Suchakhree Srisukprom / Mbed 2 deprecated Test_Megre

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Dependencies:   mbed

MPU9250.h@0:238df339023b, 2015-12-07 (annotated)

Committer:
Suchakhree
Date:
Mon Dec 07 12:20:46 2015 +0000
Revision:
0:238df339023b
nn

Who changed what in which revision?

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Suchakhree 0:238df339023b 1 /*****
Suchakhree 0:238df339023b 2 Library based on MPU-9250_Snowda library. It has been modified by Josué Olmeda Castelló for imasD Tecnología. It uses the
Suchakhree 0:238df339023b 3 mbed I2C class for comunications between the sensor and the master controller.
Suchakhree 0:238df339023b 4 Methods related with data filtering have not been tested.
Suchakhree 0:238df339023b 5 AD0 should be connected to GND.
Suchakhree 0:238df339023b 6 04/05/2015
Suchakhree 0:238df339023b 7 *****/
Suchakhree 0:238df339023b 8
Suchakhree 0:238df339023b 9 #ifndef MPU9250_H
Suchakhree 0:238df339023b 10 #define MPU9250_H
Suchakhree 0:238df339023b 11
Suchakhree 0:238df339023b 12 #include "mbed.h"
Suchakhree 0:238df339023b 13 #include "math.h"
Suchakhree 0:238df339023b 14
Suchakhree 0:238df339023b 15 #define M_PI 3.14159265358979323846
Suchakhree 0:238df339023b 16
Suchakhree 0:238df339023b 17 // 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
Suchakhree 0:238df339023b 18 // above document; the MPU9250 and MPU9150 are virtually identical but the latter has a different register map
Suchakhree 0:238df339023b 19 //
Suchakhree 0:238df339023b 20 //Magnetometer Registers
Suchakhree 0:238df339023b 21 #define AK8963_ADDRESS 0x0C<<1
Suchakhree 0:238df339023b 22 #define WHO_AM_I_AK8963 0x00 // should return 0x48
Suchakhree 0:238df339023b 23 #define INFO 0x01
Suchakhree 0:238df339023b 24 #define AK8963_ST1 0x02 // data ready status bit 0
Suchakhree 0:238df339023b 25 #define AK8963_XOUT_L 0x03 // data
Suchakhree 0:238df339023b 26 #define AK8963_XOUT_H 0x04
Suchakhree 0:238df339023b 27 #define AK8963_YOUT_L 0x05
Suchakhree 0:238df339023b 28 #define AK8963_YOUT_H 0x06
Suchakhree 0:238df339023b 29 #define AK8963_ZOUT_L 0x07
Suchakhree 0:238df339023b 30 #define AK8963_ZOUT_H 0x08
Suchakhree 0:238df339023b 31 #define AK8963_ST2 0x09 // Data overflow bit 3 and data read error status bit 2
Suchakhree 0:238df339023b 32 #define AK8963_CNTL 0x0A // Power down (0000), single-measurement (0001), self-test (1000) and Fuse ROM (1111) modes on bits 3:0
Suchakhree 0:238df339023b 33 #define AK8963_ASTC 0x0C // Self test control
Suchakhree 0:238df339023b 34 #define AK8963_I2CDIS 0x0F // I2C disable
Suchakhree 0:238df339023b 35 #define AK8963_ASAX 0x10 // Fuse ROM x-axis sensitivity adjustment value
Suchakhree 0:238df339023b 36 #define AK8963_ASAY 0x11 // Fuse ROM y-axis sensitivity adjustment value
Suchakhree 0:238df339023b 37 #define AK8963_ASAZ 0x12 // Fuse ROM z-axis sensitivity adjustment value
Suchakhree 0:238df339023b 38
Suchakhree 0:238df339023b 39 #define SELF_TEST_X_GYRO 0x00
Suchakhree 0:238df339023b 40 #define SELF_TEST_Y_GYRO 0x01
Suchakhree 0:238df339023b 41 #define SELF_TEST_Z_GYRO 0x02
Suchakhree 0:238df339023b 42
Suchakhree 0:238df339023b 43 /*#define X_FINE_GAIN 0x03 // [7:0] fine gain
Suchakhree 0:238df339023b 44 #define Y_FINE_GAIN 0x04
Suchakhree 0:238df339023b 45 #define Z_FINE_GAIN 0x05
Suchakhree 0:238df339023b 46 #define XA_OFFSET_H 0x06 // User-defined trim values for accelerometer
Suchakhree 0:238df339023b 47 #define XA_OFFSET_L_TC 0x07
Suchakhree 0:238df339023b 48 #define YA_OFFSET_H 0x08
Suchakhree 0:238df339023b 49 #define YA_OFFSET_L_TC 0x09
Suchakhree 0:238df339023b 50 #define ZA_OFFSET_H 0x0A
Suchakhree 0:238df339023b 51 #define ZA_OFFSET_L_TC 0x0B */
Suchakhree 0:238df339023b 52
Suchakhree 0:238df339023b 53 #define SELF_TEST_X_ACCEL 0x0D
Suchakhree 0:238df339023b 54 #define SELF_TEST_Y_ACCEL 0x0E
Suchakhree 0:238df339023b 55 #define SELF_TEST_Z_ACCEL 0x0F
Suchakhree 0:238df339023b 56
Suchakhree 0:238df339023b 57 #define SELF_TEST_A 0x10
Suchakhree 0:238df339023b 58
Suchakhree 0:238df339023b 59 #define XG_OFFSET_H 0x13 // User-defined trim values for gyroscope
Suchakhree 0:238df339023b 60 #define XG_OFFSET_L 0x14
Suchakhree 0:238df339023b 61 #define YG_OFFSET_H 0x15
Suchakhree 0:238df339023b 62 #define YG_OFFSET_L 0x16
Suchakhree 0:238df339023b 63 #define ZG_OFFSET_H 0x17
Suchakhree 0:238df339023b 64 #define ZG_OFFSET_L 0x18
Suchakhree 0:238df339023b 65 #define SMPLRT_DIV 0x19
Suchakhree 0:238df339023b 66 #define CONFIG 0x1A
Suchakhree 0:238df339023b 67 #define GYRO_CONFIG 0x1B
Suchakhree 0:238df339023b 68 #define ACCEL_CONFIG 0x1C
Suchakhree 0:238df339023b 69 #define ACCEL_CONFIG2 0x1D
Suchakhree 0:238df339023b 70 #define LP_ACCEL_ODR 0x1E
Suchakhree 0:238df339023b 71 #define WOM_THR 0x1F
Suchakhree 0:238df339023b 72
Suchakhree 0:238df339023b 73 #define MOT_DUR 0x20 // Duration counter threshold for motion interrupt generation, 1 kHz rate, LSB = 1 ms
Suchakhree 0:238df339023b 74 #define ZMOT_THR 0x21 // Zero-motion detection threshold bits [7:0]
Suchakhree 0:238df339023b 75 #define ZRMOT_DUR 0x22 // Duration counter threshold for zero motion interrupt generation, 16 Hz rate, LSB = 64 ms
Suchakhree 0:238df339023b 76
Suchakhree 0:238df339023b 77 #define FIFO_EN 0x23
Suchakhree 0:238df339023b 78 #define I2C_MST_CTRL 0x24
Suchakhree 0:238df339023b 79 #define I2C_SLV0_ADDR 0x25
Suchakhree 0:238df339023b 80 #define I2C_SLV0_REG 0x26
