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 extern Serial pc;
00040 
00041 LSM9DS1::LSM9DS1(PinName sda, PinName scl, uint8_t xgAddr, uint8_t mAddr)
00042     :i2c(sda, scl)
00043 {
00044     init(IMU_MODE_I2C, xgAddr, mAddr); // dont know about 0xD6 or 0x3B
00045 }
00046 /*
00047 LSM9DS1::LSM9DS1()
00048 {
00049     init(IMU_MODE_I2C, LSM9DS1_AG_ADDR(1), LSM9DS1_M_ADDR(1));
00050 }
00051 
00052 LSM9DS1::LSM9DS1(interface_mode interface, uint8_t xgAddr, uint8_t mAddr)
00053 {
00054     init(interface, xgAddr, mAddr);
00055 }
00056 */
00057 
00058 void LSM9DS1::init(interface_mode interface, uint8_t xgAddr, uint8_t mAddr)
00059 {
00060     settings.device.commInterface = interface;
00061     settings.device.agAddress = xgAddr;
00062     settings.device.mAddress = mAddr;
00063 
00064     settings.gyro.enabled = true;
00065     settings.gyro.enableX = true;
00066     settings.gyro.enableY = true;
00067     settings.gyro.enableZ = true;
00068     // gyro scale can be 245, 500, or 2000
00069     settings.gyro.scale = 245;
00070     // gyro sample rate: value between 1-6
00071     // 1 = 14.9    4 = 238
00072     // 2 = 59.5    5 = 476
00073     // 3 = 119     6 = 952
00074     settings.gyro.sampleRate = 6;
00075     // gyro cutoff frequency: value between 0-3
00076     // Actual value of cutoff frequency depends
00077     // on sample rate.
00078     settings.gyro.bandwidth = 0;
00079     settings.gyro.lowPowerEnable = false;
00080     settings.gyro.HPFEnable = false;
00081     // Gyro HPF cutoff frequency: value between 0-9
00082     // Actual value depends on sample rate. Only applies
00083     // if gyroHPFEnable is true.
00084     settings.gyro.HPFCutoff = 0;
00085     settings.gyro.flipX = false;
00086     settings.gyro.flipY = false;
00087     settings.gyro.flipZ = false;
00088     settings.gyro.orientation = 0;
00089     settings.gyro.latchInterrupt = true;
00090 
00091     settings.accel.enabled = true;
00092     settings.accel.enableX = true;
00093     settings.accel.enableY = true;
00094     settings.accel.enableZ = true;
00095     // accel scale can be 2, 4, 8, or 16
00096     settings.accel.scale = 2;
00097     // accel sample rate can be 1-6
00098     // 1 = 10 Hz    4 = 238 Hz
00099     // 2 = 50 Hz    5 = 476 Hz
00100     // 3 = 119 Hz   6 = 952 Hz
00101     settings.accel.sampleRate = 6;
00102     // Accel cutoff freqeuncy can be any value between -1 - 3. 
00103     // -1 = bandwidth determined by sample rate
00104     // 0 = 408 Hz   2 = 105 Hz
00105     // 1 = 211 Hz   3 = 50 Hz
00106     settings.accel.bandwidth = -1;
00107     settings.accel.highResEnable = false;
00108     // accelHighResBandwidth can be any value between 0-3
00109     // LP cutoff is set to a factor of sample rate
00110     // 0 = ODR/50    2 = ODR/9
00111     // 1 = ODR/100   3 = ODR/400
00112     settings.accel.highResBandwidth = 0;
00113 
00114     settings.mag.enabled = true;
00115     // mag scale can be 4, 8, 12, or 16
00116     settings.mag.scale = 4;
00117     // mag data rate can be 0-7
00118     // 0 = 0.625 Hz  4 = 10 Hz
00119     // 1 = 1.25 Hz   5 = 20 Hz
00120     // 2 = 2.5 Hz    6 = 40 Hz
00121     // 3 = 5 Hz      7 = 80 Hz
00122     settings.mag.sampleRate = 7;
00123     settings.mag.tempCompensationEnable = false;
00124     // magPerformance can be any value between 0-3
00125     // 0 = Low power mode      2 = high performance
00126     // 1 = medium performance  3 = ultra-high performance
00127     settings.mag.XYPerformance = 3;
00128     settings.mag.ZPerformance = 3;
00129     settings.mag.lowPowerEnable = false;
00130     // magOperatingMode can be 0-2
00131     // 0 = continuous conversion
00132     // 1 = single-conversion
00133     // 2 = power down
00134     settings.mag.operatingMode = 0;
00135 
00136     settings.temp.enabled = true;
00137     for (int i=0; i<3; i++)
00138     {
00139         gBias[i] = 0;
00140         aBias[i] = 0;
00141         mBias[i] = 0;
00142         gBiasRaw[i] = 0;
00143         aBiasRaw[i] = 0;
00144         mBiasRaw[i] = 0;
00145     }
00146     _autoCalc = false;
00147 }
00148 
00149 
00150 uint16_t LSM9DS1::begin()
00151 {
00152     //! Todo: don't use _xgAddress or _mAddress, duplicating memory
00153     _xgAddress = settings.device.agAddress;
00154     _mAddress = settings.device.mAddress;
00155     
00156     constrainScales();
00157     // Once we have the scale values, we can calculate the resolution
00158     // of each sensor. That's what these functions are for. One for each sensor
00159     calcgRes(); // Calculate DPS / ADC tick, stored in gRes variable
00160     calcmRes(); // Calculate Gs / ADC tick, stored in mRes variable
00161     calcaRes(); // Calculate g / ADC tick, stored in aRes variable
00162     
00163     // Now, initialize our hardware interface.
00164     if (settings.device.commInterface == IMU_MODE_I2C)  // If we're using I2C
00165         initI2C();  // Initialize I2C
00166     else if (settings.device.commInterface == IMU_MODE_SPI)     // else, if we're using SPI
00167         initSPI();  // Initialize SPI
00168         
00169     // To verify communication, we can read from the WHO_AM_I register of
00170     // each device. Store those in a variable so we can return them.
00171     uint8_t mTest = mReadByte(WHO_AM_I_M);      // Read the gyro WHO_AM_I
00172     uint8_t xgTest = xgReadByte(WHO_AM_I_XG);   // Read the accel/mag WHO_AM_I
00173     pc.printf("%x, %x, %x, %x\n\r", mTest, xgTest, _xgAddress, _mAddress);
00174     uint16_t whoAmICombined = (xgTest << 8) | mTest;
00175     
00176     if (whoAmICombined != ((WHO_AM_I_AG_RSP << 8) | WHO_AM_I_M_RSP))
00177         return 0;
00178     
00179     // Gyro initialization stuff:
00180     initGyro(); // This will "turn on" the gyro. Setting up interrupts, etc.
