Marco Mayer / Mbed OS Queue

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MPU9250.h@0:6bf0743ece18, 2020-03-28 (annotated)

Committer:
demayer
Date:
Sat Mar 28 15:28:19 2020 +0000
Revision:
0:6bf0743ece18
Child:
1:b36bbc1c6d27
IMU Thread with an event-queue running parallel to handle tasks like a 5 times blinking LED. Button with interrupt detected.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
demayer 0:6bf0743ece18 1 #ifndef MPU9250_H
demayer 0:6bf0743ece18 2 #define MPU9250_H
demayer 0:6bf0743ece18 3
demayer 0:6bf0743ece18 4 #include "mbed.h"
demayer 0:6bf0743ece18 5 #include "math.h"
demayer 0:6bf0743ece18 6
demayer 0:6bf0743ece18 7 // See also MPU-9250 Register Map and Descriptions, Revision 4.0, RM-MPU-9250A-00, Rev. 1.4, 9/9/2013 for registers not listed in
demayer 0:6bf0743ece18 8 // above document; the MPU9250 and MPU9150 are virtually identical but the latter has a different register map
demayer 0:6bf0743ece18 9 //
demayer 0:6bf0743ece18 10 //Magnetometer Registers
demayer 0:6bf0743ece18 11 #define AK8963_ADDRESS 0x0C<<1
demayer 0:6bf0743ece18 12 #define WHO_AM_I_AK8963 0x00 // should return 0x48
demayer 0:6bf0743ece18 13 #define INFO 0x01
demayer 0:6bf0743ece18 14 #define AK8963_ST1 0x02 // data ready status bit 0
demayer 0:6bf0743ece18 15 #define AK8963_XOUT_L 0x03 // data
demayer 0:6bf0743ece18 16 #define AK8963_XOUT_H 0x04
demayer 0:6bf0743ece18 17 #define AK8963_YOUT_L 0x05
demayer 0:6bf0743ece18 18 #define AK8963_YOUT_H 0x06
demayer 0:6bf0743ece18 19 #define AK8963_ZOUT_L 0x07
demayer 0:6bf0743ece18 20 #define AK8963_ZOUT_H 0x08
demayer 0:6bf0743ece18 21 #define AK8963_ST2 0x09 // Data overflow bit 3 and data read error status bit 2
demayer 0:6bf0743ece18 22 #define AK8963_CNTL 0x0A // Power down (0000), single-measurement (0001), self-test (1000) and Fuse ROM (1111) modes on bits 3:0
demayer 0:6bf0743ece18 23 #define AK8963_ASTC 0x0C // Self test control
demayer 0:6bf0743ece18 24 #define AK8963_I2CDIS 0x0F // I2C disable
demayer 0:6bf0743ece18 25 #define AK8963_ASAX 0x10 // Fuse ROM x-axis sensitivity adjustment value
demayer 0:6bf0743ece18 26 #define AK8963_ASAY 0x11 // Fuse ROM y-axis sensitivity adjustment value
demayer 0:6bf0743ece18 27 #define AK8963_ASAZ 0x12 // Fuse ROM z-axis sensitivity adjustment value
demayer 0:6bf0743ece18 28
demayer 0:6bf0743ece18 29 #define SELF_TEST_X_GYRO 0x00
demayer 0:6bf0743ece18 30 #define SELF_TEST_Y_GYRO 0x01
demayer 0:6bf0743ece18 31 #define SELF_TEST_Z_GYRO 0x02
demayer 0:6bf0743ece18 32
demayer 0:6bf0743ece18 33 /*#define X_FINE_GAIN 0x03 // [7:0] fine gain
demayer 0:6bf0743ece18 34 #define Y_FINE_GAIN 0x04
demayer 0:6bf0743ece18 35 #define Z_FINE_GAIN 0x05
demayer 0:6bf0743ece18 36 #define XA_OFFSET_H 0x06 // User-defined trim values for accelerometer
demayer 0:6bf0743ece18 37 #define XA_OFFSET_L_TC 0x07
demayer 0:6bf0743ece18 38 #define YA_OFFSET_H 0x08
demayer 0:6bf0743ece18 39 #define YA_OFFSET_L_TC 0x09
demayer 0:6bf0743ece18 40 #define ZA_OFFSET_H 0x0A
demayer 0:6bf0743ece18 41 #define ZA_OFFSET_L_TC 0x0B */
demayer 0:6bf0743ece18 42
demayer 0:6bf0743ece18 43 #define SELF_TEST_X_ACCEL 0x0D
demayer 0:6bf0743ece18 44 #define SELF_TEST_Y_ACCEL 0x0E
demayer 0:6bf0743ece18 45 #define SELF_TEST_Z_ACCEL 0x0F
demayer 0:6bf0743ece18 46
demayer 0:6bf0743ece18 47 #define SELF_TEST_A 0x10
demayer 0:6bf0743ece18 48
demayer 0:6bf0743ece18 49 #define XG_OFFSET_H 0x13 // User-defined trim values for gyroscope
demayer 0:6bf0743ece18 50 #define XG_OFFSET_L 0x14
demayer 0:6bf0743ece18 51 #define YG_OFFSET_H 0x15
demayer 0:6bf0743ece18 52 #define YG_OFFSET_L 0x16
demayer 0:6bf0743ece18 53 #define ZG_OFFSET_H 0x17
demayer 0:6bf0743ece18 54 #define ZG_OFFSET_L 0x18
demayer 0:6bf0743ece18 55 #define SMPLRT_DIV 0x19
demayer 0:6bf0743ece18 56 #define CONFIG 0x1A
demayer 0:6bf0743ece18 57 #define GYRO_CONFIG 0x1B
demayer 0:6bf0743ece18 58 #define ACCEL_CONFIG 0x1C
demayer 0:6bf0743ece18 59 #define ACCEL_CONFIG2 0x1D
demayer 0:6bf0743ece18 60 #define LP_ACCEL_ODR 0x1E
demayer 0:6bf0743ece18 61 #define WOM_THR 0x1F
demayer 0:6bf0743ece18 62
demayer 0:6bf0743ece18 63 #define MOT_DUR 0x20 // Duration counter threshold for motion interrupt generation, 1 kHz rate, LSB = 1 ms
demayer 0:6bf0743ece18 64 #define ZMOT_THR 0x21 // Zero-motion detection threshold bits [7:0]
demayer 0:6bf0743ece18 65 #define ZRMOT_DUR 0x22 // Duration counter threshold for zero motion interrupt generation, 16 Hz rate, LSB = 64 ms
demayer 0:6bf0743ece18 66
demayer 0:6bf0743ece18 67 #define FIFO_EN 0x23
demayer 0:6bf0743ece18 68 #define I2C_MST_CTRL 0x24
demayer 0:6bf0743ece18 69 #define I2C_SLV0_ADDR 0x25
demayer 0:6bf0743ece18 70 #define I2C_SLV0_REG 0x26
demayer 0:6bf0743ece18 71 #define I2C_SLV0_CTRL 0x27
demayer 0:6bf0743ece18 72 #define I2C_SLV1_ADDR 0x28
demayer 0:6bf0743ece18 73 #define I2C_SLV1_REG 0x29
demayer 0:6bf0743ece18 74 #define I2C_SLV1_CTRL 0x2A
