usb実装中

Dependencies:   mbed MPU6050_2 HMC5883L_2 SDFileSystem3

Revision:
6:166746820555
Parent:
5:8bfe95431ec0
Child:
7:8989a4b84695
--- a/MPU9250/MPU9250.cpp	Fri Feb 08 09:11:27 2019 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,901 +0,0 @@
-#include "mbed.h"
-#include "math.h"
-#include "MPU9250.h"
-
-
-MPU9250::MPU9250(PinName sda, PinName scl, RawSerial* serial_p)
-    :
-    i2c_p(new I2C(sda,scl)),
-    i2c(*i2c_p),
-    pc_p(serial_p)
-{
-    initializeValue();
-}
-
-MPU9250::~MPU9250(){}
-
-
-/*---------- public function ----------*/
-bool MPU9250::Initialize(void){
-    uint8_t whoami;
-
-    i2c.frequency(400000);                                      // use fast (400 kHz) I2C  
-    timer.start();
-
-    whoami = Whoami_MPU9250();
-    pc_p->printf("I AM 0x%x\n\r", whoami); pc_p->printf("I SHOULD BE 0x71\n\r");
-  
-    if(whoami == IAM_MPU9250){
-        resetMPU9250();                                                 // Reset registers to default in preparation for device calibration
-        calibrateMPU9250(gyroBias, accelBias);  // Calibrate gyro and accelerometers, load biases in bias registers
-        wait(1);
-
-        initMPU9250();
-        initAK8963(magCalibration);
-    
-    pc_p->printf("Accelerometer full-scale range = %f  g\n\r", 2.0f*(float)(1<<Ascale));
-    pc_p->printf("Gyroscope full-scale range = %f  deg/s\n\r", 250.0f*(float)(1<<Gscale));
-
-    if(Mscale == 0) pc_p->printf("Magnetometer resolution = 14  bits\n\r");
-    if(Mscale == 1) pc_p->printf("Magnetometer resolution = 16  bits\n\r");
-    if(Mmode == 2) pc_p->printf("Magnetometer ODR = 8 Hz\n\r");
-    if(Mmode == 6) pc_p->printf("Magnetometer ODR = 100 Hz\n\r");
-    
-        getAres();
-        getGres();
-        getMres();
-
-    pc_p->printf("mpu9250 initialized\r\n");
-    return true;
-    }else return false;
-}
-
-bool MPU9250::sensingAcGyMg(){
-    if(readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) {  // On interrupt, check if data ready interrupt
-    sensingAccel();
-        sensingGyro();   
-        sensingMag();   
-    return true;
-  }else return false;
-}
-
-
-void MPU9250::calculatePostureAngle(float degree[3]){   
-  Now = timer.read_us();
-  deltat = (float)((Now - lastUpdate)/1000000.0f); // set integration time by time elapsed since last filter update
-  lastUpdate = Now;
-    
-//  if(lastUpdate - firstUpdate > 10000000.0f) {
-//      beta = 0.04;  // decrease filter gain after stabilized
-//      zeta = 0.015; // increasey bias drift gain after stabilized
-//  }
-    
-  // Pass gyro rate as rad/s
-  MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f,  my,  mx, mz);
-  MahonyQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);   //my, mx, mzになってるけどセンサの設置上の都合だろうか
-      
-  // Define output variables from updated quaternion---these are Tait-Bryan angles, commonly used in aircraft orientation.
-  // In this coordinate system, the positive z-axis is down toward Earth. 
-  // Yaw is the angle between Sensor x-axis and Earth magnetic North (or true North if corrected for local declination, looking down on the sensor positive yaw is counterclockwise.
-  // Pitch is angle between sensor x-axis and Earth ground plane, toward the Earth is positive, up toward the sky is negative.
-  // Roll is angle between sensor y-axis and Earth ground plane, y-axis up is positive roll.
-  // These arise from the definition of the homogeneous rotation matrix constructed from quaternions.
-  // Tait-Bryan angles as well as Euler angles are non-commutative; that is, the get the correct orientation the rotations must be
-  // applied in the correct order which for this configuration is yaw, pitch, and then roll.
-  // For more see http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles which has additional links.