00181     
00182     // Accelerometer initialization stuff:
00183     initAccel(); // "Turn on" all axes of the accel. Set up interrupts, etc.
00184     
00185     // Magnetometer initialization stuff:
00186     initMag(); // "Turn on" all axes of the mag. Set up interrupts, etc.
00187 
00188     // Once everything is initialized, return the WHO_AM_I registers we read:
00189     return whoAmICombined;
00190 }
00191 
00192 void LSM9DS1::initGyro()
00193 {
00194     uint8_t tempRegValue = 0;
00195     
00196     // CTRL_REG1_G (Default value: 0x00)
00197     // [ODR_G2][ODR_G1][ODR_G0][FS_G1][FS_G0][0][BW_G1][BW_G0]
00198     // ODR_G[2:0] - Output data rate selection
00199     // FS_G[1:0] - Gyroscope full-scale selection
00200     // BW_G[1:0] - Gyroscope bandwidth selection
00201     
00202     // To disable gyro, set sample rate bits to 0. We'll only set sample
00203     // rate if the gyro is enabled.
00204     if (settings.gyro.enabled)
00205     {
00206         tempRegValue = (settings.gyro.sampleRate & 0x07) << 5;
00207     }
00208     switch (settings.gyro.scale)
00209     {
00210         case 500:
00211             tempRegValue |= (0x1 << 3);
00212             break;
00213         case 2000:
00214             tempRegValue |= (0x3 << 3);
00215             break;
00216         // Otherwise we'll set it to 245 dps (0x0 << 4)
00217     }
00218     tempRegValue |= (settings.gyro.bandwidth & 0x3);
00219     xgWriteByte(CTRL_REG1_G, tempRegValue);
00220     
00221     // CTRL_REG2_G (Default value: 0x00)
00222     // [0][0][0][0][INT_SEL1][INT_SEL0][OUT_SEL1][OUT_SEL0]
00223     // INT_SEL[1:0] - INT selection configuration
00224     // OUT_SEL[1:0] - Out selection configuration
00225     xgWriteByte(CTRL_REG2_G, 0x00); 
00226     
00227     // CTRL_REG3_G (Default value: 0x00)
00228     // [LP_mode][HP_EN][0][0][HPCF3_G][HPCF2_G][HPCF1_G][HPCF0_G]
00229     // LP_mode - Low-power mode enable (0: disabled, 1: enabled)
00230     // HP_EN - HPF enable (0:disabled, 1: enabled)
00231     // HPCF_G[3:0] - HPF cutoff frequency
00232     tempRegValue = settings.gyro.lowPowerEnable ? (1<<7) : 0;
00233     if (settings.gyro.HPFEnable)
00234     {
00235         tempRegValue |= (1<<6) | (settings.gyro.HPFCutoff & 0x0F);
00236     }
00237     xgWriteByte(CTRL_REG3_G, tempRegValue);
00238     
00239     // CTRL_REG4 (Default value: 0x38)
00240     // [0][0][Zen_G][Yen_G][Xen_G][0][LIR_XL1][4D_XL1]
00241     // Zen_G - Z-axis output enable (0:disable, 1:enable)
00242     // Yen_G - Y-axis output enable (0:disable, 1:enable)
00243     // Xen_G - X-axis output enable (0:disable, 1:enable)
00244     // LIR_XL1 - Latched interrupt (0:not latched, 1:latched)
00245     // 4D_XL1 - 4D option on interrupt (0:6D used, 1:4D used)
00246     tempRegValue = 0;
00247     if (settings.gyro.enableZ) tempRegValue |= (1<<5);
00248     if (settings.gyro.enableY) tempRegValue |= (1<<4);
00249     if (settings.gyro.enableX) tempRegValue |= (1<<3);
00250     if (settings.gyro.latchInterrupt) tempRegValue |= (1<<1);
00251     xgWriteByte(CTRL_REG4, tempRegValue);
00252     
00253     // ORIENT_CFG_G (Default value: 0x00)
00254     // [0][0][SignX_G][SignY_G][SignZ_G][Orient_2][Orient_1][Orient_0]
00255     // SignX_G - Pitch axis (X) angular rate sign (0: positive, 1: negative)
00256     // Orient [2:0] - Directional user orientation selection
00257     tempRegValue = 0;
00258     if (settings.gyro.flipX) tempRegValue |= (1<<5);
00259     if (settings.gyro.flipY) tempRegValue |= (1<<4);
00260     if (settings.gyro.flipZ) tempRegValue |= (1<<3);
00261     xgWriteByte(ORIENT_CFG_G, tempRegValue);
00262 }
00263 
00264 void LSM9DS1::initAccel()
00265 {
00266     uint8_t tempRegValue = 0;
00267     
00268     //  CTRL_REG5_XL (0x1F) (Default value: 0x38)
00269     //  [DEC_1][DEC_0][Zen_XL][Yen_XL][Zen_XL][0][0][0]
00270     //  DEC[0:1] - Decimation of accel data on OUT REG and FIFO.
00271     //      00: None, 01: 2 samples, 10: 4 samples 11: 8 samples
00272     //  Zen_XL - Z-axis output enabled
00273     //  Yen_XL - Y-axis output enabled
00274     //  Xen_XL - X-axis output enabled
00275     if (settings.accel.enableZ) tempRegValue |= (1<<5);
00276     if (settings.accel.enableY) tempRegValue |= (1<<4);
00277     if (settings.accel.enableX) tempRegValue |= (1<<3);
00278     
00279     xgWriteByte(CTRL_REG5_XL, tempRegValue);
00280     
00281     // CTRL_REG6_XL (0x20) (Default value: 0x00)
00282     // [ODR_XL2][ODR_XL1][ODR_XL0][FS1_XL][FS0_XL][BW_SCAL_ODR][BW_XL1][BW_XL0]
00283     // ODR_XL[2:0] - Output data rate & power mode selection
00284     // FS_XL[1:0] - Full-scale selection
00285     // BW_SCAL_ODR - Bandwidth selection
00286     // BW_XL[1:0] - Anti-aliasing filter bandwidth selection
00287     tempRegValue = 0;
00288     // To disable the accel, set the sampleRate bits to 0.