demayer 0:6bf0743ece18 75 #define I2C_SLV2_ADDR 0x2B
demayer 0:6bf0743ece18 76 #define I2C_SLV2_REG 0x2C
demayer 0:6bf0743ece18 77 #define I2C_SLV2_CTRL 0x2D
demayer 0:6bf0743ece18 78 #define I2C_SLV3_ADDR 0x2E
demayer 0:6bf0743ece18 79 #define I2C_SLV3_REG 0x2F
demayer 0:6bf0743ece18 80 #define I2C_SLV3_CTRL 0x30
demayer 0:6bf0743ece18 81 #define I2C_SLV4_ADDR 0x31
demayer 0:6bf0743ece18 82 #define I2C_SLV4_REG 0x32
demayer 0:6bf0743ece18 83 #define I2C_SLV4_DO 0x33
demayer 0:6bf0743ece18 84 #define I2C_SLV4_CTRL 0x34
demayer 0:6bf0743ece18 85 #define I2C_SLV4_DI 0x35
demayer 0:6bf0743ece18 86 #define I2C_MST_STATUS 0x36
demayer 0:6bf0743ece18 87 #define INT_PIN_CFG 0x37
demayer 0:6bf0743ece18 88 #define INT_ENABLE 0x38
demayer 0:6bf0743ece18 89 #define DMP_INT_STATUS 0x39 // Check DMP interrupt
demayer 0:6bf0743ece18 90 #define INT_STATUS 0x3A
demayer 0:6bf0743ece18 91 #define ACCEL_XOUT_H 0x3B
demayer 0:6bf0743ece18 92 #define ACCEL_XOUT_L 0x3C
demayer 0:6bf0743ece18 93 #define ACCEL_YOUT_H 0x3D
demayer 0:6bf0743ece18 94 #define ACCEL_YOUT_L 0x3E
demayer 0:6bf0743ece18 95 #define ACCEL_ZOUT_H 0x3F
demayer 0:6bf0743ece18 96 #define ACCEL_ZOUT_L 0x40
demayer 0:6bf0743ece18 97 #define TEMP_OUT_H 0x41
demayer 0:6bf0743ece18 98 #define TEMP_OUT_L 0x42
demayer 0:6bf0743ece18 99 #define GYRO_XOUT_H 0x43
demayer 0:6bf0743ece18 100 #define GYRO_XOUT_L 0x44
demayer 0:6bf0743ece18 101 #define GYRO_YOUT_H 0x45
demayer 0:6bf0743ece18 102 #define GYRO_YOUT_L 0x46
demayer 0:6bf0743ece18 103 #define GYRO_ZOUT_H 0x47
demayer 0:6bf0743ece18 104 #define GYRO_ZOUT_L 0x48
demayer 0:6bf0743ece18 105 #define EXT_SENS_DATA_00 0x49
demayer 0:6bf0743ece18 106 #define EXT_SENS_DATA_01 0x4A
demayer 0:6bf0743ece18 107 #define EXT_SENS_DATA_02 0x4B
demayer 0:6bf0743ece18 108 #define EXT_SENS_DATA_03 0x4C
demayer 0:6bf0743ece18 109 #define EXT_SENS_DATA_04 0x4D
demayer 0:6bf0743ece18 110 #define EXT_SENS_DATA_05 0x4E
demayer 0:6bf0743ece18 111 #define EXT_SENS_DATA_06 0x4F
demayer 0:6bf0743ece18 112 #define EXT_SENS_DATA_07 0x50
demayer 0:6bf0743ece18 113 #define EXT_SENS_DATA_08 0x51
demayer 0:6bf0743ece18 114 #define EXT_SENS_DATA_09 0x52
demayer 0:6bf0743ece18 115 #define EXT_SENS_DATA_10 0x53
demayer 0:6bf0743ece18 116 #define EXT_SENS_DATA_11 0x54
demayer 0:6bf0743ece18 117 #define EXT_SENS_DATA_12 0x55
demayer 0:6bf0743ece18 118 #define EXT_SENS_DATA_13 0x56
demayer 0:6bf0743ece18 119 #define EXT_SENS_DATA_14 0x57
demayer 0:6bf0743ece18 120 #define EXT_SENS_DATA_15 0x58
demayer 0:6bf0743ece18 121 #define EXT_SENS_DATA_16 0x59
demayer 0:6bf0743ece18 122 #define EXT_SENS_DATA_17 0x5A
demayer 0:6bf0743ece18 123 #define EXT_SENS_DATA_18 0x5B
demayer 0:6bf0743ece18 124 #define EXT_SENS_DATA_19 0x5C
demayer 0:6bf0743ece18 125 #define EXT_SENS_DATA_20 0x5D
demayer 0:6bf0743ece18 126 #define EXT_SENS_DATA_21 0x5E
demayer 0:6bf0743ece18 127 #define EXT_SENS_DATA_22 0x5F
demayer 0:6bf0743ece18 128 #define EXT_SENS_DATA_23 0x60
demayer 0:6bf0743ece18 129 #define MOT_DETECT_STATUS 0x61
demayer 0:6bf0743ece18 130 #define I2C_SLV0_DO 0x63
demayer 0:6bf0743ece18 131 #define I2C_SLV1_DO 0x64
demayer 0:6bf0743ece18 132 #define I2C_SLV2_DO 0x65
demayer 0:6bf0743ece18 133 #define I2C_SLV3_DO 0x66
demayer 0:6bf0743ece18 134 #define I2C_MST_DELAY_CTRL 0x67
demayer 0:6bf0743ece18 135 #define SIGNAL_PATH_RESET 0x68
demayer 0:6bf0743ece18 136 #define MOT_DETECT_CTRL 0x69
demayer 0:6bf0743ece18 137 #define USER_CTRL 0x6A // Bit 7 enable DMP, bit 3 reset DMP
demayer 0:6bf0743ece18 138 #define PWR_MGMT_1 0x6B // Device defaults to the SLEEP mode
demayer 0:6bf0743ece18 139 #define PWR_MGMT_2 0x6C
demayer 0:6bf0743ece18 140 #define DMP_BANK 0x6D // Activates a specific bank in the DMP
demayer 0:6bf0743ece18 141 #define DMP_RW_PNT 0x6E // Set read/write pointer to a specific start address in specified DMP bank
demayer 0:6bf0743ece18 142 #define DMP_REG 0x6F // Register in DMP from which to read or to which to write
demayer 0:6bf0743ece18 143 #define DMP_REG_1 0x70
demayer 0:6bf0743ece18 144 #define DMP_REG_2 0x71
demayer 0:6bf0743ece18 145 #define FIFO_COUNTH 0x72
demayer 0:6bf0743ece18 146 #define FIFO_COUNTL 0x73
demayer 0:6bf0743ece18 147 #define FIFO_R_W 0x74
demayer 0:6bf0743ece18 148 #define WHO_AM_I_MPU9250 0x75 // Should return 0x71
demayer 0:6bf0743ece18 149 #define XA_OFFSET_H 0x77
demayer 0:6bf0743ece18 150 #define XA_OFFSET_L 0x78
demayer 0:6bf0743ece18 151 #define YA_OFFSET_H 0x7A
demayer 0:6bf0743ece18 152 #define YA_OFFSET_L 0x7B
demayer 0:6bf0743ece18 153 #define ZA_OFFSET_H 0x7D
demayer 0:6bf0743ece18 154 #define ZA_OFFSET_L 0x7E
demayer 0:6bf0743ece18 155
demayer 0:6bf0743ece18 156 // Using the MSENSR-9250 breakout board, ADO is set to 0
demayer 0:6bf0743ece18 157 // Seven-bit device address is 110100 for ADO = 0 and 110101 for ADO = 1
demayer 0:6bf0743ece18 158 //mbed uses the eight-bit device address, so shift seven-bit addresses left by one!
