LSM9DS1.h

00001 /******************************************************************************
00002 SFE_LSM9DS1.h
00003 SFE_LSM9DS1 Library Header File
00004 Jim Lindblom @ SparkFun Electronics
00005 Original Creation Date: February 27, 2015
00006 https://github.com/sparkfun/LSM9DS1_Breakout
00007 
00008 This file prototypes the LSM9DS1 class, implemented in SFE_LSM9DS1.cpp. In
00009 addition, it defines every register in the LSM9DS1 (both the Gyro and Accel/
00010 Magnetometer registers).
00011 
00012 Development environment specifics:
00013     IDE: Arduino 1.6.0
00014     Hardware Platform: Arduino Uno
00015     LSM9DS1 Breakout Version: 1.0
00016 
00017 This code is beerware; if you see me (or any other SparkFun employee) at the
00018 local, and you've found our code helpful, please buy us a round!
00019 
00020 Distributed as-is; no warranty is given.
00021 ******************************************************************************/
00022 #ifndef __SparkFunLSM9DS1_H__
00023 #define __SparkFunLSM9DS1_H__
00024 
00025 //#if defined(ARDUINO) && ARDUINO >= 100
00026 //  #include "Arduino.h"
00027 //#else
00028 //  #include "WProgram.h"
00029 //  #include "pins_arduino.h"
00030 //#endif
00031 
00032 #include "mbed.h"
00033 #include <stdint.h>
00034 #include "LSM9DS1_Registers.h"
00035 #include "LSM9DS1_Types.h"
00036 
00037 #define LSM9DS1_AG_ADDR 0xD4  //  Device address when ADO = 1
00038 #define LSM9DS1_M_ADDR  0x38  //  Address of magnetometer
00039 
00040 //#define LSM9DS1_AG_ADDR(sa0)    ((sa0) == 0 ? 0x6A : 0x6B)
00041 //#define LSM9DS1_M_ADDR(sa1)     ((sa1) == 0 ? 0x1C : 0x1E)
00042 
00043 enum lsm9ds1_axis {
00044     X_AXIS,
00045     Y_AXIS,
00046     Z_AXIS,
00047     ALL_AXIS
00048 };
00049 
00050 class LSM9DS1
00051 {
00052 public:
00053     IMUSettings settings;
00054     
00055     // We'll store the gyro, accel, and magnetometer readings in a series of
00056     // public class variables. Each sensor gets three variables -- one for each
00057     // axis. Call readGyro(), readAccel(), and readMag() first, before using
00058     // these variables!
00059     // These values are the RAW signed 16-bit readings from the sensors.
00060     int16_t gx, gy, gz; // x, y, and z axis readings of the gyroscope
00061     int16_t ax, ay, az; // x, y, and z axis readings of the accelerometer
00062     int16_t mx, my, mz; // x, y, and z axis readings of the magnetometer
00063     int16_t temperature; // Chip temperature
00064     float gBias[3], aBias[3], mBias[3];
00065     int16_t gBiasRaw[3], aBiasRaw[3], mBiasRaw[3];
00066     
00067     // LSM9DS1 -- LSM9DS1 class constructor
00068     // The constructor will set up a handful of private variables, and set the
00069     // communication mode as well.
00070     /**Input:
00071     *  - interface = Either IMU_MODE_SPI or IMU_MODE_I2C, whichever you're using
00072     *              to talk to the IC.
00073     *  - xgAddr = If IMU_MODE_I2C, this is the I2C address of the accel/gyroscope.
00074     *              If IMU_MODE_SPI, this is the chip select pin of the gyro (CS_AG)
00075     *  - mAddr = If IMU_MODE_I2C, this is the I2C address of the magnetometer.
00076     *              If IMU_MODE_SPI, this is the cs pin of the magnetometer (CS_M)
00077     
00078     */
00079     LSM9DS1(PinName sda, PinName scl, uint8_t xgAddr, uint8_t mAddr);
00080     //LSM9DS1(interface_mode interface, uint8_t xgAddr, uint8_t mAddr);
00081     //LSM9DS1();
00082        
00083     
00084     /** begin() -- Initialize the gyro, accelerometer, and magnetometer.
