20160814

Fork of LSM9DS0 by LDSC_Robotics_TAs

Files at this revision

API Documentation at this revision

Comitter:
adam_z
Date:
Thu Jul 28 08:16:54 2016 +0000
Parent:
4:90f024c6b406
Commit message:
slightly modified.

Changed in this revision

LSM9DS0.cpp Show annotated file Show diff for this revision Revisions of this file
LSM9DS0.h Show annotated file Show diff for this revision Revisions of this file
--- a/LSM9DS0.cpp	Sat Jun 18 09:48:50 2016 +0000
+++ b/LSM9DS0.cpp	Thu Jul 28 08:16:54 2016 +0000
@@ -45,14 +45,14 @@
 {
     // interfaceMode will keep track of whether we're using SPI or I2C:
     interfaceMode = interface;
-    
+
     // xmAddress and gAddress will store the 7-bit I2C address, if using I2C.
     // If we're using SPI, these variables store the chip-select pins.
     gAddress = gAddr;
     xmAddress = xmAddr;
 }
 
-uint16_t LSM9DS0::begin(gyro_scale gScl, accel_scale aScl, mag_scale mScl, 
+uint16_t LSM9DS0::begin(gyro_scale gScl, accel_scale aScl, mag_scale mScl,
                         gyro_odr gODR, accel_odr aODR, mag_odr mODR)
 {
     // Store the given scales in class variables. These scale variables
@@ -60,45 +60,47 @@
     gScale = gScl;
     aScale = aScl;
     mScale = mScl;
-    
+
     // Once we have the scale values, we can calculate the resolution
     // of each sensor. That's what these functions are for. One for each sensor
     calcgRes(); // Calculate DPS / ADC tick, stored in gRes variable
     calcmRes(); // Calculate Gs / ADC tick, stored in mRes variable
     calcaRes(); // Calculate g / ADC tick, stored in aRes variable
-    
+
     // Now, initialize our hardware interface.
     if (interfaceMode == I2C_MODE)  // If we're using I2C
         initI2C();                  // Initialize I2C
     else if (interfaceMode == SPI_MODE)     // else, if we're using SPI
         initSPI();                          // Initialize SPI
-    
+
     // To verify communication, we can read from the WHO_AM_I register of
     // each device. Store those in a variable so we can return them.
     uint8_t gTest = gReadByte(WHO_AM_I_G);      // Read the gyro WHO_AM_I
     uint8_t xmTest = xmReadByte(WHO_AM_I_XM);   // Read the accel/mag WHO_AM_I
-    
+
     // Gyro initialization stuff:
     initGyro(); // This will "turn on" the gyro. Setting up interrupts, etc.
     setGyroODR(gODR); // Set the gyro output data rate and bandwidth.
     setGyroScale(gScale); // Set the gyro range
-    
+
     // Accelerometer initialization stuff:
     initAccel(); // "Turn on" all axes of the accel. Set up interrupts, etc.
     setAccelODR(aODR); // Set the accel data rate.
     setAccelScale(aScale); // Set the accel range.
-    
+
     // Magnetometer initialization stuff:
     initMag(); // "Turn on" all axes of the mag. Set up interrupts, etc.
     setMagODR(mODR); // Set the magnetometer output data rate.
     setMagScale(mScale); // Set the magnetometer's range.
-    
+
     setGyroOffset(0,0,0);
     setAccelOffset(0,0,0);
     setMagOffset(0,0,0);
-    
+
     // Once everything is initialized, return the WHO_AM_I registers we read:
     return (xmTest << 8) | gTest;
+    
+    init = 0;
 }
 