-  translateQuaternionToDeg(q);
-    calibrateDegree();  
-    degree[0] = roll;
-    degree[1] = pitch;
-    degree[2] = yaw;
-}
-
-
-float MPU9250::calculateYawByMg(){
-    transformCoordinateFromCompassToMPU();
-    lpmag[0] = LPGAIN_MAG *lpmag[0] + (1 - LPGAIN_MAG)*mx;
-    lpmag[1] = LPGAIN_MAG *lpmag[1] + (1 - LPGAIN_MAG)*my;
-    lpmag[2] = LPGAIN_MAG *lpmag[2] + (1 - LPGAIN_MAG)*mz;
-    
-    float radroll = PI/180.0f * roll;
-    float radpitch = PI/180.0f * pitch;
-
-    return 180.0f/PI * atan2(lpmag[2]*sin(radpitch) - lpmag[1]*cos(radpitch),
-                                         lpmag[0]*cos(radroll) - lpmag[1]*sin(radroll)*sin(radpitch) + lpmag[2]*sin(radroll)*cos(radpitch));
-}
-
-
-// Accelerometer and gyroscope self test; check calibration wrt factory settings
-void MPU9250::MPU9250SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass
-{
-    uint8_t rawData[6] = {0, 0, 0, 0, 0, 0};
-    uint8_t selfTest[6];
-    int16_t gAvg[3], aAvg[3], aSTAvg[3], gSTAvg[3];
-    float factoryTrim[6];
-    uint8_t FS = 0;
-   
-    writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz
-    writeByte(MPU9250_ADDRESS, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz
-    writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 1<<FS); // Set full scale range for the gyro to 250 dps
-    writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz
-    writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 1<<FS); // Set full scale range for the accelerometer to 2 g
-
-    for( int ii = 0; ii < 200; ii++) { // get average current values of gyro and acclerometer
-        readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
-        aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
-    aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
-        aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
-        
-        readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
-        gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
-        gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
-        gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
-    }
-  
-    for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average current readings
-        aAvg[ii] /= 200;
-        gAvg[ii] /= 200;
-    }
-  
-    // Configure the accelerometer for self-test
-    writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g
-    writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
-    //delay(55); // Delay a while to let the device stabilize
-
-    for( int ii = 0; ii < 200; ii++) { // get average self-test values of gyro and acclerometer
-        readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
-        aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
-        aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
-        aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
-        
-        readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
-        gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
-        gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
-        gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
-    }
-  
-    for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average self-test readings
-        aSTAvg[ii] /= 200;
-        gSTAvg[ii] /= 200;
-    }
-  
- // Configure the gyro and accelerometer for normal operation
-    writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00);
-    writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00);
-    //delay(45); // Delay a while to let the device stabilize
-   
-  // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg
-    selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results
-    selfTest[1] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_ACCEL); // Y-axis accel self-test results
-    selfTest[2] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_ACCEL); // Z-axis accel self-test results
-    selfTest[3] = readByte(MPU9250_ADDRESS, SELF_TEST_X_GYRO); // X-axis gyro self-test results
-    selfTest[4] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_GYRO); // Y-axis gyro self-test results
-    selfTest[5] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_GYRO); // Z-axis gyro self-test results
-
-    // Retrieve factory self-test value from self-test code reads
-    factoryTrim[0] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation
-    factoryTrim[1] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation
-    factoryTrim[2] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation
-    factoryTrim[3] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation
-    factoryTrim[4] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation
-    factoryTrim[5] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation
- 
-    // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response
-    // To get percent, must multiply by 100
-    for (int i = 0; i < 3; i++) {
-        destination[i] = 100.0*((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i]; // Report percent differences
-        destination[i+3] = 100.0*((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3]; // Report percent differences
-    } 
-}
-
-void MPU9250::pickupAccel(float accel[3]){
-    sensingAccel();
-    accel[0] = ax;
-    accel[1] = ay;
-    accel[2] = az;
-}
-
-void MPU9250::pickupGyro(float gyro[3]){
-    sensingGyro();
-    gyro[0] = gx;
-    gyro[1] = gy;
-    gyro[2] = gz;
-}
-
-void MPU9250::pickupMag(float mag[3]){
-    sensingMag();
-    mag[0] = mx;
-    mag[1] = my;
-    mag[2] = mz;
-}
-
-float MPU9250::pickupTemp(void){
-    sensingTemp();
-    return temperature;
-}
-
-void MPU9250::displayAccel(void){
-    pc_p->printf("ax = %f", 1000*ax); 
-  pc_p->printf(" ay = %f", 1000*ay); 
-  pc_p->printf(" az = %f  mg\n\r", 1000*az); 
-}
-
-void MPU9250::displayGyro(void){
-  pc_p->printf("gx = %f", gx); 
-  pc_p->printf(" gy = %f", gy); 
-  pc_p->printf(" gz = %f  deg/s\n\r", gz); 
-}
-
-void MPU9250::displayMag(void){
-  pc_p->printf("mx = %f,", mx); 
-  pc_p->printf(" my = %f,", my); 
-  pc_p->printf(" mz = %f  mG\n\r", mz); 
-}
-
-void MPU9250::displayQuaternion(void){
-  pc_p->printf("q0 = %f\n\r", q[0]);
-  pc_p->printf("q1 = %f\n\r", q[1]);
-  pc_p->printf("q2 = %f\n\r", q[2]);
-  pc_p->printf("q3 = %f\n\r", q[3]);
-}
-
-void MPU9250::displayAngle(void){
