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 I2C i2c(PB_9, PB_8);
00045 init(IMU_MODE_I2C, xgAddr, mAddr);} // dont know about 0xD6 or 0x3B
00046 
00047 /*
00048 LSM9DS1::LSM9DS1()
00049 {
00050     init(IMU_MODE_I2C, LSM9DS1_AG_ADDR(1), LSM9DS1_M_ADDR(1));
00051 }
00052 
00053 LSM9DS1::LSM9DS1(interface_mode interface, uint8_t xgAddr, uint8_t mAddr)
00054 {
00055     init(interface, xgAddr, mAddr);
00056 }
00057 */
00058 
00059 
00060 void LSM9DS1::init(interface_mode interface, uint8_t xgAddr, uint8_t mAddr)
00061 {
00062     settings.device.commInterface = interface;
00063     settings.device.agAddress = xgAddr;
00064     settings.device.mAddress = mAddr;
00065 
00066     settings.gyro.enabled = true;
00067     settings.gyro.enableX = true;
00068     settings.gyro.enableY = true;
00069     settings.gyro.enableZ = true;
00070     // gyro scale can be 245, 500, or 2000
00071     settings.gyro.scale = 245;
00072     // gyro sample rate: value between 1-6
00073     // 1 = 14.9    4 = 238
00074     // 2 = 59.5    5 = 476
00075     // 3 = 119     6 = 952
00076     settings.gyro.sampleRate = 6;
00077     // gyro cutoff frequency: value between 0-3
00078     // Actual value of cutoff frequency depends
00079     // on sample rate.
00080     settings.gyro.bandwidth = 0;
00081     settings.gyro.lowPowerEnable = false;
00082     settings.gyro.HPFEnable = false;
00083     // Gyro HPF cutoff frequency: value between 0-9
00084     // Actual value depends on sample rate. Only applies
00085     // if gyroHPFEnable is true.
00086     settings.gyro.HPFCutoff = 0;
00087     settings.gyro.flipX = false;
00088     settings.gyro.flipY = false;
00089     settings.gyro.flipZ = false;
00090     settings.gyro.orientation = 0;
00091     settings.gyro.latchInterrupt = true;
00092 
00093     settings.accel.enabled = true;
00094     settings.accel.enableX = true;
00095     settings.accel.enableY = true;
00096     settings.accel.enableZ = true;
00097     // accel scale can be 2, 4, 8, or 16
00098     settings.accel.scale = 2;
00099     // accel sample rate can be 1-6
00100     // 1 = 10 Hz    4 = 238 Hz
00101     // 2 = 50 Hz    5 = 476 Hz
00102     // 3 = 119 Hz   6 = 952 Hz
00103     settings.accel.sampleRate = 6;
00104     // Accel cutoff freqeuncy can be any value between -1 - 3. 
00105     // -1 = bandwidth determined by sample rate
00106     // 0 = 408 Hz   2 = 105 Hz
00107     // 1 = 211 Hz   3 = 50 Hz
00108     settings.accel.bandwidth = -1;
00109     settings.accel.highResEnable = false;
00110     // accelHighResBandwidth can be any value between 0-3
00111     // LP cutoff is set to a factor of sample rate
00112     // 0 = ODR/50    2 = ODR/9
00113     // 1 = ODR/100   3 = ODR/400
00114     settings.accel.highResBandwidth = 0;
00115 
00116     settings.mag.enabled = true;
00117     // mag scale can be 4, 8, 12, or 16
00118     settings.mag.scale = 4;
00119     // mag data rate can be 0-7
00120     // 0 = 0.625 Hz  4 = 10 Hz
00121     // 1 = 1.25 Hz   5 = 20 Hz
00122     // 2 = 2.5 Hz    6 = 40 Hz
00123     // 3 = 5 Hz      7 = 80 Hz
00124     settings.mag.sampleRate = 7;
00125     settings.mag.tempCompensationEnable = false;
00126     // magPerformance can be any value between 0-3
00127     // 0 = Low power mode      2 = high performance
00128     // 1 = medium performance  3 = ultra-high performance
00129     settings.mag.XYPerformance = 3;
00130     settings.mag.ZPerformance = 3;
00131     settings.mag.lowPowerEnable = false;
00132     // magOperatingMode can be 0-2
00133     // 0 = continuous conversion
00134     // 1 = single-conversion
00135     // 2 = power down
00136     settings.mag.operatingMode = 0;
00137 
00138     settings.temp.enabled = true;
00139     for (int i=0; i<3; i++)
00140     {
00141         gBias[i] = 0;
00142         aBias[i] = 0;
00143         mBias[i] = 0;
00144         gBiasRaw[i] = 0;
00145         aBiasRaw[i] = 0;
00146         mBiasRaw[i] = 0;
00147     }
00148     _autoCalc = false;
00149 }
00150 
00151 
00152 uint16_t LSM9DS1::begin()
00153 {
00154     //! Todo: don't use _xgAddress or _mAddress, duplicating memory
00155     _xgAddress = settings.device.agAddress;
00156     _mAddress = settings.device.mAddress;
00157     
00158     constrainScales();
00159     // Once we have the scale values, we can calculate the resolution
00160     // of each sensor. That's what these functions are for. One for each sensor
00161     calcgRes(); // Calculate DPS / ADC tick, stored in gRes variable
00162     calcmRes(); // Calculate Gs / ADC tick, stored in mRes variable
00163     calcaRes(); // Calculate g / ADC tick, stored in aRes variable
00164     
00165     // Now, initialize our hardware interface.
00166     if (settings.device.commInterface == IMU_MODE_I2C)  // If we're using I2C
00167         initI2C();  // Initialize I2C
00168     else if (settings.device.commInterface == IMU_MODE_SPI)     // else, if we're using SPI
00169         initSPI();  // Initialize SPI
00170         
00171     // To verify communication, we can read from the WHO_AM_I register of
00172     // each device. Store those in a variable so we can return them.
00173     uint8_t mTest = mReadByte(WHO_AM_I_M);      // Read the gyro WHO_AM_I
00174     uint8_t xgTest = xgReadByte(WHO_AM_I_XG);   // Read the accel/mag WHO_AM_I
00175     ////pc.printf("%x, %x, %x, %x\n\r", mTest, xgTest, _xgAddress, _mAddress);
00176     uint16_t whoAmICombined = (xgTest << 8) | mTest;
00177     
00178     if (whoAmICombined != ((WHO_AM_I_AG_RSP << 8) | WHO_AM_I_M_RSP))
00179         return 0;
00180     
00181     // Gyro initialization stuff:
00182     initGyro(); // This will "turn on" the gyro. Setting up interrupts, etc.
