MMA845x.h

00001 /**
00002  * @file    MMA845x.h
00003  * @brief   Device driver - MMA845x 3-axis accelerometer IC
00004  * @author  Tim Barr
00005  * @version 1.0
00006  * @see     http://cache.freescale.com/files/sensors/doc/data_sheet/MMA8451Q.pdf
00007  * @see     http://cache.freescale.com/files/sensors/doc/data_sheet/MMA8452Q.pdf
00008  * @see     http://cache.freescale.com/files/sensors/doc/data_sheet/MMA8453Q.pdf
00009  *
00010  * Copyright (c) 2015
00011  *
00012  * Licensed under the Apache License, Version 2.0 (the "License");
00013  * you may not use this file except in compliance with the License.
00014  * You may obtain a copy of the License at
00015  *
00016  *     http://www.apache.org/licenses/LICENSE-2.0
00017  *
00018  * Unless required by applicable law or agreed to in writing, software
00019  * distributed under the License is distributed on an "AS IS" BASIS,
00020  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00021  * See the License for the specific language governing permissions and
00022  * limitations under the License.
00023  * Forked from 
00024  */
00025  
00026 #ifndef MMA845X_H
00027 #define MMA845X_H
00028 
00029 #include "mbed.h"
00030 
00031 /** Using the Sparkfun SEN-10955
00032  *
00033  * Example:
00034  * @code
00035  *  #include "mbed.h"
00036  *  #include "MMA845x.h"
00037  *
00038 
00039  * 
00040  *  int main() 
00041  *  {
00042 
00043  *  }
00044  * @endcode
00045  */
00046 
00047 
00048 /**
00049  *  @class MMA845x_DATA
00050  *  @brief API abstraction for the MMA845x 3-axis accelerometer IC data
00051  */  
00052 class MMA845x_DATA
00053 {      
00054 public:
00055     
00056     volatile int16_t _x ;   /*!< volatile data variable */
00057     volatile int16_t _y ;   /*!< volatile data variable */
00058     volatile int16_t _z ;   /*!< volatile data variable */
00059    
00060     /** Create the MMA845x_DATA object initialized to the parameter (or 0 if none)
00061      *  @param x - the init value of _x
00062      *  @param y - the init value of _y
00063      *  @param x - the init value of _z
00064      */
00065     MMA845x_DATA(int16_t x = 0, int16_t y = 0, int16_t z = 0) : _x (x), _y (y), _z (z) {}
00066     
00067     /** Overloaded '=' operator to allow shorthand coding, assigning objects to one another
00068      *  @param rhs - an object of the same type to assign ourself the same values of
00069      *  @return this
00070      */
00071     MMA845x_DATA &operator= (MMA845x_DATA const &rhs)
00072     {
00073         _x  = rhs._x ;
00074         _y  = rhs._y ;
00075         _z  = rhs._z ;
00076         
00077         return *this;
00078     }
00079     
00080     /** Overloaded '=' operator to allow shorthand coding, assigning objects to one another
00081      *  @param val - Assign each data member (_x, _y, _z) this value
00082      *  @return this
00083      */
00084     MMA845x_DATA &operator= (int16_t const val)
00085     {
00086         _x  = _y  = _z  = val;
00087         
00088         return *this;
00089     }
00090     
00091     /** Overloaded '==' operator to allow shorthand coding, test objects to one another
00092      *  @param rhs - the object to compare against
00093      *  @return 1 if the data members are the same and 0 otherwise
00094      */
00095     bool operator== (MMA845x_DATA const &rhs) const
00096     {
00097         return ((_x  == rhs._x )&&(_y  == rhs._y )&&(_z  == rhs._z )) ? 1 : 0;
00098     }
00099 };
00100 
00101 /**
00102  *  @class MMA845x
00103  *  @brief API abstraction for the MMA845x 3-axis accelerometer IC
00104  *  initial version will be polling only. Interrupt service and rtos support will
00105  *  be added at a later point
00106  */ 
00107 class MMA845x
00108 {  
00109 public:
00110     
00111     /**
00112      *  @enum SA0
00113      *  @brief Possible terminations for the ADDR pin
00114      */ 
00115     enum SA0
00116     { 
00117         SA0_VSS  = 0, /*!< SA0 connected to VSS */
00118         SA0_VDD       /*!< SA0 connected to VDD */
00119     };
00120     
00121     /**
00122      *  @enum WHO_AM_I_VAL
00123      *  @brief Device ID's that this class is compatible with
00124      */ 
00125     enum WHO_AM_I_VAL
00126     { 
00127         MMA8451  = 0x1a, /*!< MMA8451 WHO_AM_I register content */
00128         MMA8452  = 0x2a, /*!< MMA8452 WHO_AM_I register content */
00129         MMA8453  = 0x3a, /*!< MMA8453 WHO_AM_I register content */
