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      1 /*
      2  * Author: Brendan Le Foll <brendan.le.foll (at) intel.com>
      3  * Contributions: Mihai Tudor Panu <mihai.tudor.panu (at) intel.com>
      4  * Copyright (c) 2014 Intel Corporation.
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining
      7  * a copy of this software and associated documentation files (the
      8  * "Software"), to deal in the Software without restriction, including
      9  * without limitation the rights to use, copy, modify, merge, publish,
     10  * distribute, sublicense, and/or sell copies of the Software, and to
     11  * permit persons to whom the Software is furnished to do so, subject to
     12  * the following conditions:
     13  *
     14  * The above copyright notice and this permission notice shall be
     15  * included in all copies or substantial portions of the Software.
     16  *
     17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     20  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
     21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
     22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
     23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     24  */
     25 #pragma once
     26 
     27 #include <mraa/i2c.hpp>
     28 
     29 #define MAX_BUFFER_LENGTH 6
     30 
     31 namespace upm {
     32 
     33 /**
     34  * @brief HMC5883L Magnometer library
     35  * @defgroup hmc5883l libupm-hmc5883l
     36  * @ingroup seeed i2c compass robok
     37  */
     38 
     39 /**
     40  * @library hmc5883l
     41  * @sensor hmc5883l
     42  * @comname HMC5883L 3-Axis Digital Compass
     43  * @altname Grove 3-Axis Digital Compass
     44  * @type compass
     45  * @man seeed
     46  * @con i2c
     47  * @kit robok
     48  *
     49  * @brief API for the HMC5883L 3-Axis Digital Compass
     50  *
     51  * Honeywell [HMC5883L]
     52  * (http://www.adafruit.com/datasheets/HMC5883L_3-Axis_Digital_Compass_IC.pdf)
     53  * is a 3-axis digital compass. Communication with HMC5883L is simple and
     54  * all done through an I2C interface. Different breakout boards are available.
     55  * Typically, a 3V supply is all that is needed to power the sensor.
     56  *
     57  * @image html hmc5883l.jpeg
     58  * @snippet hmc5883l.cxx Interesting
     59  */
     60 class Hmc5883l {
     61 public:
     62     /**
     63      * Creates an Hmc5883l object
     64      *
     65      * @param bus Number of the used I2C bus
     66      */
     67     Hmc5883l(int bus);
     68 
     69     /*
     70      * Returns the direction
     71      */
     72     float direction();
     73 
     74     /*
     75      * Returns the heading
     76      */
     77     float heading();
     78 
     79     /**
     80      * Returns a pointer to an int[3] that contains the coordinates as ints
     81      *
     82      * @return *int to an int[3]
     83      */
     84     int16_t* coordinates();
     85 
     86     /**
     87      * Updates the values by reading from I2C
     88      *
     89      * @return 0 if successful
     90      */
     91     mraa::Result update();
     92 
     93     /**
     94      * Sets the magnetic declination for better calibration
     95      */
     96     void set_declination(float dec);
     97 
     98     /**
     99      * Gets the current magnetic declination value
    100      *
    101      * @return Magnetic declination as a floating-point value
    102      */
    103     float get_declination();
    104 private:
    105     int16_t m_coor[3];
    106     float m_declination;
    107     uint8_t m_rx_tx_buf[MAX_BUFFER_LENGTH];
    108     mraa::I2c m_i2c;
    109 };
    110 
    111 }
    112