00085     *This will set up the scale and output rate of each sensor. The values set
00086     * in the IMUSettings struct will take effect after calling this function.
00087     */
00088     uint16_t begin();
00089     void selftestLSM9DS1();
00090     void accelgyrocalLSM9DS1(float * dest1, float * dest2);
00091     void calibrate(bool autoCalc = true);
00092     void calibrateMag(bool loadIn = true);
00093     void magOffset(uint8_t axis, int16_t offset);
00094     
00095     /** accelAvailable() -- Polls the accelerometer status register to check
00096     * if new data is available.
00097     * Output:  1 - New data available
00098     *          0 - No new data available
00099     */
00100     uint8_t accelAvailable();
00101     
00102     /** gyroAvailable() -- Polls the gyroscope status register to check
00103     * if new data is available.
00104     * Output:  1 - New data available
00105     *          0 - No new data available
00106     */
00107     uint8_t gyroAvailable();
00108     
00109     /** gyroAvailable() -- Polls the temperature status register to check
00110     * if new data is available.
00111     * Output:  1 - New data available
00112     *          0 - No new data available
00113     */
00114     uint8_t tempAvailable();
00115     
00116     /** magAvailable() -- Polls the accelerometer status register to check
00117     * if new data is available.
00118     * Input:
00119     *  - axis can be either X_AXIS, Y_AXIS, Z_AXIS, to check for new data
00120     *    on one specific axis. Or ALL_AXIS (default) to check for new data
00121     *    on all axes.
00122     * Output:  1 - New data available
00123     *          0 - No new data available
00124     */
00125     uint8_t magAvailable(lsm9ds1_axis axis = ALL_AXIS);
00126     
00127     /** readGyro() -- Read the gyroscope output registers.
00128     * This function will read all six gyroscope output registers.
00129     * The readings are stored in the class' gx, gy, and gz variables. Read
00130     * those _after_ calling readGyro().
00131     */
00132     void readGyro();
00133     
00134     /** int16_t readGyro(axis) -- Read a specific axis of the gyroscope.
00135     * [axis] can be any of X_AXIS, Y_AXIS, or Z_AXIS.
00136     * Input:
00137     *  - axis: can be either X_AXIS, Y_AXIS, or Z_AXIS.
00138     * Output:
00139     *  A 16-bit signed integer with sensor data on requested axis.
00140     */
00141     int16_t readGyro(lsm9ds1_axis axis);
00142     
00143     /** readAccel() -- Read the accelerometer output registers.
00144     * This function will read all six accelerometer output registers.
00145     * The readings are stored in the class' ax, ay, and az variables. Read
00146     * those _after_ calling readAccel().
00147     */
00148     void readAccel();
00149     
00150     /** int16_t readAccel(axis) -- Read a specific axis of the accelerometer.
00151     * [axis] can be any of X_AXIS, Y_AXIS, or Z_AXIS.
00152     * Input:
00153     *  - axis: can be either X_AXIS, Y_AXIS, or Z_AXIS.
00154     * Output:
00155     *  A 16-bit signed integer with sensor data on requested axis.
00156     */
00157     int16_t readAccel(lsm9ds1_axis axis);
00158     
00159     /** readMag() -- Read the magnetometer output registers.
00160     * This function will read all six magnetometer output registers.
00161     * The readings are stored in the class' mx, my, and mz variables. Read
00162     * those _after_ calling readMag().
00163     */
00164     void readMag();
00165     
00166     /** int16_t readMag(axis) -- Read a specific axis of the magnetometer.
00167     * [axis] can be any of X_AXIS, Y_AXIS, or Z_AXIS.
00168     * Input:
00169     *  - axis: can be either X_AXIS, Y_AXIS, or Z_AXIS.
00170     * Output:
00171     *  A 16-bit signed integer with sensor data on requested axis.
