Stephane Swanepoel / Mbed 2 deprecated mbed_multiplex_matrix

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Dependencies:   Matrix MatrixMath PCA9547 PowerControl mbed

Fork of mbed_multiplex by Stephane Swanepoel

MPU9250.h@0:80f939ca1f14, 2015-09-04 (annotated)

Committer:
yenzo
Date:
Fri Sep 04 21:37:38 2015 +0000
Revision:
0:80f939ca1f14
Child:
1:f0f34b17c4f0
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Who changed what in which revision?

UserRevisionLine numberNew contents of line
yenzo 0:80f939ca1f14 1 #include "DefineMPU.h"
yenzo 0:80f939ca1f14 2 #include "mbed.h"
yenzo 0:80f939ca1f14 3 #include "math.h"
yenzo 0:80f939ca1f14 4
yenzo 0:80f939ca1f14 5 #define Kp 3.0f * 5.0f // 2 - 5 these are the free parameters in the Mahony filter and fusion scheme, Kp for proportional feedback, Ki for integral
yenzo 0:80f939ca1f14 6 #define Ki 1.0f
yenzo 0:80f939ca1f14 7
yenzo 0:80f939ca1f14 8 class MPU9250 {
yenzo 0:80f939ca1f14 9 public :
yenzo 0:80f939ca1f14 10 int numero;
yenzo 0:80f939ca1f14 11
yenzo 0:80f939ca1f14 12 private:
yenzo 0:80f939ca1f14 13
yenzo 0:80f939ca1f14 14 static float Filter;
yenzo 0:80f939ca1f14 15
yenzo 0:80f939ca1f14 16 static float magCalibration[3]; // Factory mag calibration and mag bias
yenzo 0:80f939ca1f14 17 static float magbias[3]; // Factory mag calibration and mag bias
yenzo 0:80f939ca1f14 18
yenzo 0:80f939ca1f14 19 static float gyroBias[3]; // Bias corrections for gyro and accelerometer
yenzo 0:80f939ca1f14 20 static float accelBias[3]; // Bias corrections for gyro and accelerometer
yenzo 0:80f939ca1f14 21
yenzo 0:80f939ca1f14 22 int16_t accelCount[3]; // Stores the 16-bit signed accelerometer sensor output
yenzo 0:80f939ca1f14 23 int16_t gyroCount[3]; // Stores the 16-bit signed gyro sensor output
yenzo 0:80f939ca1f14 24 int16_t magCount[3]; // Stores the 16-bit signed magnetometer sensor output
yenzo 0:80f939ca1f14 25
yenzo 0:80f939ca1f14 26 int16_t tempCount; // Stores the real internal chip temperature in degrees Celsius
yenzo 0:80f939ca1f14 27 float temperature;
yenzo 0:80f939ca1f14 28 float SelfTest[6];
yenzo 0:80f939ca1f14 29
yenzo 0:80f939ca1f14 30 static float GyroMeasError; // gyroscope measurement error in rads/s (start at 60 deg/s), then reduce after ~10 s to 3
yenzo 0:80f939ca1f14 31 static float beta; // compute beta
yenzo 0:80f939ca1f14 32 static float GyroMeasDrift; // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
yenzo 0:80f939ca1f14 33 static float zeta; // compute zeta, the other free parameter in the Madgwick scheme usually set to a small or zero value
yenzo 0:80f939ca1f14 34
yenzo 0:80f939ca1f14 35 float pitch, yaw, roll;
yenzo 0:80f939ca1f14 36
yenzo 0:80f939ca1f14 37 static float q[4]; // vector to hold quaternion
yenzo 0:80f939ca1f14 38 static float eInt[3]; // vector to hold integral error for Mahony method
yenzo 0:80f939ca1f14 39
yenzo 0:80f939ca1f14 40 float aRes, gRes, mRes; // scale resolutions per LSB for the sensors
yenzo 0:80f939ca1f14 41 float ax, ay, az, gx, gy, gz, mx, my, mz; // variables to hold latest sensor data values
yenzo 0:80f939ca1f14 42
yenzo 0:80f939ca1f14 43 public:
yenzo 0:80f939ca1f14 44
yenzo 0:80f939ca1f14 45 //===================================================================================================================
yenzo 0:80f939ca1f14 46 //====== Set of useful function to access acceleratio, gyroscope, and temperature data
yenzo 0:80f939ca1f14 47 //===================================================================================================================
yenzo 0:80f939ca1f14 48
yenzo 0:80f939ca1f14 49 MPU9250() {}
yenzo 0:80f939ca1f14 50
yenzo 0:80f939ca1f14 51 MPU9250(int n){ numero = n; }
yenzo 0:80f939ca1f14 52
