ADXL345_I2C.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_I2C.h"
00053 
00054 //#include "mbed.h"
00055 
00056 ADXL345_I2C::ADXL345_I2C(PinName sda, PinName scl) : i2c_(sda, scl) {
00057 
00058     //400kHz, allowing us to use the fastest data rates.
00059     i2c_.frequency(400000);   
00060 // initialize the BW data rate
00061     char tx[2];
00062     tx[0] = ADXL345_BW_RATE_REG;
00063     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 
00064  i2c_.write( ADXL345_I2C_WRITE , tx, 2);  
00065 
00066 //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).
00067    
00068  char rx[2];
00069     rx[0] = ADXL345_DATA_FORMAT_REG;
00070     rx[1] = 0x0B; 
00071      // full res and +_16g
00072  i2c_.write( ADXL345_I2C_WRITE , rx, 2); 
00073  
00074  // Set Offset  - programmed into the OFSX, OFSY, and OFXZ registers, respectively, as 0xFD, 0x03 and 0xFE.
00075   char x[2];
00076     x[0] = ADXL345_OFSX_REG ;
00077     x[1] = 0xFD; 
00078  i2c_.write( ADXL345_I2C_WRITE , x, 2);
00079   char y[2];
00080     y[0] = ADXL345_OFSY_REG ;
00081     y[1] = 0x03; 
00082  i2c_.write( ADXL345_I2C_WRITE , y, 2);
00083  char z[2];
00084     z[0] = ADXL345_OFSZ_REG ;
00085     z[1] = 0xFE; 
00086  i2c_.write( ADXL345_I2C_WRITE , z, 2);
00087 }
00088 
00089 
00090 char ADXL345_I2C::SingleByteRead(char address){   
00091    char tx = address;
00092    char output; 
00093     i2c_.write( ADXL345_I2C_WRITE , &tx, 1);  //tell it what you want to read
00094     i2c_.read( ADXL345_I2C_READ , &output, 1);    //tell it where to store the data
00095     return output;
00096   
00097 }
00098 
00099 
00100 /*
00101 ***info on the i2c_.write***
00102 address     8-bit I2C slave address [ addr | 0 ]
00103 data        Pointer to the byte-array data to send
00104 length        Number of bytes to send
00105 repeated    Repeated start, true - do not send stop at end
00106 returns     0 on success (ack), or non-0 on failure (nack)
00107 */
00108 
00109 int ADXL345_I2C::SingleByteWrite(char address, char data){ 
00110    int ack = 0;
00111    char tx[2];
00112    tx[0] = address;
00113    tx[1] = data;
00114    return   ack | i2c_.write( ADXL345_I2C_WRITE , tx, 2);   
00115 }
00116 
00117 
00118 
00119 void ADXL345_I2C::multiByteRead(char address, char* output, int size) {
00120     i2c_.write( ADXL345_I2C_WRITE, &address, 1);  //tell it where to read from
00121     i2c_.read( ADXL345_I2C_READ , output, size);      //tell it where to store the data read
00122 }
00123 
00124 
00125 int ADXL345_I2C::multiByteWrite(char address, char* ptr_data, int size) {
00126         int ack;
00127    
00128                ack = i2c_.write( ADXL345_I2C_WRITE, &address, 1);  //tell it where to write to
00129         return ack | i2c_.write( ADXL345_I2C_READ, ptr_data, size);  //tell it what data to write
00130                                     
00131 }
00132 
00133 
00134 void ADXL345_I2C::getOutput(int* readings){
00135     char buffer[6];    
00136     multiByteRead(ADXL345_DATAX0_REG, buffer, 6);
00137     
00138     readings[0] = (int)buffer[1] << 8 | (int)buffer[0];
00139     readings[1] = (int)buffer[3] << 8 | (int)buffer[2];
00140     readings[2] = (int)buffer[5] << 8 | (int)buffer[4];
00141 
00142 }
00143 
00144 
00145 
00146 char ADXL345_I2C::getDeviceID() {  
00147     return SingleByteRead(ADXL345_DEVID_REG);
00148     }
00149 //
00150 int ADXL345_I2C::setPowerMode(char mode) { 
00151 
00152     //Get the current register contents, so we don't clobber the rate value.