00172     */
00173     int16_t readMag(lsm9ds1_axis axis);
00174 
00175     /** readTemp() -- Read the temperature output register.
00176     * This function will read two temperature output registers.
00177     * The combined readings are stored in the class' temperature variables. Read
00178     * those _after_ calling readTemp().
00179     */
00180     void readTemp();
00181     
00182     /** calcGyro() -- Convert from RAW signed 16-bit value to degrees per second
00183     * This function reads in a signed 16-bit value and returns the scaled
00184     * DPS. This function relies on gScale and gRes being correct.
00185     * Input:
00186     *  - gyro = A signed 16-bit raw reading from the gyroscope.
00187     */
00188     float calcGyro(int16_t gyro);
00189     
00190     /** calcAccel() -- Convert from RAW signed 16-bit value to gravity (g's).
00191     * This function reads in a signed 16-bit value and returns the scaled
00192     * g's. This function relies on aScale and aRes being correct.
00193     * Input:
00194     *  - accel = A signed 16-bit raw reading from the accelerometer.
00195     */
00196     float calcAccel(int16_t accel);
00197     
00198     /** calcMag() -- Convert from RAW signed 16-bit value to Gauss (Gs)
00199     * This function reads in a signed 16-bit value and returns the scaled
00200     * Gs. This function relies on mScale and mRes being correct.
00201     * Input:
00202     *  - mag = A signed 16-bit raw reading from the magnetometer.
00203     */
00204     float calcMag(int16_t mag);
00205     
00206     /** setGyroScale() -- Set the full-scale range of the gyroscope.
00207     * This function can be called to set the scale of the gyroscope to 
00208     * 245, 500, or 200 degrees per second.
00209     * Input:
00210     *  - gScl = The desired gyroscope scale. Must be one of three possible
00211     *      values from the gyro_scale.
00212     */
00213     void setGyroScale(uint16_t gScl);
00214     
00215     /** setAccelScale() -- Set the full-scale range of the accelerometer.
00216     * This function can be called to set the scale of the accelerometer to
00217     * 2, 4, 6, 8, or 16 g's.
00218     * Input:
00219     *  - aScl = The desired accelerometer scale. Must be one of five possible
00220     *      values from the accel_scale.
00221     */
00222     void setAccelScale(uint8_t aScl);
00223     
00224     /** setMagScale() -- Set the full-scale range of the magnetometer.
00225     * This function can be called to set the scale of the magnetometer to
00226     * 2, 4, 8, or 12 Gs.
00227     * Input:
00228     *  - mScl = The desired magnetometer scale. Must be one of four possible
00229     *      values from the mag_scale.
00230     */
00231     void setMagScale(uint8_t mScl);
00232     
00233     /** setGyroODR() -- Set the output data rate and bandwidth of the gyroscope
00234     * Input:
00235     *  - gRate = The desired output rate and cutoff frequency of the gyro.
00236     */
00237     void setGyroODR(uint8_t gRate);
00238     
00239     // setAccelODR() -- Set the output data rate of the accelerometer
00240     // Input:
00241     //  - aRate = The desired output rate of the accel.
00242     void setAccelODR(uint8_t aRate);    
00243     
00244     // setMagODR() -- Set the output data rate of the magnetometer
00245     // Input:
00246     //  - mRate = The desired output rate of the mag.
00247     void setMagODR(uint8_t mRate);
00248     
00249     // configInactivity() -- Configure inactivity interrupt parameters
00250     // Input:
00251     //  - duration = Inactivity duration - actual value depends on gyro ODR
00252     //  - threshold = Activity Threshold
00253     //  - sleepOn = Gyroscope operating mode during inactivity.
