This library enables users to communicate with the ADXL345 accelerometer through the I2C bus on the mbed. The API names are similar and work nearly the same way as those made in the SPI libraries for the ADXL345.

Dependencies:   mbed

Dependents:   sensors-example

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ADXL345_I2C.h

00001 /**
00002  * @author Peter Swanson
00003  * A personal note from me: Jesus Christ has changed my life so much it blows my mind. I say this because
00004  *                  today, religion is thought of as something that you do or believe and has about as
00005  *                  little impact on a person as their political stance. But for me, God gives me daily
00006  *                  strength and has filled my life with the satisfaction that I could never find in any
00007  *                  of the other things that I once looked for it in. 
00008  * If your interested, heres verse that changed my life:
00009  *      Rom 8:1-3: "Therefore, there is now no condemnation for those who are in Christ Jesus,
00010  *                  because through Christ Jesus, the law of the Spirit who gives life has set
00011  *                  me free from the law of sin (which brings...) and death. For what the law 
00012  *                  was powerless to do in that it was weakened by the flesh, God did by sending
00013  *                  His own Son in the likeness of sinful flesh to be a sin offering. And so He
00014  *                  condemned sin in the flesh in order that the righteous requirements of the 
00015  *                  (God's) law might be fully met in us, who live not according to the flesh
00016  *                  but according to the Spirit."
00017  *
00018  *  A special thanks to Ewout van Bekkum for all his patient help in developing this library!
00019  *
00020  * @section LICENSE
00021  *
00022  * Permission is hereby granted, free of charge, to any person obtaining a copy
00023  * of this software and associated documentation files (the "Software"), to deal
00024  * in the Software without restriction, including without limitation the rights
00025  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00026  * copies of the Software, and to permit persons to whom the Software is
00027  * furnished to do so, subject to the following conditions:
00028  *
00029  * The above copyright notice and this permission notice shall be included in
00030  * all copies or substantial portions of the Software.
00031  *
00032  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00033  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00034  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00035  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00036  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00037  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00038  * THE SOFTWARE.
00039  *
00040  * @section DESCRIPTION
00041  *
00042  * ADXL345, triple axis, I2C interface, accelerometer.
00043  *
00044  * Datasheet:
00045  *
00046  * http://www.analog.com/static/imported-files/data_sheets/ADXL345.pdf
00047  */  
00048 
00049 
00050 
00051 #ifndef ADXL345_I2C_H
00052 #define ADXL345_I2C_H
00053 
00054 /**
00055  * Includes
00056  */
00057 #include "mbed.h"
00058 
00059 /**
00060  * Defines
00061  */
00062 //Registers.
00063 #define ADXL345_DEVID_REG          0x00
00064 #define ADXL345_THRESH_TAP_REG     0x1D
00065 #define ADXL345_OFSX_REG           0x1E
00066 #define ADXL345_OFSY_REG           0x1F
00067 #define ADXL345_OFSZ_REG           0x20
00068 #define ADXL345_DUR_REG            0x21
00069 #define ADXL345_LATENT_REG         0x22
00070 #define ADXL345_WINDOW_REG         0x23
00071 #define ADXL345_THRESH_ACT_REG     0x24
00072 #define ADXL345_THRESH_INACT_REG   0x25
00073 #define ADXL345_TIME_INACT_REG     0x26
00074 #define ADXL345_ACT_INACT_CTL_REG  0x27
00075 #define ADXL345_THRESH_FF_REG      0x28
00076 #define ADXL345_TIME_FF_REG        0x29
00077 #define ADXL345_TAP_AXES_REG       0x2A
00078 #define ADXL345_ACT_TAP_STATUS_REG 0x2B
00079 #define ADXL345_BW_RATE_REG        0x2C
00080 #define ADXL345_POWER_CTL_REG      0x2D
00081 #define ADXL345_INT_ENABLE_REG     0x2E
00082 #define ADXL345_INT_MAP_REG        0x2F
00083 #define ADXL345_INT_SOURCE_REG     0x30
00084 #define ADXL345_DATA_FORMAT_REG    0x31
00085 #define ADXL345_DATAX0_REG         0x32
00086 #define ADXL345_DATAX1_REG         0x33
00087 #define ADXL345_DATAY0_REG         0x34
00088 #define ADXL345_DATAY1_REG         0x35
00089 #define ADXL345_DATAZ0_REG         0x36
00090 #define ADXL345_DATAZ1_REG         0x37
00091 #define ADXL345_FIFO_CTL           0x38
00092 #define ADXL345_FIFO_STATUS        0x39
00093 
00094 //Data rate codes.
