MMA845x.h

00001 /**
00002  * @file    MMA845x.h
00003  * @brief   Device driver - MMA845x 3-axis accelerometer IC
00004  * @author  sam grove
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) 2013
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  */
00024  
00025 #ifndef MMA845X_H
00026 #define MMA845X_H
00027 
00028 #include "mbed.h"
00029 
00030 /** Using the Sparkfun SEN-10955
00031  *
00032  * Example:
00033  * @code
00034  *  #include "mbed.h"
00035  *  #include "MMA845x.h"
00036  *
00037 
00038  * 
00039  *  int main() 
00040  *  {
00041 
00042  *  }
00043  * @endcode
00044  */
00045 
00046 
00047 /**
00048  *  @class MMA845x_DATA
00049  *  @brief API abstraction for the MMA845x 3-axis accelerometer IC data
00050  */  
00051 class MMA845x_DATA
00052 {      
00053 public:
00054     
00055     volatile uint16_t _x ;   /*!< volatile data variable */
00056     volatile uint16_t _y ;   /*!< volatile data variable */
00057     volatile uint16_t _z ;   /*!< volatile data variable */
00058    
00059     /** Create the MMA845x_DATA object initialized to the parameter (or 0 if none)
00060      *  @param x - the init value of _x
00061      *  @param y - the init value of _y
00062      *  @param x - the init value of _z
00063      */
00064     MMA845x_DATA(uint16_t x = 0, uint16_t y = 0, uint16_t z = 0) : _x (x), _y (y), _z (z) {}
00065     
00066     /** Overloaded '=' operator to allow shorthand coding, assigning objects to one another
00067      *  @param rhs - an object of the same type to assign ourself the same values of
00068      *  @return this
00069      */
00070     MMA845x_DATA &operator= (MMA845x_DATA const &rhs)
00071     {
00072         _x  = rhs._x ;
00073         _y  = rhs._y ;
00074         _z  = rhs._z ;
00075         
00076         return *this;
00077     }
00078     
00079     /** Overloaded '=' operator to allow shorthand coding, assigning objects to one another
00080      *  @param val - Assign each data member (_x, _y, _z) this value
00081      *  @return this
00082      */
00083     MMA845x_DATA &operator= (uint16_t const val)
00084     {
00085         _x  = _y  = _z  = val;
00086         
00087         return *this;
00088     }
00089     
00090     /** Overloaded '==' operator to allow shorthand coding, test objects to one another
00091      *  @param rhs - the object to compare against
00092      *  @return 1 if the data members are the same and 0 otherwise
00093      */
00094     bool operator== (MMA845x_DATA const &rhs) const
00095     {
00096         return ((_x  == rhs._x )&&(_y  == rhs._y )&&(_z  == rhs._z )) ? 1 : 0;
00097     }
00098     
00099 };
00100 
00101 /**
00102  *  @class MMA845x
00103  *  @brief API abstraction for the MMA845x 3-axis accelerometer IC
00104  */ 
00105 class MMA845x
00106 {  
00107 public:
00108     
00109     /**
00110      *  @enum MMA845x_SA0
00111      *  @brief Possible terminations for the ADDR pin
00112      */ 
00113     enum MMA845x_SA0
00114     { 
00115         SA0_VSS  = 0, /*!< SA0 connected to VSS */
00116         SA0_VDD       /*!< SA0 connected to VDD */
00117     };
00118     
00119     /**
00120      *  @enum MMA845x_WHO_AM_I
00121      *  @brief Device ID's that this class is compatible with
00122      */ 
00123     enum MMA845x_WHO_AM_I
00124     { 
00125         MMA8451  = 0x1a, /*!< MMA8451 WHO_AM_I register content */
00126         MMA8452  = 0x2a, /*!< MMA8452 WHO_AM_I register content */
00127         MMA8453  = 0x3a, /*!< MMA8453 WHO_AM_I register content */
