![](/media/cache/group/default_image.jpg.50x50_q85.jpg)
a
Dependencies: HCSR04_2 MPU6050_2 mbed SDFileSystem3
Fork of Autoflight2018_2 by
Diff: MPU9250/MPU9250.cpp
- Revision:
- 0:17f575135219
diff -r 000000000000 -r 17f575135219 MPU9250/MPU9250.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MPU9250/MPU9250.cpp Fri Sep 07 04:11:48 2018 +0000 @@ -0,0 +1,901 @@ +#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; +} \ No newline at end of file