 void LSM9DS0::initGyro()
@@ -112,7 +114,7 @@
     PD - Power down enable (0=power down mode, 1=normal or sleep mode)
     Zen, Xen, Yen - Axis enable (o=disabled, 1=enabled) */
     gWriteByte(CTRL_REG1_G, 0xFF); // Normal mode, enable all axes
-    
+
     /* CTRL_REG2_G sets up the HPF
     Bits[7:0]: 0 0 HPM1 HPM0 HPCF3 HPCF2 HPCF1 HPCF0
     HPM[1:0] - High pass filter mode selection
@@ -122,7 +124,7 @@
         Value depends on data rate. See datasheet table 26.
     */
     gWriteByte(CTRL_REG2_G, 0x09); // Normal mode, high cutoff frequency
-    
+
     /* CTRL_REG3_G sets up interrupt and DRDY_G pins
     Bits[7:0]: I1_IINT1 I1_BOOT H_LACTIVE PP_OD I2_DRDY I2_WTM I2_ORUN I2_EMPTY
     I1_INT1 - Interrupt enable on INT_G pin (0=disable, 1=enable)
@@ -134,8 +136,8 @@
     I2_ORUN - FIFO overrun interrupt on DRDY_G (0=disable 1=enable)
     I2_EMPTY - FIFO empty interrupt on DRDY_G (0=disable 1=enable) */
     // Int1 enabled (pp, active low), data read on DRDY_G:
-    gWriteByte(CTRL_REG3_G, 0x00); 
-    
+    gWriteByte(CTRL_REG3_G, 0x00);
+
     /* CTRL_REG4_G sets the scale, update mode
     Bits[7:0] - BDU BLE FS1 FS0 - ST1 ST0 SIM
     BDU - Block data update (0=continuous, 1=output not updated until read
@@ -147,7 +149,7 @@
     SIM - SPI serial interface mode select
         0=4 wire, 1=3 wire */
     gWriteByte(CTRL_REG4_G, 0x30); // Set scale to 245 dps
-    
+
     /* CTRL_REG5_G sets up the FIFO, HPF, and INT1
     Bits[7:0] - BOOT FIFO_EN - HPen INT1_Sel1 INT1_Sel0 Out_Sel1 Out_Sel0
     BOOT - Reboot memory content (0=normal, 1=reboot)
@@ -156,7 +158,7 @@
     INT1_Sel[1:0] - Int 1 selection configuration
     Out_Sel[1:0] - Out selection configuration */
     gWriteByte(CTRL_REG5_G, 0x00);
-    
+
     // Temporary !!! For testing !!! Remove !!! Or make useful !!!
     configGyroInt(0x2A, 0, 0, 0, 0); // Trigger interrupt when above 0 DPS...
 }
@@ -172,20 +174,20 @@
     HPIS1 - HPF enabled for interrupt generator 1 (0: bypassed, 1: enabled)
     HPIS2 - HPF enabled for interrupt generator 2 (0: bypassed, 1 enabled)   */
     xmWriteByte(CTRL_REG0_XM, 0x00);
-    
+
     /* CTRL_REG1_XM (0x20) (Default value: 0x07)
     Bits (7-0): AODR3 AODR2 AODR1 AODR0 BDU AZEN AYEN AXEN
     AODR[3:0] - select the acceleration data rate:
-        0000=power down, 0001=3.125Hz, 0010=6.25Hz, 0011=12.5Hz, 
+        0000=power down, 0001=3.125Hz, 0010=6.25Hz, 0011=12.5Hz,
         0100=25Hz, 0101=50Hz, 0110=100Hz, 0111=200Hz, 1000=400Hz,
         1001=800Hz, 1010=1600Hz, (remaining combinations undefined).
     BDU - block data update for accel AND mag
         0: Continuous update
         1: Output registers aren't updated until MSB and LSB have been read.
     AZEN, AYEN, and AXEN - Acceleration x/y/z-axis enabled.
-        0: Axis disabled, 1: Axis enabled                                    */ 
+        0: Axis disabled, 1: Axis enabled                                    */
     xmWriteByte(CTRL_REG1_XM, 0x97); // 100Hz data rate, x/y/z all enabled
-    
+
     //Serial.println(xmReadByte(CTRL_REG1_XM));
     /* CTRL_REG2_XM (0x21) (Default value: 0x00)
     Bits (7-0): ABW1 ABW0 AFS2 AFS1 AFS0 AST1 AST0 SIM
@@ -198,16 +200,16 @@
     SIM - SPI mode selection
         0=4-wire, 1=3-wire                                                   */
     xmWriteByte(CTRL_REG2_XM, 0xD8); // Set scale to 2g
-    
+
     /* CTRL_REG3_XM is used to set interrupt generators on INT1_XM
     Bits (7-0): P1_BOOT P1_TAP P1_INT1 P1_INT2 P1_INTM P1_DRDYA P1_DRDYM P1_EMPTY
     */
     // Accelerometer data ready on INT1_XM (0x04)
-    xmWriteByte(CTRL_REG3_XM, 0x00); 
+    xmWriteByte(CTRL_REG3_XM, 0x00);
 }
 
