LSM9DS1.cpp

00001 /******************************************************************************
00002 SFE_LSM9DS1.cpp
00003 SFE_LSM9DS1 Library Source File
00004 Jim Lindblom @ SparkFun Electronics
00005 Original Creation Date: February 27, 2015
00006 https://github.com/sparkfun/LSM9DS1_Breakout
00007 
00008 This file implements all functions of the LSM9DS1 class. Functions here range
00009 from higher level stuff, like reading/writing LSM9DS1 registers to low-level,
00010 hardware reads and writes. Both SPI and I2C handler functions can be found
00011 towards the bottom of this file.
00012 
00013 Development environment specifics:
00014     IDE: Arduino 1.6
00015     Hardware Platform: Arduino Uno
00016     LSM9DS1 Breakout Version: 1.0
00017 
00018 This code is beerware; if you see me (or any other SparkFun employee) at the
00019 local, and you've found our code helpful, please buy us a round!
00020 
00021 Distributed as-is; no warranty is given.
00022 ******************************************************************************/
00023 
00024 #include "LSM9DS1.h"
00025 #include "LSM9DS1_Registers.h"
00026 #include "LSM9DS1_Types.h"
00027 //#include <Wire.h> // Wire library is used for I2C
00028 //#include <SPI.h>  // SPI library is used for...SPI.
00029 
00030 //#if defined(ARDUINO) && ARDUINO >= 100
00031 //  #include "Arduino.h"
00032 //#else
00033 //  #include "WProgram.h"
00034 //#endif
00035 
00036 #define LSM9DS1_COMMUNICATION_TIMEOUT 1000
00037 
00038 float magSensitivity[4] = {0.00014, 0.00029, 0.00043, 0.00058};
00039 
00040 LSM9DS1::LSM9DS1(PinName sda, PinName scl, uint8_t xgAddr, uint8_t mAddr)
00041     :i2c(sda, scl)
00042 {
00043     init(IMU_MODE_I2C, xgAddr, mAddr); // dont know about 0xD6 or 0x3B
00044 }
00045 /*
00046 LSM9DS1::LSM9DS1()
00047 {
00048     init(IMU_MODE_I2C, LSM9DS1_AG_ADDR(1), LSM9DS1_M_ADDR(1));
00049 }
00050 
00051 LSM9DS1::LSM9DS1(interface_mode interface, uint8_t xgAddr, uint8_t mAddr)
00052 {
00053     init(interface, xgAddr, mAddr);
00054 }
00055 */
00056 
00057 void LSM9DS1::init(interface_mode interface, uint8_t xgAddr, uint8_t mAddr)
00058 {
00059     settings.device.commInterface = interface;
00060     settings.device.agAddress = xgAddr;
00061     settings.device.mAddress = mAddr;
00062 
00063     settings.gyro.enabled = true;
00064     settings.gyro.enableX = true;
00065     settings.gyro.enableY = true;
00066     settings.gyro.enableZ = true;
00067     // gyro scale can be 245, 500, or 2000
00068     settings.gyro.scale = 245;
00069     // gyro sample rate: value between 1-6
00070     // 1 = 14.9    4 = 238
00071     // 2 = 59.5    5 = 476
00072     // 3 = 119     6 = 952
00073     settings.gyro.sampleRate = 6;
00074     // gyro cutoff frequency: value between 0-3
00075     // Actual value of cutoff frequency depends
00076     // on sample rate.
00077     settings.gyro.bandwidth = 0;
00078     settings.gyro.lowPowerEnable = false;
00079     settings.gyro.HPFEnable = false;
00080     // Gyro HPF cutoff frequency: value between 0-9
00081     // Actual value depends on sample rate. Only applies
00082     // if gyroHPFEnable is true.
00083     settings.gyro.HPFCutoff = 0;
00084     settings.gyro.flipX = false;
00085     settings.gyro.flipY = false;
00086     settings.gyro.flipZ = false;
00087     settings.gyro.orientation = 0;
00088     settings.gyro.latchInterrupt = true;
00089 
00090     settings.accel.enabled = true;
00091     settings.accel.enableX = true;
00092     settings.accel.enableY = true;
00093     settings.accel.enableZ = true;
00094     // accel scale can be 2, 4, 8, or 16
00095     settings.accel.scale = 2;
00096     // accel sample rate can be 1-6
00097     // 1 = 10 Hz    4 = 238 Hz
00098     // 2 = 50 Hz    5 = 476 Hz
00099     // 3 = 119 Hz   6 = 952 Hz
00100     settings.accel.sampleRate = 6;
00101     // Accel cutoff freqeuncy can be any value between -1 - 3. 
00102     // -1 = bandwidth determined by sample rate
00103     // 0 = 408 Hz   2 = 105 Hz
00104     // 1 = 211 Hz   3 = 50 Hz
00105     settings.accel.bandwidth = -1;
00106     settings.accel.highResEnable = false;
00107     // accelHighResBandwidth can be any value between 0-3
00108     // LP cutoff is set to a factor of sample rate
00109     // 0 = ODR/50    2 = ODR/9
00110     // 1 = ODR/100   3 = ODR/400
00111     settings.accel.highResBandwidth = 0;
00112 
00113     settings.mag.enabled = true;
00114     // mag scale can be 4, 8, 12, or 16
00115     settings.mag.scale = 4;
00116     // mag data rate can be 0-7
00117     // 0 = 0.625 Hz  4 = 10 Hz
00118     // 1 = 1.25 Hz   5 = 20 Hz
00119     // 2 = 2.5 Hz    6 = 40 Hz
00120     // 3 = 5 Hz      7 = 80 Hz
00121     settings.mag.sampleRate = 7;
00122     settings.mag.tempCompensationEnable = false;
00123     // magPerformance can be any value between 0-3
00124     // 0 = Low power mode      2 = high performance
00125     // 1 = medium performance  3 = ultra-high performance
00126     settings.mag.XYPerformance = 3;
00127     settings.mag.ZPerformance = 3;
00128     settings.mag.lowPowerEnable = false;
00129     // magOperatingMode can be 0-2
00130     // 0 = continuous conversion
00131     // 1 = single-conversion
00132     // 2 = power down
00133     settings.mag.operatingMode = 0;
00134 
00135     settings.temp.enabled = true;
00136     for (int i=0; i<3; i++)
00137     {
00138         gBias[i] = 0;
00139         aBias[i] = 0;
00140         mBias[i] = 0;
00141         gBiasRaw[i] = 0;
00142         aBiasRaw[i] = 0;
00143         mBiasRaw[i] = 0;
00144     }
00145     _autoCalc = false;
00146 }
00147 
00148 
00149 uint16_t LSM9DS1::begin()
00150 {
00151     //! Todo: don't use _xgAddress or _mAddress, duplicating memory
00152     _xgAddress = settings.device.agAddress;
00153     _mAddress = settings.device.mAddress;
00154     
00155     constrainScales();
00156     // Once we have the scale values, we can calculate the resolution
00157     // of each sensor. That's what these functions are for. One for each sensor
00158     calcgRes(); // Calculate DPS / ADC tick, stored in gRes variable
00159     calcmRes(); // Calculate Gs / ADC tick, stored in mRes variable
00160     calcaRes(); // Calculate g / ADC tick, stored in aRes variable
00161     
00162     // Now, initialize our hardware interface.