00130     };
00131 
00132     /**
00133      * @enum SYS_MODE
00134      * @brief operating mode of MMA845x
00135      */
00136     enum SYS_MODE
00137     {
00138         STANDBY = 0,
00139         WAKE, SLEEP
00140     };
00141 
00142     /**
00143      * @enum STATUS
00144      * @brief flags for data overwrite and data ready
00145      */
00146     enum STATUS
00147     {
00148         XDR   = 0x01,
00149         YDR   = 0x02,
00150         ZDR   = 0x04,
00151         XYZDR = 0x08,
00152         XOW   = 0x10,
00153         YOW   = 0x20,
00154         ZOW   = 0x40,
00155         XYZOW = 0x80
00156     };
00157 
00158   /**
00159      * @enum RANGE
00160      * @brief values for measurement range positive and negative
00161      */
00162     enum RANGE
00163     {
00164         RANGE_2g = 0,
00165         RANGE_4g, RANGE_8g
00166     };
00167     
00168     /**
00169      * @enum RESOLUTION
00170      * @brief selections for resolution of data, 8 bit or maximum
00171      */
00172     enum RESOLUTION
00173     {
00174         RES_MAX = 0,   /* Read back full resolution - normal mode*/
00175         RES_8BIT = 2   /* Read back 8 bit values only - fast mode*/
00176     };
00177 
00178     /**
00179      *  @enum LOW_NOISE
00180      *  @brief Low Noise mode Note: 4g max reading when on
00181      */
00182     enum LOW_NOISE
00183     {
00184         LN_OFF = 0x00, /* Low Noise mode off */
00185         LN_ON = 0x02  /* Low Noise mode on, 4g max readings */
00186     };
00187 
00188     /**
00189      *  @enum HPF_MODE
00190      *  @brief High Pass Filter mode
00191      */
00192     enum HPF_MODE
00193     {
00194         HPF_OFF = 0x00, /* High Pass Filter mode off */
00195         HPF_ON = 0x10  /* High Pass Filter mode on */
00196     };
00197 
00198      /**
00199      * @enum DATA_RATE
00200      * @brief values for normal output data rate in Hz
00201      */
00202     enum DATA_RATE
00203     {
00204         DR_800  = 0x00,
00205         DR_400  = 0x08,
00206         DR_200  = 0x10,
00207         DR_100  = 0x18,
00208         DR_50   = 0x20,
00209         DR_12_5 = 0x28,
00210         DR_6_25 = 0x30,
00211         DR_1_56 = 0x38
00212     };
00213     /**
00214      * @enum ASLP_DATA_RATE
00215      * @brief values for auto_sleep mode data rate in HZ
00216      */
00217     enum ASLP_DATA_RATE
00218     {
00219         ASLPDR_50   = 0x00,
00220         ALSPDR_12_5 = 0x40,
00221         ASLPDR_6_25 = 0x80,
00222         ASLPDR_1_56 = 0xB0
00223     };
00224 
00225     /**
00226      *  @enum OVERSAMPLE_MODE
00227      *  @brief sets the oversample mode, Normal, Low power and noise, High resolution, or low power
00228      */
00229     enum OVERSAMPLE_MODE
00230     {
00231         OS_NORMAL = 0,
00232         OS_LO_PN, OS_HI_RES, OS_LO_POW
00233     };
00234 
00235     /**
00236      *  @enum REGISTER
00237      *  @brief The device register map
00238      */
00239     enum REGISTER
00240     {
00241         STATUS = 0x00,
00242         OUT_X_MSB, OUT_X_LSB, OUT_Y_MSB, OUT_Y_LSB, OUT_Z_MSB, OUT_Z_LSB,
00243         
00244         F_SETUP = 0x09, TRIG_CFG, // only available on the MMA8451 variant
00245         
00246         SYSMOD = 0x0B,
00247         INT_SOURCE, WHO_AM_I, XYZ_DATA_CFG, HP_FILTER_CUTOFF, PL_STATUS,
00248         PL_CFG, PL_COUNT, PL_BF_ZCOMP, P_L_THS_REG, FF_MT_CFG, FF_MT_SRC,
00249         FF_MT_THS, FF_MT_COUNT,
00250         
00251         TRANSIENT_CFG = 0x1D,
00252         TRANSIENT_SRC, TRANSIENT_THS, TRANSIENT_COUNT, PULSE_CFG, PULSE_SRC,
00253         PULSE_THSX, PULSE_THSY, PULSE_THSZ, PULSE_TMLT, PULSE_LTCY, PULSE_WIND,
00254         ASLP_COUNT, CTRL_REG1, CTRL_REG2, CTRL_REG3, CTRL_REG4, CTRL_REG5,
00255         OFF_X, OFF_Y, OFF_Z
00256     };
00257         
00258     /** Create the MMA845x object
00259      *  @param i2c - A defined I2C object
00260      *  @param int1 - A defined InterruptIn object pointer. Default NULL for polling mode
00261      *  @param int2 - A defined InterruptIn object pointer. Default NULL for polling mode
00262      *  @param i2c_addr - state of pin SA0
00263      *  TODO - need to add interrupt support
00264      */ 
00265     MMA845x(I2C &i2c, SA0 const i2c_addr = SA0_VSS , InterruptIn* int1 = NULL, InterruptIn* int2 = NULL);
00266     
00267     /** Get the X data
00268      *  @return The last valid X-axis reading from the accelerometer
