File content as of revision 0:0c4fafa398b4:

// based on http://mbed.org/users/Digixx/code/ADXL345/

/*
 * ADXL345, triple axis, I2C interface, accelerometer.
 *
 * Datasheet:
 *
 * http://www.analog.com/static/imported-files/data_sheets/ADXL345.pdf
 */  



#ifndef __ADXL345_H
#define __ADXL345_H

#include "mbed.h"

// register addresses
#define ADXL345_DEVID_REG          0x00
#define ADXL345_THRESH_TAP_REG     0x1D
#define ADXL345_OFSX_REG           0x1E
#define ADXL345_OFSY_REG           0x1F
#define ADXL345_OFSZ_REG           0x20
#define ADXL345_DUR_REG            0x21
#define ADXL345_LATENT_REG         0x22
#define ADXL345_WINDOW_REG         0x23
#define ADXL345_THRESH_ACT_REG     0x24
#define ADXL345_THRESH_INACT_REG   0x25
#define ADXL345_TIME_INACT_REG     0x26
#define ADXL345_ACT_INACT_CTL_REG  0x27
#define ADXL345_THRESH_FF_REG      0x28
#define ADXL345_TIME_FF_REG        0x29
#define ADXL345_TAP_AXES_REG       0x2A
#define ADXL345_ACT_TAP_STATUS_REG 0x2B
#define ADXL345_BW_RATE_REG        0x2C
#define ADXL345_POWER_CTL_REG      0x2D
#define ADXL345_INT_ENABLE_REG     0x2E
#define ADXL345_INT_MAP_REG        0x2F
#define ADXL345_INT_SOURCE_REG     0x30
#define ADXL345_DATA_FORMAT_REG    0x31
#define ADXL345_DATAX0_REG         0x32
#define ADXL345_DATAX1_REG         0x33
#define ADXL345_DATAY0_REG         0x34
#define ADXL345_DATAY1_REG         0x35
#define ADXL345_DATAZ0_REG         0x36
#define ADXL345_DATAZ1_REG         0x37

#define ADXL345_FIFO_CTL           0x38
#define ADXL345_FIFO_STATUS        0x39

// data rate codes
#define ADXL345_3200HZ      0x0F
#define ADXL345_1600HZ      0x0E
#define ADXL345_800HZ       0x0D
#define ADXL345_400HZ       0x0C
#define ADXL345_200HZ       0x0B
#define ADXL345_100HZ       0x0A
#define ADXL345_50HZ        0x09
#define ADXL345_25HZ        0x08
#define ADXL345_12HZ5       0x07
#define ADXL345_6HZ25       0x06

// read or write bytes
#define ADXL345_READ    0xA7  
#define ADXL345_WRITE   0xA6 
#define ADXL345_ADDRESS 0x53

//the ADXL345 7-bit address is 0x53 when ALT ADDRESS is low as it is on the sparkfun chip: when ALT ADDRESS is high the address is 0x1D

//when ALT ADDRESS pin is high:
//#define ADXL345_READ    0x3B   
//#define ADXL345_WRITE   0x3A
//#define ADXL345_ADDRESS 0x1D 

#define ADXL345_X           0x00
#define ADXL345_Y           0x01
#define ADXL345_Z           0x02

// modes
#define MeasurementMode     0x08







class ADXL345 {

public:

    /**
     * Constructor.
     *
     * @param mosi mbed pin to use for SDA line of I2C interface.
     * @param sck mbed pin to use for SCL line of I2C interface.
     */
    ADXL345(PinName sda, PinName scl);

    /**
     * Get the output of all three axes.
     *
     * @param Pointer to a buffer to hold the accelerometer value for the
     *        x-axis, y-axis and z-axis [in that order].
     */
    void getOutput(int* readings);

    /**
     * Read the device ID register on the device.
     *
     * @return The device ID code [0xE5]
     */
    char getDeviceID(void);
    
     /**
     * Set the power mode.
     *
     * @param mode 0 -> Normal operation.
     *             1 -> Reduced power operation.
     */     
    int setPowerMode(char mode);
  
     /**
     * Set the power control settings.
     *
     * See datasheet for details.
     *
     * @param The control byte to write to the POWER_CTL register.
     */
    int setPowerControl(char settings);     
      /**
     * Get the power control settings.
     *
     * See datasheet for details.
     *
     * @return The contents of the POWER_CTL register.
     */
    char getPowerControl(void);

       
    /**
     * Get the data format settings.
     *
     * @return The contents of the DATA_FORMAT register.
     */
     
    char getDataFormatControl(void);
    
    /**
     * Set the data format settings.
     *
     * @param settings The control byte to write to the DATA_FORMAT register.
     */
    int setDataFormatControl(char settings);
  
       /**
     * Set the data rate.
     *
     * @param rate The rate code (see #defines or datasheet).
     */
    int setDataRate(char rate);
    

       /**
     * Get the current offset for a particular axis.
     *
     * @param axis 0x00 -> X-axis
     *             0x01 -> Y-axis
     *             0x02 -> Z-axis
     * @return The current offset as an 8-bit 2's complement number with scale
     *         factor 15.6mg/LSB.
     */
     
    char getOffset(char axis);