00183     
00184     // Accelerometer initialization stuff:
00185     initAccel(); // "Turn on" all axes of the accel. Set up interrupts, etc.
00186     
00187     // Magnetometer initialization stuff:
00188     initMag(); // "Turn on" all axes of the mag. Set up interrupts, etc.
00189 
00190     // Once everything is initialized, return the WHO_AM_I registers we read:
00191     return whoAmICombined;
00192 }
00193 
00194 void LSM9DS1::initGyro()
00195 {
00196     uint8_t tempRegValue = 0;
00197     
00198     // CTRL_REG1_G (Default value: 0x00)
00199     // [ODR_G2][ODR_G1][ODR_G0][FS_G1][FS_G0][0][BW_G1][BW_G0]
00200     // ODR_G[2:0] - Output data rate selection
00201     // FS_G[1:0] - Gyroscope full-scale selection
00202     // BW_G[1:0] - Gyroscope bandwidth selection
00203     
00204     // To disable gyro, set sample rate bits to 0. We'll only set sample
00205     // rate if the gyro is enabled.
00206     if (settings.gyro.enabled)
00207     {
00208         tempRegValue = (settings.gyro.sampleRate & 0x07) << 5;
00209     }
00210     switch (settings.gyro.scale)
00211     {
00212         case 500:
00213             tempRegValue |= (0x1 << 3);
00214             break;
00215         case 2000:
00216             tempRegValue |= (0x3 << 3);
00217             break;
00218         // Otherwise we'll set it to 245 dps (0x0 << 4)
00219     }
00220     tempRegValue |= (settings.gyro.bandwidth & 0x3);
00221     xgWriteByte(CTRL_REG1_G, tempRegValue);
00222     
00223     // CTRL_REG2_G (Default value: 0x00)
00224     // [0][0][0][0][INT_SEL1][INT_SEL0][OUT_SEL1][OUT_SEL0]
00225     // INT_SEL[1:0] - INT selection configuration
00226     // OUT_SEL[1:0] - Out selection configuration
00227     xgWriteByte(CTRL_REG2_G, 0x00); 
00228     
00229     // CTRL_REG3_G (Default value: 0x00)
00230     // [LP_mode][HP_EN][0][0][HPCF3_G][HPCF2_G][HPCF1_G][HPCF0_G]
00231     // LP_mode - Low-power mode enable (0: disabled, 1: enabled)
00232     // HP_EN - HPF enable (0:disabled, 1: enabled)
00233     // HPCF_G[3:0] - HPF cutoff frequency
00234     tempRegValue = settings.gyro.lowPowerEnable ? (1<<7) : 0;
00235     if (settings.gyro.HPFEnable)
00236     {
00237         tempRegValue |= (1<<6) | (settings.gyro.HPFCutoff & 0x0F);
00238     }
00239     xgWriteByte(CTRL_REG3_G, tempRegValue);
00240     
00241     // CTRL_REG4 (Default value: 0x38)
00242     // [0][0][Zen_G][Yen_G][Xen_G][0][LIR_XL1][4D_XL1]
00243     // Zen_G - Z-axis output enable (0:disable, 1:enable)
00244     // Yen_G - Y-axis output enable (0:disable, 1:enable)
00245     // Xen_G - X-axis output enable (0:disable, 1:enable)
00246     // LIR_XL1 - Latched interrupt (0:not latched, 1:latched)
00247     // 4D_XL1 - 4D option on interrupt (0:6D used, 1:4D used)
00248     tempRegValue = 0;
00249     if (settings.gyro.enableZ) tempRegValue |= (1<<5);
00250     if (settings.gyro.enableY) tempRegValue |= (1<<4);
00251     if (settings.gyro.enableX) tempRegValue |= (1<<3);
00252     if (settings.gyro.latchInterrupt) tempRegValue |= (1<<1);
00253     xgWriteByte(CTRL_REG4, tempRegValue);
00254     
00255     // ORIENT_CFG_G (Default value: 0x00)
00256     // [0][0][SignX_G][SignY_G][SignZ_G][Orient_2][Orient_1][Orient_0]
00257     // SignX_G - Pitch axis (X) angular rate sign (0: positive, 1: negative)
00258     // Orient [2:0] - Directional user orientation selection
00259     tempRegValue = 0;
00260     if (settings.gyro.flipX) tempRegValue |= (1<<5);
00261     if (settings.gyro.flipY) tempRegValue |= (1<<4);
00262     if (settings.gyro.flipZ) tempRegValue |= (1<<3);
00263     xgWriteByte(ORIENT_CFG_G, tempRegValue);
00264 }
00265 
00266 void LSM9DS1::initAccel()
00267 {
00268     uint8_t tempRegValue = 0;
00269     
00270     //  CTRL_REG5_XL (0x1F) (Default value: 0x38)
00271     //  [DEC_1][DEC_0][Zen_XL][Yen_XL][Zen_XL][0][0][0]
00272     //  DEC[0:1] - Decimation of accel data on OUT REG and FIFO.
00273     //      00: None, 01: 2 samples, 10: 4 samples 11: 8 samples
00274     //  Zen_XL - Z-axis output enabled
00275     //  Yen_XL - Y-axis output enabled
00276     //  Xen_XL - X-axis output enabled
00277     if (settings.accel.enableZ) tempRegValue |= (1<<5);
00278     if (settings.accel.enableY) tempRegValue |= (1<<4);
00279     if (settings.accel.enableX) tempRegValue |= (1<<3);
00280     
00281     xgWriteByte(CTRL_REG5_XL, tempRegValue);
00282     
00283     // CTRL_REG6_XL (0x20) (Default value: 0x00)
00284     // [ODR_XL2][ODR_XL1][ODR_XL0][FS1_XL][FS0_XL][BW_SCAL_ODR][BW_XL1][BW_XL0]
00285     // ODR_XL[2:0] - Output data rate & power mode selection
00286     // FS_XL[1:0] - Full-scale selection
00287     // BW_SCAL_ODR - Bandwidth selection
00288     // BW_XL[1:0] - Anti-aliasing filter bandwidth selection
00289     tempRegValue = 0;
00290     // To disable the accel, set the sampleRate bits to 0.