demayer 0:6bf0743ece18 159 #define ADO 0
demayer 0:6bf0743ece18 160 #if ADO
demayer 0:6bf0743ece18 161 #define MPU9250_ADDRESS 0x69<<1 // Device address when ADO = 1
demayer 0:6bf0743ece18 162 #else
demayer 0:6bf0743ece18 163 #define MPU9250_ADDRESS 0x68<<1 // Device address when ADO = 0
demayer 0:6bf0743ece18 164 #endif
demayer 0:6bf0743ece18 165
demayer 0:6bf0743ece18 166 // Set initial input parameters
demayer 0:6bf0743ece18 167 enum Ascale {
demayer 0:6bf0743ece18 168 AFS_2G = 0,
demayer 0:6bf0743ece18 169 AFS_4G,
demayer 0:6bf0743ece18 170 AFS_8G,
demayer 0:6bf0743ece18 171 AFS_16G
demayer 0:6bf0743ece18 172 };
demayer 0:6bf0743ece18 173
demayer 0:6bf0743ece18 174 enum Gscale {
demayer 0:6bf0743ece18 175 GFS_250DPS = 0,
demayer 0:6bf0743ece18 176 GFS_500DPS,
demayer 0:6bf0743ece18 177 GFS_1000DPS,
demayer 0:6bf0743ece18 178 GFS_2000DPS
demayer 0:6bf0743ece18 179 };
demayer 0:6bf0743ece18 180
demayer 0:6bf0743ece18 181 enum Mscale {
demayer 0:6bf0743ece18 182 MFS_14BITS = 0, // 0.6 mG per LSB
demayer 0:6bf0743ece18 183 MFS_16BITS // 0.15 mG per LSB
demayer 0:6bf0743ece18 184 };
demayer 0:6bf0743ece18 185
demayer 0:6bf0743ece18 186 uint8_t Ascale = AFS_2G; // AFS_2G, AFS_4G, AFS_8G, AFS_16G
demayer 0:6bf0743ece18 187 uint8_t Gscale = GFS_250DPS; // GFS_250DPS, GFS_500DPS, GFS_1000DPS, GFS_2000DPS
demayer 0:6bf0743ece18 188 uint8_t Mscale = MFS_16BITS; // MFS_14BITS or MFS_16BITS, 14-bit or 16-bit magnetometer resolution
demayer 0:6bf0743ece18 189 uint8_t Mmode = 0x06; // Either 8 Hz 0x02) or 100 Hz (0x06) magnetometer data ODR
demayer 0:6bf0743ece18 190 float aRes, gRes, mRes; // scale resolutions per LSB for the sensors
demayer 0:6bf0743ece18 191
demayer 0:6bf0743ece18 192 //Set up I2C, (SDA,SCL)
demayer 0:6bf0743ece18 193 I2C i2c(PB_9, PB_8);
demayer 0:6bf0743ece18 194
demayer 0:6bf0743ece18 195 DigitalOut myled(LED1);
demayer 0:6bf0743ece18 196
demayer 0:6bf0743ece18 197 // Pin definitions
demayer 0:6bf0743ece18 198 int intPin = 12; // These can be changed, 2 and 3 are the Arduinos ext int pins
demayer 0:6bf0743ece18 199
demayer 0:6bf0743ece18 200 int16_t accelCount[3]; // Stores the 16-bit signed accelerometer sensor output
demayer 0:6bf0743ece18 201 int16_t gyroCount[3]; // Stores the 16-bit signed gyro sensor output
demayer 0:6bf0743ece18 202 int16_t magCount[3]; // Stores the 16-bit signed magnetometer sensor output
demayer 0:6bf0743ece18 203 float magCalibration[3] = {0, 0, 0}, magbias[3] = {0, 0, 0}; // Factory mag calibration and mag bias
demayer 0:6bf0743ece18 204 float gyroBias[3] = {0, 0, 0}, accelBias[3] = {0, 0, 0}; // Bias corrections for gyro and accelerometer
demayer 0:6bf0743ece18 205 float ax, ay, az, gx, gy, gz, mx, my, mz; // variables to hold latest sensor data values
demayer 0:6bf0743ece18 206 int16_t tempCount; // Stores the real internal chip temperature in degrees Celsius
demayer 0:6bf0743ece18 207 float temperature;
demayer 0:6bf0743ece18 208 float SelfTest[6];
demayer 0:6bf0743ece18 209
demayer 0:6bf0743ece18 210 int delt_t = 0; // used to control display output rate
demayer 0:6bf0743ece18 211 int _count = 0; // used to control display output rate
demayer 0:6bf0743ece18 212
demayer 0:6bf0743ece18 213 // parameters for 6 DoF sensor fusion calculations
demayer 0:6bf0743ece18 214 float PI = 3.14159265358979323846f;
demayer 0:6bf0743ece18 215 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 0:6bf0743ece18 216 float beta = sqrt(3.0f / 4.0f) * GyroMeasError; // compute beta
demayer 0:6bf0743ece18 217 float GyroMeasDrift = PI * (1.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
demayer 0:6bf0743ece18 218 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 0:6bf0743ece18 219 #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 0:6bf0743ece18 220 #define Ki 0.0f
demayer 0:6bf0743ece18 221
demayer 0:6bf0743ece18 222 float pitch, yaw, roll;
demayer 0:6bf0743ece18 223 float deltat = 0.0f; // integration interval for both filter schemes
demayer 0:6bf0743ece18 224 int lastUpdate = 0, firstUpdate = 0, Now = 0; // used to calculate integration interval // used to calculate integration interval
demayer 0:6bf0743ece18 225 float q[4] = {1.0f, 0.0f, 0.0f, 0.0f}; // vector to hold quaternion
demayer 0:6bf0743ece18 226 float eInt[3] = {0.0f, 0.0f, 0.0f}; // vector to hold integral error for Mahony method
demayer 0:6bf0743ece18 227
demayer 0:6bf0743ece18 228 class MPU9250 {
demayer 0:6bf0743ece18 229
demayer 0:6bf0743ece18 230 protected:
demayer 0:6bf0743ece18 231
demayer 0:6bf0743ece18 232 public:
demayer 0:6bf0743ece18 233 //===================================================================================================================
demayer 0:6bf0743ece18 234 //====== Set of useful function to access acceleratio, gyroscope, and temperature data
demayer 0:6bf0743ece18 235 //===================================================================================================================
demayer 0:6bf0743ece18 236
demayer 0:6bf0743ece18 237 void writeByte(uint8_t address, uint8_t subAddress, uint8_t data)
demayer 0:6bf0743ece18 238 {
demayer 0:6bf0743ece18 239 char data_write[2];
demayer 0:6bf0743ece18 240 data_write[0] = subAddress;
demayer 0:6bf0743ece18 241 data_write[1] = data;
demayer 0:6bf0743ece18 242 i2c.write(address, data_write, 2, 0);
demayer 0:6bf0743ece18 243 }
demayer 0:6bf0743ece18 244
demayer 0:6bf0743ece18 245 char readByte(uint8_t address, uint8_t subAddress)
demayer 0:6bf0743ece18 246 {
demayer 0:6bf0743ece18 247 char data[1]; // `data` will store the register data
demayer 0:6bf0743ece18 248 char data_write[1];
demayer 0:6bf0743ece18 249 data_write[0] = subAddress;
demayer 0:6bf0743ece18 250 i2c.write(address, data_write, 1, 1); // no stop
demayer 0:6bf0743ece18 251 i2c.read(address, data, 1, 0);
demayer 0:6bf0743ece18 252 return data[0];
demayer 0:6bf0743ece18 253 }
demayer 0:6bf0743ece18 254
demayer 0:6bf0743ece18 255 void readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest)
demayer 0:6bf0743ece18 256 {
demayer 0:6bf0743ece18 257 char data[14];
demayer 0:6bf0743ece18 258 char data_write[1];
demayer 0:6bf0743ece18 259 data_write[0] = subAddress;
demayer 0:6bf0743ece18 260 i2c.write(address, data_write, 1, 1); // no stop
demayer 0:6bf0743ece18 261 i2c.read(address, data, count, 0);
demayer 0:6bf0743ece18 262 for(int ii = 0; ii < count; ii++) {
demayer 0:6bf0743ece18 263 dest[ii] = data[ii];
demayer 0:6bf0743ece18 264 }
demayer 0:6bf0743ece18 265 }
demayer 0:6bf0743ece18 266
demayer 0:6bf0743ece18 267
demayer 0:6bf0743ece18 268 void getMres() {
demayer 0:6bf0743ece18 269 switch (Mscale)
demayer 0:6bf0743ece18 270 {
demayer 0:6bf0743ece18 271 // Possible magnetometer scales (and their register bit settings) are:
demayer 0:6bf0743ece18 272 // 14 bit resolution (0) and 16 bit resolution (1)
demayer 0:6bf0743ece18 273 case MFS_14BITS:
demayer 0:6bf0743ece18 274 mRes = 10.0*4219.0/8190.0; // Proper scale to return milliGauss
demayer 0:6bf0743ece18 275 break;
demayer 0:6bf0743ece18 276 case MFS_16BITS:
demayer 0:6bf0743ece18 277 mRes = 10.0*4219.0/32760.0; // Proper scale to return milliGauss
demayer 0:6bf0743ece18 278 break;
demayer 0:6bf0743ece18 279 }
demayer 0:6bf0743ece18 280 }
demayer 0:6bf0743ece18 281
demayer 0:6bf0743ece18 282
demayer 0:6bf0743ece18 283 void getGres() {
demayer 0:6bf0743ece18 284 switch (Gscale)
demayer 0:6bf0743ece18 285 {
demayer 0:6bf0743ece18 286 // Possible gyro scales (and their register bit settings) are:
demayer 0:6bf0743ece18 287 // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS (11).
demayer 0:6bf0743ece18 288 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
demayer 0:6bf0743ece18 289 case GFS_250DPS:
demayer 0:6bf0743ece18 290 gRes = 250.0/32768.0;
demayer 0:6bf0743ece18 291 break;
demayer 0:6bf0743ece18 292 case GFS_500DPS:
demayer 0:6bf0743ece18 293 gRes = 500.0/32768.0;
demayer 0:6bf0743ece18 294 break;
demayer 0:6bf0743ece18 295 case GFS_1000DPS:
demayer 0:6bf0743ece18 296 gRes = 1000.0/32768.0;
demayer 0:6bf0743ece18 297 break;
demayer 0:6bf0743ece18 298 case GFS_2000DPS:
demayer 0:6bf0743ece18 299 gRes = 2000.0/32768.0;
demayer 0:6bf0743ece18 300 break;
demayer 0:6bf0743ece18 301 }
demayer 0:6bf0743ece18 302 }
demayer 0:6bf0743ece18 303
demayer 0:6bf0743ece18 304
demayer 0:6bf0743ece18 305 void getAres() {
demayer 0:6bf0743ece18 306 switch (Ascale)
demayer 0:6bf0743ece18 307 {
demayer 0:6bf0743ece18 308 // Possible accelerometer scales (and their register bit settings) are:
demayer 0:6bf0743ece18 309 // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs (11).
