summaryrefslogtreecommitdiffstats
path: root/watch-library/driver/lis2dh.c
blob: 20702bf55fc796c40b200b0eeb3ea62284684ba2 (plain)
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
/*
 * MIT License
 *
 * Copyright (c) 2021 Joey Castillo
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include "lis2dh.h"
#include "watch.h"

bool lis2dh_begin(void) {
    if (lis2dh_get_device_id() != LIS2DH_WHO_AM_I_VAL) {
        return false;
    }
    // Enable all axes, start at lowest possible data rate
    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL1, LIS2DH_CTRL1_VAL_XEN |
                                                       LIS2DH_CTRL1_VAL_YEN |
                                                       LIS2DH_CTRL1_VAL_ZEN |
                                                       LIS2DH_CTRL1_VAL_ODR_1HZ);
    // Set range to ±2G and enable block data update (output registers not updated until MSB and LSB have been read)
    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL4, LIS2DH_CTRL4_VAL_BDU | LIS2DH_RANGE_2_G);

    return true;
}

uint8_t lis2dh_get_device_id(void) {
    return watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_WHO_AM_I);
}

bool lis2dh_have_new_data(void) {
    uint8_t retval = watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_STATUS);
    return !!retval; // return true if any bit is set
}

lis2dh_reading lis2dh_get_raw_reading(void) {
    uint8_t buffer[6];
    uint8_t reg = LIS2DH_REG_OUT_X_L | 0x80; // set high bit for consecutive reads
    lis2dh_reading retval;

    watch_i2c_send(LIS2DH_ADDRESS, &reg, 1);
    watch_i2c_receive(LIS2DH_ADDRESS, (uint8_t *)&buffer, 6);

    retval.x = buffer[0];
    retval.x |= ((uint16_t)buffer[1]) << 8;
    retval.y = buffer[2];
    retval.y |= ((uint16_t)buffer[3]) << 8;
    retval.z = buffer[4];
    retval.z |= ((uint16_t)buffer[5]) << 8;

    return retval;
}

 lis2dh_acceleration_measurement lis2dh_get_acceleration_measurement(lis2dh_reading *out_reading) {
    lis2dh_reading reading = lis2dh_get_raw_reading();
    uint8_t range = lis2dh_get_range();
    if (out_reading != NULL) *out_reading = reading;

    // this bit is cribbed from Adafruit's LIS3DH driver; from their notes, the magic number below
    // converts from 16-bit lsb to 10-bit and divides by 1k to convert from milli-gs.
    // final value is raw_lsb => 10-bit lsb -> milli-gs -> gs
    uint8_t lsb_value = 1;
    if (range == LIS2DH_RANGE_2_G) lsb_value = 4;
    if (range == LIS2DH_RANGE_4_G) lsb_value = 8;
    if (range == LIS2DH_RANGE_8_G) lsb_value = 16;
    if (range == LIS2DH_RANGE_16_G) lsb_value = 48;

    lis2dh_acceleration_measurement retval;

    retval.x = lsb_value * ((float)reading.x / 64000.0);
    retval.y = lsb_value * ((float)reading.y / 64000.0);
    retval.z = lsb_value * ((float)reading.z / 64000.0);

    return retval;
}

void lis2dh_set_range(lis2dh_range_t range) {
    uint8_t val = watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL4) & 0xCF;
    uint8_t bits = range << 4;

    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL4, val | bits);
}

lis2dh_range_t lis2dh_get_range(void) {
    uint8_t retval = watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL4) & 0x30;
    retval >>= 4;
    return (lis2dh_range_t)retval;
}


void lis2dh_set_data_rate(lis2dh_data_rate_t dataRate) {
    uint8_t val = watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL1) & 0x0F;
    uint8_t bits = dataRate << 4;

    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL1, val | bits);
}

lis2dh_data_rate_t lis2dh_get_data_rate(void) {
    return watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL1) >> 4;
}

void lis2dh_configure_aoi_int1(lis2dh_interrupt_configuration configuration, uint8_t threshold, uint8_t duration, bool latch) {
    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL3, LIS2DH_CTRL3_VAL_I1_AOI1);
    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_INT1_CFG, configuration);
    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_INT1_THS, threshold);
    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_INT1_DUR, duration);
    uint8_t val = watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL5) & 0xF7;
    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL5, val | latch ? LIS2DH_CTRL5_VAL_LIR_INT1 : 0);
}

lis2dh_interrupt_state lis2dh_get_int1_state(void) {
    return (lis2dh_interrupt_state) watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_INT1_SRC);
}

void lis2dh_configure_aoi_int2(lis2dh_interrupt_configuration configuration, uint8_t threshold, uint8_t duration, bool latch) {
    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL6, LIS2DH_CTRL6_VAL_I2_INT2);
    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_INT2_CFG, configuration);
    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_INT2_THS, threshold);
    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_INT2_DUR, duration);
    uint8_t val = watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL5) & 0xFD;
    watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL5, val | latch ? LIS2DH_CTRL5_VAL_LIR_INT2 : 0);
}

lis2dh_interrupt_state lis2dh_get_int2_state(void) {
    return (lis2dh_interrupt_state) watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_INT2_SRC);
}