00254     //    true: gyroscope in sleep mode
00255     //    false: gyroscope in power-down
00256     void configInactivity(uint8_t duration, uint8_t threshold, bool sleepOn);
00257     
00258     // configAccelInt() -- Configure Accelerometer Interrupt Generator
00259     // Input:
00260     //  - generator = Interrupt axis/high-low events
00261     //    Any OR'd combination of ZHIE_XL, ZLIE_XL, YHIE_XL, YLIE_XL, XHIE_XL, XLIE_XL
00262     //  - andInterrupts = AND/OR combination of interrupt events
00263     //    true: AND combination
00264     //    false: OR combination
00265     void configAccelInt(uint8_t generator, bool andInterrupts = false);
00266     
00267     // configAccelThs() -- Configure the threshold of an accelereomter axis
00268     // Input:
00269     //  - threshold = Interrupt threshold. Possible values: 0-255.
00270     //    Multiply by 128 to get the actual raw accel value.
00271     //  - axis = Axis to be configured. Either X_AXIS, Y_AXIS, or Z_AXIS
00272     //  - duration = Duration value must be above or below threshold to trigger interrupt
00273     //  - wait = Wait function on duration counter
00274     //    true: Wait for duration samples before exiting interrupt
00275     //    false: Wait function off
00276     void configAccelThs(uint8_t threshold, lsm9ds1_axis axis, uint8_t duration = 0, bool wait = 0);
00277     
00278     // configGyroInt() -- Configure Gyroscope Interrupt Generator
00279     // Input:
00280     //  - generator = Interrupt axis/high-low events
00281     //    Any OR'd combination of ZHIE_G, ZLIE_G, YHIE_G, YLIE_G, XHIE_G, XLIE_G
00282     //  - aoi = AND/OR combination of interrupt events
00283     //    true: AND combination
00284     //    false: OR combination
00285     //  - latch: latch gyroscope interrupt request.
00286     void configGyroInt(uint8_t generator, bool aoi, bool latch);
00287     
00288     // configGyroThs() -- Configure the threshold of a gyroscope axis
00289     // Input:
00290     //  - threshold = Interrupt threshold. Possible values: 0-0x7FF.
00291     //    Value is equivalent to raw gyroscope value.
00292     //  - axis = Axis to be configured. Either X_AXIS, Y_AXIS, or Z_AXIS
00293     //  - duration = Duration value must be above or below threshold to trigger interrupt
00294     //  - wait = Wait function on duration counter
00295     //    true: Wait for duration samples before exiting interrupt
00296     //    false: Wait function off
00297     void configGyroThs(int16_t threshold, lsm9ds1_axis axis, uint8_t duration, bool wait);
00298     
00299     // configInt() -- Configure INT1 or INT2 (Gyro and Accel Interrupts only)
00300     // Input:
00301     //  - interrupt = Select INT1 or INT2
00302     //    Possible values: XG_INT1 or XG_INT2
00303     //  - generator = Or'd combination of interrupt generators.
00304     //    Possible values: INT_DRDY_XL, INT_DRDY_G, INT1_BOOT (INT1 only), INT2_DRDY_TEMP (INT2 only)
00305     //    INT_FTH, INT_OVR, INT_FSS5, INT_IG_XL (INT1 only), INT1_IG_G (INT1 only), INT2_INACT (INT2 only)
00306     //  - activeLow = Interrupt active configuration
00307     //    Can be either INT_ACTIVE_HIGH or INT_ACTIVE_LOW
00308     //  - pushPull =  Push-pull or open drain interrupt configuration
00309     //    Can be either INT_PUSH_PULL or INT_OPEN_DRAIN
00310     void configInt(interrupt_select interupt, uint8_t generator,
00311                    h_lactive activeLow = INT_ACTIVE_LOW, pp_od pushPull = INT_PUSH_PULL);
00312                    
00313     /** configMagInt() -- Configure Magnetometer Interrupt Generator
00314     * Input:
00315     *  - generator = Interrupt axis/high-low events
00316     *    Any OR'd combination of ZIEN, YIEN, XIEN
00317     *  - activeLow = Interrupt active configuration
00318     *    Can be either INT_ACTIVE_HIGH or INT_ACTIVE_LOW
00319     *  - latch: latch gyroscope interrupt request.
