Cristian Castro / MPU9250

MPU9250 Basic Example Code

MPU9250.h@2:55ab1dcffe0c, 2021-09-03 (annotated)

Committer:
CCastrop1012
Date:
Fri Sep 03 04:53:40 2021 +0000
Revision:
2:55ab1dcffe0c
Parent:
1:fc94c7336b7c 
MPU9250 Basic Example Code

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ruevs 0:2315cd1878a1 1 #ifndef MPU9250_H
ruevs 0:2315cd1878a1 2 #define MPU9250_H
ruevs 0:2315cd1878a1 3
ruevs 0:2315cd1878a1 4 #include "mbed.h"
ruevs 0:2315cd1878a1 5 #include "math.h"
ruevs 0:2315cd1878a1 6
ruevs 0:2315cd1878a1 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
ruevs 0:2315cd1878a1 8 // above document; the MPU9250 and MPU9150 are virtually identical but the latter has a different register map
ruevs 0:2315cd1878a1 9 //
ruevs 0:2315cd1878a1 10 //Magnetometer Registers
ruevs 0:2315cd1878a1 11 #define AK8963_ADDRESS 0x0C<<1
ruevs 0:2315cd1878a1 12 #define WHO_AM_I_AK8963 0x00 // should return 0x48
ruevs 0:2315cd1878a1 13 #define INFO 0x01
ruevs 0:2315cd1878a1 14 #define AK8963_ST1 0x02 // data ready status bit 0
ruevs 0:2315cd1878a1 15 #define AK8963_XOUT_L 0x03 // data
ruevs 0:2315cd1878a1 16 #define AK8963_XOUT_H 0x04
ruevs 0:2315cd1878a1 17 #define AK8963_YOUT_L 0x05
ruevs 0:2315cd1878a1 18 #define AK8963_YOUT_H 0x06
ruevs 0:2315cd1878a1 19 #define AK8963_ZOUT_L 0x07
ruevs 0:2315cd1878a1 20 #define AK8963_ZOUT_H 0x08
ruevs 0:2315cd1878a1 21 #define AK8963_ST2 0x09 // Data overflow bit 3 and data read error status bit 2
ruevs 0:2315cd1878a1 22 #define AK8963_CNTL 0x0A // Power down (0000), single-measurement (0001), self-test (1000) and Fuse ROM (1111) modes on bits 3:0
ruevs 0:2315cd1878a1 23 #define AK8963_ASTC 0x0C // Self test control
ruevs 0:2315cd1878a1 24 #define AK8963_I2CDIS 0x0F // I2C disable
ruevs 0:2315cd1878a1 25 #define AK8963_ASAX 0x10 // Fuse ROM x-axis sensitivity adjustment value
ruevs 0:2315cd1878a1 26 #define AK8963_ASAY 0x11 // Fuse ROM y-axis sensitivity adjustment value
ruevs 0:2315cd1878a1 27 #define AK8963_ASAZ 0x12 // Fuse ROM z-axis sensitivity adjustment value
ruevs 0:2315cd1878a1 28
ruevs 0:2315cd1878a1 29 #define SELF_TEST_X_GYRO 0x00
ruevs 0:2315cd1878a1 30 #define SELF_TEST_Y_GYRO 0x01
ruevs 0:2315cd1878a1 31 #define SELF_TEST_Z_GYRO 0x02
ruevs 0:2315cd1878a1 32
ruevs 0:2315cd1878a1 33 /*#define X_FINE_GAIN 0x03 // [7:0] fine gain
ruevs 0:2315cd1878a1 34 #define Y_FINE_GAIN 0x04
ruevs 0:2315cd1878a1 35 #define Z_FINE_GAIN 0x05
ruevs 0:2315cd1878a1 36 #define XA_OFFSET_H 0x06 // User-defined trim values for accelerometer
ruevs 0:2315cd1878a1 37 #define XA_OFFSET_L_TC 0x07
ruevs 0:2315cd1878a1 38 #define YA_OFFSET_H 0x08
ruevs 0:2315cd1878a1 39 #define YA_OFFSET_L_TC 0x09
ruevs 0:2315cd1878a1 40 #define ZA_OFFSET_H 0x0A
ruevs 0:2315cd1878a1 41 #define ZA_OFFSET_L_TC 0x0B */
ruevs 0:2315cd1878a1 42
ruevs 0:2315cd1878a1 43 #define SELF_TEST_X_ACCEL 0x0D
ruevs 0:2315cd1878a1 44 #define SELF_TEST_Y_ACCEL 0x0E
ruevs 0:2315cd1878a1 45 #define SELF_TEST_Z_ACCEL 0x0F
ruevs 0:2315cd1878a1 46
ruevs 0:2315cd1878a1 47 #define SELF_TEST_A 0x10
ruevs 0:2315cd1878a1 48
ruevs 0:2315cd1878a1 49 #define XG_OFFSET_H 0x13 // User-defined trim values for gyroscope
ruevs 0:2315cd1878a1 50 #define XG_OFFSET_L 0x14
ruevs 0:2315cd1878a1 51 #define YG_OFFSET_H 0x15
ruevs 0:2315cd1878a1 52 #define YG_OFFSET_L 0x16
ruevs 0:2315cd1878a1 53 #define ZG_OFFSET_H 0x17
ruevs 0:2315cd1878a1 54 #define ZG_OFFSET_L 0x18
ruevs 0:2315cd1878a1 55 #define SMPLRT_DIV 0x19
ruevs 0:2315cd1878a1 56 #define CONFIG 0x1A
ruevs 0:2315cd1878a1 57 #define GYRO_CONFIG 0x1B
ruevs 0:2315cd1878a1 58 #define ACCEL_CONFIG 0x1C
ruevs 0:2315cd1878a1 59 #define ACCEL_CONFIG2 0x1D
ruevs 0:2315cd1878a1 60 #define LP_ACCEL_ODR 0x1E
ruevs 0:2315cd1878a1 61 #define WOM_THR 0x1F
ruevs 0:2315cd1878a1 62
ruevs 0:2315cd1878a1 63 #define MOT_DUR 0x20 // Duration counter threshold for motion interrupt generation, 1 kHz rate, LSB = 1 ms
ruevs 0:2315cd1878a1 64 #define ZMOT_THR 0x21 // Zero-motion detection threshold bits [7:0]
ruevs 0:2315cd1878a1 65 #define ZRMOT_DUR 0x22 // Duration counter threshold for zero motion interrupt generation, 16 Hz rate, LSB = 64 ms
ruevs 0:2315cd1878a1 66
ruevs 0:2315cd1878a1 67 #define FIFO_EN 0x23
ruevs 0:2315cd1878a1 68 #define I2C_MST_CTRL 0x24
ruevs 0:2315cd1878a1 69 #define I2C_SLV0_ADDR 0x25
ruevs 0:2315cd1878a1 70 #define I2C_SLV0_REG 0x26
ruevs 0:2315cd1878a1 71 #define I2C_SLV0_CTRL 0x27
ruevs 0:2315cd1878a1 72 #define I2C_SLV1_ADDR 0x28
ruevs 0:2315cd1878a1 73 #define I2C_SLV1_REG 0x29
ruevs 0:2315cd1878a1 74 #define I2C_SLV1_CTRL 0x2A
ruevs 0:2315cd1878a1 75 #define I2C_SLV2_ADDR 0x2B
ruevs 0:2315cd1878a1 76 #define I2C_SLV2_REG 0x2C
ruevs 0:2315cd1878a1 77 #define I2C_SLV2_CTRL 0x2D
ruevs 0:2315cd1878a1 78 #define I2C_SLV3_ADDR 0x2E
ruevs 0:2315cd1878a1 79 #define I2C_SLV3_REG 0x2F
ruevs 0:2315cd1878a1 80 #define I2C_SLV3_CTRL 0x30
ruevs 0:2315cd1878a1 81 #define I2C_SLV4_ADDR 0x31
ruevs 0:2315cd1878a1 82 #define I2C_SLV4_REG 0x32
ruevs 0:2315cd1878a1 83 #define I2C_SLV4_DO 0x33
ruevs 0:2315cd1878a1 84 #define I2C_SLV4_CTRL 0x34
ruevs 0:2315cd1878a1 85 #define I2C_SLV4_DI 0x35
ruevs 0:2315cd1878a1 86 #define I2C_MST_STATUS 0x36
ruevs 0:2315cd1878a1 87 #define INT_PIN_CFG 0x37
ruevs 0:2315cd1878a1 88 #define INT_ENABLE 0x38
ruevs 0:2315cd1878a1 89 #define DMP_INT_STATUS 0x39 // Check DMP interrupt
ruevs 0:2315cd1878a1 90 #define INT_STATUS 0x3A
ruevs 0:2315cd1878a1 91 #define ACCEL_XOUT_H 0x3B
ruevs 0:2315cd1878a1 92 #define ACCEL_XOUT_L 0x3C
ruevs 0:2315cd1878a1 93 #define ACCEL_YOUT_H 0x3D
ruevs 0:2315cd1878a1 94 #define ACCEL_YOUT_L 0x3E
ruevs 0:2315cd1878a1 95 #define ACCEL_ZOUT_H 0x3F
ruevs 0:2315cd1878a1 96 #define ACCEL_ZOUT_L 0x40
ruevs 0:2315cd1878a1 97 #define TEMP_OUT_H 0x41
ruevs 0:2315cd1878a1 98 #define TEMP_OUT_L 0x42
ruevs 0:2315cd1878a1 99 #define GYRO_XOUT_H 0x43
ruevs 0:2315cd1878a1 100 #define GYRO_XOUT_L 0x44
ruevs 0:2315cd1878a1 101 #define GYRO_YOUT_H 0x45
ruevs 0:2315cd1878a1 102 #define GYRO_YOUT_L 0x46
ruevs 0:2315cd1878a1 103 #define GYRO_ZOUT_H 0x47