00163     if (settings.device.commInterface == IMU_MODE_I2C)  // If we're using I2C
00164         initI2C();  // Initialize I2C
00165     else if (settings.device.commInterface == IMU_MODE_SPI)     // else, if we're using SPI
00166         initSPI();  // Initialize SPI
00167         
00168     // To verify communication, we can read from the WHO_AM_I register of
00169     // each device. Store those in a variable so we can return them.
00170     uint8_t mTest = mReadByte(WHO_AM_I_M);      // Read the gyro WHO_AM_I
00171     uint8_t xgTest = xgReadByte(WHO_AM_I_XG);   // Read the accel/mag WHO_AM_I
00172     uint16_t whoAmICombined = (xgTest << 8) | mTest;
00173     
00174     if (whoAmICombined != ((WHO_AM_I_AG_RSP << 8) | WHO_AM_I_M_RSP))
00175         return 0;
00176     
00177     // Gyro initialization stuff:
00178     initGyro(); // This will "turn on" the gyro. Setting up interrupts, etc.
00179     
00180     // Accelerometer initialization stuff:
00181     initAccel(); // "Turn on" all axes of the accel. Set up interrupts, etc.
00182     
00183     // Magnetometer initialization stuff:
00184     initMag(); // "Turn on" all axes of the mag. Set up interrupts, etc.
00185 
00186     // Once everything is initialized, return the WHO_AM_I registers we read:
00187     return whoAmICombined;
00188 }
00189 
00190 void LSM9DS1::initGyro()
00191 {
00192     uint8_t tempRegValue = 0;
00193     
00194     // CTRL_REG1_G (Default value: 0x00)
00195     // [ODR_G2][ODR_G1][ODR_G0][FS_G1][FS_G0][0][BW_G1][BW_G0]
00196     // ODR_G[2:0] - Output data rate selection
00197     // FS_G[1:0] - Gyroscope full-scale selection
00198     // BW_G[1:0] - Gyroscope bandwidth selection
00199     
00200     // To disable gyro, set sample rate bits to 0. We'll only set sample
00201     // rate if the gyro is enabled.
00202     if (settings.gyro.enabled)
00203     {
00204         tempRegValue = (settings.gyro.sampleRate & 0x07) << 5;
00205     }
00206     switch (settings.gyro.scale)
00207     {
00208         case 500:
00209             tempRegValue |= (0x1 << 3);
00210             break;
00211         case 2000:
00212             tempRegValue |= (0x3 << 3);
00213             break;
00214         // Otherwise we'll set it to 245 dps (0x0 << 4)
00215     }
00216     tempRegValue |= (settings.gyro.bandwidth & 0x3);
00217     xgWriteByte(CTRL_REG1_G, tempRegValue);
00218     
00219     // CTRL_REG2_G (Default value: 0x00)
00220     // [0][0][0][0][INT_SEL1][INT_SEL0][OUT_SEL1][OUT_SEL0]
00221     // INT_SEL[1:0] - INT selection configuration
00222     // OUT_SEL[1:0] - Out selection configuration
00223     xgWriteByte(CTRL_REG2_G, 0x00); 
00224     
00225     // CTRL_REG3_G (Default value: 0x00)
00226     // [LP_mode][HP_EN][0][0][HPCF3_G][HPCF2_G][HPCF1_G][HPCF0_G]
00227     // LP_mode - Low-power mode enable (0: disabled, 1: enabled)
00228     // HP_EN - HPF enable (0:disabled, 1: enabled)
00229     // HPCF_G[3:0] - HPF cutoff frequency
00230     tempRegValue = settings.gyro.lowPowerEnable ? (1<<7) : 0;
00231     if (settings.gyro.HPFEnable)
00232     {
00233         tempRegValue |= (1<<6) | (settings.gyro.HPFCutoff & 0x0F);
00234     }
00235     xgWriteByte(CTRL_REG3_G, tempRegValue);
00236     
00237     // CTRL_REG4 (Default value: 0x38)
00238     // [0][0][Zen_G][Yen_G][Xen_G][0][LIR_XL1][4D_XL1]
00239     // Zen_G - Z-axis output enable (0:disable, 1:enable)
00240     // Yen_G - Y-axis output enable (0:disable, 1:enable)
00241     // Xen_G - X-axis output enable (0:disable, 1:enable)
00242     // LIR_XL1 - Latched interrupt (0:not latched, 1:latched)
00243     // 4D_XL1 - 4D option on interrupt (0:6D used, 1:4D used)
00244     tempRegValue = 0;
00245     if (settings.gyro.enableZ) tempRegValue |= (1<<5);
00246     if (settings.gyro.enableY) tempRegValue |= (1<<4);
00247     if (settings.gyro.enableX) tempRegValue |= (1<<3);
00248     if (settings.gyro.latchInterrupt) tempRegValue |= (1<<1);
00249     xgWriteByte(CTRL_REG4, tempRegValue);
00250     
00251     // ORIENT_CFG_G (Default value: 0x00)
00252     // [0][0][SignX_G][SignY_G][SignZ_G][Orient_2][Orient_1][Orient_0]
00253     // SignX_G - Pitch axis (X) angular rate sign (0: positive, 1: negative)
00254     // Orient [2:0] - Directional user orientation selection
00255     tempRegValue = 0;
00256     if (settings.gyro.flipX) tempRegValue |= (1<<5);
00257     if (settings.gyro.flipY) tempRegValue |= (1<<4);
00258     if (settings.gyro.flipZ) tempRegValue |= (1<<3);
00259     xgWriteByte(ORIENT_CFG_G, tempRegValue);
00260 }
00261 
00262 void LSM9DS1::initAccel()
00263 {
00264     uint8_t tempRegValue = 0;
00265     
00266     //  CTRL_REG5_XL (0x1F) (Default value: 0x38)
00267     //  [DEC_1][DEC_0][Zen_XL][Yen_XL][Zen_XL][0][0][0]
00268     //  DEC[0:1] - Decimation of accel data on OUT REG and FIFO.