00291     if (settings.accel.enabled)
00292     {
00293         tempRegValue |= (settings.accel.sampleRate & 0x07) << 5;
00294     }
00295     switch (settings.accel.scale)
00296     {
00297         case 4:
00298             tempRegValue |= (0x2 << 3);
00299             break;
00300         case 8:
00301             tempRegValue |= (0x3 << 3);
00302             break;
00303         case 16:
00304             tempRegValue |= (0x1 << 3);
00305             break;
00306         // Otherwise it'll be set to 2g (0x0 << 3)
00307     }
00308     if (settings.accel.bandwidth >= 0)
00309     {
00310         tempRegValue |= (1<<2); // Set BW_SCAL_ODR
00311         tempRegValue |= (settings.accel.bandwidth & 0x03);
00312     }
00313     xgWriteByte(CTRL_REG6_XL, tempRegValue);
00314     
00315     // CTRL_REG7_XL (0x21) (Default value: 0x00)
00316     // [HR][DCF1][DCF0][0][0][FDS][0][HPIS1]
00317     // HR - High resolution mode (0: disable, 1: enable)
00318     // DCF[1:0] - Digital filter cutoff frequency
00319     // FDS - Filtered data selection
00320     // HPIS1 - HPF enabled for interrupt function
00321     tempRegValue = 0;
00322     if (settings.accel.highResEnable)
00323     {
00324         tempRegValue |= (1<<7); // Set HR bit
00325         tempRegValue |= (settings.accel.highResBandwidth & 0x3) << 5;
00326     }
00327     xgWriteByte(CTRL_REG7_XL, tempRegValue);
00328 }
00329 
00330 // This is a function that uses the FIFO to accumulate sample of accelerometer and gyro data, average
00331 // them, scales them to  gs and deg/s, respectively, and then passes the biases to the main sketch
00332 // for subtraction from all subsequent data. There are no gyro and accelerometer bias registers to store
00333 // the data as there are in the ADXL345, a precursor to the LSM9DS0, or the MPU-9150, so we have to
00334 // subtract the biases ourselves. This results in a more accurate measurement in general and can
00335 // remove errors due to imprecise or varying initial placement. Calibration of sensor data in this manner
00336 // is good practice.
00337 void LSM9DS1::calibrate(bool autoCalc)
00338 {  
00339     uint8_t data[6] = {0, 0, 0, 0, 0, 0};
00340     uint8_t samples = 0;
00341     int ii;
00342     int32_t aBiasRawTemp[3] = {0, 0, 0};
00343     int32_t gBiasRawTemp[3] = {0, 0, 0};
00344     
00345     // Turn on FIFO and set threshold to 32 samples
00346     enableFIFO(true);
00347     setFIFO(FIFO_THS, 0x1F);
00348     while (samples < 0x1F)
00349     {
00350         samples = (xgReadByte(FIFO_SRC) & 0x3F); // Read number of stored samples
00351     }
00352     for(ii = 0; ii < samples ; ii++) 
00353     {   // Read the gyro data stored in the FIFO
00354         readGyro();
00355         gBiasRawTemp[0] += gx;
00356         gBiasRawTemp[1] += gy;
00357         gBiasRawTemp[2] += gz;
00358         readAccel();
00359         aBiasRawTemp[0] += ax;
00360         aBiasRawTemp[1] += ay;
00361         aBiasRawTemp[2] += az - (int16_t)(1./aRes); // Assumes sensor facing up!
00362     }  
00363     for (ii = 0; ii < 3; ii++)
00364     {
00365         gBiasRaw[ii] = gBiasRawTemp[ii] / samples;
00366         gBias[ii] = calcGyro(gBiasRaw[ii]);
00367         aBiasRaw[ii] = aBiasRawTemp[ii] / samples;
00368         aBias[ii] = calcAccel(aBiasRaw[ii]);
00369     }
00370     
00371     enableFIFO(false);
00372     setFIFO(FIFO_OFF, 0x00);
00373     
00374     if (autoCalc) _autoCalc = true;
00375 }
00376 
00377 void LSM9DS1::calibrateMag(bool loadIn)
00378 {
00379     int i, j;
00380     int16_t magMin[3] = {0, 0, 0};
00381     int16_t magMax[3] = {0, 0, 0}; // The road warrior
00382     
00383     for (i=0; i<128; i++)
00384     {
00385         while (!magAvailable())
00386             ;
00387         readMag();
00388         int16_t magTemp[3] = {0, 0, 0};
00389         magTemp[0] = mx;        
00390         magTemp[1] = my;
00391         magTemp[2] = mz;
00392         for (j = 0; j < 3; j++)
00393         {
00394             if (magTemp[j] > magMax[j]) magMax[j] = magTemp[j];
00395             if (magTemp[j] < magMin[j]) magMin[j] = magTemp[j];
00396         }
00397     }
00398     for (j = 0; j < 3; j++)
00399     {
00400         mBiasRaw[j] = (magMax[j] + magMin[j]) / 2;
00401         mBias[j] = calcMag(mBiasRaw[j]);
00402         if (loadIn)
00403             magOffset(j, mBiasRaw[j]);
00404     }
00405     
00406 }
00407 void LSM9DS1::magOffset(uint8_t axis, int16_t offset)
00408 {
00409     if (axis > 2)
00410         return;
00411     uint8_t msb, lsb;
00412     msb = (offset & 0xFF00) >> 8;
00413     lsb = offset & 0x00FF;
00414     mWriteByte(OFFSET_X_REG_L_M + (2 * axis), lsb);
00415     mWriteByte(OFFSET_X_REG_H_M + (2 * axis), msb);
00416 }
00417 
00418 void LSM9DS1::initMag()
00419 {
00420     uint8_t tempRegValue = 0;
00421     
00422     // CTRL_REG1_M (Default value: 0x10)
00423     // [TEMP_COMP][OM1][OM0][DO2][DO1][DO0][0][ST]
00424     // TEMP_COMP - Temperature compensation
00425     // OM[1:0] - X & Y axes op mode selection
00426     //  00:low-power, 01:medium performance
00427     //  10: high performance, 11:ultra-high performance
00428     // DO[2:0] - Output data rate selection
00429     // ST - Self-test enable
00430     if (settings.mag.tempCompensationEnable) tempRegValue |= (1<<7);
00431     tempRegValue |= (settings.mag.XYPerformance & 0x3) << 5;
00432     tempRegValue |= (settings.mag.sampleRate & 0x7) << 2;
00433     mWriteByte(CTRL_REG1_M, tempRegValue);
00434     
00435     // CTRL_REG2_M (Default value 0x00)
00436     // [0][FS1][FS0][0][REBOOT][SOFT_RST][0][0]
00437     // FS[1:0] - Full-scale configuration
00438     // REBOOT - Reboot memory content (0:normal, 1:reboot)
00439     // SOFT_RST - Reset config and user registers (0:default, 1:reset)
00440     tempRegValue = 0;
00441     switch (settings.mag.scale)
00442     {
00443     case 8:
00444         tempRegValue |= (0x1 << 5);
