IMU demo
Dependencies: LSM9DS1_Library_cal mbed
Revision 0:9a033a3d8481, committed 2017-02-09
- Comitter:
- gkang34
- Date:
- Thu Feb 09 19:46:20 2017 +0000
- Commit message:
- IMU calibrates and outputs angle
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/LSM9DS1_Library_cal.lib Thu Feb 09 19:46:20 2017 +0000 @@ -0,0 +1,1 @@ +https://developer.mbed.org/users/4180_1/code/LSM9DS1_Library_cal/#36abf8e18ade
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Thu Feb 09 19:46:20 2017 +0000 @@ -0,0 +1,97 @@ +#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(p9, p10, 0xD6, 0x3C); + IMU.begin(); + if (!IMU.begin()) { + pc.printf("Failed to communicate with LSM9DS1.\n"); + } + IMU.calibrate(1); + + // init a0 + float ax0 = IMU.calcAccel(IMU.ax); + float ay0 = IMU.calcAccel(IMU.ay); + float az0 = IMU.calcAccel(IMU.az); + + //IMU.calibrateMag(0); + while(1) { + + while(!IMU.accelAvailable()); + IMU.readAccel(); + + // current a = <ax,ay,az> + float ax = IMU.calcAccel(IMU.ax); + float ay = IMU.calcAccel(IMU.ay); + float az = IMU.calcAccel(IMU.az); + // theta in degrees between a0 and a + float theta = acos((ax0*ax + ay0*ay + az0*az)/(sqrt(ax0*ax0+ay0*ay0+az0*az0)*sqrt(ax*ax+ay*ay+az*az)))*180/PI; + + //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)); + pc.printf("angle: %9f in degrees\n\r", theta); + myled = 1; + wait(0.5); + myled = 0; + wait(0.5); + } +} +
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Thu Feb 09 19:46:20 2017 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/176b8275d35d \ No newline at end of file