00289     if (settings.accel.enabled)
00290     {
00291         tempRegValue |= (settings.accel.sampleRate & 0x07) << 5;
00292     }
00293     switch (settings.accel.scale)
00294     {
00295         case 4:
00296             tempRegValue |= (0x2 << 3);
00297             break;
00298         case 8:
00299             tempRegValue |= (0x3 << 3);
00300             break;
00301         case 16:
00302             tempRegValue |= (0x1 << 3);
00303             break;
00304         // Otherwise it'll be set to 2g (0x0 << 3)
00305     }
00306     if (settings.accel.bandwidth >= 0)
00307     {
00308         tempRegValue |= (1<<2); // Set BW_SCAL_ODR
00309         tempRegValue |= (settings.accel.bandwidth & 0x03);
00310     }
00311     xgWriteByte(CTRL_REG6_XL, tempRegValue);
00312     
00313     // CTRL_REG7_XL (0x21) (Default value: 0x00)
00314     // [HR][DCF1][DCF0][0][0][FDS][0][HPIS1]
00315     // HR - High resolution mode (0: disable, 1: enable)
00316     // DCF[1:0] - Digital filter cutoff frequency
00317     // FDS - Filtered data selection
00318     // HPIS1 - HPF enabled for interrupt function
00319     tempRegValue = 0;
00320     if (settings.accel.highResEnable)
00321     {
00322         tempRegValue |= (1<<7); // Set HR bit
00323         tempRegValue |= (settings.accel.highResBandwidth & 0x3) << 5;
00324     }
00325     xgWriteByte(CTRL_REG7_XL, tempRegValue);
00326 }
00327 
00328 // This is a function that uses the FIFO to accumulate sample of accelerometer and gyro data, average
00329 // them, scales them to  gs and deg/s, respectively, and then passes the biases to the main sketch
00330 // for subtraction from all subsequent data. There are no gyro and accelerometer bias registers to store
00331 // the data as there are in the ADXL345, a precursor to the LSM9DS0, or the MPU-9150, so we have to
00332 // subtract the biases ourselves. This results in a more accurate measurement in general and can
00333 // remove errors due to imprecise or varying initial placement. Calibration of sensor data in this manner
00334 // is good practice.
00335 void LSM9DS1::calibrate(bool autoCalc)
00336 {  
00337     uint8_t data[6] = {0, 0, 0, 0, 0, 0};
00338     uint8_t samples = 0;
00339     int ii;
00340     int32_t aBiasRawTemp[3] = {0, 0, 0};
00341     int32_t gBiasRawTemp[3] = {0, 0, 0};
00342     
00343     // Turn on FIFO and set threshold to 32 samples
00344     enableFIFO(true);
00345     setFIFO(FIFO_THS, 0x1F);
00346     while (samples < 0x1F)
00347     {
00348         samples = (xgReadByte(FIFO_SRC) & 0x3F); // Read number of stored samples
00349     }
00350     for(ii = 0; ii < samples ; ii++) 
00351     {   // Read the gyro data stored in the FIFO
00352         readGyro();
00353         gBiasRawTemp[0] += gx;
00354         gBiasRawTemp[1] += gy;
00355         gBiasRawTemp[2] += gz;
00356         readAccel();
00357         aBiasRawTemp[0] += ax;
00358         aBiasRawTemp[1] += ay;
00359         aBiasRawTemp[2] += az - (int16_t)(1./aRes); // Assumes sensor facing up!
00360     }  
00361     for (ii = 0; ii < 3; ii++)
00362     {
00363         gBiasRaw[ii] = gBiasRawTemp[ii] / samples;
00364         gBias[ii] = calcGyro(gBiasRaw[ii]);
00365         aBiasRaw[ii] = aBiasRawTemp[ii] / samples;
00366         aBias[ii] = calcAccel(aBiasRaw[ii]);
00367     }
00368     
00369     enableFIFO(false);
00370     setFIFO(FIFO_OFF, 0x00);
00371     
00372     if (autoCalc) _autoCalc = true;
00373 }
00374 
00375 void LSM9DS1::calibrateMag(bool loadIn)
00376 {
00377     int i, j;
00378     int16_t magMin[3] = {0, 0, 0};
00379     int16_t magMax[3] = {0, 0, 0}; // The road warrior
00380     
00381     for (i=0; i<128; i++)
00382     {
00383         while (!magAvailable())
00384             ;
00385         readMag();
00386         int16_t magTemp[3] = {0, 0, 0};
00387         magTemp[0] = mx;        
00388         magTemp[1] = my;
00389         magTemp[2] = mz;
00390         for (j = 0; j < 3; j++)
00391         {
00392             if (magTemp[j] > magMax[j]) magMax[j] = magTemp[j];
00393             if (magTemp[j] < magMin[j]) magMin[j] = magTemp[j];
00394         }
00395     }
00396     for (j = 0; j < 3; j++)
00397     {
00398         mBiasRaw[j] = (magMax[j] + magMin[j]) / 2;
00399         mBias[j] = calcMag(mBiasRaw[j]);
00400         if (loadIn)
00401             magOffset(j, mBiasRaw[j]);
00402     }
00403     
00404 }
00405 void LSM9DS1::magOffset(uint8_t axis, int16_t offset)
00406 {
00407     if (axis > 2)
00408         return;
00409     uint8_t msb, lsb;
00410     msb = (offset & 0xFF00) >> 8;
00411     lsb = offset & 0x00FF;
00412     mWriteByte(OFFSET_X_REG_L_M + (2 * axis), lsb);
00413     mWriteByte(OFFSET_X_REG_H_M + (2 * axis), msb);
00414 }
00415 
00416 void LSM9DS1::initMag()
00417 {
00418     uint8_t tempRegValue = 0;
00419     
00420     // CTRL_REG1_M (Default value: 0x10)
00421     // [TEMP_COMP][OM1][OM0][DO2][DO1][DO0][0][ST]
00422     // TEMP_COMP - Temperature compensation
00423     // OM[1:0] - X & Y axes op mode selection
00424     //  00:low-power, 01:medium performance
00425     //  10: high performance, 11:ultra-high performance
00426     // DO[2:0] - Output data rate selection
00427     // ST - Self-test enable
00428     if (settings.mag.tempCompensationEnable) tempRegValue |= (1<<7);
00429     tempRegValue |= (settings.mag.XYPerformance & 0x3) << 5;
00430     tempRegValue |= (settings.mag.sampleRate & 0x7) << 2;
00431     mWriteByte(CTRL_REG1_M, tempRegValue);
00432     
00433     // CTRL_REG2_M (Default value 0x00)
00434     // [0][FS1][FS0][0][REBOOT][SOFT_RST][0][0]
00435     // FS[1:0] - Full-scale configuration
00436     // REBOOT - Reboot memory content (0:normal, 1:reboot)
00437     // SOFT_RST - Reset config and user registers (0:default, 1:reset)
00438     tempRegValue = 0;
00439     switch (settings.mag.scale)
00440     {
00441     case 8:
00442         tempRegValue |= (0x1 << 5);
