Marco Mayer / Mbed OS Queue
Committer:
demayer
Date:
Sat Apr 11 08:15:48 2020 +0000
Revision:
1:b36bbc1c6d27
Child:
2:c7897a3f5f11
IMU-library in .h und .cpp file aufgeteilt

Who changed what in which revision?

UserRevisionLine numberNew contents of line
demayer 1:b36bbc1c6d27 1 #include "MPU9250.h"
demayer 1:b36bbc1c6d27 2
demayer 1:b36bbc1c6d27 3
demayer 1:b36bbc1c6d27 4
demayer 1:b36bbc1c6d27 5 uint8_t Ascale = AFS_2G; // AFS_2G, AFS_4G, AFS_8G, AFS_16G
demayer 1:b36bbc1c6d27 6 uint8_t Gscale = GFS_250DPS; // GFS_250DPS, GFS_500DPS, GFS_1000DPS, GFS_2000DPS
demayer 1:b36bbc1c6d27 7 uint8_t Mscale = MFS_16BITS; // MFS_14BITS or MFS_16BITS, 14-bit or 16-bit magnetometer resolution
demayer 1:b36bbc1c6d27 8 uint8_t Mmode = 0x06; // Either 8 Hz 0x02) or 100 Hz (0x06) magnetometer data ODR
demayer 1:b36bbc1c6d27 9 float aRes, gRes, mRes; // scale resolutions per LSB for the sensors
demayer 1:b36bbc1c6d27 10
demayer 1:b36bbc1c6d27 11 //Set up I2C, (SDA,SCL)
demayer 1:b36bbc1c6d27 12 I2C i2c(PB_9, PB_8);
demayer 1:b36bbc1c6d27 13
demayer 1:b36bbc1c6d27 14 DigitalOut myled(LED1);
demayer 1:b36bbc1c6d27 15
demayer 1:b36bbc1c6d27 16 // Pin definitions
demayer 1:b36bbc1c6d27 17 int intPin = 12; // These can be changed, 2 and 3 are the Arduinos ext int pins
demayer 1:b36bbc1c6d27 18
demayer 1:b36bbc1c6d27 19 int16_t accelCount[3]; // Stores the 16-bit signed accelerometer sensor output
demayer 1:b36bbc1c6d27 20 int16_t gyroCount[3]; // Stores the 16-bit signed gyro sensor output
demayer 1:b36bbc1c6d27 21 int16_t magCount[3]; // Stores the 16-bit signed magnetometer sensor output
demayer 1:b36bbc1c6d27 22 float magCalibration[3] = {0, 0, 0}, magbias[3] = {0, 0, 0}; // Factory mag calibration and mag bias
demayer 1:b36bbc1c6d27 23 float gyroBias[3] = {0, 0, 0}, accelBias[3] = {0, 0, 0}; // Bias corrections for gyro and accelerometer
demayer 1:b36bbc1c6d27 24 float ax, ay, az, gx, gy, gz, mx, my, mz; // variables to hold latest sensor data values
demayer 1:b36bbc1c6d27 25 int16_t tempCount; // Stores the real internal chip temperature in degrees Celsius
demayer 1:b36bbc1c6d27 26 float temperature;
demayer 1:b36bbc1c6d27 27 float SelfTest[6];
demayer 1:b36bbc1c6d27 28
demayer 1:b36bbc1c6d27 29 int delt_t = 0; // used to control display output rate
demayer 1:b36bbc1c6d27 30 int _count = 0; // used to control display output rate
demayer 1:b36bbc1c6d27 31
demayer 1:b36bbc1c6d27 32 // parameters for 6 DoF sensor fusion calculations
demayer 1:b36bbc1c6d27 33 float PI = 3.14159265358979323846f;
demayer 1:b36bbc1c6d27 34 float GyroMeasError = PI * (60.0f / 180.0f); // gyroscope measurement error in rads/s (start at 60 deg/s), then reduce after ~10 s to 3
demayer 1:b36bbc1c6d27 35 float beta = sqrt(3.0f / 4.0f) * GyroMeasError; // compute beta
demayer 1:b36bbc1c6d27 36 float GyroMeasDrift = PI * (1.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
demayer 1:b36bbc1c6d27 37 float 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
demayer 1:b36bbc1c6d27 38 #define Kp 2.0f * 5.0f // these are the free parameters in the Mahony filter and fusion scheme, Kp for proportional feedback, Ki for integral
demayer 1:b36bbc1c6d27 39 #define Ki 0.0f
demayer 1:b36bbc1c6d27 40
demayer 1:b36bbc1c6d27 41 float pitch, yaw, roll;
demayer 1:b36bbc1c6d27 42 float vx, vy, vz;
demayer 1:b36bbc1c6d27 43 float deltat = 0.0f; // integration interval for both filter schemes
demayer 1:b36bbc1c6d27 44 int lastUpdate = 0, firstUpdate = 0, Now = 0; // used to calculate integration interval // used to calculate integration interval
demayer 1:b36bbc1c6d27 45 float q[4] = {1.0f, 0.0f, 0.0f, 0.0f}; // vector to hold quaternion
demayer 1:b36bbc1c6d27 46 float v_trans[3] = {0.0f, 0.0f, 0.0f}; // vector to hold translative velocities
demayer 1:b36bbc1c6d27 47 float a_old[3] = {0.00f, 0.00f, 0.00f};
demayer 1:b36bbc1c6d27 48 float eInt[3] = {0.0f, 0.0f, 0.0f}; // vector to hold integral error for Mahony method
demayer 1:b36bbc1c6d27 49
demayer 1:b36bbc1c6d27 50
demayer 1:b36bbc1c6d27 51 accData_t myData;
demayer 1:b36bbc1c6d27 52 MPU9250 mpu9250;
demayer 1:b36bbc1c6d27 53 Timer t;
demayer 1:b36bbc1c6d27 54 Serial pc(USBTX, USBRX); // tx, rx
demayer 1:b36bbc1c6d27 55
demayer 1:b36bbc1c6d27 56 #define SAMPLE_TIME 100
demayer 1:b36bbc1c6d27 57
demayer 1:b36bbc1c6d27 58
demayer 1:b36bbc1c6d27 59 float sum = 0;
demayer 1:b36bbc1c6d27 60 uint32_t sumCount = 0;
demayer 1:b36bbc1c6d27 61 char buffer[14];
demayer 1:b36bbc1c6d27 62
demayer 1:b36bbc1c6d27 63
demayer 1:b36bbc1c6d27 64 //===================================================================================================================
demayer 1:b36bbc1c6d27 65 //====== Set of useful function to access acceleratio, gyroscope, and temperature data
demayer 1:b36bbc1c6d27 66 //===================================================================================================================
demayer 1:b36bbc1c6d27 67
demayer 1:b36bbc1c6d27 68 void MPU9250::writeByte(uint8_t address, uint8_t subAddress, uint8_t data)
demayer 1:b36bbc1c6d27 69 {
demayer 1:b36bbc1c6d27 70 char data_write[2];
demayer 1:b36bbc1c6d27 71 data_write[0] = subAddress;
demayer 1:b36bbc1c6d27 72 data_write[1] = data;
demayer 1:b36bbc1c6d27 73 i2c.write(address, data_write, 2, 0);
demayer 1:b36bbc1c6d27 74 }
demayer 1:b36bbc1c6d27 75
demayer 1:b36bbc1c6d27 76 char MPU9250::readByte(uint8_t address, uint8_t subAddress)
demayer 1:b36bbc1c6d27 77 {
demayer 1:b36bbc1c6d27 78 char data[1]; // `data` will store the register data
demayer 1:b36bbc1c6d27 79 char data_write[1];
demayer 1:b36bbc1c6d27 80 data_write[0] = subAddress;
demayer 1:b36bbc1c6d27 81 i2c.write(address, data_write, 1, 1); // no stop
demayer 1:b36bbc1c6d27 82 i2c.read(address, data, 1, 0);
demayer 1:b36bbc1c6d27 83 return data[0];
demayer 1:b36bbc1c6d27 84 }
demayer 1:b36bbc1c6d27 85
demayer 1:b36bbc1c6d27 86 void MPU9250::readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest)
demayer 1:b36bbc1c6d27 87 {
demayer 1:b36bbc1c6d27 88 char data[14];
demayer 1:b36bbc1c6d27 89 char data_write[1];
demayer 1:b36bbc1c6d27 90 data_write[0] = subAddress;
demayer 1:b36bbc1c6d27 91 i2c.write(address, data_write, 1, 1); // no stop
demayer 1:b36bbc1c6d27 92 i2c.read(address, data, count, 0);
demayer 1:b36bbc1c6d27 93 for(int ii = 0; ii < count; ii++) {
demayer 1:b36bbc1c6d27 94 dest[ii] = data[ii];
demayer 1:b36bbc1c6d27 95 }
demayer 1:b36bbc1c6d27 96 }
demayer 1:b36bbc1c6d27 97
demayer 1:b36bbc1c6d27 98
demayer 1:b36bbc1c6d27 99 void MPU9250::getMres()
demayer 1:b36bbc1c6d27 100 {
demayer 1:b36bbc1c6d27 101 switch (Mscale) {
demayer 1:b36bbc1c6d27 102 // Possible magnetometer scales (and their register bit settings) are:
demayer 1:b36bbc1c6d27 103 // 14 bit resolution (0) and 16 bit resolution (1)
demayer 1:b36bbc1c6d27 104 case MFS_14BITS:
demayer 1:b36bbc1c6d27 105 mRes = 10.0*4219.0/8190.0; // Proper scale to return milliGauss
demayer 1:b36bbc1c6d27 106 break;
demayer 1:b36bbc1c6d27 107 case MFS_16BITS:
demayer 1:b36bbc1c6d27 108 mRes = 10.0*4219.0/32760.0; // Proper scale to return milliGauss
demayer 1:b36bbc1c6d27 109 break;
demayer 1:b36bbc1c6d27 110 }
demayer 1:b36bbc1c6d27 111 }
demayer 1:b36bbc1c6d27 112
demayer 1:b36bbc1c6d27 113
demayer 1:b36bbc1c6d27 114 void MPU9250::getGres()
demayer 1:b36bbc1c6d27 115 {
demayer 1:b36bbc1c6d27 116 switch (Gscale) {
demayer 1:b36bbc1c6d27 117 // Possible gyro scales (and their register bit settings) are:
demayer 1:b36bbc1c6d27 118 // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS (11).
