Mark Turner / MMA8451Q8

thisone

Dependents:   LCD_ACC_46_v4-8g

Fork of MMA8451Q8 by Stanley Cohen

MMA8451Q8.cpp@9:79ca3a3ce1e7, 2017-03-08 (annotated)

Committer:
mturner5
Date:
Wed Mar 08 06:23:19 2017 +0000
Revision:
9:79ca3a3ce1e7
Parent:
8:e7197838ba82 
revision;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
samux 1:d2630136d51e 1 /* Copyright (c) 2010-2011 mbed.org, MIT License
samux 1:d2630136d51e 2 *
samux 1:d2630136d51e 3 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
samux 1:d2630136d51e 4 * and associated documentation files (the "Software"), to deal in the Software without
samux 1:d2630136d51e 5 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
samux 1:d2630136d51e 6 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
samux 1:d2630136d51e 7 * Software is furnished to do so, subject to the following conditions:
samux 1:d2630136d51e 8 *
samux 1:d2630136d51e 9 * The above copyright notice and this permission notice shall be included in all copies or
samux 1:d2630136d51e 10 * substantial portions of the Software.
samux 1:d2630136d51e 11 *
samux 1:d2630136d51e 12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
samux 1:d2630136d51e 13 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
samux 1:d2630136d51e 14 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
samux 1:d2630136d51e 15 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
samux 1:d2630136d51e 16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
samux 1:d2630136d51e 17 */
scohennm 5:be042e8c1756 18 // Modify to change full scale gravity range 141207 sc
samux 1:d2630136d51e 19
scohennm 5:be042e8c1756 20
scohennm 5:be042e8c1756 21 #include "MMA8451Q8.h"
emilmont 0:6149091f755d 22
samux 1:d2630136d51e 23 #define REG_WHO_AM_I 0x0D
samux 1:d2630136d51e 24 #define REG_CTRL_REG_1 0x2A
emilmont 0:6149091f755d 25 #define REG_OUT_X_MSB 0x01
emilmont 0:6149091f755d 26 #define REG_OUT_Y_MSB 0x03
emilmont 0:6149091f755d 27 #define REG_OUT_Z_MSB 0x05
scohennm 5:be042e8c1756 28 #define XYZ_DATA_CFG 0x0E
emilmont 0:6149091f755d 29
samux 1:d2630136d51e 30 #define UINT14_MAX 16383
emilmont 0:6149091f755d 31
scohennm 5:be042e8c1756 32 #define MAX_2G 0x00
scohennm 5:be042e8c1756 33 #define MAX_4G 0x01
scohennm 6:c29386367dcf 34 #define MAX_8G 0x02
scohennm 5:be042e8c1756 35
mturner5 9:79ca3a3ce1e7 36 #define NUM_DATA 2
scohennm 5:be042e8c1756 37 #define GSCALING 1024.0
mturner5 9:79ca3a3ce1e7 38 #define ADRESS_INDEX 0
mturner5 9:79ca3a3ce1e7 39 #define DATA_INDEX 1
scohennm 5:be042e8c1756 40
mturner5 8:e7197838ba82 41 float gScaling[3] = {4095.0,2048.0,1024.0}; //scaling for acceleration?
mturner5 8:e7197838ba82 42
emilmont 0:6149091f755d 43 MMA8451Q::MMA8451Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
emilmont 0:6149091f755d 44 // activate the peripheral
emilmont 0:6149091f755d 45 uint8_t data[2] = {REG_CTRL_REG_1, 0x01};
samux 1:d2630136d51e 46 writeRegs(data, 2);
emilmont 0:6149091f755d 47 }
emilmont 0:6149091f755d 48
emilmont 0:6149091f755d 49 MMA8451Q::~MMA8451Q() { }
emilmont 0:6149091f755d 50
emilmont 0:6149091f755d 51 uint8_t MMA8451Q::getWhoAmI() {
emilmont 0:6149091f755d 52 uint8_t who_am_i = 0;
samux 1:d2630136d51e 53 readRegs(REG_WHO_AM_I, &who_am_i, 1);
emilmont 0:6149091f755d 54 return who_am_i;
emilmont 0:6149091f755d 55 }
mturner5 9:79ca3a3ce1e7 56
mturner5 9:79ca3a3ce1e7 57 void MMA8451Q::setStandbyMode() {
mturner5 9:79ca3a3ce1e7 58 #define ACTIVEMASK 0X01