00443         break;
00444     case 12:
00445         tempRegValue |= (0x2 << 5);
00446         break;
00447     case 16:
00448         tempRegValue |= (0x3 << 5);
00449         break;
00450     // Otherwise we'll default to 4 gauss (00)
00451     }
00452     mWriteByte(CTRL_REG2_M, tempRegValue); // +/-4Gauss
00453     
00454     // CTRL_REG3_M (Default value: 0x03)
00455     // [I2C_DISABLE][0][LP][0][0][SIM][MD1][MD0]
00456     // I2C_DISABLE - Disable I2C interace (0:enable, 1:disable)
00457     // LP - Low-power mode cofiguration (1:enable)
00458     // SIM - SPI mode selection (0:write-only, 1:read/write enable)
00459     // MD[1:0] - Operating mode
00460     //  00:continuous conversion, 01:single-conversion,
00461     //  10,11: Power-down
00462     tempRegValue = 0;
00463     if (settings.mag.lowPowerEnable) tempRegValue |= (1<<5);
00464     tempRegValue |= (settings.mag.operatingMode & 0x3);
00465     mWriteByte(CTRL_REG3_M, tempRegValue); // Continuous conversion mode
00466     
00467     // CTRL_REG4_M (Default value: 0x00)
00468     // [0][0][0][0][OMZ1][OMZ0][BLE][0]
00469     // OMZ[1:0] - Z-axis operative mode selection
00470     //  00:low-power mode, 01:medium performance
00471     //  10:high performance, 10:ultra-high performance
00472     // BLE - Big/little endian data
00473     tempRegValue = 0;
00474     tempRegValue = (settings.mag.ZPerformance & 0x3) << 2;
00475     mWriteByte(CTRL_REG4_M, tempRegValue);
00476     
00477     // CTRL_REG5_M (Default value: 0x00)
00478     // [0][BDU][0][0][0][0][0][0]
00479     // BDU - Block data update for magnetic data
00480     //  0:continuous, 1:not updated until MSB/LSB are read
00481     tempRegValue = 0;
00482     mWriteByte(CTRL_REG5_M, tempRegValue);
00483 }
00484 
00485 uint8_t LSM9DS1::accelAvailable()
00486 {
00487     uint8_t status = xgReadByte(STATUS_REG_1);
00488     
00489     return (status & (1<<0));
00490 }
00491 
00492 uint8_t LSM9DS1::gyroAvailable()
00493 {
00494     uint8_t status = xgReadByte(STATUS_REG_1);
00495     
00496     return ((status & (1<<1)) >> 1);
00497 }
00498 
00499 uint8_t LSM9DS1::tempAvailable()
00500 {
00501     uint8_t status = xgReadByte(STATUS_REG_1);
00502     
00503     return ((status & (1<<2)) >> 2);
00504 }
00505 
00506 uint8_t LSM9DS1::magAvailable(lsm9ds1_axis axis)
00507 {
00508     uint8_t status;
00509     status = mReadByte(STATUS_REG_M);
00510     
00511     return ((status & (1<<axis)) >> axis);
00512 }
00513 
00514 void LSM9DS1::readAccel()
00515 {
00516     uint8_t temp[6]; // We'll read six bytes from the accelerometer into temp   
00517     xgReadBytes(OUT_X_L_XL, temp, 6); // Read 6 bytes, beginning at OUT_X_L_XL
00518     ax = (temp[1] << 8) | temp[0]; // Store x-axis values into ax
00519     ay = (temp[3] << 8) | temp[2]; // Store y-axis values into ay
00520     az = (temp[5] << 8) | temp[4]; // Store z-axis values into az
00521     if (_autoCalc)
00522     {
00523         ax -= aBiasRaw[X_AXIS];
00524         ay -= aBiasRaw[Y_AXIS];
00525         az -= aBiasRaw[Z_AXIS];
00526     }
00527 }
00528 
00529 int16_t LSM9DS1::readAccel(lsm9ds1_axis axis)
00530 {
00531     uint8_t temp[2];
00532     int16_t value;
00533     xgReadBytes(OUT_X_L_XL + (2 * axis), temp, 2);
00534     value = (temp[1] << 8) | temp[0];
00535     
00536     if (_autoCalc)
00537         value -= aBiasRaw[axis];
00538     
00539     return value;
00540 }
00541 
00542 void LSM9DS1::readMag()
00543 {
00544     uint8_t temp[6]; // We'll read six bytes from the mag into temp 
00545     mReadBytes(OUT_X_L_M, temp, 6); // Read 6 bytes, beginning at OUT_X_L_M
00546     mx = (temp[1] << 8) | temp[0]; // Store x-axis values into mx
00547     my = (temp[3] << 8) | temp[2]; // Store y-axis values into my
00548     mz = (temp[5] << 8) | temp[4]; // Store z-axis values into mz
00549 }
00550 
00551 int16_t LSM9DS1::readMag(lsm9ds1_axis axis)
00552 {
00553     uint8_t temp[2];
00554     mReadBytes(OUT_X_L_M + (2 * axis), temp, 2);
00555     return (temp[1] << 8) | temp[0];
00556 }
00557 
00558 void LSM9DS1::readTemp()
00559 {
00560     uint8_t temp[2]; // We'll read two bytes from the temperature sensor into temp  
00561     xgReadBytes(OUT_TEMP_L, temp, 2); // Read 2 bytes, beginning at OUT_TEMP_L
00562     temperature = ((int16_t)temp[1] << 8) | temp[0];
00563 }
00564 
00565 void LSM9DS1::readGyro()
00566 {
00567     uint8_t temp[6]; // We'll read six bytes from the gyro into temp
00568     xgReadBytes(OUT_X_L_G, temp, 6); // Read 6 bytes, beginning at OUT_X_L_G
00569     gx = (temp[1] << 8) | temp[0]; // Store x-axis values into gx
00570     gy = (temp[3] << 8) | temp[2]; // Store y-axis values into gy
00571     gz = (temp[5] << 8) | temp[4]; // Store z-axis values into gz
00572     if (_autoCalc)
00573     {
00574         gx -= gBiasRaw[X_AXIS];
00575         gy -= gBiasRaw[Y_AXIS];
00576         gz -= gBiasRaw[Z_AXIS];
00577     }
00578 }
00579 
00580 int16_t LSM9DS1::readGyro(lsm9ds1_axis axis)
00581 {
00582     uint8_t temp[2];
00583     int16_t value;
00584     
00585     xgReadBytes(OUT_X_L_G + (2 * axis), temp, 2);
00586     
00587     value = (temp[1] << 8) | temp[0];
00588     
00589     if (_autoCalc)
00590         value -= gBiasRaw[axis];
00591     
00592     return value;
00593 }
00594 
00595 float LSM9DS1::calcGyro(int16_t gyro)
00596 {
00597     // Return the gyro raw reading times our pre-calculated DPS / (ADC tick):
00598     return gRes * gyro; 
00599 }
00600 
00601 float LSM9DS1::calcAccel(int16_t accel)
00602 {
00603     // Return the accel raw reading times our pre-calculated g's / (ADC tick):
00604     return aRes * accel;
00605 }
00606 
00607 float LSM9DS1::calcMag(int16_t mag)
00608 {
00609     // Return the mag raw reading times our pre-calculated Gs / (ADC tick):
00610     return mRes * mag;
00611 }
00612 
00613 void LSM9DS1::setGyroScale(uint16_t gScl)
00614 {