 void LSM9DS0::initMag()
-{   
+{
     /* CTRL_REG5_XM enables temp sensor, sets mag resolution and data rate
     Bits (7-0): TEMP_EN M_RES1 M_RES0 M_ODR2 M_ODR1 M_ODR0 LIR2 LIR1
     TEMP_EN - Enable temperature sensor (0=disabled, 1=enabled)
@@ -219,17 +221,17 @@
     LIR1 - Latch interrupt request on INT1_SRC (cleared by readging INT1_SRC)
         0=irq not latched, 1=irq latched                                     */
     xmWriteByte(CTRL_REG5_XM, 0x74); // Mag data rate - 100 Hz, disable temperature sensor
-    
+
     /* CTRL_REG6_XM sets the magnetometer full-scale
     Bits (7-0): 0 MFS1 MFS0 0 0 0 0 0
     MFS[1:0] - Magnetic full-scale selection
     00:+/-2Gauss, 01:+/-4Gs, 10:+/-8Gs, 11:+/-12Gs                           */
     xmWriteByte(CTRL_REG6_XM, 0x40); // Mag scale to +/- 2GS
-    
+
     /* CTRL_REG7_XM sets magnetic sensor mode, low power mode, and filters
     AHPM1 AHPM0 AFDS 0 0 MLP MD1 MD0
     AHPM[1:0] - HPF mode selection
-        00=normal (resets reference registers), 01=reference signal for filtering, 
+        00=normal (resets reference registers), 01=reference signal for filtering,
         10=normal, 11=autoreset on interrupt event
     AFDS - Filtered acceleration data selection
         0=internal filter bypassed, 1=data from internal filter sent to FIFO
@@ -239,12 +241,12 @@
     MD[1:0] - Magnetic sensor mode selection (default 10)
         00=continuous-conversion, 01=single-conversion, 10 and 11=power-down */
     xmWriteByte(CTRL_REG7_XM, 0x00); // Continuous conversion mode
-    
+
     /* CTRL_REG4_XM is used to set interrupt generators on INT2_XM
     Bits (7-0): P2_TAP P2_INT1 P2_INT2 P2_INTM P2_DRDYA P2_DRDYM P2_Overrun P2_WTM
     */
     xmWriteByte(CTRL_REG4_XM, 0x00); // Magnetometer data ready on INT2_XM (0x08)
-    
+
     /* INT_CTRL_REG_M to set push-pull/open drain, and active-low/high
     Bits[7:0] - XMIEN YMIEN ZMIEN PP_OD IEA IEL 4D MIEN
     XMIEN, YMIEN, ZMIEN - Enable interrupt recognition on axis for mag data
@@ -267,69 +269,69 @@
 // remove errors due to imprecise or varying initial placement. Calibration of sensor data in this manner
 // is good practice.
 void LSM9DS0::calLSM9DS0(float * gbias, float * abias)
-{  
-  uint8_t data[6] = {0, 0, 0, 0, 0, 0};
-  int16_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
-  int samples, ii;
-  
-  // First get gyro bias
-  uint8_t c = gReadByte(CTRL_REG5_G);
-  gWriteByte(CTRL_REG5_G, c | 0x40);         // Enable gyro FIFO  
-  wait_ms(20);                                 // Wait for change to take effect
-  gWriteByte(FIFO_CTRL_REG_G, 0x20 | 0x1F);  // Enable gyro FIFO stream mode and set watermark at 32 samples
-  wait_ms(1000);  // delay 1000 milliseconds to collect FIFO samples
-  
-  samples = (gReadByte(FIFO_SRC_REG_G) & 0x1F); // Read number of stored samples
+{
+    uint8_t data[6] = {0, 0, 0, 0, 0, 0};
+    int16_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
+    int samples, ii;
+
+    // First get gyro bias
+    uint8_t c = gReadByte(CTRL_REG5_G);
+    gWriteByte(CTRL_REG5_G, c | 0x40);         // Enable gyro FIFO
+    wait_ms(20);                                 // Wait for change to take effect
+    gWriteByte(FIFO_CTRL_REG_G, 0x20 | 0x1F);  // Enable gyro FIFO stream mode and set watermark at 32 samples
+    wait_ms(1000);  // delay 1000 milliseconds to collect FIFO samples
+
+    samples = (gReadByte(FIFO_SRC_REG_G) & 0x1F); // Read number of stored samples
 
