ADXL345.cpp

00001 /**
00002  * @author Aaron Berk
00003  * 
00004  * @section LICENSE
00005  *
00006  * Copyright (c) 2010 ARM Limited
00007  *
00008  * Permission is hereby granted, free of charge, to any person obtaining a copy
00009  * of this software and associated documentation files (the "Software"), to deal
00010  * in the Software without restriction, including without limitation the rights
00011  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00012  * copies of the Software, and to permit persons to whom the Software is
00013  * furnished to do so, subject to the following conditions:
00014  *
00015  * The above copyright notice and this permission notice shall be included in
00016  * all copies or substantial portions of the Software.
00017  *
00018  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00019  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00020  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00021  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00022  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00023  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00024  * THE SOFTWARE.
00025  *
00026  * @section DESCRIPTION
00027  *
00028  * ADXL345, triple axis, digital interface, accelerometer.
00029  *
00030  * Datasheet:
00031  *
00032  * http://www.analog.com/static/imported-files/data_sheets/ADXL345.pdf
00033  */  
00034  
00035 /**
00036  * Includes
00037  */
00038 #include "ADXL345.h"
00039 
00040 ADXL345::ADXL345(PinName mosi, 
00041                  PinName miso, 
00042                  PinName sck, 
00043                  PinName cs) : spi_(mosi, miso, sck), nCS_(cs) {
00044 
00045     //2MHz, allowing us to use the fastest data rates.
00046     spi_.frequency(2000000);
00047     spi_.format(8,3);
00048     
00049     nCS_ = 1;
00050 
00051     wait_us(500);
00052 
00053 }
00054 
00055 int ADXL345::getDevId(void) {
00056 
00057     return oneByteRead(ADXL345_DEVID_REG);
00058 
00059 }
00060 
00061 int ADXL345::getTapThreshold(void) {
00062 
00063     return oneByteRead(ADXL345_THRESH_TAP_REG);
00064 
00065 }
00066 
00067 void ADXL345::setTapThreshold(int threshold) {
00068 
00069     oneByteWrite(ADXL345_THRESH_TAP_REG, threshold);
00070 
00071 }
00072 
00073 int ADXL345::getOffset(int axis) {
00074 
00075     int address = 0;
00076 
00077     if (axis == ADXL345_X) {
00078         address = ADXL345_OFSX_REG;
00079     } else if (axis == ADXL345_Y) {
00080         address = ADXL345_OFSY_REG;
00081     } else if (axis == ADXL345_Z) {
00082         address = ADXL345_OFSZ_REG;
00083     }
00084 
00085     return oneByteRead(address);
00086 
00087 }
00088 
00089 void ADXL345::setOffset(int axis, char offset) {
00090 
00091     int address = 0;
00092 
00093     if (axis == ADXL345_X) {
00094         address = ADXL345_OFSX_REG;
00095     } else if (axis == ADXL345_Y) {
00096         address = ADXL345_OFSY_REG;
00097     } else if (axis == ADXL345_Z) {
00098         address = ADXL345_OFSZ_REG;
00099     }
00100 
00101     return oneByteWrite(address, offset);
00102 
00103 }
00104 
00105 int ADXL345::getTapDuration(void) {
00106 