Suchakhree 0:238df339023b 81 #define I2C_SLV0_CTRL 0x27
Suchakhree 0:238df339023b 82 #define I2C_SLV1_ADDR 0x28
Suchakhree 0:238df339023b 83 #define I2C_SLV1_REG 0x29
Suchakhree 0:238df339023b 84 #define I2C_SLV1_CTRL 0x2A
Suchakhree 0:238df339023b 85 #define I2C_SLV2_ADDR 0x2B
Suchakhree 0:238df339023b 86 #define I2C_SLV2_REG 0x2C
Suchakhree 0:238df339023b 87 #define I2C_SLV2_CTRL 0x2D
Suchakhree 0:238df339023b 88 #define I2C_SLV3_ADDR 0x2E
Suchakhree 0:238df339023b 89 #define I2C_SLV3_REG 0x2F
Suchakhree 0:238df339023b 90 #define I2C_SLV3_CTRL 0x30
Suchakhree 0:238df339023b 91 #define I2C_SLV4_ADDR 0x31
Suchakhree 0:238df339023b 92 #define I2C_SLV4_REG 0x32
Suchakhree 0:238df339023b 93 #define I2C_SLV4_DO 0x33
Suchakhree 0:238df339023b 94 #define I2C_SLV4_CTRL 0x34
Suchakhree 0:238df339023b 95 #define I2C_SLV4_DI 0x35
Suchakhree 0:238df339023b 96 #define I2C_MST_STATUS 0x36
Suchakhree 0:238df339023b 97 #define INT_PIN_CFG 0x37
Suchakhree 0:238df339023b 98 #define INT_ENABLE 0x38
Suchakhree 0:238df339023b 99 #define DMP_INT_STATUS 0x39 // Check DMP interrupt
Suchakhree 0:238df339023b 100 #define INT_STATUS 0x3A
Suchakhree 0:238df339023b 101 #define ACCEL_XOUT_H 0x3B
Suchakhree 0:238df339023b 102 #define ACCEL_XOUT_L 0x3C
Suchakhree 0:238df339023b 103 #define ACCEL_YOUT_H 0x3D
Suchakhree 0:238df339023b 104 #define ACCEL_YOUT_L 0x3E
Suchakhree 0:238df339023b 105 #define ACCEL_ZOUT_H 0x3F
Suchakhree 0:238df339023b 106 #define ACCEL_ZOUT_L 0x40
Suchakhree 0:238df339023b 107 #define TEMP_OUT_H 0x41
Suchakhree 0:238df339023b 108 #define TEMP_OUT_L 0x42
Suchakhree 0:238df339023b 109 #define GYRO_XOUT_H 0x43
Suchakhree 0:238df339023b 110 #define GYRO_XOUT_L 0x44
Suchakhree 0:238df339023b 111 #define GYRO_YOUT_H 0x45
Suchakhree 0:238df339023b 112 #define GYRO_YOUT_L 0x46
Suchakhree 0:238df339023b 113 #define GYRO_ZOUT_H 0x47
Suchakhree 0:238df339023b 114 #define GYRO_ZOUT_L 0x48
Suchakhree 0:238df339023b 115 #define EXT_SENS_DATA_00 0x49
Suchakhree 0:238df339023b 116 #define EXT_SENS_DATA_01 0x4A
Suchakhree 0:238df339023b 117 #define EXT_SENS_DATA_02 0x4B
Suchakhree 0:238df339023b 118 #define EXT_SENS_DATA_03 0x4C
Suchakhree 0:238df339023b 119 #define EXT_SENS_DATA_04 0x4D
Suchakhree 0:238df339023b 120 #define EXT_SENS_DATA_05 0x4E
Suchakhree 0:238df339023b 121 #define EXT_SENS_DATA_06 0x4F
Suchakhree 0:238df339023b 122 #define EXT_SENS_DATA_07 0x50
Suchakhree 0:238df339023b 123 #define EXT_SENS_DATA_08 0x51
Suchakhree 0:238df339023b 124 #define EXT_SENS_DATA_09 0x52
Suchakhree 0:238df339023b 125 #define EXT_SENS_DATA_10 0x53
Suchakhree 0:238df339023b 126 #define EXT_SENS_DATA_11 0x54
Suchakhree 0:238df339023b 127 #define EXT_SENS_DATA_12 0x55
Suchakhree 0:238df339023b 128 #define EXT_SENS_DATA_13 0x56
Suchakhree 0:238df339023b 129 #define EXT_SENS_DATA_14 0x57
Suchakhree 0:238df339023b 130 #define EXT_SENS_DATA_15 0x58
Suchakhree 0:238df339023b 131 #define EXT_SENS_DATA_16 0x59
Suchakhree 0:238df339023b 132 #define EXT_SENS_DATA_17 0x5A
Suchakhree 0:238df339023b 133 #define EXT_SENS_DATA_18 0x5B
Suchakhree 0:238df339023b 134 #define EXT_SENS_DATA_19 0x5C
Suchakhree 0:238df339023b 135 #define EXT_SENS_DATA_20 0x5D
Suchakhree 0:238df339023b 136 #define EXT_SENS_DATA_21 0x5E
Suchakhree 0:238df339023b 137 #define EXT_SENS_DATA_22 0x5F
Suchakhree 0:238df339023b 138 #define EXT_SENS_DATA_23 0x60
Suchakhree 0:238df339023b 139 #define MOT_DETECT_STATUS 0x61
Suchakhree 0:238df339023b 140 #define I2C_SLV0_DO 0x63
Suchakhree 0:238df339023b 141 #define I2C_SLV1_DO 0x64
Suchakhree 0:238df339023b 142 #define I2C_SLV2_DO 0x65
Suchakhree 0:238df339023b 143 #define I2C_SLV3_DO 0x66
Suchakhree 0:238df339023b 144 #define I2C_MST_DELAY_CTRL 0x67
Suchakhree 0:238df339023b 145 #define SIGNAL_PATH_RESET 0x68
Suchakhree 0:238df339023b 146 #define MOT_DETECT_CTRL 0x69
Suchakhree 0:238df339023b 147 #define USER_CTRL 0x6A // Bit 7 enable DMP, bit 3 reset DMP
Suchakhree 0:238df339023b 148 #define PWR_MGMT_1 0x6B // Device defaults to the SLEEP mode
Suchakhree 0:238df339023b 149 #define PWR_MGMT_2 0x6C
Suchakhree 0:238df339023b 150 #define DMP_BANK 0x6D // Activates a specific bank in the DMP
Suchakhree 0:238df339023b 151 #define DMP_RW_PNT 0x6E // Set read/write pointer to a specific start address in specified DMP bank
Suchakhree 0:238df339023b 152 #define DMP_REG 0x6F // Register in DMP from which to read or to which to write
Suchakhree 0:238df339023b 153 #define DMP_REG_1 0x70
Suchakhree 0:238df339023b 154 #define DMP_REG_2 0x71
Suchakhree 0:238df339023b 155 #define FIFO_COUNTH 0x72
Suchakhree 0:238df339023b 156 #define FIFO_COUNTL 0x73
Suchakhree 0:238df339023b 157 #define FIFO_R_W 0x74
Suchakhree 0:238df339023b 158 #define WHO_AM_I_MPU9250 0x75 // Should return 0x71
Suchakhree 0:238df339023b 159 #define XA_OFFSET_H 0x77
Suchakhree 0:238df339023b 160 #define XA_OFFSET_L 0x78
Suchakhree 0:238df339023b 161 #define YA_OFFSET_H 0x7A
Suchakhree 0:238df339023b 162 #define YA_OFFSET_L 0x7B
Suchakhree 0:238df339023b 163 #define ZA_OFFSET_H 0x7D
Suchakhree 0:238df339023b 164 #define ZA_OFFSET_L 0x7E
Suchakhree 0:238df339023b 165
Suchakhree 0:238df339023b 166 // Using the MSENSR-9250 breakout board, ADO is set to 0
Suchakhree 0:238df339023b 167 // Seven-bit device address is 110100 for ADO = 0 and 110101 for ADO = 1
Suchakhree 0:238df339023b 168 //mbed uses the eight-bit device address, so shift seven-bit addresses left by one!