-    //pc_p->printf("$%d %d %d;",(int)(yaw*100),(int)(pitch*100),(int)(roll*100));
-    pc_p->printf("Roll: %f\tPitch: %f\tYaw: %f\n\r",  roll,   pitch,   yaw);
-}
-
-void MPU9250::displayTemperature(void){
-    pc_p->printf(" temperature = %f  C\n\r", temperature);
-}
-
-void MPU9250::setMagBias(float bias_x, float bias_y, float bias_z){
-    magbias[0] = bias_x;
-    magbias[1] = bias_y;
-    magbias[2] = bias_z;
-}
-
-/*---------- private function ----------*/
-
-void MPU9250::writeByte(uint8_t address, uint8_t subAddress, uint8_t data)
-{
-    char data_write[2];
-    
-    data_write[0] = subAddress;
-  data_write[1] = data;
-  i2c.write(address, data_write, 2, 0);
-}
-
-char MPU9250::readByte(uint8_t address, uint8_t subAddress)
-{
-    char data[1]; // `data` will store the register data     
-    char data_write[1];
-    
-    data_write[0] = subAddress;
-    i2c.write(address, data_write, 1, 1); // no stop
-    i2c.read(address, data, 1, 0); 
-    return data[0]; 
-}
-
-void MPU9250::readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest)
-{     
-    char data[14];
-    char data_write[1];
-    
-    data_write[0] = subAddress;
-    i2c.write(address, data_write, 1, 1); // no stop
-    i2c.read(address, data, count, 0); 
-    for(int ii = 0; ii < count; ii++) {
-        dest[ii] = data[ii];
-  }
-} 
-
-void MPU9250::initializeValue(void){
-    Ascale = AFS_2G;     // AFS_2G, AFS_4G, AFS_8G, AFS_16G
-    Gscale = GFS_250DPS; // GFS_250DPS, GFS_500DPS, GFS_1000DPS, GFS_2000DPS
-    Mscale = MFS_16BITS; // MFS_14BITS or MFS_16BITS, 14-bit or 16-bit magnetometer resolution
-    Mmode = 0x06;        // Either 8 Hz 0x02) or 100 Hz (0x06) magnetometer data ODR  
-
-    GyroMeasError = PI * (60.0f / 180.0f);
-    beta = sqrt(3.0f / 4.0f) * GyroMeasError;  // compute beta
-    GyroMeasDrift = PI * (1.0f / 180.0f);      // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
-    zeta = sqrt(3.0f / 4.0f) * GyroMeasDrift;  // compute zeta, the other free parameter in the Madgwick scheme usually set to a small or zero value
-
-    deltat = 0.0f;                             // integration interval for both filter schemes
-    lastUpdate = 0, firstUpdate = 0, Now = 0;    // used to calculate integration interval                               // used to calculate integration interval
-
-    for(int i=0; i<3; i++){
-        magCalibration[i] = 0;
-        gyroBias[i] = 0;
-        accelBias[i] = 0;
-        magbias[i] = 0;
-
-        eInt[i] = 0.0f; 
-    
-        lpmag[i] = 0.0f;
-    }
-
-    q[0] = 1.0f;
-    q[1] = 0.0f;
-    q[2] = 0.0f;
-    q[3] = 0.0f;
-}
-
-void MPU9250::initMPU9250(void)
-{  
-    // Initialize MPU9250 device
-    // wake up device
-    writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors 
-    wait(0.1); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt  
-
-    // get stable time source
-    writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01);  // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
-
-    // Configure Gyro and Accelerometer
-    // Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively; 
-    // DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both
-    // Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate
-    writeByte(MPU9250_ADDRESS, CONFIG, 0x03);  
-
-    // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV)
-    writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x04);  // Use a 200 Hz rate; the same rate set in CONFIG above
- 
-    // Set gyroscope full scale range
-    // Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3
-    uint8_t c = readByte(MPU9250_ADDRESS, GYRO_CONFIG); // get current GYRO_CONFIG register value
-    // c = c & ~0xE0; // Clear self-test bits [7:5] 
-    c = c & ~0x02; // Clear Fchoice bits [1:0] 
-    c = c & ~0x18; // Clear AFS bits [4:3]
-    c = c | Gscale << 3; // Set full scale range for the gyro
-    // c =| 0x00; // Set Fchoice for the gyro to 11 by writing its inverse to bits 1:0 of GYRO_CONFIG
-    writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c ); // Write new GYRO_CONFIG value to register
-
-    // Set accelerometer full-scale range configuration
-    c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG); // get current ACCEL_CONFIG register value
-    // c = c & ~0xE0; // Clear self-test bits [7:5] 
-    c = c & ~0x18;  // Clear AFS bits [4:3]
-    c = c | Ascale << 3; // Set full scale range for the accelerometer 
-    writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c); // Write new ACCEL_CONFIG register value
-
-    // Set accelerometer sample rate configuration
-    // It is possible to get a 4 kHz sample rate from the accelerometer by choosing 1 for
-    // accel_fchoice_b bit [3]; in this case the bandwidth is 1.13 kHz
-    c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG2); // get current ACCEL_CONFIG2 register value
-    c = c & ~0x0F; // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0])  
-    c = c | 0x03;  // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz
-    writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c); // Write new ACCEL_CONFIG2 register value
-
-    // The accelerometer, gyro, and thermometer are set to 1 kHz sample rates, 
-    // but all these rates are further reduced by a factor of 5 to 200 Hz because of the SMPLRT_DIV setting
-
-    // Configure Interrupts and Bypass Enable
-    // Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips 
-    // can join the I2C bus and all can be controlled by the Arduino as master
-    writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x22);    
-    writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x01);  // Enable data ready (bit 0) interrupt
-}
-
-void MPU9250::initAK8963(float * destination)
-{
-    // First extract the factory calibration for each magnetometer axis
-    uint8_t rawData[3];  // x/y/z gyro calibration data stored here
-
-    writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer  
-    wait(0.01);
-    
-    writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x0F); // Enter Fuse ROM access mode
-    wait(0.01);
-  
-    readBytes(AK8963_ADDRESS, AK8963_ASAX, 3, &rawData[0]);  // Read the x-, y-, and z-axis calibration values
-    destination[0] =  (float)(rawData[0] - 128)/256.0f + 1.0f;   // Return x-axis sensitivity adjustment values, etc.
