ADXL345_I2C.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_I2C.h"
00039 
00040 ADXL345::ADXL345(PinName sda, PinName scl) {
00041 
00042     i2c_ = new I2C(sda, scl);
00043     //100KHz, as specified by the datasheet.
00044     i2c_->frequency(100000);
00045     //2MHz, allowing us to use the fastest data rates.
00046     
00047     wait_us(500);
00048 
00049 }
00050 
00051 int ADXL345::getDevId(void) {
00052 
00053     return oneByteRead(ADXL345_DEVID_REG);
00054 
00055 }
00056 
00057 int ADXL345::getTapThreshold(void) {
00058 
00059     return oneByteRead(ADXL345_THRESH_TAP_REG);
00060 
00061 }
00062 
00063 void ADXL345::setTapThreshold(int threshold) {
00064 
00065     oneByteWrite(ADXL345_THRESH_TAP_REG, threshold);
00066 
00067 }
00068 
00069 int ADXL345::getOffset(int axis) {
00070 
00071     int address = 0;
00072 
00073     if (axis == ADXL345_X) {
00074         address = ADXL345_OFSX_REG;
00075     } else if (axis == ADXL345_Y) {
00076         address = ADXL345_OFSY_REG;
00077     } else if (axis == ADXL345_Z) {
00078         address = ADXL345_OFSZ_REG;
00079     }
00080 
00081     return oneByteRead(address);
00082 
00083 }
00084 
00085 void ADXL345::setOffset(int axis, char offset) {
00086 
00087     int address = 0;
00088 
00089     if (axis == ADXL345_X) {
00090         address = ADXL345_OFSX_REG;
00091     } else if (axis == ADXL345_Y) {
00092         address = ADXL345_OFSY_REG;
00093     } else if (axis == ADXL345_Z) {
00094         address = ADXL345_OFSZ_REG;
00095     }
00096 
00097     return oneByteWrite(address, offset);
00098 
00099 }
00100 
00101 int ADXL345::getTapDuration(void) {
00102 
00103     return oneByteRead(ADXL345_DUR_REG)*625;
00104 
00105 }
00106 
00107 void ADXL345::setTapDuration(int duration_us) {
00108 
00109     int tapDuration = duration_us / 625;
00110 
00111     oneByteWrite(ADXL345_DUR_REG, tapDuration);
00112 
00113 }
00114 
00115 float ADXL345::getTapLatency(void) {
00116 
00117     return oneByteRead(ADXL345_LATENT_REG)*1.25;
00118 
00119 }
00120 
00121 void ADXL345::setTapLatency(int latency_ms) {
00122 
00123     int tapLatency = latency_ms / 1.25;
00124 
00125     oneByteWrite(ADXL345_LATENT_REG, tapLatency);
00126 
00127 }
00128 
00129 float ADXL345::getWindowTime(void) {
00130 
00131     return oneByteRead(ADXL345_WINDOW_REG)*1.25;
00132 
00133 }
00134 
00135 void ADXL345::setWindowTime(int window_ms) {
00136 
00137     int windowTime = window_ms / 1.25;
00138 
00139     oneByteWrite(ADXL345_WINDOW_REG, windowTime);
00140 
00141 }
00142 
00143 int ADXL345::getActivityThreshold(void) {
00144 
00145     return oneByteRead(ADXL345_THRESH_ACT_REG);
00146 
00147 }
00148 
00149 void ADXL345::setActivityThreshold(int threshold) {
00150 
00151     oneByteWrite(ADXL345_THRESH_ACT_REG, threshold);
00152 
00153 }
00154 
00155 int ADXL345::getInactivityThreshold(void) {
00156 
00157     return oneByteRead(ADXL345_THRESH_INACT_REG);
00158 
00159 }
00160 
00161 void ADXL345::setInactivityThreshold(int threshold) {
00162 
00163     return oneByteWrite(ADXL345_THRESH_INACT_REG, threshold);
00164 
00165 }
00166 
00167 int ADXL345::getTimeInactivity(void) {
00168 
00169     return oneByteRead(ADXL345_TIME_INACT_REG);
00170 
00171 }
00172 
00173 void ADXL345::setTimeInactivity(int timeInactivity) {
00174 
00175     oneByteWrite(ADXL345_TIME_INACT_REG, timeInactivity);
00176 
00177 }
00178 
00179 int ADXL345::getActivityInactivityControl(void) {
00180 
00181     return oneByteRead(ADXL345_ACT_INACT_CTL_REG);
00182 
00183 }
00184 
00185 void ADXL345::setActivityInactivityControl(int settings) {
00186 
00187     oneByteWrite(ADXL345_ACT_INACT_CTL_REG, settings);
00188 
00189 }
00190 
00191 int ADXL345::getFreefallThreshold(void) {
00192 
00193     return oneByteRead(ADXL345_THRESH_FF_REG);
00194 
00195 }
00196 
00197 void ADXL345::setFreefallThreshold(int threshold) {
00198 
00199     oneByteWrite(ADXL345_THRESH_FF_REG, threshold);
00200 
00201 }
00202 
00203 int ADXL345::getFreefallTime(void) {
00204 
00205     return oneByteRead(ADXL345_TIME_FF_REG)*5;
00206 
00207 }
00208 
00209 void ADXL345::setFreefallTime(int freefallTime_ms) {
00210 
00211     int freefallTime = freefallTime_ms / 5;
00212 
00213     oneByteWrite(ADXL345_TIME_FF_REG, freefallTime);
00214 
00215 }
00216 
00217 int ADXL345::getTapAxisControl(void) {
00218 
00219     return oneByteRead(ADXL345_TAP_AXES_REG);
00220 
00221 }
00222 
00223 void ADXL345::setTapAxisControl(int settings) {
00224 
00225     oneByteWrite(ADXL345_TAP_AXES_REG, settings);
00226 
00227 }
00228 
00229 int ADXL345::getTapSource(void) {
00230 
00231     return oneByteRead(ADXL345_ACT_TAP_STATUS_REG);
00232 
00233 }
00234 
00235 void ADXL345::setPowerMode(char mode) {
00236 
00237     //Get the current register contents, so we don't clobber the rate value.