demayer 0:6bf0743ece18 310 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
demayer 0:6bf0743ece18 311 case AFS_2G:
demayer 0:6bf0743ece18 312 aRes = 2.0/32768.0;
demayer 0:6bf0743ece18 313 break;
demayer 0:6bf0743ece18 314 case AFS_4G:
demayer 0:6bf0743ece18 315 aRes = 4.0/32768.0;
demayer 0:6bf0743ece18 316 break;
demayer 0:6bf0743ece18 317 case AFS_8G:
demayer 0:6bf0743ece18 318 aRes = 8.0/32768.0;
demayer 0:6bf0743ece18 319 break;
demayer 0:6bf0743ece18 320 case AFS_16G:
demayer 0:6bf0743ece18 321 aRes = 16.0/32768.0;
demayer 0:6bf0743ece18 322 break;
demayer 0:6bf0743ece18 323 }
demayer 0:6bf0743ece18 324 }
demayer 0:6bf0743ece18 325
demayer 0:6bf0743ece18 326
demayer 0:6bf0743ece18 327 void readAccelData(int16_t * destination)
demayer 0:6bf0743ece18 328 {
demayer 0:6bf0743ece18 329 uint8_t rawData[6]; // x/y/z accel register data stored here
demayer 0:6bf0743ece18 330 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
demayer 0:6bf0743ece18 331 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 0:6bf0743ece18 332 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 0:6bf0743ece18 333 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 0:6bf0743ece18 334 }
demayer 0:6bf0743ece18 335
demayer 0:6bf0743ece18 336 void readGyroData(int16_t * destination)
demayer 0:6bf0743ece18 337 {
demayer 0:6bf0743ece18 338 uint8_t rawData[6]; // x/y/z gyro register data stored here
demayer 0:6bf0743ece18 339 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
demayer 0:6bf0743ece18 340 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 0:6bf0743ece18 341 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 0:6bf0743ece18 342 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 0:6bf0743ece18 343 }
demayer 0:6bf0743ece18 344
demayer 0:6bf0743ece18 345 void readMagData(int16_t * destination)
demayer 0:6bf0743ece18 346 {
demayer 0:6bf0743ece18 347 uint8_t rawData[7]; // x/y/z gyro register data, ST2 register stored here, must read ST2 at end of data acquisition
demayer 0:6bf0743ece18 348 if(readByte(AK8963_ADDRESS, AK8963_ST1) & 0x01) { // wait for magnetometer data ready bit to be set
demayer 0:6bf0743ece18 349 readBytes(AK8963_ADDRESS, AK8963_XOUT_L, 7, &rawData[0]); // Read the six raw data and ST2 registers sequentially into data array
demayer 0:6bf0743ece18 350 uint8_t c = rawData[6]; // End data read by reading ST2 register
demayer 0:6bf0743ece18 351 if(!(c & 0x08)) { // Check if magnetic sensor overflow set, if not then report data
demayer 0:6bf0743ece18 352 destination[0] = (int16_t)(((int16_t)rawData[1] << 8) | rawData[0]); // Turn the MSB and LSB into a signed 16-bit value
demayer 0:6bf0743ece18 353 destination[1] = (int16_t)(((int16_t)rawData[3] << 8) | rawData[2]) ; // Data stored as little Endian
demayer 0:6bf0743ece18 354 destination[2] = (int16_t)(((int16_t)rawData[5] << 8) | rawData[4]) ;
demayer 0:6bf0743ece18 355 }
demayer 0:6bf0743ece18 356 }
demayer 0:6bf0743ece18 357 }
demayer 0:6bf0743ece18 358
demayer 0:6bf0743ece18 359 int16_t readTempData()
demayer 0:6bf0743ece18 360 {
demayer 0:6bf0743ece18 361 uint8_t rawData[2]; // x/y/z gyro register data stored here
demayer 0:6bf0743ece18 362 readBytes(MPU9250_ADDRESS, TEMP_OUT_H, 2, &rawData[0]); // Read the two raw data registers sequentially into data array
demayer 0:6bf0743ece18 363 return (int16_t)(((int16_t)rawData[0]) << 8 | rawData[1]) ; // Turn the MSB and LSB into a 16-bit value
demayer 0:6bf0743ece18 364 }
demayer 0:6bf0743ece18 365
demayer 0:6bf0743ece18 366
demayer 0:6bf0743ece18 367 void resetMPU9250() {
demayer 0:6bf0743ece18 368 // reset device
demayer 0:6bf0743ece18 369 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
demayer 0:6bf0743ece18 370 wait(0.1);
demayer 0:6bf0743ece18 371 }
demayer 0:6bf0743ece18 372
demayer 0:6bf0743ece18 373 void initAK8963(float * destination)
demayer 0:6bf0743ece18 374 {
demayer 0:6bf0743ece18 375 // First extract the factory calibration for each magnetometer axis
demayer 0:6bf0743ece18 376 uint8_t rawData[3]; // x/y/z gyro calibration data stored here
demayer 0:6bf0743ece18 377 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
demayer 0:6bf0743ece18 378 wait(0.01);
demayer 0:6bf0743ece18 379 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x0F); // Enter Fuse ROM access mode
demayer 0:6bf0743ece18 380 wait(0.01);
demayer 0:6bf0743ece18 381 readBytes(AK8963_ADDRESS, AK8963_ASAX, 3, &rawData[0]); // Read the x-, y-, and z-axis calibration values
demayer 0:6bf0743ece18 382 destination[0] = (float)(rawData[0] - 128)/256.0f + 1.0f; // Return x-axis sensitivity adjustment values, etc.
demayer 0:6bf0743ece18 383 destination[1] = (float)(rawData[1] - 128)/256.0f + 1.0f;
demayer 0:6bf0743ece18 384 destination[2] = (float)(rawData[2] - 128)/256.0f + 1.0f;
demayer 0:6bf0743ece18 385 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
demayer 0:6bf0743ece18 386 wait(0.01);
demayer 0:6bf0743ece18 387 // Configure the magnetometer for continuous read and highest resolution
demayer 0:6bf0743ece18 388 // set Mscale bit 4 to 1 (0) to enable 16 (14) bit resolution in CNTL register,
demayer 0:6bf0743ece18 389 // and enable continuous mode data acquisition Mmode (bits [3:0]), 0010 for 8 Hz and 0110 for 100 Hz sample rates
demayer 0:6bf0743ece18 390 writeByte(AK8963_ADDRESS, AK8963_CNTL, Mscale << 4 | Mmode); // Set magnetometer data resolution and sample ODR
demayer 0:6bf0743ece18 391 wait(0.01);
demayer 0:6bf0743ece18 392 }
demayer 0:6bf0743ece18 393
demayer 0:6bf0743ece18 394
demayer 0:6bf0743ece18 395 void initMPU9250()
demayer 0:6bf0743ece18 396 {
demayer 0:6bf0743ece18 397 // Initialize MPU9250 device
demayer 0:6bf0743ece18 398 // wake up device
demayer 0:6bf0743ece18 399 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors
demayer 0:6bf0743ece18 400 wait(0.1); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt
demayer 0:6bf0743ece18 401
demayer 0:6bf0743ece18 402 // get stable time source
demayer 0:6bf0743ece18 403 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01); // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
demayer 0:6bf0743ece18 404
demayer 0:6bf0743ece18 405 // Configure Gyro and Accelerometer
demayer 0:6bf0743ece18 406 // Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively;
demayer 0:6bf0743ece18 407 // DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both
demayer 0:6bf0743ece18 408 // Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate
demayer 0:6bf0743ece18 409 writeByte(MPU9250_ADDRESS, CONFIG, 0x03);
demayer 0:6bf0743ece18 410
demayer 0:6bf0743ece18 411 // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV)
demayer 0:6bf0743ece18 412 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x04); // Use a 200 Hz rate; the same rate set in CONFIG above
demayer 0:6bf0743ece18 413
demayer 0:6bf0743ece18 414 // Set gyroscope full scale range
demayer 0:6bf0743ece18 415 // Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3
demayer 0:6bf0743ece18 416 uint8_t c = readByte(MPU9250_ADDRESS, GYRO_CONFIG);
demayer 0:6bf0743ece18 417 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
demayer 0:6bf0743ece18 418 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
demayer 0:6bf0743ece18 419 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c | Gscale << 3); // Set full scale range for the gyro
demayer 0:6bf0743ece18 420
demayer 0:6bf0743ece18 421 // Set accelerometer configuration
demayer 0:6bf0743ece18 422 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG);
demayer 0:6bf0743ece18 423 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
demayer 0:6bf0743ece18 424 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
demayer 0:6bf0743ece18 425 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c | Ascale << 3); // Set full scale range for the accelerometer
demayer 0:6bf0743ece18 426
demayer 0:6bf0743ece18 427 // Set accelerometer sample rate configuration
demayer 0:6bf0743ece18 428 // It is possible to get a 4 kHz sample rate from the accelerometer by choosing 1 for
demayer 0:6bf0743ece18 429 // accel_fchoice_b bit [3]; in this case the bandwidth is 1.13 kHz
demayer 0:6bf0743ece18 430 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG2);
demayer 0:6bf0743ece18 431 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c & ~0x0F); // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0])
demayer 0:6bf0743ece18 432 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c | 0x03); // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz
demayer 0:6bf0743ece18 433
demayer 0:6bf0743ece18 434 // The accelerometer, gyro, and thermometer are set to 1 kHz sample rates,
demayer 0:6bf0743ece18 435 // but all these rates are further reduced by a factor of 5 to 200 Hz because of the SMPLRT_DIV setting
demayer 0:6bf0743ece18 436
demayer 0:6bf0743ece18 437 // Configure Interrupts and Bypass Enable
demayer 0:6bf0743ece18 438 // Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips
demayer 0:6bf0743ece18 439 // can join the I2C bus and all can be controlled by the Arduino as master
demayer 0:6bf0743ece18 440 writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x22);
demayer 0:6bf0743ece18 441 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt
demayer 0:6bf0743ece18 442 }
demayer 0:6bf0743ece18 443
demayer 0:6bf0743ece18 444 // Function which accumulates gyro and accelerometer data after device initialization. It calculates the average
demayer 0:6bf0743ece18 445 // of the at-rest readings and then loads the resulting offsets into accelerometer and gyro bias registers.