00269     //      00: None, 01: 2 samples, 10: 4 samples 11: 8 samples
00270     //  Zen_XL - Z-axis output enabled
00271     //  Yen_XL - Y-axis output enabled
00272     //  Xen_XL - X-axis output enabled
00273     if (settings.accel.enableZ) tempRegValue |= (1<<5);
00274     if (settings.accel.enableY) tempRegValue |= (1<<4);
00275     if (settings.accel.enableX) tempRegValue |= (1<<3);
00276     
00277     xgWriteByte(CTRL_REG5_XL, tempRegValue);
00278     
00279     // CTRL_REG6_XL (0x20) (Default value: 0x00)
00280     // [ODR_XL2][ODR_XL1][ODR_XL0][FS1_XL][FS0_XL][BW_SCAL_ODR][BW_XL1][BW_XL0]
00281     // ODR_XL[2:0] - Output data rate & power mode selection
00282     // FS_XL[1:0] - Full-scale selection
00283     // BW_SCAL_ODR - Bandwidth selection
00284     // BW_XL[1:0] - Anti-aliasing filter bandwidth selection
00285     tempRegValue = 0;
00286     // To disable the accel, set the sampleRate bits to 0.
00287     if (settings.accel.enabled)
00288     {
00289         tempRegValue |= (settings.accel.sampleRate & 0x07) << 5;
00290     }
00291     switch (settings.accel.scale)
00292     {
00293         case 4:
00294             tempRegValue |= (0x2 << 3);
00295             break;
00296         case 8:
00297             tempRegValue |= (0x3 << 3);
00298             break;
00299         case 16:
00300             tempRegValue |= (0x1 << 3);
00301             break;
00302         // Otherwise it'll be set to 2g (0x0 << 3)
00303     }
00304     if (settings.accel.bandwidth >= 0)
00305     {
00306         tempRegValue |= (1<<2); // Set BW_SCAL_ODR
00307         tempRegValue |= (settings.accel.bandwidth & 0x03);
00308     }
00309     xgWriteByte(CTRL_REG6_XL, tempRegValue);
00310     
00311     // CTRL_REG7_XL (0x21) (Default value: 0x00)
00312     // [HR][DCF1][DCF0][0][0][FDS][0][HPIS1]
00313     // HR - High resolution mode (0: disable, 1: enable)
00314     // DCF[1:0] - Digital filter cutoff frequency
00315     // FDS - Filtered data selection
00316     // HPIS1 - HPF enabled for interrupt function
00317     tempRegValue = 0;
00318     if (settings.accel.highResEnable)
00319     {
00320         tempRegValue |= (1<<7); // Set HR bit
00321         tempRegValue |= (settings.accel.highResBandwidth & 0x3) << 5;
00322     }
00323     xgWriteByte(CTRL_REG7_XL, tempRegValue);
00324 }
00325 
00326 // This is a function that uses the FIFO to accumulate sample of accelerometer and gyro data, average
00327 // them, scales them to  gs and deg/s, respectively, and then passes the biases to the main sketch
00328 // for subtraction from all subsequent data. There are no gyro and accelerometer bias registers to store
00329 // the data as there are in the ADXL345, a precursor to the LSM9DS0, or the MPU-9150, so we have to
00330 // subtract the biases ourselves. This results in a more accurate measurement in general and can
00331 // remove errors due to imprecise or varying initial placement. Calibration of sensor data in this manner
00332 // is good practice.
00333 void LSM9DS1::calibrate(bool autoCalc)
00334 {  
00335     uint8_t data[6] = {0, 0, 0, 0, 0, 0};
00336     uint8_t samples = 0;
00337     int ii;
00338     int32_t aBiasRawTemp[3] = {0, 0, 0};
00339     int32_t gBiasRawTemp[3] = {0, 0, 0};
00340     
00341     // Turn on FIFO and set threshold to 32 samples
00342     enableFIFO(true);
00343     setFIFO(FIFO_THS, 0x1F);
00344     while (samples < 0x1F)
00345     {
00346         samples = (xgReadByte(FIFO_SRC) & 0x3F); // Read number of stored samples
00347     }
00348     for(ii = 0; ii < samples ; ii++) 
00349     {   // Read the gyro data stored in the FIFO
00350         readGyro();
00351         gBiasRawTemp[0] += gx;
00352         gBiasRawTemp[1] += gy;
00353         gBiasRawTemp[2] += gz;
00354         readAccel();
00355         aBiasRawTemp[0] += ax;
00356         aBiasRawTemp[1] += ay;
00357         aBiasRawTemp[2] += az - (int16_t)(1./aRes); // Assumes sensor facing up!
00358     }  
00359     for (ii = 0; ii < 3; ii++)
00360     {
00361         gBiasRaw[ii] = gBiasRawTemp[ii] / samples;
00362         gBias[ii] = calcGyro(gBiasRaw[ii]);
00363         aBiasRaw[ii] = aBiasRawTemp[ii] / samples;
00364         aBias[ii] = calcAccel(aBiasRaw[ii]);
00365     }
00366     
00367     enableFIFO(false);
00368     setFIFO(FIFO_OFF, 0x00);
00369     
00370     if (autoCalc) _autoCalc = true;
00371 }
00372 
00373 void LSM9DS1::calibrateMag(bool loadIn)
00374 {
00375     int i, j;
00376     int16_t magMin[3] = {0, 0, 0};
00377     int16_t magMax[3] = {0, 0, 0}; // The road warrior
00378     
00379     for (i=0; i<128; i++)
00380     {
00381         while (!magAvailable())
00382             ;
00383         readMag();
00384         int16_t magTemp[3] = {0, 0, 0};
00385         magTemp[0] = mx;        
00386         magTemp[1] = my;
00387         magTemp[2] = mz;
00388         for (j = 0; j < 3; j++)
00389         {
00390             if (magTemp[j] > magMax[j]) magMax[j] = magTemp[j];
00391             if (magTemp[j] < magMin[j]) magMin[j] = magTemp[j];
00392         }
00393     }
00394     for (j = 0; j < 3; j++)
00395     {
00396         mBiasRaw[j] = (magMax[j] + magMin[j]) / 2;
00397         mBias[j] = calcMag(mBiasRaw[j]);
00398         if (loadIn)
00399             magOffset(j, mBiasRaw[j]);
00400     }
00401     
00402 }
00403 void LSM9DS1::magOffset(uint8_t axis, int16_t offset)
00404 {
00405     if (axis > 2)
00406         return;
00407     uint8_t msb, lsb;
00408     msb = (offset & 0xFF00) >> 8;
00409     lsb = offset & 0x00FF;
00410     mWriteByte(OFFSET_X_REG_L_M + (2 * axis), lsb);