00445         break;
00446     case 12:
00447         tempRegValue |= (0x2 << 5);
00448         break;
00449     case 16:
00450         tempRegValue |= (0x3 << 5);
00451         break;
00452     // Otherwise we'll default to 4 gauss (00)
00453     }
00454     mWriteByte(CTRL_REG2_M, tempRegValue); // +/-4Gauss
00455     
00456     // CTRL_REG3_M (Default value: 0x03)
00457     // [I2C_DISABLE][0][LP][0][0][SIM][MD1][MD0]
00458     // I2C_DISABLE - Disable I2C interace (0:enable, 1:disable)
00459     // LP - Low-power mode cofiguration (1:enable)
00460     // SIM - SPI mode selection (0:write-only, 1:read/write enable)
00461     // MD[1:0] - Operating mode
00462     //  00:continuous conversion, 01:single-conversion,
00463     //  10,11: Power-down
00464     tempRegValue = 0;
00465     if (settings.mag.lowPowerEnable) tempRegValue |= (1<<5);
00466     tempRegValue |= (settings.mag.operatingMode & 0x3);
00467     mWriteByte(CTRL_REG3_M, tempRegValue); // Continuous conversion mode
00468     
00469     // CTRL_REG4_M (Default value: 0x00)
00470     // [0][0][0][0][OMZ1][OMZ0][BLE][0]
00471     // OMZ[1:0] - Z-axis operative mode selection
00472     //  00:low-power mode, 01:medium performance
00473     //  10:high performance, 10:ultra-high performance
00474     // BLE - Big/little endian data
00475     tempRegValue = 0;
00476     tempRegValue = (settings.mag.ZPerformance & 0x3) << 2;
00477     mWriteByte(CTRL_REG4_M, tempRegValue);
00478     
00479     // CTRL_REG5_M (Default value: 0x00)
00480     // [0][BDU][0][0][0][0][0][0]
00481     // BDU - Block data update for magnetic data
00482     //  0:continuous, 1:not updated until MSB/LSB are read
00483     tempRegValue = 0;
00484     mWriteByte(CTRL_REG5_M, tempRegValue);
00485 }
00486 
00487 uint8_t LSM9DS1::accelAvailable()
00488 {
00489     uint8_t status = xgReadByte(STATUS_REG_1);
00490     
00491     return (status & (1<<0));
00492 }
00493 
00494 uint8_t LSM9DS1::gyroAvailable()
00495 {
00496     uint8_t status = xgReadByte(STATUS_REG_1);
00497     
00498     return ((status & (1<<1)) >> 1);
00499 }
00500 
00501 uint8_t LSM9DS1::tempAvailable()
00502 {
00503     uint8_t status = xgReadByte(STATUS_REG_1);
00504     
00505     return ((status & (1<<2)) >> 2);
00506 }
00507 
00508 uint8_t LSM9DS1::magAvailable(lsm9ds1_axis axis)
00509 {
00510     uint8_t status;
00511     status = mReadByte(STATUS_REG_M);
00512     
00513     return ((status & (1<<axis)) >> axis);
00514 }
00515 
00516 void LSM9DS1::readAccel()
00517 {
00518     uint8_t temp[6]; // We'll read six bytes from the accelerometer into temp   
00519     xgReadBytes(OUT_X_L_XL, temp, 6); // Read 6 bytes, beginning at OUT_X_L_XL
00520     ax = (temp[1] << 8) | temp[0]; // Store x-axis values into ax
00521     ay = (temp[3] << 8) | temp[2]; // Store y-axis values into ay
00522     az = (temp[5] << 8) | temp[4]; // Store z-axis values into az
00523     if (_autoCalc)
00524     {
00525         ax -= aBiasRaw[X_AXIS];
00526         ay -= aBiasRaw[Y_AXIS];
00527         az -= aBiasRaw[Z_AXIS];
00528     }
00529 }
00530 
00531 int16_t LSM9DS1::readAccel(lsm9ds1_axis axis)
00532 {
00533     uint8_t temp[2];
00534     int16_t value;
00535     xgReadBytes(OUT_X_L_XL + (2 * axis), temp, 2);
00536     value = (temp[1] << 8) | temp[0];
00537     
00538     if (_autoCalc)
00539         value -= aBiasRaw[axis];
00540     
00541     return value;
00542 }
00543 
00544 void LSM9DS1::readMag()
00545 {
00546     uint8_t temp[6]; // We'll read six bytes from the mag into temp 
00547     mReadBytes(OUT_X_L_M, temp, 6); // Read 6 bytes, beginning at OUT_X_L_M
00548     mx = (temp[1] << 8) | temp[0]; // Store x-axis values into mx
00549     my = (temp[3] << 8) | temp[2]; // Store y-axis values into my
00550     mz = (temp[5] << 8) | temp[4]; // Store z-axis values into mz
00551 }
00552 
00553 int16_t LSM9DS1::readMag(lsm9ds1_axis axis)
00554 {
00555     uint8_t temp[2];
00556     mReadBytes(OUT_X_L_M + (2 * axis), temp, 2);
00557     return (temp[1] << 8) | temp[0];
00558 }
00559 
00560 void LSM9DS1::readTemp()
00561 {
00562     uint8_t temp[2]; // We'll read two bytes from the temperature sensor into temp  
00563     xgReadBytes(OUT_TEMP_L, temp, 2); // Read 2 bytes, beginning at OUT_TEMP_L
00564     temperature = ((int16_t)temp[1] << 8) | temp[0];
00565 }
00566 
00567 void LSM9DS1::readGyro()
00568 {
00569     uint8_t temp[6]; // We'll read six bytes from the gyro into temp
00570     xgReadBytes(OUT_X_L_G, temp, 6); // Read 6 bytes, beginning at OUT_X_L_G
00571     gx = (temp[1] << 8) | temp[0]; // Store x-axis values into gx
00572     gy = (temp[3] << 8) | temp[2]; // Store y-axis values into gy
00573     gz = (temp[5] << 8) | temp[4]; // Store z-axis values into gz
00574     if (_autoCalc)
00575     {
00576         gx -= gBiasRaw[X_AXIS];
00577         gy -= gBiasRaw[Y_AXIS];
00578         gz -= gBiasRaw[Z_AXIS];
00579     }
00580 }
00581 
00582 int16_t LSM9DS1::readGyro(lsm9ds1_axis axis)
00583 {
00584     uint8_t temp[2];
00585     int16_t value;
00586     
00587     xgReadBytes(OUT_X_L_G + (2 * axis), temp, 2);
00588     
00589     value = (temp[1] << 8) | temp[0];
00590     
00591     if (_autoCalc)
00592         value -= gBiasRaw[axis];
00593     
00594     return value;
00595 }
00596 
00597 float LSM9DS1::calcGyro(int16_t gyro)
00598 {
00599     // Return the gyro raw reading times our pre-calculated DPS / (ADC tick):
00600     return gRes * gyro; 
00601 }
00602 
00603 float LSM9DS1::calcAccel(int16_t accel)
00604 {
00605     // Return the accel raw reading times our pre-calculated g's / (ADC tick):
00606     return aRes * accel;
00607 }
00608 
00609 float LSM9DS1::calcMag(int16_t mag)
00610 {
00611     // Return the mag raw reading times our pre-calculated Gs / (ADC tick):
00612     return mRes * mag;
00613 }
00614 
00615 void LSM9DS1::setGyroScale(uint16_t gScl)
00616 {
