ADXL345.cpp

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  * Includes
00051  */
00052 #include "ADXL345.h"
00053 
00054 //#include "mbed.h"
00055 
00056 ADXL345::ADXL345(PinName sda, PinName scl) : i2c_(sda, scl) {
00057 
00058     //400kHz, allowing us to use the fastest data rates.
00059     //there are other chips on board, sorry
00060     i2c_.frequency(100000);   
00061 // initialize the BW data rate
00062     char tx[2];
00063     tx[0] = ADXL345_BW_RATE_REG;
00064     tx[1] = ADXL345_1600HZ; //value greater than or equal to 0x0A is written into the rate bits (Bit D3 through Bit D0) in the BW_RATE register 
00065  i2c_.write( ADXL345_WRITE , tx, 2);  
00066 
00067 //Data format (for +-16g) - This is done by setting Bit D3 of the DATA_FORMAT register (Address 0x31) and writing a value of 0x03 to the range bits (Bit D1 and Bit D0) of the DATA_FORMAT register (Address 0x31).
00068    
00069  char rx[2];
00070     rx[0] = ADXL345_DATA_FORMAT_REG;
00071     rx[1] = 0x0B; 
00072      // full res and +_16g
00073  i2c_.write( ADXL345_WRITE , rx, 2); 
00074  
00075  // Set Offset  - programmed into the OFSX, OFSY, and OFXZ registers, respectively, as 0xFD, 0x03 and 0xFE.
00076   char x[2];
00077     x[0] = ADXL345_OFSX_REG ;
00078     x[1] = 0xFD; 
00079  i2c_.write( ADXL345_WRITE , x, 2);
00080   char y[2];
00081     y[0] = ADXL345_OFSY_REG ;
00082     y[1] = 0x03; 
00083  i2c_.write( ADXL345_WRITE , y, 2);
00084  char z[2];
00085     z[0] = ADXL345_OFSZ_REG ;
00086     z[1] = 0xFE; 
00087  i2c_.write( ADXL345_WRITE , z, 2);
00088 }
00089 
00090 
00091 char ADXL345::SingleByteRead(char address){   
00092    char tx = address;
00093    char output; 
00094     i2c_.write( ADXL345_WRITE , &tx, 1);  //tell it what you want to read
00095     i2c_.read( ADXL345_READ , &output, 1);    //tell it where to store the data
00096     return output;
00097   
00098 }
00099 
00100 
00101 /*
00102 ***info on the i2c_.write***
00103 address     8-bit I2C slave address [ addr | 0 ]
00104 data        Pointer to the byte-array data to send
00105 length        Number of bytes to send
00106 repeated    Repeated start, true - do not send stop at end
00107 returns     0 on success (ack), or non-0 on failure (nack)
00108 */
00109 
00110 int ADXL345::SingleByteWrite(char address, char data){ 
00111    int ack = 0;
00112    char tx[2];
00113    tx[0] = address;
00114    tx[1] = data;
00115    return   ack | i2c_.write( ADXL345_WRITE , tx, 2);   
00116 }
00117 
00118 
00119 
00120 void ADXL345::multiByteRead(char address, char* output, int size) {
00121     i2c_.write( ADXL345_WRITE, &address, 1);  //tell it where to read from
00122     i2c_.read( ADXL345_READ , output, size);      //tell it where to store the data read
00123 }
00124 
00125 
00126 int ADXL345::multiByteWrite(char address, char* ptr_data, int size) {
00127         int ack;
00128    
00129                ack = i2c_.write( ADXL345_WRITE, &address, 1);  //tell it where to write to
00130         return ack | i2c_.write( ADXL345_READ, ptr_data, size);  //tell it what data to write
00131                                     
00132 }
00133 
00134 
00135 void ADXL345::getOutput(int* readings){
00136     char buffer[6];    
00137     multiByteRead(ADXL345_DATAX0_REG, buffer, 6);
00138     
00139     readings[0] = (int)buffer[1] << 8 | (int)buffer[0];
00140     readings[1] = (int)buffer[3] << 8 | (int)buffer[2];
00141     readings[2] = (int)buffer[5] << 8 | (int)buffer[4];
00142 
00143 }
00144 
00145 
00146 
00147 char ADXL345::getDeviceID() {  
00148     return SingleByteRead(ADXL345_DEVID_REG);
00149     }
00150 //
00151 int ADXL345::setPowerMode(char mode) { 
00152 
00153     //Get the current register contents, so we don't clobber the rate value.