00320     */
00321     void configMagInt(uint8_t generator, h_lactive activeLow, bool latch = true);
00322     
00323     /** configMagThs() -- Configure the threshold of a gyroscope axis
00324     * Input:
00325     *  - threshold = Interrupt threshold. Possible values: 0-0x7FF.
00326     *    Value is equivalent to raw magnetometer value.
00327     */
00328     void configMagThs(uint16_t threshold);
00329     
00330     //! getGyroIntSrc() -- Get contents of Gyroscope interrupt source register
00331     uint8_t getGyroIntSrc();
00332     
00333     //! getGyroIntSrc() -- Get contents of accelerometer interrupt source register
00334     uint8_t getAccelIntSrc();
00335     
00336     //! getGyroIntSrc() -- Get contents of magnetometer interrupt source register
00337     uint8_t getMagIntSrc();
00338     
00339     //! getGyroIntSrc() -- Get status of inactivity interrupt
00340     uint8_t getInactivity();
00341     
00342     /** sleepGyro() -- Sleep or wake the gyroscope
00343     * Input:
00344     *  - enable: True = sleep gyro. False = wake gyro.
00345     */
00346     void sleepGyro(bool enable = true);
00347     
00348     /** enableFIFO() - Enable or disable the FIFO
00349     * Input:
00350     *  - enable: true = enable, false = disable.
00351     */
00352     void enableFIFO(bool enable = true);
00353     
00354     /** setFIFO() - Configure FIFO mode and Threshold
00355     * Input:
00356     *  - fifoMode: Set FIFO mode to off, FIFO (stop when full), continuous, bypass
00357     *    Possible inputs: FIFO_OFF, FIFO_THS, FIFO_CONT_TRIGGER, FIFO_OFF_TRIGGER, FIFO_CONT
00358     *  - fifoThs: FIFO threshold level setting
00359     *    Any value from 0-0x1F is acceptable.
00360     */
00361     void setFIFO(fifoMode_type fifoMode, uint8_t fifoThs);
00362     
00363     //! getFIFOSamples() - Get number of FIFO samples
00364     uint8_t getFIFOSamples();
00365         
00366 
00367 protected:  
00368     // x_mAddress and gAddress store the I2C address or SPI chip select pin
00369     // for each sensor.
00370     uint8_t _mAddress, _xgAddress;
00371     
00372     // gRes, aRes, and mRes store the current resolution for each sensor. 
00373     // Units of these values would be DPS (or g's or Gs's) per ADC tick.
00374     // This value is calculated as (sensor scale) / (2^15).
00375     float gRes, aRes, mRes;
00376     
00377     // _autoCalc keeps track of whether we're automatically subtracting off
00378     // accelerometer and gyroscope bias calculated in calibrate().
00379     bool _autoCalc;
00380     
00381     // init() -- Sets up gyro, accel, and mag settings to default.
00382     // - interface - Sets the interface mode (IMU_MODE_I2C or IMU_MODE_SPI)
00383     // - xgAddr - Sets either the I2C address of the accel/gyro or SPI chip 
00384     //   select pin connected to the CS_XG pin.
00385     // - mAddr - Sets either the I2C address of the magnetometer or SPI chip 
00386     //   select pin connected to the CS_M pin.
00387     void init(interface_mode interface, uint8_t xgAddr, uint8_t mAddr);
00388     
00389     // initGyro() -- Sets up the gyroscope to begin reading.
00390     // This function steps through all five gyroscope control registers.
00391     // Upon exit, the following parameters will be set:
00392     //  - CTRL_REG1_G = 0x0F: Normal operation mode, all axes enabled. 
00393     //      95 Hz ODR, 12.5 Hz cutoff frequency.
00394     //  - CTRL_REG2_G = 0x00: HPF set to normal mode, cutoff frequency
00395     //      set to 7.2 Hz (depends on ODR).
00396     //  - CTRL_REG3_G = 0x88: Interrupt enabled on INT_G (set to push-pull and
00397     //      active high). Data-ready output enabled on DRDY_G.