demayer 0:6bf0743ece18 446 void calibrateMPU9250(float * dest1, float * dest2)
demayer 0:6bf0743ece18 447 {
demayer 0:6bf0743ece18 448 uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data
demayer 0:6bf0743ece18 449 uint16_t ii, packet_count, fifo_count;
demayer 0:6bf0743ece18 450 int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
demayer 0:6bf0743ece18 451
demayer 0:6bf0743ece18 452 // reset device, reset all registers, clear gyro and accelerometer bias registers
demayer 0:6bf0743ece18 453 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
demayer 0:6bf0743ece18 454 wait(0.1);
demayer 0:6bf0743ece18 455
demayer 0:6bf0743ece18 456 // get stable time source
demayer 0:6bf0743ece18 457 // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
demayer 0:6bf0743ece18 458 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01);
demayer 0:6bf0743ece18 459 writeByte(MPU9250_ADDRESS, PWR_MGMT_2, 0x00);
demayer 0:6bf0743ece18 460 wait(0.2);
demayer 0:6bf0743ece18 461
demayer 0:6bf0743ece18 462 // Configure device for bias calculation
demayer 0:6bf0743ece18 463 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts
demayer 0:6bf0743ece18 464 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable FIFO
demayer 0:6bf0743ece18 465 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source
demayer 0:6bf0743ece18 466 writeByte(MPU9250_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master
demayer 0:6bf0743ece18 467 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes
demayer 0:6bf0743ece18 468 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP
demayer 0:6bf0743ece18 469 wait(0.015);
demayer 0:6bf0743ece18 470
demayer 0:6bf0743ece18 471 // Configure MPU9250 gyro and accelerometer for bias calculation
demayer 0:6bf0743ece18 472 writeByte(MPU9250_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz
demayer 0:6bf0743ece18 473 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz
demayer 0:6bf0743ece18 474 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity
demayer 0:6bf0743ece18 475 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity
demayer 0:6bf0743ece18 476
demayer 0:6bf0743ece18 477 uint16_t gyrosensitivity = 131; // = 131 LSB/degrees/sec
demayer 0:6bf0743ece18 478 uint16_t accelsensitivity = 16384; // = 16384 LSB/g
demayer 0:6bf0743ece18 479
demayer 0:6bf0743ece18 480 // Configure FIFO to capture accelerometer and gyro data for bias calculation
demayer 0:6bf0743ece18 481 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x40); // Enable FIFO
demayer 0:6bf0743ece18 482 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9250)
demayer 0:6bf0743ece18 483 wait(0.04); // accumulate 40 samples in 80 milliseconds = 480 bytes
demayer 0:6bf0743ece18 484
demayer 0:6bf0743ece18 485 // At end of sample accumulation, turn off FIFO sensor read
demayer 0:6bf0743ece18 486 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO
demayer 0:6bf0743ece18 487 readBytes(MPU9250_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count
demayer 0:6bf0743ece18 488 fifo_count = ((uint16_t)data[0] << 8) | data[1];
demayer 0:6bf0743ece18 489 packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging
demayer 0:6bf0743ece18 490
demayer 0:6bf0743ece18 491 for (ii = 0; ii < packet_count; ii++) {
demayer 0:6bf0743ece18 492 int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0};
demayer 0:6bf0743ece18 493 readBytes(MPU9250_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging
demayer 0:6bf0743ece18 494 accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO
demayer 0:6bf0743ece18 495 accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ;
demayer 0:6bf0743ece18 496 accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ;
demayer 0:6bf0743ece18 497 gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ;
demayer 0:6bf0743ece18 498 gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ;
demayer 0:6bf0743ece18 499 gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ;
demayer 0:6bf0743ece18 500
demayer 0:6bf0743ece18 501 accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases
demayer 0:6bf0743ece18 502 accel_bias[1] += (int32_t) accel_temp[1];
demayer 0:6bf0743ece18 503 accel_bias[2] += (int32_t) accel_temp[2];
demayer 0:6bf0743ece18 504 gyro_bias[0] += (int32_t) gyro_temp[0];
demayer 0:6bf0743ece18 505 gyro_bias[1] += (int32_t) gyro_temp[1];
demayer 0:6bf0743ece18 506 gyro_bias[2] += (int32_t) gyro_temp[2];
demayer 0:6bf0743ece18 507
demayer 0:6bf0743ece18 508 }
demayer 0:6bf0743ece18 509 accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases
demayer 0:6bf0743ece18 510 accel_bias[1] /= (int32_t) packet_count;
demayer 0:6bf0743ece18 511 accel_bias[2] /= (int32_t) packet_count;
demayer 0:6bf0743ece18 512 gyro_bias[0] /= (int32_t) packet_count;
demayer 0:6bf0743ece18 513 gyro_bias[1] /= (int32_t) packet_count;
demayer 0:6bf0743ece18 514 gyro_bias[2] /= (int32_t) packet_count;
demayer 0:6bf0743ece18 515
demayer 0:6bf0743ece18 516 if(accel_bias[2] > 0L) {accel_bias[2] -= (int32_t) accelsensitivity;} // Remove gravity from the z-axis accelerometer bias calculation
demayer 0:6bf0743ece18 517 else {accel_bias[2] += (int32_t) accelsensitivity;}
demayer 0:6bf0743ece18 518
demayer 0:6bf0743ece18 519 // Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup
demayer 0:6bf0743ece18 520 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 0:6bf0743ece18 521 data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
demayer 0:6bf0743ece18 522 data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF;
demayer 0:6bf0743ece18 523 data[3] = (-gyro_bias[1]/4) & 0xFF;
demayer 0:6bf0743ece18 524 data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF;
demayer 0:6bf0743ece18 525 data[5] = (-gyro_bias[2]/4) & 0xFF;
demayer 0:6bf0743ece18 526
demayer 0:6bf0743ece18 527 /// Push gyro biases to hardware registers
demayer 0:6bf0743ece18 528 /* writeByte(MPU9250_ADDRESS, XG_OFFSET_H, data[0]);
demayer 0:6bf0743ece18 529 writeByte(MPU9250_ADDRESS, XG_OFFSET_L, data[1]);
demayer 0:6bf0743ece18 530 writeByte(MPU9250_ADDRESS, YG_OFFSET_H, data[2]);
demayer 0:6bf0743ece18 531 writeByte(MPU9250_ADDRESS, YG_OFFSET_L, data[3]);
demayer 0:6bf0743ece18 532 writeByte(MPU9250_ADDRESS, ZG_OFFSET_H, data[4]);
demayer 0:6bf0743ece18 533 writeByte(MPU9250_ADDRESS, ZG_OFFSET_L, data[5]);
demayer 0:6bf0743ece18 534 */
demayer 0:6bf0743ece18 535 dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction
demayer 0:6bf0743ece18 536 dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity;
demayer 0:6bf0743ece18 537 dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity;
demayer 0:6bf0743ece18 538
demayer 0:6bf0743ece18 539 // Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain
demayer 0:6bf0743ece18 540 // factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold
demayer 0:6bf0743ece18 541 // non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature
demayer 0:6bf0743ece18 542 // compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that
demayer 0:6bf0743ece18 543 // the accelerometer biases calculated above must be divided by 8.
