1 /*
2  * Author: Brendan Le Foll <brendan.le.foll@intel.com>
3  * Contributions: Mihai Tudor Panu <mihai.tudor.panu@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