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/*
HMC5843_basic.pde - Basic reading example for the HMC5843 library
Copyright (C) 2011 Fabio Varesano <fabio at varesano dot net>
This program is free software: you can redistribute it and/or modify
it under the terms of the version 3 GNU General Public License as
published by the Free Software Foundation.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <Wire.h>
//#include <DebugUtils.h>
#include <HMC58X3.h>
HMC58X3 magn;
void setup(void) {
Serial.begin(9600);
Wire.begin();
// no delay needed as we have already a delay(5) in HMC5843::init()
magn.init(false); // Dont set mode yet, we'll do that later on.
// Calibrate HMC using self test, not recommended to change the gain after calibration.
magn.calibrate(1, 32); // Use gain 1=default, valid 0-7, 7 not recommended.
// Single mode conversion was used in calibration, now set continuous mode
magn.setMode(0);
}
void loop() {
int ix,iy,iz;
float fx,fy,fz;
delay(10);
// Get values, as ints and floats.
magn.getValues(&ix,&iy,&iz);
magn.getValues(&fx,&fy,&fz);
// also available HMC5843::getValues(float *xyz) you can pass to it an array of 3 floats
// Print int values
Serial.print("Ints x:");
Serial.print(ix);
Serial.print(",");
Serial.print(iy);
Serial.print(",");
Serial.print(iz);
Serial.print(",");
// Print float values
Serial.print(" Floats x:");
Serial.print(fx);
Serial.print(" y:");
Serial.print(fy);
Serial.print(" z:");
Serial.print(fz);
// a simple heading, assuming it's close to horizontal. See:
// M.J. Caruso. Applications of magnetic sensors for low cost compass systems.
// In Position Location and Navigation Symposium, IEEE, 2000. Available from:
// http://hnc.ru/lib/a%26c%20%28automatic%20%26%20controls%29/sensors/DataSheet/Magnit/Honeywell/lowcost.pdf
Serial.print(" Heading: ");
float heading = atan2(fy, fx);
if(heading < 0) {
heading += 2 * M_PI;
}
Serial.println(heading * 180/M_PI);
// x and y axis are swapped above with respect to the above paper as our Z axis points to the sky while in the paper it points to the bottom
}