00095 #define ADXL345_3200HZ      0x0F
00096 #define ADXL345_1600HZ      0x0E
00097 #define ADXL345_800HZ       0x0D
00098 #define ADXL345_400HZ       0x0C
00099 #define ADXL345_200HZ       0x0B
00100 #define ADXL345_100HZ       0x0A
00101 #define ADXL345_50HZ        0x09
00102 #define ADXL345_25HZ        0x08
00103 #define ADXL345_12HZ5       0x07
00104 #define ADXL345_6HZ25       0x06
00105 
00106 // read or write bytes
00107 #define ADXL345_I2C_READ    0xA7  
00108 #define ADXL345_I2C_WRITE   0xA6 
00109 #define ADXL345_I2C_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
00110 
00111 /////////////when ALT ADDRESS pin is high:
00112 //#define ADXL345_I2C_READ    0x3B   
00113 //#define ADXL345_I2C_WRITE   0x3A
00114 //#define ADXL345_I2C_ADDRESS 0x1D 
00115 
00116 #define ADXL345_X           0x00
00117 #define ADXL345_Y           0x01
00118 #define ADXL345_Z           0x02
00119 
00120 
00121 
00122 // modes
00123 #define MeasurementMode     0x08
00124 
00125 
00126 
00127 
00128 
00129 
00130 
00131 class ADXL345_I2C {
00132 
00133 public:
00134 
00135     /**
00136      * Constructor.
00137      *
00138      * @param mosi mbed pin to use for SDA line of I2C interface.
00139      * @param sck mbed pin to use for SCL line of I2C interface.
00140      */
00141     ADXL345_I2C(PinName sda, PinName scl);
00142 
00143     /**
00144      * Get the output of all three axes.
00145      *
00146      * @param Pointer to a buffer to hold the accelerometer value for the
00147      *        x-axis, y-axis and z-axis [in that order].
00148      */
00149     void getOutput(int* readings);
00150 
00151     /**
00152      * Read the device ID register on the device.
00153      *
00154      * @return The device ID code [0xE5]
00155      */
00156     char getDeviceID(void);
00157 
00158 
00159     
00160      /**
00161      * Set the power mode.
00162      *
00163      * @param mode 0 -> Normal operation.
00164      *             1 -> Reduced power operation.
00165      */     
00166 int setPowerMode(char mode);
00167   
00168      /**
00169      * Set the power control settings.
00170      *
00171      * See datasheet for details.
00172      *
00173      * @param The control byte to write to the POWER_CTL register.
00174      */
00175  int setPowerControl(char settings);     
00176       /**
00177      * Get the power control settings.
00178      *
00179      * See datasheet for details.
00180      *
00181      * @return The contents of the POWER_CTL register.
00182      */
00183     char getPowerControl(void);
00184 
00185        
00186     /**
00187      * Get the data format settings.
00188      *
00189      * @return The contents of the DATA_FORMAT register.
00190      */
00191      
00192     char getDataFormatControl(void);
00193     
00194     /**
00195      * Set the data format settings.
00196      *
00197      * @param settings The control byte to write to the DATA_FORMAT register.
00198      */
00199     int setDataFormatControl(char settings);
00200   
00201        /**
00202      * Set the data rate.
00203      *
00204      * @param rate The rate code (see #defines or datasheet).
00205      */
00206     int setDataRate(char rate);
00207     
00208 
00209        /**
00210      * Get the current offset for a particular axis.