00154     char registerContents = (mode << 4) | SingleByteRead(ADXL345_BW_RATE_REG);
00155 
00156    return SingleByteWrite(ADXL345_BW_RATE_REG, registerContents);
00157 
00158 }
00159 
00160 char ADXL345::getPowerControl() {    
00161     return SingleByteRead(ADXL345_POWER_CTL_REG);
00162 }
00163 
00164 int ADXL345::setPowerControl(char settings) {    
00165     return SingleByteWrite(ADXL345_POWER_CTL_REG, settings);
00166 
00167 }
00168 
00169 
00170 
00171 char ADXL345::getDataFormatControl(void){
00172 
00173     return SingleByteRead(ADXL345_DATA_FORMAT_REG);
00174 }
00175 
00176 int ADXL345::setDataFormatControl(char settings){
00177 
00178    return SingleByteWrite(ADXL345_DATA_FORMAT_REG, settings);
00179     
00180 }
00181 
00182 int ADXL345::setDataRate(char rate) {
00183 
00184     //Get the current register contents, so we don't clobber the power bit.
00185     char registerContents = SingleByteRead(ADXL345_BW_RATE_REG);
00186 
00187     registerContents &= 0x10;
00188     registerContents |= rate;
00189 
00190     return SingleByteWrite(ADXL345_BW_RATE_REG, registerContents);
00191 
00192 }
00193 
00194 
00195 char ADXL345::getOffset(char axis) {     
00196 
00197     char address = 0;
00198 
00199     if (axis == ADXL345_X) {
00200         address = ADXL345_OFSX_REG;
00201     } else if (axis == ADXL345_Y) {
00202         address = ADXL345_OFSY_REG;
00203     } else if (axis == ADXL345_Z) {
00204         address = ADXL345_OFSZ_REG;
00205     }
00206 
00207    return SingleByteRead(address);
00208 }
00209 
00210 int ADXL345::setOffset(char axis, char offset) {        
00211 
00212     char address = 0;
00213 
00214     if (axis == ADXL345_X) {
00215         address = ADXL345_OFSX_REG;
00216     } else if (axis == ADXL345_Y) {
00217         address = ADXL345_OFSY_REG;
00218     } else if (axis == ADXL345_Z) {
00219         address = ADXL345_OFSZ_REG;
00220     }
00221 
00222    return SingleByteWrite(address, offset);
00223 
00224 }
00225 
00226 
00227 char ADXL345::getFifoControl(void){
00228 
00229     return SingleByteRead(ADXL345_FIFO_CTL);
00230 
00231 }
00232 
00233 int ADXL345::setFifoControl(char settings){
00234    return SingleByteWrite(ADXL345_FIFO_STATUS, settings);
00235 
00236 }
00237 
00238 char ADXL345::getFifoStatus(void){
00239 
00240     return SingleByteRead(ADXL345_FIFO_STATUS);
00241 
00242 }
00243 
00244 
00245 
00246 char ADXL345::getTapThreshold(void) {
00247 
00248     return SingleByteRead(ADXL345_THRESH_TAP_REG);
00249 }
00250 
00251 int ADXL345::setTapThreshold(char threshold) {   
00252 
00253    return SingleByteWrite(ADXL345_THRESH_TAP_REG, threshold);
00254 
00255 }
00256 
00257 
00258 float ADXL345::getTapDuration(void) {     
00259 
00260     return (float)SingleByteRead(ADXL345_DUR_REG)*625;
00261 }
00262 
00263 int ADXL345::setTapDuration(short int duration_us) {
00264 
00265     short int tapDuration = duration_us / 625;
00266     char tapChar[2];
00267      tapChar[0] = (tapDuration & 0x00FF);
00268      tapChar[1] = (tapDuration >> 8) & 0x00FF;
00269     return multiByteWrite(ADXL345_DUR_REG, tapChar, 2);
00270 
00271 }
00272 
00273 float ADXL345::getTapLatency(void) {
00274 
00275     return (float)SingleByteRead(ADXL345_LATENT_REG)*1.25;
00276 }
00277 
00278 int ADXL345::setTapLatency(short int latency_ms) {
00279 
00280     latency_ms = latency_ms / 1.25;
00281     char latChar[2];
00282      latChar[0] = (latency_ms & 0x00FF);
00283      latChar[1] = (latency_ms << 8) & 0xFF00;
00284     return multiByteWrite(ADXL345_LATENT_REG, latChar, 2);
00285 
00286 }
00287 