-  for(ii = 0; ii < samples ; ii++) {            // Read the gyro data stored in the FIFO
-    gReadBytes(OUT_X_L_G,  &data[0], 6);
-    gyro_bias[0] += (((int16_t)data[1] << 8) | data[0]);
-    gyro_bias[1] += (((int16_t)data[3] << 8) | data[2]);
-    gyro_bias[2] += (((int16_t)data[5] << 8) | data[4]);
-  }  
+    for(ii = 0; ii < samples ; ii++) {            // Read the gyro data stored in the FIFO
+        gReadBytes(OUT_X_L_G,  &data[0], 6);
+        gyro_bias[0] += (((int16_t)data[1] << 8) | data[0]);
+        gyro_bias[1] += (((int16_t)data[3] << 8) | data[2]);
+        gyro_bias[2] += (((int16_t)data[5] << 8) | data[4]);
+    }
+
+    gyro_bias[0] /= samples; // average the data
+    gyro_bias[1] /= samples;
+    gyro_bias[2] /= samples;
+
+    gbias[0] = (float)gyro_bias[0]*gRes;  // Properly scale the data to get deg/s
+    gbias[1] = (float)gyro_bias[1]*gRes;
+    gbias[2] = (float)gyro_bias[2]*gRes;
 
-  gyro_bias[0] /= samples; // average the data
-  gyro_bias[1] /= samples; 
-  gyro_bias[2] /= samples; 
-  
-  gbias[0] = (float)gyro_bias[0]*gRes;  // Properly scale the data to get deg/s
-  gbias[1] = (float)gyro_bias[1]*gRes;
-  gbias[2] = (float)gyro_bias[2]*gRes;
-  
-  c = gReadByte(CTRL_REG5_G);
-  gWriteByte(CTRL_REG5_G, c & ~0x40);  // Disable gyro FIFO  
-  wait_ms(20);
-  gWriteByte(FIFO_CTRL_REG_G, 0x00);   // Enable gyro bypass mode
-  
+    c = gReadByte(CTRL_REG5_G);
+    gWriteByte(CTRL_REG5_G, c & ~0x40);  // Disable gyro FIFO
+    wait_ms(20);
+    gWriteByte(FIFO_CTRL_REG_G, 0x00);   // Enable gyro bypass mode
+
 
-  //  Now get the accelerometer biases
-  c = xmReadByte(CTRL_REG0_XM);
-  xmWriteByte(CTRL_REG0_XM, c | 0x40);      // Enable accelerometer FIFO  
-  wait_ms(20);                                // Wait for change to take effect
-  xmWriteByte(FIFO_CTRL_REG, 0x20 | 0x1F);  // Enable accelerometer FIFO stream mode and set watermark at 32 samples
-  wait_ms(1000);  // delay 1000 milliseconds to collect FIFO samples
+    //  Now get the accelerometer biases
+    c = xmReadByte(CTRL_REG0_XM);
+    xmWriteByte(CTRL_REG0_XM, c | 0x40);      // Enable accelerometer FIFO
+    wait_ms(20);                                // Wait for change to take effect
+    xmWriteByte(FIFO_CTRL_REG, 0x20 | 0x1F);  // Enable accelerometer FIFO stream mode and set watermark at 32 samples
+    wait_ms(1000);  // delay 1000 milliseconds to collect FIFO samples
+
+    samples = (xmReadByte(FIFO_SRC_REG) & 0x1F); // Read number of stored accelerometer samples
 
