File content as of revision 6:cbeb4c54830c:

/**
@file HMC58X3.h - Interface a Honeywell HMC58X3 magnetometer to an Arduino via i2c.

@author Fabio Varesano <fvaresano@yahoo.it>
Copyright (C) 2011 Fabio Varesano <fvaresano@yahoo.it>
ported for Mbed by Aloïs Wolff

Based on:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1274748346
  Modification/extension of the following by E.J.Muller
http://eclecti.cc/hardware/hmc5843-magnetometer-library-for-arduino
  Copyright (c) 2009 Nirav Patel,

The above were based on:
http://www.sparkfun.com/datasheets/Sensors/Magneto/HMC58X3-v11.c
http://www.atmel.com/dyn/resources/prod_documents/doc2545.pdf

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/>.
*/

//#define ISHMC5843 (1) // Uncomment this following line if you are using this library with the HMC5843.
#include "Global.h"


#ifndef HMC58X3_h
#define HMC58X3_h

#ifndef I2C_SDA
    #define I2C_SDA p28
    #define I2C_SCL p27
#endif

#define HMC58X3_ADDR 0x1E // 7 bit address of the HMC58X3 used with the Wire library
#define HMC_POS_BIAS 1
#define HMC_NEG_BIAS 2

// HMC58X3 register map. For details see HMC58X3 datasheet
#define HMC58X3_R_CONFA 0
#define HMC58X3_R_CONFB 1
#define HMC58X3_R_MODE 2
#define HMC58X3_R_XM 3
#define HMC58X3_R_XL 4

#ifdef ISHMC5843
#define HMC58X3_R_YM (5)    //!< Register address for YM.
#define HMC58X3_R_YL (6)    //!< Register address for YL.
#define HMC58X3_R_ZM (7)    //!< Register address for ZM.
#define HMC58X3_R_ZL (8)    //!< Register address for ZL.

#define HMC58X3_X_SELF_TEST_GAUSS (+0.55)                       //!< X axis level when bias current is applied.
#define HMC58X3_Y_SELF_TEST_GAUSS (HMC58X3_X_SELF_TEST_GAUSS)   //!< Y axis level when bias current is applied.
#define HMC58X3_Z_SELF_TEST_GAUSS (HMC58X3_X_SELF_TEST_GAUSS)   //!< Y axis level when bias current is applied.

/*
    This is my best guess at the LOW, HIGH limit.  The data sheet does not have these values.
*/
#define SELF_TEST_LOW_LIMIT  (HMC58X3_X_SELF_TEST_GAUSS*0.53)   //!< Low limit 53% of expected value.
#define SELF_TEST_HIGH_LIMIT (HMC58X3_X_SELF_TEST_GAUSS*1.36)   //!< High limit 136% of expected values.
#else // HMC5883L
#define HMC58X3_R_YM (7)  //!< Register address for YM.
#define HMC58X3_R_YL (8)  //!< Register address for YL.
#define HMC58X3_R_ZM (5)  //!< Register address for ZM.
#define HMC58X3_R_ZL (6)  //!< Register address for ZL.

#define HMC58X3_X_SELF_TEST_GAUSS (+1.16)                       //!< X axis level when bias current is applied.
#define HMC58X3_Y_SELF_TEST_GAUSS (HMC58X3_X_SELF_TEST_GAUSS)   //!< Y axis level when bias current is applied.
#define HMC58X3_Z_SELF_TEST_GAUSS (+1.08)                       //!< Y axis level when bias current is applied.

#define SELF_TEST_LOW_LIMIT  (243.0/390.0)   //!< Low limit when gain is 5.
#define SELF_TEST_HIGH_LIMIT (575.0/390.0)   //!< High limit when gain is 5.
#endif

#define HMC58X3_R_STATUS 9
//#define HMC58X3_R_IDA 10
#define HMC58X3_R_IDB 11
#define HMC58X3_R_IDC 12

class HMC58X3
{


public:
    HMC58X3();
    void init(bool setmode);
    void init(int address, bool setmode);
    void getValues(int16_t *x,int16_t *y,int16_t *z);
    void getValues(float *x,float *y,float *z);
    void getValues(float *xyz);
    void getRaw(int16_t *x,int16_t *y,int16_t *z);
    void getRaw(int16_t *xyz);
    void calibrate(unsigned char gain);     // Original calibrate with a few weaknesses.
    bool calibrate(unsigned char gain,unsigned int n_samples);
    void setMode(unsigned char mode);
    void setDOR(unsigned char DOR);
    void setGain(unsigned char gain);
    void getID(char id[3]);
    
    int16_t cache_x, cache_y, cache_z;
    
    static void samplingthread_stub(void const *p);
    
    void samplingthread();
    void start_sampling();

    static const int I2C_ADDRESS = 0x3D;
    char HMC58X3_R_IDA;
    MODI2C i2c;
    
    Thread _thread;
    
    Semaphore sem;

private:
    void writeReg(unsigned char reg, unsigned char val);
    float x_scale,y_scale,z_scale,x_max,y_max,z_max;
    int min(int a, int b);
};

#endif // HMC58X3_h