00288 float ADXL345::getWindowTime(void) {
00289 
00290     return (float)SingleByteRead(ADXL345_WINDOW_REG)*1.25;
00291 }
00292 
00293 int ADXL345::setWindowTime(short int window_ms) {
00294 
00295     window_ms = window_ms / 1.25;
00296     char windowChar[2];
00297     windowChar[0] = (window_ms & 0x00FF);
00298     windowChar[1] = ((window_ms << 8) & 0xFF00);
00299    return multiByteWrite(ADXL345_WINDOW_REG, windowChar, 2);
00300 
00301 }
00302 
00303 char ADXL345::getActivityThreshold(void) {
00304 
00305     return SingleByteRead(ADXL345_THRESH_ACT_REG);
00306 }
00307 
00308 int ADXL345::setActivityThreshold(char threshold) {
00309     return SingleByteWrite(ADXL345_THRESH_ACT_REG, threshold);
00310 
00311 }
00312 
00313 char ADXL345::getInactivityThreshold(void) {
00314     return SingleByteRead(ADXL345_THRESH_INACT_REG);
00315        
00316 }
00317 
00318 //int FUNCTION(short int * ptr_Output)
00319 //short int FUNCTION ()
00320 
00321 int ADXL345::setInactivityThreshold(char threshold) {
00322     return SingleByteWrite(ADXL345_THRESH_INACT_REG, threshold);
00323 
00324 }
00325 
00326 char ADXL345::getTimeInactivity(void) {
00327 
00328     return SingleByteRead(ADXL345_TIME_INACT_REG);
00329 
00330 }
00331 
00332 int ADXL345::setTimeInactivity(char timeInactivity) {
00333     return SingleByteWrite(ADXL345_TIME_INACT_REG, timeInactivity);
00334 
00335 }
00336 
00337 char ADXL345::getActivityInactivityControl(void) {
00338 
00339     return SingleByteRead(ADXL345_ACT_INACT_CTL_REG);
00340 
00341 }
00342 
00343 int ADXL345::setActivityInactivityControl(char settings) {
00344     return SingleByteWrite(ADXL345_ACT_INACT_CTL_REG, settings);
00345     
00346 }
00347 
00348 char ADXL345::getFreefallThreshold(void) {
00349 
00350     return SingleByteRead(ADXL345_THRESH_FF_REG);
00351 
00352 }
00353 
00354 int ADXL345::setFreefallThreshold(char threshold) {
00355    return SingleByteWrite(ADXL345_THRESH_FF_REG, threshold);
00356 
00357 }
00358 
00359 char ADXL345::getFreefallTime(void) {
00360 
00361     return SingleByteRead(ADXL345_TIME_FF_REG)*5;
00362 
00363 }
00364 
00365 int ADXL345::setFreefallTime(short int freefallTime_ms) {
00366      freefallTime_ms = freefallTime_ms / 5;
00367      char fallChar[2];
00368      fallChar[0] = (freefallTime_ms & 0x00FF);
00369      fallChar[1] = (freefallTime_ms << 8) & 0xFF00;
00370     
00371     return multiByteWrite(ADXL345_TIME_FF_REG, fallChar, 2);
00372 
00373 }
00374 
00375 char ADXL345::getTapAxisControl(void) {
00376 
00377     return SingleByteRead(ADXL345_TAP_AXES_REG);
00378 
00379 }
00380 
00381 int ADXL345::setTapAxisControl(char settings) {
00382    return SingleByteWrite(ADXL345_TAP_AXES_REG, settings);
00383 
00384 }
00385 
00386 char ADXL345::getTapSource(void) {
00387 
00388     return SingleByteRead(ADXL345_ACT_TAP_STATUS_REG);
00389 
00390 }
00391 
00392 
00393 
00394 char ADXL345::getInterruptEnableControl(void) {
00395 
00396     return SingleByteRead(ADXL345_INT_ENABLE_REG);
00397 
00398 }
00399 
00400 int ADXL345::setInterruptEnableControl(char settings) {
00401    return SingleByteWrite(ADXL345_INT_ENABLE_REG, settings);
00402 
00403 }
00404 
00405 char ADXL345::getInterruptMappingControl(void) {
00406 
00407     return SingleByteRead(ADXL345_INT_MAP_REG);
00408 
00409 }
00410 
00411 int ADXL345::setInterruptMappingControl(char settings) {
00412     return SingleByteWrite(ADXL345_INT_MAP_REG, settings);
00413 
00414 }
00415 
00416 char ADXL345::getInterruptSource(void){
00417 
00418     return SingleByteRead(ADXL345_INT_SOURCE_REG);
00419 
00420 }
00421 
00422 
00423 
00424