yenzo 0:80f939ca1f14 53 int GetPitch (void){ return (int)pitch; }
yenzo 0:80f939ca1f14 54 int GetRoll (void){ return (int)roll; }
yenzo 0:80f939ca1f14 55 int GetYaw (void){ return (int)yaw; }
yenzo 0:80f939ca1f14 56
yenzo 0:80f939ca1f14 57 void writeByte(uint8_t address, uint8_t subAddress, uint8_t data){
yenzo 0:80f939ca1f14 58 char data_write[2];
yenzo 0:80f939ca1f14 59 data_write[0] = subAddress;
yenzo 0:80f939ca1f14 60 data_write[1] = data;
yenzo 0:80f939ca1f14 61 i2c.write(address, data_write, 2, 0);
yenzo 0:80f939ca1f14 62 }
yenzo 0:80f939ca1f14 63
yenzo 0:80f939ca1f14 64 char readByte(uint8_t address, uint8_t subAddress){
yenzo 0:80f939ca1f14 65 char data[1];
yenzo 0:80f939ca1f14 66 char data_write[1];
yenzo 0:80f939ca1f14 67 data_write[0] = subAddress;
yenzo 0:80f939ca1f14 68 i2c.write(address, data_write, 1, 1);
yenzo 0:80f939ca1f14 69 i2c.read(address, data, 1, 0);
yenzo 0:80f939ca1f14 70 return data[0];
yenzo 0:80f939ca1f14 71 }
yenzo 0:80f939ca1f14 72
yenzo 0:80f939ca1f14 73 void readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest){
yenzo 0:80f939ca1f14 74 char data[14];
yenzo 0:80f939ca1f14 75 char data_write[1];
yenzo 0:80f939ca1f14 76 data_write[0] = subAddress;
yenzo 0:80f939ca1f14 77 i2c.write(address, data_write, 1, 1);
yenzo 0:80f939ca1f14 78 i2c.read(address, data, count, 0);
yenzo 0:80f939ca1f14 79 for(int ii = 0; ii < count; ii++) {
yenzo 0:80f939ca1f14 80 dest[ii] = data[ii];
yenzo 0:80f939ca1f14 81 }
yenzo 0:80f939ca1f14 82 }
yenzo 0:80f939ca1f14 83
yenzo 0:80f939ca1f14 84 void getMres() {
yenzo 0:80f939ca1f14 85 switch (Mscale){
yenzo 0:80f939ca1f14 86 case MFS_14BITS: mRes = 10.0*4219.0/8190.0; break;
yenzo 0:80f939ca1f14 87 case MFS_16BITS: mRes = 10.0*4219.0/32760.0; break;
yenzo 0:80f939ca1f14 88 }
yenzo 0:80f939ca1f14 89 }
yenzo 0:80f939ca1f14 90
yenzo 0:80f939ca1f14 91 void getGres() {
yenzo 0:80f939ca1f14 92 switch (Gscale){
yenzo 0:80f939ca1f14 93 case GFS_250DPS: gRes = 250.0/32768.0; break;
yenzo 0:80f939ca1f14 94 case GFS_500DPS: gRes = 500.0/32768.0; break;
yenzo 0:80f939ca1f14 95 case GFS_1000DPS: gRes = 1000.0/32768.0; break;
yenzo 0:80f939ca1f14 96 case GFS_2000DPS: gRes = 2000.0/32768.0; break;
yenzo 0:80f939ca1f14 97 }
yenzo 0:80f939ca1f14 98 }
yenzo 0:80f939ca1f14 99
yenzo 0:80f939ca1f14 100 void getAres() {
yenzo 0:80f939ca1f14 101 switch (Ascale){
yenzo 0:80f939ca1f14 102 case AFS_2G: aRes = 2.0/32768.0; break;
yenzo 0:80f939ca1f14 103 case AFS_4G: aRes = 4.0/32768.0; break;
yenzo 0:80f939ca1f14 104 case AFS_8G: aRes = 8.0/32768.0; break;
yenzo 0:80f939ca1f14 105 case AFS_16G: aRes = 16.0/32768.0; break;
yenzo 0:80f939ca1f14 106 }
yenzo 0:80f939ca1f14 107 }
yenzo 0:80f939ca1f14 108
yenzo 0:80f939ca1f14 109 void readAccelData(int16_t * destination){
yenzo 0:80f939ca1f14 110 uint8_t rawData[6]; // x/y/z accel register data stored here
yenzo 0:80f939ca1f14 111 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
yenzo 0:80f939ca1f14 112 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
yenzo 0:80f939ca1f14 113 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
yenzo 0:80f939ca1f14 114 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
yenzo 0:80f939ca1f14 115 }
yenzo 0:80f939ca1f14 116
yenzo 0:80f939ca1f14 117 void readGyroData(int16_t * destination){
yenzo 0:80f939ca1f14 118 uint8_t rawData[6]; // x/y/z gyro register data stored here
yenzo 0:80f939ca1f14 119 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
yenzo 0:80f939ca1f14 120 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
yenzo 0:80f939ca1f14 121 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
yenzo 0:80f939ca1f14 122 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
yenzo 0:80f939ca1f14 123 }
yenzo 0:80f939ca1f14 124
yenzo 0:80f939ca1f14 125 void readMagData(int16_t * destination){