00617     // Read current value of CTRL_REG1_G:
00618     uint8_t ctrl1RegValue = xgReadByte(CTRL_REG1_G);
00619     // Mask out scale bits (3 & 4):
00620     ctrl1RegValue &= 0xE7;
00621     switch (gScl)
00622     {
00623         case 500:
00624             ctrl1RegValue |= (0x1 << 3);
00625             settings.gyro.scale = 500;
00626             break;
00627         case 2000:
00628             ctrl1RegValue |= (0x3 << 3);
00629             settings.gyro.scale = 2000;
00630             break;
00631         default: // Otherwise we'll set it to 245 dps (0x0 << 4)
00632             settings.gyro.scale = 245;
00633             break;
00634     }
00635     xgWriteByte(CTRL_REG1_G, ctrl1RegValue);
00636     
00637     calcgRes(); 
00638 }
00639 
00640 void LSM9DS1::setAccelScale(uint8_t aScl)
00641 {
00642     // We need to preserve the other bytes in CTRL_REG6_XL. So, first read it:
00643     uint8_t tempRegValue = xgReadByte(CTRL_REG6_XL);
00644     // Mask out accel scale bits:
00645     tempRegValue &= 0xE7;
00646     
00647     switch (aScl)
00648     {
00649         case 4:
00650             tempRegValue |= (0x2 << 3);
00651             settings.accel.scale = 4;
00652             break;
00653         case 8:
00654             tempRegValue |= (0x3 << 3);
00655             settings.accel.scale = 8;
00656             break;
00657         case 16:
00658             tempRegValue |= (0x1 << 3);
00659             settings.accel.scale = 16;
00660             break;
00661         default: // Otherwise it'll be set to 2g (0x0 << 3)
00662             settings.accel.scale = 2;
00663             break;
00664     }
00665     xgWriteByte(CTRL_REG6_XL, tempRegValue);
00666     
00667     // Then calculate a new aRes, which relies on aScale being set correctly:
00668     calcaRes();
00669 }
00670 
00671 void LSM9DS1::setMagScale(uint8_t mScl)
00672 {
00673     // We need to preserve the other bytes in CTRL_REG6_XM. So, first read it:
00674     uint8_t temp = mReadByte(CTRL_REG2_M);
00675     // Then mask out the mag scale bits:
00676     temp &= 0xFF^(0x3 << 5);
00677     
00678     switch (mScl)
00679     {
00680     case 8:
00681         temp |= (0x1 << 5);
00682         settings.mag.scale = 8;
00683         break;
00684     case 12:
00685         temp |= (0x2 << 5);
00686         settings.mag.scale = 12;
00687         break;
00688     case 16:
00689         temp |= (0x3 << 5);
00690         settings.mag.scale = 16;
00691         break;
00692     default: // Otherwise we'll default to 4 gauss (00)
00693         settings.mag.scale = 4;
00694         break;
00695     }   
00696     
00697     // And write the new register value back into CTRL_REG6_XM:
00698     mWriteByte(CTRL_REG2_M, temp);
00699     
00700     // We've updated the sensor, but we also need to update our class variables
00701     // First update mScale:
00702     //mScale = mScl;
00703     // Then calculate a new mRes, which relies on mScale being set correctly:
00704     calcmRes();
00705 }
00706 
00707 void LSM9DS1::setGyroODR(uint8_t gRate)
00708 {
00709     // Only do this if gRate is not 0 (which would disable the gyro)
00710     if ((gRate & 0x07) != 0)
00711     {
00712         // We need to preserve the other bytes in CTRL_REG1_G. So, first read it:
00713         uint8_t temp = xgReadByte(CTRL_REG1_G);
00714         // Then mask out the gyro ODR bits:
00715         temp &= 0xFF^(0x7 << 5);
00716         temp |= (gRate & 0x07) << 5;
00717         // Update our settings struct
00718         settings.gyro.sampleRate = gRate & 0x07;
00719         // And write the new register value back into CTRL_REG1_G:
00720         xgWriteByte(CTRL_REG1_G, temp);
00721     }
00722 }
00723 
00724 void LSM9DS1::setAccelODR(uint8_t aRate)
00725 {
00726     // Only do this if aRate is not 0 (which would disable the accel)
00727     if ((aRate & 0x07) != 0)
00728     {
00729         // We need to preserve the other bytes in CTRL_REG1_XM. So, first read it:
00730         uint8_t temp = xgReadByte(CTRL_REG6_XL);
00731         // Then mask out the accel ODR bits:
00732         temp &= 0x1F;
00733         // Then shift in our new ODR bits:
00734         temp |= ((aRate & 0x07) << 5);
00735         settings.accel.sampleRate = aRate & 0x07;
00736         // And write the new register value back into CTRL_REG1_XM:
00737         xgWriteByte(CTRL_REG6_XL, temp);
00738     }
00739 }
00740 
00741 void LSM9DS1::setMagODR(uint8_t mRate)
00742 {
00743     // We need to preserve the other bytes in CTRL_REG5_XM. So, first read it:
00744     uint8_t temp = mReadByte(CTRL_REG1_M);
00745     // Then mask out the mag ODR bits:
00746     temp &= 0xFF^(0x7 << 2);
00747     // Then shift in our new ODR bits:
00748     temp |= ((mRate & 0x07) << 2);
00749     settings.mag.sampleRate = mRate & 0x07;
00750     // And write the new register value back into CTRL_REG5_XM:
00751     mWriteByte(CTRL_REG1_M, temp);
00752 }
00753 
00754 void LSM9DS1::calcgRes()
00755 {
00756     gRes = ((float) settings.gyro.scale) / 32768.0;
00757 }
00758 
00759 void LSM9DS1::calcaRes()
00760 {
00761     aRes = ((float) settings.accel.scale) / 32768.0;
00762 }
00763 
00764 void LSM9DS1::calcmRes()
00765 {
00766     //mRes = ((float) settings.mag.scale) / 32768.0;
00767     switch (settings.mag.scale)
00768     {
00769     case 4:
00770         mRes = magSensitivity[0];
00771         break;
00772     case 8:
00773         mRes = magSensitivity[1];
00774         break;
00775     case 12:
00776         mRes = magSensitivity[2];
00777         break;
00778     case 16:
00779         mRes = magSensitivity[3];
00780         break;
00781     }
00782     
00783 }
00784 
00785 void LSM9DS1::configInt(interrupt_select interrupt, uint8_t generator,
00786                          h_lactive activeLow, pp_od pushPull)
00787 {
00788     // Write to INT1_CTRL or INT2_CTRL. [interupt] should already be one of
00789     // those two values.
