David McDaid / MMA8451Q

My version of the library for this accelerometer. It works on 800Hz data rate.

Dependents:   FRDM_DEMO_CODE

Fork of MMA8451Q by Antonio Quevedo

MMA8451Q.cpp@1:204db61f9c8f, 2014-08-19 (annotated)

Committer:
B50132
Date:
Tue Aug 19 15:05:55 2014 +0000
Revision:
1:204db61f9c8f
Parent:
0:7c9ab58f6af3 
modified contents with another library doing the same thing.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
quevedo 0:7c9ab58f6af3 1 /* Copyright (c) 2010-2011 mbed.org, MIT License
quevedo 0:7c9ab58f6af3 2 *
quevedo 0:7c9ab58f6af3 3 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
quevedo 0:7c9ab58f6af3 4 * and associated documentation files (the "Software"), to deal in the Software without
quevedo 0:7c9ab58f6af3 5 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
quevedo 0:7c9ab58f6af3 6 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
quevedo 0:7c9ab58f6af3 7 * Software is furnished to do so, subject to the following conditions:
quevedo 0:7c9ab58f6af3 8 *
quevedo 0:7c9ab58f6af3 9 * The above copyright notice and this permission notice shall be included in all copies or
quevedo 0:7c9ab58f6af3 10 * substantial portions of the Software.
quevedo 0:7c9ab58f6af3 11 *
quevedo 0:7c9ab58f6af3 12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
quevedo 0:7c9ab58f6af3 13 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
quevedo 0:7c9ab58f6af3 14 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
quevedo 0:7c9ab58f6af3 15 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
quevedo 0:7c9ab58f6af3 16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
quevedo 0:7c9ab58f6af3 17 */
quevedo 0:7c9ab58f6af3 18
quevedo 0:7c9ab58f6af3 19 #include "MMA8451Q.h"
quevedo 0:7c9ab58f6af3 20
quevedo 0:7c9ab58f6af3 21 #define REG_WHO_AM_I 0x0D
B50132 1:204db61f9c8f 22 #define REG_CTRL_REG_1 0x2A
quevedo 0:7c9ab58f6af3 23 #define REG_OUT_X_MSB 0x01
quevedo 0:7c9ab58f6af3 24 #define REG_OUT_Y_MSB 0x03
quevedo 0:7c9ab58f6af3 25 #define REG_OUT_Z_MSB 0x05
quevedo 0:7c9ab58f6af3 26
B50132 1:204db61f9c8f 27 #define UINT14_MAX 16383
B50132 1:204db61f9c8f 28
B50132 1:204db61f9c8f 29 MMA8451Q::MMA8451Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
B50132 1:204db61f9c8f 30 // activate the peripheral
B50132 1:204db61f9c8f 31 uint8_t data[2] = {REG_CTRL_REG_1, 0x01};
quevedo 0:7c9ab58f6af3 32 writeRegs(data, 2);
quevedo 0:7c9ab58f6af3 33 }
quevedo 0:7c9ab58f6af3 34
quevedo 0:7c9ab58f6af3 35 MMA8451Q::~MMA8451Q() { }
quevedo 0:7c9ab58f6af3 36
B50132 1:204db61f9c8f 37 uint8_t MMA8451Q::getWhoAmI() {
B50132 1:204db61f9c8f 38 uint8_t who_am_i = 0;
B50132 1:204db61f9c8f 39 readRegs(REG_WHO_AM_I, &who_am_i, 1);
B50132 1:204db61f9c8f 40 return who_am_i;
B50132 1:204db61f9c8f 41 }
B50132 1:204db61f9c8f 42
B50132 1:204db61f9c8f 43 float MMA8451Q::getAccX() {
B50132 1:204db61f9c8f 44 return (float(getAccAxis(REG_OUT_X_MSB))/4096.0);
B50132 1:204db61f9c8f 45 }
B50132 1:204db61f9c8f 46
B50132 1:204db61f9c8f 47 float MMA8451Q::getAccY() {
B50132 1:204db61f9c8f 48 return (float(getAccAxis(REG_OUT_Y_MSB))/4096.0);
B50132 1:204db61f9c8f 49 }
B50132 1:204db61f9c8f 50
B50132 1:204db61f9c8f 51 float MMA8451Q::getAccZ() {
B50132 1:204db61f9c8f 52 return (float(getAccAxis(REG_OUT_Z_MSB))/4096.0);
B50132 1:204db61f9c8f 53 }
B50132 1:204db61f9c8f 54
B50132 1:204db61f9c8f 55 void MMA8451Q::getAccAllAxis(float * res) {
B50132 1:204db61f9c8f 56 res[0] = getAccX();
B50132 1:204db61f9c8f 57 res[1] = getAccY();
B50132 1:204db61f9c8f 58 res[2] = getAccZ();
B50132 1:204db61f9c8f 59 }
B50132 1:204db61f9c8f 60
B50132 1:204db61f9c8f 61 int16_t MMA8451Q::getAccAxis(uint8_t addr) {
B50132 1:204db61f9c8f 62 int16_t acc;
B50132 1:204db61f9c8f 63 uint8_t res[2];
B50132 1:204db61f9c8f 64 readRegs(addr, res, 2);
B50132 1:204db61f9c8f 65
B50132 1:204db61f9c8f 66 acc = (res[0] << 6) | (res[1] >> 2);
B50132 1:204db61f9c8f 67 if (acc > UINT14_MAX/2)
B50132 1:204db61f9c8f 68 acc -= UINT14_MAX;
B50132 1:204db61f9c8f 69
B50132 1:204db61f9c8f 70 return acc;
quevedo 0:7c9ab58f6af3 71 }
quevedo 0:7c9ab58f6af3 72
quevedo 0:7c9ab58f6af3 73 void MMA8451Q::readRegs(int addr, uint8_t * data, int len) {
quevedo 0:7c9ab58f6af3 74 char t[1] = {addr};
B50132 1:204db61f9c8f 75 m_i2c.write(m_addr, t, 1, true);
B50132 1:204db61f9c8f 76 m_i2c.read(m_addr, (char *)data, len);
quevedo 0:7c9ab58f6af3 77 }
quevedo 0:7c9ab58f6af3 78
quevedo 0:7c9ab58f6af3 79 void MMA8451Q::writeRegs(uint8_t * data, int len) {
B50132 1:204db61f9c8f 80 m_i2c.write(m_addr, (char *)data, len);
B50132 1:204db61f9c8f 81 }