00238     char registerContents = oneByteRead(ADXL345_BW_RATE_REG);
00239 
00240     registerContents = (mode << 4) | registerContents;
00241 
00242     oneByteWrite(ADXL345_BW_RATE_REG, registerContents);
00243 
00244 }
00245 
00246 int ADXL345::getPowerControl(void) {
00247 
00248     return oneByteRead(ADXL345_POWER_CTL_REG);
00249 
00250 }
00251 
00252 void ADXL345::setPowerControl(int settings) {
00253 
00254     oneByteWrite(ADXL345_POWER_CTL_REG, settings);
00255 
00256 }
00257 
00258 int ADXL345::getInterruptEnableControl(void) {
00259 
00260     return oneByteRead(ADXL345_INT_ENABLE_REG);
00261 
00262 }
00263 
00264 void ADXL345::setInterruptEnableControl(int settings) {
00265 
00266     oneByteWrite(ADXL345_INT_ENABLE_REG, settings);
00267 
00268 }
00269 
00270 int ADXL345::getInterruptMappingControl(void) {
00271 
00272     return oneByteRead(ADXL345_INT_MAP_REG);
00273 
00274 }
00275 
00276 void ADXL345::setInterruptMappingControl(int settings) {
00277 
00278     oneByteWrite(ADXL345_INT_MAP_REG, settings);
00279 
00280 }
00281 
00282 int ADXL345::getInterruptSource(void){
00283 
00284     return oneByteRead(ADXL345_INT_SOURCE_REG);
00285 
00286 }
00287 
00288 int ADXL345::getDataFormatControl(void){
00289 
00290     return oneByteRead(ADXL345_DATA_FORMAT_REG);
00291 
00292 }
00293 
00294 void ADXL345::setDataFormatControl(int settings){
00295 
00296     oneByteWrite(ADXL345_DATA_FORMAT_REG, settings);
00297 
00298 }
00299 
00300 void ADXL345::setDataRate(int rate) {
00301 
00302     //Get the current register contents, so we don't clobber the power bit.
00303     char registerContents = oneByteRead(ADXL345_BW_RATE_REG);
00304 
00305     registerContents &= 0x10;
00306     registerContents |= rate;
00307 
00308     oneByteWrite(ADXL345_BW_RATE_REG, registerContents);
00309 
00310 }
00311 
00312 void ADXL345::getOutput(int* readings){
00313 
00314     char buffer[6];
00315     
00316     multiByteRead(ADXL345_DATAX0_REG, buffer, 6);
00317     
00318     readings[0] = (int)buffer[1] << 8 | (int)buffer[0];
00319     readings[1] = (int)buffer[3] << 8 | (int)buffer[2];
00320     readings[2] = (int)buffer[5] << 8 | (int)buffer[4];
00321 
00322 }
00323 
00324 int ADXL345::getFifoControl(void){
00325 
00326     return oneByteRead(ADXL345_FIFO_CTL);
00327 
00328 }
00329 
00330 void ADXL345::setFifoControl(int settings){
00331 
00332     oneByteWrite(ADXL345_FIFO_STATUS, settings);
00333 
00334 }
00335 
00336 int ADXL345::getFifoStatus(void){
00337 
00338     return oneByteRead(ADXL345_FIFO_STATUS);
00339 
00340 }
00341 
00342 
00343 int ADXL345::oneByteRead(int address) {
00344 
00345     char rx[1];
00346     rx[0] = address;
00347     i2c_ -> write((ADXL345_I2C_ADDRESS << 1) & 0xFE, rx, 1);
00348     wait_ms(1);
00349     i2c_ -> read((ADXL345_I2C_ADDRESS << 1) | 0x01, rx, 1);
00350     wait_ms(1);
00351     return rx[0];
00352 }
00353 
00354 void ADXL345::oneByteWrite(int address, char data) {
00355 
00356     char tx[2];
00357     tx[0] = address;
00358     tx[1] = data;
00359     i2c_ -> write((ADXL345_I2C_ADDRESS << 1) & 0xFE, tx, 2);
00360     wait_ms(1);
00361 
00362 }
00363 
00364 void ADXL345::multiByteRead(int address, char* data, int bytes) {
00365 
00366     char cmd[6];
00367     cmd[0] = address;
00368     i2c_ -> write((ADXL345_I2C_ADDRESS << 1) & 0xFE, cmd, 1);
00369     wait_ms(1);
00370     i2c_ -> read((ADXL345_I2C_ADDRESS << 1) | 0x01, data, bytes );
00371     wait_ms(1);
00372 
00373 }
00374 
00375 /*void ADXL345::multiByteWrite(int startAddress, char* buffer, int size) {
00376 
00377     int tx = (ADXL345_SPI_WRITE | 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 }*/