00615     // Read current value of CTRL_REG1_G:
00616     uint8_t ctrl1RegValue = xgReadByte(CTRL_REG1_G);
00617     // Mask out scale bits (3 & 4):
00618     ctrl1RegValue &= 0xE7;
00619     switch (gScl)
00620     {
00621         case 500:
00622             ctrl1RegValue |= (0x1 << 3);
00623             settings.gyro.scale = 500;
00624             break;
00625         case 2000:
00626             ctrl1RegValue |= (0x3 << 3);
00627             settings.gyro.scale = 2000;
00628             break;
00629         default: // Otherwise we'll set it to 245 dps (0x0 << 4)
00630             settings.gyro.scale = 245;
00631             break;
00632     }
00633     xgWriteByte(CTRL_REG1_G, ctrl1RegValue);
00634     
00635     calcgRes(); 
00636 }
00637 
00638 void LSM9DS1::setAccelScale(uint8_t aScl)
00639 {
00640     // We need to preserve the other bytes in CTRL_REG6_XL. So, first read it:
00641     uint8_t tempRegValue = xgReadByte(CTRL_REG6_XL);
00642     // Mask out accel scale bits:
00643     tempRegValue &= 0xE7;
00644     
00645     switch (aScl)
00646     {
00647         case 4:
00648             tempRegValue |= (0x2 << 3);
00649             settings.accel.scale = 4;
00650             break;
00651         case 8:
00652             tempRegValue |= (0x3 << 3);
00653             settings.accel.scale = 8;
00654             break;
00655         case 16:
00656             tempRegValue |= (0x1 << 3);
00657             settings.accel.scale = 16;
00658             break;
00659         default: // Otherwise it'll be set to 2g (0x0 << 3)
00660             settings.accel.scale = 2;
00661             break;
00662     }
00663     xgWriteByte(CTRL_REG6_XL, tempRegValue);
00664     
00665     // Then calculate a new aRes, which relies on aScale being set correctly:
00666     calcaRes();
00667 }
00668 
00669 void LSM9DS1::setMagScale(uint8_t mScl)
00670 {
00671     // We need to preserve the other bytes in CTRL_REG6_XM. So, first read it:
00672     uint8_t temp = mReadByte(CTRL_REG2_M);
00673     // Then mask out the mag scale bits:
00674     temp &= 0xFF^(0x3 << 5);
00675     
00676     switch (mScl)
00677     {
00678     case 8:
00679         temp |= (0x1 << 5);
00680         settings.mag.scale = 8;
00681         break;
00682     case 12:
00683         temp |= (0x2 << 5);
00684         settings.mag.scale = 12;
00685         break;
00686     case 16:
00687         temp |= (0x3 << 5);
00688         settings.mag.scale = 16;
00689         break;
00690     default: // Otherwise we'll default to 4 gauss (00)
00691         settings.mag.scale = 4;
00692         break;
00693     }   
00694     
00695     // And write the new register value back into CTRL_REG6_XM:
00696     mWriteByte(CTRL_REG2_M, temp);
00697     
00698     // We've updated the sensor, but we also need to update our class variables
00699     // First update mScale:
00700     //mScale = mScl;
00701     // Then calculate a new mRes, which relies on mScale being set correctly:
00702     calcmRes();
00703 }
00704 
00705 void LSM9DS1::setGyroODR(uint8_t gRate)
00706 {
00707     // Only do this if gRate is not 0 (which would disable the gyro)
00708     if ((gRate & 0x07) != 0)
00709     {
00710         // We need to preserve the other bytes in CTRL_REG1_G. So, first read it:
00711         uint8_t temp = xgReadByte(CTRL_REG1_G);
00712         // Then mask out the gyro ODR bits:
00713         temp &= 0xFF^(0x7 << 5);
00714         temp |= (gRate & 0x07) << 5;
00715         // Update our settings struct
00716         settings.gyro.sampleRate = gRate & 0x07;
00717         // And write the new register value back into CTRL_REG1_G:
00718         xgWriteByte(CTRL_REG1_G, temp);
00719     }
00720 }
00721 
00722 void LSM9DS1::setAccelODR(uint8_t aRate)
00723 {
00724     // Only do this if aRate is not 0 (which would disable the accel)
00725     if ((aRate & 0x07) != 0)
00726     {
00727         // We need to preserve the other bytes in CTRL_REG1_XM. So, first read it:
00728         uint8_t temp = xgReadByte(CTRL_REG6_XL);
00729         // Then mask out the accel ODR bits:
00730         temp &= 0x1F;
00731         // Then shift in our new ODR bits:
00732         temp |= ((aRate & 0x07) << 5);
00733         settings.accel.sampleRate = aRate & 0x07;
00734         // And write the new register value back into CTRL_REG1_XM:
00735         xgWriteByte(CTRL_REG6_XL, temp);
00736     }
00737 }
00738 
00739 void LSM9DS1::setMagODR(uint8_t mRate)
00740 {
00741     // We need to preserve the other bytes in CTRL_REG5_XM. So, first read it:
00742     uint8_t temp = mReadByte(CTRL_REG1_M);
00743     // Then mask out the mag ODR bits:
00744     temp &= 0xFF^(0x7 << 2);
00745     // Then shift in our new ODR bits:
00746     temp |= ((mRate & 0x07) << 2);
00747     settings.mag.sampleRate = mRate & 0x07;
00748     // And write the new register value back into CTRL_REG5_XM:
00749     mWriteByte(CTRL_REG1_M, temp);
00750 }
00751 
00752 void LSM9DS1::calcgRes()
00753 {
00754     gRes = ((float) settings.gyro.scale) / 32768.0;
00755 }
00756 
00757 void LSM9DS1::calcaRes()
00758 {
00759     aRes = ((float) settings.accel.scale) / 32768.0;
00760 }
00761 
00762 void LSM9DS1::calcmRes()
00763 {
00764     //mRes = ((float) settings.mag.scale) / 32768.0;
00765     switch (settings.mag.scale)
00766     {
00767     case 4:
00768         mRes = magSensitivity[0];
00769         break;
00770     case 8:
00771         mRes = magSensitivity[1];
00772         break;
00773     case 12:
00774         mRes = magSensitivity[2];
00775         break;
00776     case 16:
00777         mRes = magSensitivity[3];
00778         break;
00779     }
00780     
00781 }
00782 
00783 void LSM9DS1::configInt(interrupt_select interrupt, uint8_t generator,
00784                          h_lactive activeLow, pp_od pushPull)
00785 {
00786     // Write to INT1_CTRL or INT2_CTRL. [interupt] should already be one of
00787     // those two values.