00211      *
00212      * @param axis 0x00 -> X-axis
00213      *             0x01 -> Y-axis
00214      *             0x02 -> Z-axis
00215      * @return The current offset as an 8-bit 2's complement number with scale
00216      *         factor 15.6mg/LSB.
00217      */
00218      
00219        char getOffset(char axis);
00220 
00221     /**
00222      * Set the offset for a particular axis.
00223      *
00224      * @param axis 0x00 -> X-axis
00225      *             0x01 -> Y-axis
00226      *             0x02 -> Z-axis
00227      * @param offset The offset as an 8-bit 2's complement number with scale
00228      *               factor 15.6mg/LSB.
00229      */
00230     int setOffset(char axis, char offset);
00231 
00232 
00233     
00234     /**
00235      * Get the FIFO control settings.
00236      *
00237      * @return The contents of the FIFO_CTL register.
00238      */
00239     char getFifoControl(void);
00240     
00241     /**
00242      * Set the FIFO control settings.
00243      *
00244      * @param The control byte to write to the FIFO_CTL register.
00245      */
00246     int setFifoControl(char settings);
00247     
00248     /**
00249      * Get FIFO status.
00250      *
00251      * @return The contents of the FIFO_STATUS register.
00252      */
00253     char getFifoStatus(void);
00254     
00255     /**
00256      * Read the tap threshold on the device.
00257      *
00258      * @return The tap threshold as an 8-bit number with a scale factor of
00259      *         62.5mg/LSB.
00260      */
00261     char getTapThreshold(void);
00262 
00263     /**
00264      * Set the tap threshold.
00265      *
00266      * @param The tap threshold as an 8-bit number with a scale factor of
00267      *        62.5mg/LSB.
00268      */
00269     int setTapThreshold(char threshold);
00270 
00271     /**
00272      * Get the tap duration required to trigger an event.
00273      *
00274      * @return The max time that an event must be above the tap threshold to
00275      *         qualify as a tap event, in microseconds.
00276      */
00277     float getTapDuration(void);
00278 
00279     /**
00280      * Set the tap duration required to trigger an event.
00281      *
00282      * @param duration_us The max time that an event must be above the tap
00283      *                    threshold to qualify as a tap event, in microseconds.
00284      *                    Time will be normalized by the scale factor which is
00285      *                    625us/LSB. A value of 0 disables the single/double
00286      *                    tap functions.
00287      */
00288     int setTapDuration(short int duration_us);
00289 
00290     /**
00291      * Get the tap latency between the detection of a tap and the time window.
00292      *
00293      * @return The wait time from the detection of a tap event to the start of
00294      *         the time window during which a possible second tap event can be
00295      *         detected in milliseconds.
00296      */
00297     float getTapLatency(void);
00298 
00299     /**
00300      * Set the tap latency between the detection of a tap and the time window.
00301      *
00302      * @param latency_ms The wait time from the detection of a tap event to the
00303      *                   start of the time window during which a possible
00304      *                   second tap event can be detected in milliseconds.
00305      *                   A value of 0 disables the double tap function.
00306      */
00307     int setTapLatency(short int latency_ms);
00308 
00309     /**
00310      * Get the time of window between tap latency and a double tap.
00311      *
00312      * @return The amount of time after the expiration of the latency time
00313      *         during which a second valid tap can begin, in milliseconds.
00314      */
00315     float getWindowTime(void);
00316 
00317     /**
00318      * Set the time of the window between tap latency and a double tap.
00319      *
00320      * @param window_ms The amount of time after the expiration of the latency
00321      *                  time during which a second valid tap can begin,
00322      *                  in milliseconds.
00323      */
00324     int setWindowTime(short int window_ms);
00325 
00326     /**
00327      * Get the threshold value for detecting activity.
00328      *
00329      * @return The threshold value for detecting activity as an 8-bit number.
00330      *         Scale factor is 62.5mg/LSB.
00331      */
00332      char getActivityThreshold(void);
00333 
00334     /**
00335      * Set the threshold value for detecting activity.
00336      *
00337      * @param threshold The threshold value for detecting activity as an 8-bit
00338      *                  number. Scale factor is 62.5mg/LSB. A value of 0 may
00339      *                  result in undesirable behavior if the activity
00340      *                  interrupt is enabled.