00398     //  - CTRL_REG4_G = 0x00: Continuous update mode. Data LSB stored in lower
00399     //      address. Scale set to 245 DPS. SPI mode set to 4-wire.
00400     //  - CTRL_REG5_G = 0x00: FIFO disabled. HPF disabled.
00401     void initGyro();
00402     
00403     // initAccel() -- Sets up the accelerometer to begin reading.
00404     // This function steps through all accelerometer related control registers.
00405     // Upon exit these registers will be set as:
00406     //  - CTRL_REG0_XM = 0x00: FIFO disabled. HPF bypassed. Normal mode.
00407     //  - CTRL_REG1_XM = 0x57: 100 Hz data rate. Continuous update.
00408     //      all axes enabled.
00409     //  - CTRL_REG2_XM = 0x00:  2g scale. 773 Hz anti-alias filter BW.
00410     //  - CTRL_REG3_XM = 0x04: Accel data ready signal on INT1_XM pin.
00411     void initAccel();
00412     
00413     // initMag() -- Sets up the magnetometer to begin reading.
00414     // This function steps through all magnetometer-related control registers.
00415     // Upon exit these registers will be set as:
00416     //  - CTRL_REG4_XM = 0x04: Mag data ready signal on INT2_XM pin.
00417     //  - CTRL_REG5_XM = 0x14: 100 Hz update rate. Low resolution. Interrupt
00418     //      requests don't latch. Temperature sensor disabled.
00419     //  - CTRL_REG6_XM = 0x00:  2 Gs scale.
00420     //  - CTRL_REG7_XM = 0x00: Continuous conversion mode. Normal HPF mode.
00421     //  - INT_CTRL_REG_M = 0x09: Interrupt active-high. Enable interrupts.
00422     void initMag();
00423     
00424     // gReadByte() -- Reads a byte from a specified gyroscope register.
00425     // Input:
00426     //  - subAddress = Register to be read from.
00427     // Output:
00428     //  - An 8-bit value read from the requested address.
00429     uint8_t mReadByte(uint8_t subAddress);
00430     
00431     // gReadBytes() -- Reads a number of bytes -- beginning at an address
00432     // and incrementing from there -- from the gyroscope.
00433     // Input:
00434     //  - subAddress = Register to be read from.
00435     //  - * dest = A pointer to an array of uint8_t's. Values read will be
00436     //      stored in here on return.
00437     //  - count = The number of bytes to be read.
00438     // Output: No value is returned, but the `dest` array will store
00439     //  the data read upon exit.
00440     void mReadBytes(uint8_t subAddress, uint8_t * dest, uint8_t count);
00441     
00442     // gWriteByte() -- Write a byte to a register in the gyroscope.
00443     // Input:
00444     //  - subAddress = Register to be written to.
00445     //  - data = data to be written to the register.
00446     void mWriteByte(uint8_t subAddress, uint8_t data);
00447     
00448     // xmReadByte() -- Read a byte from a register in the accel/mag sensor
00449     // Input:
00450     //  - subAddress = Register to be read from.
00451     // Output:
00452     //  - An 8-bit value read from the requested register.
00453     uint8_t xgReadByte(uint8_t subAddress);
00454     
00455     // xmReadBytes() -- Reads a number of bytes -- beginning at an address
00456     // and incrementing from there -- from the accelerometer/magnetometer.
00457     // Input:
00458     //  - subAddress = Register to be read from.
00459     //  - * dest = A pointer to an array of uint8_t's. Values read will be
00460     //      stored in here on return.
00461     //  - count = The number of bytes to be read.
00462     // Output: No value is returned, but the `dest` array will store
00463     //  the data read upon exit.
00464     void xgReadBytes(uint8_t subAddress, uint8_t * dest, uint8_t count);
00465     
00466     // xmWriteByte() -- Write a byte to a register in the accel/mag sensor.
00467     // Input:
00468     //  - subAddress = Register to be written to.
00469     //  - data = data to be written to the register.