-    destination[1] =  (float)(rawData[1] - 128)/256.0f + 1.0f;  
-    destination[2] =  (float)(rawData[2] - 128)/256.0f + 1.0f; 
-    writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer  
-    wait(0.01);
-
-    // Configure the magnetometer for continuous read and highest resolution
-    // set Mscale bit 4 to 1 (0) to enable 16 (14) bit resolution in CNTL register,
-    // and enable continuous mode data acquisition Mmode (bits [3:0]), 0010 for 8 Hz and 0110 for 100 Hz sample rates
-    writeByte(AK8963_ADDRESS, AK8963_CNTL, Mscale << 4 | Mmode); // Set magnetometer data resolution and sample ODR
-    wait(0.01);
-}
-
-void MPU9250::resetMPU9250(void)
-{
-    // reset device
-    writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
-    wait(0.1);
-}
-
-// Function which accumulates gyro and accelerometer data after device initialization. It calculates the average
-// of the at-rest readings and then loads the resulting offsets into accelerometer and gyro bias registers.
-void MPU9250::calibrateMPU9250(float * dest1, float * dest2)
-{  
-    uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data
-    uint16_t ii, packet_count, fifo_count;
-    int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
-    int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases
-  
-    // reset device, reset all registers, clear gyro and accelerometer bias registers
-    writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
-    wait(0.1);  
-   
-    // get stable time source
-    // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
-    writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01);  
-    writeByte(MPU9250_ADDRESS, PWR_MGMT_2, 0x00); 
-    wait(0.2);
-
-    // Configure device for bias calculation
-    writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x00);   // Disable all interrupts
-    writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00);      // Disable FIFO
-    writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00);   // Turn on internal clock source
-    writeByte(MPU9250_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master
-    writeByte(MPU9250_ADDRESS, USER_CTRL, 0x00);    // Disable FIFO and I2C master modes
-    writeByte(MPU9250_ADDRESS, USER_CTRL, 0x0C);    // Reset FIFO and DMP
-    wait(0.015);
-  
-    // Configure MPU9250 gyro and accelerometer for bias calculation
-    writeByte(MPU9250_ADDRESS, CONFIG, 0x01);      // Set low-pass filter to 188 Hz
-    writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00);  // Set sample rate to 1 kHz
-    writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00);  // Set gyro full-scale to 250 degrees per second, maximum sensitivity
-    writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity
-
-    uint16_t gyrosensitivity  = 131;   // = 131 LSB/degrees/sec
-    uint16_t accelsensitivity = 16384;  // = 16384 LSB/g
-
-    // Configure FIFO to capture accelerometer and gyro data for bias calculation
-    writeByte(MPU9250_ADDRESS, USER_CTRL, 0x40);   // Enable FIFO  
-    writeByte(MPU9250_ADDRESS, FIFO_EN, 0x78);     // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9250)
-    wait(0.04); // accumulate 40 samples in 80 milliseconds = 480 bytes
-
-    // At end of sample accumulation, turn off FIFO sensor read
-    writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00);        // Disable gyro and accelerometer sensors for FIFO
-    readBytes(MPU9250_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count
-    fifo_count = ((uint16_t)data[0] << 8) | data[1];
-    packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging
-
-    for (ii = 0; ii < packet_count; ii++) {
-        int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0};
-        readBytes(MPU9250_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging
-        accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1]  ) ;  // Form signed 16-bit integer for each sample in FIFO
-        accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3]  ) ;
-        accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5]  ) ;    
-        gyro_temp[0]  = (int16_t) (((int16_t)data[6] << 8) | data[7]  ) ;
-        gyro_temp[1]  = (int16_t) (((int16_t)data[8] << 8) | data[9]  ) ;
-        gyro_temp[2]  = (int16_t) (((int16_t)data[10] << 8) | data[11]) ;
-    
-        accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases
-        accel_bias[1] += (int32_t) accel_temp[1];
-        accel_bias[2] += (int32_t) accel_temp[2];
-        gyro_bias[0]  += (int32_t) gyro_temp[0];
-        gyro_bias[1]  += (int32_t) gyro_temp[1];
-        gyro_bias[2]  += (int32_t) gyro_temp[2];
-            
-    }
-    accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases
-    accel_bias[1] /= (int32_t) packet_count;
-    accel_bias[2] /= (int32_t) packet_count;
-    gyro_bias[0]  /= (int32_t) packet_count;
-    gyro_bias[1]  /= (int32_t) packet_count;
-    gyro_bias[2]  /= (int32_t) packet_count;
-    
-  if(accel_bias[2] > 0L) {accel_bias[2] -= (int32_t) accelsensitivity;}  // Remove gravity from the z-axis accelerometer bias calculation
-  else {accel_bias[2] += (int32_t) accelsensitivity;}
- 
-    // Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup
-    data[0] = (-gyro_bias[0]/4  >> 8) & 0xFF; // Divide by 4 to get 32.9 LSB per deg/s to conform to expected bias input format
-    data[1] = (-gyro_bias[0]/4)       & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
-    data[2] = (-gyro_bias[1]/4  >> 8) & 0xFF;
-    data[3] = (-gyro_bias[1]/4)       & 0xFF;
-    data[4] = (-gyro_bias[2]/4  >> 8) & 0xFF;
-    data[5] = (-gyro_bias[2]/4)       & 0xFF;
-
-    /// Push gyro biases to hardware registers
-/*  
-    writeByte(MPU9250_ADDRESS, XG_OFFSET_H, data[0]);
-    writeByte(MPU9250_ADDRESS, XG_OFFSET_L, data[1]);
-    writeByte(MPU9250_ADDRESS, YG_OFFSET_H, data[2]);
-    writeByte(MPU9250_ADDRESS, YG_OFFSET_L, data[3]);
-    writeByte(MPU9250_ADDRESS, ZG_OFFSET_H, data[4]);
-    writeByte(MPU9250_ADDRESS, ZG_OFFSET_L, data[5]);
-*/
-    dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction
-    dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity;
-    dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity;
-
-    // Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain
-    // factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold
-    // non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature
-    // compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that
-    // the accelerometer biases calculated above must be divided by 8.
-
-    readBytes(MPU9250_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values
-    accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1];
-    readBytes(MPU9250_ADDRESS, YA_OFFSET_H, 2, &data[0]);
-    accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1];
-    readBytes(MPU9250_ADDRESS, ZA_OFFSET_H, 2, &data[0]);
-    accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1];
-  
-    uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers
-    uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis
-  
-    for(ii = 0; ii < 3; ii++) {
-        if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit
-    }
-
-  // Construct total accelerometer bias, including calculated average accelerometer bias from above
-    accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale)
-    accel_bias_reg[1] -= (accel_bias[1]/8);
-    accel_bias_reg[2] -= (accel_bias[2]/8);
- 
-    data[0] = (accel_bias_reg[0] >> 8) & 0xFF;
-    data[1] = (accel_bias_reg[0])      & 0xFF;
-    data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers
-    data[2] = (accel_bias_reg[1] >> 8) & 0xFF;
-    data[3] = (accel_bias_reg[1])      & 0xFF;
-    data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers
-    data[4] = (accel_bias_reg[2] >> 8) & 0xFF;
-    data[5] = (accel_bias_reg[2])      & 0xFF;
-    data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers
-
-// Apparently this is not working for the acceleration biases in the MPU-9250
-// Are we handling the temperature correction bit properly?
-// Push accelerometer biases to hardware registers
-/*
-    writeByte(MPU9250_ADDRESS, XA_OFFSET_H, data[0]);
-    writeByte(MPU9250_ADDRESS, XA_OFFSET_L, data[1]);
-    writeByte(MPU9250_ADDRESS, YA_OFFSET_H, data[2]);
-    writeByte(MPU9250_ADDRESS, YA_OFFSET_L, data[3]);
-    writeByte(MPU9250_ADDRESS, ZA_OFFSET_H, data[4]);
-    writeByte(MPU9250_ADDRESS, ZA_OFFSET_L, data[5]);
-*/
-// Output scaled accelerometer biases for manual subtraction in the main program
-    dest2[0] = (float)accel_bias[0]/(float)accelsensitivity; 
-    dest2[1] = (float)accel_bias[1]/(float)accelsensitivity;
-    dest2[2] = (float)accel_bias[2]/(float)accelsensitivity;
-}
-
-void MPU9250::getMres(void)
-{
-    switch (Mscale)
-    {
-        // Possible magnetometer scales (and their register bit settings) are:
-        // 14 bit resolution (0) and 16 bit resolution (1)
-        case MFS_14BITS:
-                mRes = 10.0*4219.0/8190.0; // Proper scale to return milliGauss
-                break;
-        case MFS_16BITS:
-                mRes = 10.0*4219.0/32760.0; // Proper scale to return milliGauss
-                break;
-  }
-}
-
-void MPU9250::getGres(void) {
-    switch (Gscale)
-    {
-        // Possible gyro scales (and their register bit settings) are:
-        // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS  (11). 