Suchakhree 0:238df339023b 169 #define ADO 0
Suchakhree 0:238df339023b 170 #if ADO
Suchakhree 0:238df339023b 171 #define MPU9250_ADDRESS 0x69<<1 // Device address when ADO = 1
Suchakhree 0:238df339023b 172 #else
Suchakhree 0:238df339023b 173 #define MPU9250_ADDRESS 0x68<<1 // Device address when ADO = 0
Suchakhree 0:238df339023b 174 #endif
Suchakhree 0:238df339023b 175
Suchakhree 0:238df339023b 176 // Set initial input parameters
Suchakhree 0:238df339023b 177 enum Ascale {
Suchakhree 0:238df339023b 178 AFS_2G = 0,
Suchakhree 0:238df339023b 179 AFS_4G,
Suchakhree 0:238df339023b 180 AFS_8G,
Suchakhree 0:238df339023b 181 AFS_16G
Suchakhree 0:238df339023b 182 };
Suchakhree 0:238df339023b 183
Suchakhree 0:238df339023b 184 enum Gscale {
Suchakhree 0:238df339023b 185 GFS_250DPS = 0,
Suchakhree 0:238df339023b 186 GFS_500DPS,
Suchakhree 0:238df339023b 187 GFS_1000DPS,
Suchakhree 0:238df339023b 188 GFS_2000DPS
Suchakhree 0:238df339023b 189 };
Suchakhree 0:238df339023b 190
Suchakhree 0:238df339023b 191 enum Mscale {
Suchakhree 0:238df339023b 192 MFS_14BITS = 0, // 0.6 mG per LSB
Suchakhree 0:238df339023b 193 MFS_16BITS // 0.15 mG per LSB
Suchakhree 0:238df339023b 194 };
Suchakhree 0:238df339023b 195
Suchakhree 0:238df339023b 196 uint8_t Ascale = AFS_2G; // AFS_2G, AFS_4G, AFS_8G, AFS_16G
Suchakhree 0:238df339023b 197 uint8_t Gscale = GFS_250DPS; // GFS_250DPS, GFS_500DPS, GFS_1000DPS, GFS_2000DPS
Suchakhree 0:238df339023b 198 uint8_t Mscale = MFS_16BITS; // MFS_14BITS or MFS_16BITS, 14-bit or 16-bit magnetometer resolution
Suchakhree 0:238df339023b 199 uint8_t Mmode = 0x06; // Either 8 Hz 0x02) or 100 Hz (0x06) magnetometer data ODR
Suchakhree 0:238df339023b 200 float aRes, gRes, mRes; // scale resolutions per LSB for the sensors
Suchakhree 0:238df339023b 201 int I2Cstate=1; // If I2Cstate!=0, I2C read or write operation has failed
Suchakhree 0:238df339023b 202
Suchakhree 0:238df339023b 203 //Set up I2C, (SDA,SCL)
Suchakhree 0:238df339023b 204 I2C i2c(I2C_SDA, I2C_SCL);
Suchakhree 0:238df339023b 205
Suchakhree 0:238df339023b 206 DigitalOut myled(LED1);
Suchakhree 0:238df339023b 207
Suchakhree 0:238df339023b 208 // Pin definitions
Suchakhree 0:238df339023b 209 int intPin = 12; // These can be changed, 2 and 3 are the Arduinos ext int pins
Suchakhree 0:238df339023b 210
Suchakhree 0:238df339023b 211 int16_t accelCount[3]; // Stores the 16-bit signed accelerometer sensor output
Suchakhree 0:238df339023b 212 int16_t gyroCount[3]; // Stores the 16-bit signed gyro sensor output
Suchakhree 0:238df339023b 213 int16_t magCount[3]; // Stores the 16-bit signed magnetometer sensor output
Suchakhree 0:238df339023b 214 float magCalibration[3] = {0, 0, 0}, magbias[3] = {0, 0, 0}; // Factory mag calibration and mag bias
Suchakhree 0:238df339023b 215 float gyroBias[3] = {0, 0, 0}, accelBias[3] = {0, 0, 0}; // Bias corrections for gyro and accelerometer
Suchakhree 0:238df339023b 216 float ax, ay, az, gx, gy, gz, mx, my, mz; // variables to hold latest sensor data values
Suchakhree 0:238df339023b 217 int16_t tempCount; // Stores the real internal chip temperature in degrees Celsius
Suchakhree 0:238df339023b 218 float temperature;
Suchakhree 0:238df339023b 219 float SelfTest[6];
Suchakhree 0:238df339023b 220 float orientation[1];
Suchakhree 0:238df339023b 221 float magn_x, magn_y;
Suchakhree 0:238df339023b 222
Suchakhree 0:238df339023b 223 int delt_t = 0; // used to control display output rate
Suchakhree 0:238df339023b 224 int count = 0; // used to control display output rate
Suchakhree 0:238df339023b 225
Suchakhree 0:238df339023b 226 // parameters for 6 DoF sensor fusion calculations
Suchakhree 0:238df339023b 227 float PI = 3.14159265358979323846f;
Suchakhree 0:238df339023b 228 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
Suchakhree 0:238df339023b 229 float beta = sqrt(3.0f / 4.0f) * GyroMeasError; // compute beta
Suchakhree 0:238df339023b 230 float GyroMeasDrift = PI * (1.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
Suchakhree 0:238df339023b 231 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
Suchakhree 0:238df339023b 232 #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
Suchakhree 0:238df339023b 233 #define Ki 0.0f
Suchakhree 0:238df339023b 234
Suchakhree 0:238df339023b 235 float pitch, yaw, roll;
Suchakhree 0:238df339023b 236 float deltat = 0.0f; // integration interval for both filter schemes
Suchakhree 0:238df339023b 237 int lastUpdate = 0, firstUpdate = 0, Now = 0; // used to calculate integration interval // used to calculate integration interval
Suchakhree 0:238df339023b 238 float q[4] = {1.0f, 0.0f, 0.0f, 0.0f}; // vector to hold quaternion
Suchakhree 0:238df339023b 239 float eInt[3] = {0.0f, 0.0f, 0.0f}; // vector to hold integral error for Mahony method
Suchakhree 0:238df339023b 240
Suchakhree 0:238df339023b 241 class MPU9250 {
Suchakhree 0:238df339023b 242
Suchakhree 0:238df339023b 243 protected:
Suchakhree 0:238df339023b 244
Suchakhree 0:238df339023b 245 public:
Suchakhree 0:238df339023b 246 //===================================================================================================================
Suchakhree 0:238df339023b 247 //====== Set of useful function to access acceleration, gyroscope, and temperature data
Suchakhree 0:238df339023b 248 //===================================================================================================================
Suchakhree 0:238df339023b 249
Suchakhree 0:238df339023b 250 void writeByte(uint8_t address, uint8_t subAddress, uint8_t data)
Suchakhree 0:238df339023b 251 {
Suchakhree 0:238df339023b 252 char data_write[2];
Suchakhree 0:238df339023b 253 data_write[0] = subAddress;
Suchakhree 0:238df339023b 254 data_write[1] = data;
Suchakhree 0:238df339023b 255 I2Cstate = i2c.write(address, data_write, 2, 0);
Suchakhree 0:238df339023b 256 }
Suchakhree 0:238df339023b 257
Suchakhree 0:238df339023b 258 char readByte(uint8_t address, uint8_t subAddress)
Suchakhree 0:238df339023b 259 {
Suchakhree 0:238df339023b 260 char data[1]; // `data` will store the register data
Suchakhree 0:238df339023b 261 char data_write[1];
Suchakhree 0:238df339023b 262 data_write[0] = subAddress;
Suchakhree 0:238df339023b 263 I2Cstate = i2c.write(address, data_write, 1, 1); // no stop
Suchakhree 0:238df339023b 264 I2Cstate = i2c.read(address, data, 1, 0);
Suchakhree 0:238df339023b 265 return data[0];
Suchakhree 0:238df339023b 266 }
Suchakhree 0:238df339023b 267
Suchakhree 0:238df339023b 268 void readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest) // count=nº of bytes to read / dest=destiny where data is stored
Suchakhree 0:238df339023b 269 {
Suchakhree 0:238df339023b 270 char data[14];
Suchakhree 0:238df339023b 271 char data_write[1];
Suchakhree 0:238df339023b 272 data_write[0] = subAddress;
Suchakhree 0:238df339023b 273 I2Cstate = i2c.write(address, data_write, 1, 1); // no stop
Suchakhree 0:238df339023b 274 I2Cstate = i2c.read(address, data, count, 0);
Suchakhree 0:238df339023b 275 for(int ii = 0; ii < count; ii++) {
Suchakhree 0:238df339023b 276 dest[ii] = data[ii];
Suchakhree 0:238df339023b 277 }
Suchakhree 0:238df339023b 278 }
Suchakhree 0:238df339023b 279
Suchakhree 0:238df339023b 280 void getMres() {
Suchakhree 0:238df339023b 281 switch (Mscale)
Suchakhree 0:238df339023b 282 {
Suchakhree 0:238df339023b 283 // Possible magnetometer scales (and their register bit settings) are:
Suchakhree 0:238df339023b 284 // 14 bit resolution (0) and 16 bit resolution (1)
Suchakhree 0:238df339023b 285 case MFS_14BITS:
Suchakhree 0:238df339023b 286 mRes = 10.0*4219.0/8190.0; // Proper scale to return milliGauss
Suchakhree 0:238df339023b 287 break;
Suchakhree 0:238df339023b 288 case MFS_16BITS:
Suchakhree 0:238df339023b 289 mRes = 10.0*4219.0/32760.0; // Proper scale to return milliGauss
Suchakhree 0:238df339023b 290 break;
Suchakhree 0:238df339023b 291 }
Suchakhree 0:238df339023b 292 }
Suchakhree 0:238df339023b 293
Suchakhree 0:238df339023b 294 void getGres() {
Suchakhree 0:238df339023b 295 switch (Gscale)
Suchakhree 0:238df339023b 296 {
Suchakhree 0:238df339023b 297 // Possible gyro scales (and their register bit settings) are:
Suchakhree 0:238df339023b 298 // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS (11).
Suchakhree 0:238df339023b 299 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
Suchakhree 0:238df339023b 300 case GFS_250DPS:
Suchakhree 0:238df339023b 301 gRes = 250.0/32768.0;
Suchakhree 0:238df339023b 302 break;
Suchakhree 0:238df339023b 303 case GFS_500DPS:
Suchakhree 0:238df339023b 304 gRes = 500.0/32768.0;
Suchakhree 0:238df339023b 305 break;
Suchakhree 0:238df339023b 306 case GFS_1000DPS:
Suchakhree 0:238df339023b 307 gRes = 1000.0/32768.0;
Suchakhree 0:238df339023b 308 break;
Suchakhree 0:238df339023b 309 case GFS_2000DPS:
Suchakhree 0:238df339023b 310 gRes = 2000.0/32768.0;
Suchakhree 0:238df339023b 311 break;
Suchakhree 0:238df339023b 312 }
Suchakhree 0:238df339023b 313 }
Suchakhree 0:238df339023b 314
Suchakhree 0:238df339023b 315 void getAres() {
Suchakhree 0:238df339023b 316 switch (Ascale)
Suchakhree 0:238df339023b 317 {
Suchakhree 0:238df339023b 318 // Possible accelerometer scales (and their register bit settings) are:
Suchakhree 0:238df339023b 319 // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs (11).