demayer 1:b36bbc1c6d27 119 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
demayer 1:b36bbc1c6d27 120 case GFS_250DPS:
demayer 1:b36bbc1c6d27 121 gRes = 250.0/32768.0;
demayer 1:b36bbc1c6d27 122 break;
demayer 1:b36bbc1c6d27 123 case GFS_500DPS:
demayer 1:b36bbc1c6d27 124 gRes = 500.0/32768.0;
demayer 1:b36bbc1c6d27 125 break;
demayer 1:b36bbc1c6d27 126 case GFS_1000DPS:
demayer 1:b36bbc1c6d27 127 gRes = 1000.0/32768.0;
demayer 1:b36bbc1c6d27 128 break;
demayer 1:b36bbc1c6d27 129 case GFS_2000DPS:
demayer 1:b36bbc1c6d27 130 gRes = 2000.0/32768.0;
demayer 1:b36bbc1c6d27 131 break;
demayer 1:b36bbc1c6d27 132 }
demayer 1:b36bbc1c6d27 133 }
demayer 1:b36bbc1c6d27 134
demayer 1:b36bbc1c6d27 135
demayer 1:b36bbc1c6d27 136 void MPU9250::getAres()
demayer 1:b36bbc1c6d27 137 {
demayer 1:b36bbc1c6d27 138 switch (Ascale) {
demayer 1:b36bbc1c6d27 139 // Possible accelerometer scales (and their register bit settings) are:
demayer 1:b36bbc1c6d27 140 // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs (11).
demayer 1:b36bbc1c6d27 141 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
demayer 1:b36bbc1c6d27 142 case AFS_2G:
demayer 1:b36bbc1c6d27 143 aRes = 2.0/32768.0;
demayer 1:b36bbc1c6d27 144 break;
demayer 1:b36bbc1c6d27 145 case AFS_4G:
demayer 1:b36bbc1c6d27 146 aRes = 4.0/32768.0;
demayer 1:b36bbc1c6d27 147 break;
demayer 1:b36bbc1c6d27 148 case AFS_8G:
demayer 1:b36bbc1c6d27 149 aRes = 8.0/32768.0;
demayer 1:b36bbc1c6d27 150 break;
demayer 1:b36bbc1c6d27 151 case AFS_16G:
demayer 1:b36bbc1c6d27 152 aRes = 16.0/32768.0;
demayer 1:b36bbc1c6d27 153 break;
demayer 1:b36bbc1c6d27 154 }
demayer 1:b36bbc1c6d27 155 }
demayer 1:b36bbc1c6d27 156
demayer 1:b36bbc1c6d27 157
demayer 1:b36bbc1c6d27 158 void MPU9250::readAccelData(int16_t * destination)
demayer 1:b36bbc1c6d27 159 {
demayer 1:b36bbc1c6d27 160 uint8_t rawData[6]; // x/y/z accel register data stored here
demayer 1:b36bbc1c6d27 161 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
demayer 1:b36bbc1c6d27 162 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 163 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 1:b36bbc1c6d27 164 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 1:b36bbc1c6d27 165 }
demayer 1:b36bbc1c6d27 166
demayer 1:b36bbc1c6d27 167 void MPU9250::readGyroData(int16_t * destination)
demayer 1:b36bbc1c6d27 168 {
demayer 1:b36bbc1c6d27 169 uint8_t rawData[6]; // x/y/z gyro register data stored here
demayer 1:b36bbc1c6d27 170 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
demayer 1:b36bbc1c6d27 171 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 172 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 1:b36bbc1c6d27 173 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 1:b36bbc1c6d27 174 }
demayer 1:b36bbc1c6d27 175
demayer 1:b36bbc1c6d27 176 void MPU9250::readMagData(int16_t * destination)
demayer 1:b36bbc1c6d27 177 {
demayer 1:b36bbc1c6d27 178 uint8_t rawData[7]; // x/y/z gyro register data, ST2 register stored here, must read ST2 at end of data acquisition
demayer 1:b36bbc1c6d27 179 if(readByte(AK8963_ADDRESS, AK8963_ST1) & 0x01) { // wait for magnetometer data ready bit to be set
demayer 1:b36bbc1c6d27 180 readBytes(AK8963_ADDRESS, AK8963_XOUT_L, 7, &rawData[0]); // Read the six raw data and ST2 registers sequentially into data array
demayer 1:b36bbc1c6d27 181 uint8_t c = rawData[6]; // End data read by reading ST2 register
demayer 1:b36bbc1c6d27 182 if(!(c & 0x08)) { // Check if magnetic sensor overflow set, if not then report data
demayer 1:b36bbc1c6d27 183 destination[0] = (int16_t)(((int16_t)rawData[1] << 8) | rawData[0]); // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 184 destination[1] = (int16_t)(((int16_t)rawData[3] << 8) | rawData[2]) ; // Data stored as little Endian
demayer 1:b36bbc1c6d27 185 destination[2] = (int16_t)(((int16_t)rawData[5] << 8) | rawData[4]) ;
demayer 1:b36bbc1c6d27 186 }
demayer 1:b36bbc1c6d27 187 }
demayer 1:b36bbc1c6d27 188 }
demayer 1:b36bbc1c6d27 189
demayer 1:b36bbc1c6d27 190 int16_t MPU9250::readTempData()
demayer 1:b36bbc1c6d27 191 {
demayer 1:b36bbc1c6d27 192 uint8_t rawData[2]; // x/y/z gyro register data stored here
demayer 1:b36bbc1c6d27 193 readBytes(MPU9250_ADDRESS, TEMP_OUT_H, 2, &rawData[0]); // Read the two raw data registers sequentially into data array
demayer 1:b36bbc1c6d27 194 return (int16_t)(((int16_t)rawData[0]) << 8 | rawData[1]) ; // Turn the MSB and LSB into a 16-bit value
demayer 1:b36bbc1c6d27 195 }
demayer 1:b36bbc1c6d27 196
demayer 1:b36bbc1c6d27 197
demayer 1:b36bbc1c6d27 198 void MPU9250::resetMPU9250()
demayer 1:b36bbc1c6d27 199 {
demayer 1:b36bbc1c6d27 200 // reset device
demayer 1:b36bbc1c6d27 201 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
demayer 1:b36bbc1c6d27 202 wait(0.1);
demayer 1:b36bbc1c6d27 203 }
demayer 1:b36bbc1c6d27 204
demayer 1:b36bbc1c6d27 205 void MPU9250::initAK8963(float * destination)
demayer 1:b36bbc1c6d27 206 {
demayer 1:b36bbc1c6d27 207 // First extract the factory calibration for each magnetometer axis
demayer 1:b36bbc1c6d27 208 uint8_t rawData[3]; // x/y/z gyro calibration data stored here
demayer 1:b36bbc1c6d27 209 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
demayer 1:b36bbc1c6d27 210 wait(0.01);
demayer 1:b36bbc1c6d27 211 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x0F); // Enter Fuse ROM access mode
demayer 1:b36bbc1c6d27 212 wait(0.01);
demayer 1:b36bbc1c6d27 213 readBytes(AK8963_ADDRESS, AK8963_ASAX, 3, &rawData[0]); // Read the x-, y-, and z-axis calibration values
demayer 1:b36bbc1c6d27 214 destination[0] = (float)(rawData[0] - 128)/256.0f + 1.0f; // Return x-axis sensitivity adjustment values, etc.