ruevs 0:2315cd1878a1 104 #define GYRO_ZOUT_L 0x48
ruevs 0:2315cd1878a1 105 #define EXT_SENS_DATA_00 0x49
ruevs 0:2315cd1878a1 106 #define EXT_SENS_DATA_01 0x4A
ruevs 0:2315cd1878a1 107 #define EXT_SENS_DATA_02 0x4B
ruevs 0:2315cd1878a1 108 #define EXT_SENS_DATA_03 0x4C
ruevs 0:2315cd1878a1 109 #define EXT_SENS_DATA_04 0x4D
ruevs 0:2315cd1878a1 110 #define EXT_SENS_DATA_05 0x4E
ruevs 0:2315cd1878a1 111 #define EXT_SENS_DATA_06 0x4F
ruevs 0:2315cd1878a1 112 #define EXT_SENS_DATA_07 0x50
ruevs 0:2315cd1878a1 113 #define EXT_SENS_DATA_08 0x51
ruevs 0:2315cd1878a1 114 #define EXT_SENS_DATA_09 0x52
ruevs 0:2315cd1878a1 115 #define EXT_SENS_DATA_10 0x53
ruevs 0:2315cd1878a1 116 #define EXT_SENS_DATA_11 0x54
ruevs 0:2315cd1878a1 117 #define EXT_SENS_DATA_12 0x55
ruevs 0:2315cd1878a1 118 #define EXT_SENS_DATA_13 0x56
ruevs 0:2315cd1878a1 119 #define EXT_SENS_DATA_14 0x57
ruevs 0:2315cd1878a1 120 #define EXT_SENS_DATA_15 0x58
ruevs 0:2315cd1878a1 121 #define EXT_SENS_DATA_16 0x59
ruevs 0:2315cd1878a1 122 #define EXT_SENS_DATA_17 0x5A
ruevs 0:2315cd1878a1 123 #define EXT_SENS_DATA_18 0x5B
ruevs 0:2315cd1878a1 124 #define EXT_SENS_DATA_19 0x5C
ruevs 0:2315cd1878a1 125 #define EXT_SENS_DATA_20 0x5D
ruevs 0:2315cd1878a1 126 #define EXT_SENS_DATA_21 0x5E
ruevs 0:2315cd1878a1 127 #define EXT_SENS_DATA_22 0x5F
ruevs 0:2315cd1878a1 128 #define EXT_SENS_DATA_23 0x60
ruevs 0:2315cd1878a1 129 #define MOT_DETECT_STATUS 0x61
ruevs 0:2315cd1878a1 130 #define I2C_SLV0_DO 0x63
ruevs 0:2315cd1878a1 131 #define I2C_SLV1_DO 0x64
ruevs 0:2315cd1878a1 132 #define I2C_SLV2_DO 0x65
ruevs 0:2315cd1878a1 133 #define I2C_SLV3_DO 0x66
ruevs 0:2315cd1878a1 134 #define I2C_MST_DELAY_CTRL 0x67
ruevs 0:2315cd1878a1 135 #define SIGNAL_PATH_RESET 0x68
ruevs 0:2315cd1878a1 136 #define MOT_DETECT_CTRL 0x69
ruevs 0:2315cd1878a1 137 #define USER_CTRL 0x6A // Bit 7 enable DMP, bit 3 reset DMP
ruevs 0:2315cd1878a1 138 #define PWR_MGMT_1 0x6B // Device defaults to the SLEEP mode
ruevs 0:2315cd1878a1 139 #define PWR_MGMT_2 0x6C
ruevs 0:2315cd1878a1 140 #define DMP_BANK 0x6D // Activates a specific bank in the DMP
ruevs 0:2315cd1878a1 141 #define DMP_RW_PNT 0x6E // Set read/write pointer to a specific start address in specified DMP bank
ruevs 0:2315cd1878a1 142 #define DMP_REG 0x6F // Register in DMP from which to read or to which to write
ruevs 0:2315cd1878a1 143 #define DMP_REG_1 0x70
ruevs 0:2315cd1878a1 144 #define DMP_REG_2 0x71
ruevs 0:2315cd1878a1 145 #define FIFO_COUNTH 0x72
ruevs 0:2315cd1878a1 146 #define FIFO_COUNTL 0x73
ruevs 0:2315cd1878a1 147 #define FIFO_R_W 0x74
ruevs 0:2315cd1878a1 148 #define WHO_AM_I_MPU9250 0x75 // Should return 0x71
ruevs 0:2315cd1878a1 149 #define XA_OFFSET_H 0x77
ruevs 0:2315cd1878a1 150 #define XA_OFFSET_L 0x78
ruevs 0:2315cd1878a1 151 #define YA_OFFSET_H 0x7A
ruevs 0:2315cd1878a1 152 #define YA_OFFSET_L 0x7B
ruevs 0:2315cd1878a1 153 #define ZA_OFFSET_H 0x7D
ruevs 0:2315cd1878a1 154 #define ZA_OFFSET_L 0x7E
ruevs 0:2315cd1878a1 155
ruevs 0:2315cd1878a1 156 // Using the MSENSR-9250 breakout board, ADO is set to 0
ruevs 0:2315cd1878a1 157 // Seven-bit device address is 110100 for ADO = 0 and 110101 for ADO = 1
ruevs 0:2315cd1878a1 158 //mbed uses the eight-bit device address, so shift seven-bit addresses left by one!
ruevs 0:2315cd1878a1 159 #define ADO 0
ruevs 0:2315cd1878a1 160 #if ADO
ruevs 0:2315cd1878a1 161 #define MPU9250_ADDRESS 0x69<<1 // Device address when ADO = 1
ruevs 0:2315cd1878a1 162 #else
ruevs 0:2315cd1878a1 163 #define MPU9250_ADDRESS 0x68<<1 // Device address when ADO = 0
ruevs 0:2315cd1878a1 164 #endif
ruevs 0:2315cd1878a1 165
ruevs 0:2315cd1878a1 166 // Set initial input parameters
ruevs 0:2315cd1878a1 167 enum Ascale {
ruevs 0:2315cd1878a1 168 AFS_2G = 0,
ruevs 0:2315cd1878a1 169 AFS_4G,
ruevs 0:2315cd1878a1 170 AFS_8G,
ruevs 0:2315cd1878a1 171 AFS_16G
ruevs 0:2315cd1878a1 172 };
ruevs 0:2315cd1878a1 173
ruevs 0:2315cd1878a1 174 enum Gscale {
ruevs 0:2315cd1878a1 175 GFS_250DPS = 0,
ruevs 0:2315cd1878a1 176 GFS_500DPS,
ruevs 0:2315cd1878a1 177 GFS_1000DPS,
ruevs 0:2315cd1878a1 178 GFS_2000DPS
ruevs 0:2315cd1878a1 179 };
ruevs 0:2315cd1878a1 180
ruevs 0:2315cd1878a1 181 enum Mscale {
ruevs 0:2315cd1878a1 182 MFS_14BITS = 0, // 0.6 mG per LSB
ruevs 0:2315cd1878a1 183 MFS_16BITS // 0.15 mG per LSB
ruevs 0:2315cd1878a1 184 };
ruevs 0:2315cd1878a1 185
ruevs 0:2315cd1878a1 186 uint8_t Ascale = AFS_2G; // AFS_2G, AFS_4G, AFS_8G, AFS_16G
ruevs 0:2315cd1878a1 187 uint8_t Gscale = GFS_250DPS; // GFS_250DPS, GFS_500DPS, GFS_1000DPS, GFS_2000DPS
ruevs 0:2315cd1878a1 188 uint8_t Mscale = MFS_16BITS; // MFS_14BITS or MFS_16BITS, 14-bit or 16-bit magnetometer resolution
ruevs 0:2315cd1878a1 189 uint8_t Mmode = 0x06; // Either 8 Hz 0x02) or 100 Hz (0x06) magnetometer data ODR
ruevs 0:2315cd1878a1 190 float aRes, gRes, mRes; // scale resolutions per LSB for the sensors
ruevs 0:2315cd1878a1 191
ruevs 0:2315cd1878a1 192 //Set up I2C, (SDA,SCL)
CCastrop1012 2:55ab1dcffe0c 193 I2C i2c(I2C_SDA, I2C_SCL);
ruevs 0:2315cd1878a1 194
ruevs 0:2315cd1878a1 195 DigitalOut myled(LED1);
ruevs 0:2315cd1878a1 196
ruevs 0:2315cd1878a1 197 // Pin definitions
ruevs 0:2315cd1878a1 198 int intPin = 12; // These can be changed, 2 and 3 are the Arduinos ext int pins
ruevs 0:2315cd1878a1 199
ruevs 0:2315cd1878a1 200 int16_t accelCount[3]; // Stores the 16-bit signed accelerometer sensor output
ruevs 0:2315cd1878a1 201 int16_t gyroCount[3]; // Stores the 16-bit signed gyro sensor output
ruevs 0:2315cd1878a1 202 int16_t magCount[3]; // Stores the 16-bit signed magnetometer sensor output
ruevs 0:2315cd1878a1 203 float magCalibration[3] = {0, 0, 0}, magbias[3] = {0, 0, 0}; // Factory mag calibration and mag bias
ruevs 0:2315cd1878a1 204 float gyroBias[3] = {0, 0, 0}, accelBias[3] = {0, 0, 0}; // Bias corrections for gyro and accelerometer
ruevs 0:2315cd1878a1 205 float ax, ay, az, gx, gy, gz, mx, my, mz; // variables to hold latest sensor data values
ruevs 0:2315cd1878a1 206 int16_t tempCount; // Stores the real internal chip temperature in degrees Celsius