demayer 0:6bf0743ece18 544
demayer 0:6bf0743ece18 545 int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases
demayer 0:6bf0743ece18 546 readBytes(MPU9250_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values
demayer 0:6bf0743ece18 547 accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1];
demayer 0:6bf0743ece18 548 readBytes(MPU9250_ADDRESS, YA_OFFSET_H, 2, &data[0]);
demayer 0:6bf0743ece18 549 accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1];
demayer 0:6bf0743ece18 550 readBytes(MPU9250_ADDRESS, ZA_OFFSET_H, 2, &data[0]);
demayer 0:6bf0743ece18 551 accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1];
demayer 0:6bf0743ece18 552
demayer 0:6bf0743ece18 553 uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers
demayer 0:6bf0743ece18 554 uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis
demayer 0:6bf0743ece18 555
demayer 0:6bf0743ece18 556 for(ii = 0; ii < 3; ii++) {
demayer 0:6bf0743ece18 557 if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit
demayer 0:6bf0743ece18 558 }
demayer 0:6bf0743ece18 559
demayer 0:6bf0743ece18 560 // Construct total accelerometer bias, including calculated average accelerometer bias from above
demayer 0:6bf0743ece18 561 accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale)
demayer 0:6bf0743ece18 562 accel_bias_reg[1] -= (accel_bias[1]/8);
demayer 0:6bf0743ece18 563 accel_bias_reg[2] -= (accel_bias[2]/8);
demayer 0:6bf0743ece18 564
demayer 0:6bf0743ece18 565 data[0] = (accel_bias_reg[0] >> 8) & 0xFF;
demayer 0:6bf0743ece18 566 data[1] = (accel_bias_reg[0]) & 0xFF;
demayer 0:6bf0743ece18 567 data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers
demayer 0:6bf0743ece18 568 data[2] = (accel_bias_reg[1] >> 8) & 0xFF;
demayer 0:6bf0743ece18 569 data[3] = (accel_bias_reg[1]) & 0xFF;
demayer 0:6bf0743ece18 570 data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers
demayer 0:6bf0743ece18 571 data[4] = (accel_bias_reg[2] >> 8) & 0xFF;
demayer 0:6bf0743ece18 572 data[5] = (accel_bias_reg[2]) & 0xFF;
demayer 0:6bf0743ece18 573 data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers
demayer 0:6bf0743ece18 574
demayer 0:6bf0743ece18 575 // Apparently this is not working for the acceleration biases in the MPU-9250
demayer 0:6bf0743ece18 576 // Are we handling the temperature correction bit properly?
demayer 0:6bf0743ece18 577 // Push accelerometer biases to hardware registers
demayer 0:6bf0743ece18 578 /* writeByte(MPU9250_ADDRESS, XA_OFFSET_H, data[0]);
demayer 0:6bf0743ece18 579 writeByte(MPU9250_ADDRESS, XA_OFFSET_L, data[1]);
demayer 0:6bf0743ece18 580 writeByte(MPU9250_ADDRESS, YA_OFFSET_H, data[2]);
demayer 0:6bf0743ece18 581 writeByte(MPU9250_ADDRESS, YA_OFFSET_L, data[3]);
demayer 0:6bf0743ece18 582 writeByte(MPU9250_ADDRESS, ZA_OFFSET_H, data[4]);
demayer 0:6bf0743ece18 583 writeByte(MPU9250_ADDRESS, ZA_OFFSET_L, data[5]);
demayer 0:6bf0743ece18 584 */
demayer 0:6bf0743ece18 585 // Output scaled accelerometer biases for manual subtraction in the main program
demayer 0:6bf0743ece18 586 dest2[0] = (float)accel_bias[0]/(float)accelsensitivity;
demayer 0:6bf0743ece18 587 dest2[1] = (float)accel_bias[1]/(float)accelsensitivity;
demayer 0:6bf0743ece18 588 dest2[2] = (float)accel_bias[2]/(float)accelsensitivity;
demayer 0:6bf0743ece18 589 }
demayer 0:6bf0743ece18 590
demayer 0:6bf0743ece18 591
demayer 0:6bf0743ece18 592 // Accelerometer and gyroscope self test; check calibration wrt factory settings
demayer 0:6bf0743ece18 593 void MPU9250SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass
demayer 0:6bf0743ece18 594 {
demayer 0:6bf0743ece18 595 uint8_t rawData[6] = {0, 0, 0, 0, 0, 0};
demayer 0:6bf0743ece18 596 uint8_t selfTest[6];
demayer 0:6bf0743ece18 597 int16_t gAvg[3], aAvg[3], aSTAvg[3], gSTAvg[3];
demayer 0:6bf0743ece18 598 float factoryTrim[6];
demayer 0:6bf0743ece18 599 uint8_t FS = 0;
demayer 0:6bf0743ece18 600
demayer 0:6bf0743ece18 601 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz
demayer 0:6bf0743ece18 602 writeByte(MPU9250_ADDRESS, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz
demayer 0:6bf0743ece18 603 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 1<<FS); // Set full scale range for the gyro to 250 dps
demayer 0:6bf0743ece18 604 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz
demayer 0:6bf0743ece18 605 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 1<<FS); // Set full scale range for the accelerometer to 2 g
demayer 0:6bf0743ece18 606
demayer 0:6bf0743ece18 607 for( int ii = 0; ii < 200; ii++) { // get average current values of gyro and acclerometer
demayer 0:6bf0743ece18 608
demayer 0:6bf0743ece18 609 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
demayer 0:6bf0743ece18 610 aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 0:6bf0743ece18 611 aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 0:6bf0743ece18 612 aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 0:6bf0743ece18 613
demayer 0:6bf0743ece18 614 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
demayer 0:6bf0743ece18 615 gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 0:6bf0743ece18 616 gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 0:6bf0743ece18 617 gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 0:6bf0743ece18 618 }
demayer 0:6bf0743ece18 619
demayer 0:6bf0743ece18 620 for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average current readings
demayer 0:6bf0743ece18 621 aAvg[ii] /= 200;
demayer 0:6bf0743ece18 622 gAvg[ii] /= 200;
demayer 0:6bf0743ece18 623 }
demayer 0:6bf0743ece18 624
demayer 0:6bf0743ece18 625 // Configure the accelerometer for self-test
demayer 0:6bf0743ece18 626 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g
demayer 0:6bf0743ece18 627 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
demayer 0:6bf0743ece18 628 wait(0.025); // Delay a while to let the device stabilize
demayer 0:6bf0743ece18 629
demayer 0:6bf0743ece18 630 for( int ii = 0; ii < 200; ii++) { // get average self-test values of gyro and acclerometer
demayer 0:6bf0743ece18 631
demayer 0:6bf0743ece18 632 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
demayer 0:6bf0743ece18 633 aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 0:6bf0743ece18 634 aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 0:6bf0743ece18 635 aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 0:6bf0743ece18 636
demayer 0:6bf0743ece18 637 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
demayer 0:6bf0743ece18 638 gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 0:6bf0743ece18 639 gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 0:6bf0743ece18 640 gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 0:6bf0743ece18 641 }
demayer 0:6bf0743ece18 642
demayer 0:6bf0743ece18 643 for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average self-test readings
demayer 0:6bf0743ece18 644 aSTAvg[ii] /= 200;
demayer 0:6bf0743ece18 645 gSTAvg[ii] /= 200;
demayer 0:6bf0743ece18 646 }
demayer 0:6bf0743ece18 647
demayer 0:6bf0743ece18 648 // Configure the gyro and accelerometer for normal operation
demayer 0:6bf0743ece18 649 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00);
demayer 0:6bf0743ece18 650 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00);
demayer 0:6bf0743ece18 651 wait(0.025); // Delay a while to let the device stabilize
demayer 0:6bf0743ece18 652
demayer 0:6bf0743ece18 653 // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg
demayer 0:6bf0743ece18 654 selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results
demayer 0:6bf0743ece18 655 selfTest[1] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_ACCEL); // Y-axis accel self-test results
demayer 0:6bf0743ece18 656 selfTest[2] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_ACCEL); // Z-axis accel self-test results