demayer 1:b36bbc1c6d27 215 destination[1] = (float)(rawData[1] - 128)/256.0f + 1.0f;
demayer 1:b36bbc1c6d27 216 destination[2] = (float)(rawData[2] - 128)/256.0f + 1.0f;
demayer 1:b36bbc1c6d27 217 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
demayer 1:b36bbc1c6d27 218 wait(0.01);
demayer 1:b36bbc1c6d27 219 // Configure the magnetometer for continuous read and highest resolution
demayer 1:b36bbc1c6d27 220 // set Mscale bit 4 to 1 (0) to enable 16 (14) bit resolution in CNTL register,
demayer 1:b36bbc1c6d27 221 // and enable continuous mode data acquisition Mmode (bits [3:0]), 0010 for 8 Hz and 0110 for 100 Hz sample rates
demayer 1:b36bbc1c6d27 222 writeByte(AK8963_ADDRESS, AK8963_CNTL, Mscale << 4 | Mmode); // Set magnetometer data resolution and sample ODR
demayer 1:b36bbc1c6d27 223 wait(0.01);
demayer 1:b36bbc1c6d27 224 }
demayer 1:b36bbc1c6d27 225
demayer 1:b36bbc1c6d27 226
demayer 1:b36bbc1c6d27 227 void MPU9250::initMPU9250()
demayer 1:b36bbc1c6d27 228 {
demayer 1:b36bbc1c6d27 229 // Initialize MPU9250 device
demayer 1:b36bbc1c6d27 230 // wake up device
demayer 1:b36bbc1c6d27 231 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors
demayer 1:b36bbc1c6d27 232 wait(0.1); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt
demayer 1:b36bbc1c6d27 233
demayer 1:b36bbc1c6d27 234 // get stable time source
demayer 1:b36bbc1c6d27 235 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01); // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
demayer 1:b36bbc1c6d27 236
demayer 1:b36bbc1c6d27 237 // Configure Gyro and Accelerometer
demayer 1:b36bbc1c6d27 238 // Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively;
demayer 1:b36bbc1c6d27 239 // DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both
demayer 1:b36bbc1c6d27 240 // Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate
demayer 1:b36bbc1c6d27 241 writeByte(MPU9250_ADDRESS, CONFIG, 0x03);
demayer 1:b36bbc1c6d27 242
demayer 1:b36bbc1c6d27 243 // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV)
demayer 1:b36bbc1c6d27 244 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x04); // Use a 200 Hz rate; the same rate set in CONFIG above
demayer 1:b36bbc1c6d27 245
demayer 1:b36bbc1c6d27 246 // Set gyroscope full scale range
demayer 1:b36bbc1c6d27 247 // Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3
demayer 1:b36bbc1c6d27 248 uint8_t c = readByte(MPU9250_ADDRESS, GYRO_CONFIG);
demayer 1:b36bbc1c6d27 249 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
demayer 1:b36bbc1c6d27 250 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
demayer 1:b36bbc1c6d27 251 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c | Gscale << 3); // Set full scale range for the gyro
demayer 1:b36bbc1c6d27 252
demayer 1:b36bbc1c6d27 253 // Set accelerometer configuration
demayer 1:b36bbc1c6d27 254 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG);
demayer 1:b36bbc1c6d27 255 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
demayer 1:b36bbc1c6d27 256 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
demayer 1:b36bbc1c6d27 257 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c | Ascale << 3); // Set full scale range for the accelerometer
demayer 1:b36bbc1c6d27 258
demayer 1:b36bbc1c6d27 259 // Set accelerometer sample rate configuration
demayer 1:b36bbc1c6d27 260 // It is possible to get a 4 kHz sample rate from the accelerometer by choosing 1 for
demayer 1:b36bbc1c6d27 261 // accel_fchoice_b bit [3]; in this case the bandwidth is 1.13 kHz
demayer 1:b36bbc1c6d27 262 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG2);
demayer 1:b36bbc1c6d27 263 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c & ~0x0F); // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0])
demayer 1:b36bbc1c6d27 264 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c | 0x03); // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz
demayer 1:b36bbc1c6d27 265
demayer 1:b36bbc1c6d27 266 // The accelerometer, gyro, and thermometer are set to 1 kHz sample rates,
demayer 1:b36bbc1c6d27 267 // but all these rates are further reduced by a factor of 5 to 200 Hz because of the SMPLRT_DIV setting
demayer 1:b36bbc1c6d27 268
demayer 1:b36bbc1c6d27 269 // Configure Interrupts and Bypass Enable
demayer 1:b36bbc1c6d27 270 // Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips
demayer 1:b36bbc1c6d27 271 // can join the I2C bus and all can be controlled by the Arduino as master
demayer 1:b36bbc1c6d27 272 writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x22);
demayer 1:b36bbc1c6d27 273 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt
demayer 1:b36bbc1c6d27 274 }
demayer 1:b36bbc1c6d27 275
demayer 1:b36bbc1c6d27 276 // Function which accumulates gyro and accelerometer data after device initialization. It calculates the average
demayer 1:b36bbc1c6d27 277 // of the at-rest readings and then loads the resulting offsets into accelerometer and gyro bias registers.
demayer 1:b36bbc1c6d27 278 void MPU9250::calibrateMPU9250(float * dest1, float * dest2)
demayer 1:b36bbc1c6d27 279 {
demayer 1:b36bbc1c6d27 280 uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data
demayer 1:b36bbc1c6d27 281 uint16_t ii, packet_count, fifo_count;
demayer 1:b36bbc1c6d27 282 int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
demayer 1:b36bbc1c6d27 283
demayer 1:b36bbc1c6d27 284 // reset device, reset all registers, clear gyro and accelerometer bias registers
demayer 1:b36bbc1c6d27 285 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
demayer 1:b36bbc1c6d27 286 wait(0.1);
demayer 1:b36bbc1c6d27 287
demayer 1:b36bbc1c6d27 288 // get stable time source
demayer 1:b36bbc1c6d27 289 // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
demayer 1:b36bbc1c6d27 290 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01);
demayer 1:b36bbc1c6d27 291 writeByte(MPU9250_ADDRESS, PWR_MGMT_2, 0x00);
demayer 1:b36bbc1c6d27 292 wait(0.2);
demayer 1:b36bbc1c6d27 293
demayer 1:b36bbc1c6d27 294 // Configure device for bias calculation
demayer 1:b36bbc1c6d27 295 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts
demayer 1:b36bbc1c6d27 296 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable FIFO
demayer 1:b36bbc1c6d27 297 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source
demayer 1:b36bbc1c6d27 298 writeByte(MPU9250_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master
demayer 1:b36bbc1c6d27 299 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes
demayer 1:b36bbc1c6d27 300 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP
demayer 1:b36bbc1c6d27 301 wait(0.015);
demayer 1:b36bbc1c6d27 302
demayer 1:b36bbc1c6d27 303 // Configure MPU9250 gyro and accelerometer for bias calculation
demayer 1:b36bbc1c6d27 304 writeByte(MPU9250_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz
demayer 1:b36bbc1c6d27 305 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz
demayer 1:b36bbc1c6d27 306 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity
demayer 1:b36bbc1c6d27 307 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity
demayer 1:b36bbc1c6d27 308
demayer 1:b36bbc1c6d27 309 uint16_t gyrosensitivity = 131; // = 131 LSB/degrees/sec
demayer 1:b36bbc1c6d27 310 uint16_t accelsensitivity = 16384; // = 16384 LSB/g