00107     return oneByteRead(ADXL345_DUR_REG)*625;
00108 
00109 }
00110 
00111 void ADXL345::setTapDuration(int duration_us) {
00112 
00113     int tapDuration = duration_us / 625;
00114 
00115     oneByteWrite(ADXL345_DUR_REG, tapDuration);
00116 
00117 }
00118 
00119 float ADXL345::getTapLatency(void) {
00120 
00121     return oneByteRead(ADXL345_LATENT_REG)*1.25;
00122 
00123 }
00124 
00125 void ADXL345::setTapLatency(int latency_ms) {
00126 
00127     int tapLatency = latency_ms / 1.25;
00128 
00129     oneByteWrite(ADXL345_LATENT_REG, tapLatency);
00130 
00131 }
00132 
00133 float ADXL345::getWindowTime(void) {
00134 
00135     return oneByteRead(ADXL345_WINDOW_REG)*1.25;
00136 
00137 }
00138 
00139 void ADXL345::setWindowTime(int window_ms) {
00140 
00141     int windowTime = window_ms / 1.25;
00142 
00143     oneByteWrite(ADXL345_WINDOW_REG, windowTime);
00144 
00145 }
00146 
00147 int ADXL345::getActivityThreshold(void) {
00148 
00149     return oneByteRead(ADXL345_THRESH_ACT_REG);
00150 
00151 }
00152 
00153 void ADXL345::setActivityThreshold(int threshold) {
00154 
00155     oneByteWrite(ADXL345_THRESH_ACT_REG, threshold);
00156 
00157 }
00158 
00159 int ADXL345::getInactivityThreshold(void) {
00160 
00161     return oneByteRead(ADXL345_THRESH_INACT_REG);
00162 
00163 }
00164 
00165 void ADXL345::setInactivityThreshold(int threshold) {
00166 
00167     return oneByteWrite(ADXL345_THRESH_INACT_REG, threshold);
00168 
00169 }
00170 
00171 int ADXL345::getTimeInactivity(void) {
00172 
00173     return oneByteRead(ADXL345_TIME_INACT_REG);
00174 
00175 }
00176 
00177 void ADXL345::setTimeInactivity(int timeInactivity) {
00178 
00179     oneByteWrite(ADXL345_TIME_INACT_REG, timeInactivity);
00180 
00181 }
00182 
00183 int ADXL345::getActivityInactivityControl(void) {
00184 
00185     return oneByteRead(ADXL345_ACT_INACT_CTL_REG);
00186 
00187 }
00188 
00189 void ADXL345::setActivityInactivityControl(int settings) {
00190 
00191     oneByteWrite(ADXL345_ACT_INACT_CTL_REG, settings);
00192 
00193 }
00194 
00195 int ADXL345::getFreefallThreshold(void) {
00196 
00197     return oneByteRead(ADXL345_THRESH_FF_REG);
00198 
00199 }
00200 
00201 void ADXL345::setFreefallThreshold(int threshold) {
00202 
00203     oneByteWrite(ADXL345_THRESH_FF_REG, threshold);
00204 
00205 }
00206 
00207 int ADXL345::getFreefallTime(void) {
00208 
00209     return oneByteRead(ADXL345_TIME_FF_REG)*5;
00210 
00211 }
00212 
00213 void ADXL345::setFreefallTime(int freefallTime_ms) {
00214 
00215     int freefallTime = freefallTime_ms / 5;
00216 
00217     oneByteWrite(ADXL345_TIME_FF_REG, freefallTime);
00218 
00219 }
00220 
00221 int ADXL345::getTapAxisControl(void) {
00222 
00223     return oneByteRead(ADXL345_TAP_AXES_REG);
00224 
00225 }
00226 
00227 void ADXL345::setTapAxisControl(int settings) {
00228 
00229     oneByteWrite(ADXL345_TAP_AXES_REG, settings);
00230 
00231 }
00232 
00233 int ADXL345::getTapSource(void) {
00234 
00235     return oneByteRead(ADXL345_ACT_TAP_STATUS_REG);
00236 
00237 }
00238 
00239 void ADXL345::setPowerMode(char mode) {
00240 
00241     //Get the current register contents, so we don't clobber the rate value.