00341      */
00342     int setActivityThreshold(char threshold);
00343 
00344     /**
00345      * Get the threshold value for detecting inactivity.
00346      *
00347      * @return The threshold value for detecting inactivity as an 8-bit number.
00348      *         Scale factor is 62.5mg/LSB.
00349      */
00350      char getInactivityThreshold(void);
00351 
00352     /**
00353      * Set the threshold value for detecting inactivity.
00354      *
00355      * @param threshold The threshold value for detecting inactivity as an
00356      *                  8-bit number. Scale factor is 62.5mg/LSB.
00357      */
00358     int setInactivityThreshold(char threshold);
00359 
00360     /**
00361      * Get the time required for inactivity to be declared.
00362      *
00363      * @return The amount of time that acceleration must be less than the
00364      *         inactivity threshold for inactivity to be declared, in
00365      *         seconds.
00366      */
00367      char getTimeInactivity(void);
00368     
00369     /**
00370      * Set the time required for inactivity to be declared.
00371      *
00372      * @param inactivity The amount of time that acceleration must be less than
00373      *                   the inactivity threshold for inactivity to be
00374      *                   declared, in seconds. A value of 0 results in an
00375      *                   interrupt when the output data is less than the
00376      *                   threshold inactivity.
00377      */
00378     int setTimeInactivity(char timeInactivity);
00379     
00380     /**
00381      * Get the activity/inactivity control settings.
00382      *
00383      *      D7            D6             D5            D4
00384      * +-----------+--------------+--------------+--------------+
00385      * | ACT ac/dc | ACT_X enable | ACT_Y enable | ACT_Z enable |
00386      * +-----------+--------------+--------------+--------------+
00387      *
00388      *        D3             D2               D1              D0
00389      * +-------------+----------------+----------------+----------------+
00390      * | INACT ac/dc | INACT_X enable | INACT_Y enable | INACT_Z enable |
00391      * +-------------+----------------+----------------+----------------+
00392      *
00393      * See datasheet for details.
00394      *
00395      * @return The contents of the ACT_INACT_CTL register.
00396      */
00397      char getActivityInactivityControl(void);
00398     
00399     /**
00400      * Set the activity/inactivity control settings.
00401      *
00402      *      D7            D6             D5            D4
00403      * +-----------+--------------+--------------+--------------+
00404      * | ACT ac/dc | ACT_X enable | ACT_Y enable | ACT_Z enable |
00405      * +-----------+--------------+--------------+--------------+
00406      *
00407      *        D3             D2               D1              D0
00408      * +-------------+----------------+----------------+----------------+
00409      * | INACT ac/dc | INACT_X enable | INACT_Y enable | INACT_Z enable |
00410      * +-------------+----------------+----------------+----------------+
00411      *
00412      * See datasheet for details.
00413      *
00414      * @param settings The control byte to write to the ACT_INACT_CTL register.
00415      */
00416     int setActivityInactivityControl(char settings);
00417     
00418     /**
00419      * Get the threshold for free fall detection.
00420      *
00421      * @return The threshold value for free-fall detection, as an 8-bit number,
00422      *         with scale factor 62.5mg/LSB.
00423      */
00424      char getFreefallThreshold(void);
00425     
00426     /**
00427      * Set the threshold for free fall detection.
00428      *
00429      * @return The threshold value for free-fall detection, as an 8-bit number,
00430      *         with scale factor 62.5mg/LSB. A value of 0 may result in 
00431      *         undesirable behavior if the free-fall interrupt is enabled.
00432      *         Values between 300 mg and 600 mg (0x05 to 0x09) are recommended.
00433      */
00434     int setFreefallThreshold(char threshold);
00435     
00436     /**
00437      * Get the time required to generate a free fall interrupt.
00438      *
00439      * @return The minimum time that the value of all axes must be less than
00440      *         the freefall threshold to generate a free-fall interrupt, in
00441      *         milliseconds.
00442      */
00443      char getFreefallTime(void);
00444     
00445     /**
00446      * Set the time required to generate a free fall interrupt.