yenzo 0:80f939ca1f14 126 uint8_t rawData[7]; // x/y/z gyro register data, ST2 register stored here, must read ST2 at end of data acquisition
yenzo 0:80f939ca1f14 127 if(readByte(AK8963_ADDRESS, AK8963_ST1) & 0x01) { // wait for magnetometer data ready bit to be set
yenzo 0:80f939ca1f14 128 readBytes(AK8963_ADDRESS, AK8963_XOUT_L, 7, &rawData[0]); // Read the six raw data and ST2 registers sequentially into data array
yenzo 0:80f939ca1f14 129 uint8_t c = rawData[6]; // End data read by reading ST2 register
yenzo 0:80f939ca1f14 130 if(!(c & 0x08)) { // Check if magnetic sensor overflow set, if not then report data
yenzo 0:80f939ca1f14 131 destination[0] = (int16_t)(((int16_t)rawData[1] << 8) | rawData[0]); // Turn the MSB and LSB into a signed 16-bit value
yenzo 0:80f939ca1f14 132 destination[1] = (int16_t)(((int16_t)rawData[3] << 8) | rawData[2]) ; // Data stored as little Endian
yenzo 0:80f939ca1f14 133 destination[2] = (int16_t)(((int16_t)rawData[5] << 8) | rawData[4]) ;
yenzo 0:80f939ca1f14 134 }
yenzo 0:80f939ca1f14 135 }
yenzo 0:80f939ca1f14 136 }
yenzo 0:80f939ca1f14 137
yenzo 0:80f939ca1f14 138 void resetMPU9250() { // reset device
yenzo 0:80f939ca1f14 139 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
yenzo 0:80f939ca1f14 140 wait(0.1);
yenzo 0:80f939ca1f14 141 }
yenzo 0:80f939ca1f14 142
yenzo 0:80f939ca1f14 143 void initAK8963(float * destination){ // First extract the factory calibration for each magnetometer axis
yenzo 0:80f939ca1f14 144 uint8_t rawData[3]; // x/y/z gyro calibration data stored here
yenzo 0:80f939ca1f14 145 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
yenzo 0:80f939ca1f14 146 wait(0.01);
yenzo 0:80f939ca1f14 147 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x0F); // Enter Fuse ROM access mode
yenzo 0:80f939ca1f14 148 wait(0.01);
yenzo 0:80f939ca1f14 149 readBytes(AK8963_ADDRESS, AK8963_ASAX, 3, &rawData[0]); // Read the x-, y-, and z-axis calibration values
yenzo 0:80f939ca1f14 150 destination[0] = (float)(rawData[0] - 128)/256.0f + 1.0f; // Return x-axis sensitivity adjustment values, etc.
yenzo 0:80f939ca1f14 151 destination[1] = (float)(rawData[1] - 128)/256.0f + 1.0f;
yenzo 0:80f939ca1f14 152 destination[2] = (float)(rawData[2] - 128)/256.0f + 1.0f;
yenzo 0:80f939ca1f14 153 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
yenzo 0:80f939ca1f14 154 wait(0.01);
yenzo 0:80f939ca1f14 155 writeByte(AK8963_ADDRESS, AK8963_CNTL, Mscale << 4 | Mmode); // Set magnetometer data resolution and sample ODR
yenzo 0:80f939ca1f14 156 wait(0.01);
yenzo 0:80f939ca1f14 157 }
yenzo 0:80f939ca1f14 158
yenzo 0:80f939ca1f14 159 void initMPU9250(){
yenzo 0:80f939ca1f14 160 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors
yenzo 0:80f939ca1f14 161 wait(0.1); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt
yenzo 0:80f939ca1f14 162
yenzo 0:80f939ca1f14 163 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01); // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
yenzo 0:80f939ca1f14 164 writeByte(MPU9250_ADDRESS, CONFIG, 0x03);
yenzo 0:80f939ca1f14 165
yenzo 0:80f939ca1f14 166 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x04); // Use a 200 Hz rate; the same rate set in CONFIG above
yenzo 0:80f939ca1f14 167
yenzo 0:80f939ca1f14 168 uint8_t c = readByte(MPU9250_ADDRESS, GYRO_CONFIG);
yenzo 0:80f939ca1f14 169 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
yenzo 0:80f939ca1f14 170 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
yenzo 0:80f939ca1f14 171 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c | Gscale << 3); // Set full scale range for the gyro
yenzo 0:80f939ca1f14 172
yenzo 0:80f939ca1f14 173 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG);