-        // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
-        case GFS_250DPS:
-                gRes = 250.0/32768.0;
-                break;
-        case GFS_500DPS:
-                gRes = 500.0/32768.0;
-                break;
-        case GFS_1000DPS:
-                gRes = 1000.0/32768.0;
-                break;
-        case GFS_2000DPS:
-                gRes = 2000.0/32768.0;
-                break;
-  }
-}
-
-
-void MPU9250::getAres(void) 
-{
-    switch (Ascale)
-    {
-        // Possible accelerometer scales (and their register bit settings) are:
-        // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs  (11). 
-        // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
-        case AFS_2G:
-                aRes = 2.0/32768.0;
-                break;
-        case AFS_4G:
-                aRes = 4.0/32768.0;
-                break;
-        case AFS_8G:
-                aRes = 8.0/32768.0;
-                break;
-        case AFS_16G:
-                aRes = 16.0/32768.0;
-                break;
-  }
-}
-
-void MPU9250::readAccelData(int16_t * destination)
-{
-    uint8_t rawData[6];  // x/y/z accel register data stored here
-  
-    readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]);  // Read the six raw data registers into data array
-    destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ;  // Turn the MSB and LSB into a signed 16-bit value
-    destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;  
-    destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 
-}
-
-void MPU9250::readGyroData(int16_t * destination)
-{
-    uint8_t rawData[6];  // x/y/z gyro register data stored here
-  
-    readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]);  // Read the six raw data registers sequentially into data array
-    destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ;  // Turn the MSB and LSB into a signed 16-bit value
-    destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;  
-    destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 
-}
-
-void MPU9250::readMagData(int16_t * destination)
-{
-    uint8_t rawData[7];  // x/y/z gyro register data, ST2 register stored here, must read ST2 at end of data acquisition
-  
-    if(readByte(AK8963_ADDRESS, AK8963_ST1) & 0x01) { // wait for magnetometer data ready bit to be set
-        readBytes(AK8963_ADDRESS, AK8963_XOUT_L, 7, &rawData[0]);  // Read the six raw data and ST2 registers sequentially into data array
-        uint8_t c = rawData[6]; // End data read by reading ST2 register
-        if(!(c & 0x08)) { // Check if magnetic sensor overflow set, if not then report data
-            destination[0] = (int16_t)(((int16_t)rawData[1] << 8) | rawData[0]);  // Turn the MSB and LSB into a signed 16-bit value
-            destination[1] = (int16_t)(((int16_t)rawData[3] << 8) | rawData[2]) ;  // Data stored as little Endian
-            destination[2] = (int16_t)(((int16_t)rawData[5] << 8) | rawData[4]) ; 
-        }
-    }
-}
-
-int16_t MPU9250::readTempData(void)
-{
-  uint8_t rawData[2];  // x/y/z gyro register data stored here
-  
-  readBytes(MPU9250_ADDRESS, TEMP_OUT_H, 2, &rawData[0]);  // Read the two raw data registers sequentially into data array 
-  
-  return (int16_t)(((int16_t)rawData[0]) << 8 | rawData[1]) ;  // Turn the MSB and LSB into a 16-bit value
-}
-
-uint8_t MPU9250::Whoami_MPU9250(void){
-    return readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250);
-}
-
-uint8_t MPU9250::Whoami_AK8963(void){
-    return readByte(WHO_AM_I_AK8963, WHO_AM_I_AK8963);
-}
-
-void MPU9250::sensingAccel(void){
-    readAccelData(accelCount);
-    ax = (float)accelCount[0]*aRes - accelBias[0];
-    ay = (float)accelCount[1]*aRes - accelBias[1];   
-    az = (float)accelCount[2]*aRes - accelBias[2];
-}
-
-void MPU9250::sensingGyro(void){
-    readGyroData(gyroCount);
-    gx = (float)gyroCount[0]*gRes - gyroBias[0];
-    gy = (float)gyroCount[1]*gRes - gyroBias[1];  
-    gz = (float)gyroCount[2]*gRes - gyroBias[2];   
-}
-
-void MPU9250::sensingMag(void){
-    readMagData(magCount);
-    mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0];
-    my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1];  
-    mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2];
-}
-
-void MPU9250::sensingTemp(void){
-    tempCount = readTempData();
-  temperature = ((float) tempCount) / 333.87f + 21.0f; // Temperature in degrees Centigrade
-}
-
-// Implementation of Sebastian Madgwick's "...efficient orientation filter for... inertial/magnetic sensor arrays"
-// (see http://www.x-io.co.uk/category/open-source/ for examples and more details)
-// which fuses acceleration, rotation rate, and magnetic moments to produce a quaternion-based estimate of absolute
-// device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc.