-  samples = (xmReadByte(FIFO_SRC_REG) & 0x1F); // Read number of stored accelerometer samples
-
-   for(ii = 0; ii < samples ; ii++) {          // Read the accelerometer data stored in the FIFO
-    xmReadBytes(OUT_X_L_A, &data[0], 6);
-    accel_bias[0] += (((int16_t)data[1] << 8) | data[0]);
-    accel_bias[1] += (((int16_t)data[3] << 8) | data[2]);
-    accel_bias[2] += (((int16_t)data[5] << 8) | data[4]) - (int16_t)(1.0f/aRes); // Assumes sensor facing up!
-  }  
+    for(ii = 0; ii < samples ; ii++) {          // Read the accelerometer data stored in the FIFO
+        xmReadBytes(OUT_X_L_A, &data[0], 6);
+        accel_bias[0] += (((int16_t)data[1] << 8) | data[0]);
+        accel_bias[1] += (((int16_t)data[3] << 8) | data[2]);
+        accel_bias[2] += (((int16_t)data[5] << 8) | data[4]) - (int16_t)(1.0f/aRes); // Assumes sensor facing up!
+    }
 
-  accel_bias[0] /= samples; // average the data
-  accel_bias[1] /= samples; 
-  accel_bias[2] /= samples; 
-  
-  abias[0] = (float)accel_bias[0]*aRes; // Properly scale data to get gs
-  abias[1] = (float)accel_bias[1]*aRes;
-  abias[2] = (float)accel_bias[2]*aRes;
+    accel_bias[0] /= samples; // average the data
+    accel_bias[1] /= samples;
+    accel_bias[2] /= samples;
 
-  c = xmReadByte(CTRL_REG0_XM);
-  xmWriteByte(CTRL_REG0_XM, c & ~0x40);    // Disable accelerometer FIFO  
-  wait_ms(20);
-  xmWriteByte(FIFO_CTRL_REG, 0x00);       // Enable accelerometer bypass mode
+    abias[0] = (float)accel_bias[0]*aRes; // Properly scale data to get gs
+    abias[1] = (float)accel_bias[1]*aRes;
+    abias[2] = (float)accel_bias[2]*aRes;
+
+    c = xmReadByte(CTRL_REG0_XM);
+    xmWriteByte(CTRL_REG0_XM, c & ~0x40);    // Disable accelerometer FIFO
+    wait_ms(20);
+    xmWriteByte(FIFO_CTRL_REG, 0x00);       // Enable accelerometer bypass mode
 }
 
 //**********************
@@ -398,7 +400,7 @@
 //**********************
 void LSM9DS0::readAccel()
 {
-    uint8_t temp[6]; // We'll read six bytes from the accelerometer into temp   
+    uint8_t temp[6]; // We'll read six bytes from the accelerometer into temp
     xmReadBytes(OUT_X_L_A, temp, 6); // Read 6 bytes, beginning at OUT_X_L_A
     ax = (temp[1] << 8) | temp[0]; // Store x-axis values into ax
     ay = (temp[3] << 8) | temp[2]; // Store y-axis values into ay
@@ -459,7 +461,7 @@
 //**********************
 void LSM9DS0::readMag()
 {
-    uint8_t temp[6]; // We'll read six bytes from the mag into temp 
+    uint8_t temp[6]; // We'll read six bytes from the mag into temp
     xmReadBytes(OUT_X_L_M, temp, 6); // Read 6 bytes, beginning at OUT_X_L_M
     mx = (temp[1] << 8) | temp[0]; // Store x-axis values into mx
     my = (temp[3] << 8) | temp[2]; // Store y-axis values into my
@@ -520,7 +522,7 @@
 //**********************
 void LSM9DS0::readTemp()
 {
-    uint8_t temp[2]; // We'll read two bytes from the temperature sensor into temp  
+    uint8_t temp[2]; // We'll read two bytes from the temperature sensor into temp
     xmReadBytes(OUT_TEMP_L_XM, temp, 2); // Read 2 bytes, beginning at OUT_TEMP_L_M
     temperature = (((int16_t) temp[1] << 12) | temp[0] << 4 ) >> 4; // Temperature is a 12-bit signed integer
 }
@@ -528,7 +530,7 @@
 float LSM9DS0::calcGyro(int16_t gyro)
 {
     // Return the gyro raw reading times our pre-calculated DPS / (ADC tick):
-    return gRes * gyro; 
+    return gRes * gyro;
 }
 