    /**
     * Set the offset for a particular axis.
     *
     * @param axis 0x00 -> X-axis
     *             0x01 -> Y-axis
     *             0x02 -> Z-axis
     * @param offset The offset as an 8-bit 2's complement number with scale
     *               factor 15.6mg/LSB.
     */
    int setOffset(char axis, char offset);
    
    /**
     * Get the FIFO control settings.
     *
     * @return The contents of the FIFO_CTL register.
     */
    char getFifoControl(void);
    
    /**
     * Set the FIFO control settings.
     *
     * @param The control byte to write to the FIFO_CTL register.
     */
    int setFifoControl(char settings);
    
    /**
     * Get FIFO status.
     *
     * @return The contents of the FIFO_STATUS register.
     */
    char getFifoStatus(void);
    
    /**
     * Read the tap threshold on the device.
     *
     * @return The tap threshold as an 8-bit number with a scale factor of
     *         62.5mg/LSB.
     */
    char getTapThreshold(void);

    /**
     * Set the tap threshold.
     *
     * @param The tap threshold as an 8-bit number with a scale factor of
     *        62.5mg/LSB.
     */
    int setTapThreshold(char threshold);

    /**
     * Get the tap duration required to trigger an event.
     *
     * @return The max time that an event must be above the tap threshold to
     *         qualify as a tap event, in microseconds.
     */
    float getTapDuration(void);

    /**
     * Set the tap duration required to trigger an event.
     *
     * @param duration_us The max time that an event must be above the tap
     *                    threshold to qualify as a tap event, in microseconds.
     *                    Time will be normalized by the scale factor which is
     *                    625us/LSB. A value of 0 disables the single/double
     *                    tap functions.
     */
    int setTapDuration(short int duration_us);

    /**
     * Get the tap latency between the detection of a tap and the time window.
     *
     * @return The wait time from the detection of a tap event to the start of
     *         the time window during which a possible second tap event can be
     *         detected in milliseconds.
     */
    float getTapLatency(void);

    /**
     * Set the tap latency between the detection of a tap and the time window.
     *
     * @param latency_ms The wait time from the detection of a tap event to the
     *                   start of the time window during which a possible
     *                   second tap event can be detected in milliseconds.
     *                   A value of 0 disables the double tap function.
     */
    int setTapLatency(short int latency_ms);

    /**
     * Get the time of window between tap latency and a double tap.
     *
     * @return The amount of time after the expiration of the latency time
     *         during which a second valid tap can begin, in milliseconds.
     */
    float getWindowTime(void);

    /**
     * Set the time of the window between tap latency and a double tap.
     *
     * @param window_ms The amount of time after the expiration of the latency
     *                  time during which a second valid tap can begin,
     *                  in milliseconds.
     */
    int setWindowTime(short int window_ms);

    /**
     * Get the threshold value for detecting activity.
     *
     * @return The threshold value for detecting activity as an 8-bit number.
     *         Scale factor is 62.5mg/LSB.
     */
     char getActivityThreshold(void);

    /**
     * Set the threshold value for detecting activity.
     *
     * @param threshold The threshold value for detecting activity as an 8-bit
     *                  number. Scale factor is 62.5mg/LSB. A value of 0 may
     *                  result in undesirable behavior if the activity
     *                  interrupt is enabled.
     */
    int setActivityThreshold(char threshold);

    /**
     * Get the threshold value for detecting inactivity.
     *
     * @return The threshold value for detecting inactivity as an 8-bit number.
     *         Scale factor is 62.5mg/LSB.
     */
     char getInactivityThreshold(void);

    /**
     * Set the threshold value for detecting inactivity.
     *
     * @param threshold The threshold value for detecting inactivity as an
     *                  8-bit number. Scale factor is 62.5mg/LSB.
     */
    int setInactivityThreshold(char threshold);

    /**
     * Get the time required for inactivity to be declared.
     *
     * @return The amount of time that acceleration must be less than the
     *         inactivity threshold for inactivity to be declared, in
     *         seconds.
     */
     char getTimeInactivity(void);
    
    /**
     * Set the time required for inactivity to be declared.
     *
     * @param inactivity The amount of time that acceleration must be less than
     *                   the inactivity threshold for inactivity to be
     *                   declared, in seconds. A value of 0 results in an
     *                   interrupt when the output data is less than the
     *                   threshold inactivity.
     */
    int setTimeInactivity(char timeInactivity);
    
    /**
     * Get the activity/inactivity control settings.
     *
     *      D7            D6             D5            D4
     * +-----------+--------------+--------------+--------------+
     * | ACT ac/dc | ACT_X enable | ACT_Y enable | ACT_Z enable |
     * +-----------+--------------+--------------+--------------+
     *
     *        D3             D2               D1              D0
     * +-------------+----------------+----------------+----------------+
     * | INACT ac/dc | INACT_X enable | INACT_Y enable | INACT_Z enable |
     * +-------------+----------------+----------------+----------------+
     *
     * See datasheet for details.
     *
     * @return The contents of the ACT_INACT_CTL register.
     */
     char getActivityInactivityControl(void);
    