Suchakhree 0:238df339023b 320 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
Suchakhree 0:238df339023b 321 case AFS_2G:
Suchakhree 0:238df339023b 322 aRes = 2.0/32768.0;
Suchakhree 0:238df339023b 323 break;
Suchakhree 0:238df339023b 324 case AFS_4G:
Suchakhree 0:238df339023b 325 aRes = 4.0/32768.0;
Suchakhree 0:238df339023b 326 break;
Suchakhree 0:238df339023b 327 case AFS_8G:
Suchakhree 0:238df339023b 328 aRes = 8.0/32768.0;
Suchakhree 0:238df339023b 329 break;
Suchakhree 0:238df339023b 330 case AFS_16G:
Suchakhree 0:238df339023b 331 aRes = 16.0/32768.0;
Suchakhree 0:238df339023b 332 break;
Suchakhree 0:238df339023b 333 }
Suchakhree 0:238df339023b 334 }
Suchakhree 0:238df339023b 335
Suchakhree 0:238df339023b 336 void readAccelData(int16_t * destination){
Suchakhree 0:238df339023b 337
Suchakhree 0:238df339023b 338 uint8_t rawData[6]; // x/y/z accel register data stored here
Suchakhree 0:238df339023b 339 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
Suchakhree 0:238df339023b 340 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
Suchakhree 0:238df339023b 341 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
Suchakhree 0:238df339023b 342 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
Suchakhree 0:238df339023b 343 }
Suchakhree 0:238df339023b 344
Suchakhree 0:238df339023b 345 void readGyroData(int16_t * destination){
Suchakhree 0:238df339023b 346 uint8_t rawData[6]; // x/y/z gyro register data stored here
Suchakhree 0:238df339023b 347 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
Suchakhree 0:238df339023b 348 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
Suchakhree 0:238df339023b 349 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
Suchakhree 0:238df339023b 350 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
Suchakhree 0:238df339023b 351 }
Suchakhree 0:238df339023b 352
Suchakhree 0:238df339023b 353 void readMagData(int16_t * destination){
Suchakhree 0:238df339023b 354 uint8_t rawData[7]; // x/y/z gyro register data, ST2 register stored here, must read ST2 at end of data acquisition
Suchakhree 0:238df339023b 355 if(readByte(AK8963_ADDRESS, AK8963_ST1) & 0x01) { // wait for magnetometer data ready bit to be set
Suchakhree 0:238df339023b 356 readBytes(AK8963_ADDRESS, AK8963_XOUT_L, 7, &rawData[0]); // Read the six raw data and ST2 registers sequentially into data array
Suchakhree 0:238df339023b 357 uint8_t c = rawData[6]; // End data read by reading ST2 register
Suchakhree 0:238df339023b 358 if(!(c & 0x08)) { // Check if magnetic sensor overflow set, if not then report data
Suchakhree 0:238df339023b 359 destination[0] = (int16_t)(((int16_t)rawData[1] << 8) | rawData[0]); // Turn the MSB and LSB into a signed 16-bit value
Suchakhree 0:238df339023b 360 destination[1] = (int16_t)(((int16_t)rawData[3] << 8) | rawData[2]) ; // Data stored as little Endian
Suchakhree 0:238df339023b 361 destination[2] = (int16_t)(((int16_t)rawData[5] << 8) | rawData[4]) ;
Suchakhree 0:238df339023b 362 }
Suchakhree 0:238df339023b 363 }
Suchakhree 0:238df339023b 364 }
Suchakhree 0:238df339023b 365
Suchakhree 0:238df339023b 366 int16_t readTempData(){
Suchakhree 0:238df339023b 367 uint8_t rawData[2]; // x/y/z gyro register data stored here
Suchakhree 0:238df339023b 368 readBytes(MPU9250_ADDRESS, TEMP_OUT_H, 2, &rawData[0]); // Read the two raw data registers sequentially into data array
Suchakhree 0:238df339023b 369 return (int16_t)(((int16_t)rawData[0]) << 8 | rawData[1]) ; // Turn the MSB and LSB into a 16-bit value
Suchakhree 0:238df339023b 370 }
Suchakhree 0:238df339023b 371
Suchakhree 0:238df339023b 372 void resetMPU9250(){
Suchakhree 0:238df339023b 373 // reset device
Suchakhree 0:238df339023b 374 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
Suchakhree 0:238df339023b 375 wait(0.1);
Suchakhree 0:238df339023b 376 }
Suchakhree 0:238df339023b 377
Suchakhree 0:238df339023b 378 void initAK8963(float * destination){
Suchakhree 0:238df339023b 379 // First extract the factory calibration for each magnetometer axis
Suchakhree 0:238df339023b 380 uint8_t rawData[3]; // x/y/z gyro calibration data stored here
Suchakhree 0:238df339023b 381 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
Suchakhree 0:238df339023b 382 wait(0.01);
Suchakhree 0:238df339023b 383 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x0F); // Enter Fuse ROM access mode
Suchakhree 0:238df339023b 384 wait(0.01);
Suchakhree 0:238df339023b 385 readBytes(AK8963_ADDRESS, AK8963_ASAX, 3, &rawData[0]); // Read the x-, y-, and z-axis calibration values
Suchakhree 0:238df339023b 386 destination[0] = (float)(rawData[0] - 128)/256.0f + 1.0f; // Return x-axis sensitivity adjustment values, etc.
Suchakhree 0:238df339023b 387 destination[1] = (float)(rawData[1] - 128)/256.0f + 1.0f;
Suchakhree 0:238df339023b 388 destination[2] = (float)(rawData[2] - 128)/256.0f + 1.0f;
Suchakhree 0:238df339023b 389 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
Suchakhree 0:238df339023b 390 wait(0.01);
Suchakhree 0:238df339023b 391 // Configure the magnetometer for continuous read and highest resolution
Suchakhree 0:238df339023b 392 // set Mscale bit 4 to 1 (0) to enable 16 (14) bit resolution in CNTL register,
Suchakhree 0:238df339023b 393 // and enable continuous mode data acquisition Mmode (bits [3:0]), 0010 for 8 Hz and 0110 for 100 Hz sample rates
Suchakhree 0:238df339023b 394 writeByte(AK8963_ADDRESS, AK8963_CNTL, Mscale << 4 | Mmode); // Set magnetometer data resolution and sample ODR
Suchakhree 0:238df339023b 395 wait(0.01);
Suchakhree 0:238df339023b 396 }
Suchakhree 0:238df339023b 397
Suchakhree 0:238df339023b 398 void initMPU9250(){
Suchakhree 0:238df339023b 399 // Initialize MPU9250 device
Suchakhree 0:238df339023b 400 // wake up device
Suchakhree 0:238df339023b 401 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors
Suchakhree 0:238df339023b 402 wait(0.1); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt
Suchakhree 0:238df339023b 403
Suchakhree 0:238df339023b 404 // get stable time source
Suchakhree 0:238df339023b 405 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01); // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
Suchakhree 0:238df339023b 406
Suchakhree 0:238df339023b 407 // Configure Gyro and Accelerometer
Suchakhree 0:238df339023b 408 // Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively;
Suchakhree 0:238df339023b 409 // DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both
Suchakhree 0:238df339023b 410 // Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate
Suchakhree 0:238df339023b 411 writeByte(MPU9250_ADDRESS, CONFIG, 0x03);
Suchakhree 0:238df339023b 412
Suchakhree 0:238df339023b 413 // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV)
Suchakhree 0:238df339023b 414 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x04); // Use a 200 Hz rate; the same rate set in CONFIG above
Suchakhree 0:238df339023b 415
Suchakhree 0:238df339023b 416 // Set gyroscope full scale range
Suchakhree 0:238df339023b 417 // Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3
Suchakhree 0:238df339023b 418 uint8_t c = readByte(MPU9250_ADDRESS, GYRO_CONFIG);
Suchakhree 0:238df339023b 419 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
Suchakhree 0:238df339023b 420 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
Suchakhree 0:238df339023b 421 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c | Gscale << 3); // Set full scale range for the gyro
Suchakhree 0:238df339023b 422
Suchakhree 0:238df339023b 423 // Set accelerometer configuration
Suchakhree 0:238df339023b 424 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG);
Suchakhree 0:238df339023b 425 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
Suchakhree 0:238df339023b 426 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
Suchakhree 0:238df339023b 427 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c | Ascale << 3); // Set full scale range for the accelerometer
Suchakhree 0:238df339023b 428
Suchakhree 0:238df339023b 429 // Set accelerometer sample rate configuration
Suchakhree 0:238df339023b 430 // It is possible to get a 4 kHz sample rate from the accelerometer by choosing 1 for
Suchakhree 0:238df339023b 431 // accel_fchoice_b bit [3]; in this case the bandwidth is 1.13 kHz
Suchakhree 0:238df339023b 432 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG2);
Suchakhree 0:238df339023b 433 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c & ~0x0F); // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0])
Suchakhree 0:238df339023b 434 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c | 0x03); // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz
Suchakhree 0:238df339023b 435
Suchakhree 0:238df339023b 436 // The accelerometer, gyro, and thermometer are set to 1 kHz sample rates,
Suchakhree 0:238df339023b 437 // but all these rates are further reduced by a factor of 5 to 200 Hz because of the SMPLRT_DIV setting
Suchakhree 0:238df339023b 438
Suchakhree 0:238df339023b 439 // Configure Interrupts and Bypass Enable
Suchakhree 0:238df339023b 440 // Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips
Suchakhree 0:238df339023b 441 // can join the I2C bus and all can be controlled by the Arduino as master
Suchakhree 0:238df339023b 442 writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x22);
Suchakhree 0:238df339023b 443 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt
Suchakhree 0:238df339023b 444 }
Suchakhree 0:238df339023b 445
Suchakhree 0:238df339023b 446 // Function which accumulates gyro and accelerometer data after device initialization. It calculates the average
Suchakhree 0:238df339023b 447 // of the at-rest readings and then loads the resulting offsets into accelerometer and gyro bias registers.