00790     // [generator] should be an OR'd list of values from the interrupt_generators enum
00791     xgWriteByte(interrupt, generator);
00792     
00793     // Configure CTRL_REG8
00794     uint8_t temp;
00795     temp = xgReadByte(CTRL_REG8);
00796     
00797     if (activeLow) temp |= (1<<5);
00798     else temp &= ~(1<<5);
00799     
00800     if (pushPull) temp &= ~(1<<4);
00801     else temp |= (1<<4);
00802     
00803     xgWriteByte(CTRL_REG8, temp);
00804 }
00805 
00806 void LSM9DS1::configInactivity(uint8_t duration, uint8_t threshold, bool sleepOn)
00807 {
00808     uint8_t temp = 0;
00809     
00810     temp = threshold & 0x7F;
00811     if (sleepOn) temp |= (1<<7);
00812     xgWriteByte(ACT_THS, temp);
00813     
00814     xgWriteByte(ACT_DUR, duration);
00815 }
00816 
00817 uint8_t LSM9DS1::getInactivity()
00818 {
00819     uint8_t temp = xgReadByte(STATUS_REG_0);
00820     temp &= (0x10);
00821     return temp;
00822 }
00823 
00824 void LSM9DS1::configAccelInt(uint8_t generator, bool andInterrupts)
00825 {
00826     // Use variables from accel_interrupt_generator, OR'd together to create
00827     // the [generator]value.
00828     uint8_t temp = generator;
00829     if (andInterrupts) temp |= 0x80;
00830     xgWriteByte(INT_GEN_CFG_XL, temp);
00831 }
00832 
00833 void LSM9DS1::configAccelThs(uint8_t threshold, lsm9ds1_axis axis, uint8_t duration, bool wait)
00834 {
00835     // Write threshold value to INT_GEN_THS_?_XL.
00836     // axis will be 0, 1, or 2 (x, y, z respectively)
00837     xgWriteByte(INT_GEN_THS_X_XL + axis, threshold);
00838     
00839     // Write duration and wait to INT_GEN_DUR_XL
00840     uint8_t temp;
00841     temp = (duration & 0x7F);
00842     if (wait) temp |= 0x80;
00843     xgWriteByte(INT_GEN_DUR_XL, temp);
00844 }
00845 
00846 uint8_t LSM9DS1::getAccelIntSrc()
00847 {
00848     uint8_t intSrc = xgReadByte(INT_GEN_SRC_XL);
00849     
00850     // Check if the IA_XL (interrupt active) bit is set
00851     if (intSrc & (1<<6))
00852     {
00853         return (intSrc & 0x3F);
00854     }
00855     
00856     return 0;
00857 }
00858 
00859 void LSM9DS1::configGyroInt(uint8_t generator, bool aoi, bool latch)
00860 {
00861     // Use variables from accel_interrupt_generator, OR'd together to create
00862     // the [generator]value.
00863     uint8_t temp = generator;
00864     if (aoi) temp |= 0x80;
00865     if (latch) temp |= 0x40;
00866     xgWriteByte(INT_GEN_CFG_G, temp);
00867 }
00868 
00869 void LSM9DS1::configGyroThs(int16_t threshold, lsm9ds1_axis axis, uint8_t duration, bool wait)
00870 {
00871     uint8_t buffer[2];
00872     buffer[0] = (threshold & 0x7F00) >> 8;
00873     buffer[1] = (threshold & 0x00FF);
00874     // Write threshold value to INT_GEN_THS_?H_G and  INT_GEN_THS_?L_G.
00875     // axis will be 0, 1, or 2 (x, y, z respectively)
00876     xgWriteByte(INT_GEN_THS_XH_G + (axis * 2), buffer[0]);
00877     xgWriteByte(INT_GEN_THS_XH_G + 1 + (axis * 2), buffer[1]);
00878     
00879     // Write duration and wait to INT_GEN_DUR_XL
00880     uint8_t temp;
00881     temp = (duration & 0x7F);
00882     if (wait) temp |= 0x80;
00883     xgWriteByte(INT_GEN_DUR_G, temp);
00884 }
00885 
00886 uint8_t LSM9DS1::getGyroIntSrc()
00887 {
00888     uint8_t intSrc = xgReadByte(INT_GEN_SRC_G);
00889     
00890     // Check if the IA_G (interrupt active) bit is set
00891     if (intSrc & (1<<6))
00892     {
00893         return (intSrc & 0x3F);
00894     }
00895     
00896     return 0;
00897 }
00898 
00899 void LSM9DS1::configMagInt(uint8_t generator, h_lactive activeLow, bool latch)
00900 {
00901     // Mask out non-generator bits (0-4)
00902     uint8_t config = (generator & 0xE0);    
00903     // IEA bit is 0 for active-low, 1 for active-high.