demayer 1:b36bbc1c6d27 311
demayer 1:b36bbc1c6d27 312 // Configure FIFO to capture accelerometer and gyro data for bias calculation
demayer 1:b36bbc1c6d27 313 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x40); // Enable FIFO
demayer 1:b36bbc1c6d27 314 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9250)
demayer 1:b36bbc1c6d27 315 wait(0.04); // accumulate 40 samples in 80 milliseconds = 480 bytes
demayer 1:b36bbc1c6d27 316
demayer 1:b36bbc1c6d27 317 // At end of sample accumulation, turn off FIFO sensor read
demayer 1:b36bbc1c6d27 318 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO
demayer 1:b36bbc1c6d27 319 readBytes(MPU9250_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count
demayer 1:b36bbc1c6d27 320 fifo_count = ((uint16_t)data[0] << 8) | data[1];
demayer 1:b36bbc1c6d27 321 packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging
demayer 1:b36bbc1c6d27 322
demayer 1:b36bbc1c6d27 323 for (ii = 0; ii < packet_count; ii++) {
demayer 1:b36bbc1c6d27 324 int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0};
demayer 1:b36bbc1c6d27 325 readBytes(MPU9250_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging
demayer 1:b36bbc1c6d27 326 accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO
demayer 1:b36bbc1c6d27 327 accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ;
demayer 1:b36bbc1c6d27 328 accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ;
demayer 1:b36bbc1c6d27 329 gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ;
demayer 1:b36bbc1c6d27 330 gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ;
demayer 1:b36bbc1c6d27 331 gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ;
demayer 1:b36bbc1c6d27 332
demayer 1:b36bbc1c6d27 333 accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases
demayer 1:b36bbc1c6d27 334 accel_bias[1] += (int32_t) accel_temp[1];
demayer 1:b36bbc1c6d27 335 accel_bias[2] += (int32_t) accel_temp[2];
demayer 1:b36bbc1c6d27 336 gyro_bias[0] += (int32_t) gyro_temp[0];
demayer 1:b36bbc1c6d27 337 gyro_bias[1] += (int32_t) gyro_temp[1];
demayer 1:b36bbc1c6d27 338 gyro_bias[2] += (int32_t) gyro_temp[2];
demayer 1:b36bbc1c6d27 339
demayer 1:b36bbc1c6d27 340 }
demayer 1:b36bbc1c6d27 341 accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases
demayer 1:b36bbc1c6d27 342 accel_bias[1] /= (int32_t) packet_count;
demayer 1:b36bbc1c6d27 343 accel_bias[2] /= (int32_t) packet_count;
demayer 1:b36bbc1c6d27 344 gyro_bias[0] /= (int32_t) packet_count;
demayer 1:b36bbc1c6d27 345 gyro_bias[1] /= (int32_t) packet_count;
demayer 1:b36bbc1c6d27 346 gyro_bias[2] /= (int32_t) packet_count;
demayer 1:b36bbc1c6d27 347
demayer 1:b36bbc1c6d27 348 if(accel_bias[2] > 0L) {
demayer 1:b36bbc1c6d27 349 accel_bias[2] -= (int32_t) accelsensitivity; // Remove gravity from the z-axis accelerometer bias calculation
demayer 1:b36bbc1c6d27 350 } else {
demayer 1:b36bbc1c6d27 351 accel_bias[2] += (int32_t) accelsensitivity;
demayer 1:b36bbc1c6d27 352 }
demayer 1:b36bbc1c6d27 353
demayer 1:b36bbc1c6d27 354 // Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup
demayer 1:b36bbc1c6d27 355 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
demayer 1:b36bbc1c6d27 356 data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
demayer 1:b36bbc1c6d27 357 data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF;
demayer 1:b36bbc1c6d27 358 data[3] = (-gyro_bias[1]/4) & 0xFF;
demayer 1:b36bbc1c6d27 359 data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF;
demayer 1:b36bbc1c6d27 360 data[5] = (-gyro_bias[2]/4) & 0xFF;
demayer 1:b36bbc1c6d27 361
demayer 1:b36bbc1c6d27 362 /// Push gyro biases to hardware registers
demayer 1:b36bbc1c6d27 363 /* writeByte(MPU9250_ADDRESS, XG_OFFSET_H, data[0]);
demayer 1:b36bbc1c6d27 364 writeByte(MPU9250_ADDRESS, XG_OFFSET_L, data[1]);
demayer 1:b36bbc1c6d27 365 writeByte(MPU9250_ADDRESS, YG_OFFSET_H, data[2]);
demayer 1:b36bbc1c6d27 366 writeByte(MPU9250_ADDRESS, YG_OFFSET_L, data[3]);
demayer 1:b36bbc1c6d27 367 writeByte(MPU9250_ADDRESS, ZG_OFFSET_H, data[4]);
demayer 1:b36bbc1c6d27 368 writeByte(MPU9250_ADDRESS, ZG_OFFSET_L, data[5]);
demayer 1:b36bbc1c6d27 369 */
demayer 1:b36bbc1c6d27 370 dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction
demayer 1:b36bbc1c6d27 371 dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity;
demayer 1:b36bbc1c6d27 372 dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity;
demayer 1:b36bbc1c6d27 373
demayer 1:b36bbc1c6d27 374 // Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain
demayer 1:b36bbc1c6d27 375 // factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold
demayer 1:b36bbc1c6d27 376 // non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature
demayer 1:b36bbc1c6d27 377 // compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that
demayer 1:b36bbc1c6d27 378 // the accelerometer biases calculated above must be divided by 8.
demayer 1:b36bbc1c6d27 379
demayer 1:b36bbc1c6d27 380 int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases
demayer 1:b36bbc1c6d27 381 readBytes(MPU9250_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values
demayer 1:b36bbc1c6d27 382 accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1];
demayer 1:b36bbc1c6d27 383 readBytes(MPU9250_ADDRESS, YA_OFFSET_H, 2, &data[0]);
demayer 1:b36bbc1c6d27 384 accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1];
demayer 1:b36bbc1c6d27 385 readBytes(MPU9250_ADDRESS, ZA_OFFSET_H, 2, &data[0]);
demayer 1:b36bbc1c6d27 386 accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1];
demayer 1:b36bbc1c6d27 387
demayer 1:b36bbc1c6d27 388 uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers
demayer 1:b36bbc1c6d27 389 uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis
demayer 1:b36bbc1c6d27 390
demayer 1:b36bbc1c6d27 391 for(ii = 0; ii < 3; ii++) {
demayer 1:b36bbc1c6d27 392 if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit
demayer 1:b36bbc1c6d27 393 }
demayer 1:b36bbc1c6d27 394
demayer 1:b36bbc1c6d27 395 // Construct total accelerometer bias, including calculated average accelerometer bias from above
demayer 1:b36bbc1c6d27 396 accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale)
demayer 1:b36bbc1c6d27 397 accel_bias_reg[1] -= (accel_bias[1]/8);
demayer 1:b36bbc1c6d27 398 accel_bias_reg[2] -= (accel_bias[2]/8);
demayer 1:b36bbc1c6d27 399
demayer 1:b36bbc1c6d27 400 data[0] = (accel_bias_reg[0] >> 8) & 0xFF;
demayer 1:b36bbc1c6d27 401 data[1] = (accel_bias_reg[0]) & 0xFF;
demayer 1:b36bbc1c6d27 402 data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers
demayer 1:b36bbc1c6d27 403 data[2] = (accel_bias_reg[1] >> 8) & 0xFF;
demayer 1:b36bbc1c6d27 404 data[3] = (accel_bias_reg[1]) & 0xFF;
demayer 1:b36bbc1c6d27 405 data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers
demayer 1:b36bbc1c6d27 406 data[4] = (accel_bias_reg[2] >> 8) & 0xFF;
demayer 1:b36bbc1c6d27 407 data[5] = (accel_bias_reg[2]) & 0xFF;
demayer 1:b36bbc1c6d27 408 data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers
demayer 1:b36bbc1c6d27 409
demayer 1:b36bbc1c6d27 410 // Apparently this is not working for the acceleration biases in the MPU-9250
demayer 1:b36bbc1c6d27 411 // Are we handling the temperature correction bit properly?