Suchakhree 0:238df339023b 448 void calibrateMPU9250(float * dest1, float * dest2)
Suchakhree 0:238df339023b 449 {
Suchakhree 0:238df339023b 450 uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data
Suchakhree 0:238df339023b 451 uint16_t ii, packet_count, fifo_count;
Suchakhree 0:238df339023b 452 int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
Suchakhree 0:238df339023b 453
Suchakhree 0:238df339023b 454 // reset device, reset all registers, clear gyro and accelerometer bias registers
Suchakhree 0:238df339023b 455 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
Suchakhree 0:238df339023b 456 wait(0.1);
Suchakhree 0:238df339023b 457
Suchakhree 0:238df339023b 458 // get stable time source
Suchakhree 0:238df339023b 459 // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
Suchakhree 0:238df339023b 460 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01);
Suchakhree 0:238df339023b 461 writeByte(MPU9250_ADDRESS, PWR_MGMT_2, 0x00);
Suchakhree 0:238df339023b 462 wait(0.2);
Suchakhree 0:238df339023b 463
Suchakhree 0:238df339023b 464 // Configure device for bias calculation
Suchakhree 0:238df339023b 465 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts
Suchakhree 0:238df339023b 466 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable FIFO
Suchakhree 0:238df339023b 467 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source
Suchakhree 0:238df339023b 468 writeByte(MPU9250_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master
Suchakhree 0:238df339023b 469 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes
Suchakhree 0:238df339023b 470 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP
Suchakhree 0:238df339023b 471 wait(0.015);
Suchakhree 0:238df339023b 472
Suchakhree 0:238df339023b 473 // Configure MPU9250 gyro and accelerometer for bias calculation
Suchakhree 0:238df339023b 474 writeByte(MPU9250_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz
Suchakhree 0:238df339023b 475 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz
Suchakhree 0:238df339023b 476 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity
Suchakhree 0:238df339023b 477 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity
Suchakhree 0:238df339023b 478
Suchakhree 0:238df339023b 479 uint16_t gyrosensitivity = 131; // = 131 LSB/degrees/sec
Suchakhree 0:238df339023b 480 uint16_t accelsensitivity = 16384; // = 16384 LSB/g
Suchakhree 0:238df339023b 481
Suchakhree 0:238df339023b 482 // Configure FIFO to capture accelerometer and gyro data. This data will be used for bias calculation
Suchakhree 0:238df339023b 483 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x40); // Enable FIFO
Suchakhree 0:238df339023b 484 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9250)
Suchakhree 0:238df339023b 485 wait(0.04); // accumulate 40 samples in 80 milliseconds = 480 bytes
Suchakhree 0:238df339023b 486
Suchakhree 0:238df339023b 487 // At end of sample accumulation, turn off FIFO sensor read
Suchakhree 0:238df339023b 488 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO
Suchakhree 0:238df339023b 489 readBytes(MPU9250_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count
Suchakhree 0:238df339023b 490 fifo_count = ((uint16_t)data[0] << 8) | data[1];
Suchakhree 0:238df339023b 491 packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging
Suchakhree 0:238df339023b 492
Suchakhree 0:238df339023b 493 for (ii = 0; ii < packet_count; ii++) {
Suchakhree 0:238df339023b 494 int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0};
Suchakhree 0:238df339023b 495 readBytes(MPU9250_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging
Suchakhree 0:238df339023b 496 accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO
Suchakhree 0:238df339023b 497 accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ;
Suchakhree 0:238df339023b 498 accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ;
Suchakhree 0:238df339023b 499 gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ;
Suchakhree 0:238df339023b 500 gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ;
Suchakhree 0:238df339023b 501 gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ;
Suchakhree 0:238df339023b 502
Suchakhree 0:238df339023b 503 accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases
Suchakhree 0:238df339023b 504 accel_bias[1] += (int32_t) accel_temp[1];
Suchakhree 0:238df339023b 505 accel_bias[2] += (int32_t) accel_temp[2];
Suchakhree 0:238df339023b 506 gyro_bias[0] += (int32_t) gyro_temp[0];
Suchakhree 0:238df339023b 507 gyro_bias[1] += (int32_t) gyro_temp[1];
Suchakhree 0:238df339023b 508 gyro_bias[2] += (int32_t) gyro_temp[2];
Suchakhree 0:238df339023b 509
Suchakhree 0:238df339023b 510 }
Suchakhree 0:238df339023b 511 accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases
Suchakhree 0:238df339023b 512 accel_bias[1] /= (int32_t) packet_count;
Suchakhree 0:238df339023b 513 accel_bias[2] /= (int32_t) packet_count;
Suchakhree 0:238df339023b 514 gyro_bias[0] /= (int32_t) packet_count;
Suchakhree 0:238df339023b 515 gyro_bias[1] /= (int32_t) packet_count;
Suchakhree 0:238df339023b 516 gyro_bias[2] /= (int32_t) packet_count;
Suchakhree 0:238df339023b 517
Suchakhree 0:238df339023b 518 if(accel_bias[2] > 0L) {accel_bias[2] -= (int32_t) accelsensitivity;} // Remove gravity from the z-axis accelerometer bias calculation
Suchakhree 0:238df339023b 519 else {accel_bias[2] += (int32_t) accelsensitivity;}
Suchakhree 0:238df339023b 520
Suchakhree 0:238df339023b 521 // Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup
Suchakhree 0:238df339023b 522 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
Suchakhree 0:238df339023b 523 data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
Suchakhree 0:238df339023b 524 data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF;
Suchakhree 0:238df339023b 525 data[3] = (-gyro_bias[1]/4) & 0xFF;
Suchakhree 0:238df339023b 526 data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF;
Suchakhree 0:238df339023b 527 data[5] = (-gyro_bias[2]/4) & 0xFF;
Suchakhree 0:238df339023b 528
Suchakhree 0:238df339023b 529 /// Push gyro biases to hardware registers
Suchakhree 0:238df339023b 530 /* writeByte(MPU9250_ADDRESS, XG_OFFSET_H, data[0]);
Suchakhree 0:238df339023b 531 writeByte(MPU9250_ADDRESS, XG_OFFSET_L, data[1]);
Suchakhree 0:238df339023b 532 writeByte(MPU9250_ADDRESS, YG_OFFSET_H, data[2]);
Suchakhree 0:238df339023b 533 writeByte(MPU9250_ADDRESS, YG_OFFSET_L, data[3]);
Suchakhree 0:238df339023b 534 writeByte(MPU9250_ADDRESS, ZG_OFFSET_H, data[4]);
Suchakhree 0:238df339023b 535 writeByte(MPU9250_ADDRESS, ZG_OFFSET_L, data[5]);
Suchakhree 0:238df339023b 536 */
Suchakhree 0:238df339023b 537 dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction
Suchakhree 0:238df339023b 538 dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity;
Suchakhree 0:238df339023b 539 dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity;
Suchakhree 0:238df339023b 540
Suchakhree 0:238df339023b 541 // Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain
Suchakhree 0:238df339023b 542 // factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold
Suchakhree 0:238df339023b 543 // non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature
Suchakhree 0:238df339023b 544 // compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that
Suchakhree 0:238df339023b 545 // the accelerometer biases calculated above must be divided by 8.