ruevs 0:2315cd1878a1 207 float temperature;
ruevs 0:2315cd1878a1 208 float SelfTest[6];
ruevs 0:2315cd1878a1 209
ruevs 0:2315cd1878a1 210 int delt_t = 0; // used to control display output rate
ruevs 0:2315cd1878a1 211 int count = 0; // used to control display output rate
ruevs 0:2315cd1878a1 212
ruevs 0:2315cd1878a1 213 // parameters for 6 DoF sensor fusion calculations
ruevs 0:2315cd1878a1 214 float PI = 3.14159265358979323846f;
ruevs 0:2315cd1878a1 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
ruevs 0:2315cd1878a1 216 float beta = sqrt(3.0f / 4.0f) * GyroMeasError; // compute beta
ruevs 0:2315cd1878a1 217 float GyroMeasDrift = PI * (1.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
ruevs 0:2315cd1878a1 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
ruevs 0:2315cd1878a1 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
ruevs 0:2315cd1878a1 220 #define Ki 0.0f
ruevs 0:2315cd1878a1 221
ruevs 0:2315cd1878a1 222 float pitch, yaw, roll;
ruevs 0:2315cd1878a1 223 float deltat = 0.0f; // integration interval for both filter schemes
ruevs 0:2315cd1878a1 224 int lastUpdate = 0, firstUpdate = 0, Now = 0; // used to calculate integration interval // used to calculate integration interval
ruevs 0:2315cd1878a1 225 float q[4] = {1.0f, 0.0f, 0.0f, 0.0f}; // vector to hold quaternion
ruevs 0:2315cd1878a1 226 float eInt[3] = {0.0f, 0.0f, 0.0f}; // vector to hold integral error for Mahony method
ruevs 0:2315cd1878a1 227
ruevs 0:2315cd1878a1 228 class MPU9250 {
CCastrop1012 2:55ab1dcffe0c 229
ruevs 0:2315cd1878a1 230 protected:
ruevs 0:2315cd1878a1 231
ruevs 0:2315cd1878a1 232 public:
CCastrop1012 2:55ab1dcffe0c 233 //===================================================================================================================
CCastrop1012 2:55ab1dcffe0c 234 //====== Set of useful function to access acceleratio, gyroscope, and temperature data
CCastrop1012 2:55ab1dcffe0c 235 //===================================================================================================================
ruevs 0:2315cd1878a1 236
ruevs 0:2315cd1878a1 237 void writeByte(uint8_t address, uint8_t subAddress, uint8_t data)
CCastrop1012 2:55ab1dcffe0c 238 {
CCastrop1012 2:55ab1dcffe0c 239 char data_write[2];
CCastrop1012 2:55ab1dcffe0c 240 data_write[0] = subAddress;
CCastrop1012 2:55ab1dcffe0c 241 data_write[1] = data;
CCastrop1012 2:55ab1dcffe0c 242 i2c.write(address, data_write, 2, 0);
CCastrop1012 2:55ab1dcffe0c 243 }
ruevs 0:2315cd1878a1 244
ruevs 0:2315cd1878a1 245 char readByte(uint8_t address, uint8_t subAddress)
CCastrop1012 2:55ab1dcffe0c 246 {
CCastrop1012 2:55ab1dcffe0c 247 char data[1]; // `data` will store the register data
CCastrop1012 2:55ab1dcffe0c 248 char data_write[1];
CCastrop1012 2:55ab1dcffe0c 249 data_write[0] = subAddress;
CCastrop1012 2:55ab1dcffe0c 250 i2c.write(address, data_write, 1, 1); // no stop
CCastrop1012 2:55ab1dcffe0c 251 i2c.read(address, data, 1, 0);
CCastrop1012 2:55ab1dcffe0c 252 return data[0];
CCastrop1012 2:55ab1dcffe0c 253 }
ruevs 0:2315cd1878a1 254
CCastrop1012 2:55ab1dcffe0c 255 void readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest)
CCastrop1012 2:55ab1dcffe0c 256 {
CCastrop1012 2:55ab1dcffe0c 257 char data[14];
CCastrop1012 2:55ab1dcffe0c 258 char data_write[1];
CCastrop1012 2:55ab1dcffe0c 259 data_write[0] = subAddress;
CCastrop1012 2:55ab1dcffe0c 260 i2c.write(address, data_write, 1, 1); // no stop
CCastrop1012 2:55ab1dcffe0c 261 i2c.read(address, data, count, 0);
CCastrop1012 2:55ab1dcffe0c 262 for(int ii = 0; ii < count; ii++) {
CCastrop1012 2:55ab1dcffe0c 263 dest[ii] = data[ii];
ruevs 0:2315cd1878a1 264 }
CCastrop1012 2:55ab1dcffe0c 265 }
ruevs 0:2315cd1878a1 266
ruevs 0:2315cd1878a1 267
CCastrop1012 2:55ab1dcffe0c 268 void getMres() {
CCastrop1012 2:55ab1dcffe0c 269 switch (Mscale)
CCastrop1012 2:55ab1dcffe0c 270 {
CCastrop1012 2:55ab1dcffe0c 271 // Possible magnetometer scales (and their register bit settings) are:
CCastrop1012 2:55ab1dcffe0c 272 // 14 bit resolution (0) and 16 bit resolution (1)
CCastrop1012 2:55ab1dcffe0c 273 case MFS_14BITS:
CCastrop1012 2:55ab1dcffe0c 274 mRes = 10.0*4219.0/8190.0; // Proper scale to return milliGauss
CCastrop1012 2:55ab1dcffe0c 275 break;
CCastrop1012 2:55ab1dcffe0c 276 case MFS_16BITS:
CCastrop1012 2:55ab1dcffe0c 277 mRes = 10.0*4219.0/32760.0; // Proper scale to return milliGauss
CCastrop1012 2:55ab1dcffe0c 278 break;
CCastrop1012 2:55ab1dcffe0c 279 }
CCastrop1012 2:55ab1dcffe0c 280 }
ruevs 0:2315cd1878a1 281
ruevs 0:2315cd1878a1 282
CCastrop1012 2:55ab1dcffe0c 283 void getGres() {
CCastrop1012 2:55ab1dcffe0c 284 switch (Gscale)
CCastrop1012 2:55ab1dcffe0c 285 {
CCastrop1012 2:55ab1dcffe0c 286 // Possible gyro scales (and their register bit settings) are:
CCastrop1012 2:55ab1dcffe0c 287 // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS (11).
CCastrop1012 2:55ab1dcffe0c 288 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
CCastrop1012 2:55ab1dcffe0c 289 case GFS_250DPS:
CCastrop1012 2:55ab1dcffe0c 290 gRes = 250.0/32768.0;
CCastrop1012 2:55ab1dcffe0c 291 break;
CCastrop1012 2:55ab1dcffe0c 292 case GFS_500DPS:
CCastrop1012 2:55ab1dcffe0c 293 gRes = 500.0/32768.0;
CCastrop1012 2:55ab1dcffe0c 294 break;
CCastrop1012 2:55ab1dcffe0c 295 case GFS_1000DPS:
CCastrop1012 2:55ab1dcffe0c 296 gRes = 1000.0/32768.0;
CCastrop1012 2:55ab1dcffe0c 297 break;
CCastrop1012 2:55ab1dcffe0c 298 case GFS_2000DPS:
CCastrop1012 2:55ab1dcffe0c 299 gRes = 2000.0/32768.0;
CCastrop1012 2:55ab1dcffe0c 300 break;
CCastrop1012 2:55ab1dcffe0c 301 }
CCastrop1012 2:55ab1dcffe0c 302 }
CCastrop1012 2:55ab1dcffe0c 303
ruevs 0:2315cd1878a1 304
CCastrop1012 2:55ab1dcffe0c 305 void getAres() {
CCastrop1012 2:55ab1dcffe0c 306 switch (Ascale)
CCastrop1012 2:55ab1dcffe0c 307 {
CCastrop1012 2:55ab1dcffe0c 308 // Possible accelerometer scales (and their register bit settings) are:
CCastrop1012 2:55ab1dcffe0c 309 // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs (11).