yenzo 0:80f939ca1f14 174 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
yenzo 0:80f939ca1f14 175 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
yenzo 0:80f939ca1f14 176 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c | Ascale << 3); // Set full scale range for the accelerometer
yenzo 0:80f939ca1f14 177
yenzo 0:80f939ca1f14 178 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG2);
yenzo 0:80f939ca1f14 179 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c & ~0x0F); // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0])
yenzo 0:80f939ca1f14 180 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c | 0x03); // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz
yenzo 0:80f939ca1f14 181
yenzo 0:80f939ca1f14 182 writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x22);
yenzo 0:80f939ca1f14 183 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt
yenzo 0:80f939ca1f14 184 }
yenzo 0:80f939ca1f14 185
yenzo 0:80f939ca1f14 186 void calibrateMPU9250(float * dest1, float * dest2){
yenzo 0:80f939ca1f14 187 uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data
yenzo 0:80f939ca1f14 188 uint16_t ii, packet_count, fifo_count;
yenzo 0:80f939ca1f14 189 int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
yenzo 0:80f939ca1f14 190
yenzo 0:80f939ca1f14 191 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
yenzo 0:80f939ca1f14 192 wait(0.1);
yenzo 0:80f939ca1f14 193
yenzo 0:80f939ca1f14 194 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01);
yenzo 0:80f939ca1f14 195 writeByte(MPU9250_ADDRESS, PWR_MGMT_2, 0x00);
yenzo 0:80f939ca1f14 196 wait(0.2);
yenzo 0:80f939ca1f14 197
yenzo 0:80f939ca1f14 198 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts
yenzo 0:80f939ca1f14 199 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable FIFO
yenzo 0:80f939ca1f14 200 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source
yenzo 0:80f939ca1f14 201 writeByte(MPU9250_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master
yenzo 0:80f939ca1f14 202 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes
yenzo 0:80f939ca1f14 203 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP
yenzo 0:80f939ca1f14 204 wait(0.015);
yenzo 0:80f939ca1f14 205
yenzo 0:80f939ca1f14 206 writeByte(MPU9250_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz
yenzo 0:80f939ca1f14 207 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz
yenzo 0:80f939ca1f14 208 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity
yenzo 0:80f939ca1f14 209 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity
yenzo 0:80f939ca1f14 210
yenzo 0:80f939ca1f14 211 uint16_t gyrosensitivity = 131; // = 131 LSB/degrees/sec
yenzo 0:80f939ca1f14 212 uint16_t accelsensitivity = 16384; // = 16384 LSB/g
yenzo 0:80f939ca1f14 213
yenzo 0:80f939ca1f14 214 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x40); // Enable FIFO
yenzo 0:80f939ca1f14 215 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9250)
yenzo 0:80f939ca1f14 216 wait(0.04); // accumulate 40 samples in 80 milliseconds = 480 bytes
yenzo 0:80f939ca1f14 217
yenzo 0:80f939ca1f14 218 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO
yenzo 0:80f939ca1f14 219 readBytes(MPU9250_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count
yenzo 0:80f939ca1f14 220 fifo_count = ((uint16_t)data[0] << 8) | data[1];
yenzo 0:80f939ca1f14 221 packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging
yenzo 0:80f939ca1f14 222
yenzo 0:80f939ca1f14 223 for (ii = 0; ii < packet_count; ii++) {
yenzo 0:80f939ca1f14 224 int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0};
yenzo 0:80f939ca1f14 225 readBytes(MPU9250_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging
yenzo 0:80f939ca1f14 226 accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO
yenzo 0:80f939ca1f14 227 accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ;
yenzo 0:80f939ca1f14 228 accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ;
yenzo 0:80f939ca1f14 229 gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ;
yenzo 0:80f939ca1f14 230 gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ;
yenzo 0:80f939ca1f14 231 gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ;
yenzo 0:80f939ca1f14 232
yenzo 0:80f939ca1f14 233 accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases
yenzo 0:80f939ca1f14 234 accel_bias[1] += (int32_t) accel_temp[1];
yenzo 0:80f939ca1f14 235 accel_bias[2] += (int32_t) accel_temp[2];
yenzo 0:80f939ca1f14 236 gyro_bias[0] += (int32_t) gyro_temp[0];
yenzo 0:80f939ca1f14 237 gyro_bias[1] += (int32_t) gyro_temp[1];
yenzo 0:80f939ca1f14 238 gyro_bias[2] += (int32_t) gyro_temp[2];
yenzo 0:80f939ca1f14 239 }
yenzo 0:80f939ca1f14 240
yenzo 0:80f939ca1f14 241 accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases
yenzo 0:80f939ca1f14 242 accel_bias[1] /= (int32_t) packet_count;
yenzo 0:80f939ca1f14 243 accel_bias[2] /= (int32_t) packet_count;
yenzo 0:80f939ca1f14 244 gyro_bias[0] /= (int32_t) packet_count;
yenzo 0:80f939ca1f14 245 gyro_bias[1] /= (int32_t) packet_count;
yenzo 0:80f939ca1f14 246 gyro_bias[2] /= (int32_t) packet_count;
yenzo 0:80f939ca1f14 247
yenzo 0:80f939ca1f14 248 if(accel_bias[2] > 0L) {accel_bias[2] -= (int32_t) accelsensitivity;} // Remove gravity from the z-axis accelerometer bias calculation
yenzo 0:80f939ca1f14 249 else {accel_bias[2] += (int32_t) accelsensitivity;}
yenzo 0:80f939ca1f14 250
yenzo 0:80f939ca1f14 251 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
yenzo 0:80f939ca1f14 252 data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
yenzo 0:80f939ca1f14 253 data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF;
yenzo 0:80f939ca1f14 254 data[3] = (-gyro_bias[1]/4) & 0xFF;
yenzo 0:80f939ca1f14 255 data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF;
yenzo 0:80f939ca1f14 256 data[5] = (-gyro_bias[2]/4) & 0xFF;
yenzo 0:80f939ca1f14 257
yenzo 0:80f939ca1f14 258 dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction
yenzo 0:80f939ca1f14 259 dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity;
yenzo 0:80f939ca1f14 260 dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity;
yenzo 0:80f939ca1f14 261
yenzo 0:80f939ca1f14 262 int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases
yenzo 0:80f939ca1f14 263 readBytes(MPU9250_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values
yenzo 0:80f939ca1f14 264 accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1];
yenzo 0:80f939ca1f14 265 readBytes(MPU9250_ADDRESS, YA_OFFSET_H, 2, &data[0]);
yenzo 0:80f939ca1f14 266 accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1];
yenzo 0:80f939ca1f14 267 readBytes(MPU9250_ADDRESS, ZA_OFFSET_H, 2, &data[0]);
yenzo 0:80f939ca1f14 268 accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1];
yenzo 0:80f939ca1f14 269
yenzo 0:80f939ca1f14 270 uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers
yenzo 0:80f939ca1f14 271 uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis
yenzo 0:80f939ca1f14 272
yenzo 0:80f939ca1f14 273 for(ii = 0; ii < 3; ii++) {
yenzo 0:80f939ca1f14 274 if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit
yenzo 0:80f939ca1f14 275 }
yenzo 0:80f939ca1f14 276
yenzo 0:80f939ca1f14 277 accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale)
yenzo 0:80f939ca1f14 278 accel_bias_reg[1] -= (accel_bias[1]/8);
yenzo 0:80f939ca1f14 279 accel_bias_reg[2] -= (accel_bias[2]/8);
yenzo 0:80f939ca1f14 280
yenzo 0:80f939ca1f14 281 data[0] = (accel_bias_reg[0] >> 8) & 0xFF;