00128     };
00129     
00130     /**
00131      *  @enum MMA845x_REGISTER
00132      *  @brief The device register map
00133      */
00134     enum MMA845x_REGISTER
00135     {
00136         STATUS = 0x0,
00137         OUT_X_MSB, OUT_X_LSB, OUT_Y_MSB, OUT_Y_LSB, OUT_Z_MSB, OUT_Z_LSB,
00138         
00139         F_SETUP = 0x9, TRIG_CFG, // only available on the MMA8451 variant
00140         
00141         SYSMOD = 0xb,
00142         INT_SOURCE, WHO_AM_I, XYZ_DATA_CFG, HP_FILTER_CUTOFF, PL_STATUS,
00143         PL_CFG, PL_COUNT, PL_BF_ZCOMP, P_L_THS_REG, FF_MT_CFG, FF_MT_SRC,
00144         FF_MT_THS, FF_MT_COUNT,
00145         
00146         TRANSIENT_CFG = 0x1d,
00147         TRANSIENT_SRC, TRANSIENT_THS, TRANSIENT_COUNT, PULSE_CFG, PULSE_SRC,
00148         PULSE_THSX, PULSE_THSY, PULSE_THSZ, PULSE_TMLT, PULSE_LTCY, PULSE_WIND,
00149         ASLP_COUNT, CTRL_REG1, CTRL_REG2, CTRL_REG3, CTRL_REG4, CTRL_REG5,
00150         OFF_X, OFF_Y, OFF_Z
00151     };
00152         
00153     /** Create the MMA845x object
00154      *  @param i2c - A defined I2C object
00155      *  @param int1 - A defined InterruptIn object
00156      *  @param int2 - A defined InterruptIn object
00157      *  @param i2c_addr - Connection of the address line
00158      */ 
00159     MMA845x(I2C &i2c, InterruptIn &int1, InterruptIn &int2, MMA845x_SA0 const i2c_addr);
00160     
00161     /** Get the X data
00162      *  @return The last valid reading from the accelerometer
00163      */
00164     uint16_t getX(void) const;
00165     
00166     /** Get the Y data
00167      *  @return The last valid reading from the accelerometer
00168      */
00169     uint16_t getY(void) const;
00170     
00171     /** Get the Z data
00172      *  @return The last valid reading from the accelerometer
00173      */
00174     uint16_t getZ(void) const;
00175     
00176     /** Get the XYZ data structure
00177      *  @return The last valid reading from the accelerometer
00178      */
00179     MMA845x_DATA getXYZ(void) const;
00180     
00181     void enableDataReadyMode(void) const;
00182     void enableMotionMode(void) const;
00183     void enablePulseMode(void) const;
00184     void enableOrientationMode(void) const;
00185     void enableTransitMode(void) const;
00186     void enableAutoSleepMode(void) const;
00187     void enableFIFOMode(void) const;
00188     
00189     /** Put the MMA845x in the lowest possible power mode and suspend operation
00190      */
00191     void disable(void);
00192     
00193     /** Write to a register (exposed for debugging reasons)
00194      *  Note: most writes are only valid in stop mode
00195      *  @param reg - The register to be written
00196      *  @param data - The data to be written
00197      */
00198     void writeRegister(uint8_t const reg, uint8_t const data) const;
00199     
00200     /** Read from a register (exposed for debugging reasons)
00201      *  @param reg - The register to read from
00202      *  @return The register contents
00203      */
00204     uint8_t readRegister(uint8_t const reg) const;
00205     
00206     /** print the register map and values to the console
00207      */
00208     void registerDump(void) const;
00209     
00210 private:
00211     
00212     I2C         *_i2c;
00213     InterruptIn *_int1;
00214     InterruptIn *_int2;
00215     uint8_t      _i2c_addr;
00216     MMA845x_DATA _data;
00217     
00218     void init(void) const;
00219 };
00220 
00221 #endif