CCastrop1012 2:55ab1dcffe0c 310 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
CCastrop1012 2:55ab1dcffe0c 311 case AFS_2G:
CCastrop1012 2:55ab1dcffe0c 312 aRes = 2.0/32768.0;
CCastrop1012 2:55ab1dcffe0c 313 break;
CCastrop1012 2:55ab1dcffe0c 314 case AFS_4G:
CCastrop1012 2:55ab1dcffe0c 315 aRes = 4.0/32768.0;
CCastrop1012 2:55ab1dcffe0c 316 break;
CCastrop1012 2:55ab1dcffe0c 317 case AFS_8G:
CCastrop1012 2:55ab1dcffe0c 318 aRes = 8.0/32768.0;
CCastrop1012 2:55ab1dcffe0c 319 break;
CCastrop1012 2:55ab1dcffe0c 320 case AFS_16G:
CCastrop1012 2:55ab1dcffe0c 321 aRes = 16.0/32768.0;
CCastrop1012 2:55ab1dcffe0c 322 break;
CCastrop1012 2:55ab1dcffe0c 323 }
CCastrop1012 2:55ab1dcffe0c 324 }
ruevs 0:2315cd1878a1 325
ruevs 0:2315cd1878a1 326
CCastrop1012 2:55ab1dcffe0c 327 void readAccelData(int16_t * destination)
CCastrop1012 2:55ab1dcffe0c 328 {
CCastrop1012 2:55ab1dcffe0c 329 uint8_t rawData[6]; // x/y/z accel register data stored here
CCastrop1012 2:55ab1dcffe0c 330 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
CCastrop1012 2:55ab1dcffe0c 331 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
CCastrop1012 2:55ab1dcffe0c 332 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
CCastrop1012 2:55ab1dcffe0c 333 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
CCastrop1012 2:55ab1dcffe0c 334 }
ruevs 0:2315cd1878a1 335
CCastrop1012 2:55ab1dcffe0c 336 void readGyroData(int16_t * destination)
CCastrop1012 2:55ab1dcffe0c 337 {
CCastrop1012 2:55ab1dcffe0c 338 uint8_t rawData[6]; // x/y/z gyro register data stored here
CCastrop1012 2:55ab1dcffe0c 339 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
CCastrop1012 2:55ab1dcffe0c 340 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
CCastrop1012 2:55ab1dcffe0c 341 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
CCastrop1012 2:55ab1dcffe0c 342 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
CCastrop1012 2:55ab1dcffe0c 343 }
CCastrop1012 2:55ab1dcffe0c 344
CCastrop1012 2:55ab1dcffe0c 345 void readMagData(int16_t * destination)
CCastrop1012 2:55ab1dcffe0c 346 {
CCastrop1012 2:55ab1dcffe0c 347 uint8_t rawData[7]; // x/y/z gyro register data, ST2 register stored here, must read ST2 at end of data acquisition
CCastrop1012 2:55ab1dcffe0c 348 if(readByte(AK8963_ADDRESS, AK8963_ST1) & 0x01) { // wait for magnetometer data ready bit to be set
CCastrop1012 2:55ab1dcffe0c 349 readBytes(AK8963_ADDRESS, AK8963_XOUT_L, 7, &rawData[0]); // Read the six raw data and ST2 registers sequentially into data array
CCastrop1012 2:55ab1dcffe0c 350 uint8_t c = rawData[6]; // End data read by reading ST2 register
CCastrop1012 2:55ab1dcffe0c 351 if(!(c & 0x08)) { // Check if magnetic sensor overflow set, if not then report data
CCastrop1012 2:55ab1dcffe0c 352 destination[0] = (int16_t)(((int16_t)rawData[1] << 8) | rawData[0]); // Turn the MSB and LSB into a signed 16-bit value
CCastrop1012 2:55ab1dcffe0c 353 destination[1] = (int16_t)(((int16_t)rawData[3] << 8) | rawData[2]) ; // Data stored as little Endian
CCastrop1012 2:55ab1dcffe0c 354 destination[2] = (int16_t)(((int16_t)rawData[5] << 8) | rawData[4]) ;
CCastrop1012 2:55ab1dcffe0c 355 }
CCastrop1012 2:55ab1dcffe0c 356 }
CCastrop1012 2:55ab1dcffe0c 357 }
ruevs 0:2315cd1878a1 358
CCastrop1012 2:55ab1dcffe0c 359 int16_t readTempData()
CCastrop1012 2:55ab1dcffe0c 360 {
CCastrop1012 2:55ab1dcffe0c 361 uint8_t rawData[2]; // x/y/z gyro register data stored here
CCastrop1012 2:55ab1dcffe0c 362 readBytes(MPU9250_ADDRESS, TEMP_OUT_H, 2, &rawData[0]); // Read the two raw data registers sequentially into data array
CCastrop1012 2:55ab1dcffe0c 363 return (int16_t)(((int16_t)rawData[0]) << 8 | rawData[1]) ; // Turn the MSB and LSB into a 16-bit value
CCastrop1012 2:55ab1dcffe0c 364 }
ruevs 0:2315cd1878a1 365
ruevs 0:2315cd1878a1 366
CCastrop1012 2:55ab1dcffe0c 367 void resetMPU9250() {
CCastrop1012 2:55ab1dcffe0c 368 // reset device
CCastrop1012 2:55ab1dcffe0c 369 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
CCastrop1012 2:55ab1dcffe0c 370 wait(0.1);
CCastrop1012 2:55ab1dcffe0c 371 }
CCastrop1012 2:55ab1dcffe0c 372
CCastrop1012 2:55ab1dcffe0c 373 void initAK8963(float * destination)
CCastrop1012 2:55ab1dcffe0c 374 {
CCastrop1012 2:55ab1dcffe0c 375 // First extract the factory calibration for each magnetometer axis
CCastrop1012 2:55ab1dcffe0c 376 uint8_t rawData[3]; // x/y/z gyro calibration data stored here
CCastrop1012 2:55ab1dcffe0c 377 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
CCastrop1012 2:55ab1dcffe0c 378 wait(0.01);
CCastrop1012 2:55ab1dcffe0c 379 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x0F); // Enter Fuse ROM access mode
CCastrop1012 2:55ab1dcffe0c 380 wait(0.01);
CCastrop1012 2:55ab1dcffe0c 381 readBytes(AK8963_ADDRESS, AK8963_ASAX, 3, &rawData[0]); // Read the x-, y-, and z-axis calibration values
CCastrop1012 2:55ab1dcffe0c 382 destination[0] = (float)(rawData[0] - 128)/256.0f + 1.0f; // Return x-axis sensitivity adjustment values, etc.
CCastrop1012 2:55ab1dcffe0c 383 destination[1] = (float)(rawData[1] - 128)/256.0f + 1.0f;
CCastrop1012 2:55ab1dcffe0c 384 destination[2] = (float)(rawData[2] - 128)/256.0f + 1.0f;
CCastrop1012 2:55ab1dcffe0c 385 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
CCastrop1012 2:55ab1dcffe0c 386 wait(0.01);
CCastrop1012 2:55ab1dcffe0c 387 // Configure the magnetometer for continuous read and highest resolution
CCastrop1012 2:55ab1dcffe0c 388 // set Mscale bit 4 to 1 (0) to enable 16 (14) bit resolution in CNTL register,
CCastrop1012 2:55ab1dcffe0c 389 // and enable continuous mode data acquisition Mmode (bits [3:0]), 0010 for 8 Hz and 0110 for 100 Hz sample rates
CCastrop1012 2:55ab1dcffe0c 390 writeByte(AK8963_ADDRESS, AK8963_CNTL, Mscale << 4 | Mmode); // Set magnetometer data resolution and sample ODR
CCastrop1012 2:55ab1dcffe0c 391 wait(0.01);
CCastrop1012 2:55ab1dcffe0c 392 }
ruevs 0:2315cd1878a1 393
ruevs 0:2315cd1878a1 394
CCastrop1012 2:55ab1dcffe0c 395 void initMPU9250()
CCastrop1012 2:55ab1dcffe0c 396 {
CCastrop1012 2:55ab1dcffe0c 397 // Initialize MPU9250 device
CCastrop1012 2:55ab1dcffe0c 398 // wake up device
CCastrop1012 2:55ab1dcffe0c 399 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors
CCastrop1012 2:55ab1dcffe0c 400 wait(0.1); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt
CCastrop1012 2:55ab1dcffe0c 401
CCastrop1012 2:55ab1dcffe0c 402 // get stable time source
CCastrop1012 2:55ab1dcffe0c 403 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01); // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
CCastrop1012 2:55ab1dcffe0c 404
CCastrop1012 2:55ab1dcffe0c 405 // Configure Gyro and Accelerometer
CCastrop1012 2:55ab1dcffe0c 406 // Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively;
CCastrop1012 2:55ab1dcffe0c 407 // DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both
CCastrop1012 2:55ab1dcffe0c 408 // Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate
CCastrop1012 2:55ab1dcffe0c 409 writeByte(MPU9250_ADDRESS, CONFIG, 0x03);
CCastrop1012 2:55ab1dcffe0c 410
CCastrop1012 2:55ab1dcffe0c 411 // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV)
CCastrop1012 2:55ab1dcffe0c 412 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x04); // Use a 200 Hz rate; the same rate set in CONFIG above
CCastrop1012 2:55ab1dcffe0c 413
CCastrop1012 2:55ab1dcffe0c 414 // Set gyroscope full scale range
CCastrop1012 2:55ab1dcffe0c 415 // Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3
CCastrop1012 2:55ab1dcffe0c 416 uint8_t c = readByte(MPU9250_ADDRESS, GYRO_CONFIG);
CCastrop1012 2:55ab1dcffe0c 417 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
CCastrop1012 2:55ab1dcffe0c 418 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
CCastrop1012 2:55ab1dcffe0c 419 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c | Gscale << 3); // Set full scale range for the gyro
ruevs 0:2315cd1878a1 420
CCastrop1012 2:55ab1dcffe0c 421 // Set accelerometer configuration
CCastrop1012 2:55ab1dcffe0c 422 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG);
CCastrop1012 2:55ab1dcffe0c 423 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
CCastrop1012 2:55ab1dcffe0c 424 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
CCastrop1012 2:55ab1dcffe0c 425 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c | Ascale << 3); // Set full scale range for the accelerometer
CCastrop1012 2:55ab1dcffe0c 426
CCastrop1012 2:55ab1dcffe0c 427 // Set accelerometer sample rate configuration
CCastrop1012 2:55ab1dcffe0c 428 // It is possible to get a 4 kHz sample rate from the accelerometer by choosing 1 for
CCastrop1012 2:55ab1dcffe0c 429 // accel_fchoice_b bit [3]; in this case the bandwidth is 1.13 kHz
CCastrop1012 2:55ab1dcffe0c 430 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG2);
CCastrop1012 2:55ab1dcffe0c 431 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c & ~0x0F); // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0])
CCastrop1012 2:55ab1dcffe0c 432 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c | 0x03); // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz
ruevs 0:2315cd1878a1 433
CCastrop1012 2:55ab1dcffe0c 434 // The accelerometer, gyro, and thermometer are set to 1 kHz sample rates,
CCastrop1012 2:55ab1dcffe0c 435 // but all these rates are further reduced by a factor of 5 to 200 Hz because of the SMPLRT_DIV setting
CCastrop1012 2:55ab1dcffe0c 436
CCastrop1012 2:55ab1dcffe0c 437 // Configure Interrupts and Bypass Enable
CCastrop1012 2:55ab1dcffe0c 438 // Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips
CCastrop1012 2:55ab1dcffe0c 439 // can join the I2C bus and all can be controlled by the Arduino as master
CCastrop1012 2:55ab1dcffe0c 440 writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x22);
CCastrop1012 2:55ab1dcffe0c 441 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt
CCastrop1012 2:55ab1dcffe0c 442 }
CCastrop1012 2:55ab1dcffe0c 443
CCastrop1012 2:55ab1dcffe0c 444 // Function which accumulates gyro and accelerometer data after device initialization. It calculates the average
CCastrop1012 2:55ab1dcffe0c 445 // of the at-rest readings and then loads the resulting offsets into accelerometer and gyro bias registers.
