Stanley Cohen / MMA8451Q8_1

Allowed for the choosing the g-range of the accelerometer. Scaling also tracks choice so units and values are correct

Dependents:   LCD_punch_mtr_8_v5 LCD_punch_mtr_8_v5

Fork of MMA8451Q by Emilio Monti

MMA8451Q8.cpp@6:e0dc3cd59991, 2015-01-28 (annotated)

Committer:
scohennm
Date:
Wed Jan 28 20:42:56 2015 +0000
Revision:
6:e0dc3cd59991
Parent:
5:5a7293378401 
Integer counts add

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 5:5a7293378401 18 // Modify to change full scale gravity range 141207 sc
samux 1:d2630136d51e 19
scohennm 5:5a7293378401 20
scohennm 5:5a7293378401 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 5:5a7293378401 28 #define XYZ_DATA_CFG 0x0E
emilmont 0:6149091f755d 29
samux 1:d2630136d51e 30 #define UINT14_MAX 16383
emilmont 0:6149091f755d 31
scohennm 5:5a7293378401 32 #define MAX_2G 0x00
scohennm 5:5a7293378401 33 #define MAX_4G 0x01
scohennm 5:5a7293378401 34 #define MAX_8G 0x02
scohennm 5:5a7293378401 35
scohennm 5:5a7293378401 36 #define NUM_DATA 2
scohennm 5:5a7293378401 37 #define GSCALING 1024.0
scohennm 5:5a7293378401 38 #define ADDRESS_INDEX 0
scohennm 5:5a7293378401 39 #define DATA_INDEX 1
scohennm 5:5a7293378401 40
scohennm 5:5a7293378401 41 float gScaling[3] = {4095.0,2048.0,1024.0}; //scaling for acceleration of gravity values
scohennm 5:5a7293378401 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 }
scohennm 5:5a7293378401 56 void MMA8451Q::setGLimit(int gSelect) {
scohennm 5:5a7293378401 57 uint8_t data[NUM_DATA] = {REG_CTRL_REG_1, 0x00};
scohennm 5:5a7293378401 58 gChosen = gSelect;
scohennm 5:5a7293378401 59 writeRegs(data, NUM_DATA); // put in standby
scohennm 5:5a7293378401 60 data[ADDRESS_INDEX ] = XYZ_DATA_CFG;
scohennm 5:5a7293378401 61 data[DATA_INDEX] = gChosen;
scohennm 5:5a7293378401 62 writeRegs(data, 2);// change g limit
scohennm 5:5a7293378401 63 data[ADDRESS_INDEX ] = REG_CTRL_REG_1;
scohennm 5:5a7293378401 64 data[DATA_INDEX] = 0x01;
scohennm 5:5a7293378401 65 writeRegs(data, 2); // make active
scohennm 5:5a7293378401 66 }
emilmont 0:6149091f755d 67
chris 3:db7126dbd63f 68 float MMA8451Q::getAccX() {
scohennm 5:5a7293378401 69 return (float(getAccAxis(REG_OUT_X_MSB))/gScaling[gChosen]);
emilmont 0:6149091f755d 70 }
emilmont 0:6149091f755d 71
chris 3:db7126dbd63f 72 float MMA8451Q::getAccY() {
scohennm 5:5a7293378401 73 return (float(getAccAxis(REG_OUT_Y_MSB))/gScaling[gChosen]);
emilmont 0:6149091f755d 74 }
emilmont 0:6149091f755d 75
chris 3:db7126dbd63f 76 float MMA8451Q::getAccZ() {
scohennm 5:5a7293378401 77 return (float(getAccAxis(REG_OUT_Z_MSB))/gScaling[gChosen]);
emilmont 0:6149091f755d 78 }
emilmont 0:6149091f755d 79
chris 3:db7126dbd63f 80 void MMA8451Q::getAccAllAxis(float * res) {
emilmont 0:6149091f755d 81 res[0] = getAccX();
emilmont 0:6149091f755d 82 res[1] = getAccY();
emilmont 0:6149091f755d 83 res[2] = getAccZ();
emilmont 0:6149091f755d 84 }
emilmont 0:6149091f755d 85
emilmont 0:6149091f755d 86 int16_t MMA8451Q::getAccAxis(uint8_t addr) {
emilmont 0:6149091f755d 87 int16_t acc;
emilmont 0:6149091f755d 88 uint8_t res[2];
samux 1:d2630136d51e 89 readRegs(addr, res, 2);
emilmont 0:6149091f755d 90
emilmont 0:6149091f755d 91 acc = (res[0] << 6) | (res[1] >> 2);
emilmont 0:6149091f755d 92 if (acc > UINT14_MAX/2)
emilmont 0:6149091f755d 93 acc -= UINT14_MAX;
emilmont 0:6149091f755d 94
emilmont 0:6149091f755d 95 return acc;
emilmont 0:6149091f755d 96 }
emilmont 0:6149091f755d 97
samux 1:d2630136d51e 98 void MMA8451Q::readRegs(int addr, uint8_t * data, int len) {
emilmont 0:6149091f755d 99 char t[1] = {addr};
emilmont 0:6149091f755d 100 m_i2c.write(m_addr, t, 1, true);
emilmont 0:6149091f755d 101 m_i2c.read(m_addr, (char *)data, len);
emilmont 0:6149091f755d 102 }
emilmont 0:6149091f755d 103
samux 1:d2630136d51e 104 void MMA8451Q::writeRegs(uint8_t * data, int len) {
emilmont 0:6149091f755d 105 m_i2c.write(m_addr, (char *)data, len);
emilmont 0:6149091f755d 106 }