PI;
4180_1 0:e693d5bf0a25 37 pitch *= 180.0 / PI;
4180_1 0:e693d5bf0a25 38 roll *= 180.0 / PI;
4180_1 0:e693d5bf0a25 39
4180_1 0:e693d5bf0a25 40 pc.printf("Pitch: %f, Roll: %f degress\n\r",pitch,roll);
4180_1 0:e693d5bf0a25 41 pc.printf("Magnetic Heading: %f degress\n\r",heading);
4180_1 0:e693d5bf0a25 42 }
4180_1 0:e693d5bf0a25 43
4180_1 0:e693d5bf0a25 44
4180_1 0:e693d5bf0a25 45
4180_1 0:e693d5bf0a25 46
4180_1 0:e693d5bf0a25 47 int main()
4180_1 0:e693d5bf0a25 48 {
4180_1 0:e693d5bf0a25 49 //LSM9DS1 lol(p9, p10, 0x6B, 0x1E);
bjs9 1:ce85d6bf743f 50 LSM9DS1 IMU(p9, p10, 0xD6, 0x3C);
4180_1 0:e693d5bf0a25 51 IMU.begin();
4180_1 0:e693d5bf0a25 52 if (!IMU.begin()) {
4180_1 0:e693d5bf0a25 53 pc.printf("Failed to communicate with LSM9DS1.\n");
4180_1 0:e693d5bf0a25 54 }
4180_1 0:e693d5bf0a25 55 IMU.calibrate(1);
4180_1 0:e693d5bf0a25 56 IMU.calibrateMag(0);
4180_1 0:e693d5bf0a25 57 while(1) {
4180_1 0:e693d5bf0a25 58 while(!IMU.tempAvailable());
4180_1 0:e693d5bf0a25 59 IMU.readTemp();
4180_1 0:e693d5bf0a25 60 while(!IMU.magAvailable(X_AXIS));
4180_1 0:e693d5bf0a25 61 IMU.readMag();
4180_1 0:e693d5bf0a25 62 while(!IMU.accelAvailable());
4180_1 0:e693d5bf0a25 63 IMU.readAccel();
4180_1 0:e693d5bf0a25 64 while(!IMU.gyroAvailable());
4180_1 0:e693d5bf0a25 65 IMU.readGyro();
4180_1 0:e693d5bf0a25 66 pc.printf("\nIMU Temperature = %f C\n\r",25.0 + IMU.temperature/16.0);
4180_1 0:e693d5bf0a25 67 pc.printf(" X axis Y axis Z axis\n\r");
4180_1 0:e693d5bf0a25 68 pc.printf("gyro: %9f %9f %9f in deg/s\n\r", IMU.calcGyro(IMU.gx), IMU.calcGyro(IMU.gy), IMU.calcGyro(IMU.gz));
4180_1 0:e693d5bf0a25 69 pc.printf("accel: %9f %9f %9f in Gs\n\r", IMU.calcAccel(IMU.ax), IMU.calcAccel(IMU.ay), IMU.calcAccel(IMU.az));
4180_1 0:e693d5bf0a25 70 pc.printf("mag: %9f %9f %9f in gauss\n\r", IMU.calcMag(IMU.mx), IMU.calcMag(IMU.my), IMU.calcMag(IMU.mz));
4180_1 0:e693d5bf0a25 71 printAttitude(IMU.calcAccel(IMU.ax), IMU.calcAccel(IMU.ay), IMU.calcAccel(IMU.az), IMU.calcMag(IMU.mx),
4180_1 0:e693d5bf0a25 72 IMU.calcMag(IMU.my), IMU.calcMag(IMU.mz));
4180_1 0:e693d5bf0a25 73 myled = 1;
4180_1 0:e693d5bf0a25 74 wait(0.5);
4180_1 0:e693d5bf0a25 75 myled = 0;
4180_1 0:e693d5bf0a25 76 wait(0.5);
4180_1 0:e693d5bf0a25 77 }
4180_1 0:e693d5bf0a25 78 }
4180_1 0:e693d5bf0a25 79