Suchakhree 0:238df339023b 546
Suchakhree 0:238df339023b 547 int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases
Suchakhree 0:238df339023b 548 readBytes(MPU9250_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values
Suchakhree 0:238df339023b 549 accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1];
Suchakhree 0:238df339023b 550 readBytes(MPU9250_ADDRESS, YA_OFFSET_H, 2, &data[0]);
Suchakhree 0:238df339023b 551 accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1];
Suchakhree 0:238df339023b 552 readBytes(MPU9250_ADDRESS, ZA_OFFSET_H, 2, &data[0]);
Suchakhree 0:238df339023b 553 accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1];
Suchakhree 0:238df339023b 554
Suchakhree 0:238df339023b 555 uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers
Suchakhree 0:238df339023b 556 uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis
Suchakhree 0:238df339023b 557
Suchakhree 0:238df339023b 558 for(ii = 0; ii < 3; ii++) {
Suchakhree 0:238df339023b 559 if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit
Suchakhree 0:238df339023b 560 }
Suchakhree 0:238df339023b 561
Suchakhree 0:238df339023b 562 // Construct total accelerometer bias, including calculated average accelerometer bias from above
Suchakhree 0:238df339023b 563 accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale)
Suchakhree 0:238df339023b 564 accel_bias_reg[1] -= (accel_bias[1]/8);
Suchakhree 0:238df339023b 565 accel_bias_reg[2] -= (accel_bias[2]/8);
Suchakhree 0:238df339023b 566
Suchakhree 0:238df339023b 567 data[0] = (accel_bias_reg[0] >> 8) & 0xFF;
Suchakhree 0:238df339023b 568 data[1] = (accel_bias_reg[0]) & 0xFF;
Suchakhree 0:238df339023b 569 data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers
Suchakhree 0:238df339023b 570 data[2] = (accel_bias_reg[1] >> 8) & 0xFF;
Suchakhree 0:238df339023b 571 data[3] = (accel_bias_reg[1]) & 0xFF;
Suchakhree 0:238df339023b 572 data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers
Suchakhree 0:238df339023b 573 data[4] = (accel_bias_reg[2] >> 8) & 0xFF;
Suchakhree 0:238df339023b 574 data[5] = (accel_bias_reg[2]) & 0xFF;
Suchakhree 0:238df339023b 575 data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers
Suchakhree 0:238df339023b 576
Suchakhree 0:238df339023b 577 // Apparently this is not working for the acceleration biases in the MPU-9250
Suchakhree 0:238df339023b 578 // Are we handling the temperature correction bit properly?
Suchakhree 0:238df339023b 579 // Push accelerometer biases to hardware registers
Suchakhree 0:238df339023b 580 /* writeByte(MPU9250_ADDRESS, XA_OFFSET_H, data[0]);
Suchakhree 0:238df339023b 581 writeByte(MPU9250_ADDRESS, XA_OFFSET_L, data[1]);
Suchakhree 0:238df339023b 582 writeByte(MPU9250_ADDRESS, YA_OFFSET_H, data[2]);
Suchakhree 0:238df339023b 583 writeByte(MPU9250_ADDRESS, YA_OFFSET_L, data[3]);
Suchakhree 0:238df339023b 584 writeByte(MPU9250_ADDRESS, ZA_OFFSET_H, data[4]);
Suchakhree 0:238df339023b 585 writeByte(MPU9250_ADDRESS, ZA_OFFSET_L, data[5]);
Suchakhree 0:238df339023b 586 */
Suchakhree 0:238df339023b 587 // Output scaled accelerometer biases for manual subtraction in the main program
Suchakhree 0:238df339023b 588 dest2[0] = (float)accel_bias[0]/(float)accelsensitivity;
Suchakhree 0:238df339023b 589 dest2[1] = (float)accel_bias[1]/(float)accelsensitivity;
Suchakhree 0:238df339023b 590 dest2[2] = (float)accel_bias[2]/(float)accelsensitivity;
Suchakhree 0:238df339023b 591 }
Suchakhree 0:238df339023b 592
Suchakhree 0:238df339023b 593
Suchakhree 0:238df339023b 594 // Accelerometer and gyroscope self test; check calibration wrt factory settings
Suchakhree 0:238df339023b 595 void MPU9250SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass
Suchakhree 0:238df339023b 596 {
Suchakhree 0:238df339023b 597 uint8_t rawData[6] = {0, 0, 0, 0, 0, 0};
Suchakhree 0:238df339023b 598 uint8_t selfTest[6];
Suchakhree 0:238df339023b 599 int16_t gAvg[3], aAvg[3], aSTAvg[3], gSTAvg[3];
Suchakhree 0:238df339023b 600 float factoryTrim[6];
Suchakhree 0:238df339023b 601 uint8_t FS = 0;
Suchakhree 0:238df339023b 602
Suchakhree 0:238df339023b 603 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz
Suchakhree 0:238df339023b 604 writeByte(MPU9250_ADDRESS, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz
Suchakhree 0:238df339023b 605 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 1<<FS); // Set full scale range for the gyro to 250 dps
Suchakhree 0:238df339023b 606 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz
Suchakhree 0:238df339023b 607 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 1<<FS); // Set full scale range for the accelerometer to 2 g
Suchakhree 0:238df339023b 608
Suchakhree 0:238df339023b 609 for( int ii = 0; ii < 200; ii++) { // get average current values of gyro and acclerometer
Suchakhree 0:238df339023b 610
Suchakhree 0:238df339023b 611 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
Suchakhree 0:238df339023b 612 aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
Suchakhree 0:238df339023b 613 aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
Suchakhree 0:238df339023b 614 aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
Suchakhree 0:238df339023b 615
Suchakhree 0:238df339023b 616 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
Suchakhree 0:238df339023b 617 gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
Suchakhree 0:238df339023b 618 gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
Suchakhree 0:238df339023b 619 gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
Suchakhree 0:238df339023b 620 }
Suchakhree 0:238df339023b 621
Suchakhree 0:238df339023b 622 for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average current readings
Suchakhree 0:238df339023b 623 aAvg[ii] /= 200;
Suchakhree 0:238df339023b 624 gAvg[ii] /= 200;
Suchakhree 0:238df339023b 625 }
Suchakhree 0:238df339023b 626
Suchakhree 0:238df339023b 627 // Configure the accelerometer for self-test
Suchakhree 0:238df339023b 628 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g
Suchakhree 0:238df339023b 629 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
Suchakhree 0:238df339023b 630 wait_ms(25); // Delay a while to let the device stabilize
Suchakhree 0:238df339023b 631
Suchakhree 0:238df339023b 632 for( int ii = 0; ii < 200; ii++) { // get average self-test values of gyro and acclerometer
Suchakhree 0:238df339023b 633
Suchakhree 0:238df339023b 634 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
Suchakhree 0:238df339023b 635 aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
Suchakhree 0:238df339023b 636 aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
Suchakhree 0:238df339023b 637 aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
Suchakhree 0:238df339023b 638
Suchakhree 0:238df339023b 639 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
Suchakhree 0:238df339023b 640 gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
Suchakhree 0:238df339023b 641 gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
Suchakhree 0:238df339023b 642 gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
Suchakhree 0:238df339023b 643 }
Suchakhree 0:238df339023b 644
Suchakhree 0:238df339023b 645 for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average self-test readings
Suchakhree 0:238df339023b 646 aSTAvg[ii] /= 200;
Suchakhree 0:238df339023b 647 gSTAvg[ii] /= 200;
Suchakhree 0:238df339023b 648 }
Suchakhree 0:238df339023b 649
Suchakhree 0:238df339023b 650 // Configure the gyro and accelerometer for normal operation
Suchakhree 0:238df339023b 651 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00);
Suchakhree 0:238df339023b 652 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00);
Suchakhree 0:238df339023b 653 //delay(25); // Delay a while to let the device stabilize
Suchakhree 0:238df339023b 654 wait_ms(25); // Delay a while to let the device stabilize
Suchakhree 0:238df339023b 655
Suchakhree 0:238df339023b 656 // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg
Suchakhree 0:238df339023b 657 selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results
Suchakhree 0:238df339023b 658 selfTest[1] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_ACCEL); // Y-axis accel self-test results
Suchakhree 0:238df339023b 659 selfTest[2] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_ACCEL); // Z-axis accel self-test results
Suchakhree 0:238df339023b 660 selfTest[3] = readByte(MPU9250_ADDRESS, SELF_TEST_X_GYRO); // X-axis gyro self-test results
Suchakhree 0:238df339023b 661 selfTest[4] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_GYRO); // Y-axis gyro self-test results
Suchakhree 0:238df339023b 662 selfTest[5] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_GYRO); // Z-axis gyro self-test results
Suchakhree 0:238df339023b 663
Suchakhree 0:238df339023b 664 // Retrieve factory self-test value from self-test code reads
Suchakhree 0:238df339023b 665 factoryTrim[0] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation
Suchakhree 0:238df339023b 666 factoryTrim[1] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation
Suchakhree 0:238df339023b 667 factoryTrim[2] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation
Suchakhree 0:238df339023b 668 factoryTrim[3] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation
Suchakhree 0:238df339023b 669 factoryTrim[4] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation
Suchakhree 0:238df339023b 670 factoryTrim[5] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation
Suchakhree 0:238df339023b 671
Suchakhree 0:238df339023b 672 // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response
Suchakhree 0:238df339023b 673 // To get percent, must multiply by 100
Suchakhree 0:238df339023b 674 for (int i = 0; i < 3; i++) {
Suchakhree 0:238df339023b 675 destination[i] = 100.0*((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i]; // Report percent differences
Suchakhree 0:238df339023b 676 destination[i+3] = 100.0*((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3]; // Report percent differences
Suchakhree 0:238df339023b 677 }
Suchakhree 0:238df339023b 678 }
Suchakhree 0:238df339023b 679
Suchakhree 0:238df339023b 680
Suchakhree 0:238df339023b 681
Suchakhree 0:238df339023b 682 void getCompassOrientation(float * orient){ // Obtains the orientation of the device in degrees. 0 degrees North. 180 degrees South.