00269      */
00270     int16_t getX(void);
00271     
00272     /** Get the Y data
00273      *  @return The last valid Y-axis reading from the accelerometer
00274      */
00275     int16_t getY(void);
00276     
00277     /** Get the Z data
00278      *  @return The last Z-axis valid reading from the accelerometer
00279      */
00280     int16_t getZ(void);
00281     
00282     /** Get the XYZ data structure
00283      *  @return The last valid X, Y, and Z-axis readings from the accelerometer
00284      */
00285     MMA845x_DATA getXYZ(void);
00286     
00287     /** Get the XYZ data structure
00288      *  @return accelerometer ID code. Test versus the WHO_AM_I_VAL enum
00289      */
00290     char getWhoAmI(void) const;
00291 
00292     /** Setup the MMA845x for standard accelerometer read mode
00293      *  @range - set the measurement range using RANGE enum
00294      *  @resolution - set the ADC resolution using the RESOLUTION enum
00295      *  @lo_noise - Set the Low-Noise mode using the LOW_NOISE enum
00296      *  @data_rate - set the aquisition rate using the DATA_RATE enum
00297      *  @os_mode - Set the Over sample mode suing the OVERSAMPLE_MODE enum
00298      *  @hpf_mode - Set the Hi pass filter mode using the HPF_MOSE enum
00299      *  @return status of command
00300      *
00301      *  This sets the resolution, range, data rate, oversample
00302      *  mode, hi and lo pass filter.
00303      */
00304     uint8_t setCommonParameters(RANGE range, RESOLUTION resolution, LOW_NOISE lo_noise,
00305                                 DATA_RATE data_rate, OVERSAMPLE_MODE os_mode, HPF_MODE hpf_mode ) const;
00306 
00307     /** Ebnable Motion detect mode and interrupt handler
00308      *  @return status of command
00309      *  TODO - need to implement function
00310      */
00311     uint8_t enableMotionDetect(void) const;
00312 
00313     /** Enable Pulse Detect mode and interrupt handler
00314      *  @return status of command
00315      *  TODO - need to implement function
00316      */
00317     uint8_t enablePulseDetect(void) const;
00318 
00319     /** Enable Orientation mode and interrupt handler
00320      *  @return status of command
00321      *  TODO - need to implement function
00322      */
00323     uint8_t enableOrientationDetect(void) const;
00324 
00325     /** Enable Transient detect mode and interrupt handler
00326      *  @return status of command
00327      *  TODO - need to implement function
00328      */
00329     uint8_t enableTransientDetect(void) const;
00330 
00331     /** Enable Autosleep function and interrupt handler
00332      *  @return status of command
00333      *  TODO - need to implement function
00334      */
00335     uint8_t enableAutoSleep(void) const;
00336 
00337     /** Enbale FIFO function and interrupt handler
00338      *  @return status of command
00339      *  TODO - need to implement function
00340      */
00341     uint8_t enableFIFO(void) const;
00342     
00343     /** Put the MMA845x in the Standby mode
00344      *  @return status of command
00345      */
00346     uint8_t standbyMode(void) const;
00347  
00348     /** Put the MMA845x in the active mode
00349      *  @return status of command
00350      */
00351     uint8_t activeMode(void) const;
00352     
00353     /** Check the MMA845x status register
00354          *  @return status byte
00355          */
00356     uint8_t getStatus(void) const;
00357 
00358     
00359 private:
00360     
00361     I2C         *_i2c;
00362     InterruptIn *_int1;
00363     InterruptIn *_int2;
00364     uint8_t      _i2c_addr;
00365     char         _who_am_i;
00366     MMA845x_DATA _data;
00367     bool         _polling_mode;
00368     
00369     uint8_t init(void);
00370     
00371     /** Write to a register (exposed for debugging reasons)
00372      *  Note: most writes are only valid in stop mode
00373      *  @param reg - The register to be written
00374      *  @param data - The data to be written
00375      */
00376     uint8_t writeRegister(uint8_t const reg, uint8_t const data) const;
00377     
00378     /** Read from a register (exposed for debugging reasons)
00379      *  @param reg - The register to read from
00380      *  @return The register contents
00381      */
00382     uint8_t readRegister(uint8_t const reg, uint8_t count, char* data) const;
00383     
00384 
00385 };
00386 
00387 #endif