00447      *
00448      * @return The minimum time that the value of all axes must be less than
00449      *         the freefall threshold to generate a free-fall interrupt, in
00450      *         milliseconds. A value of 0 may result in undesirable behavior
00451      *         if the free-fall interrupt is enabled. Values between 100 ms 
00452      *         and 350 ms (0x14 to 0x46) are recommended.
00453      */
00454     int setFreefallTime(short int freefallTime_ms);
00455     
00456     /**
00457      * Get the axis tap settings.
00458      *
00459      *      D3           D2            D1             D0
00460      * +----------+--------------+--------------+--------------+
00461      * | Suppress | TAP_X enable | TAP_Y enable | TAP_Z enable |
00462      * +----------+--------------+--------------+--------------+
00463      *
00464      * (D7-D4 are 0s).
00465      *
00466      * See datasheet for more details.
00467      *
00468      * @return The contents of the TAP_AXES register.
00469      */ 
00470      char getTapAxisControl(void);
00471     
00472     /**
00473      * Set the axis tap settings.
00474      *
00475      *      D3           D2            D1             D0
00476      * +----------+--------------+--------------+--------------+
00477      * | Suppress | TAP_X enable | TAP_Y enable | TAP_Z enable |
00478      * +----------+--------------+--------------+--------------+
00479      *
00480      * (D7-D4 are 0s).
00481      *
00482      * See datasheet for more details.
00483      *
00484      * @param The control byte to write to the TAP_AXES register.
00485      */
00486     int setTapAxisControl(char settings);
00487     
00488     /**
00489      * Get the source of a tap.
00490      *
00491      * @return The contents of the ACT_TAP_STATUS register.
00492      */
00493      char getTapSource(void);
00494     
00495      /**
00496      * Get the interrupt enable settings.
00497      *
00498      * @return The contents of the INT_ENABLE register.
00499      */
00500 
00501      char getInterruptEnableControl(void);
00502     
00503     /**
00504      * Set the interrupt enable settings.
00505      *
00506      * @param settings The control byte to write to the INT_ENABLE register.
00507      */
00508     int setInterruptEnableControl(char settings);
00509     
00510     /**
00511      * Get the interrupt mapping settings.
00512      *
00513      * @return The contents of the INT_MAP register.
00514      */
00515      char getInterruptMappingControl(void);
00516     
00517     /**
00518      * Set the interrupt mapping settings.
00519      *
00520      * @param settings The control byte to write to the INT_MAP register.
00521      */
00522     int setInterruptMappingControl(char settings);
00523     
00524     /**
00525      * Get the interrupt source.
00526      *
00527      * @return The contents of the INT_SOURCE register.
00528      */
00529      char getInterruptSource(void);
00530     
00531    
00532 private:
00533 
00534     I2C i2c_;
00535     
00536 
00537     /**
00538      * Read one byte from a register on the device.
00539      *
00540      * @param: - the address to be read from
00541      *
00542      * @return: the value of the data read
00543      */
00544     char SingleByteRead(char address);
00545 
00546     /**
00547      * Write one byte to a register on the device.
00548      *
00549      * @param:
00550         - address of the register to write to.
00551         - the value of the data to store
00552      */
00553   
00554    
00555    int SingleByteWrite(char address, char data);
00556 
00557     /**
00558      * Read several consecutive bytes on the device and store them in a given location.
00559      *
00560      * @param startAddress: The address of the first register to read from.
00561      * @param ptr_output: a pointer to the location to store the data being read
00562      * @param size: The number of bytes to read.
00563      */
00564     void multiByteRead(char startAddress, char* ptr_output, int size);
00565 
00566     /**
00567      * Write several consecutive bytes  on the device.
00568      *
00569      * @param startAddress: The address of the first register to write to.
00570      * @param ptr_data: Pointer to a location which contains the data to write.
00571      * @param size: The number of bytes to write.
00572      */
00573     int multiByteWrite(char startAddress, char* ptr_data, int size);
00574 
00575 };
00576 
00577 #endif /* ADXL345_I2C_H */