CCastrop1012 2:55ab1dcffe0c 446 void calibrateMPU9250(float * dest1, float * dest2)
CCastrop1012 2:55ab1dcffe0c 447 {
CCastrop1012 2:55ab1dcffe0c 448 uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data
CCastrop1012 2:55ab1dcffe0c 449 uint16_t ii, packet_count, fifo_count;
CCastrop1012 2:55ab1dcffe0c 450 int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
ruevs 0:2315cd1878a1 451
CCastrop1012 2:55ab1dcffe0c 452 // reset device, reset all registers, clear gyro and accelerometer bias registers
CCastrop1012 2:55ab1dcffe0c 453 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
CCastrop1012 2:55ab1dcffe0c 454 wait(0.1);
CCastrop1012 2:55ab1dcffe0c 455
CCastrop1012 2:55ab1dcffe0c 456 // get stable time source
CCastrop1012 2:55ab1dcffe0c 457 // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
CCastrop1012 2:55ab1dcffe0c 458 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01);
CCastrop1012 2:55ab1dcffe0c 459 writeByte(MPU9250_ADDRESS, PWR_MGMT_2, 0x00);
CCastrop1012 2:55ab1dcffe0c 460 wait(0.2);
ruevs 0:2315cd1878a1 461
CCastrop1012 2:55ab1dcffe0c 462 // Configure device for bias calculation
CCastrop1012 2:55ab1dcffe0c 463 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts
CCastrop1012 2:55ab1dcffe0c 464 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable FIFO
CCastrop1012 2:55ab1dcffe0c 465 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source
CCastrop1012 2:55ab1dcffe0c 466 writeByte(MPU9250_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master
CCastrop1012 2:55ab1dcffe0c 467 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes
CCastrop1012 2:55ab1dcffe0c 468 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP
CCastrop1012 2:55ab1dcffe0c 469 wait(0.015);
ruevs 0:2315cd1878a1 470
CCastrop1012 2:55ab1dcffe0c 471 // Configure MPU9250 gyro and accelerometer for bias calculation
CCastrop1012 2:55ab1dcffe0c 472 writeByte(MPU9250_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz
CCastrop1012 2:55ab1dcffe0c 473 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz
CCastrop1012 2:55ab1dcffe0c 474 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity
CCastrop1012 2:55ab1dcffe0c 475 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity
CCastrop1012 2:55ab1dcffe0c 476
CCastrop1012 2:55ab1dcffe0c 477 uint16_t gyrosensitivity = 131; // = 131 LSB/degrees/sec
CCastrop1012 2:55ab1dcffe0c 478 uint16_t accelsensitivity = 16384; // = 16384 LSB/g
CCastrop1012 2:55ab1dcffe0c 479
CCastrop1012 2:55ab1dcffe0c 480 // Configure FIFO to capture accelerometer and gyro data for bias calculation
CCastrop1012 2:55ab1dcffe0c 481 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x40); // Enable FIFO
CCastrop1012 2:55ab1dcffe0c 482 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9250)
CCastrop1012 2:55ab1dcffe0c 483 wait(0.04); // accumulate 40 samples in 80 milliseconds = 480 bytes
CCastrop1012 2:55ab1dcffe0c 484
CCastrop1012 2:55ab1dcffe0c 485 // At end of sample accumulation, turn off FIFO sensor read
CCastrop1012 2:55ab1dcffe0c 486 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO
CCastrop1012 2:55ab1dcffe0c 487 readBytes(MPU9250_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count
CCastrop1012 2:55ab1dcffe0c 488 fifo_count = ((uint16_t)data[0] << 8) | data[1];
CCastrop1012 2:55ab1dcffe0c 489 packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging
CCastrop1012 2:55ab1dcffe0c 490
CCastrop1012 2:55ab1dcffe0c 491 for (ii = 0; ii < packet_count; ii++) {
CCastrop1012 2:55ab1dcffe0c 492 int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0};
CCastrop1012 2:55ab1dcffe0c 493 readBytes(MPU9250_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging
CCastrop1012 2:55ab1dcffe0c 494 accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO
CCastrop1012 2:55ab1dcffe0c 495 accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ;
CCastrop1012 2:55ab1dcffe0c 496 accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ;
CCastrop1012 2:55ab1dcffe0c 497 gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ;
CCastrop1012 2:55ab1dcffe0c 498 gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ;
CCastrop1012 2:55ab1dcffe0c 499 gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ;
CCastrop1012 2:55ab1dcffe0c 500
CCastrop1012 2:55ab1dcffe0c 501 accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases
CCastrop1012 2:55ab1dcffe0c 502 accel_bias[1] += (int32_t) accel_temp[1];
CCastrop1012 2:55ab1dcffe0c 503 accel_bias[2] += (int32_t) accel_temp[2];
CCastrop1012 2:55ab1dcffe0c 504 gyro_bias[0] += (int32_t) gyro_temp[0];
CCastrop1012 2:55ab1dcffe0c 505 gyro_bias[1] += (int32_t) gyro_temp[1];
CCastrop1012 2:55ab1dcffe0c 506 gyro_bias[2] += (int32_t) gyro_temp[2];
CCastrop1012 2:55ab1dcffe0c 507
CCastrop1012 2:55ab1dcffe0c 508 }
CCastrop1012 2:55ab1dcffe0c 509 accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases
CCastrop1012 2:55ab1dcffe0c 510 accel_bias[1] /= (int32_t) packet_count;
CCastrop1012 2:55ab1dcffe0c 511 accel_bias[2] /= (int32_t) packet_count;
CCastrop1012 2:55ab1dcffe0c 512 gyro_bias[0] /= (int32_t) packet_count;
CCastrop1012 2:55ab1dcffe0c 513 gyro_bias[1] /= (int32_t) packet_count;
CCastrop1012 2:55ab1dcffe0c 514 gyro_bias[2] /= (int32_t) packet_count;
CCastrop1012 2:55ab1dcffe0c 515
CCastrop1012 2:55ab1dcffe0c 516 if(accel_bias[2] > 0L) {accel_bias[2] -= (int32_t) accelsensitivity;} // Remove gravity from the z-axis accelerometer bias calculation
CCastrop1012 2:55ab1dcffe0c 517 else {accel_bias[2] += (int32_t) accelsensitivity;}
CCastrop1012 2:55ab1dcffe0c 518
CCastrop1012 2:55ab1dcffe0c 519 // Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup
CCastrop1012 2:55ab1dcffe0c 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
CCastrop1012 2:55ab1dcffe0c 521 data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
CCastrop1012 2:55ab1dcffe0c 522 data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF;
CCastrop1012 2:55ab1dcffe0c 523 data[3] = (-gyro_bias[1]/4) & 0xFF;
CCastrop1012 2:55ab1dcffe0c 524 data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF;
CCastrop1012 2:55ab1dcffe0c 525 data[5] = (-gyro_bias[2]/4) & 0xFF;
CCastrop1012 2:55ab1dcffe0c 526
CCastrop1012 2:55ab1dcffe0c 527 /// Push gyro biases to hardware registers
CCastrop1012 2:55ab1dcffe0c 528 /* writeByte(MPU9250_ADDRESS, XG_OFFSET_H, data[0]);
CCastrop1012 2:55ab1dcffe0c 529 writeByte(MPU9250_ADDRESS, XG_OFFSET_L, data[1]);
CCastrop1012 2:55ab1dcffe0c 530 writeByte(MPU9250_ADDRESS, YG_OFFSET_H, data[2]);
CCastrop1012 2:55ab1dcffe0c 531 writeByte(MPU9250_ADDRESS, YG_OFFSET_L, data[3]);
CCastrop1012 2:55ab1dcffe0c 532 writeByte(MPU9250_ADDRESS, ZG_OFFSET_H, data[4]);
CCastrop1012 2:55ab1dcffe0c 533 writeByte(MPU9250_ADDRESS, ZG_OFFSET_L, data[5]);
CCastrop1012 2:55ab1dcffe0c 534 */
CCastrop1012 2:55ab1dcffe0c 535 dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction
CCastrop1012 2:55ab1dcffe0c 536 dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity;
CCastrop1012 2:55ab1dcffe0c 537 dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity;
CCastrop1012 2:55ab1dcffe0c 538
CCastrop1012 2:55ab1dcffe0c 539 // Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain
CCastrop1012 2:55ab1dcffe0c 540 // factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold
CCastrop1012 2:55ab1dcffe0c 541 // non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature
CCastrop1012 2:55ab1dcffe0c 542 // compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that
CCastrop1012 2:55ab1dcffe0c 543 // the accelerometer biases calculated above must be divided by 8.
