Library for the MMA7660 triple axis accelerometer

Dependents:   Websocket_Ethernet_acc app-board-Sprint-WS-Acc app-board-Ethernet-Websocket app-board-Wifly-Websocket ... more

MMA7660.h

Committer:
Sissors
Date:
2012-10-16
Revision:
1:8997a1b348dd
Parent:
0:7bc29a9ea016
Child:
2:a8e20db7901e

File content as of revision 1:8997a1b348dd:

#include "mbed.h"


#ifndef MMA7660_H
#define MMA7660_H

#define MMA7660_ADDRESS     0x98
#define MMA7660_SENSITIVITY 21.33

#define MMA7660_XOUT_R      0x00
#define MMA7660_YOUT_R      0x01
#define MMA7660_ZOUT_R      0x02
#define MMA7660_TILT_R      0x03
#define MMA7660_INT_R       0x06
#define MMA7660_MODE_R      0x07
#define MMA7660_SR_R        0x08


class MMA7660
{
public:
    /** 
    * The 6 different orientations and unknown
    *
    * Up & Down = X-axis
    * Right & Left = Y-axis
    * Back & Front = Z-axis
    * 
    */
    enum Orientation{Up, Down,
                    Right, Left,
                    Back, Front,
                    Unknown};
    
    /**
    * Creates a new MMA7660 object
    *
    * @param sda - I2C data pin
    * @param scl - I2C clock pin
    * @param interrupt - Interrupt pin (default = NC)
    */
    MMA7660(PinName sda, PinName scl, PinName interrupt = NC);

    /**
    * Tests if communication is possible with the MMA7660
    *
    * Because the MMA7660 lacks a WHO_AM_I register, this function can only check
    * if there is an I2C device that responds to the MMA7660 address
    *
    * @param return - true for successfull connection, false for no connection
    */
    bool testConnection( void );
    
    /**
    * Sets the active state of the MMA7660
    *
    * Note: This is unrelated to awake/sleep mode
    *
    * @param state - true for active, false for standby
    */
    void setActive( bool state);
    
    /**
    * Reads acceleration data from the sensor
    *
    * When the parameter is a pointer to an integer array it will be the raw data. 
    * When it is a pointer to a float array it will be the acceleration in g's
    * 
    * @param data - pointer to array with length 3 where the acceleration data will be stores, X-Y-Z
    */
    void readData( int *data);
    void readData( float *data);
    
    /** 
    * Get X-data
    *
    * @param return - X-acceleration in g's
    */
    float getX( void );
    
    /** 
    * Get Y-data
    *
    * @param return - Y-acceleration in g's
    */
    float getY( void );
    
    /** 
    * Get Z-data
    *
    * @param return - Z-acceleration in g's
    */
    float getZ( void );
    
    /** 
    * Sets the active samplerate
    *
    * The entered samplerate will be rounded to nearest supported samplerate.
    * Supported samplerates are: 120 - 64 - 32 - 16 - 8 - 4 - 2 - 1 samples/second.
    *
    * @param samplerate - the samplerate that will be set
    */
    void setSampleRate(int samplerate);        

    /**
    * Returns which side is pointing down
    *
    * @param return - Orientation which is closest to down
    */    
    Orientation getGlobalOrientation( void );
    
    /**
    * Returns if it is on its front, back, or unknown side
    *
    * This is read from MMA7760s registers, page 12 of datasheet
    *
    * @param return - Front, Back or Unknown orientation
    */
    Orientation getSide( void );
    
    /**
    * Returns if it is on it left, right, down or up side
    *
    * This is read from MMA7760s registers, page 12 of datasheet
    *
    * @param return - Left, Right, Down, Up or Unknown orientation
    */
    Orientation getOrientation ( void );
    
    /**
    * Returns if since last check there has been a tap
    *
    * @param return - bool that is true when a tap has been detected
    */    
    bool isTapped( void );



private:

    /**
    * Writes data to the device
    *
    * @param adress - register address to write to
    * @param data - data to write
    */
    void write( char address, char data);

    /**
    * Read data from the device
    *
    * @param adress - register address to write to
    * @return - data from the register specified by RA
    */
    char read( char adress);
    
    /**
     * Read multiple regigsters from the device, more efficient than using multiple normal reads. 
     *
     * @param adress - register address to write to
     * @param length - number of bytes to read
     * @param data - pointer where the data needs to be written to 
     */
     void read( char adress, char *data, int length);
     
     /**
     * Reads single axis
     */
     float getSingle(int number);

    I2C _i2c;
    bool active;
    PinName _interrupt;
    float samplerate;
};


#endif