A basic library for the FXOS8700Q combination accelerometer / magnetometer

Dependencies:   MotionSensor

Fork of FXOS8700Q by Jim Carver

FXOS8700Q.cpp

Committer:
JimCarver
Date:
2014-04-13
Revision:
1:8b53edef272f
Parent:
0:2562215f5bc0
Child:
2:ab84f99086e5
Child:
3:eb1271ef90bc

File content as of revision 1:8b53edef272f:

#include "FXOS8700Q.h"
#define UINT14_MAX        16383


FXOS8700Q::FXOS8700Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
    // activate the peripheral
    uint8_t data[2] = {FXOS8700Q_CTRL_REG1, 0x00};
    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::~FXOS8700Q() { }

uint8_t FXOS8700Q::getWhoAmI() {
    uint8_t who_am_i = 0;
    readRegs(FXOS8700Q_WHOAMI, &who_am_i, 1);
    return who_am_i;
}

float FXOS8700Q::getAccX() {
    return (float(getAccAxis(FXOS8700Q_OUT_X_MSB))/4096.0);
}

float FXOS8700Q::getAccY() {
    return (float(getAccAxis(FXOS8700Q_OUT_Y_MSB))/4096.0);
}

float FXOS8700Q::getAccZ() {
    return (float(getAccAxis(FXOS8700Q_OUT_Z_MSB))/4096.0);
}


void FXOS8700Q::getAccAllAxis(float * res) {
    res[0] = getAccX();
    res[1] = getAccY();
    res[2] = getAccZ();
}

void FXOS8700Q::AccXYZraw(int16_t * d) {
    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;
    d[0] = acc;
    acc = (res[2] << 6) | (res[3] >> 2);
    if (acc > UINT14_MAX/2)
        acc -= UINT14_MAX;
    d[1] = acc;
    acc = (res[4] << 6) | (res[5] >> 2);
    if (acc > UINT14_MAX/2)
        acc -= UINT14_MAX;
    d[2] = acc;
}

void FXOS8700Q::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];
}

int16_t FXOS8700Q::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::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::writeRegs(uint8_t * data, int len) {
    m_i2c.write(m_addr, (char *)data, len);
}