00411     mWriteByte(OFFSET_X_REG_H_M + (2 * axis), msb);
00412 }
00413 
00414 void LSM9DS1::initMag()
00415 {
00416     uint8_t tempRegValue = 0;
00417     
00418     // CTRL_REG1_M (Default value: 0x10)
00419     // [TEMP_COMP][OM1][OM0][DO2][DO1][DO0][0][ST]
00420     // TEMP_COMP - Temperature compensation
00421     // OM[1:0] - X & Y axes op mode selection
00422     //  00:low-power, 01:medium performance
00423     //  10: high performance, 11:ultra-high performance
00424     // DO[2:0] - Output data rate selection
00425     // ST - Self-test enable
00426     if (settings.mag.tempCompensationEnable) tempRegValue |= (1<<7);
00427     tempRegValue |= (settings.mag.XYPerformance & 0x3) << 5;
00428     tempRegValue |= (settings.mag.sampleRate & 0x7) << 2;
00429     mWriteByte(CTRL_REG1_M, tempRegValue);
00430     
00431     // CTRL_REG2_M (Default value 0x00)
00432     // [0][FS1][FS0][0][REBOOT][SOFT_RST][0][0]
00433     // FS[1:0] - Full-scale configuration
00434     // REBOOT - Reboot memory content (0:normal, 1:reboot)
00435     // SOFT_RST - Reset config and user registers (0:default, 1:reset)
00436     tempRegValue = 0;
00437     switch (settings.mag.scale)
00438     {
00439     case 8:
00440         tempRegValue |= (0x1 << 5);
00441         break;
00442     case 12:
00443         tempRegValue |= (0x2 << 5);
00444         break;
00445     case 16:
00446         tempRegValue |= (0x3 << 5);
00447         break;
00448     // Otherwise we'll default to 4 gauss (00)
00449     }
00450     mWriteByte(CTRL_REG2_M, tempRegValue); // +/-4Gauss
00451     
00452     // CTRL_REG3_M (Default value: 0x03)
00453     // [I2C_DISABLE][0][LP][0][0][SIM][MD1][MD0]
00454     // I2C_DISABLE - Disable I2C interace (0:enable, 1:disable)
00455     // LP - Low-power mode cofiguration (1:enable)
00456     // SIM - SPI mode selection (0:write-only, 1:read/write enable)
00457     // MD[1:0] - Operating mode
00458     //  00:continuous conversion, 01:single-conversion,
00459     //  10,11: Power-down
00460     tempRegValue = 0;
00461     if (settings.mag.lowPowerEnable) tempRegValue |= (1<<5);
00462     tempRegValue |= (settings.mag.operatingMode & 0x3);
00463     mWriteByte(CTRL_REG3_M, tempRegValue); // Continuous conversion mode
00464     
00465     // CTRL_REG4_M (Default value: 0x00)
00466     // [0][0][0][0][OMZ1][OMZ0][BLE][0]
00467     // OMZ[1:0] - Z-axis operative mode selection
00468     //  00:low-power mode, 01:medium performance
00469     //  10:high performance, 10:ultra-high performance
00470     // BLE - Big/little endian data
00471     tempRegValue = 0;
00472     tempRegValue = (settings.mag.ZPerformance & 0x3) << 2;
00473     mWriteByte(CTRL_REG4_M, tempRegValue);
00474     
00475     // CTRL_REG5_M (Default value: 0x00)
00476     // [0][BDU][0][0][0][0][0][0]
00477     // BDU - Block data update for magnetic data
00478     //  0:continuous, 1:not updated until MSB/LSB are read
00479     tempRegValue = 0;
00480     mWriteByte(CTRL_REG5_M, tempRegValue);
00481 }
00482 
00483 uint8_t LSM9DS1::accelAvailable()
00484 {
00485     uint8_t status = xgReadByte(STATUS_REG_1);
00486     
00487     return (status & (1<<0));
00488 }
00489 
00490 uint8_t LSM9DS1::gyroAvailable()
00491 {
00492     uint8_t status = xgReadByte(STATUS_REG_1);
00493     
00494     return ((status & (1<<1)) >> 1);
00495 }
00496 
00497 uint8_t LSM9DS1::tempAvailable()
00498 {
00499     uint8_t status = xgReadByte(STATUS_REG_1);
00500     
00501     return ((status & (1<<2)) >> 2);
00502 }
00503 
00504 uint8_t LSM9DS1::magAvailable(lsm9ds1_axis axis)
00505 {
00506     uint8_t status;
00507     status = mReadByte(STATUS_REG_M);
00508     
00509     return ((status & (1<<axis)) >> axis);
00510 }
00511 
00512 void LSM9DS1::readAccel()
00513 {
00514     uint8_t temp[6]; // We'll read six bytes from the accelerometer into temp   
00515     xgReadBytes(OUT_X_L_XL, temp, 6); // Read 6 bytes, beginning at OUT_X_L_XL
00516     ax = (temp[1] << 8) | temp[0]; // Store x-axis values into ax
00517     ay = (temp[3] << 8) | temp[2]; // Store y-axis values into ay
00518     az = (temp[5] << 8) | temp[4]; // Store z-axis values into az
00519     if (_autoCalc)
00520     {
00521         ax -= aBiasRaw[X_AXIS];
00522         ay -= aBiasRaw[Y_AXIS];
00523         az -= aBiasRaw[Z_AXIS];
00524     }
00525 }
00526 
00527 int16_t LSM9DS1::readAccel(lsm9ds1_axis axis)
00528 {
00529     uint8_t temp[2];
00530     int16_t value;
00531     xgReadBytes(OUT_X_L_XL + (2 * axis), temp, 2);
00532     value = (temp[1] << 8) | temp[0];
00533     
00534     if (_autoCalc)
00535         value -= aBiasRaw[axis];
00536     
00537     return value;
00538 }
00539 
00540 void LSM9DS1::readMag()
00541 {
00542     uint8_t temp[6]; // We'll read six bytes from the mag into temp 
00543     mReadBytes(OUT_X_L_M, temp, 6); // Read 6 bytes, beginning at OUT_X_L_M
00544     mx = (temp[1] << 8) | temp[0]; // Store x-axis values into mx
00545     my = (temp[3] << 8) | temp[2]; // Store y-axis values into my
00546     mz = (temp[5] << 8) | temp[4]; // Store z-axis values into mz
00547 }
00548 
00549 int16_t LSM9DS1::readMag(lsm9ds1_axis axis)
00550 {
00551     uint8_t temp[2];
00552     mReadBytes(OUT_X_L_M + (2 * axis), temp, 2);
00553     return (temp[1] << 8) | temp[0];
00554 }
00555 
00556 void LSM9DS1::readTemp()
00557 {
00558     uint8_t temp[2]; // We'll read two bytes from the temperature sensor into temp  
00559     xgReadBytes(OUT_TEMP_L, temp, 2); // Read 2 bytes, beginning at OUT_TEMP_L
00560     temperature = ((int16_t)temp[1] << 8) | temp[0];
00561 }
00562 
00563 void LSM9DS1::readGyro()