00242     char registerContents = oneByteRead(ADXL345_BW_RATE_REG);
00243 
00244     registerContents = (mode << 4) | registerContents;
00245 
00246     oneByteWrite(ADXL345_BW_RATE_REG, registerContents);
00247 
00248 }
00249 
00250 int ADXL345::getPowerControl(void) {
00251 
00252     return oneByteRead(ADXL345_POWER_CTL_REG);
00253 
00254 }
00255 
00256 void ADXL345::setPowerControl(int settings) {
00257 
00258     oneByteWrite(ADXL345_POWER_CTL_REG, settings);
00259 
00260 }
00261 
00262 int ADXL345::getInterruptEnableControl(void) {
00263 
00264     return oneByteRead(ADXL345_INT_ENABLE_REG);
00265 
00266 }
00267 
00268 void ADXL345::setInterruptEnableControl(int settings) {
00269 
00270     oneByteWrite(ADXL345_INT_ENABLE_REG, settings);
00271 
00272 }
00273 
00274 int ADXL345::getInterruptMappingControl(void) {
00275 
00276     return oneByteRead(ADXL345_INT_MAP_REG);
00277 
00278 }
00279 
00280 void ADXL345::setInterruptMappingControl(int settings) {
00281 
00282     oneByteWrite(ADXL345_INT_MAP_REG, settings);
00283 
00284 }
00285 
00286 int ADXL345::getInterruptSource(void){
00287 
00288     return oneByteRead(ADXL345_INT_SOURCE_REG);
00289 
00290 }
00291 
00292 int ADXL345::getDataFormatControl(void){
00293 
00294     return oneByteRead(ADXL345_DATA_FORMAT_REG);
00295 
00296 }
00297 
00298 void ADXL345::setDataFormatControl(int settings){
00299 
00300     oneByteWrite(ADXL345_DATA_FORMAT_REG, settings);
00301 
00302 }
00303 
00304 void ADXL345::setDataRate(int rate) {
00305 
00306     //Get the current register contents, so we don't clobber the power bit.
00307     char registerContents = oneByteRead(ADXL345_BW_RATE_REG);
00308 
00309     registerContents &= 0x10;
00310     registerContents |= rate;
00311 
00312     oneByteWrite(ADXL345_BW_RATE_REG, registerContents);
00313 
00314 }
00315 
00316 void ADXL345::getOutput(int* readings){
00317 
00318     char buffer[6];
00319     
00320     multiByteRead(ADXL345_DATAX0_REG, buffer, 6);
00321     
00322     readings[0] = (int)buffer[1] << 8 | (int)buffer[0];
00323     readings[1] = (int)buffer[3] << 8 | (int)buffer[2];
00324     readings[2] = (int)buffer[5] << 8 | (int)buffer[4];
00325 
00326 }
00327 
00328 int ADXL345::getFifoControl(void){
00329 
00330     return oneByteRead(ADXL345_FIFO_CTL);
00331 
00332 }
00333 
00334 void ADXL345::setFifoControl(int settings){
00335 
00336     oneByteWrite(ADXL345_FIFO_STATUS, settings);
00337 
00338 }
00339 
00340 int ADXL345::getFifoStatus(void){
00341 
00342     return oneByteRead(ADXL345_FIFO_STATUS);
00343 
00344 }
00345 
00346 int ADXL345::oneByteRead(int address) {
00347 
00348     int tx = (ADXL345_SPI_READ | (address & 0x3F));
00349     int rx = 0;
00350 
00351     nCS_ = 0;
00352     //Send address to read from.
00353     spi_.write(tx);
00354     //Read back contents of address.
00355     rx = spi_.write(0x00);
00356     nCS_ = 1;
00357 
00358     return rx;
00359 
00360 }
00361 
00362 void ADXL345::oneByteWrite(int address, char data) {
00363 
00364     int tx = (ADXL345_SPI_WRITE | (address & 0x3F));
00365 
00366     nCS_ = 0;
00367     //Send address to write to.
00368     spi_.write(tx);
00369     //Send data to be written.
00370     spi_.write(data);
00371     nCS_ = 1;
00372 
00373 }
00374 
00375 void ADXL345::multiByteRead(int startAddress, char* buffer, int size) {
00376 
00377     int tx = (ADXL345_SPI_READ | ADXL345_MULTI_BYTE | (startAddress & 0x3F));
00378 
00379     nCS_ = 0;
00380     //Send address to start reading from.
00381     spi_.write(tx);
00382 
00383     for (int i = 0; i < size; i++) {
00384         buffer[i] = spi_.write(0x00);
00385     }
00386 
00387     nCS_ = 1;
00388 
00389 }
00390 
00391 void ADXL345::multiByteWrite(int startAddress, char* buffer, int size) {
00392 
00393     int tx = (ADXL345_SPI_WRITE | ADXL345_MULTI_BYTE | (startAddress & 0x3F));
00394 
00395     nCS_ = 0;
00396     //Send address to start reading from.
00397     spi_.write(tx);
00398 
00399     for (int i = 0; i < size; i++) {
00400         buffer[i] = spi_.write(0x00);
00401     }
00402 
00403     nCS_ = 1;
00404 
00405 }