lis3mdl.c
4.17 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
/*
* Copyright (C) 2015 HAW Hamburg
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup drivers_lis3mdl
* @{
*
* @file
* @brief Device driver implementation for the LIS3MDL 3-axis magnetometer
*
* @author René Herthel <rene-herthel@outlook.de>
*
* @}
*/
#include "lis3mdl.h"
#include "include/lis3mdl-internal.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
#define MASK_INT16_MSB (0x8000)
#define MASK_INT16_NMSB (0x7FFF)
#define TEMP_DIVIDER (16)
#define TEMP_OFFSET (25)
#define GAUSS_DIVIDER (1000)
/**
* @brief Takes an unsigned value representing a two's complement number
* and returns the signed number it represents
*
* @param[in] value value which represents a two's complement number
*
* @return the converted signed number of 'value'
*/
static inline int16_t _twos_complement(int16_t value)
{
if (value & MASK_INT16_MSB) {
value = ~(value & MASK_INT16_NMSB) + 1;
return ~(value & MASK_INT16_NMSB);
}
else {
return value;
}
}
int lis3mdl_init(lis3mdl_t *dev,
i2c_t i2c,
uint8_t address,
lis3mdl_xy_mode_t xy_mode,
lis3mdl_z_mode_t z_mode,
lis3mdl_odr_t odr,
lis3mdl_scale_t scale,
lis3mdl_op_t op_mode) {
uint8_t tmp;
dev->i2c = i2c;
dev->addr = address;
i2c_acquire(dev->i2c);
if (i2c_init_master(i2c, I2C_SPEED_NORMAL) < 0) {
DEBUG("LIS3MDL: Master initialization failed\n");
return -1;
}
i2c_read_reg(dev->i2c, dev->addr, LIS3DML_WHO_AM_I_REG, &tmp);
if (tmp != LIS3MDL_CHIP_ID) {
DEBUG("LIS3MDL: Identification failed\n");
return -1;
}
tmp = ( LIS3MDL_MASK_REG1_TEMP_EN /* enable temperature sensor */
| xy_mode /* set x-, y-axis operative mode */
| odr); /* set output data rate */
i2c_write_reg(dev->i2c, dev->addr, LIS3MDL_CTRL_REG1, tmp);
/* set Full-scale configuration */
i2c_write_reg(dev->i2c, dev->addr, LIS3MDL_CTRL_REG2, scale);
/* set continuous-conversion mode */
i2c_write_reg(dev->i2c, dev->addr, LIS3MDL_CTRL_REG3, op_mode);
/* set z-axis operative mode */
i2c_write_reg(dev->i2c, dev->addr, LIS3MDL_CTRL_REG4, z_mode);
i2c_release(dev->i2c);
return 0;
}
void lis3mdl_read_mag(const lis3mdl_t *dev, lis3mdl_3d_data_t *data)
{
uint8_t tmp[2] = {0, 0};
i2c_acquire(dev->i2c);
i2c_read_regs(dev->i2c, dev->addr, LIS3MDL_OUT_X_L_REG, &tmp[0], 2);
data->x_axis = (tmp[1] << 8) | tmp[0];
i2c_read_regs(dev->i2c, dev->addr, LIS3MDL_OUT_Y_L_REG, &tmp[0], 2);
data->y_axis = (tmp[1] << 8) | tmp[0];
i2c_read_regs(dev->i2c, dev->addr, LIS3MDL_OUT_Z_L_REG, &tmp[0], 2);
data->z_axis = (tmp[1] << 8) | tmp[0];
data->x_axis = _twos_complement(data->x_axis);
data->y_axis = _twos_complement(data->y_axis);
data->z_axis = _twos_complement(data->z_axis);
/* Divide the raw data by 1000 to geht [G] := Gauss */
data->x_axis /= GAUSS_DIVIDER;
data->y_axis /= GAUSS_DIVIDER;
data->z_axis /= GAUSS_DIVIDER;
i2c_release(dev->i2c);
}
void lis3mdl_read_temp(const lis3mdl_t *dev, int16_t *value)
{
i2c_acquire(dev->i2c);
i2c_read_regs(dev->i2c, dev->addr, LIS3MDL_TEMP_OUT_L_REG, (uint8_t*)value, 2);
i2c_release(dev->i2c);
*value = _twos_complement(*value);
*value = (TEMP_OFFSET + (*value / TEMP_DIVIDER));
}
void lis3mdl_enable(const lis3mdl_t *dev)
{
i2c_acquire(dev->i2c);
/* Z-axis medium-power mode */
i2c_write_reg(dev->i2c, dev->addr,
LIS3MDL_CTRL_REG3, LIS3MDL_MASK_REG3_Z_MEDIUM_POWER);
i2c_release(dev->i2c);
}
void lis3mdl_disable(const lis3mdl_t *dev)
{
uint8_t tmp = ( LIS3MDL_MASK_REG3_LOW_POWER_EN /**< enable power-down mode */
| LIS3MDL_MASK_REG3_Z_LOW_POWER); /**< Z-axis low-power mode */
i2c_acquire(dev->i2c);
i2c_write_reg(dev->i2c, dev->addr, LIS3MDL_CTRL_REG3, tmp);
i2c_release(dev->i2c);
}