00564 {
00565     uint8_t temp[6]; // We'll read six bytes from the gyro into temp
00566     xgReadBytes(OUT_X_L_G, temp, 6); // Read 6 bytes, beginning at OUT_X_L_G
00567     gx = (temp[1] << 8) | temp[0]; // Store x-axis values into gx
00568     gy = (temp[3] << 8) | temp[2]; // Store y-axis values into gy
00569     gz = (temp[5] << 8) | temp[4]; // Store z-axis values into gz
00570     if (_autoCalc)
00571     {
00572         gx -= gBiasRaw[X_AXIS];
00573         gy -= gBiasRaw[Y_AXIS];
00574         gz -= gBiasRaw[Z_AXIS];
00575     }
00576 }
00577 
00578 int16_t LSM9DS1::readGyro(lsm9ds1_axis axis)
00579 {
00580     uint8_t temp[2];
00581     int16_t value;
00582     
00583     xgReadBytes(OUT_X_L_G + (2 * axis), temp, 2);
00584     
00585     value = (temp[1] << 8) | temp[0];
00586     
00587     if (_autoCalc)
00588         value -= gBiasRaw[axis];
00589     
00590     return value;
00591 }
00592 
00593 float LSM9DS1::calcGyro(int16_t gyro)
00594 {
00595     // Return the gyro raw reading times our pre-calculated DPS / (ADC tick):
00596     return gRes * gyro; 
00597 }
00598 
00599 float LSM9DS1::calcAccel(int16_t accel)
00600 {
00601     // Return the accel raw reading times our pre-calculated g's / (ADC tick):
00602     return aRes * accel;
00603 }
00604 
00605 float LSM9DS1::calcMag(int16_t mag)
00606 {
00607     // Return the mag raw reading times our pre-calculated Gs / (ADC tick):
00608     return mRes * mag;
00609 }
00610 
00611 void LSM9DS1::setGyroScale(uint16_t gScl)
00612 {
00613     // Read current value of CTRL_REG1_G:
00614     uint8_t ctrl1RegValue = xgReadByte(CTRL_REG1_G);
00615     // Mask out scale bits (3 & 4):
00616     ctrl1RegValue &= 0xE7;
00617     switch (gScl)
00618     {
00619         case 500:
00620             ctrl1RegValue |= (0x1 << 3);
00621             settings.gyro.scale = 500;
00622             break;
00623         case 2000:
00624             ctrl1RegValue |= (0x3 << 3);
00625             settings.gyro.scale = 2000;
00626             break;
00627         default: // Otherwise we'll set it to 245 dps (0x0 << 4)
00628             settings.gyro.scale = 245;
00629             break;
00630     }
00631     xgWriteByte(CTRL_REG1_G, ctrl1RegValue);
00632     
00633     calcgRes(); 
00634 }
00635 
00636 void LSM9DS1::setAccelScale(uint8_t aScl)
00637 {
00638     // We need to preserve the other bytes in CTRL_REG6_XL. So, first read it:
00639     uint8_t tempRegValue = xgReadByte(CTRL_REG6_XL);
00640     // Mask out accel scale bits:
00641     tempRegValue &= 0xE7;
00642     
00643     switch (aScl)
00644     {
00645         case 4:
00646             tempRegValue |= (0x2 << 3);
00647             settings.accel.scale = 4;
00648             break;
00649         case 8:
00650             tempRegValue |= (0x3 << 3);
00651             settings.accel.scale = 8;
00652             break;
00653         case 16:
00654             tempRegValue |= (0x1 << 3);
00655             settings.accel.scale = 16;
00656             break;
00657         default: // Otherwise it'll be set to 2g (0x0 << 3)
00658             settings.accel.scale = 2;
00659             break;
00660     }
00661     xgWriteByte(CTRL_REG6_XL, tempRegValue);
00662     
00663     // Then calculate a new aRes, which relies on aScale being set correctly:
00664     calcaRes();
00665 }
00666 
00667 void LSM9DS1::setMagScale(uint8_t mScl)
00668 {
00669     // We need to preserve the other bytes in CTRL_REG6_XM. So, first read it:
00670     uint8_t temp = mReadByte(CTRL_REG2_M);
00671     // Then mask out the mag scale bits:
00672     temp &= 0xFF^(0x3 << 5);
00673     
00674     switch (mScl)
00675     {
00676     case 8:
00677         temp |= (0x1 << 5);
00678         settings.mag.scale = 8;
00679         break;
00680     case 12:
00681         temp |= (0x2 << 5);
00682         settings.mag.scale = 12;
00683         break;
00684     case 16:
00685         temp |= (0x3 << 5);
00686         settings.mag.scale = 16;
00687         break;
00688     default: // Otherwise we'll default to 4 gauss (00)
00689         settings.mag.scale = 4;
00690         break;
00691     }   
00692     
00693     // And write the new register value back into CTRL_REG6_XM:
00694     mWriteByte(CTRL_REG2_M, temp);
00695     
00696     // We've updated the sensor, but we also need to update our class variables
00697     // First update mScale:
00698     //mScale = mScl;
00699     // Then calculate a new mRes, which relies on mScale being set correctly:
00700     calcmRes();
00701 }
00702 
00703 void LSM9DS1::setGyroODR(uint8_t gRate)
00704 {
00705     // Only do this if gRate is not 0 (which would disable the gyro)
00706     if ((gRate & 0x07) != 0)
00707     {
00708         // We need to preserve the other bytes in CTRL_REG1_G. So, first read it:
00709         uint8_t temp = xgReadByte(CTRL_REG1_G);
00710         // Then mask out the gyro ODR bits:
00711         temp &= 0xFF^(0x7 << 5);
00712         temp |= (gRate & 0x07) << 5;
00713         // Update our settings struct
00714         settings.gyro.sampleRate = gRate & 0x07;
00715         // And write the new register value back into CTRL_REG1_G:
00716         xgWriteByte(CTRL_REG1_G, temp);
00717     }
00718 }
00719 
00720 void LSM9DS1::setAccelODR(uint8_t aRate)
00721 {
00722     // Only do this if aRate is not 0 (which would disable the accel)
00723     if ((aRate & 0x07) != 0)
00724     {
00725         // We need to preserve the other bytes in CTRL_REG1_XM. So, first read it:
00726         uint8_t temp = xgReadByte(CTRL_REG6_XL);
00727         // Then mask out the accel ODR bits:
