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
|
/* Copyright (c) 2010-2011 mbed.org, MIT License
*
* 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 "MMA8451Q.h"
#define REG_WHO_AM_I 0x0D
#define REG_CTRL_REG_1 0x2A
#define REG_OUT_X_MSB 0x01
#define REG_OUT_Y_MSB 0x03
#define REG_OUT_Z_MSB 0x05
#define UINT14_MAX 16383
MMA8451Q::MMA8451Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
// activate the peripheral
uint8_t data[2] = {REG_CTRL_REG_1, 0x01};
writeRegs(data, 2);
}
MMA8451Q::~MMA8451Q() { }
uint8_t MMA8451Q::getWhoAmI() {
uint8_t who_am_i = 0;
readRegs(REG_WHO_AM_I, &who_am_i, 1);
return who_am_i;
}
int16_t MMA8451Q::getAccX() {
return getAccAxis(REG_OUT_X_MSB);
}
int16_t MMA8451Q::getAccY() {
return getAccAxis(REG_OUT_Y_MSB);
}
int16_t MMA8451Q::getAccZ() {
return getAccAxis(REG_OUT_Z_MSB);
}
void MMA8451Q::getAccAllAxis(int16_t * res) {
res[0] = getAccX();
res[1] = getAccY();
res[2] = getAccZ();
}
int16_t MMA8451Q::getAccAxis(uint8_t addr) {
int16_t acc;
uint8_t res[2];
readRegs(addr, res, 2);
acc = (res[0] << 6) | (res[1] >> 2);
if (acc > UINT14_MAX/2)
acc -= UINT14_MAX;
return acc;
}
void MMA8451Q::readRegs(int addr, uint8_t * data, int len) {
char t[1] = {addr};
m_i2c.write(m_addr, t, 1, true);
m_i2c.read(m_addr, (char *)data, len);
}
void MMA8451Q::writeRegs(uint8_t * data, int len) {
m_i2c.write(m_addr, (char *)data, len);
}
|