demayer 0:6bf0743ece18 657 selfTest[3] = readByte(MPU9250_ADDRESS, SELF_TEST_X_GYRO); // X-axis gyro self-test results
demayer 0:6bf0743ece18 658 selfTest[4] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_GYRO); // Y-axis gyro self-test results
demayer 0:6bf0743ece18 659 selfTest[5] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_GYRO); // Z-axis gyro self-test results
demayer 0:6bf0743ece18 660
demayer 0:6bf0743ece18 661 // Retrieve factory self-test value from self-test code reads
demayer 0:6bf0743ece18 662 factoryTrim[0] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation
demayer 0:6bf0743ece18 663 factoryTrim[1] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation
demayer 0:6bf0743ece18 664 factoryTrim[2] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation
demayer 0:6bf0743ece18 665 factoryTrim[3] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation
demayer 0:6bf0743ece18 666 factoryTrim[4] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation
demayer 0:6bf0743ece18 667 factoryTrim[5] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation
demayer 0:6bf0743ece18 668
demayer 0:6bf0743ece18 669 // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response
demayer 0:6bf0743ece18 670 // To get percent, must multiply by 100
demayer 0:6bf0743ece18 671 for (int i = 0; i < 3; i++) {
demayer 0:6bf0743ece18 672 destination[i] = 100.0*((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i]; // Report percent differences
demayer 0:6bf0743ece18 673 destination[i+3] = 100.0*((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3]; // Report percent differences
demayer 0:6bf0743ece18 674 }
demayer 0:6bf0743ece18 675
demayer 0:6bf0743ece18 676 }
demayer 0:6bf0743ece18 677
demayer 0:6bf0743ece18 678
demayer 0:6bf0743ece18 679
demayer 0:6bf0743ece18 680 // Implementation of Sebastian Madgwick's "...efficient orientation filter for... inertial/magnetic sensor arrays"
demayer 0:6bf0743ece18 681 // (see http://www.x-io.co.uk/category/open-source/ for examples and more details)
demayer 0:6bf0743ece18 682 // which fuses acceleration, rotation rate, and magnetic moments to produce a quaternion-based estimate of absolute
demayer 0:6bf0743ece18 683 // device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc.
demayer 0:6bf0743ece18 684 // The performance of the orientation filter is at least as good as conventional Kalman-based filtering algorithms
demayer 0:6bf0743ece18 685 // but is much less computationally intensive---it can be performed on a 3.3 V Pro Mini operating at 8 MHz!
demayer 0:6bf0743ece18 686 void MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
demayer 0:6bf0743ece18 687 {
demayer 0:6bf0743ece18 688 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
demayer 0:6bf0743ece18 689 float norm;
demayer 0:6bf0743ece18 690 float hx, hy, _2bx, _2bz;
demayer 0:6bf0743ece18 691 float s1, s2, s3, s4;
demayer 0:6bf0743ece18 692 float qDot1, qDot2, qDot3, qDot4;
demayer 0:6bf0743ece18 693
demayer 0:6bf0743ece18 694 // Auxiliary variables to avoid repeated arithmetic
demayer 0:6bf0743ece18 695 float _2q1mx;
demayer 0:6bf0743ece18 696 float _2q1my;
demayer 0:6bf0743ece18 697 float _2q1mz;
demayer 0:6bf0743ece18 698 float _2q2mx;
demayer 0:6bf0743ece18 699 float _4bx;
demayer 0:6bf0743ece18 700 float _4bz;
demayer 0:6bf0743ece18 701 float _2q1 = 2.0f * q1;
demayer 0:6bf0743ece18 702 float _2q2 = 2.0f * q2;
demayer 0:6bf0743ece18 703 float _2q3 = 2.0f * q3;
demayer 0:6bf0743ece18 704 float _2q4 = 2.0f * q4;
demayer 0:6bf0743ece18 705 float _2q1q3 = 2.0f * q1 * q3;
demayer 0:6bf0743ece18 706 float _2q3q4 = 2.0f * q3 * q4;
demayer 0:6bf0743ece18 707 float q1q1 = q1 * q1;
demayer 0:6bf0743ece18 708 float q1q2 = q1 * q2;
demayer 0:6bf0743ece18 709 float q1q3 = q1 * q3;
demayer 0:6bf0743ece18 710 float q1q4 = q1 * q4;
demayer 0:6bf0743ece18 711 float q2q2 = q2 * q2;
demayer 0:6bf0743ece18 712 float q2q3 = q2 * q3;
demayer 0:6bf0743ece18 713 float q2q4 = q2 * q4;
demayer 0:6bf0743ece18 714 float q3q3 = q3 * q3;
demayer 0:6bf0743ece18 715 float q3q4 = q3 * q4;
demayer 0:6bf0743ece18 716 float q4q4 = q4 * q4;
demayer 0:6bf0743ece18 717
demayer 0:6bf0743ece18 718 // Normalise accelerometer measurement
demayer 0:6bf0743ece18 719 norm = sqrt(ax * ax + ay * ay + az * az);
demayer 0:6bf0743ece18 720 if (norm == 0.0f) return; // handle NaN
demayer 0:6bf0743ece18 721 norm = 1.0f/norm;
demayer 0:6bf0743ece18 722 ax *= norm;
demayer 0:6bf0743ece18 723 ay *= norm;
demayer 0:6bf0743ece18 724 az *= norm;
demayer 0:6bf0743ece18 725
demayer 0:6bf0743ece18 726 // Normalise magnetometer measurement
demayer 0:6bf0743ece18 727 norm = sqrt(mx * mx + my * my + mz * mz);
demayer 0:6bf0743ece18 728 if (norm == 0.0f) return; // handle NaN
demayer 0:6bf0743ece18 729 norm = 1.0f/norm;
demayer 0:6bf0743ece18 730 mx *= norm;
demayer 0:6bf0743ece18 731 my *= norm;
demayer 0:6bf0743ece18 732 mz *= norm;
demayer 0:6bf0743ece18 733
demayer 0:6bf0743ece18 734 // Reference direction of Earth's magnetic field
demayer 0:6bf0743ece18 735 _2q1mx = 2.0f * q1 * mx;
demayer 0:6bf0743ece18 736 _2q1my = 2.0f * q1 * my;
demayer 0:6bf0743ece18 737 _2q1mz = 2.0f * q1 * mz;
demayer 0:6bf0743ece18 738 _2q2mx = 2.0f * q2 * mx;
demayer 0:6bf0743ece18 739 hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4;
demayer 0:6bf0743ece18 740 hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4;
demayer 0:6bf0743ece18 741 _2bx = sqrt(hx * hx + hy * hy);
demayer 0:6bf0743ece18 742 _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4;
demayer 0:6bf0743ece18 743 _4bx = 2.0f * _2bx;
demayer 0:6bf0743ece18 744 _4bz = 2.0f * _2bz;
demayer 0:6bf0743ece18 745
demayer 0:6bf0743ece18 746 // Gradient decent algorithm corrective step
demayer 0:6bf0743ece18 747 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 0:6bf0743ece18 748 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 0:6bf0743ece18 749 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 0:6bf0743ece18 750 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 0:6bf0743ece18 751 norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4); // normalise step magnitude
demayer 0:6bf0743ece18 752 norm = 1.0f/norm;
demayer 0:6bf0743ece18 753 s1 *= norm;
demayer 0:6bf0743ece18 754 s2 *= norm;
demayer 0:6bf0743ece18 755 s3 *= norm;
demayer 0:6bf0743ece18 756 s4 *= norm;
demayer 0:6bf0743ece18 757
demayer 0:6bf0743ece18 758 // Compute rate of change of quaternion
demayer 0:6bf0743ece18 759 qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1;
demayer 0:6bf0743ece18 760 qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2;
demayer 0:6bf0743ece18 761 qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3;
demayer 0:6bf0743ece18 762 qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4;
demayer 0:6bf0743ece18 763
demayer 0:6bf0743ece18 764 // Integrate to yield quaternion
demayer 0:6bf0743ece18 765 q1 += qDot1 * deltat;
demayer 0:6bf0743ece18 766 q2 += qDot2 * deltat;
demayer 0:6bf0743ece18 767 q3 += qDot3 * deltat;
demayer 0:6bf0743ece18 768 q4 += qDot4 * deltat;
demayer 0:6bf0743ece18 769 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion
demayer 0:6bf0743ece18 770 norm = 1.0f/norm;
demayer 0:6bf0743ece18 771 q[0] = q1 * norm;
demayer 0:6bf0743ece18 772 q[1] = q2 * norm;
demayer 0:6bf0743ece18 773 q[2] = q3 * norm;
demayer 0:6bf0743ece18 774 q[3] = q4 * norm;
demayer 0:6bf0743ece18 775
demayer 0:6bf0743ece18 776 }
demayer 0:6bf0743ece18 777
demayer 0:6bf0743ece18 778
demayer 0:6bf0743ece18 779
demayer 0:6bf0743ece18 780 // Similar to Madgwick scheme but uses proportional and integral filtering on the error between estimated reference vectors and
demayer 0:6bf0743ece18 781 // measured ones.