00153     char registerContents = (mode << 4) | SingleByteRead(ADXL345_BW_RATE_REG);
00154 
00155    return SingleByteWrite(ADXL345_BW_RATE_REG, registerContents);
00156 
00157 }
00158 
00159 char ADXL345_I2C::getPowerControl() {    
00160     return SingleByteRead(ADXL345_POWER_CTL_REG);
00161 }
00162 
00163 int ADXL345_I2C::setPowerControl(char settings) {    
00164     return SingleByteWrite(ADXL345_POWER_CTL_REG, settings);
00165 
00166 }
00167 
00168 
00169 
00170 char ADXL345_I2C::getDataFormatControl(void){
00171 
00172     return SingleByteRead(ADXL345_DATA_FORMAT_REG);
00173 }
00174 
00175 int ADXL345_I2C::setDataFormatControl(char settings){
00176 
00177    return SingleByteWrite(ADXL345_DATA_FORMAT_REG, settings);
00178     
00179 }
00180 
00181 int ADXL345_I2C::setDataRate(char rate) {
00182 
00183     //Get the current register contents, so we don't clobber the power bit.
00184     char registerContents = SingleByteRead(ADXL345_BW_RATE_REG);
00185 
00186     registerContents &= 0x10;
00187     registerContents |= rate;
00188 
00189     return SingleByteWrite(ADXL345_BW_RATE_REG, registerContents);
00190 
00191 }
00192 
00193 
00194 char ADXL345_I2C::getOffset(char axis) {     
00195 
00196     char address = 0;
00197 
00198     if (axis == ADXL345_X) {
00199         address = ADXL345_OFSX_REG;
00200     } else if (axis == ADXL345_Y) {
00201         address = ADXL345_OFSY_REG;
00202     } else if (axis == ADXL345_Z) {
00203         address = ADXL345_OFSZ_REG;
00204     }
00205 
00206    return SingleByteRead(address);
00207 }
00208 
00209 int ADXL345_I2C::setOffset(char axis, char offset) {        
00210 
00211     char address = 0;
00212 
00213     if (axis == ADXL345_X) {
00214         address = ADXL345_OFSX_REG;
00215     } else if (axis == ADXL345_Y) {
00216         address = ADXL345_OFSY_REG;
00217     } else if (axis == ADXL345_Z) {
00218         address = ADXL345_OFSZ_REG;
00219     }
00220 
00221    return SingleByteWrite(address, offset);
00222 
00223 }
00224 
00225 
00226 char ADXL345_I2C::getFifoControl(void){
00227 
00228     return SingleByteRead(ADXL345_FIFO_CTL);
00229 
00230 }
00231 
00232 int ADXL345_I2C::setFifoControl(char settings){
00233    return SingleByteWrite(ADXL345_FIFO_STATUS, settings);
00234 
00235 }
00236 
00237 char ADXL345_I2C::getFifoStatus(void){
00238 
00239     return SingleByteRead(ADXL345_FIFO_STATUS);
00240 
00241 }
00242 
00243 
00244 
00245 char ADXL345_I2C::getTapThreshold(void) {
00246 
00247     return SingleByteRead(ADXL345_THRESH_TAP_REG);
00248 }
00249 
00250 int ADXL345_I2C::setTapThreshold(char threshold) {   
00251 
00252    return SingleByteWrite(ADXL345_THRESH_TAP_REG, threshold);
00253 
00254 }
00255 
00256 
00257 float ADXL345_I2C::getTapDuration(void) {     
00258 
00259     return (float)SingleByteRead(ADXL345_DUR_REG)*625;
00260 }
00261 
00262 int ADXL345_I2C::setTapDuration(short int duration_us) {
00263 
00264     short int tapDuration = duration_us / 625;
00265     char tapChar[2];
00266      tapChar[0] = (tapDuration & 0x00FF);
00267      tapChar[1] = (tapDuration >> 8) & 0x00FF;
00268     return multiByteWrite(ADXL345_DUR_REG, tapChar, 2);
00269 
00270 }
00271 
00272 float ADXL345_I2C::getTapLatency(void) {
00273 
00274     return (float)SingleByteRead(ADXL345_LATENT_REG)*1.25;
00275 }
00276 
00277 int ADXL345_I2C::setTapLatency(short int latency_ms) {
00278 
00279     latency_ms = latency_ms / 1.25;
00280     char latChar[2];
00281      latChar[0] = (latency_ms & 0x00FF);
00282      latChar[1] = (latency_ms << 8) & 0xFF00;
00283     return multiByteWrite(ADXL345_LATENT_REG, latChar, 2);
00284 
00285 }
00286 
00287 float ADXL345_I2C::getWindowTime(void) {
