Thomas Murphy / FXOS8700CQ Featured

An in-development library to provide effective access to all features of the FXOS8700CQ on the FRDM-K64F mbed-enabled development board. As of 28 May 2014 1325EDT, the code should be generally usable and modifiable.

Dependents:   fxos8700cq_example frdm_fxos8700_logger AVC_test1 frdm_accel ... more

A basic implementation of accessing the FXOS8700CQ. This should be useable, but as the Apache License says, don't expect it to be good at doing anything, even what it's supposed to do.

FXOS8700CQ.h

Committer:
trm
Date:
2014-05-28
Revision:
0:cf6299acfe98
Child:
1:3ec7e2676e48

File content as of revision 0:cf6299acfe98:

#ifndef FXOS8700CQ_H
#define FXOS8700CQ_H

#include "mbed.h" // Building this for the mbed platform

#define I2C_400K 400000

// FXOS8700CQ I2C address
#define FXOS8700CQ_SLAVE_ADDR0 (0x1E<<1) // with pins SA0=0, SA1=0
#define FXOS8700CQ_SLAVE_ADDR1 (0x1D<<1) // with pins SA0=1, SA1=0
#define FXOS8700CQ_SLAVE_ADDR2 (0x1C<<1) // with pins SA0=0, SA1=1
#define FXOS8700CQ_SLAVE_ADDR3 (0x1F<<1) // with pins SA0=1, SA1=1

// FXOS8700CQ internal register addresses
#define FXOS8700CQ_STATUS 0x00
#define FXOS8700CQ_OUT_X_MSB 0x01
#define FXOS8700CQ_WHOAMI 0x0D
#define FXOS8700CQ_XYZ_DATA_CFG 0x0E
#define FXOS8700CQ_CTRL_REG1 0x2A
#define FXOS8700CQ_CTRL_REG2 0x2B
#define FXOS8700CQ_CTRL_REG3 0x2C
#define FXOS8700CQ_CTRL_REG4 0x2D
#define FXOS8700CQ_CTRL_REG5 0x2E

#define FXOS8700CQ_M_OUT_X_MSB 0x34

#define FXOS8700CQ_M_CTRL_REG1 0x5B
#define FXOS8700CQ_M_CTRL_REG2 0x5C
#define FXOS8700CQ_M_CTRL_REG3 0x5D

// FXOS8700CQ WHOAMI production register value
#define FXOS8700CQ_WHOAMI_VAL 0xC7

// 6 channels of two bytes = 12 bytes; read from FXOS8700CQ_OUT_X_MSB
#define FXOS8700CQ_READ_LEN 12

// From mbed I2C documentation for complete read/write transactions
#define I2C_SUCCESS 0
#define I2C_FAILURE 1

// For processing the accelerometer data to right-justified 2's complement
#define UINT14_MAX 16383

// TODO: struct to hold the data out of the sensor
typedef struct {
    int16_t x;
    int16_t y;
    int16_t z;
} SRAWDATA;

class FXOS8700CQ
{
public:
    /**
    * FXOS8700CQ constructor
    *
    * @param sda SDA pin
    * @param sdl SCL pin
    * @param addr address of the I2C peripheral in (7-bit << 1) form
    */

    FXOS8700CQ(PinName sda, PinName scl, int addr);

    /**
    * FXOS8700CQ destructor
    */
    ~FXOS8700CQ();

    void enable(void);
    void disable(void);
    uint8_t get_whoami(void);
    uint8_t status(void);
    void get_data(SRAWDATA *accel_data, SRAWDATA *magn_data);



private:
    I2C dev_i2c; // instance of the mbed I2C class
    uint8_t dev_addr; // Device I2C address, in (7-bit << 1) form

    // I2C helper methods
    void read_regs(int reg_addr, uint8_t* data, int len);
    void write_regs(uint8_t* data, int len);

};

#endif