demayer 0:6bf0743ece18 782 void MahonyQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
demayer 0:6bf0743ece18 783 {
demayer 0:6bf0743ece18 784 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
demayer 0:6bf0743ece18 785 float norm;
demayer 0:6bf0743ece18 786 float hx, hy, bx, bz;
demayer 0:6bf0743ece18 787 float vx, vy, vz, wx, wy, wz;
demayer 0:6bf0743ece18 788 float ex, ey, ez;
demayer 0:6bf0743ece18 789 float pa, pb, pc;
demayer 0:6bf0743ece18 790
demayer 0:6bf0743ece18 791 // Auxiliary variables to avoid repeated arithmetic
demayer 0:6bf0743ece18 792 float q1q1 = q1 * q1;
demayer 0:6bf0743ece18 793 float q1q2 = q1 * q2;
demayer 0:6bf0743ece18 794 float q1q3 = q1 * q3;
demayer 0:6bf0743ece18 795 float q1q4 = q1 * q4;
demayer 0:6bf0743ece18 796 float q2q2 = q2 * q2;
demayer 0:6bf0743ece18 797 float q2q3 = q2 * q3;
demayer 0:6bf0743ece18 798 float q2q4 = q2 * q4;
demayer 0:6bf0743ece18 799 float q3q3 = q3 * q3;
demayer 0:6bf0743ece18 800 float q3q4 = q3 * q4;
demayer 0:6bf0743ece18 801 float q4q4 = q4 * q4;
demayer 0:6bf0743ece18 802
demayer 0:6bf0743ece18 803 // Normalise accelerometer measurement
demayer 0:6bf0743ece18 804 norm = sqrt(ax * ax + ay * ay + az * az);
demayer 0:6bf0743ece18 805 if (norm == 0.0f) return; // handle NaN
demayer 0:6bf0743ece18 806 norm = 1.0f / norm; // use reciprocal for division
demayer 0:6bf0743ece18 807 ax *= norm;
demayer 0:6bf0743ece18 808 ay *= norm;
demayer 0:6bf0743ece18 809 az *= norm;
demayer 0:6bf0743ece18 810
demayer 0:6bf0743ece18 811 // Normalise magnetometer measurement
demayer 0:6bf0743ece18 812 norm = sqrt(mx * mx + my * my + mz * mz);
demayer 0:6bf0743ece18 813 if (norm == 0.0f) return; // handle NaN
demayer 0:6bf0743ece18 814 norm = 1.0f / norm; // use reciprocal for division
demayer 0:6bf0743ece18 815 mx *= norm;
demayer 0:6bf0743ece18 816 my *= norm;
demayer 0:6bf0743ece18 817 mz *= norm;
demayer 0:6bf0743ece18 818
demayer 0:6bf0743ece18 819 // Reference direction of Earth's magnetic field
demayer 0:6bf0743ece18 820 hx = 2.0f * mx * (0.5f - q3q3 - q4q4) + 2.0f * my * (q2q3 - q1q4) + 2.0f * mz * (q2q4 + q1q3);
demayer 0:6bf0743ece18 821 hy = 2.0f * mx * (q2q3 + q1q4) + 2.0f * my * (0.5f - q2q2 - q4q4) + 2.0f * mz * (q3q4 - q1q2);
demayer 0:6bf0743ece18 822 bx = sqrt((hx * hx) + (hy * hy));
demayer 0:6bf0743ece18 823 bz = 2.0f * mx * (q2q4 - q1q3) + 2.0f * my * (q3q4 + q1q2) + 2.0f * mz * (0.5f - q2q2 - q3q3);
demayer 0:6bf0743ece18 824
demayer 0:6bf0743ece18 825 // Estimated direction of gravity and magnetic field
demayer 0:6bf0743ece18 826 vx = 2.0f * (q2q4 - q1q3);
demayer 0:6bf0743ece18 827 vy = 2.0f * (q1q2 + q3q4);
demayer 0:6bf0743ece18 828 vz = q1q1 - q2q2 - q3q3 + q4q4;
demayer 0:6bf0743ece18 829 wx = 2.0f * bx * (0.5f - q3q3 - q4q4) + 2.0f * bz * (q2q4 - q1q3);
demayer 0:6bf0743ece18 830 wy = 2.0f * bx * (q2q3 - q1q4) + 2.0f * bz * (q1q2 + q3q4);
demayer 0:6bf0743ece18 831 wz = 2.0f * bx * (q1q3 + q2q4) + 2.0f * bz * (0.5f - q2q2 - q3q3);
demayer 0:6bf0743ece18 832
demayer 0:6bf0743ece18 833 // Error is cross product between estimated direction and measured direction of gravity
demayer 0:6bf0743ece18 834 ex = (ay * vz - az * vy) + (my * wz - mz * wy);
demayer 0:6bf0743ece18 835 ey = (az * vx - ax * vz) + (mz * wx - mx * wz);
demayer 0:6bf0743ece18 836 ez = (ax * vy - ay * vx) + (mx * wy - my * wx);
demayer 0:6bf0743ece18 837 if (Ki > 0.0f)
demayer 0:6bf0743ece18 838 {
demayer 0:6bf0743ece18 839 eInt[0] += ex; // accumulate integral error
demayer 0:6bf0743ece18 840 eInt[1] += ey;
demayer 0:6bf0743ece18 841 eInt[2] += ez;
demayer 0:6bf0743ece18 842 }
demayer 0:6bf0743ece18 843 else
demayer 0:6bf0743ece18 844 {
demayer 0:6bf0743ece18 845 eInt[0] = 0.0f; // prevent integral wind up
demayer 0:6bf0743ece18 846 eInt[1] = 0.0f;
demayer 0:6bf0743ece18 847 eInt[2] = 0.0f;
demayer 0:6bf0743ece18 848 }
demayer 0:6bf0743ece18 849
demayer 0:6bf0743ece18 850 // Apply feedback terms
demayer 0:6bf0743ece18 851 gx = gx + Kp * ex + Ki * eInt[0];
demayer 0:6bf0743ece18 852 gy = gy + Kp * ey + Ki * eInt[1];
demayer 0:6bf0743ece18 853 gz = gz + Kp * ez + Ki * eInt[2];
demayer 0:6bf0743ece18 854
demayer 0:6bf0743ece18 855 // Integrate rate of change of quaternion
demayer 0:6bf0743ece18 856 pa = q2;
demayer 0:6bf0743ece18 857 pb = q3;
demayer 0:6bf0743ece18 858 pc = q4;
demayer 0:6bf0743ece18 859 q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * deltat);
demayer 0:6bf0743ece18 860 q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * deltat);
demayer 0:6bf0743ece18 861 q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * deltat);
demayer 0:6bf0743ece18 862 q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * deltat);
demayer 0:6bf0743ece18 863
demayer 0:6bf0743ece18 864 // Normalise quaternion
demayer 0:6bf0743ece18 865 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);
demayer 0:6bf0743ece18 866 norm = 1.0f / norm;
demayer 0:6bf0743ece18 867 q[0] = q1 * norm;
demayer 0:6bf0743ece18 868 q[1] = q2 * norm;
demayer 0:6bf0743ece18 869 q[2] = q3 * norm;
demayer 0:6bf0743ece18 870 q[3] = q4 * norm;
demayer 0:6bf0743ece18 871
demayer 0:6bf0743ece18 872 }
demayer 0:6bf0743ece18 873 };
demayer 0:6bf0743ece18 874 #endif