00904     if (activeLow == INT_ACTIVE_HIGH) config |= (1<<2);
00905     // IEL bit is 0 for latched, 1 for not-latched
00906     if (!latch) config |= (1<<1);
00907     // As long as we have at least 1 generator, enable the interrupt
00908     if (generator != 0) config |= (1<<0);
00909     
00910     mWriteByte(INT_CFG_M, config);
00911 }
00912 
00913 void LSM9DS1::configMagThs(uint16_t threshold)
00914 {
00915     // Write high eight bits of [threshold] to INT_THS_H_M
00916     mWriteByte(INT_THS_H_M, uint8_t((threshold & 0x7F00) >> 8));
00917     // Write low eight bits of [threshold] to INT_THS_L_M
00918     mWriteByte(INT_THS_L_M, uint8_t(threshold & 0x00FF));
00919 }
00920 
00921 uint8_t LSM9DS1::getMagIntSrc()
00922 {
00923     uint8_t intSrc = mReadByte(INT_SRC_M);
00924     
00925     // Check if the INT (interrupt active) bit is set
00926     if (intSrc & (1<<0))
00927     {
00928         return (intSrc & 0xFE);
00929     }
00930     
00931     return 0;
00932 }
00933 
00934 void LSM9DS1::sleepGyro(bool enable)
00935 {
00936     uint8_t temp = xgReadByte(CTRL_REG9);
00937     if (enable) temp |= (1<<6);
00938     else temp &= ~(1<<6);
00939     xgWriteByte(CTRL_REG9, temp);
00940 }
00941 
00942 void LSM9DS1::enableFIFO(bool enable)
00943 {
00944     uint8_t temp = xgReadByte(CTRL_REG9);
00945     if (enable) temp |= (1<<1);
00946     else temp &= ~(1<<1);
00947     xgWriteByte(CTRL_REG9, temp);
00948 }
00949 
00950 void LSM9DS1::setFIFO(fifoMode_type fifoMode, uint8_t fifoThs)
00951 {
00952     // Limit threshold - 0x1F (31) is the maximum. If more than that was asked
00953     // limit it to the maximum.
00954     uint8_t threshold = fifoThs <= 0x1F ? fifoThs : 0x1F;
00955     xgWriteByte(FIFO_CTRL, ((fifoMode & 0x7) << 5) | (threshold & 0x1F));
00956 }
00957 
00958 uint8_t LSM9DS1::getFIFOSamples()
00959 {
00960     return (xgReadByte(FIFO_SRC) & 0x3F);
00961 }
00962 
00963 void LSM9DS1::constrainScales()
00964 {
00965     if ((settings.gyro.scale != 245) && (settings.gyro.scale != 500) && 
00966         (settings.gyro.scale != 2000))
00967     {
00968         settings.gyro.scale = 245;
00969     }
00970         
00971     if ((settings.accel.scale != 2) && (settings.accel.scale != 4) &&
00972         (settings.accel.scale != 8) && (settings.accel.scale != 16))
00973     {
00974         settings.accel.scale = 2;
00975     }
00976         
00977     if ((settings.mag.scale != 4) && (settings.mag.scale != 8) &&
00978         (settings.mag.scale != 12) && (settings.mag.scale != 16))
00979     {
00980         settings.mag.scale = 4;
00981     }
00982 }
00983 
00984 void LSM9DS1::xgWriteByte(uint8_t subAddress, uint8_t data)
00985 {
00986     // Whether we're using I2C or SPI, write a byte using the
00987     // gyro-specific I2C address or SPI CS pin.
00988     if (settings.device.commInterface == IMU_MODE_I2C) {
00989         printf("yo");
00990         I2CwriteByte(_xgAddress, subAddress, data);
00991     } else if (settings.device.commInterface == IMU_MODE_SPI) {
00992         SPIwriteByte(_xgAddress, subAddress, data);
00993     }
00994 }
00995 
00996 void LSM9DS1::mWriteByte(uint8_t subAddress, uint8_t data)
00997 {
00998     // Whether we're using I2C or SPI, write a byte using the
00999     // accelerometer-specific I2C address or SPI CS pin.
01000     if (settings.device.commInterface == IMU_MODE_I2C)
01001         return I2CwriteByte(_mAddress, subAddress, data);
01002     else if (settings.device.commInterface == IMU_MODE_SPI)
01003         return SPIwriteByte(_mAddress, subAddress, data);
01004 }
01005 
01006 uint8_t LSM9DS1::xgReadByte(uint8_t subAddress)
01007 {
01008     // Whether we're using I2C or SPI, read a byte using the
01009     // gyro-specific I2C address or SPI CS pin.
01010     if (settings.device.commInterface == IMU_MODE_I2C)
01011         return I2CreadByte(_xgAddress, subAddress);
01012     else if (settings.device.commInterface == IMU_MODE_SPI)
01013         return SPIreadByte(_xgAddress, subAddress);
01014 }
01015 
01016 void LSM9DS1::xgReadBytes(uint8_t subAddress, uint8_t * dest, uint8_t count)
01017 {
01018     // Whether we're using I2C or SPI, read multiple bytes using the
01019     // gyro-specific I2C address or SPI CS pin.
01020     if (settings.device.commInterface == IMU_MODE_I2C) {
01021         I2CreadBytes(_xgAddress, subAddress, dest, count);
01022     } else if (settings.device.commInterface == IMU_MODE_SPI) {
01023         SPIreadBytes(_xgAddress, subAddress, dest, count);
01024     }
01025 }
01026 
01027 uint8_t LSM9DS1::mReadByte(uint8_t subAddress)
01028 {
01029     // Whether we're using I2C or SPI, read a byte using the
01030     // accelerometer-specific I2C address or SPI CS pin.
01031     if (settings.device.commInterface == IMU_MODE_I2C)
01032         return I2CreadByte(_mAddress, subAddress);
01033     else if (settings.device.commInterface == IMU_MODE_SPI)
01034         return SPIreadByte(_mAddress, subAddress);
01035 }
01036 
01037 void LSM9DS1::mReadBytes(uint8_t subAddress, uint8_t * dest, uint8_t count)
01038 {
01039     // Whether we're using I2C or SPI, read multiple bytes using the
01040     // accelerometer-specific I2C address or SPI CS pin.