Suchakhree 0:238df339023b 683 /*
Suchakhree 0:238df339023b 684 Remember that it is the earth's rotational axis that defines the geographic north and south poles that we use for map references.
Suchakhree 0:238df339023b 685 It turns out that there is a discrepancy of about 11.5 degrees between the geographic poles and the magnetic poles. The last is
Suchakhree 0:238df339023b 686 what the magnetometer will read. A value, called the declination angle, can be applied to the magnetic direction to correct for this.
Suchakhree 0:238df339023b 687 On Valencia (Spain) this value is about 0 degrees.
Suchakhree 0:238df339023b 688 */
Suchakhree 0:238df339023b 689
Suchakhree 0:238df339023b 690 // First of all measure 3 axis magnetometer values (only X and Y axis is used):
Suchakhree 0:238df339023b 691 readMagData(magCount); // Read the x/y/z adc values
Suchakhree 0:238df339023b 692 // Calculate the magnetometer values in milliGauss
Suchakhree 0:238df339023b 693 // Include factory calibration per data sheet and user environmental corrections
Suchakhree 0:238df339023b 694 if (I2Cstate == 0){ // no error on I2C
Suchakhree 0:238df339023b 695 I2Cstate = 1;
Suchakhree 0:238df339023b 696 magn_x = (float)magCount[0]*mRes*magCalibration[0] - magbias[0]; // get actual magnetometer value, this depends on scale being set
Suchakhree 0:238df339023b 697 magn_y = (float)magCount[1]*mRes*magCalibration[1] - magbias[1];
Suchakhree 0:238df339023b 698 }
Suchakhree 0:238df339023b 699
Suchakhree 0:238df339023b 700 // Now obtains the orientation value:
Suchakhree 0:238df339023b 701 if (magn_y>0)
Suchakhree 0:238df339023b 702 orient[0] = 90.0 - (float) ( atan(magn_x/magn_y)*180/M_PI );
Suchakhree 0:238df339023b 703 else if (magn_y<0)
Suchakhree 0:238df339023b 704 orient[0] = 270.0 - (float) ( atan(magn_x/magn_y)*180/M_PI );
Suchakhree 0:238df339023b 705 else if (magn_y == 0){
Suchakhree 0:238df339023b 706 if (magn_x<0)
Suchakhree 0:238df339023b 707 orient[0] = 180.0;
Suchakhree 0:238df339023b 708 else
Suchakhree 0:238df339023b 709 orient[0] = 0.0;
Suchakhree 0:238df339023b 710 }
Suchakhree 0:238df339023b 711 }
Suchakhree 0:238df339023b 712
Suchakhree 0:238df339023b 713
Suchakhree 0:238df339023b 714
Suchakhree 0:238df339023b 715
Suchakhree 0:238df339023b 716
Suchakhree 0:238df339023b 717
Suchakhree 0:238df339023b 718 // Implementation of Sebastian Madgwick's "...efficient orientation filter for... inertial/magnetic sensor arrays"
Suchakhree 0:238df339023b 719 // (see http://www.x-io.co.uk/category/open-source/ for examples and more details)
Suchakhree 0:238df339023b 720 // which fuses acceleration, rotation rate, and magnetic moments to produce a quaternion-based estimate of absolute
Suchakhree 0:238df339023b 721 // device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc.
Suchakhree 0:238df339023b 722 // The performance of the orientation filter is at least as good as conventional Kalman-based filtering algorithms
Suchakhree 0:238df339023b 723 // but is much less computationally intensive---it can be performed on a 3.3 V Pro Mini operating at 8 MHz!
Suchakhree 0:238df339023b 724 void MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
Suchakhree 0:238df339023b 725 {
Suchakhree 0:238df339023b 726 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
Suchakhree 0:238df339023b 727 float norm;
Suchakhree 0:238df339023b 728 float hx, hy, _2bx, _2bz;
Suchakhree 0:238df339023b 729 float s1, s2, s3, s4;
Suchakhree 0:238df339023b 730 float qDot1, qDot2, qDot3, qDot4;
Suchakhree 0:238df339023b 731
Suchakhree 0:238df339023b 732 // Auxiliary variables to avoid repeated arithmetic
Suchakhree 0:238df339023b 733 float _2q1mx;
Suchakhree 0:238df339023b 734 float _2q1my;
Suchakhree 0:238df339023b 735 float _2q1mz;
Suchakhree 0:238df339023b 736 float _2q2mx;
Suchakhree 0:238df339023b 737 float _4bx;
Suchakhree 0:238df339023b 738 float _4bz;
Suchakhree 0:238df339023b 739 float _2q1 = 2.0f * q1;
Suchakhree 0:238df339023b 740 float _2q2 = 2.0f * q2;
Suchakhree 0:238df339023b 741 float _2q3 = 2.0f * q3;
Suchakhree 0:238df339023b 742 float _2q4 = 2.0f * q4;
Suchakhree 0:238df339023b 743 float _2q1q3 = 2.0f * q1 * q3;
Suchakhree 0:238df339023b 744 float _2q3q4 = 2.0f * q3 * q4;
Suchakhree 0:238df339023b 745 float q1q1 = q1 * q1;
Suchakhree 0:238df339023b 746 float q1q2 = q1 * q2;
Suchakhree 0:238df339023b 747 float q1q3 = q1 * q3;
Suchakhree 0:238df339023b 748 float q1q4 = q1 * q4;
Suchakhree 0:238df339023b 749 float q2q2 = q2 * q2;
Suchakhree 0:238df339023b 750 float q2q3 = q2 * q3;
Suchakhree 0:238df339023b 751 float q2q4 = q2 * q4;
Suchakhree 0:238df339023b 752 float q3q3 = q3 * q3;
Suchakhree 0:238df339023b 753 float q3q4 = q3 * q4;
Suchakhree 0:238df339023b 754 float q4q4 = q4 * q4;
Suchakhree 0:238df339023b 755
Suchakhree 0:238df339023b 756 // Normalise accelerometer measurement
Suchakhree 0:238df339023b 757 norm = sqrt(ax * ax + ay * ay + az * az);
Suchakhree 0:238df339023b 758 if (norm == 0.0f) return; // handle NaN
Suchakhree 0:238df339023b 759 norm = 1.0f/norm;
Suchakhree 0:238df339023b 760 ax *= norm;
Suchakhree 0:238df339023b 761 ay *= norm;
Suchakhree 0:238df339023b 762 az *= norm;
Suchakhree 0:238df339023b 763
Suchakhree 0:238df339023b 764 // Normalise magnetometer measurement
Suchakhree 0:238df339023b 765 norm = sqrt(mx * mx + my * my + mz * mz);
Suchakhree 0:238df339023b 766 if (norm == 0.0f) return; // handle NaN
Suchakhree 0:238df339023b 767 norm = 1.0f/norm;
Suchakhree 0:238df339023b 768 mx *= norm;
Suchakhree 0:238df339023b 769 my *= norm;
Suchakhree 0:238df339023b 770 mz *= norm;
Suchakhree 0:238df339023b 771
Suchakhree 0:238df339023b 772 // Reference direction of Earth's magnetic field
Suchakhree 0:238df339023b 773 _2q1mx = 2.0f * q1 * mx;
Suchakhree 0:238df339023b 774 _2q1my = 2.0f * q1 * my;
Suchakhree 0:238df339023b 775 _2q1mz = 2.0f * q1 * mz;
Suchakhree 0:238df339023b 776 _2q2mx = 2.0f * q2 * mx;
Suchakhree 0:238df339023b 777 hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4;
Suchakhree 0:238df339023b 778 hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4;
Suchakhree 0:238df339023b 779 _2bx = sqrt(hx * hx + hy * hy);
Suchakhree 0:238df339023b 780 _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4;
Suchakhree 0:238df339023b 781 _4bx = 2.0f * _2bx;
Suchakhree 0:238df339023b 782 _4bz = 2.0f * _2bz;
Suchakhree 0:238df339023b 783
Suchakhree 0:238df339023b 784 // Gradient decent algorithm corrective step
Suchakhree 0:238df339023b 785 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);
Suchakhree 0:238df339023b 786 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);
Suchakhree 0:238df339023b 787 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);
Suchakhree 0:238df339023b 788 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);
Suchakhree 0:238df339023b 789 norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4); // normalise step magnitude
Suchakhree 0:238df339023b 790 norm = 1.0f/norm;
Suchakhree 0:238df339023b 791 s1 *= norm;
Suchakhree 0:238df339023b 792 s2 *= norm;
Suchakhree 0:238df339023b 793 s3 *= norm;
Suchakhree 0:238df339023b 794 s4 *= norm;
Suchakhree 0:238df339023b 795
Suchakhree 0:238df339023b 796 // Compute rate of change of quaternion
Suchakhree 0:238df339023b 797 qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1;
Suchakhree 0:238df339023b 798 qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2;
Suchakhree 0:238df339023b 799 qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3;
Suchakhree 0:238df339023b 800 qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4;
Suchakhree 0:238df339023b 801
Suchakhree 0:238df339023b 802 // Integrate to yield quaternion
Suchakhree 0:238df339023b 803 q1 += qDot1 * deltat;
Suchakhree 0:238df339023b 804 q2 += qDot2 * deltat;
Suchakhree 0:238df339023b 805 q3 += qDot3 * deltat;
Suchakhree 0:238df339023b 806 q4 += qDot4 * deltat;
Suchakhree 0:238df339023b 807 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion
Suchakhree 0:238df339023b 808 norm = 1.0f/norm;
Suchakhree 0:238df339023b 809 q[0] = q1 * norm;
Suchakhree 0:238df339023b 810 q[1] = q2 * norm;
Suchakhree 0:238df339023b 811 q[2] = q3 * norm;
Suchakhree 0:238df339023b 812 q[3] = q4 * norm;
Suchakhree 0:238df339023b 813
Suchakhree 0:238df339023b 814 }
Suchakhree 0:238df339023b 815
Suchakhree 0:238df339023b 816
Suchakhree 0:238df339023b 817
Suchakhree 0:238df339023b 818 // Similar to Madgwick scheme but uses proportional and integral filtering on the error between estimated reference vectors and
Suchakhree 0:238df339023b 819 // measured ones.