00728         temp &= 0x1F;
00729         // Then shift in our new ODR bits:
00730         temp |= ((aRate & 0x07) << 5);
00731         settings.accel.sampleRate = aRate & 0x07;
00732         // And write the new register value back into CTRL_REG1_XM:
00733         xgWriteByte(CTRL_REG6_XL, temp);
00734     }
00735 }
00736 
00737 void LSM9DS1::setMagODR(uint8_t mRate)
00738 {
00739     // We need to preserve the other bytes in CTRL_REG5_XM. So, first read it:
00740     uint8_t temp = mReadByte(CTRL_REG1_M);
00741     // Then mask out the mag ODR bits:
00742     temp &= 0xFF^(0x7 << 2);
00743     // Then shift in our new ODR bits:
00744     temp |= ((mRate & 0x07) << 2);
00745     settings.mag.sampleRate = mRate & 0x07;
00746     // And write the new register value back into CTRL_REG5_XM:
00747     mWriteByte(CTRL_REG1_M, temp);
00748 }
00749 
00750 void LSM9DS1::calcgRes()
00751 {
00752     gRes = ((float) settings.gyro.scale) / 32768.0;
00753 }
00754 
00755 void LSM9DS1::calcaRes()
00756 {
00757     aRes = ((float) settings.accel.scale) / 32768.0;
00758 }
00759 
00760 void LSM9DS1::calcmRes()
00761 {
00762     //mRes = ((float) settings.mag.scale) / 32768.0;
00763     switch (settings.mag.scale)
00764     {
00765     case 4:
00766         mRes = magSensitivity[0];
00767         break;
00768     case 8:
00769         mRes = magSensitivity[1];
00770         break;
00771     case 12:
00772         mRes = magSensitivity[2];
00773         break;
00774     case 16:
00775         mRes = magSensitivity[3];
00776         break;
00777     }
00778     
00779 }
00780 
00781 void LSM9DS1::configInt(interrupt_select interrupt, uint8_t generator,
00782                          h_lactive activeLow, pp_od pushPull)
00783 {
00784     // Write to INT1_CTRL or INT2_CTRL. [interupt] should already be one of
00785     // those two values.
00786     // [generator] should be an OR'd list of values from the interrupt_generators enum
00787     xgWriteByte(interrupt, generator);
00788     
00789     // Configure CTRL_REG8
00790     uint8_t temp;
00791     temp = xgReadByte(CTRL_REG8);
00792     
00793     if (activeLow) temp |= (1<<5);
00794     else temp &= ~(1<<5);
00795     
00796     if (pushPull) temp &= ~(1<<4);
00797     else temp |= (1<<4);
00798     
00799     xgWriteByte(CTRL_REG8, temp);
00800 }
00801 
00802 void LSM9DS1::configInactivity(uint8_t duration, uint8_t threshold, bool sleepOn)
00803 {
00804     uint8_t temp = 0;
00805     
00806     temp = threshold & 0x7F;
00807     if (sleepOn) temp |= (1<<7);
00808     xgWriteByte(ACT_THS, temp);
00809     
00810     xgWriteByte(ACT_DUR, duration);
00811 }
00812 
00813 uint8_t LSM9DS1::getInactivity()
00814 {
00815     uint8_t temp = xgReadByte(STATUS_REG_0);
00816     temp &= (0x10);
00817     return temp;
00818 }
00819 
00820 void LSM9DS1::configAccelInt(uint8_t generator, bool andInterrupts)
00821 {
00822     // Use variables from accel_interrupt_generator, OR'd together to create
00823     // the [generator]value.
00824     uint8_t temp = generator;
00825     if (andInterrupts) temp |= 0x80;
00826     xgWriteByte(INT_GEN_CFG_XL, temp);
00827 }
00828 
00829 void LSM9DS1::configAccelThs(uint8_t threshold, lsm9ds1_axis axis, uint8_t duration, bool wait)
00830 {
00831     // Write threshold value to INT_GEN_THS_?_XL.
00832     // axis will be 0, 1, or 2 (x, y, z respectively)
00833     xgWriteByte(INT_GEN_THS_X_XL + axis, threshold);
00834     
00835     // Write duration and wait to INT_GEN_DUR_XL
00836     uint8_t temp;
00837     temp = (duration & 0x7F);
00838     if (wait) temp |= 0x80;
00839     xgWriteByte(INT_GEN_DUR_XL, temp);
00840 }
00841 
00842 uint8_t LSM9DS1::getAccelIntSrc()
00843 {
00844     uint8_t intSrc = xgReadByte(INT_GEN_SRC_XL);
00845     
00846     // Check if the IA_XL (interrupt active) bit is set
00847     if (intSrc & (1<<6))
00848     {
00849         return (intSrc & 0x3F);
00850     }
00851     
00852     return 0;
00853 }
00854 
00855 void LSM9DS1::configGyroInt(uint8_t generator, bool aoi, bool latch)
00856 {
00857     // Use variables from accel_interrupt_generator, OR'd together to create
00858     // the [generator]value.
00859     uint8_t temp = generator;
00860     if (aoi) temp |= 0x80;
00861     if (latch) temp |= 0x40;
00862     xgWriteByte(INT_GEN_CFG_G, temp);
00863 }
00864 
00865 void LSM9DS1::configGyroThs(int16_t threshold, lsm9ds1_axis axis, uint8_t duration, bool wait)
00866 {
00867     uint8_t buffer[2];
00868     buffer[0] = (threshold & 0x7F00) >> 8;
00869     buffer[1] = (threshold & 0x00FF);
00870     // Write threshold value to INT_GEN_THS_?H_G and  INT_GEN_THS_?L_G.
00871     // axis will be 0, 1, or 2 (x, y, z respectively)
00872     xgWriteByte(INT_GEN_THS_XH_G + (axis * 2), buffer[0]);
00873     xgWriteByte(INT_GEN_THS_XH_G + 1 + (axis * 2), buffer[1]);
00874     
00875     // Write duration and wait to INT_GEN_DUR_XL
00876     uint8_t temp;
00877     temp = (duration & 0x7F);
00878     if (wait) temp |= 0x80;
00879     xgWriteByte(INT_GEN_DUR_G, temp);
00880 }
00881 
00882 uint8_t LSM9DS1::getGyroIntSrc()
00883 {
00884     uint8_t intSrc = xgReadByte(INT_GEN_SRC_G);
00885     
00886     // Check if the IA_G (interrupt active) bit is set
00887     if (intSrc & (1<<6))
00888     {
00889         return (intSrc & 0x3F);
00890     }
00891     
00892     return 0;
00893 }
00894 
00895 void LSM9DS1::configMagInt(uint8_t generator, h_lactive activeLow, bool latch)
00896 {
00897     // Mask out non-generator bits (0-4)
00898     uint8_t config = (generator & 0xE0);    
00899     // IEA bit is 0 for active-low, 1 for active-high.
