Emilio Monti / MMA8451Q

samux MMA8451Q accelerometer library

Dependents:   AirMouse FRDM_LCD4884 TextLCD_HelloWorld FRDM_MMA8451Q ... more

MMA8451Q.cpp@4:c4d879a39775, 2012-10-12 (annotated)

Committer:
chris
Date:
Fri Oct 12 11:35:07 2012 +0000
Revision:
4:c4d879a39775
Parent:
3:db7126dbd63f 
Pushed objec declaration into main

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 */
samux 1:d2630136d51e 18
emilmont 0:6149091f755d 19 #include "MMA8451Q.h"
emilmont 0:6149091f755d 20
samux 1:d2630136d51e 21 #define REG_WHO_AM_I 0x0D
samux 1:d2630136d51e 22 #define REG_CTRL_REG_1 0x2A
emilmont 0:6149091f755d 23 #define REG_OUT_X_MSB 0x01
emilmont 0:6149091f755d 24 #define REG_OUT_Y_MSB 0x03
emilmont 0:6149091f755d 25 #define REG_OUT_Z_MSB 0x05
emilmont 0:6149091f755d 26
samux 1:d2630136d51e 27 #define UINT14_MAX 16383
emilmont 0:6149091f755d 28
emilmont 0:6149091f755d 29 MMA8451Q::MMA8451Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
emilmont 0:6149091f755d 30 // activate the peripheral
emilmont 0:6149091f755d 31 uint8_t data[2] = {REG_CTRL_REG_1, 0x01};
samux 1:d2630136d51e 32 writeRegs(data, 2);
emilmont 0:6149091f755d 33 }
emilmont 0:6149091f755d 34
emilmont 0:6149091f755d 35 MMA8451Q::~MMA8451Q() { }
emilmont 0:6149091f755d 36
emilmont 0:6149091f755d 37 uint8_t MMA8451Q::getWhoAmI() {
emilmont 0:6149091f755d 38 uint8_t who_am_i = 0;
samux 1:d2630136d51e 39 readRegs(REG_WHO_AM_I, &who_am_i, 1);
emilmont 0:6149091f755d 40 return who_am_i;
emilmont 0:6149091f755d 41 }
emilmont 0:6149091f755d 42
chris 3:db7126dbd63f 43 float MMA8451Q::getAccX() {
chris 3:db7126dbd63f 44 return (float(getAccAxis(REG_OUT_X_MSB))/4096.0);
emilmont 0:6149091f755d 45 }
emilmont 0:6149091f755d 46
chris 3:db7126dbd63f 47 float MMA8451Q::getAccY() {
chris 3:db7126dbd63f 48 return (float(getAccAxis(REG_OUT_Y_MSB))/4096.0);
emilmont 0:6149091f755d 49 }
emilmont 0:6149091f755d 50
chris 3:db7126dbd63f 51 float MMA8451Q::getAccZ() {
chris 3:db7126dbd63f 52 return (float(getAccAxis(REG_OUT_Z_MSB))/4096.0);
emilmont 0:6149091f755d 53 }
emilmont 0:6149091f755d 54
chris 3:db7126dbd63f 55 void MMA8451Q::getAccAllAxis(float * res) {
emilmont 0:6149091f755d 56 res[0] = getAccX();
emilmont 0:6149091f755d 57 res[1] = getAccY();
emilmont 0:6149091f755d 58 res[2] = getAccZ();
emilmont 0:6149091f755d 59 }
emilmont 0:6149091f755d 60
emilmont 0:6149091f755d 61 int16_t MMA8451Q::getAccAxis(uint8_t addr) {
emilmont 0:6149091f755d 62 int16_t acc;
emilmont 0:6149091f755d 63 uint8_t res[2];
samux 1:d2630136d51e 64 readRegs(addr, res, 2);
emilmont 0:6149091f755d 65
emilmont 0:6149091f755d 66 acc = (res[0] << 6) | (res[1] >> 2);
emilmont 0:6149091f755d 67 if (acc > UINT14_MAX/2)
emilmont 0:6149091f755d 68 acc -= UINT14_MAX;
emilmont 0:6149091f755d 69
emilmont 0:6149091f755d 70 return acc;
emilmont 0:6149091f755d 71 }
emilmont 0:6149091f755d 72
samux 1:d2630136d51e 73 void MMA8451Q::readRegs(int addr, uint8_t * data, int len) {
emilmont 0:6149091f755d 74 char t[1] = {addr};
emilmont 0:6149091f755d 75 m_i2c.write(m_addr, t, 1, true);
emilmont 0:6149091f755d 76 m_i2c.read(m_addr, (char *)data, len);
emilmont 0:6149091f755d 77 }
emilmont 0:6149091f755d 78
samux 1:d2630136d51e 79 void MMA8451Q::writeRegs(uint8_t * data, int len) {
emilmont 0:6149091f755d 80 m_i2c.write(m_addr, (char *)data, len);
emilmont 0:6149091f755d 81 }