yenzo 0:80f939ca1f14 282 data[1] = (accel_bias_reg[0]) & 0xFF;
yenzo 0:80f939ca1f14 283 data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers
yenzo 0:80f939ca1f14 284 data[2] = (accel_bias_reg[1] >> 8) & 0xFF;
yenzo 0:80f939ca1f14 285 data[3] = (accel_bias_reg[1]) & 0xFF;
yenzo 0:80f939ca1f14 286 data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers
yenzo 0:80f939ca1f14 287 data[4] = (accel_bias_reg[2] >> 8) & 0xFF;
yenzo 0:80f939ca1f14 288 data[5] = (accel_bias_reg[2]) & 0xFF;
yenzo 0:80f939ca1f14 289 data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers
yenzo 0:80f939ca1f14 290
yenzo 0:80f939ca1f14 291 dest2[0] = (float)accel_bias[0]/(float)accelsensitivity;
yenzo 0:80f939ca1f14 292 dest2[1] = (float)accel_bias[1]/(float)accelsensitivity;
yenzo 0:80f939ca1f14 293 dest2[2] = (float)accel_bias[2]/(float)accelsensitivity;
yenzo 0:80f939ca1f14 294 }
yenzo 0:80f939ca1f14 295
yenzo 0:80f939ca1f14 296 void MadgwickQuaternionUpdate(void){
yenzo 0:80f939ca1f14 297 //void MadgwickQuaternionUpdate(float deltat){
yenzo 0:80f939ca1f14 298
yenzo 0:80f939ca1f14 299 /*float tmp = mx;
yenzo 0:80f939ca1f14 300 mx = my;
yenzo 0:80f939ca1f14 301 my = tmp;
yenzo 0:80f939ca1f14 302 az = -az;*/
yenzo 0:80f939ca1f14 303
yenzo 0:80f939ca1f14 304 gx = gx*PI/180.0f;
yenzo 0:80f939ca1f14 305 gy = gy*PI/180.0f;
yenzo 0:80f939ca1f14 306 gz = gz*PI/180.0f;
yenzo 0:80f939ca1f14 307
yenzo 0:80f939ca1f14 308 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
yenzo 0:80f939ca1f14 309 float norm;
yenzo 0:80f939ca1f14 310 float hx, hy, _2bx, _2bz;
yenzo 0:80f939ca1f14 311 float s1, s2, s3, s4;
yenzo 0:80f939ca1f14 312 float qDot1, qDot2, qDot3, qDot4;
yenzo 0:80f939ca1f14 313
yenzo 0:80f939ca1f14 314 float _2q1mx;
yenzo 0:80f939ca1f14 315 float _2q1my;
yenzo 0:80f939ca1f14 316 float _2q1mz;
yenzo 0:80f939ca1f14 317 float _2q2mx;
yenzo 0:80f939ca1f14 318 float _4bx;
yenzo 0:80f939ca1f14 319 float _4bz;
yenzo 0:80f939ca1f14 320 float _2q1 = 2.0f * q1;
yenzo 0:80f939ca1f14 321 float _2q2 = 2.0f * q2;
yenzo 0:80f939ca1f14 322 float _2q3 = 2.0f * q3;
yenzo 0:80f939ca1f14 323 float _2q4 = 2.0f * q4;
yenzo 0:80f939ca1f14 324 float _2q1q3 = 2.0f * q1 * q3;
yenzo 0:80f939ca1f14 325 float _2q3q4 = 2.0f * q3 * q4;
yenzo 0:80f939ca1f14 326 float q1q1 = q1 * q1;
yenzo 0:80f939ca1f14 327 float q1q2 = q1 * q2;
yenzo 0:80f939ca1f14 328 float q1q3 = q1 * q3;
yenzo 0:80f939ca1f14 329 float q1q4 = q1 * q4;
yenzo 0:80f939ca1f14 330 float q2q2 = q2 * q2;
yenzo 0:80f939ca1f14 331 float q2q3 = q2 * q3;
yenzo 0:80f939ca1f14 332 float q2q4 = q2 * q4;
yenzo 0:80f939ca1f14 333 float q3q3 = q3 * q3;
yenzo 0:80f939ca1f14 334 float q3q4 = q3 * q4;
yenzo 0:80f939ca1f14 335 float q4q4 = q4 * q4;
yenzo 0:80f939ca1f14 336
yenzo 0:80f939ca1f14 337 norm = sqrt(ax * ax + ay * ay + az * az);
yenzo 0:80f939ca1f14 338 if (norm == 0.0f) return;
yenzo 0:80f939ca1f14 339 norm = 1.0f/norm;
yenzo 0:80f939ca1f14 340 ax *= norm;
yenzo 0:80f939ca1f14 341 ay *= norm;
yenzo 0:80f939ca1f14 342 az *= norm;
yenzo 0:80f939ca1f14 343
yenzo 0:80f939ca1f14 344 norm = sqrt(mx * mx + my * my + mz * mz);
yenzo 0:80f939ca1f14 345 if (norm == 0.0f) return;
yenzo 0:80f939ca1f14 346 norm = 1.0f/norm;
yenzo 0:80f939ca1f14 347 mx *= norm;
yenzo 0:80f939ca1f14 348 my *= norm;
yenzo 0:80f939ca1f14 349 mz *= norm;
yenzo 0:80f939ca1f14 350
yenzo 0:80f939ca1f14 351 _2q1mx = 2.0f * q1 * mx;
yenzo 0:80f939ca1f14 352 _2q1my = 2.0f * q1 * my;
yenzo 0:80f939ca1f14 353 _2q1mz = 2.0f * q1 * mz;
yenzo 0:80f939ca1f14 354 _2q2mx = 2.0f * q2 * mx;
yenzo 0:80f939ca1f14 355
yenzo 0:80f939ca1f14 356 hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4;
yenzo 0:80f939ca1f14 357 hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4;
yenzo 0:80f939ca1f14 358 _2bx = sqrt(hx * hx + hy * hy);