01041     if (settings.device.commInterface == IMU_MODE_I2C)
01042         I2CreadBytes(_mAddress, subAddress, dest, count);
01043     else if (settings.device.commInterface == IMU_MODE_SPI)
01044         SPIreadBytes(_mAddress, subAddress, dest, count);
01045 }
01046 
01047 void LSM9DS1::initSPI()
01048 {
01049     /* 
01050     pinMode(_xgAddress, OUTPUT);
01051     digitalWrite(_xgAddress, HIGH);
01052     pinMode(_mAddress, OUTPUT);
01053     digitalWrite(_mAddress, HIGH);
01054     
01055     SPI.begin();
01056     // Maximum SPI frequency is 10MHz, could divide by 2 here:
01057     SPI.setClockDivider(SPI_CLOCK_DIV2);
01058     // Data is read and written MSb first.
01059     SPI.setBitOrder(MSBFIRST);
01060     // Data is captured on rising edge of clock (CPHA = 0)
01061     // Base value of the clock is HIGH (CPOL = 1)
01062     SPI.setDataMode(SPI_MODE0);
01063     */
01064 }
01065 
01066 void LSM9DS1::SPIwriteByte(uint8_t csPin, uint8_t subAddress, uint8_t data)
01067 {
01068     /*
01069     digitalWrite(csPin, LOW); // Initiate communication
01070     
01071     // If write, bit 0 (MSB) should be 0
01072     // If single write, bit 1 should be 0
01073     SPI.transfer(subAddress & 0x3F); // Send Address
01074     SPI.transfer(data); // Send data
01075     
01076     digitalWrite(csPin, HIGH); // Close communication
01077     */
01078 }
01079 
01080 uint8_t LSM9DS1::SPIreadByte(uint8_t csPin, uint8_t subAddress)
01081 {
01082     uint8_t temp;
01083     // Use the multiple read function to read 1 byte. 
01084     // Value is returned to `temp`.
01085     SPIreadBytes(csPin, subAddress, &temp, 1);
01086     return temp;
01087 }
01088 
01089 void LSM9DS1::SPIreadBytes(uint8_t csPin, uint8_t subAddress,
01090                             uint8_t * dest, uint8_t count)
01091 {
01092     // To indicate a read, set bit 0 (msb) of first byte to 1
01093     uint8_t rAddress = 0x80 | (subAddress & 0x3F);
01094     // Mag SPI port is different. If we're reading multiple bytes, 
01095     // set bit 1 to 1. The remaining six bytes are the address to be read
01096     if ((csPin == _mAddress) && count > 1)
01097         rAddress |= 0x40;
01098     
01099     /* 
01100     digitalWrite(csPin, LOW); // Initiate communication
01101     SPI.transfer(rAddress);
01102     for (int i=0; i<count; i++)
01103     {
01104         dest[i] = SPI.transfer(0x00); // Read into destination array
01105     }
01106     digitalWrite(csPin, HIGH); // Close communication
01107     */
01108 }
01109 
01110 void LSM9DS1::initI2C()
01111 {
01112     /* 
01113     Wire.begin();   // Initialize I2C library
01114     */
01115     
01116     //already initialized in constructor!
01117 }
01118 
01119 // Wire.h read and write protocols
01120 void LSM9DS1::I2CwriteByte(uint8_t address, uint8_t subAddress, uint8_t data)
01121 {
01122     /* 
01123     Wire.beginTransmission(address);  // Initialize the Tx buffer
01124     Wire.write(subAddress);           // Put slave register address in Tx buffer
01125     Wire.write(data);                 // Put data in Tx buffer
01126     Wire.endTransmission();           // Send the Tx buffer
01127     */
01128     char temp_data[2] = {subAddress, data};
01129     i2c.write(address, temp_data, 2);
01130 }
01131 
01132 uint8_t LSM9DS1::I2CreadByte(uint8_t address, uint8_t subAddress)
01133 {
01134     /* 
01135     int timeout = LSM9DS1_COMMUNICATION_TIMEOUT;
01136     uint8_t data; // `data` will store the register data    
01137     
01138     Wire.beginTransmission(address);         // Initialize the Tx buffer
01139     Wire.write(subAddress);                  // Put slave register address in Tx buffer
01140     Wire.endTransmission(true);             // Send the Tx buffer, but send a restart to keep connection alive
01141     Wire.requestFrom(address, (uint8_t) 1);  // Read one byte from slave register address 
01142     while ((Wire.available() < 1) && (timeout-- > 0))
01143         delay(1);
01144     
01145     if (timeout <= 0)
01146         return 255; //! Bad! 255 will be misinterpreted as a good value.
01147     
01148     data = Wire.read();                      // Fill Rx buffer with result
01149     return data;                             // Return data read from slave register
01150     */
01151     char data;
01152     char temp[1] = {subAddress};
01153     
01154     i2c.write(address, temp, 1);
01155     //i2c.write(address & 0xFE);
01156     temp[1] = 0x00;
01157     i2c.write(address, temp, 1);
01158     //i2c.write( address | 0x01);
01159     int a = i2c.read(address, &data, 1);
01160     return data;
01161 }
01162 
01163 uint8_t LSM9DS1::I2CreadBytes(uint8_t address, uint8_t subAddress, uint8_t * dest, uint8_t count)
01164 {  
01165     /* 
01166     int timeout = LSM9DS1_COMMUNICATION_TIMEOUT;
01167     Wire.beginTransmission(address);   // Initialize the Tx buffer
01168     // Next send the register to be read. OR with 0x80 to indicate multi-read.
01169     Wire.write(subAddress | 0x80);     // Put slave register address in Tx buffer
01170 
01171     Wire.endTransmission(true);             // Send the Tx buffer, but send a restart to keep connection alive
01172     uint8_t i = 0;
01173     Wire.requestFrom(address, count);  // Read bytes from slave register address 
01174     while ((Wire.available() < count) && (timeout-- > 0))
01175         delay(1);
01176     if (timeout <= 0)
01177         return -1;
01178     
01179     for (int i=0; i<count;)
01180     {
01181         if (Wire.available())
01182         {
01183             dest[i++] = Wire.read();
01184         }
01185     }
01186     return count;
01187     */
01188     int i;
01189     char temp_dest[count];
01190     char temp[1] = {subAddress};
01191     i2c.write(address, temp, 1);
01192     i2c.read(address, temp_dest, count);
01193     
01194     //i2c doesn't take uint8_ts, but rather chars so do this nasty af conversion
01195     for (i=0; i < count; i++) {
01196         dest[i] = temp_dest[i];    
01197     }
01198     return count;
01199 }
01200 
01201