mturner5 9:79ca3a3ce1e7 59 uint8_t registerData[1];
mturner5 9:79ca3a3ce1e7 60 uint8_t data[NUM_DATA] = {REG_CTRL_REG_1, 0x00};
mturner5 9:79ca3a3ce1e7 61
mturner5 9:79ca3a3ce1e7 62 readRegs(REG_CTRL_REG_1, registerData, 1);
mturner5 9:79ca3a3ce1e7 63 data[1] = registerData[0] & ~ACTIVEMASK; // ~ flips the ACTIVEMASK, so 000000001 becomes 11111110
mturner5 9:79ca3a3ce1e7 64 writeRegs(data, NUM_DATA); //standby
mturner5 9:79ca3a3ce1e7 65 }
mturner5 9:79ca3a3ce1e7 66
mturner5 9:79ca3a3ce1e7 67 void MMA8451Q::setActiveMode() {
mturner5 9:79ca3a3ce1e7 68 #define ACTIVEMASK 0X01
mturner5 9:79ca3a3ce1e7 69 uint8_t registerData[1];
mturner5 9:79ca3a3ce1e7 70 uint8_t data[NUM_DATA] = {REG_CTRL_REG_1, 0x00};
mturner5 9:79ca3a3ce1e7 71
mturner5 9:79ca3a3ce1e7 72 readRegs(REG_CTRL_REG_1, registerData, 1);
mturner5 9:79ca3a3ce1e7 73 data[1] = registerData[0] | ~ACTIVEMASK;
mturner5 9:79ca3a3ce1e7 74 writeRegs(data, NUM_DATA);
mturner5 9:79ca3a3ce1e7 75 }
mturner5 9:79ca3a3ce1e7 76
mturner5 8:e7197838ba82 77 void MMA8451Q::setGLimit(int gSelect) {
mturner5 8:e7197838ba82 78 uint8_t data[NUM_DATA] = {REG_CTRL_REG_1, 0x00};
mturner5 8:e7197838ba82 79 gChosen = gSelect;
mturner5 9:79ca3a3ce1e7 80 setStandbyMode();
mturner5 8:e7197838ba82 81 data[ADRESS_INDEX ] = XYZ_DATA_CFG;
mturner5 8:e7197838ba82 82 data[DATA_INDEX] = gChosen;
scohennm 5:be042e8c1756 83 writeRegs(data, 2);// change g limit
mturner5 9:79ca3a3ce1e7 84 setActiveMode(); //make active
scohennm 5:be042e8c1756 85 }
emilmont 0:6149091f755d 86
chris 3:db7126dbd63f 87 float MMA8451Q::getAccX() {
mturner5 9:79ca3a3ce1e7 88 return (float(getAccAxis(REG_OUT_X_MSB))/gScaling[gChosen]);
emilmont 0:6149091f755d 89 }
emilmont 0:6149091f755d 90
chris 3:db7126dbd63f 91 float MMA8451Q::getAccY() {
mturner5 9:79ca3a3ce1e7 92 return (float(getAccAxis(REG_OUT_Y_MSB))/gScaling[gChosen]);
emilmont 0:6149091f755d 93 }
emilmont 0:6149091f755d 94
chris 3:db7126dbd63f 95 float MMA8451Q::getAccZ() {
mturner5 9:79ca3a3ce1e7 96 return (float(getAccAxis(REG_OUT_Z_MSB))/gScaling[gChosen]);
emilmont 0:6149091f755d 97 }
emilmont 0:6149091f755d 98
chris 3:db7126dbd63f 99 void MMA8451Q::getAccAllAxis(float * res) {
emilmont 0:6149091f755d 100 res[0] = getAccX();
emilmont 0:6149091f755d 101 res[1] = getAccY();
emilmont 0:6149091f755d 102 res[2] = getAccZ();
emilmont 0:6149091f755d 103 }
emilmont 0:6149091f755d 104
emilmont 0:6149091f755d 105 int16_t MMA8451Q::getAccAxis(uint8_t addr) {
emilmont 0:6149091f755d 106 int16_t acc;
emilmont 0:6149091f755d 107 uint8_t res[2];
samux 1:d2630136d51e 108 readRegs(addr, res, 2);
emilmont 0:6149091f755d 109
emilmont 0:6149091f755d 110 acc = (res[0] << 6) | (res[1] >> 2);
emilmont 0:6149091f755d 111 if (acc > UINT14_MAX/2)
emilmont 0:6149091f755d 112 acc -= UINT14_MAX;
emilmont 0:6149091f755d 113
emilmont 0:6149091f755d 114 return acc;
emilmont 0:6149091f755d 115 }
emilmont 0:6149091f755d 116
samux 1:d2630136d51e 117 void MMA8451Q::readRegs(int addr, uint8_t * data, int len) {
emilmont 0:6149091f755d 118 char t[1] = {addr};
emilmont 0:6149091f755d 119 m_i2c.write(m_addr, t, 1, true);
emilmont 0:6149091f755d 120 m_i2c.read(m_addr, (char *)data, len);
emilmont 0:6149091f755d 121 }
emilmont 0:6149091f755d 122
samux 1:d2630136d51e 123 void MMA8451Q::writeRegs(uint8_t * data, int len) {
emilmont 0:6149091f755d 124 m_i2c.write(m_addr, (char *)data, len);
emilmont 0:6149091f755d 125 }