yenzo 0:80f939ca1f14 359 _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4;
yenzo 0:80f939ca1f14 360 _4bx = 2.0f * _2bx;
yenzo 0:80f939ca1f14 361 _4bz = 2.0f * _2bz;
yenzo 0:80f939ca1f14 362
yenzo 0:80f939ca1f14 363 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);
yenzo 0:80f939ca1f14 364 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);
yenzo 0:80f939ca1f14 365 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);
yenzo 0:80f939ca1f14 366 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);
yenzo 0:80f939ca1f14 367
yenzo 0:80f939ca1f14 368 norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4);
yenzo 0:80f939ca1f14 369 norm = 1.0f/norm;
yenzo 0:80f939ca1f14 370 s1 *= norm;
yenzo 0:80f939ca1f14 371 s2 *= norm;
yenzo 0:80f939ca1f14 372 s3 *= norm;
yenzo 0:80f939ca1f14 373 s4 *= norm;
yenzo 0:80f939ca1f14 374
yenzo 0:80f939ca1f14 375 qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1;
yenzo 0:80f939ca1f14 376 qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2;
yenzo 0:80f939ca1f14 377 qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3;
yenzo 0:80f939ca1f14 378 qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4;
yenzo 0:80f939ca1f14 379
yenzo 0:80f939ca1f14 380 /*q1 += qDot1 * deltat;
yenzo 0:80f939ca1f14 381 q2 += qDot2 * deltat;
yenzo 0:80f939ca1f14 382 q3 += qDot3 * deltat;
yenzo 0:80f939ca1f14 383 q4 += qDot4 * deltat;*/
yenzo 0:80f939ca1f14 384
yenzo 0:80f939ca1f14 385 q1 += qDot1 * Filter;
yenzo 0:80f939ca1f14 386 q2 += qDot2 * Filter;
yenzo 0:80f939ca1f14 387 q3 += qDot3 * Filter;
yenzo 0:80f939ca1f14 388 q4 += qDot4 * Filter;
yenzo 0:80f939ca1f14 389
yenzo 0:80f939ca1f14 390 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);
yenzo 0:80f939ca1f14 391 norm = 1.0f/norm;
yenzo 0:80f939ca1f14 392 q[0] = q1 * norm;
yenzo 0:80f939ca1f14 393 q[1] = q2 * norm;
yenzo 0:80f939ca1f14 394 q[2] = q3 * norm;
yenzo 0:80f939ca1f14 395 q[3] = q4 * norm;
yenzo 0:80f939ca1f14 396 }
yenzo 0:80f939ca1f14 397
yenzo 0:80f939ca1f14 398 int Float_to_Int(float numb){
yenzo 0:80f939ca1f14 399 float n = numb -(int)numb;
yenzo 0:80f939ca1f14 400 if(n >= 0 && n < 0.5) return (int)numb;
yenzo 0:80f939ca1f14 401 if(n >= 0.5 && n <= 1) return (int)numb + 1;
yenzo 0:80f939ca1f14 402 if(n <= 0 && n > -0.5) return (int)numb;
yenzo 0:80f939ca1f14 403 if(n <= -0.5 && n >= -1) return (int)numb - 1;
yenzo 0:80f939ca1f14 404 else return 0;
yenzo 0:80f939ca1f14 405 }
yenzo 0:80f939ca1f14 406
yenzo 0:80f939ca1f14 407 void CalibIMU(void){
yenzo 0:80f939ca1f14 408 wait(1);
yenzo 0:80f939ca1f14 409 resetMPU9250();
yenzo 0:80f939ca1f14 410 calibrateMPU9250(gyroBias, accelBias);
yenzo 0:80f939ca1f14 411 wait(2);
yenzo 0:80f939ca1f14 412 initMPU9250();
yenzo 0:80f939ca1f14 413 initAK8963(magCalibration);
yenzo 0:80f939ca1f14 414 wait(2);
yenzo 0:80f939ca1f14 415 }
yenzo 0:80f939ca1f14 416
yenzo 0:80f939ca1f14 417 void BiasIMU(void){
yenzo 0:80f939ca1f14 418 getAres();
yenzo 0:80f939ca1f14 419 getGres();
yenzo 0:80f939ca1f14 420 getMres();
yenzo 0:80f939ca1f14 421 magbias[0] = +470.;
yenzo 0:80f939ca1f14 422 magbias[1] = +120.;
yenzo 0:80f939ca1f14 423 magbias[2] = +125.;
yenzo 0:80f939ca1f14 424 }
yenzo 0:80f939ca1f14 425
yenzo 0:80f939ca1f14 426 void GetQuaternion(void){
yenzo 0:80f939ca1f14 427 readAccelData(accelCount);
yenzo 0:80f939ca1f14 428 ax = (float)accelCount[0]*aRes - accelBias[0];
yenzo 0:80f939ca1f14 429 ay = (float)accelCount[1]*aRes - accelBias[1];
yenzo 0:80f939ca1f14 430 az = (float)accelCount[2]*aRes - accelBias[2];
yenzo 0:80f939ca1f14 431
yenzo 0:80f939ca1f14 432 readGyroData(gyroCount);
yenzo 0:80f939ca1f14 433 gx = (float)gyroCount[0]*gRes - gyroBias[0];
yenzo 0:80f939ca1f14 434 gy = (float)gyroCount[1]*gRes - gyroBias[1];