    /**
     * Set the activity/inactivity control settings.
     *
     *      D7            D6             D5            D4
     * +-----------+--------------+--------------+--------------+
     * | ACT ac/dc | ACT_X enable | ACT_Y enable | ACT_Z enable |
     * +-----------+--------------+--------------+--------------+
     *
     *        D3             D2               D1              D0
     * +-------------+----------------+----------------+----------------+
     * | INACT ac/dc | INACT_X enable | INACT_Y enable | INACT_Z enable |
     * +-------------+----------------+----------------+----------------+
     *
     * See datasheet for details.
     *
     * @param settings The control byte to write to the ACT_INACT_CTL register.
     */
    int setActivityInactivityControl(char settings);
    
    /**
     * Get the threshold for free fall detection.
     *
     * @return The threshold value for free-fall detection, as an 8-bit number,
     *         with scale factor 62.5mg/LSB.
     */
     char getFreefallThreshold(void);
    
    /**
     * Set the threshold for free fall detection.
     *
     * @return The threshold value for free-fall detection, as an 8-bit number,
     *         with scale factor 62.5mg/LSB. A value of 0 may result in 
     *         undesirable behavior if the free-fall interrupt is enabled.
     *         Values between 300 mg and 600 mg (0x05 to 0x09) are recommended.
     */
    int setFreefallThreshold(char threshold);
    
    /**
     * Get the time required to generate a free fall interrupt.
     *
     * @return The minimum time that the value of all axes must be less than
     *         the freefall threshold to generate a free-fall interrupt, in
     *         milliseconds.
     */
     char getFreefallTime(void);
    
    /**
     * Set the time required to generate a free fall interrupt.
     *
     * @return The minimum time that the value of all axes must be less than
     *         the freefall threshold to generate a free-fall interrupt, in
     *         milliseconds. A value of 0 may result in undesirable behavior
     *         if the free-fall interrupt is enabled. Values between 100 ms 
     *         and 350 ms (0x14 to 0x46) are recommended.
     */
    int setFreefallTime(short int freefallTime_ms);
    
    /**
     * Get the axis tap settings.
     *
     *      D3           D2            D1             D0
     * +----------+--------------+--------------+--------------+
     * | Suppress | TAP_X enable | TAP_Y enable | TAP_Z enable |
     * +----------+--------------+--------------+--------------+
     *
     * (D7-D4 are 0s).
     *
     * See datasheet for more details.
     *
     * @return The contents of the TAP_AXES register.
     */ 
     char getTapAxisControl(void);
    
    /**
     * Set the axis tap settings.
     *
     *      D3           D2            D1             D0
     * +----------+--------------+--------------+--------------+
     * | Suppress | TAP_X enable | TAP_Y enable | TAP_Z enable |
     * +----------+--------------+--------------+--------------+
     *
     * (D7-D4 are 0s).
     *
     * See datasheet for more details.
     *
     * @param The control byte to write to the TAP_AXES register.
     */
    int setTapAxisControl(char settings);
    
    /**
     * Get the source of a tap.
     *
     * @return The contents of the ACT_TAP_STATUS register.
     */
     char getTapSource(void);
    
     /**
     * Get the interrupt enable settings.
     *
     * @return The contents of the INT_ENABLE register.
     */

     char getInterruptEnableControl(void);
    
    /**
     * Set the interrupt enable settings.
     *
     * @param settings The control byte to write to the INT_ENABLE register.
     */
    int setInterruptEnableControl(char settings);
    
    /**
     * Get the interrupt mapping settings.
     *
     * @return The contents of the INT_MAP register.
     */
     char getInterruptMappingControl(void);
    
    /**
     * Set the interrupt mapping settings.
     *
     * @param settings The control byte to write to the INT_MAP register.
     */
    int setInterruptMappingControl(char settings);
    
    /**
     * Get the interrupt source.
     *
     * @return The contents of the INT_SOURCE register.
     */
     char getInterruptSource(void);
    
   
private:

    I2C i2c_;
    

    /**
     * Read one byte from a register on the device.
     *
     * @param: - the address to be read from
     *
     * @return: the value of the data read
     */
    char SingleByteRead(char address);

    /**
     * Write one byte to a register on the device.
     *
     * @param:
        - address of the register to write to.
        - the value of the data to store
     */
  
   
   int SingleByteWrite(char address, char data);

    /**
     * Read several consecutive bytes on the device and store them in a given location.
     *
     * @param startAddress: The address of the first register to read from.
     * @param ptr_output: a pointer to the location to store the data being read
     * @param size: The number of bytes to read.
     */
    void multiByteRead(char startAddress, char* ptr_output, int size);

    /**
     * Write several consecutive bytes  on the device.
     *
     * @param startAddress: The address of the first register to write to.
     * @param ptr_data: Pointer to a location which contains the data to write.
     * @param size: The number of bytes to write.
     */
    int multiByteWrite(char startAddress, char* ptr_data, int size);

};

#endif