demayer 1:b36bbc1c6d27 412 // Push accelerometer biases to hardware registers
demayer 1:b36bbc1c6d27 413 /* writeByte(MPU9250_ADDRESS, XA_OFFSET_H, data[0]);
demayer 1:b36bbc1c6d27 414 writeByte(MPU9250_ADDRESS, XA_OFFSET_L, data[1]);
demayer 1:b36bbc1c6d27 415 writeByte(MPU9250_ADDRESS, YA_OFFSET_H, data[2]);
demayer 1:b36bbc1c6d27 416 writeByte(MPU9250_ADDRESS, YA_OFFSET_L, data[3]);
demayer 1:b36bbc1c6d27 417 writeByte(MPU9250_ADDRESS, ZA_OFFSET_H, data[4]);
demayer 1:b36bbc1c6d27 418 writeByte(MPU9250_ADDRESS, ZA_OFFSET_L, data[5]);
demayer 1:b36bbc1c6d27 419 */
demayer 1:b36bbc1c6d27 420 // Output scaled accelerometer biases for manual subtraction in the main program
demayer 1:b36bbc1c6d27 421 dest2[0] = (float)accel_bias[0]/(float)accelsensitivity;
demayer 1:b36bbc1c6d27 422 dest2[1] = (float)accel_bias[1]/(float)accelsensitivity;
demayer 1:b36bbc1c6d27 423 dest2[2] = (float)accel_bias[2]/(float)accelsensitivity;
demayer 1:b36bbc1c6d27 424 }
demayer 1:b36bbc1c6d27 425
demayer 1:b36bbc1c6d27 426
demayer 1:b36bbc1c6d27 427 // Accelerometer and gyroscope self test; check calibration wrt factory settings
demayer 1:b36bbc1c6d27 428 void MPU9250::MPU9250SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass
demayer 1:b36bbc1c6d27 429 {
demayer 1:b36bbc1c6d27 430 uint8_t rawData[6] = {0, 0, 0, 0, 0, 0};
demayer 1:b36bbc1c6d27 431 uint8_t selfTest[6];
demayer 1:b36bbc1c6d27 432 int16_t gAvg[3], aAvg[3], aSTAvg[3], gSTAvg[3];
demayer 1:b36bbc1c6d27 433 float factoryTrim[6];
demayer 1:b36bbc1c6d27 434 uint8_t FS = 0;
demayer 1:b36bbc1c6d27 435
demayer 1:b36bbc1c6d27 436 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz
demayer 1:b36bbc1c6d27 437 writeByte(MPU9250_ADDRESS, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz
demayer 1:b36bbc1c6d27 438 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 1<<FS); // Set full scale range for the gyro to 250 dps
demayer 1:b36bbc1c6d27 439 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz
demayer 1:b36bbc1c6d27 440 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 1<<FS); // Set full scale range for the accelerometer to 2 g
demayer 1:b36bbc1c6d27 441
demayer 1:b36bbc1c6d27 442 for( int ii = 0; ii < 200; ii++) { // get average current values of gyro and acclerometer
demayer 1:b36bbc1c6d27 443
demayer 1:b36bbc1c6d27 444 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
demayer 1:b36bbc1c6d27 445 aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 446 aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 1:b36bbc1c6d27 447 aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 1:b36bbc1c6d27 448
demayer 1:b36bbc1c6d27 449 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
demayer 1:b36bbc1c6d27 450 gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 451 gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 1:b36bbc1c6d27 452 gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 1:b36bbc1c6d27 453 }
demayer 1:b36bbc1c6d27 454
demayer 1:b36bbc1c6d27 455 for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average current readings
demayer 1:b36bbc1c6d27 456 aAvg[ii] /= 200;
demayer 1:b36bbc1c6d27 457 gAvg[ii] /= 200;
demayer 1:b36bbc1c6d27 458 }
demayer 1:b36bbc1c6d27 459
demayer 1:b36bbc1c6d27 460 // Configure the accelerometer for self-test
demayer 1:b36bbc1c6d27 461 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g
demayer 1:b36bbc1c6d27 462 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
demayer 1:b36bbc1c6d27 463 wait(0.025); // Delay a while to let the device stabilize
demayer 1:b36bbc1c6d27 464
demayer 1:b36bbc1c6d27 465 for( int ii = 0; ii < 200; ii++) { // get average self-test values of gyro and acclerometer
demayer 1:b36bbc1c6d27 466
demayer 1:b36bbc1c6d27 467 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
demayer 1:b36bbc1c6d27 468 aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 469 aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 1:b36bbc1c6d27 470 aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 1:b36bbc1c6d27 471
demayer 1:b36bbc1c6d27 472 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
demayer 1:b36bbc1c6d27 473 gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 474 gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 1:b36bbc1c6d27 475 gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 1:b36bbc1c6d27 476 }
demayer 1:b36bbc1c6d27 477
demayer 1:b36bbc1c6d27 478 for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average self-test readings
demayer 1:b36bbc1c6d27 479 aSTAvg[ii] /= 200;
demayer 1:b36bbc1c6d27 480 gSTAvg[ii] /= 200;
demayer 1:b36bbc1c6d27 481 }
demayer 1:b36bbc1c6d27 482
demayer 1:b36bbc1c6d27 483 // Configure the gyro and accelerometer for normal operation
demayer 1:b36bbc1c6d27 484 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00);
demayer 1:b36bbc1c6d27 485 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00);
demayer 1:b36bbc1c6d27 486 wait(0.025); // Delay a while to let the device stabilize
demayer 1:b36bbc1c6d27 487
demayer 1:b36bbc1c6d27 488 // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg
demayer 1:b36bbc1c6d27 489 selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results
demayer 1:b36bbc1c6d27 490 selfTest[1] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_ACCEL); // Y-axis accel self-test results
demayer 1:b36bbc1c6d27 491 selfTest[2] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_ACCEL); // Z-axis accel self-test results
demayer 1:b36bbc1c6d27 492 selfTest[3] = readByte(MPU9250_ADDRESS, SELF_TEST_X_GYRO); // X-axis gyro self-test results
demayer 1:b36bbc1c6d27 493 selfTest[4] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_GYRO); // Y-axis gyro self-test results
demayer 1:b36bbc1c6d27 494 selfTest[5] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_GYRO); // Z-axis gyro self-test results
demayer 1:b36bbc1c6d27 495
demayer 1:b36bbc1c6d27 496 // Retrieve factory self-test value from self-test code reads
demayer 1:b36bbc1c6d27 497 factoryTrim[0] = (float)(2620/1<<FS)*(pow( 1.01, ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation
demayer 1:b36bbc1c6d27 498 factoryTrim[1] = (float)(2620/1<<FS)*(pow( 1.01, ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation
demayer 1:b36bbc1c6d27 499 factoryTrim[2] = (float)(2620/1<<FS)*(pow( 1.01, ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation
demayer 1:b36bbc1c6d27 500 factoryTrim[3] = (float)(2620/1<<FS)*(pow( 1.01, ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation
demayer 1:b36bbc1c6d27 501 factoryTrim[4] = (float)(2620/1<<FS)*(pow( 1.01, ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation
demayer 1:b36bbc1c6d27 502 factoryTrim[5] = (float)(2620/1<<FS)*(pow( 1.01, ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation
demayer 1:b36bbc1c6d27 503
demayer 1:b36bbc1c6d27 504 // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response
demayer 1:b36bbc1c6d27 505 // To get percent, must multiply by 100
demayer 1:b36bbc1c6d27 506 for (int i = 0; i < 3; i++) {
demayer 1:b36bbc1c6d27 507 destination[i] = 100.0*((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i]; // Report percent differences
demayer 1:b36bbc1c6d27 508 destination[i+3] = 100.0*((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3]; // Report percent differences
demayer 1:b36bbc1c6d27 509 }
demayer 1:b36bbc1c6d27 510
demayer 1:b36bbc1c6d27 511 }
demayer 1:b36bbc1c6d27 512
demayer 1:b36bbc1c6d27 513
demayer 1:b36bbc1c6d27 514
demayer 1:b36bbc1c6d27 515 // Implementation of Sebastian Madgwick's "...efficient orientation filter for... inertial/magnetic sensor arrays"
demayer 1:b36bbc1c6d27 516 // (see http://www.x-io.co.uk/category/open-source/ for examples and more details)
demayer 1:b36bbc1c6d27 517 // which fuses acceleration, rotation rate, and magnetic moments to produce a quaternion-based estimate of absolute
demayer 1:b36bbc1c6d27 518 // device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc.
demayer 1:b36bbc1c6d27 519 // The performance of the orientation filter is at least as good as conventional Kalman-based filtering algorithms
demayer 1:b36bbc1c6d27 520 // but is much less computationally intensive---it can be performed on a 3.3 V Pro Mini operating at 8 MHz!