 float LSM9DS0::calcAccel(int16_t accel)
@@ -553,7 +555,7 @@
     temp |= gScl << 4;
     // And write the new register value back into CTRL_REG4_G:
     gWriteByte(CTRL_REG4_G, temp);
-    
+
     // We've updated the sensor, but we also need to update our class variables
     // First update gScale:
     gScale = gScl;
@@ -571,7 +573,7 @@
     temp |= aScl << 3;
     // And write the new register value back into CTRL_REG2_XM:
     xmWriteByte(CTRL_REG2_XM, temp);
-    
+
     // We've updated the sensor, but we also need to update our class variables
     // First update aScale:
     aScale = aScl;
@@ -589,7 +591,7 @@
     temp |= mScl << 5;
     // And write the new register value back into CTRL_REG6_XM:
     xmWriteByte(CTRL_REG6_XM, temp);
-    
+
     // We've updated the sensor, but we also need to update our class variables
     // First update mScale:
     mScale = mScl;
@@ -662,26 +664,25 @@
     // Possible gyro scales (and their register bit settings) are:
     // 245 DPS (00), 500 DPS (01), 2000 DPS (10). Here's a bit of an algorithm
     // to calculate DPS/(ADC tick) based on that 2-bit value:
-    switch (gScale)
-    {
-    case G_SCALE_245DPS:
-        gRes = 245.0 / 32768.0;
-        break;
-    case G_SCALE_500DPS:
-        gRes = 500.0 / 32768.0;
-        break;
-    case G_SCALE_2000DPS:
-        gRes = 2000.0 / 32768.0;
-        break;
+    switch (gScale) {
+        case G_SCALE_245DPS:
+            gRes = 245.0 / 32768.0;
+            break;
+        case G_SCALE_500DPS:
+            gRes = 500.0 / 32768.0;
+            break;
+        case G_SCALE_2000DPS:
+            gRes = 2000.0 / 32768.0;
+            break;
     }
 }
 
 void LSM9DS0::calcaRes()
 {
     // Possible accelerometer scales (and their register bit settings) are:
-    // 2 g (000), 4g (001), 6g (010) 8g (011), 16g (100). Here's a bit of an 
+    // 2 g (000), 4g (001), 6g (010) 8g (011), 16g (100). Here's a bit of an
     // algorithm to calculate g/(ADC tick) based on that 3-bit value:
-    aRes = aScale == A_SCALE_16G ? 16.0 / 32768.0 : 
+    aRes = aScale == A_SCALE_16G ? 16.0 / 32768.0 :
            (((float) aScale + 1.0f) * 2.0f) / 32768.0f;
 }
 
@@ -690,10 +691,10 @@
     // Possible magnetometer scales (and their register bit settings) are:
     // 2 Gs (00), 4 Gs (01), 8 Gs (10) 12 Gs (11). Here's a bit of an algorithm
     // to calculate Gs/(ADC tick) based on that 2-bit value:
-    mRes = mScale == M_SCALE_2GS ? 2.0 / 32768.0 : 
+    mRes = mScale == M_SCALE_2GS ? 2.0 / 32768.0 :
            (float) (mScale << 2) / 32768.0f;
 }
-    
+
 void LSM9DS0::gWriteByte(uint8_t subAddress, uint8_t data)
 {
     // Whether we're using I2C or SPI, write a byte using the
@@ -762,7 +763,7 @@
 {
     csG_ = 1;
     csXM_= 1;
-    
+
     // Maximum SPI frequency is 10MHz:
 //    spi_.frequency(1000000);
     spi_.format(8,0b11);
@@ -775,12 +776,12 @@
         csG_ = 0;
     else if(csPin == xmAddress)
         csXM_= 0;
-    
+
     // If write, bit 0 (MSB) should be 0
     // If single write, bit 1 should be 0
     spi_.write(subAddress & 0x3F); // Send Address
     spi_.write(data); // Send data
-    
+
     csG_ = 1; // Close communication
     csXM_= 1;
 }
@@ -788,14 +789,14 @@
 uint8_t LSM9DS0::SPIreadByte(uint8_t csPin, uint8_t subAddress)
 {
     uint8_t temp;
-    // Use the multiple read function to read 1 byte. 
+    // Use the multiple read function to read 1 byte.
     // Value is returned to `temp`.
     SPIreadBytes(csPin, subAddress, &temp, 1);
     return temp;
 }
 