00788     // [generator] should be an OR'd list of values from the interrupt_generators enum
00789     xgWriteByte(interrupt, generator);
00790     
00791     // Configure CTRL_REG8
00792     uint8_t temp;
00793     temp = xgReadByte(CTRL_REG8);
00794     
00795     if (activeLow) temp |= (1<<5);
00796     else temp &= ~(1<<5);
00797     
00798     if (pushPull) temp &= ~(1<<4);
00799     else temp |= (1<<4);
00800     
00801     xgWriteByte(CTRL_REG8, temp);
00802 }
00803 
00804 void LSM9DS1::configInactivity(uint8_t duration, uint8_t threshold, bool sleepOn)
00805 {
00806     uint8_t temp = 0;
00807     
00808     temp = threshold & 0x7F;
00809     if (sleepOn) temp |= (1<<7);
00810     xgWriteByte(ACT_THS, temp);
00811     
00812     xgWriteByte(ACT_DUR, duration);
00813 }
00814 
00815 uint8_t LSM9DS1::getInactivity()
00816 {
00817     uint8_t temp = xgReadByte(STATUS_REG_0);
00818     temp &= (0x10);
00819     return temp;
00820 }
00821 
00822 void LSM9DS1::configAccelInt(uint8_t generator, bool andInterrupts)
00823 {
00824     // Use variables from accel_interrupt_generator, OR'd together to create
00825     // the [generator]value.
00826     uint8_t temp = generator;
00827     if (andInterrupts) temp |= 0x80;
00828     xgWriteByte(INT_GEN_CFG_XL, temp);
00829 }
00830 
00831 void LSM9DS1::configAccelThs(uint8_t threshold, lsm9ds1_axis axis, uint8_t duration, bool wait)
00832 {
00833     // Write threshold value to INT_GEN_THS_?_XL.
00834     // axis will be 0, 1, or 2 (x, y, z respectively)
00835     xgWriteByte(INT_GEN_THS_X_XL + axis, threshold);
00836     
00837     // Write duration and wait to INT_GEN_DUR_XL
00838     uint8_t temp;
00839     temp = (duration & 0x7F);
00840     if (wait) temp |= 0x80;
00841     xgWriteByte(INT_GEN_DUR_XL, temp);
00842 }
00843 
00844 uint8_t LSM9DS1::getAccelIntSrc()
00845 {
00846     uint8_t intSrc = xgReadByte(INT_GEN_SRC_XL);
00847     
00848     // Check if the IA_XL (interrupt active) bit is set
00849     if (intSrc & (1<<6))
00850     {
00851         return (intSrc & 0x3F);
00852     }
00853     
00854     return 0;
00855 }
00856 
00857 void LSM9DS1::configGyroInt(uint8_t generator, bool aoi, bool latch)
00858 {
00859     // Use variables from accel_interrupt_generator, OR'd together to create
00860     // the [generator]value.
00861     uint8_t temp = generator;
00862     if (aoi) temp |= 0x80;
00863     if (latch) temp |= 0x40;
00864     xgWriteByte(INT_GEN_CFG_G, temp);
00865 }
00866 
00867 void LSM9DS1::configGyroThs(int16_t threshold, lsm9ds1_axis axis, uint8_t duration, bool wait)
00868 {
00869     uint8_t buffer[2];
00870     buffer[0] = (threshold & 0x7F00) >> 8;
00871     buffer[1] = (threshold & 0x00FF);
00872     // Write threshold value to INT_GEN_THS_?H_G and  INT_GEN_THS_?L_G.
00873     // axis will be 0, 1, or 2 (x, y, z respectively)
00874     xgWriteByte(INT_GEN_THS_XH_G + (axis * 2), buffer[0]);
00875     xgWriteByte(INT_GEN_THS_XH_G + 1 + (axis * 2), buffer[1]);
00876     
00877     // Write duration and wait to INT_GEN_DUR_XL
00878     uint8_t temp;
00879     temp = (duration & 0x7F);
00880     if (wait) temp |= 0x80;
00881     xgWriteByte(INT_GEN_DUR_G, temp);
00882 }
00883 
00884 uint8_t LSM9DS1::getGyroIntSrc()
00885 {
00886     uint8_t intSrc = xgReadByte(INT_GEN_SRC_G);
00887     
00888     // Check if the IA_G (interrupt active) bit is set
00889     if (intSrc & (1<<6))
00890     {
00891         return (intSrc & 0x3F);
00892     }
00893     
00894     return 0;
00895 }
00896 
00897 void LSM9DS1::configMagInt(uint8_t generator, h_lactive activeLow, bool latch)
00898 {
00899     // Mask out non-generator bits (0-4)
00900     uint8_t config = (generator & 0xE0);    
00901     // IEA bit is 0 for active-low, 1 for active-high.