00288 
00289     return (float)SingleByteRead(ADXL345_WINDOW_REG)*1.25;
00290 }
00291 
00292 int ADXL345_I2C::setWindowTime(short int window_ms) {
00293 
00294     window_ms = window_ms / 1.25;
00295     char windowChar[2];
00296     windowChar[0] = (window_ms & 0x00FF);
00297     windowChar[1] = ((window_ms << 8) & 0xFF00);
00298    return multiByteWrite(ADXL345_WINDOW_REG, windowChar, 2);
00299 
00300 }
00301 
00302 char ADXL345_I2C::getActivityThreshold(void) {
00303 
00304     return SingleByteRead(ADXL345_THRESH_ACT_REG);
00305 }
00306 
00307 int ADXL345_I2C::setActivityThreshold(char threshold) {
00308     return SingleByteWrite(ADXL345_THRESH_ACT_REG, threshold);
00309 
00310 }
00311 
00312 char ADXL345_I2C::getInactivityThreshold(void) {
00313     return SingleByteRead(ADXL345_THRESH_INACT_REG);
00314        
00315 }
00316 
00317 //int FUNCTION(short int * ptr_Output)
00318 //short int FUNCTION ()
00319 
00320 int ADXL345_I2C::setInactivityThreshold(char threshold) {
00321     return SingleByteWrite(ADXL345_THRESH_INACT_REG, threshold);
00322 
00323 }
00324 
00325 char ADXL345_I2C::getTimeInactivity(void) {
00326 
00327     return SingleByteRead(ADXL345_TIME_INACT_REG);
00328 
00329 }
00330 
00331 int ADXL345_I2C::setTimeInactivity(char timeInactivity) {
00332     return SingleByteWrite(ADXL345_TIME_INACT_REG, timeInactivity);
00333 
00334 }
00335 
00336 char ADXL345_I2C::getActivityInactivityControl(void) {
00337 
00338     return SingleByteRead(ADXL345_ACT_INACT_CTL_REG);
00339 
00340 }
00341 
00342 int ADXL345_I2C::setActivityInactivityControl(char settings) {
00343     return SingleByteWrite(ADXL345_ACT_INACT_CTL_REG, settings);
00344     
00345 }
00346 
00347 char ADXL345_I2C::getFreefallThreshold(void) {
00348 
00349     return SingleByteRead(ADXL345_THRESH_FF_REG);
00350 
00351 }
00352 
00353 int ADXL345_I2C::setFreefallThreshold(char threshold) {
00354    return SingleByteWrite(ADXL345_THRESH_FF_REG, threshold);
00355 
00356 }
00357 
00358 char ADXL345_I2C::getFreefallTime(void) {
00359 
00360     return SingleByteRead(ADXL345_TIME_FF_REG)*5;
00361 
00362 }
00363 
00364 int ADXL345_I2C::setFreefallTime(short int freefallTime_ms) {
00365      freefallTime_ms = freefallTime_ms / 5;
00366      char fallChar[2];
00367      fallChar[0] = (freefallTime_ms & 0x00FF);
00368      fallChar[1] = (freefallTime_ms << 8) & 0xFF00;
00369     
00370     return multiByteWrite(ADXL345_TIME_FF_REG, fallChar, 2);
00371 
00372 }
00373 
00374 char ADXL345_I2C::getTapAxisControl(void) {
00375 
00376     return SingleByteRead(ADXL345_TAP_AXES_REG);
00377 
00378 }
00379 
00380 int ADXL345_I2C::setTapAxisControl(char settings) {
00381    return SingleByteWrite(ADXL345_TAP_AXES_REG, settings);
00382 
00383 }
00384 
00385 char ADXL345_I2C::getTapSource(void) {
00386 
00387     return SingleByteRead(ADXL345_ACT_TAP_STATUS_REG);
00388 
00389 }
00390 
00391 
00392 
00393 char ADXL345_I2C::getInterruptEnableControl(void) {
00394 
00395     return SingleByteRead(ADXL345_INT_ENABLE_REG);
00396 
00397 }
00398 
00399 int ADXL345_I2C::setInterruptEnableControl(char settings) {
00400    return SingleByteWrite(ADXL345_INT_ENABLE_REG, settings);
00401 
00402 }
00403 
00404 char ADXL345_I2C::getInterruptMappingControl(void) {
00405 
00406     return SingleByteRead(ADXL345_INT_MAP_REG);
00407 
00408 }
00409 
00410 int ADXL345_I2C::setInterruptMappingControl(char settings) {
00411     return SingleByteWrite(ADXL345_INT_MAP_REG, settings);
00412 
00413 }
00414 
00415 char ADXL345_I2C::getInterruptSource(void){
00416 
00417     return SingleByteRead(ADXL345_INT_SOURCE_REG);
00418 
00419 }
00420 
00421 
00422 
00423