00900     if (activeLow == INT_ACTIVE_HIGH) config |= (1<<2);
00901     // IEL bit is 0 for latched, 1 for not-latched
00902     if (!latch) config |= (1<<1);
00903     // As long as we have at least 1 generator, enable the interrupt
00904     if (generator != 0) config |= (1<<0);
00905     
00906     mWriteByte(INT_CFG_M, config);
00907 }
00908 
00909 void LSM9DS1::configMagThs(uint16_t threshold)
00910 {
00911     // Write high eight bits of [threshold] to INT_THS_H_M
00912     mWriteByte(INT_THS_H_M, uint8_t((threshold & 0x7F00) >> 8));
00913     // Write low eight bits of [threshold] to INT_THS_L_M
00914     mWriteByte(INT_THS_L_M, uint8_t(threshold & 0x00FF));
00915 }
00916 
00917 uint8_t LSM9DS1::getMagIntSrc()
00918 {
00919     uint8_t intSrc = mReadByte(INT_SRC_M);
00920     
00921     // Check if the INT (interrupt active) bit is set
00922     if (intSrc & (1<<0))
00923     {
00924         return (intSrc & 0xFE);
00925     }
00926     
00927     return 0;
00928 }
00929 
00930 void LSM9DS1::sleepGyro(bool enable)
00931 {
00932     uint8_t temp = xgReadByte(CTRL_REG9);
00933     if (enable) temp |= (1<<6);
00934     else temp &= ~(1<<6);
00935     xgWriteByte(CTRL_REG9, temp);
00936 }
00937 
00938 void LSM9DS1::enableFIFO(bool enable)
00939 {
00940     uint8_t temp = xgReadByte(CTRL_REG9);
00941     if (enable) temp |= (1<<1);
00942     else temp &= ~(1<<1);
00943     xgWriteByte(CTRL_REG9, temp);
00944 }
00945 
00946 void LSM9DS1::setFIFO(fifoMode_type fifoMode, uint8_t fifoThs)
00947 {
00948     // Limit threshold - 0x1F (31) is the maximum. If more than that was asked
00949     // limit it to the maximum.
00950     uint8_t threshold = fifoThs <= 0x1F ? fifoThs : 0x1F;
00951     xgWriteByte(FIFO_CTRL, ((fifoMode & 0x7) << 5) | (threshold & 0x1F));
00952 }
00953 
00954 uint8_t LSM9DS1::getFIFOSamples()
00955 {
00956     return (xgReadByte(FIFO_SRC) & 0x3F);
00957 }
00958 
00959 void LSM9DS1::constrainScales()
00960 {
00961     if ((settings.gyro.scale != 245) && (settings.gyro.scale != 500) && 
00962         (settings.gyro.scale != 2000))
00963     {
00964         settings.gyro.scale = 245;
00965     }
00966         
00967     if ((settings.accel.scale != 2) && (settings.accel.scale != 4) &&
00968         (settings.accel.scale != 8) && (settings.accel.scale != 16))
00969     {
00970         settings.accel.scale = 2;
00971     }
00972         
00973     if ((settings.mag.scale != 4) && (settings.mag.scale != 8) &&
00974         (settings.mag.scale != 12) && (settings.mag.scale != 16))
00975     {
00976         settings.mag.scale = 4;
00977     }
00978 }
00979 
00980 void LSM9DS1::xgWriteByte(uint8_t subAddress, uint8_t data)
00981 {
00982     // Whether we're using I2C or SPI, write a byte using the
00983     // gyro-specific I2C address or SPI CS pin.
00984     if (settings.device.commInterface == IMU_MODE_I2C) {
00985         printf("yo");
00986         I2CwriteByte(_xgAddress, subAddress, data);
00987     } else if (settings.device.commInterface == IMU_MODE_SPI) {
00988         SPIwriteByte(_xgAddress, subAddress, data);
00989     }
00990 }
00991 
00992 void LSM9DS1::mWriteByte(uint8_t subAddress, uint8_t data)
00993 {
00994     // Whether we're using I2C or SPI, write a byte using the
00995     // accelerometer-specific I2C address or SPI CS pin.
00996     if (settings.device.commInterface == IMU_MODE_I2C)
00997         return I2CwriteByte(_mAddress, subAddress, data);
00998     else if (settings.device.commInterface == IMU_MODE_SPI)
00999         return SPIwriteByte(_mAddress, subAddress, data);
01000 }
01001 
01002 uint8_t LSM9DS1::xgReadByte(uint8_t subAddress)
01003 {
01004     // Whether we're using I2C or SPI, read a byte using the
01005     // gyro-specific I2C address or SPI CS pin.
01006     if (settings.device.commInterface == IMU_MODE_I2C)
01007         return I2CreadByte(_xgAddress, subAddress);
01008     else if (settings.device.commInterface == IMU_MODE_SPI)
01009         return SPIreadByte(_xgAddress, subAddress);
01010 }
01011 
01012 void LSM9DS1::xgReadBytes(uint8_t subAddress, uint8_t * dest, uint8_t count)
01013 {
01014     // Whether we're using I2C or SPI, read multiple bytes using the
01015     // gyro-specific I2C address or SPI CS pin.
01016     if (settings.device.commInterface == IMU_MODE_I2C) {
01017         I2CreadBytes(_xgAddress, subAddress, dest, count);
01018     } else if (settings.device.commInterface == IMU_MODE_SPI) {
01019         SPIreadBytes(_xgAddress, subAddress, dest, count);
01020     }
01021 }
01022 
01023 uint8_t LSM9DS1::mReadByte(uint8_t subAddress)
01024 {
01025     // Whether we're using I2C or SPI, read a byte using the
01026     // accelerometer-specific I2C address or SPI CS pin.
01027     if (settings.device.commInterface == IMU_MODE_I2C)
01028         return I2CreadByte(_mAddress, subAddress);
01029     else if (settings.device.commInterface == IMU_MODE_SPI)
01030         return SPIreadByte(_mAddress, subAddress);
01031 }
01032 
01033 void LSM9DS1::mReadBytes(uint8_t subAddress, uint8_t * dest, uint8_t count)
01034 {
01035     // Whether we're using I2C or SPI, read multiple bytes using the
01036     // accelerometer-specific I2C address or SPI CS pin.
01037     if (settings.device.commInterface == IMU_MODE_I2C)
01038         I2CreadBytes(_mAddress, subAddress, dest, count);
01039     else if (settings.device.commInterface == IMU_MODE_SPI)
01040         SPIreadBytes(_mAddress, subAddress, dest, count);
01041 }
01042 
01043 void LSM9DS1::initSPI()
01044 {
01045     /* 
01046     pinMode(_xgAddress, OUTPUT);
01047     digitalWrite(_xgAddress, HIGH);
01048     pinMode(_mAddress, OUTPUT);
01049     digitalWrite(_mAddress, HIGH);
01050     
01051     SPI.begin();
01052     // Maximum SPI frequency is 10MHz, could divide by 2 here:
01053     SPI.setClockDivider(SPI_CLOCK_DIV2);
01054     // Data is read and written MSb first.
01055     SPI.setBitOrder(MSBFIRST);
01056     // Data is captured on rising edge of clock (CPHA = 0)
01057     // Base value of the clock is HIGH (CPOL = 1)
01058     SPI.setDataMode(SPI_MODE0);
01059     */
01060 }
01061 
01062 void LSM9DS1::SPIwriteByte(uint8_t csPin, uint8_t subAddress, uint8_t data)
01063 {
01064     /*
01065     digitalWrite(csPin, LOW); // Initiate communication
01066     
01067     // If write, bit 0 (MSB) should be 0
01068     // If single write, bit 1 should be 0
01069     SPI.transfer(subAddress & 0x3F); // Send Address
01070     SPI.transfer(data); // Send data
01071     
01072     digitalWrite(csPin, HIGH); // Close communication
01073     */
01074 }
01075 
01076 uint8_t LSM9DS1::SPIreadByte(uint8_t csPin, uint8_t subAddress)
01077 {
01078     uint8_t temp;
01079     // Use the multiple read function to read 1 byte. 
01080     // Value is returned to `temp`.
01081     SPIreadBytes(csPin, subAddress, &temp, 1);
01082     return temp;
01083 }
01084 
01085 void LSM9DS1::SPIreadBytes(uint8_t csPin, uint8_t subAddress,
01086                             uint8_t * dest, uint8_t count)
01087 {
01088     // To indicate a read, set bit 0 (msb) of first byte to 1
01089     uint8_t rAddress = 0x80 | (subAddress & 0x3F);
01090     // Mag SPI port is different. If we're reading multiple bytes, 
01091     // set bit 1 to 1. The remaining six bytes are the address to be read
01092     if ((csPin == _mAddress) && count > 1)
01093         rAddress |= 0x40;
01094     
01095     /* 
01096     digitalWrite(csPin, LOW); // Initiate communication
01097     SPI.transfer(rAddress);
01098     for (int i=0; i<count; i++)
01099     {
01100         dest[i] = SPI.transfer(0x00); // Read into destination array
01101     }
01102     digitalWrite(csPin, HIGH); // Close communication
01103     */
01104 }
01105 
01106 void LSM9DS1::initI2C()
01107 {
01108     /* 
01109     Wire.begin();   // Initialize I2C library
01110     */
01111     
01112     //already initialized in constructor!
01113 }
01114 
01115 // Wire.h read and write protocols
01116 void LSM9DS1::I2CwriteByte(uint8_t address, uint8_t subAddress, uint8_t data)
01117 {
01118     /* 
01119     Wire.beginTransmission(address);  // Initialize the Tx buffer
01120     Wire.write(subAddress);           // Put slave register address in Tx buffer
01121     Wire.write(data);                 // Put data in Tx buffer
01122     Wire.endTransmission();           // Send the Tx buffer
01123     */
01124     char temp_data[2] = {subAddress, data};
01125     i2c.write(address, temp_data, 2);
01126 }
01127 
01128 uint8_t LSM9DS1::I2CreadByte(uint8_t address, uint8_t subAddress)
01129 {
01130     /* 
01131     int timeout = LSM9DS1_COMMUNICATION_TIMEOUT;
01132     uint8_t data; // `data` will store the register data    
01133     
01134     Wire.beginTransmission(address);         // Initialize the Tx buffer
01135     Wire.write(subAddress);                  // Put slave register address in Tx buffer
01136     Wire.endTransmission(true);             // Send the Tx buffer, but send a restart to keep connection alive
01137     Wire.requestFrom(address, (uint8_t) 1);  // Read one byte from slave register address 
01138     while ((Wire.available() < 1) && (timeout-- > 0))
01139         delay(1);
01140     
01141     if (timeout <= 0)
01142         return 255; //! Bad! 255 will be misinterpreted as a good value.
01143     
01144     data = Wire.read();                      // Fill Rx buffer with result
01145     return data;                             // Return data read from slave register
01146     */
01147     char data;
01148     char temp[1] = {subAddress};
01149     
01150     i2c.write(address, temp, 1);
01151     //i2c.write(address & 0xFE);
01152     temp[1] = 0x00;
01153     i2c.write(address, temp, 1);
01154     //i2c.write( address | 0x01);
01155     int a = i2c.read(address, &data, 1);
01156     return data;
01157 }
01158 
01159 uint8_t LSM9DS1::I2CreadBytes(uint8_t address, uint8_t subAddress, uint8_t * dest, uint8_t count)
01160 {  
01161     /* 
01162     int timeout = LSM9DS1_COMMUNICATION_TIMEOUT;
01163     Wire.beginTransmission(address);   // Initialize the Tx buffer
01164     // Next send the register to be read. OR with 0x80 to indicate multi-read.
01165     Wire.write(subAddress | 0x80);     // Put slave register address in Tx buffer
01166 
01167     Wire.endTransmission(true);             // Send the Tx buffer, but send a restart to keep connection alive
01168     uint8_t i = 0;
01169     Wire.requestFrom(address, count);  // Read bytes from slave register address 
01170     while ((Wire.available() < count) && (timeout-- > 0))
01171         delay(1);
01172     if (timeout <= 0)
01173         return -1;
01174     
01175     for (int i=0; i<count;)
01176     {
01177         if (Wire.available())
01178         {
01179             dest[i++] = Wire.read();
01180         }
01181     }
01182     return count;
01183     */
01184     int i;
01185     char temp_dest[count];
01186     char temp[1] = {subAddress};
01187     i2c.write(address, temp, 1);
01188     i2c.read(address, temp_dest, count);
01189     
01190     //i2c doesn't take uint8_ts, but rather chars so do this nasty af conversion
01191     for (i=0; i < count; i++) {
01192         dest[i] = temp_dest[i];    
01193     }
01194     return count;
01195 }