demayer 1:b36bbc1c6d27 521 void MPU9250::MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
demayer 1:b36bbc1c6d27 522 {
demayer 1:b36bbc1c6d27 523 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
demayer 1:b36bbc1c6d27 524 float norm;
demayer 1:b36bbc1c6d27 525 float hx, hy, _2bx, _2bz;
demayer 1:b36bbc1c6d27 526 float s1, s2, s3, s4;
demayer 1:b36bbc1c6d27 527 float qDot1, qDot2, qDot3, qDot4;
demayer 1:b36bbc1c6d27 528
demayer 1:b36bbc1c6d27 529 // Auxiliary variables to avoid repeated arithmetic
demayer 1:b36bbc1c6d27 530 float _2q1mx;
demayer 1:b36bbc1c6d27 531 float _2q1my;
demayer 1:b36bbc1c6d27 532 float _2q1mz;
demayer 1:b36bbc1c6d27 533 float _2q2mx;
demayer 1:b36bbc1c6d27 534 float _4bx;
demayer 1:b36bbc1c6d27 535 float _4bz;
demayer 1:b36bbc1c6d27 536 float _2q1 = 2.0f * q1;
demayer 1:b36bbc1c6d27 537 float _2q2 = 2.0f * q2;
demayer 1:b36bbc1c6d27 538 float _2q3 = 2.0f * q3;
demayer 1:b36bbc1c6d27 539 float _2q4 = 2.0f * q4;
demayer 1:b36bbc1c6d27 540 float _2q1q3 = 2.0f * q1 * q3;
demayer 1:b36bbc1c6d27 541 float _2q3q4 = 2.0f * q3 * q4;
demayer 1:b36bbc1c6d27 542 float q1q1 = q1 * q1;
demayer 1:b36bbc1c6d27 543 float q1q2 = q1 * q2;
demayer 1:b36bbc1c6d27 544 float q1q3 = q1 * q3;
demayer 1:b36bbc1c6d27 545 float q1q4 = q1 * q4;
demayer 1:b36bbc1c6d27 546 float q2q2 = q2 * q2;
demayer 1:b36bbc1c6d27 547 float q2q3 = q2 * q3;
demayer 1:b36bbc1c6d27 548 float q2q4 = q2 * q4;
demayer 1:b36bbc1c6d27 549 float q3q3 = q3 * q3;
demayer 1:b36bbc1c6d27 550 float q3q4 = q3 * q4;
demayer 1:b36bbc1c6d27 551 float q4q4 = q4 * q4;
demayer 1:b36bbc1c6d27 552
demayer 1:b36bbc1c6d27 553 // Normalise accelerometer measurement
demayer 1:b36bbc1c6d27 554 norm = sqrt(ax * ax + ay * ay + az * az);
demayer 1:b36bbc1c6d27 555 if (norm == 0.0f) return; // handle NaN
demayer 1:b36bbc1c6d27 556 norm = 1.0f/norm;
demayer 1:b36bbc1c6d27 557 ax *= norm;
demayer 1:b36bbc1c6d27 558 ay *= norm;
demayer 1:b36bbc1c6d27 559 az *= norm;
demayer 1:b36bbc1c6d27 560
demayer 1:b36bbc1c6d27 561 // Normalise magnetometer measurement
demayer 1:b36bbc1c6d27 562 norm = sqrt(mx * mx + my * my + mz * mz);
demayer 1:b36bbc1c6d27 563 if (norm == 0.0f) return; // handle NaN
demayer 1:b36bbc1c6d27 564 norm = 1.0f/norm;
demayer 1:b36bbc1c6d27 565 mx *= norm;
demayer 1:b36bbc1c6d27 566 my *= norm;
demayer 1:b36bbc1c6d27 567 mz *= norm;
demayer 1:b36bbc1c6d27 568
demayer 1:b36bbc1c6d27 569 // Reference direction of Earth's magnetic field
demayer 1:b36bbc1c6d27 570 _2q1mx = 2.0f * q1 * mx;
demayer 1:b36bbc1c6d27 571 _2q1my = 2.0f * q1 * my;
demayer 1:b36bbc1c6d27 572 _2q1mz = 2.0f * q1 * mz;
demayer 1:b36bbc1c6d27 573 _2q2mx = 2.0f * q2 * mx;
demayer 1:b36bbc1c6d27 574 hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4;
demayer 1:b36bbc1c6d27 575 hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4;
demayer 1:b36bbc1c6d27 576 _2bx = sqrt(hx * hx + hy * hy);
demayer 1:b36bbc1c6d27 577 _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4;
demayer 1:b36bbc1c6d27 578 _4bx = 2.0f * _2bx;
demayer 1:b36bbc1c6d27 579 _4bz = 2.0f * _2bz;
demayer 1:b36bbc1c6d27 580
demayer 1:b36bbc1c6d27 581 // Gradient decent algorithm corrective step
demayer 1:b36bbc1c6d27 582 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);
demayer 1:b36bbc1c6d27 583 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);
demayer 1:b36bbc1c6d27 584 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);
demayer 1:b36bbc1c6d27 585 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);
demayer 1:b36bbc1c6d27 586 norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4); // normalise step magnitude
demayer 1:b36bbc1c6d27 587 norm = 1.0f/norm;
demayer 1:b36bbc1c6d27 588 s1 *= norm;
demayer 1:b36bbc1c6d27 589 s2 *= norm;
demayer 1:b36bbc1c6d27 590 s3 *= norm;
demayer 1:b36bbc1c6d27 591 s4 *= norm;
demayer 1:b36bbc1c6d27 592
demayer 1:b36bbc1c6d27 593 // Compute rate of change of quaternion
demayer 1:b36bbc1c6d27 594 qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1;
demayer 1:b36bbc1c6d27 595 qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2;
demayer 1:b36bbc1c6d27 596 qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3;
demayer 1:b36bbc1c6d27 597 qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4;
demayer 1:b36bbc1c6d27 598
demayer 1:b36bbc1c6d27 599 // Integrate to yield quaternion
demayer 1:b36bbc1c6d27 600 q1 += qDot1 * deltat;
demayer 1:b36bbc1c6d27 601 q2 += qDot2 * deltat;
demayer 1:b36bbc1c6d27 602 q3 += qDot3 * deltat;
demayer 1:b36bbc1c6d27 603 q4 += qDot4 * deltat;
demayer 1:b36bbc1c6d27 604 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion
demayer 1:b36bbc1c6d27 605 norm = 1.0f/norm;
demayer 1:b36bbc1c6d27 606 q[0] = q1 * norm;
demayer 1:b36bbc1c6d27 607 q[1] = q2 * norm;
demayer 1:b36bbc1c6d27 608 q[2] = q3 * norm;
demayer 1:b36bbc1c6d27 609 q[3] = q4 * norm;
demayer 1:b36bbc1c6d27 610
demayer 1:b36bbc1c6d27 611 }
demayer 1:b36bbc1c6d27 612
demayer 1:b36bbc1c6d27 613
demayer 1:b36bbc1c6d27 614
demayer 1:b36bbc1c6d27 615 // Similar to Madgwick scheme but uses proportional and integral filtering on the error between estimated reference vectors and
demayer 1:b36bbc1c6d27 616 // measured ones.
demayer 1:b36bbc1c6d27 617 void MPU9250::MahonyQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
demayer 1:b36bbc1c6d27 618 {
demayer 1:b36bbc1c6d27 619 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
demayer 1:b36bbc1c6d27 620 float norm;
demayer 1:b36bbc1c6d27 621 float hx, hy, bx, bz;
demayer 1:b36bbc1c6d27 622 float vx, vy, vz, wx, wy, wz;
demayer 1:b36bbc1c6d27 623 float ex, ey, ez;
demayer 1:b36bbc1c6d27 624 float pa, pb, pc;
demayer 1:b36bbc1c6d27 625
demayer 1:b36bbc1c6d27 626 // Auxiliary variables to avoid repeated arithmetic
demayer 1:b36bbc1c6d27 627 float q1q1 = q1 * q1;
demayer 1:b36bbc1c6d27 628 float q1q2 = q1 * q2;
demayer 1:b36bbc1c6d27 629 float q1q3 = q1 * q3;
demayer 1:b36bbc1c6d27 630 float q1q4 = q1 * q4;
demayer 1:b36bbc1c6d27 631 float q2q2 = q2 * q2;
demayer 1:b36bbc1c6d27 632 float q2q3 = q2 * q3;
demayer 1:b36bbc1c6d27 633 float q2q4 = q2 * q4;
demayer 1:b36bbc1c6d27 634 float q3q3 = q3 * q3;
demayer 1:b36bbc1c6d27 635 float q3q4 = q3 * q4;
demayer 1:b36bbc1c6d27 636 float q4q4 = q4 * q4;
demayer 1:b36bbc1c6d27 637
demayer 1:b36bbc1c6d27 638 // Normalise accelerometer measurement
demayer 1:b36bbc1c6d27 639 norm = sqrt(ax * ax + ay * ay + az * az);
demayer 1:b36bbc1c6d27 640 if (norm == 0.0f) return; // handle NaN
demayer 1:b36bbc1c6d27 641 norm = 1.0f / norm; // use reciprocal for division
demayer 1:b36bbc1c6d27 642 ax *= norm;
demayer 1:b36bbc1c6d27 643 ay *= norm;
demayer 1:b36bbc1c6d27 644 az *= norm;
demayer 1:b36bbc1c6d27 645
demayer 1:b36bbc1c6d27 646 // Normalise magnetometer measurement
demayer 1:b36bbc1c6d27 647 norm = sqrt(mx * mx + my * my + mz * mz);
demayer 1:b36bbc1c6d27 648 if (norm == 0.0f) return; // handle NaN
demayer 1:b36bbc1c6d27 649 norm = 1.0f / norm; // use reciprocal for division
demayer 1:b36bbc1c6d27 650 mx *= norm;
demayer 1:b36bbc1c6d27 651 my *= norm;