00470     void xgWriteByte(uint8_t subAddress, uint8_t data);
00471     
00472     // calcgRes() -- Calculate the resolution of the gyroscope.
00473     // This function will set the value of the gRes variable. gScale must
00474     // be set prior to calling this function.
00475     void calcgRes();
00476     
00477     // calcmRes() -- Calculate the resolution of the magnetometer.
00478     // This function will set the value of the mRes variable. mScale must
00479     // be set prior to calling this function.
00480     void calcmRes();
00481     
00482     // calcaRes() -- Calculate the resolution of the accelerometer.
00483     // This function will set the value of the aRes variable. aScale must
00484     // be set prior to calling this function.
00485     void calcaRes();
00486     
00487     //////////////////////
00488     // Helper Functions //
00489     //////////////////////
00490     void constrainScales();
00491     
00492     ///////////////////
00493     // SPI Functions //
00494     ///////////////////
00495     // initSPI() -- Initialize the SPI hardware.
00496     // This function will setup all SPI pins and related hardware.
00497     void initSPI();
00498     
00499     // SPIwriteByte() -- Write a byte out of SPI to a register in the device
00500     // Input:
00501     //  - csPin = The chip select pin of the slave device.
00502     //  - subAddress = The register to be written to.
00503     //  - data = Byte to be written to the register.
00504     void SPIwriteByte(uint8_t csPin, uint8_t subAddress, uint8_t data);
00505     
00506     // SPIreadByte() -- Read a single byte from a register over SPI.
00507     // Input:
00508     //  - csPin = The chip select pin of the slave device.
00509     //  - subAddress = The register to be read from.
00510     // Output:
00511     //  - The byte read from the requested address.
00512     uint8_t SPIreadByte(uint8_t csPin, uint8_t subAddress);
00513     
00514     // SPIreadBytes() -- Read a series of bytes, starting at a register via SPI
00515     // Input:
00516     //  - csPin = The chip select pin of a slave device.
00517     //  - subAddress = The register to begin reading.
00518     //  - * dest = Pointer to an array where we'll store the readings.
00519     //  - count = Number of registers to be read.
00520     // Output: No value is returned by the function, but the registers read are
00521     //      all stored in the *dest array given.
00522     void SPIreadBytes(uint8_t csPin, uint8_t subAddress, 
00523                             uint8_t * dest, uint8_t count);
00524     
00525     ///////////////////
00526     // I2C Functions //
00527     ///////////////////
00528     // initI2C() -- Initialize the I2C hardware.
00529     // This function will setup all I2C pins and related hardware.
00530     void initI2C();
00531     
00532     // I2CwriteByte() -- Write a byte out of I2C to a register in the device
00533     // Input:
00534     //  - address = The 7-bit I2C address of the slave device.
00535     //  - subAddress = The register to be written to.
00536     //  - data = Byte to be written to the register.
00537     void I2CwriteByte(uint8_t address, uint8_t subAddress, uint8_t data);
00538     
00539     // I2CreadByte() -- Read a single byte from a register over I2C.
00540     // Input:
00541     //  - address = The 7-bit I2C address of the slave device.
00542     //  - subAddress = The register to be read from.
00543     // Output:
00544     //  - The byte read from the requested address.
00545     uint8_t I2CreadByte(uint8_t address, uint8_t subAddress);
00546     
00547     // I2CreadBytes() -- Read a series of bytes, starting at a register via SPI
00548     // Input:
00549     //  - address = The 7-bit I2C address of the slave device.
00550     //  - subAddress = The register to begin reading.
00551     //  - * dest = Pointer to an array where we'll store the readings.
00552     //  - count = Number of registers to be read.
00553     // Output: No value is returned by the function, but the registers read are
00554     //      all stored in the *dest array given.
00555     uint8_t I2CreadBytes(uint8_t address, uint8_t subAddress, uint8_t * dest, uint8_t count);
00556     
00557     
00558 private:
00559     I2C i2c;
00560 };
00561 
00562 #endif // SFE_LSM9DS1_H //