A basic library for the FXOS8700Q combination accelerometer / magnetometer

Dependencies:   MotionSensor

Dependents:   K64F_eCompass_LCD Hello_FXOS8700Q rtos_compass K64F_eCompass ... more

This library supports the 6 axis combination Accelerometer / Magnetometer. Functions are provided to retrieve data in raw 16 bit signed integers or unit converted G's and micro-teslas

FXOS8700Q.cpp

Committer:
JimCarver
Date:
2014-04-23
Revision:
5:c4176a12f7d5
Parent:
4:be6abf9f2d59
Child:
6:cdc362f08339

File content as of revision 5:c4176a12f7d5:

/* 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 "FXOS8700Q.h"
#define UINT14_MAX        16383


FXOS8700Q_acc::FXOS8700Q_acc(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
    // activate the peripheral
    uint8_t data[2] = {FXOS8700Q_CTRL_REG1, 0x00};
    m_i2c.frequency(400000);
    writeRegs(data, 2);
    data[0] = FXOS8700Q_M_CTRL_REG1;
    data[1] = 0x1F;
    writeRegs(data, 2);
    data[0] = FXOS8700Q_M_CTRL_REG2;
    data[1] = 0x20;
    writeRegs(data, 2);
    data[0] = FXOS8700Q_XYZ_DATA_CFG;
    data[1] = 0x00;
    writeRegs(data, 2);
    data[0] = FXOS8700Q_CTRL_REG1;
    data[1] = 0x19;//0x1D;
    writeRegs(data, 2);
}


FXOS8700Q_acc::~FXOS8700Q_acc() { }

uint8_t FXOS8700Q_acc::getWhoAmI() {
    uint8_t who_am_i = 0;
    readRegs(FXOS8700Q_WHOAMI, &who_am_i, 1);
    return who_am_i;
}

float FXOS8700Q_acc::getAccX() {
    return (float(getAccAxis(FXOS8700Q_OUT_X_MSB))/4096.0);
}

float FXOS8700Q_acc::getAccY() {
    return (float(getAccAxis(FXOS8700Q_OUT_Y_MSB))/4096.0);
}

float FXOS8700Q_acc::getAccZ() {
    return (float(getAccAxis(FXOS8700Q_OUT_Z_MSB))/4096.0);
}


void FXOS8700Q_acc::getAxis(MotionSensorDataUnits * data) {
    data->x = getAccX();
    data->y = getAccY();
    data->z = getAccZ();
}

void FXOS8700Q_acc::getAxis(MotionSensorDataCounts * data {
    int16_t acc;
    uint8_t res[6];
    readRegs(FXOS8700Q_OUT_X_MSB, res, 6);

    acc = (res[0] << 6) | (res[1] >> 2);
    if (acc > UINT14_MAX/2)
        acc -= UINT14_MAX;
    data->x = acc;
    acc = (res[2] << 6) | (res[3] >> 2);
    if (acc > UINT14_MAX/2)
        acc -= UINT14_MAX;
    data->y = acc;
    acc = (res[4] << 6) | (res[5] >> 2);
    if (acc > UINT14_MAX/2)
        acc -= UINT14_MAX;
    data->z = acc;
}

void FXOS8700Q_acc::MagXYZraw(int16_t * d) {
    int16_t acc;
    uint8_t res[6];
    readRegs(FXOS8700Q_M_OUT_X_MSB, res, 6);

    d[0] = (res[0] << 8) | res[1];
    d[1] = (res[2] << 8) | res[3]; 
    d[2] = (res[4] << 8) | res[5];
}

void FXOS8700Q_acc::getMagAllAxis(float * res) {
    int16_t raw[3];
    MagXYZraw( raw);
    res[0] = (float) raw[0] * 0.1f;
    res[1] = (float) raw[1] * 0.1f;
    res[2] = (float) raw[2] * 0.1f;
}        
    
int16_t FXOS8700Q_acc::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 FXOS8700Q_acc::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 FXOS8700Q_acc::writeRegs(uint8_t * data, int len) {
    m_i2c.write(m_addr, (char *)data, len);
}