CCastrop1012 2:55ab1dcffe0c 544
CCastrop1012 2:55ab1dcffe0c 545 int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases
CCastrop1012 2:55ab1dcffe0c 546 readBytes(MPU9250_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values
CCastrop1012 2:55ab1dcffe0c 547 accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1];
CCastrop1012 2:55ab1dcffe0c 548 readBytes(MPU9250_ADDRESS, YA_OFFSET_H, 2, &data[0]);
CCastrop1012 2:55ab1dcffe0c 549 accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1];
CCastrop1012 2:55ab1dcffe0c 550 readBytes(MPU9250_ADDRESS, ZA_OFFSET_H, 2, &data[0]);
CCastrop1012 2:55ab1dcffe0c 551 accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1];
ruevs 0:2315cd1878a1 552
CCastrop1012 2:55ab1dcffe0c 553 uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers
CCastrop1012 2:55ab1dcffe0c 554 uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis
CCastrop1012 2:55ab1dcffe0c 555
CCastrop1012 2:55ab1dcffe0c 556 for(ii = 0; ii < 3; ii++) {
CCastrop1012 2:55ab1dcffe0c 557 if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit
CCastrop1012 2:55ab1dcffe0c 558 }
ruevs 0:2315cd1878a1 559
CCastrop1012 2:55ab1dcffe0c 560 // Construct total accelerometer bias, including calculated average accelerometer bias from above
CCastrop1012 2:55ab1dcffe0c 561 accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale)
CCastrop1012 2:55ab1dcffe0c 562 accel_bias_reg[1] -= (accel_bias[1]/8);
CCastrop1012 2:55ab1dcffe0c 563 accel_bias_reg[2] -= (accel_bias[2]/8);
ruevs 0:2315cd1878a1 564
CCastrop1012 2:55ab1dcffe0c 565 data[0] = (accel_bias_reg[0] >> 8) & 0xFF;
CCastrop1012 2:55ab1dcffe0c 566 data[1] = (accel_bias_reg[0]) & 0xFF;
CCastrop1012 2:55ab1dcffe0c 567 data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers
CCastrop1012 2:55ab1dcffe0c 568 data[2] = (accel_bias_reg[1] >> 8) & 0xFF;
CCastrop1012 2:55ab1dcffe0c 569 data[3] = (accel_bias_reg[1]) & 0xFF;
CCastrop1012 2:55ab1dcffe0c 570 data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers
CCastrop1012 2:55ab1dcffe0c 571 data[4] = (accel_bias_reg[2] >> 8) & 0xFF;
CCastrop1012 2:55ab1dcffe0c 572 data[5] = (accel_bias_reg[2]) & 0xFF;
CCastrop1012 2:55ab1dcffe0c 573 data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers
CCastrop1012 2:55ab1dcffe0c 574
CCastrop1012 2:55ab1dcffe0c 575 // Apparently this is not working for the acceleration biases in the MPU-9250
CCastrop1012 2:55ab1dcffe0c 576 // Are we handling the temperature correction bit properly?
CCastrop1012 2:55ab1dcffe0c 577 // Push accelerometer biases to hardware registers
CCastrop1012 2:55ab1dcffe0c 578 /* writeByte(MPU9250_ADDRESS, XA_OFFSET_H, data[0]);
CCastrop1012 2:55ab1dcffe0c 579 writeByte(MPU9250_ADDRESS, XA_OFFSET_L, data[1]);
CCastrop1012 2:55ab1dcffe0c 580 writeByte(MPU9250_ADDRESS, YA_OFFSET_H, data[2]);
CCastrop1012 2:55ab1dcffe0c 581 writeByte(MPU9250_ADDRESS, YA_OFFSET_L, data[3]);
CCastrop1012 2:55ab1dcffe0c 582 writeByte(MPU9250_ADDRESS, ZA_OFFSET_H, data[4]);
CCastrop1012 2:55ab1dcffe0c 583 writeByte(MPU9250_ADDRESS, ZA_OFFSET_L, data[5]);
CCastrop1012 2:55ab1dcffe0c 584 */
CCastrop1012 2:55ab1dcffe0c 585 // Output scaled accelerometer biases for manual subtraction in the main program
CCastrop1012 2:55ab1dcffe0c 586 dest2[0] = (float)accel_bias[0]/(float)accelsensitivity;
CCastrop1012 2:55ab1dcffe0c 587 dest2[1] = (float)accel_bias[1]/(float)accelsensitivity;
CCastrop1012 2:55ab1dcffe0c 588 dest2[2] = (float)accel_bias[2]/(float)accelsensitivity;
CCastrop1012 2:55ab1dcffe0c 589 }
ruevs 0:2315cd1878a1 590
ruevs 0:2315cd1878a1 591
CCastrop1012 2:55ab1dcffe0c 592 // Accelerometer and gyroscope self test; check calibration wrt factory settings
CCastrop1012 2:55ab1dcffe0c 593 void MPU9250SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass
CCastrop1012 2:55ab1dcffe0c 594 {
CCastrop1012 2:55ab1dcffe0c 595 uint8_t rawData[6] = {0, 0, 0, 0, 0, 0};
CCastrop1012 2:55ab1dcffe0c 596 uint8_t selfTest[6];
CCastrop1012 2:55ab1dcffe0c 597 int16_t gAvg[3], aAvg[3], aSTAvg[3], gSTAvg[3];
CCastrop1012 2:55ab1dcffe0c 598 float factoryTrim[6];
CCastrop1012 2:55ab1dcffe0c 599 uint8_t FS = 0;
CCastrop1012 2:55ab1dcffe0c 600
CCastrop1012 2:55ab1dcffe0c 601 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz
CCastrop1012 2:55ab1dcffe0c 602 writeByte(MPU9250_ADDRESS, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz
CCastrop1012 2:55ab1dcffe0c 603 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 1<<FS); // Set full scale range for the gyro to 250 dps
CCastrop1012 2:55ab1dcffe0c 604 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz
CCastrop1012 2:55ab1dcffe0c 605 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 1<<FS); // Set full scale range for the accelerometer to 2 g
CCastrop1012 2:55ab1dcffe0c 606
CCastrop1012 2:55ab1dcffe0c 607 for( int ii = 0; ii < 200; ii++) { // get average current values of gyro and acclerometer
CCastrop1012 2:55ab1dcffe0c 608
CCastrop1012 2:55ab1dcffe0c 609 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
CCastrop1012 2:55ab1dcffe0c 610 aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
CCastrop1012 2:55ab1dcffe0c 611 aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
CCastrop1012 2:55ab1dcffe0c 612 aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
CCastrop1012 2:55ab1dcffe0c 613
CCastrop1012 2:55ab1dcffe0c 614 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
CCastrop1012 2:55ab1dcffe0c 615 gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
CCastrop1012 2:55ab1dcffe0c 616 gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
CCastrop1012 2:55ab1dcffe0c 617 gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
CCastrop1012 2:55ab1dcffe0c 618 }
CCastrop1012 2:55ab1dcffe0c 619
CCastrop1012 2:55ab1dcffe0c 620 for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average current readings
CCastrop1012 2:55ab1dcffe0c 621 aAvg[ii] /= 200;
CCastrop1012 2:55ab1dcffe0c 622 gAvg[ii] /= 200;
CCastrop1012 2:55ab1dcffe0c 623 }
CCastrop1012 2:55ab1dcffe0c 624
CCastrop1012 2:55ab1dcffe0c 625 // Configure the accelerometer for self-test
CCastrop1012 2:55ab1dcffe0c 626 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g
CCastrop1012 2:55ab1dcffe0c 627 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
CCastrop1012 2:55ab1dcffe0c 628 wait_ms(25); // Delay a while to let the device stabilize
ruevs 0:2315cd1878a1 629
CCastrop1012 2:55ab1dcffe0c 630 for( int ii = 0; ii < 200; ii++) { // get average self-test values of gyro and acclerometer
CCastrop1012 2:55ab1dcffe0c 631
CCastrop1012 2:55ab1dcffe0c 632 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
CCastrop1012 2:55ab1dcffe0c 633 aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
CCastrop1012 2:55ab1dcffe0c 634 aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
CCastrop1012 2:55ab1dcffe0c 635 aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
CCastrop1012 2:55ab1dcffe0c 636
CCastrop1012 2:55ab1dcffe0c 637 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
CCastrop1012 2:55ab1dcffe0c 638 gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
CCastrop1012 2:55ab1dcffe0c 639 gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
CCastrop1012 2:55ab1dcffe0c 640 gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
CCastrop1012 2:55ab1dcffe0c 641 }
CCastrop1012 2:55ab1dcffe0c 642
CCastrop1012 2:55ab1dcffe0c 643 for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average self-test readings
CCastrop1012 2:55ab1dcffe0c 644 aSTAvg[ii] /= 200;
CCastrop1012 2:55ab1dcffe0c 645 gSTAvg[ii] /= 200;
CCastrop1012 2:55ab1dcffe0c 646 }
CCastrop1012 2:55ab1dcffe0c 647
CCastrop1012 2:55ab1dcffe0c 648 // Configure the gyro and accelerometer for normal operation
CCastrop1012 2:55ab1dcffe0c 649 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00);
CCastrop1012 2:55ab1dcffe0c 650 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00);
CCastrop1012 2:55ab1dcffe0c 651 wait_ms(25); // Delay a while to let the device stabilize
CCastrop1012 2:55ab1dcffe0c 652
CCastrop1012 2:55ab1dcffe0c 653 // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg
CCastrop1012 2:55ab1dcffe0c 654 selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results
CCastrop1012 2:55ab1dcffe0c 655 selfTest[1] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_ACCEL); // Y-axis accel self-test results
CCastrop1012 2:55ab1dcffe0c 656 selfTest[2] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_ACCEL); // Z-axis accel self-test results
CCastrop1012 2:55ab1dcffe0c 657 selfTest[3] = readByte(MPU9250_ADDRESS, SELF_TEST_X_GYRO); // X-axis gyro self-test results
CCastrop1012 2:55ab1dcffe0c 658 selfTest[4] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_GYRO); // Y-axis gyro self-test results
CCastrop1012 2:55ab1dcffe0c 659 selfTest[5] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_GYRO); // Z-axis gyro self-test results
CCastrop1012 2:55ab1dcffe0c 660
CCastrop1012 2:55ab1dcffe0c 661 // Retrieve factory self-test value from self-test code reads
CCastrop1012 2:55ab1dcffe0c 662 factoryTrim[0] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation
CCastrop1012 2:55ab1dcffe0c 663 factoryTrim[1] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation
CCastrop1012 2:55ab1dcffe0c 664 factoryTrim[2] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation
CCastrop1012 2:55ab1dcffe0c 665 factoryTrim[3] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation
CCastrop1012 2:55ab1dcffe0c 666 factoryTrim[4] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation
CCastrop1012 2:55ab1dcffe0c 667 factoryTrim[5] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation
CCastrop1012 2:55ab1dcffe0c 668
CCastrop1012 2:55ab1dcffe0c 669 // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response
CCastrop1012 2:55ab1dcffe0c 670 // To get percent, must multiply by 100
CCastrop1012 2:55ab1dcffe0c 671 for (int i = 0; i < 3; i++) {
CCastrop1012 2:55ab1dcffe0c 672 destination[i] = 100.0*((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i]; // Report percent differences
CCastrop1012 2:55ab1dcffe0c 673 destination[i+3] = 100.0*((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3]; // Report percent differences
CCastrop1012 2:55ab1dcffe0c 674 }
CCastrop1012 2:55ab1dcffe0c 675
CCastrop1012 2:55ab1dcffe0c 676 }
CCastrop1012 2:55ab1dcffe0c 677
CCastrop1012 2:55ab1dcffe0c 678
ruevs 0:2315cd1878a1 679
ruevs 0:2315cd1878a1 680 // Implementation of Sebastian Madgwick's "...efficient orientation filter for... inertial/magnetic sensor arrays"
ruevs 0:2315cd1878a1 681 // (see http://www.x-io.co.uk/category/open-source/ for examples and more details)
ruevs 0:2315cd1878a1 682 // which fuses acceleration, rotation rate, and magnetic moments to produce a quaternion-based estimate of absolute
ruevs 0:2315cd1878a1 683 // device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc.
ruevs 0:2315cd1878a1 684 // The performance of the orientation filter is at least as good as conventional Kalman-based filtering algorithms
ruevs 0:2315cd1878a1 685 // but is much less computationally intensive---it can be performed on a 3.3 V Pro Mini operating at 8 MHz!
ruevs 0:2315cd1878a1 686 void MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
ruevs 0:2315cd1878a1 687 {
ruevs 0:2315cd1878a1 688 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
ruevs 0:2315cd1878a1 689 float norm;
ruevs 0:2315cd1878a1 690 float hx, hy, _2bx, _2bz;
ruevs 0:2315cd1878a1 691 float s1, s2, s3, s4;
ruevs 0:2315cd1878a1 692 float qDot1, qDot2, qDot3, qDot4;
ruevs 0:2315cd1878a1 693
ruevs 0:2315cd1878a1 694 // Auxiliary variables to avoid repeated arithmetic
ruevs 0:2315cd1878a1 695 float _2q1mx;
ruevs 0:2315cd1878a1 696 float _2q1my;
ruevs 0:2315cd1878a1 697 float _2q1mz;
ruevs 0:2315cd1878a1 698 float _2q2mx;
ruevs 0:2315cd1878a1 699 float _4bx;
ruevs 0:2315cd1878a1 700 float _4bz;
ruevs 0:2315cd1878a1 701 float _2q1 = 2.0f * q1;
ruevs 0:2315cd1878a1 702 float _2q2 = 2.0f * q2;
ruevs 0:2315cd1878a1 703 float _2q3 = 2.0f * q3;
ruevs 0:2315cd1878a1 704 float _2q4 = 2.0f * q4;
ruevs 0:2315cd1878a1 705 float _2q1q3 = 2.0f * q1 * q3;
ruevs 0:2315cd1878a1 706 float _2q3q4 = 2.0f * q3 * q4;
ruevs 0:2315cd1878a1 707 float q1q1 = q1 * q1;
ruevs 0:2315cd1878a1 708 float q1q2 = q1 * q2;
ruevs 0:2315cd1878a1 709 float q1q3 = q1 * q3;
ruevs 0:2315cd1878a1 710 float q1q4 = q1 * q4;
ruevs 0:2315cd1878a1 711 float q2q2 = q2 * q2;
ruevs 0:2315cd1878a1 712 float q2q3 = q2 * q3;
ruevs 0:2315cd1878a1 713 float q2q4 = q2 * q4;
ruevs 0:2315cd1878a1 714 float q3q3 = q3 * q3;
ruevs 0:2315cd1878a1 715 float q3q4 = q3 * q4;
ruevs 0:2315cd1878a1 716 float q4q4 = q4 * q4;
ruevs 0:2315cd1878a1 717
ruevs 0:2315cd1878a1 718 // Normalise accelerometer measurement
ruevs 0:2315cd1878a1 719 norm = sqrt(ax * ax + ay * ay + az * az);
ruevs 0:2315cd1878a1 720 if (norm == 0.0f) return; // handle NaN
ruevs 0:2315cd1878a1 721 norm = 1.0f/norm;
ruevs 0:2315cd1878a1 722 ax *= norm;
ruevs 0:2315cd1878a1 723 ay *= norm;
ruevs 0:2315cd1878a1 724 az *= norm;
ruevs 0:2315cd1878a1 725
ruevs 0:2315cd1878a1 726 // Normalise magnetometer measurement
ruevs 0:2315cd1878a1 727 norm = sqrt(mx * mx + my * my + mz * mz);
ruevs 0:2315cd1878a1 728 if (norm == 0.0f) return; // handle NaN
ruevs 0:2315cd1878a1 729 norm = 1.0f/norm;
ruevs 0:2315cd1878a1 730 mx *= norm;
ruevs 0:2315cd1878a1 731 my *= norm;
ruevs 0:2315cd1878a1 732 mz *= norm;
ruevs 0:2315cd1878a1 733
ruevs 0:2315cd1878a1 734 // Reference direction of Earth's magnetic field
ruevs 0:2315cd1878a1 735 _2q1mx = 2.0f * q1 * mx;
ruevs 0:2315cd1878a1 736 _2q1my = 2.0f * q1 * my;
ruevs 0:2315cd1878a1 737 _2q1mz = 2.0f * q1 * mz;
ruevs 0:2315cd1878a1 738 _2q2mx = 2.0f * q2 * mx;
ruevs 0:2315cd1878a1 739 hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4;
ruevs 0:2315cd1878a1 740 hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4;
ruevs 0:2315cd1878a1 741 _2bx = sqrt(hx * hx + hy * hy);
ruevs 0:2315cd1878a1 742 _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4;
ruevs 0:2315cd1878a1 743 _4bx = 2.0f * _2bx;
ruevs 0:2315cd1878a1 744 _4bz = 2.0f * _2bz;
ruevs 0:2315cd1878a1 745
ruevs 0:2315cd1878a1 746 // Gradient decent algorithm corrective step
ruevs 0:2315cd1878a1 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);
ruevs 0:2315cd1878a1 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);
ruevs 0:2315cd1878a1 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);
ruevs 0:2315cd1878a1 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);
ruevs 0:2315cd1878a1 751 norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4); // normalise step magnitude
ruevs 0:2315cd1878a1 752 norm = 1.0f/norm;
ruevs 0:2315cd1878a1 753 s1 *= norm;
ruevs 0:2315cd1878a1 754 s2 *= norm;
ruevs 0:2315cd1878a1 755 s3 *= norm;
ruevs 0:2315cd1878a1 756 s4 *= norm;
ruevs 0:2315cd1878a1 757
ruevs 0:2315cd1878a1 758 // Compute rate of change of quaternion
ruevs 0:2315cd1878a1 759 qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1;
ruevs 0:2315cd1878a1 760 qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2;
ruevs 0:2315cd1878a1 761 qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3;
ruevs 0:2315cd1878a1 762 qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4;
ruevs 0:2315cd1878a1 763
ruevs 0:2315cd1878a1 764 // Integrate to yield quaternion
ruevs 0:2315cd1878a1 765 q1 += qDot1 * deltat;
ruevs 0:2315cd1878a1 766 q2 += qDot2 * deltat;
ruevs 0:2315cd1878a1 767 q3 += qDot3 * deltat;
ruevs 0:2315cd1878a1 768 q4 += qDot4 * deltat;
ruevs 0:2315cd1878a1 769 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion
ruevs 0:2315cd1878a1 770 norm = 1.0f/norm;
ruevs 0:2315cd1878a1 771 q[0] = q1 * norm;
ruevs 0:2315cd1878a1 772 q[1] = q2 * norm;
ruevs 0:2315cd1878a1 773 q[2] = q3 * norm;
ruevs 0:2315cd1878a1 774 q[3] = q4 * norm;
ruevs 0:2315cd1878a1 775
ruevs 0:2315cd1878a1 776 }
ruevs 0:2315cd1878a1 777
ruevs 0:2315cd1878a1 778
ruevs 0:2315cd1878a1 779
ruevs 0:2315cd1878a1 780 // Similar to Madgwick scheme but uses proportional and integral filtering on the error between estimated reference vectors and
ruevs 0:2315cd1878a1 781 // measured ones.
ruevs 0:2315cd1878a1 782 void MahonyQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
ruevs 0:2315cd1878a1 783 {
ruevs 0:2315cd1878a1 784 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
ruevs 0:2315cd1878a1 785 float norm;
ruevs 0:2315cd1878a1 786 float hx, hy, bx, bz;
ruevs 0:2315cd1878a1 787 float vx, vy, vz, wx, wy, wz;
ruevs 0:2315cd1878a1 788 float ex, ey, ez;
ruevs 0:2315cd1878a1 789 float pa, pb, pc;
ruevs 0:2315cd1878a1 790
ruevs 0:2315cd1878a1 791 // Auxiliary variables to avoid repeated arithmetic
ruevs 0:2315cd1878a1 792 float q1q1 = q1 * q1;
ruevs 0:2315cd1878a1 793 float q1q2 = q1 * q2;
ruevs 0:2315cd1878a1 794 float q1q3 = q1 * q3;
ruevs 0:2315cd1878a1 795 float q1q4 = q1 * q4;
ruevs 0:2315cd1878a1 796 float q2q2 = q2 * q2;
ruevs 0:2315cd1878a1 797 float q2q3 = q2 * q3;
ruevs 0:2315cd1878a1 798 float q2q4 = q2 * q4;
ruevs 0:2315cd1878a1 799 float q3q3 = q3 * q3;
ruevs 0:2315cd1878a1 800 float q3q4 = q3 * q4;
ruevs 0:2315cd1878a1 801 float q4q4 = q4 * q4;
ruevs 0:2315cd1878a1 802
ruevs 0:2315cd1878a1 803 // Normalise accelerometer measurement
ruevs 0:2315cd1878a1 804 norm = sqrt(ax * ax + ay * ay + az * az);
ruevs 0:2315cd1878a1 805 if (norm == 0.0f) return; // handle NaN
ruevs 0:2315cd1878a1 806 norm = 1.0f / norm; // use reciprocal for division
ruevs 0:2315cd1878a1 807 ax *= norm;
ruevs 0:2315cd1878a1 808 ay *= norm;
ruevs 0:2315cd1878a1 809 az *= norm;
ruevs 0:2315cd1878a1 810
ruevs 0:2315cd1878a1 811 // Normalise magnetometer measurement
ruevs 0:2315cd1878a1 812 norm = sqrt(mx * mx + my * my + mz * mz);
ruevs 0:2315cd1878a1 813 if (norm == 0.0f) return; // handle NaN
ruevs 0:2315cd1878a1 814 norm = 1.0f / norm; // use reciprocal for division
ruevs 0:2315cd1878a1 815 mx *= norm;
ruevs 0:2315cd1878a1 816 my *= norm;
ruevs 0:2315cd1878a1 817 mz *= norm;
ruevs 0:2315cd1878a1 818
ruevs 0:2315cd1878a1 819 // Reference direction of Earth's magnetic field
ruevs 0:2315cd1878a1 820 hx = 2.0f * mx * (0.5f - q3q3 - q4q4) + 2.0f * my * (q2q3 - q1q4) + 2.0f * mz * (q2q4 + q1q3);
ruevs 0:2315cd1878a1 821 hy = 2.0f * mx * (q2q3 + q1q4) + 2.0f * my * (0.5f - q2q2 - q4q4) + 2.0f * mz * (q3q4 - q1q2);
ruevs 0:2315cd1878a1 822 bx = sqrt((hx * hx) + (hy * hy));
ruevs 0:2315cd1878a1 823 bz = 2.0f * mx * (q2q4 - q1q3) + 2.0f * my * (q3q4 + q1q2) + 2.0f * mz * (0.5f - q2q2 - q3q3);
ruevs 0:2315cd1878a1 824
ruevs 0:2315cd1878a1 825 // Estimated direction of gravity and magnetic field
ruevs 0:2315cd1878a1 826 vx = 2.0f * (q2q4 - q1q3);
ruevs 0:2315cd1878a1 827 vy = 2.0f * (q1q2 + q3q4);
ruevs 0:2315cd1878a1 828 vz = q1q1 - q2q2 - q3q3 + q4q4;
ruevs 0:2315cd1878a1 829 wx = 2.0f * bx * (0.5f - q3q3 - q4q4) + 2.0f * bz * (q2q4 - q1q3);
ruevs 0:2315cd1878a1 830 wy = 2.0f * bx * (q2q3 - q1q4) + 2.0f * bz * (q1q2 + q3q4);
ruevs 0:2315cd1878a1 831 wz = 2.0f * bx * (q1q3 + q2q4) + 2.0f * bz * (0.5f - q2q2 - q3q3);
ruevs 0:2315cd1878a1 832
ruevs 0:2315cd1878a1 833 // Error is cross product between estimated direction and measured direction of gravity
ruevs 0:2315cd1878a1 834 ex = (ay * vz - az * vy) + (my * wz - mz * wy);
ruevs 0:2315cd1878a1 835 ey = (az * vx - ax * vz) + (mz * wx - mx * wz);
ruevs 0:2315cd1878a1 836 ez = (ax * vy - ay * vx) + (mx * wy - my * wx);
ruevs 0:2315cd1878a1 837 if (Ki > 0.0f)
ruevs 0:2315cd1878a1 838 {
ruevs 0:2315cd1878a1 839 eInt[0] += ex; // accumulate integral error
ruevs 0:2315cd1878a1 840 eInt[1] += ey;
ruevs 0:2315cd1878a1 841 eInt[2] += ez;
ruevs 0:2315cd1878a1 842 }
ruevs 0:2315cd1878a1 843 else
ruevs 0:2315cd1878a1 844 {
ruevs 0:2315cd1878a1 845 eInt[0] = 0.0f; // prevent integral wind up
ruevs 0:2315cd1878a1 846 eInt[1] = 0.0f;
ruevs 0:2315cd1878a1 847 eInt[2] = 0.0f;
ruevs 0:2315cd1878a1 848 }
ruevs 0:2315cd1878a1 849
ruevs 0:2315cd1878a1 850 // Apply feedback terms
ruevs 0:2315cd1878a1 851 gx = gx + Kp * ex + Ki * eInt[0];
ruevs 0:2315cd1878a1 852 gy = gy + Kp * ey + Ki * eInt[1];
ruevs 0:2315cd1878a1 853 gz = gz + Kp * ez + Ki * eInt[2];
ruevs 0:2315cd1878a1 854
ruevs 0:2315cd1878a1 855 // Integrate rate of change of quaternion
ruevs 0:2315cd1878a1 856 pa = q2;
ruevs 0:2315cd1878a1 857 pb = q3;
ruevs 0:2315cd1878a1 858 pc = q4;
ruevs 0:2315cd1878a1 859 q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * deltat);
ruevs 0:2315cd1878a1 860 q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * deltat);
ruevs 0:2315cd1878a1 861 q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * deltat);
ruevs 0:2315cd1878a1 862 q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * deltat);
ruevs 0:2315cd1878a1 863
ruevs 0:2315cd1878a1 864 // Normalise quaternion
ruevs 0:2315cd1878a1 865 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);
ruevs 0:2315cd1878a1 866 norm = 1.0f / norm;
ruevs 0:2315cd1878a1 867 q[0] = q1 * norm;
ruevs 0:2315cd1878a1 868 q[1] = q2 * norm;
ruevs 0:2315cd1878a1 869 q[2] = q3 * norm;
ruevs 0:2315cd1878a1 870 q[3] = q4 * norm;
ruevs 0:2315cd1878a1 871
ruevs 0:2315cd1878a1 872 }
ruevs 0:2315cd1878a1 873 };
ruevs 0:2315cd1878a1 874 #endif