-// The performance of the orientation filter is at least as good as conventional Kalman-based filtering algorithms
-// but is much less computationally intensive---it can be performed on a 3.3 V Pro Mini operating at 8 MHz!
-void MPU9250::MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
-{
-    float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3];   // short name local variable for readability
-    float norm;
-    float hx, hy, _2bx, _2bz;
-    float s1, s2, s3, s4;
-    float qDot1, qDot2, qDot3, qDot4;
-
-    // Auxiliary variables to avoid repeated arithmetic
-    float _2q1mx;
-    float _2q1my;
-    float _2q1mz;
-    float _2q2mx;
-    float _4bx;
-    float _4bz;
-    float _2q1 = 2.0f * q1;
-    float _2q2 = 2.0f * q2;
-    float _2q3 = 2.0f * q3;
-    float _2q4 = 2.0f * q4;
-    float _2q1q3 = 2.0f * q1 * q3;
-    float _2q3q4 = 2.0f * q3 * q4;
-    float q1q1 = q1 * q1;
-    float q1q2 = q1 * q2;
-    float q1q3 = q1 * q3;
-    float q1q4 = q1 * q4;
-    float q2q2 = q2 * q2;
-    float q2q3 = q2 * q3;
-    float q2q4 = q2 * q4;
-    float q3q3 = q3 * q3;
-    float q3q4 = q3 * q4;
-    float q4q4 = q4 * q4;
-
-    // Normalise accelerometer measurement
-    norm = sqrt(ax * ax + ay * ay + az * az);
-    if (norm == 0.0f) return; // handle NaN
-    norm = 1.0f/norm;
-    ax *= norm;
-    ay *= norm;
-    az *= norm;
-
-    // Normalise magnetometer measurement
-    norm = sqrt(mx * mx + my * my + mz * mz);
-    if (norm == 0.0f) return; // handle NaN
-    norm = 1.0f/norm;
-    mx *= norm;
-    my *= norm;
-    mz *= norm;
-
-    // Reference direction of Earth's magnetic field
-    _2q1mx = 2.0f * q1 * mx;
-    _2q1my = 2.0f * q1 * my;
-    _2q1mz = 2.0f * q1 * mz;
-    _2q2mx = 2.0f * q2 * mx;
-    hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4;
-    hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4;
-    _2bx = sqrt(hx * hx + hy * hy);
-    _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4;
-    _4bx = 2.0f * _2bx;
-    _4bz = 2.0f * _2bz;
-
-    // Gradient decent algorithm corrective step
-    s1 = -_2q3 * (2.0f * q2q4 - _2q1q3 - ax) + _2q2 * (2.0f * q1q2 + _2q3q4 - ay) - _2bz * q3 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q4 + _2bz * q2) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q3 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
-    s2 = _2q4 * (2.0f * q2q4 - _2q1q3 - ax) + _2q1 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q2 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + _2bz * q4 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q3 + _2bz * q1) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q4 - _4bz * q2) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
-    s3 = -_2q1 * (2.0f * q2q4 - _2q1q3 - ax) + _2q4 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q3 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + (-_4bx * q3 - _2bz * q1) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q2 + _2bz * q4) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q1 - _4bz * q3) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
-    s4 = _2q2 * (2.0f * q2q4 - _2q1q3 - ax) + _2q3 * (2.0f * q1q2 + _2q3q4 - ay) + (-_4bx * q4 + _2bz * q2) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q1 + _2bz * q3) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q2 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
-    norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4);    // normalise step magnitude
-    norm = 1.0f/norm;
-    s1 *= norm;
-    s2 *= norm;
-    s3 *= norm;
-    s4 *= norm;
-
-    // Compute rate of change of quaternion
-    qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1;
-    qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2;
-    qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3;
-    qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4;
-
-    // Integrate to yield quaternion
-    q1 += qDot1 * deltat;
-    q2 += qDot2 * deltat;
-    q3 += qDot3 * deltat;
-    q4 += qDot4 * deltat;
-    norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);    // normalise quaternion
-    norm = 1.0f/norm;
-    q[0] = q1 * norm;