yenzo 0:80f939ca1f14 435 gz = (float)gyroCount[2]*gRes - gyroBias[2];
yenzo 0:80f939ca1f14 436
yenzo 0:80f939ca1f14 437 readMagData(magCount);
yenzo 0:80f939ca1f14 438 mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0];
yenzo 0:80f939ca1f14 439 my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1];
yenzo 0:80f939ca1f14 440 mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2];
yenzo 0:80f939ca1f14 441 }
yenzo 0:80f939ca1f14 442
yenzo 0:80f939ca1f14 443 void FinalQuaternion(void){
yenzo 0:80f939ca1f14 444 yaw = atan2(2.0f * (q[1] * q[2] + q[0] * q[3]), q[0] * q[0] + q[1] * q[1] - q[2] * q[2] - q[3] * q[3]);
yenzo 0:80f939ca1f14 445 pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2]));
yenzo 0:80f939ca1f14 446 roll = atan2(2.0f * (q[0] * q[1] + q[2] * q[3]), q[0] * q[0] - q[1] * q[1] - q[2] * q[2] + q[3] * q[3]);
yenzo 0:80f939ca1f14 447 pitch *= 180.0f / PI;
yenzo 0:80f939ca1f14 448 yaw *= 180.0f / PI;
yenzo 0:80f939ca1f14 449 yaw -= 0.9f;
yenzo 0:80f939ca1f14 450 roll *= 180.0f / PI;
yenzo 0:80f939ca1f14 451
yenzo 0:80f939ca1f14 452 /*if((q[0]*q[1] + q[2]*q[3]) == 0.5){ //north pole
yenzo 0:80f939ca1f14 453 pitch = atan2(2*q[1]*q[3]-2*q[0]*q[2], 1 - 2*(q[1] * q[1]) - 2*(q[2] * q[2]));
yenzo 0:80f939ca1f14 454 yaw = atan2(2*q[0]*q[3]-2*q[1]*q[2], 1 - 2*(q[0] * q[0]) - 2*(q[2] * q[2]));
yenzo 0:80f939ca1f14 455 }
yenzo 0:80f939ca1f14 456 else{
yenzo 0:80f939ca1f14 457 pitch = 2.0 * atan2(q[0],q[4]);
yenzo 0:80f939ca1f14 458 yaw = 0;
yenzo 0:80f939ca1f14 459 }
yenzo 0:80f939ca1f14 460
yenzo 0:80f939ca1f14 461 if((q[0]*q[1] + q[2]*q[3]) == -0.5){ //south pole
yenzo 0:80f939ca1f14 462 pitch = atan2(2*q[1]*q[3]-2*q[0]*q[2], 1 - 2*(q[1] * q[1]) - 2*(q[2] * q[2]));
yenzo 0:80f939ca1f14 463 yaw = atan2(2*q[0]*q[3]-2*q[1]*q[2], 1 - 2*(q[0] * q[0]) - 2*(q[2] * q[2]));
yenzo 0:80f939ca1f14 464 }
yenzo 0:80f939ca1f14 465 else {
yenzo 0:80f939ca1f14 466 pitch = -2.0 * atan2(q[0],q[4]);
yenzo 0:80f939ca1f14 467 yaw = 0;
yenzo 0:80f939ca1f14 468 }
yenzo 0:80f939ca1f14 469 roll = asin(2*q[0]*q[1] + 2*q[2]*q[3]);*/
yenzo 0:80f939ca1f14 470
yenzo 0:80f939ca1f14 471
yenzo 0:80f939ca1f14 472
yenzo 0:80f939ca1f14 473 //if(roll < 180 & roll > 0) roll -= 180;
yenzo 0:80f939ca1f14 474 //else if(roll > -180 & roll < 0) roll += 180;
yenzo 0:80f939ca1f14 475
yenzo 0:80f939ca1f14 476 pitch = Float_to_Int(pitch);
yenzo 0:80f939ca1f14 477 roll = Float_to_Int(roll);
yenzo 0:80f939ca1f14 478 yaw = Float_to_Int(yaw);
yenzo 0:80f939ca1f14 479 }
yenzo 0:80f939ca1f14 480 };
yenzo 0:80f939ca1f14 481
yenzo 0:80f939ca1f14 482 //Definition des variables dans la Class MPU9250, car la definition ne peut pas être faite à l'intérieur
yenzo 0:80f939ca1f14 483 float MPU9250::gyroBias[3] = {0, 0, 0};
yenzo 0:80f939ca1f14 484 float MPU9250::accelBias[3] = {0, 0, 0}; // Bias corrections for gyro and accelerometer
yenzo 0:80f939ca1f14 485 float MPU9250::magCalibration[3] = {0, 0, 0};
yenzo 0:80f939ca1f14 486 float MPU9250::magbias[3] = {0, 0, 0};
yenzo 0:80f939ca1f14 487 float MPU9250::GyroMeasError = PI * (60.0f / 180.0f); // gyroscope measurement error in rads/s (start at 60 deg/s), then reduce after ~10 s to 3
yenzo 0:80f939ca1f14 488 float MPU9250::beta = sqrt(3.0f / 4.0f) * GyroMeasError; // compute beta
yenzo 0:80f939ca1f14 489 float MPU9250::GyroMeasDrift = PI * (1.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
yenzo 0:80f939ca1f14 490 float MPU9250::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
yenzo 0:80f939ca1f14 491 float MPU9250::q[4] = {1.0f, 0.0f, 0.0f, 0.0f}; // vector to hold quaternion
yenzo 0:80f939ca1f14 492 float MPU9250::eInt[3] = {0.0f, 0.0f, 0.0f}; // vector to hold integral error for Mahony method
yenzo 0:80f939ca1f14 493 float MPU9250::Filter = 0.05;