Suchakhree 0:238df339023b 820 void MahonyQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
Suchakhree 0:238df339023b 821 {
Suchakhree 0:238df339023b 822 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
Suchakhree 0:238df339023b 823 float norm;
Suchakhree 0:238df339023b 824 float hx, hy, bx, bz;
Suchakhree 0:238df339023b 825 float vx, vy, vz, wx, wy, wz;
Suchakhree 0:238df339023b 826 float ex, ey, ez;
Suchakhree 0:238df339023b 827 float pa, pb, pc;
Suchakhree 0:238df339023b 828
Suchakhree 0:238df339023b 829 // Auxiliary variables to avoid repeated arithmetic
Suchakhree 0:238df339023b 830 float q1q1 = q1 * q1;
Suchakhree 0:238df339023b 831 float q1q2 = q1 * q2;
Suchakhree 0:238df339023b 832 float q1q3 = q1 * q3;
Suchakhree 0:238df339023b 833 float q1q4 = q1 * q4;
Suchakhree 0:238df339023b 834 float q2q2 = q2 * q2;
Suchakhree 0:238df339023b 835 float q2q3 = q2 * q3;
Suchakhree 0:238df339023b 836 float q2q4 = q2 * q4;
Suchakhree 0:238df339023b 837 float q3q3 = q3 * q3;
Suchakhree 0:238df339023b 838 float q3q4 = q3 * q4;
Suchakhree 0:238df339023b 839 float q4q4 = q4 * q4;
Suchakhree 0:238df339023b 840
Suchakhree 0:238df339023b 841 // Normalise accelerometer measurement
Suchakhree 0:238df339023b 842 norm = sqrt(ax * ax + ay * ay + az * az);
Suchakhree 0:238df339023b 843 if (norm == 0.0f) return; // handle NaN
Suchakhree 0:238df339023b 844 norm = 1.0f / norm; // use reciprocal for division
Suchakhree 0:238df339023b 845 ax *= norm;
Suchakhree 0:238df339023b 846 ay *= norm;
Suchakhree 0:238df339023b 847 az *= norm;
Suchakhree 0:238df339023b 848
Suchakhree 0:238df339023b 849 // Normalise magnetometer measurement
Suchakhree 0:238df339023b 850 norm = sqrt(mx * mx + my * my + mz * mz);
Suchakhree 0:238df339023b 851 if (norm == 0.0f) return; // handle NaN
Suchakhree 0:238df339023b 852 norm = 1.0f / norm; // use reciprocal for division
Suchakhree 0:238df339023b 853 mx *= norm;
Suchakhree 0:238df339023b 854 my *= norm;
Suchakhree 0:238df339023b 855 mz *= norm;
Suchakhree 0:238df339023b 856
Suchakhree 0:238df339023b 857 // Reference direction of Earth's magnetic field
Suchakhree 0:238df339023b 858 hx = 2.0f * mx * (0.5f - q3q3 - q4q4) + 2.0f * my * (q2q3 - q1q4) + 2.0f * mz * (q2q4 + q1q3);
Suchakhree 0:238df339023b 859 hy = 2.0f * mx * (q2q3 + q1q4) + 2.0f * my * (0.5f - q2q2 - q4q4) + 2.0f * mz * (q3q4 - q1q2);
Suchakhree 0:238df339023b 860 bx = sqrt((hx * hx) + (hy * hy));
Suchakhree 0:238df339023b 861 bz = 2.0f * mx * (q2q4 - q1q3) + 2.0f * my * (q3q4 + q1q2) + 2.0f * mz * (0.5f - q2q2 - q3q3);
Suchakhree 0:238df339023b 862
Suchakhree 0:238df339023b 863 // Estimated direction of gravity and magnetic field
Suchakhree 0:238df339023b 864 vx = 2.0f * (q2q4 - q1q3);
Suchakhree 0:238df339023b 865 vy = 2.0f * (q1q2 + q3q4);
Suchakhree 0:238df339023b 866 vz = q1q1 - q2q2 - q3q3 + q4q4;
Suchakhree 0:238df339023b 867 wx = 2.0f * bx * (0.5f - q3q3 - q4q4) + 2.0f * bz * (q2q4 - q1q3);
Suchakhree 0:238df339023b 868 wy = 2.0f * bx * (q2q3 - q1q4) + 2.0f * bz * (q1q2 + q3q4);
Suchakhree 0:238df339023b 869 wz = 2.0f * bx * (q1q3 + q2q4) + 2.0f * bz * (0.5f - q2q2 - q3q3);
Suchakhree 0:238df339023b 870
Suchakhree 0:238df339023b 871 // Error is cross product between estimated direction and measured direction of gravity
Suchakhree 0:238df339023b 872 ex = (ay * vz - az * vy) + (my * wz - mz * wy);
Suchakhree 0:238df339023b 873 ey = (az * vx - ax * vz) + (mz * wx - mx * wz);
Suchakhree 0:238df339023b 874 ez = (ax * vy - ay * vx) + (mx * wy - my * wx);
Suchakhree 0:238df339023b 875 if (Ki > 0.0f)
Suchakhree 0:238df339023b 876 {
Suchakhree 0:238df339023b 877 eInt[0] += ex; // accumulate integral error
Suchakhree 0:238df339023b 878 eInt[1] += ey;
Suchakhree 0:238df339023b 879 eInt[2] += ez;
Suchakhree 0:238df339023b 880 }
Suchakhree 0:238df339023b 881 else
Suchakhree 0:238df339023b 882 {
Suchakhree 0:238df339023b 883 eInt[0] = 0.0f; // prevent integral wind up
Suchakhree 0:238df339023b 884 eInt[1] = 0.0f;
Suchakhree 0:238df339023b 885 eInt[2] = 0.0f;
Suchakhree 0:238df339023b 886 }
Suchakhree 0:238df339023b 887
Suchakhree 0:238df339023b 888 // Apply feedback terms
Suchakhree 0:238df339023b 889 gx = gx + Kp * ex + Ki * eInt[0];
Suchakhree 0:238df339023b 890 gy = gy + Kp * ey + Ki * eInt[1];
Suchakhree 0:238df339023b 891 gz = gz + Kp * ez + Ki * eInt[2];
Suchakhree 0:238df339023b 892
Suchakhree 0:238df339023b 893 // Integrate rate of change of quaternion
Suchakhree 0:238df339023b 894 pa = q2;
Suchakhree 0:238df339023b 895 pb = q3;
Suchakhree 0:238df339023b 896 pc = q4;
Suchakhree 0:238df339023b 897 q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * deltat);
Suchakhree 0:238df339023b 898 q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * deltat);
Suchakhree 0:238df339023b 899 q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * deltat);
Suchakhree 0:238df339023b 900 q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * deltat);
Suchakhree 0:238df339023b 901
Suchakhree 0:238df339023b 902 // Normalise quaternion
Suchakhree 0:238df339023b 903 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);
Suchakhree 0:238df339023b 904 norm = 1.0f / norm;
Suchakhree 0:238df339023b 905 q[0] = q1 * norm;
Suchakhree 0:238df339023b 906 q[1] = q2 * norm;
Suchakhree 0:238df339023b 907 q[2] = q3 * norm;
Suchakhree 0:238df339023b 908 q[3] = q4 * norm;
Suchakhree 0:238df339023b 909
Suchakhree 0:238df339023b 910 }
Suchakhree 0:238df339023b 911 };
Suchakhree 0:238df339023b 912 #endif