-    q[1] = q2 * norm;
-    q[2] = q3 * norm;
-    q[3] = q4 * norm;
-
-}
-
-void MPU9250::MahonyQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
-{
-    float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3];   // short name local variable for readability
-    float norm;
-    float hx, hy, bx, bz;
-    float vx, vy, vz, wx, wy, wz;
-    float ex, ey, ez;
-    float pa, pb, pc;
-
-    // Auxiliary variables to avoid repeated arithmetic
-    float q1q1 = q1 * q1;
-    float q1q2 = q1 * q2;
-    float q1q3 = q1 * q3;
-    float q1q4 = q1 * q4;
-    float q2q2 = q2 * q2;
-    float q2q3 = q2 * q3;
-    float q2q4 = q2 * q4;
-    float q3q3 = q3 * q3;
-    float q3q4 = q3 * q4;
-    float q4q4 = q4 * q4;   
-
-    // Normalise accelerometer measurement
-    norm = sqrt(ax * ax + ay * ay + az * az);
-    if (norm == 0.0f) return; // handle NaN
-    norm = 1.0f / norm;        // use reciprocal for division
-    ax *= norm;
-    ay *= norm;
-    az *= norm;
-
-    // Normalise magnetometer measurement
-    norm = sqrt(mx * mx + my * my + mz * mz);
-    if (norm == 0.0f) return; // handle NaN
-    norm = 1.0f / norm;        // use reciprocal for division
-    mx *= norm;
-    my *= norm;
-    mz *= norm;
-
-    // Reference direction of Earth's magnetic field
-    hx = 2.0f * mx * (0.5f - q3q3 - q4q4) + 2.0f * my * (q2q3 - q1q4) + 2.0f * mz * (q2q4 + q1q3);
-    hy = 2.0f * mx * (q2q3 + q1q4) + 2.0f * my * (0.5f - q2q2 - q4q4) + 2.0f * mz * (q3q4 - q1q2);
-    bx = sqrt((hx * hx) + (hy * hy));
-    bz = 2.0f * mx * (q2q4 - q1q3) + 2.0f * my * (q3q4 + q1q2) + 2.0f * mz * (0.5f - q2q2 - q3q3);
-
-    // Estimated direction of gravity and magnetic field
-    vx = 2.0f * (q2q4 - q1q3);
-    vy = 2.0f * (q1q2 + q3q4);
-    vz = q1q1 - q2q2 - q3q3 + q4q4;
-    wx = 2.0f * bx * (0.5f - q3q3 - q4q4) + 2.0f * bz * (q2q4 - q1q3);
-    wy = 2.0f * bx * (q2q3 - q1q4) + 2.0f * bz * (q1q2 + q3q4);
-    wz = 2.0f * bx * (q1q3 + q2q4) + 2.0f * bz * (0.5f - q2q2 - q3q3);  
-
-    // Error is cross product between estimated direction and measured direction of gravity
-    ex = (ay * vz - az * vy) + (my * wz - mz * wy);
-    ey = (az * vx - ax * vz) + (mz * wx - mx * wz);
-    ez = (ax * vy - ay * vx) + (mx * wy - my * wx);
-    if (Ki > 0.0f){
-        eInt[0] += ex;      // accumulate integral error
-        eInt[1] += ey;
-        eInt[2] += ez;
-
-    }else{
-        eInt[0] = 0.0f;     // prevent integral wind up
-        eInt[1] = 0.0f;
-        eInt[2] = 0.0f;
-    }
-
-  // Apply feedback terms
-    gx = gx + Kp * ex + Ki * eInt[0];
-    gy = gy + Kp * ey + Ki * eInt[1];
-    gz = gz + Kp * ez + Ki * eInt[2];
-
-    // Integrate rate of change of quaternion
-    pa = q2;
-    pb = q3;
-    pc = q4;
-    q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * deltat);
-    q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * deltat);
-    q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * deltat);
-    q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * deltat);
-
-    // Normalise quaternion
-    norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);
-    norm = 1.0f / norm;
-    q[0] = q1 * norm;
-    q[1] = q2 * norm;
-    q[2] = q3 * norm;
-    q[3] = q4 * norm;
-
-}
-
-void MPU9250::translateQuaternionToDeg(float quaternion[4]){
-  yaw   = atan2(2.0f * (quaternion[1] * quaternion[2] + quaternion[0] * quaternion[3]), quaternion[0] * quaternion[0] + quaternion[1] * quaternion[1] - quaternion[2] * quaternion[2] - quaternion[3] * quaternion[3]);   
-  roll = -asin(2.0f * (quaternion[1] * quaternion[3] - quaternion[0] * quaternion[2]));
-  pitch  = atan2(2.0f * (quaternion[0] * quaternion[1] + quaternion[2] * quaternion[3]), quaternion[0] * quaternion[0] - quaternion[1] * quaternion[1] - quaternion[2] * quaternion[2] + quaternion[3] * quaternion[3]);
-}
-
-void MPU9250::calibrateDegree(void){
-    pitch *= 180.0f / PI;
-  yaw   *= 180.0f / PI; 
-  yaw   -= DECLINATION;
-  roll  *= 180.0f / PI; 
-}
-
-void MPU9250::transformCoordinateFromCompassToMPU(){
-    float buf = mx;
-    mx = my;
-    my = buf;
-    mz = -mz;
-}
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