00902     if (activeLow == INT_ACTIVE_HIGH) config |= (1<<2);
00903     // IEL bit is 0 for latched, 1 for not-latched
00904     if (!latch) config |= (1<<1);
00905     // As long as we have at least 1 generator, enable the interrupt
00906     if (generator != 0) config |= (1<<0);
00907     
00908     mWriteByte(INT_CFG_M, config);
00909 }
00910 
00911 void LSM9DS1::configMagThs(uint16_t threshold)
00912 {
00913     // Write high eight bits of [threshold] to INT_THS_H_M
00914     mWriteByte(INT_THS_H_M, uint8_t((threshold & 0x7F00) >> 8));
00915     // Write low eight bits of [threshold] to INT_THS_L_M
00916     mWriteByte(INT_THS_L_M, uint8_t(threshold & 0x00FF));
00917 }
00918 
00919 uint8_t LSM9DS1::getMagIntSrc()
00920 {
00921     uint8_t intSrc = mReadByte(INT_SRC_M);
00922     
00923     // Check if the INT (interrupt active) bit is set
00924     if (intSrc & (1<<0))
00925     {
00926         return (intSrc & 0xFE);
00927     }
00928     
00929     return 0;
00930 }
00931 
00932 void LSM9DS1::sleepGyro(bool enable)
00933 {
00934     uint8_t temp = xgReadByte(CTRL_REG9);
00935     if (enable) temp |= (1<<6);
00936     else temp &= ~(1<<6);
00937     xgWriteByte(CTRL_REG9, temp);
00938 }
00939 
00940 void LSM9DS1::enableFIFO(bool enable)
00941 {
00942     uint8_t temp = xgReadByte(CTRL_REG9);
00943     if (enable) temp |= (1<<1);
00944     else temp &= ~(1<<1);
00945     xgWriteByte(CTRL_REG9, temp);
00946 }
00947 
00948 void LSM9DS1::setFIFO(fifoMode_type fifoMode, uint8_t fifoThs)
00949 {
00950     // Limit threshold - 0x1F (31) is the maximum. If more than that was asked
00951     // limit it to the maximum.
00952     uint8_t threshold = fifoThs <= 0x1F ? fifoThs : 0x1F;
00953     xgWriteByte(FIFO_CTRL, ((fifoMode & 0x7) << 5) | (threshold & 0x1F));
00954 }
00955 
00956 uint8_t LSM9DS1::getFIFOSamples()
00957 {
00958     return (xgReadByte(FIFO_SRC) & 0x3F);
00959 }
00960 
00961 void LSM9DS1::constrainScales()
00962 {
00963     if ((settings.gyro.scale != 245) && (settings.gyro.scale != 500) && 
00964         (settings.gyro.scale != 2000))
00965     {
00966         settings.gyro.scale = 245;
00967     }
00968         
00969     if ((settings.accel.scale != 2) && (settings.accel.scale != 4) &&
00970         (settings.accel.scale != 8) && (settings.accel.scale != 16))
00971     {
00972         settings.accel.scale = 2;
00973     }
00974         
00975     if ((settings.mag.scale != 4) && (settings.mag.scale != 8) &&
00976         (settings.mag.scale != 12) && (settings.mag.scale != 16))
00977     {
00978         settings.mag.scale = 4;
00979     }
00980 }
00981 
00982 void LSM9DS1::xgWriteByte(uint8_t subAddress, uint8_t data)
00983 {
00984     // Whether we're using I2C or SPI, write a byte using the
00985     // gyro-specific I2C address or SPI CS pin.
00986     if (settings.device.commInterface == IMU_MODE_I2C) {
00987         printf("yo");
00988         I2CwriteByte(_xgAddress, subAddress, data);
00989     } else if (settings.device.commInterface == IMU_MODE_SPI) {
00990         SPIwriteByte(_xgAddress, subAddress, data);
00991     }
00992 }
00993 
00994 void LSM9DS1::mWriteByte(uint8_t subAddress, uint8_t data)
00995 {
00996     // Whether we're using I2C or SPI, write a byte using the
00997     // accelerometer-specific I2C address or SPI CS pin.
00998     if (settings.device.commInterface == IMU_MODE_I2C)
00999         return I2CwriteByte(_mAddress, subAddress, data);
01000     else if (settings.device.commInterface == IMU_MODE_SPI)
01001         return SPIwriteByte(_mAddress, subAddress, data);
01002 }
01003 
01004 uint8_t LSM9DS1::xgReadByte(uint8_t subAddress)
01005 {
01006     // Whether we're using I2C or SPI, read a byte using the
01007     // gyro-specific I2C address or SPI CS pin.
01008     if (settings.device.commInterface == IMU_MODE_I2C)
01009         return I2CreadByte(_xgAddress, subAddress);
01010     else if (settings.device.commInterface == IMU_MODE_SPI)
01011         return SPIreadByte(_xgAddress, subAddress);
01012 }
01013 
01014 void LSM9DS1::xgReadBytes(uint8_t subAddress, uint8_t * dest, uint8_t count)
01015 {
01016     // Whether we're using I2C or SPI, read multiple bytes using the
01017     // gyro-specific I2C address or SPI CS pin.
01018     if (settings.device.commInterface == IMU_MODE_I2C) {
01019         I2CreadBytes(_xgAddress, subAddress, dest, count);
01020     } else if (settings.device.commInterface == IMU_MODE_SPI) {
01021         SPIreadBytes(_xgAddress, subAddress, dest, count);
01022     }
01023 }
01024 
01025 uint8_t LSM9DS1::mReadByte(uint8_t subAddress)
01026 {
01027     // Whether we're using I2C or SPI, read a byte using the
01028     // accelerometer-specific I2C address or SPI CS pin.
01029     if (settings.device.commInterface == IMU_MODE_I2C)
01030         return I2CreadByte(_mAddress, subAddress);
01031     else if (settings.device.commInterface == IMU_MODE_SPI)
01032         return SPIreadByte(_mAddress, subAddress);
01033 }
01034 
01035 void LSM9DS1::mReadBytes(uint8_t subAddress, uint8_t * dest, uint8_t count)
01036 {
01037     // Whether we're using I2C or SPI, read multiple bytes using the
01038     // accelerometer-specific I2C address or SPI CS pin.
01039     if (settings.device.commInterface == IMU_MODE_I2C)
01040         I2CreadBytes(_mAddress, subAddress, dest, count);
01041     else if (settings.device.commInterface == IMU_MODE_SPI)
01042         SPIreadBytes(_mAddress, subAddress, dest, count);
01043 }
01044 
01045 void LSM9DS1::initSPI()
01046 {
01047     /* 
01048     pinMode(_xgAddress, OUTPUT);
01049     digitalWrite(_xgAddress, HIGH);
01050     pinMode(_mAddress, OUTPUT);
01051     digitalWrite(_mAddress, HIGH);
01052     
01053     SPI.begin();
01054     // Maximum SPI frequency is 10MHz, could divide by 2 here:
01055     SPI.setClockDivider(SPI_CLOCK_DIV2);
01056     // Data is read and written MSb first.
01057     SPI.setBitOrder(MSBFIRST);
01058     // Data is captured on rising edge of clock (CPHA = 0)
01059     // Base value of the clock is HIGH (CPOL = 1)
01060     SPI.setDataMode(SPI_MODE0);
01061     */
01062 }
01063 
01064 void LSM9DS1::SPIwriteByte(uint8_t csPin, uint8_t subAddress, uint8_t data)
01065 {
01066     /*
01067     digitalWrite(csPin, LOW); // Initiate communication
01068     
01069     // If write, bit 0 (MSB) should be 0
01070     // If single write, bit 1 should be 0
01071     SPI.transfer(subAddress & 0x3F); // Send Address
01072     SPI.transfer(data); // Send data
01073     
01074     digitalWrite(csPin, HIGH); // Close communication
01075     */
01076 }
01077 
01078 uint8_t LSM9DS1::SPIreadByte(uint8_t csPin, uint8_t subAddress)
01079 {
01080     uint8_t temp;
01081     // Use the multiple read function to read 1 byte. 
01082     // Value is returned to `temp`.
01083     SPIreadBytes(csPin, subAddress, &temp, 1);
01084     return temp;
01085 }
01086 
01087 void LSM9DS1::SPIreadBytes(uint8_t csPin, uint8_t subAddress,
01088                             uint8_t * dest, uint8_t count)
01089 {
01090     // To indicate a read, set bit 0 (msb) of first byte to 1
01091     uint8_t rAddress = 0x80 | (subAddress & 0x3F);
01092     // Mag SPI port is different. If we're reading multiple bytes, 
01093     // set bit 1 to 1. The remaining six bytes are the address to be read
01094     if ((csPin == _mAddress) && count > 1)
01095         rAddress |= 0x40;
01096     
01097     /* 
01098     digitalWrite(csPin, LOW); // Initiate communication
01099     SPI.transfer(rAddress);
01100     for (int i=0; i<count; i++)
01101     {
01102         dest[i] = SPI.transfer(0x00); // Read into destination array
01103     }
01104     digitalWrite(csPin, HIGH); // Close communication
01105     */
01106 }
01107 
01108 void LSM9DS1::initI2C()
01109 {
01110     /* 
01111     Wire.begin();   // Initialize I2C library
01112     */
01113     
01114     //already initialized in constructor!
01115 }
01116 
01117 // Wire.h read and write protocols
01118 void LSM9DS1::I2CwriteByte(uint8_t address, uint8_t subAddress, uint8_t data)
01119 {
01120     /* 
01121     Wire.beginTransmission(address);  // Initialize the Tx buffer
01122     Wire.write(subAddress);           // Put slave register address in Tx buffer
01123     Wire.write(data);                 // Put data in Tx buffer
01124     Wire.endTransmission();           // Send the Tx buffer
01125     */
01126     char temp_data[2] = {subAddress, data};
01127     i2c.write(address, temp_data, 2);
01128 }
01129 
01130 uint8_t LSM9DS1::I2CreadByte(uint8_t address, uint8_t subAddress)
01131 {
01132     /* 
01133     int timeout = LSM9DS1_COMMUNICATION_TIMEOUT;
01134     uint8_t data; // `data` will store the register data    
01135     
01136     Wire.beginTransmission(address);         // Initialize the Tx buffer
01137     Wire.write(subAddress);                  // Put slave register address in Tx buffer
01138     Wire.endTransmission(true);             // Send the Tx buffer, but send a restart to keep connection alive
01139     Wire.requestFrom(address, (uint8_t) 1);  // Read one byte from slave register address 
01140     while ((Wire.available() < 1) && (timeout-- > 0))
01141         delay(1);
01142     
01143     if (timeout <= 0)
01144         return 255; //! Bad! 255 will be misinterpreted as a good value.
01145     
01146     data = Wire.read();                      // Fill Rx buffer with result
01147     return data;                             // Return data read from slave register
01148     */
01149     char data;
01150     char temp[1] = {subAddress};
01151     
01152     i2c.write(address, temp, 1);
01153     //i2c.write(address & 0xFE);
01154     temp[1] = 0x00;
01155     i2c.write(address, temp, 1);
01156     //i2c.write( address | 0x01);
01157     int a = i2c.read(address, &data, 1);
01158     return data;
01159 }
01160 
01161 uint8_t LSM9DS1::I2CreadBytes(uint8_t address, uint8_t subAddress, uint8_t * dest, uint8_t count)
01162 {  
01163     /* 
01164     int timeout = LSM9DS1_COMMUNICATION_TIMEOUT;
01165     Wire.beginTransmission(address);   // Initialize the Tx buffer
01166     // Next send the register to be read. OR with 0x80 to indicate multi-read.
01167     Wire.write(subAddress | 0x80);     // Put slave register address in Tx buffer
01168 
01169     Wire.endTransmission(true);             // Send the Tx buffer, but send a restart to keep connection alive
01170     uint8_t i = 0;
01171     Wire.requestFrom(address, count);  // Read bytes from slave register address 
01172     while ((Wire.available() < count) && (timeout-- > 0))
01173         delay(1);
01174     if (timeout <= 0)
01175         return -1;
01176     
01177     for (int i=0; i<count;)
01178     {
01179         if (Wire.available())
01180         {
01181             dest[i++] = Wire.read();
01182         }
01183     }
01184     return count;
01185     */
01186     int i;
01187     char temp_dest[count];
01188     char temp[1] = {subAddress};
01189     i2c.write(address, temp, 1);
01190     i2c.read(address, temp_dest, count);
01191     
01192     //i2c doesn't take uint8_ts, but rather chars so do this nasty af conversion
01193     for (i=0; i < count; i++) {
01194         dest[i] = temp_dest[i];    
01195     }
01196     return count;
01197 }