demayer 1:b36bbc1c6d27 652 mz *= norm;
demayer 1:b36bbc1c6d27 653
demayer 1:b36bbc1c6d27 654 // Reference direction of Earth's magnetic field
demayer 1:b36bbc1c6d27 655 hx = 2.0f * mx * (0.5f - q3q3 - q4q4) + 2.0f * my * (q2q3 - q1q4) + 2.0f * mz * (q2q4 + q1q3);
demayer 1:b36bbc1c6d27 656 hy = 2.0f * mx * (q2q3 + q1q4) + 2.0f * my * (0.5f - q2q2 - q4q4) + 2.0f * mz * (q3q4 - q1q2);
demayer 1:b36bbc1c6d27 657 bx = sqrt((hx * hx) + (hy * hy));
demayer 1:b36bbc1c6d27 658 bz = 2.0f * mx * (q2q4 - q1q3) + 2.0f * my * (q3q4 + q1q2) + 2.0f * mz * (0.5f - q2q2 - q3q3);
demayer 1:b36bbc1c6d27 659
demayer 1:b36bbc1c6d27 660 // Estimated direction of gravity and magnetic field
demayer 1:b36bbc1c6d27 661 vx = 2.0f * (q2q4 - q1q3);
demayer 1:b36bbc1c6d27 662 vy = 2.0f * (q1q2 + q3q4);
demayer 1:b36bbc1c6d27 663 vz = q1q1 - q2q2 - q3q3 + q4q4;
demayer 1:b36bbc1c6d27 664 wx = 2.0f * bx * (0.5f - q3q3 - q4q4) + 2.0f * bz * (q2q4 - q1q3);
demayer 1:b36bbc1c6d27 665 wy = 2.0f * bx * (q2q3 - q1q4) + 2.0f * bz * (q1q2 + q3q4);
demayer 1:b36bbc1c6d27 666 wz = 2.0f * bx * (q1q3 + q2q4) + 2.0f * bz * (0.5f - q2q2 - q3q3);
demayer 1:b36bbc1c6d27 667
demayer 1:b36bbc1c6d27 668 // Error is cross product between estimated direction and measured direction of gravity
demayer 1:b36bbc1c6d27 669 ex = (ay * vz - az * vy) + (my * wz - mz * wy);
demayer 1:b36bbc1c6d27 670 ey = (az * vx - ax * vz) + (mz * wx - mx * wz);
demayer 1:b36bbc1c6d27 671 ez = (ax * vy - ay * vx) + (mx * wy - my * wx);
demayer 1:b36bbc1c6d27 672 if (Ki > 0.0f) {
demayer 1:b36bbc1c6d27 673 eInt[0] += ex; // accumulate integral error
demayer 1:b36bbc1c6d27 674 eInt[1] += ey;
demayer 1:b36bbc1c6d27 675 eInt[2] += ez;
demayer 1:b36bbc1c6d27 676 } else {
demayer 1:b36bbc1c6d27 677 eInt[0] = 0.0f; // prevent integral wind up
demayer 1:b36bbc1c6d27 678 eInt[1] = 0.0f;
demayer 1:b36bbc1c6d27 679 eInt[2] = 0.0f;
demayer 1:b36bbc1c6d27 680 }
demayer 1:b36bbc1c6d27 681
demayer 1:b36bbc1c6d27 682 // Apply feedback terms
demayer 1:b36bbc1c6d27 683 gx = gx + Kp * ex + Ki * eInt[0];
demayer 1:b36bbc1c6d27 684 gy = gy + Kp * ey + Ki * eInt[1];
demayer 1:b36bbc1c6d27 685 gz = gz + Kp * ez + Ki * eInt[2];
demayer 1:b36bbc1c6d27 686
demayer 1:b36bbc1c6d27 687 // Integrate rate of change of quaternion
demayer 1:b36bbc1c6d27 688 pa = q2;
demayer 1:b36bbc1c6d27 689 pb = q3;
demayer 1:b36bbc1c6d27 690 pc = q4;
demayer 1:b36bbc1c6d27 691 q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * deltat);
demayer 1:b36bbc1c6d27 692 q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * deltat);
demayer 1:b36bbc1c6d27 693 q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * deltat);
demayer 1:b36bbc1c6d27 694 q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * deltat);
demayer 1:b36bbc1c6d27 695
demayer 1:b36bbc1c6d27 696 // Normalise quaternion
demayer 1:b36bbc1c6d27 697 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);
demayer 1:b36bbc1c6d27 698 norm = 1.0f / norm;
demayer 1:b36bbc1c6d27 699 q[0] = q1 * norm;
demayer 1:b36bbc1c6d27 700 q[1] = q2 * norm;
demayer 1:b36bbc1c6d27 701 q[2] = q3 * norm;
demayer 1:b36bbc1c6d27 702 q[3] = q4 * norm;
demayer 1:b36bbc1c6d27 703
demayer 1:b36bbc1c6d27 704 }
demayer 1:b36bbc1c6d27 705
demayer 1:b36bbc1c6d27 706 // Integrates the acceleration to get the boards translative velocity
demayer 1:b36bbc1c6d27 707 void MPU9250::velocityUpdate(float ax, float ay, float az)
demayer 1:b36bbc1c6d27 708 {
demayer 1:b36bbc1c6d27 709 // short name local variable for readability
demayer 1:b36bbc1c6d27 710
demayer 1:b36bbc1c6d27 711 v_trans[0] = deltat*0.5*(a_old[0] + ax*GRAVITATION) + v_trans[0];
demayer 1:b36bbc1c6d27 712 v_trans[1] = deltat*0.5*(a_old[1] + ay*GRAVITATION) + v_trans[1];
demayer 1:b36bbc1c6d27 713 v_trans[2] = deltat*0.5*(a_old[2] + az*GRAVITATION + GRAVITATION) + v_trans[2];
demayer 1:b36bbc1c6d27 714
demayer 1:b36bbc1c6d27 715 a_old[0] = ax*GRAVITATION;
demayer 1:b36bbc1c6d27 716 a_old[1] = ay*GRAVITATION;
demayer 1:b36bbc1c6d27 717 a_old[2] = az*GRAVITATION;
demayer 1:b36bbc1c6d27 718 }
demayer 1:b36bbc1c6d27 719
demayer 1:b36bbc1c6d27 720 void MPU9250::readIMU()
demayer 1:b36bbc1c6d27 721 {
demayer 1:b36bbc1c6d27 722 // If intPin goes high, all data registers have new data
demayer 1:b36bbc1c6d27 723 if(mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) { // On interrupt, check if data ready interrupt
demayer 1:b36bbc1c6d27 724
demayer 1:b36bbc1c6d27 725 mpu9250.readAccelData(accelCount); // Read the x/y/z adc values
demayer 1:b36bbc1c6d27 726 // Now we'll calculate the accleration value into actual g's
demayer 1:b36bbc1c6d27 727 ax = (float)accelCount[0]*aRes - accelBias[0]; // get actual g value, this depends on scale being set
demayer 1:b36bbc1c6d27 728 ay = (float)accelCount[1]*aRes - accelBias[1];
demayer 1:b36bbc1c6d27 729 az = (float)accelCount[2]*aRes - accelBias[2];
demayer 1:b36bbc1c6d27 730
demayer 1:b36bbc1c6d27 731 mpu9250.readGyroData(gyroCount); // Read the x/y/z adc values
demayer 1:b36bbc1c6d27 732 // Calculate the gyro value into actual degrees per second
demayer 1:b36bbc1c6d27 733 gx = (float)gyroCount[0]*gRes - gyroBias[0]; // get actual gyro value, this depends on scale being set
demayer 1:b36bbc1c6d27 734 gy = (float)gyroCount[1]*gRes - gyroBias[1];
demayer 1:b36bbc1c6d27 735 gz = (float)gyroCount[2]*gRes - gyroBias[2];
demayer 1:b36bbc1c6d27 736
demayer 1:b36bbc1c6d27 737 mpu9250.readMagData(magCount); // Read the x/y/z adc values
demayer 1:b36bbc1c6d27 738 // Calculate the magnetometer values in milliGauss
demayer 1:b36bbc1c6d27 739 // Include factory calibration per data sheet and user environmental corrections
demayer 1:b36bbc1c6d27 740 mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0]; // get actual magnetometer value, this depends on scale being set
demayer 1:b36bbc1c6d27 741 my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1];
demayer 1:b36bbc1c6d27 742 mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2];
demayer 1:b36bbc1c6d27 743 }
demayer 1:b36bbc1c6d27 744
demayer 1:b36bbc1c6d27 745 pc.printf("ax, ay, az, delta_t;%f;%f;%f;%f\n\r", ax, ay, az*GRAVITATION + GRAVITATION, deltat);
demayer 1:b36bbc1c6d27 746
demayer 1:b36bbc1c6d27 747 Now = t.read_us();
demayer 1:b36bbc1c6d27 748
demayer 1:b36bbc1c6d27 749 deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update
demayer 1:b36bbc1c6d27 750 lastUpdate = Now;
demayer 1:b36bbc1c6d27 751
demayer 1:b36bbc1c6d27 752 sum += deltat;
demayer 1:b36bbc1c6d27 753 sumCount++;
demayer 1:b36bbc1c6d27 754
demayer 1:b36bbc1c6d27 755
demayer 1:b36bbc1c6d27 756 mpu9250.velocityUpdate(ax, ay, az);
demayer 1:b36bbc1c6d27 757
demayer 1:b36bbc1c6d27 758 // Pass gyro rate as rad/s
demayer 1:b36bbc1c6d27 759 mpu9250.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);
demayer 1:b36bbc1c6d27 760 //mpu9250.MahonyQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);
demayer 1:b36bbc1c6d27 761
demayer 1:b36bbc1c6d27 762 // Serial print and/or display at 0.5 s rate independent of data rates
demayer 1:b36bbc1c6d27 763 delt_t = t.read_ms() - _count;
demayer 1:b36bbc1c6d27 764
demayer 1:b36bbc1c6d27 765 //-----------------------------------------
demayer 1:b36bbc1c6d27 766 // Update displayed value
demayer 1:b36bbc1c6d27 767 if (delt_t > SAMPLE_TIME) {
demayer 1:b36bbc1c6d27 768
demayer 1:b36bbc1c6d27 769
demayer 1:b36bbc1c6d27 770
demayer 1:b36bbc1c6d27 771 //pc.printf("vx, vy, vz: %f %f %f\n\r", v_trans[0], v_trans[1], v_trans[2]);
demayer 1:b36bbc1c6d27 772
demayer 1:b36bbc1c6d27 773
demayer 1:b36bbc1c6d27 774 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]);
demayer 1:b36bbc1c6d27 775 pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2]));
demayer 1:b36bbc1c6d27 776 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]);
demayer 1:b36bbc1c6d27 777 pitch *= 180.0f / PI;
demayer 1:b36bbc1c6d27 778 yaw *= 180.0f / PI;
demayer 1:b36bbc1c6d27 779 yaw -= 2.93f; // Declination at 8572 Berg TG: +2° 56'
demayer 1:b36bbc1c6d27 780 roll *= 180.0f / PI;
demayer 1:b36bbc1c6d27 781
demayer 1:b36bbc1c6d27 782 myData.ax = yaw;
demayer 1:b36bbc1c6d27 783 myData.ay = pitch;
demayer 1:b36bbc1c6d27 784 myData.az = roll;
demayer 1:b36bbc1c6d27 785
demayer 1:b36bbc1c6d27 786
demayer 1:b36bbc1c6d27 787 myled= !myled;
demayer 1:b36bbc1c6d27 788 _count = t.read_ms();
demayer 1:b36bbc1c6d27 789
demayer 1:b36bbc1c6d27 790 if(_count > 1<<21) {
demayer 1:b36bbc1c6d27 791 t.start(); // start the timer over again if ~30 minutes has passed
demayer 1:b36bbc1c6d27 792 _count = 0;
demayer 1:b36bbc1c6d27 793 deltat= 0;
demayer 1:b36bbc1c6d27 794 lastUpdate = t.read_us();
demayer 1:b36bbc1c6d27 795 }
demayer 1:b36bbc1c6d27 796 sum = 0;
demayer 1:b36bbc1c6d27 797 sumCount = 0;
demayer 1:b36bbc1c6d27 798 }
demayer 1:b36bbc1c6d27 799 }
demayer 1:b36bbc1c6d27 800
demayer 1:b36bbc1c6d27 801
demayer 1:b36bbc1c6d27 802 void MPU9250::imuSetup()
demayer 1:b36bbc1c6d27 803 {
demayer 1:b36bbc1c6d27 804 //Set up I2C
demayer 1:b36bbc1c6d27 805 i2c.frequency(400000); // use fast (400 kHz) I2C
demayer 1:b36bbc1c6d27 806
demayer 1:b36bbc1c6d27 807 pc.printf("CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock);
demayer 1:b36bbc1c6d27 808
demayer 1:b36bbc1c6d27 809 t.start();
demayer 1:b36bbc1c6d27 810 // lcd.setBrightness(0.05);
demayer 1:b36bbc1c6d27 811
demayer 1:b36bbc1c6d27 812
demayer 1:b36bbc1c6d27 813 // Read the WHO_AM_I register, this is a good test of communication
demayer 1:b36bbc1c6d27 814 uint8_t whoami = mpu9250.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250); // Read WHO_AM_I register for MPU-9250
demayer 1:b36bbc1c6d27 815 pc.printf("I AM 0x%x\n\r", whoami);
demayer 1:b36bbc1c6d27 816 pc.printf("I SHOULD BE 0x71\n\r");
demayer 1:b36bbc1c6d27 817
demayer 1:b36bbc1c6d27 818 if (whoami == 0x71) { // WHO_AM_I should always be 0x68
demayer 1:b36bbc1c6d27 819 pc.printf("MPU9250 WHO_AM_I is 0x%x\n\r", whoami);
demayer 1:b36bbc1c6d27 820 pc.printf("MPU9250 is online...\n\r");
demayer 1:b36bbc1c6d27 821 sprintf(buffer, "0x%x", whoami);
demayer 1:b36bbc1c6d27 822 wait(1);
demayer 1:b36bbc1c6d27 823
demayer 1:b36bbc1c6d27 824 mpu9250.resetMPU9250(); // Reset registers to default in preparation for device calibration
demayer 1:b36bbc1c6d27 825 mpu9250.MPU9250SelfTest(SelfTest); // Start by performing self test and reporting values
demayer 1:b36bbc1c6d27 826 pc.printf("x-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[0]);
demayer 1:b36bbc1c6d27 827 pc.printf("y-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[1]);
demayer 1:b36bbc1c6d27 828 pc.printf("z-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[2]);
demayer 1:b36bbc1c6d27 829 pc.printf("x-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[3]);
demayer 1:b36bbc1c6d27 830 pc.printf("y-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[4]);
demayer 1:b36bbc1c6d27 831 pc.printf("z-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[5]);
demayer 1:b36bbc1c6d27 832 mpu9250.calibrateMPU9250(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers
demayer 1:b36bbc1c6d27 833 pc.printf("x gyro bias = %f\n\r", gyroBias[0]);
demayer 1:b36bbc1c6d27 834 pc.printf("y gyro bias = %f\n\r", gyroBias[1]);
demayer 1:b36bbc1c6d27 835 pc.printf("z gyro bias = %f\n\r", gyroBias[2]);
demayer 1:b36bbc1c6d27 836 pc.printf("x accel bias = %f\n\r", accelBias[0]);
demayer 1:b36bbc1c6d27 837 pc.printf("y accel bias = %f\n\r", accelBias[1]);
demayer 1:b36bbc1c6d27 838 pc.printf("z accel bias = %f\n\r", accelBias[2]);
demayer 1:b36bbc1c6d27 839 wait(2);
demayer 1:b36bbc1c6d27 840 mpu9250.initMPU9250();
demayer 1:b36bbc1c6d27 841 pc.printf("MPU9250 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
demayer 1:b36bbc1c6d27 842 mpu9250.initAK8963(magCalibration);
demayer 1:b36bbc1c6d27 843 pc.printf("AK8963 initialized for active data mode....\n\r"); // Initialize device for active mode read of magnetometer
demayer 1:b36bbc1c6d27 844 pc.printf("Accelerometer full-scale range = %f g\n\r", 2.0f*(float)(1<<Ascale));
demayer 1:b36bbc1c6d27 845 pc.printf("Gyroscope full-scale range = %f deg/s\n\r", 250.0f*(float)(1<<Gscale));
demayer 1:b36bbc1c6d27 846 if(Mscale == 0) pc.printf("Magnetometer resolution = 14 bits\n\r");
demayer 1:b36bbc1c6d27 847 if(Mscale == 1) pc.printf("Magnetometer resolution = 16 bits\n\r");
demayer 1:b36bbc1c6d27 848 if(Mmode == 2) pc.printf("Magnetometer ODR = 8 Hz\n\r");
demayer 1:b36bbc1c6d27 849 if(Mmode == 6) pc.printf("Magnetometer ODR = 100 Hz\n\r");
demayer 1:b36bbc1c6d27 850 wait(1);
demayer 1:b36bbc1c6d27 851 } else {
demayer 1:b36bbc1c6d27 852 pc.printf("Could not connect to MPU9250: \n\r");
demayer 1:b36bbc1c6d27 853 pc.printf("%#x \n", whoami);
demayer 1:b36bbc1c6d27 854 sprintf(buffer, "WHO_AM_I 0x%x", whoami);
demayer 1:b36bbc1c6d27 855
demayer 1:b36bbc1c6d27 856 while(1) {
demayer 1:b36bbc1c6d27 857 // Loop forever if communication doesn't happen
demayer 1:b36bbc1c6d27 858 pc.printf("no IMU detected (verify if it's plugged in)\n\r");
demayer 1:b36bbc1c6d27 859 }
demayer 1:b36bbc1c6d27 860 }
demayer 1:b36bbc1c6d27 861
demayer 1:b36bbc1c6d27 862 mpu9250.getAres(); // Get accelerometer sensitivity
demayer 1:b36bbc1c6d27 863 mpu9250.getGres(); // Get gyro sensitivity
demayer 1:b36bbc1c6d27 864 mpu9250.getMres(); // Get magnetometer sensitivity
demayer 1:b36bbc1c6d27 865 pc.printf("Accelerometer sensitivity is %f LSB/g \n\r", 1.0f/aRes);
demayer 1:b36bbc1c6d27 866 pc.printf("Gyroscope sensitivity is %f LSB/deg/s \n\r", 1.0f/gRes);
demayer 1:b36bbc1c6d27 867 pc.printf("Magnetometer sensitivity is %f LSB/G \n\r", 1.0f/mRes);
demayer 1:b36bbc1c6d27 868 magbias[0] = +470.; // User environmental x-axis correction in milliGauss, should be automatically calculated
demayer 1:b36bbc1c6d27 869 magbias[1] = +120.; // User environmental x-axis correction in milliGauss
demayer 1:b36bbc1c6d27 870 magbias[2] = +125.; // User environmental x-axis correction in milliGauss
demayer 1:b36bbc1c6d27 871 }
demayer 1:b36bbc1c6d27 872
demayer 1:b36bbc1c6d27 873 accData_t MPU9250::getVelocityFromIMU(){
demayer 1:b36bbc1c6d27 874 readIMU();
demayer 1:b36bbc1c6d27 875
demayer 1:b36bbc1c6d27 876 return myData;
demayer 1:b36bbc1c6d27 877 }