 void LSM9DS0::SPIreadBytes(uint8_t csPin, uint8_t subAddress,
-                            uint8_t * dest, uint8_t count)
+                           uint8_t * dest, uint8_t count)
 {
     // Initiate communication
     if(csPin == gAddress)
@@ -809,8 +810,7 @@
         spi_.write(0xC0 | (subAddress & 0x3F));
     else
         spi_.write(0x80 | (subAddress & 0x3F));
-    for (int i=0; i<count; i++)
-    {
+    for (int i=0; i<count; i++) {
         dest[i] = spi_.write(0x00); // Read into destination array
     }
     csG_ = 1; // Close communication
@@ -836,11 +836,11 @@
 uint8_t LSM9DS0::I2CreadByte(uint8_t address, uint8_t subAddress)
 {
     return 0;
-//    uint8_t data; // `data` will store the register data     
+//    uint8_t data; // `data` will store the register data
 //    Wire.beginTransmission(address);         // Initialize the Tx buffer
 //    Wire.write(subAddress);                  // Put slave register address in Tx buffer
 //    Wire.endTransmission(false);             // Send the Tx buffer, but send a restart to keep connection alive
-//    Wire.requestFrom(address, (uint8_t) 1);  // Read one byte from slave register address 
+//    Wire.requestFrom(address, (uint8_t) 1);  // Read one byte from slave register address
 //    data = Wire.read();                      // Fill Rx buffer with result
 //    return data;                             // Return data read from slave register
 }
@@ -853,8 +853,8 @@
 //    Wire.write(subAddress | 0x80);     // Put slave register address in Tx buffer
 //    Wire.endTransmission(false);       // Send the Tx buffer, but send a restart to keep connection alive
 //    uint8_t i = 0;
-//    Wire.requestFrom(address, count);  // Read bytes from slave register address 
-//    while (Wire.available()) 
+//    Wire.requestFrom(address, count);  // Read bytes from slave register address
+//    while (Wire.available())
 //    {
 //        dest[i++] = Wire.read(); // Put read results in the Rx buffer
 //    }
@@ -862,19 +862,23 @@
 
 void LSM9DS0::complementaryFilter(float * data, float dt)
 {
-    
-    float pitchAcc, rollAcc;
- 
-    /* Integrate the gyro data(deg/s) over time to get angle */
-    pitch += data[5] * dt;  // Angle around the Z-axis
+    if(init == 0) {
+        pitch = (float)atan2f(-data[0], -data[1])*180.0f/PI;
+        init = 1;
+    } else {
+        float pitchAcc, rollAcc;
+
+        /* Integrate the gyro data(deg/s) over time to get angle */
+        pitch += data[5] * dt;  // Angle around the Z-axis
 //    roll +=  data[3] * dt;  // Angle around the X-axis
-    
-    /* Turning around the X-axis results in a vector on the Y-axis
-    whereas turning around the Y-axis results in a vector on the X-axis. */
-    pitchAcc = (float)atan2f(-data[0], -data[1])*180.0f/PI;
+
+        /* Turning around the X-axis results in a vector on the Y-axis
+        whereas turning around the Y-axis results in a vector on the X-axis. */
+        pitchAcc = (float)atan2f(-data[0], -data[1])*180.0f/PI;
 //    rollAcc  = (float)atan2f(data[2], -data[1])*180.0f/PI;
-  
-    /* Apply Complementary Filter */
-    pitch = pitch * 0.999 + pitchAcc * 0.001;
+
+        /* Apply Complementary Filter */
+        pitch = pitch * 0.9999 + pitchAcc * 0.0001;
 //    roll  = roll  * 0.999 + rollAcc  * 0.001;
+    }
 }
\ No newline at end of file
--- a/LSM9DS0.h	Sat Jun 18 09:48:50 2016 +0000
+++ b/LSM9DS0.h	Thu Jul 28 08:16:54 2016 +0000
@@ -395,6 +395,7 @@
     DigitalOut csXM_;
     
     float pitch, roll;
+    bool init;
     void complementaryFilter(float * data, float dt);
 
 private: