Bradley Kohler / Mbed 2 deprecated Pedometer_Smooth

MPU6050 Pedometer

Dependencies:   mbed

Pedometer using the MPU6050

MPU6050.h@0:93289d2d6bce, 2017-11-21 (annotated)

Committer:
kohlerba
Date:
Tue Nov 21 20:37:39 2017 +0000
Revision:
0:93289d2d6bce
A pedometer using the MAX30100 6DOF module

Who changed what in which revision?

UserRevisionLine numberNew contents of line
kohlerba 0:93289d2d6bce 1 #ifndef MPU6050_H
kohlerba 0:93289d2d6bce 2 #define MPU6050_H
kohlerba 0:93289d2d6bce 3
kohlerba 0:93289d2d6bce 4 #include "mbed.h"
kohlerba 0:93289d2d6bce 5 #include "math.h"
kohlerba 0:93289d2d6bce 6
kohlerba 0:93289d2d6bce 7 // Define registers per MPU6050, Register Map and Descriptions, Rev 4.2, 08/19/2013 6 DOF Motion sensor fusion device
kohlerba 0:93289d2d6bce 8 // Invensense Inc., www.invensense.com
kohlerba 0:93289d2d6bce 9 // See also MPU-6050 Register Map and Descriptions, Revision 4.0, RM-MPU-6050A-00, 9/12/2012 for registers not listed in
kohlerba 0:93289d2d6bce 10 // above document; the MPU6050 and MPU 9150 are virtually identical but the latter has an on-board magnetic sensor
kohlerba 0:93289d2d6bce 11 //
kohlerba 0:93289d2d6bce 12 #define XGOFFS_TC 0x00 // Bit 7 PWR_MODE, bits 6:1 XG_OFFS_TC, bit 0 OTP_BNK_VLD
kohlerba 0:93289d2d6bce 13 #define YGOFFS_TC 0x01
kohlerba 0:93289d2d6bce 14 #define ZGOFFS_TC 0x02
kohlerba 0:93289d2d6bce 15 #define X_FINE_GAIN 0x03 // [7:0] fine gain
kohlerba 0:93289d2d6bce 16 #define Y_FINE_GAIN 0x04
kohlerba 0:93289d2d6bce 17 #define Z_FINE_GAIN 0x05
kohlerba 0:93289d2d6bce 18 #define XA_OFFSET_H 0x06 // User-defined trim values for accelerometer
kohlerba 0:93289d2d6bce 19 #define XA_OFFSET_L_TC 0x07
kohlerba 0:93289d2d6bce 20 #define YA_OFFSET_H 0x08
kohlerba 0:93289d2d6bce 21 #define YA_OFFSET_L_TC 0x09
kohlerba 0:93289d2d6bce 22 #define ZA_OFFSET_H 0x0A
kohlerba 0:93289d2d6bce 23 #define ZA_OFFSET_L_TC 0x0B
kohlerba 0:93289d2d6bce 24 #define SELF_TEST_X 0x0D
kohlerba 0:93289d2d6bce 25 #define SELF_TEST_Y 0x0E
kohlerba 0:93289d2d6bce 26 #define SELF_TEST_Z 0x0F
kohlerba 0:93289d2d6bce 27 #define SELF_TEST_A 0x10
kohlerba 0:93289d2d6bce 28 #define XG_OFFS_USRH 0x13 // User-defined trim values for gyroscope; supported in MPU-6050?
kohlerba 0:93289d2d6bce 29 #define XG_OFFS_USRL 0x14
kohlerba 0:93289d2d6bce 30 #define YG_OFFS_USRH 0x15
kohlerba 0:93289d2d6bce 31 #define YG_OFFS_USRL 0x16
kohlerba 0:93289d2d6bce 32 #define ZG_OFFS_USRH 0x17
kohlerba 0:93289d2d6bce 33 #define ZG_OFFS_USRL 0x18
kohlerba 0:93289d2d6bce 34 #define SMPLRT_DIV 0x19
kohlerba 0:93289d2d6bce 35 #define CONFIG 0x1A
kohlerba 0:93289d2d6bce 36 #define GYRO_CONFIG 0x1B
kohlerba 0:93289d2d6bce 37 #define ACCEL_CONFIG 0x1C
kohlerba 0:93289d2d6bce 38 #define FF_THR 0x1D // Free-fall
kohlerba 0:93289d2d6bce 39 #define FF_DUR 0x1E // Free-fall
kohlerba 0:93289d2d6bce 40 #define MOT_THR 0x1F // Motion detection threshold bits [7:0]
kohlerba 0:93289d2d6bce 41 #define MOT_DUR 0x20 // Duration counter threshold for motion interrupt generation, 1 kHz rate, LSB = 1 ms
kohlerba 0:93289d2d6bce 42 #define ZMOT_THR 0x21 // Zero-motion detection threshold bits [7:0]
kohlerba 0:93289d2d6bce 43 #define ZRMOT_DUR 0x22 // Duration counter threshold for zero motion interrupt generation, 16 Hz rate, LSB = 64 ms
kohlerba 0:93289d2d6bce 44 #define FIFO_EN 0x23
kohlerba 0:93289d2d6bce 45 #define I2C_MST_CTRL 0x24
kohlerba 0:93289d2d6bce 46 #define I2C_SLV0_ADDR 0x25
kohlerba 0:93289d2d6bce 47 #define I2C_SLV0_REG 0x26
kohlerba 0:93289d2d6bce 48 #define I2C_SLV0_CTRL 0x27
kohlerba 0:93289d2d6bce 49 #define I2C_SLV1_ADDR 0x28
kohlerba 0:93289d2d6bce 50 #define I2C_SLV1_REG 0x29
kohlerba 0:93289d2d6bce 51 #define I2C_SLV1_CTRL 0x2A
kohlerba 0:93289d2d6bce 52 #define I2C_SLV2_ADDR 0x2B
kohlerba 0:93289d2d6bce 53 #define I2C_SLV2_REG 0x2C
kohlerba 0:93289d2d6bce 54 #define I2C_SLV2_CTRL 0x2D
kohlerba 0:93289d2d6bce 55 #define I2C_SLV3_ADDR 0x2E
kohlerba 0:93289d2d6bce 56 #define I2C_SLV3_REG 0x2F
kohlerba 0:93289d2d6bce 57 #define I2C_SLV3_CTRL 0x30
kohlerba 0:93289d2d6bce 58 #define I2C_SLV4_ADDR 0x31
kohlerba 0:93289d2d6bce 59 #define I2C_SLV4_REG 0x32
kohlerba 0:93289d2d6bce 60 #define I2C_SLV4_DO 0x33
kohlerba 0:93289d2d6bce 61 #define I2C_SLV4_CTRL 0x34
kohlerba 0:93289d2d6bce 62 #define I2C_SLV4_DI 0x35
kohlerba 0:93289d2d6bce 63 #define I2C_MST_STATUS 0x36
kohlerba 0:93289d2d6bce 64 #define INT_PIN_CFG 0x37
kohlerba 0:93289d2d6bce 65 #define INT_ENABLE 0x38
kohlerba 0:93289d2d6bce 66 #define DMP_INT_STATUS 0x39 // Check DMP interrupt
kohlerba 0:93289d2d6bce 67 #define INT_STATUS 0x3A
kohlerba 0:93289d2d6bce 68 #define ACCEL_XOUT_H 0x3B
kohlerba 0:93289d2d6bce 69 #define ACCEL_XOUT_L 0x3C
kohlerba 0:93289d2d6bce 70 #define ACCEL_YOUT_H 0x3D
kohlerba 0:93289d2d6bce 71 #define ACCEL_YOUT_L 0x3E
kohlerba 0:93289d2d6bce 72 #define ACCEL_ZOUT_H 0x3F
kohlerba 0:93289d2d6bce 73 #define ACCEL_ZOUT_L 0x40
kohlerba 0:93289d2d6bce 74 #define TEMP_OUT_H 0x41
kohlerba 0:93289d2d6bce 75 #define TEMP_OUT_L 0x42
kohlerba 0:93289d2d6bce 76 #define GYRO_XOUT_H 0x43
kohlerba 0:93289d2d6bce 77 #define GYRO_XOUT_L 0x44
kohlerba 0:93289d2d6bce 78 #define GYRO_YOUT_H 0x45
kohlerba 0:93289d2d6bce 79 #define GYRO_YOUT_L 0x46
kohlerba 0:93289d2d6bce 80 #define GYRO_ZOUT_H 0x47
kohlerba 0:93289d2d6bce 81 #define GYRO_ZOUT_L 0x48
kohlerba 0:93289d2d6bce 82 #define EXT_SENS_DATA_00 0x49
kohlerba 0:93289d2d6bce 83 #define EXT_SENS_DATA_01 0x4A
kohlerba 0:93289d2d6bce 84 #define EXT_SENS_DATA_02 0x4B
kohlerba 0:93289d2d6bce 85 #define EXT_SENS_DATA_03 0x4C
kohlerba 0:93289d2d6bce 86 #define EXT_SENS_DATA_04 0x4D
kohlerba 0:93289d2d6bce 87 #define EXT_SENS_DATA_05 0x4E
kohlerba 0:93289d2d6bce 88 #define EXT_SENS_DATA_06 0x4F
kohlerba 0:93289d2d6bce 89 #define EXT_SENS_DATA_07 0x50
kohlerba 0:93289d2d6bce 90 #define EXT_SENS_DATA_08 0x51
kohlerba 0:93289d2d6bce 91 #define EXT_SENS_DATA_09 0x52
kohlerba 0:93289d2d6bce 92 #define EXT_SENS_DATA_10 0x53
kohlerba 0:93289d2d6bce 93 #define EXT_SENS_DATA_11 0x54
kohlerba 0:93289d2d6bce 94 #define EXT_SENS_DATA_12 0x55
kohlerba 0:93289d2d6bce 95 #define EXT_SENS_DATA_13 0x56
kohlerba 0:93289d2d6bce 96 #define EXT_SENS_DATA_14 0x57
kohlerba 0:93289d2d6bce 97 #define EXT_SENS_DATA_15 0x58
kohlerba 0:93289d2d6bce 98 #define EXT_SENS_DATA_16 0x59
kohlerba 0:93289d2d6bce 99 #define EXT_SENS_DATA_17 0x5A
kohlerba 0:93289d2d6bce 100 #define EXT_SENS_DATA_18 0x5B
kohlerba 0:93289d2d6bce 101 #define EXT_SENS_DATA_19 0x5C
kohlerba 0:93289d2d6bce 102 #define EXT_SENS_DATA_20 0x5D
kohlerba 0:93289d2d6bce 103 #define EXT_SENS_DATA_21 0x5E
kohlerba 0:93289d2d6bce 104 #define EXT_SENS_DATA_22 0x5F
kohlerba 0:93289d2d6bce 105 #define EXT_SENS_DATA_23 0x60
kohlerba 0:93289d2d6bce 106 #define MOT_DETECT_STATUS 0x61
kohlerba 0:93289d2d6bce 107 #define I2C_SLV0_DO 0x63
kohlerba 0:93289d2d6bce 108 #define I2C_SLV1_DO 0x64
kohlerba 0:93289d2d6bce 109 #define I2C_SLV2_DO 0x65
kohlerba 0:93289d2d6bce 110 #define I2C_SLV3_DO 0x66
kohlerba 0:93289d2d6bce 111 #define I2C_MST_DELAY_CTRL 0x67
kohlerba 0:93289d2d6bce 112 #define SIGNAL_PATH_RESET 0x68
kohlerba 0:93289d2d6bce 113 #define MOT_DETECT_CTRL 0x69
kohlerba 0:93289d2d6bce 114 #define USER_CTRL 0x6A // Bit 7 enable DMP, bit 3 reset DMP
kohlerba 0:93289d2d6bce 115 #define PWR_MGMT_1 0x6B // Device defaults to the SLEEP mode
kohlerba 0:93289d2d6bce 116 #define PWR_MGMT_2 0x6C
kohlerba 0:93289d2d6bce 117 #define DMP_BANK 0x6D // Activates a specific bank in the DMP
kohlerba 0:93289d2d6bce 118 #define DMP_RW_PNT 0x6E // Set read/write pointer to a specific start address in specified DMP bank
kohlerba 0:93289d2d6bce 119 #define DMP_REG 0x6F // Register in DMP from which to read or to which to write
kohlerba 0:93289d2d6bce 120 #define DMP_REG_1 0x70
kohlerba 0:93289d2d6bce 121 #define DMP_REG_2 0x71
kohlerba 0:93289d2d6bce 122 #define FIFO_COUNTH 0x72
kohlerba 0:93289d2d6bce 123 #define FIFO_COUNTL 0x73
kohlerba 0:93289d2d6bce 124 #define FIFO_R_W 0x74
kohlerba 0:93289d2d6bce 125 #define WHO_AM_I_MPU6050 0x75 // Should return 0x68
kohlerba 0:93289d2d6bce 126
kohlerba 0:93289d2d6bce 127 // Using the GY-521 breakout board, I set ADO to 0 by grounding through a 4k7 resistor
kohlerba 0:93289d2d6bce 128 // Seven-bit device address is 110100 for ADO = 0 and 110101 for ADO = 1
kohlerba 0:93289d2d6bce 129 #define ADO 0
kohlerba 0:93289d2d6bce 130 #if ADO
kohlerba 0:93289d2d6bce 131 #define MPU6050_ADDRESS 0x69<<1 // Device address when ADO = 1
kohlerba 0:93289d2d6bce 132 #else
kohlerba 0:93289d2d6bce 133 #define MPU6050_ADDRESS 0x68<<1 // Device address when ADO = 0
kohlerba 0:93289d2d6bce 134 #endif
kohlerba 0:93289d2d6bce 135
kohlerba 0:93289d2d6bce 136 // Set initial input parameters
kohlerba 0:93289d2d6bce 137 enum Ascale {
kohlerba 0:93289d2d6bce 138 AFS_2G = 0,
kohlerba 0:93289d2d6bce 139 AFS_4G,
kohlerba 0:93289d2d6bce 140 AFS_8G,
kohlerba 0:93289d2d6bce 141 AFS_16G
kohlerba 0:93289d2d6bce 142 };
kohlerba 0:93289d2d6bce 143
kohlerba 0:93289d2d6bce 144 enum Gscale {
kohlerba 0:93289d2d6bce 145 GFS_250DPS = 0,
kohlerba 0:93289d2d6bce 146 GFS_500DPS,
kohlerba 0:93289d2d6bce 147 GFS_1000DPS,
kohlerba 0:93289d2d6bce 148 GFS_2000DPS
kohlerba 0:93289d2d6bce 149 };
kohlerba 0:93289d2d6bce 150
kohlerba 0:93289d2d6bce 151 // Specify sensor full scale
kohlerba 0:93289d2d6bce 152 int Gscale = GFS_250DPS;
kohlerba 0:93289d2d6bce 153 int Ascale = AFS_2G;
kohlerba 0:93289d2d6bce 154
kohlerba 0:93289d2d6bce 155 //Set up I2C, (SDA,SCL)
kohlerba 0:93289d2d6bce 156 I2C i2c(I2C_SDA, I2C_SCL);
kohlerba 0:93289d2d6bce 157
kohlerba 0:93289d2d6bce 158 DigitalOut myled(LED1);
kohlerba 0:93289d2d6bce 159
kohlerba 0:93289d2d6bce 160 float aRes, gRes; // scale resolutions per LSB for the sensors
kohlerba 0:93289d2d6bce 161
kohlerba 0:93289d2d6bce 162 // Pin definitions
kohlerba 0:93289d2d6bce 163 int intPin = 12; // These can be changed, 2 and 3 are the Arduinos ext int pins
kohlerba 0:93289d2d6bce 164
kohlerba 0:93289d2d6bce 165 int16_t accelCount[3]; // Stores the 16-bit signed accelerometer sensor output
kohlerba 0:93289d2d6bce 166 float ax, ay, az; // Stores the real accel value in g's
kohlerba 0:93289d2d6bce 167 int16_t gyroCount[3]; // Stores the 16-bit signed gyro sensor output
kohlerba 0:93289d2d6bce 168 float gx, gy, gz; // Stores the real gyro value in degrees per seconds
kohlerba 0:93289d2d6bce 169 float gyroBias[3] = {0, 0, 0}, accelBias[3] = {0, 0, 0}; // Bias corrections for gyro and accelerometer
kohlerba 0:93289d2d6bce 170 int16_t tempCount; // Stores the real internal chip temperature in degrees Celsius
kohlerba 0:93289d2d6bce 171 float temperature;
kohlerba 0:93289d2d6bce 172 float SelfTest[6];
kohlerba 0:93289d2d6bce 173
kohlerba 0:93289d2d6bce 174 int delt_t = 0; // used to control display output rate
kohlerba 0:93289d2d6bce 175 int count = 0; // used to control display output rate
kohlerba 0:93289d2d6bce 176
kohlerba 0:93289d2d6bce 177 // parameters for 6 DoF sensor fusion calculations
kohlerba 0:93289d2d6bce 178 float PI = 3.14159265358979323846f;
kohlerba 0:93289d2d6bce 179 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
kohlerba 0:93289d2d6bce 180 float beta = sqrt(3.0f / 4.0f) * GyroMeasError; // compute beta
kohlerba 0:93289d2d6bce 181 float GyroMeasDrift = PI * (1.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
kohlerba 0:93289d2d6bce 182 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
kohlerba 0:93289d2d6bce 183 float pitch, yaw, roll;
kohlerba 0:93289d2d6bce 184 float deltat = 0.0f; // integration interval for both filter schemes
kohlerba 0:93289d2d6bce 185 int lastUpdate = 0, firstUpdate = 0, Now = 0; // used to calculate integration interval // used to calculate integration interval
kohlerba 0:93289d2d6bce 186 float q[4] = {1.0f, 0.0f, 0.0f, 0.0f}; // vector to hold quaternion
kohlerba 0:93289d2d6bce 187
kohlerba 0:93289d2d6bce 188 class MPU6050 {
kohlerba 0:93289d2d6bce 189
kohlerba 0:93289d2d6bce 190 protected:
kohlerba 0:93289d2d6bce 191
kohlerba 0:93289d2d6bce 192 public:
kohlerba 0:93289d2d6bce 193 //===================================================================================================================
kohlerba 0:93289d2d6bce 194 //====== Set of useful function to access acceleratio, gyroscope, and temperature data
kohlerba 0:93289d2d6bce 195 //===================================================================================================================
kohlerba 0:93289d2d6bce 196
kohlerba 0:93289d2d6bce 197 void writeByte(uint8_t address, uint8_t subAddress, uint8_t data)
kohlerba 0:93289d2d6bce 198 {
kohlerba 0:93289d2d6bce 199 char data_write[2];
kohlerba 0:93289d2d6bce 200 data_write[0] = subAddress;
kohlerba 0:93289d2d6bce 201 data_write[1] = data;
kohlerba 0:93289d2d6bce 202 i2c.write(address, data_write, 2, 0);
kohlerba 0:93289d2d6bce 203 }
kohlerba 0:93289d2d6bce 204
kohlerba 0:93289d2d6bce 205 char readByte(uint8_t address, uint8_t subAddress)
kohlerba 0:93289d2d6bce 206 {
kohlerba 0:93289d2d6bce 207 char data[1]; // `data` will store the register data
kohlerba 0:93289d2d6bce 208 char data_write[1];
kohlerba 0:93289d2d6bce 209 data_write[0] = subAddress;
kohlerba 0:93289d2d6bce 210 i2c.write(address, data_write, 1, 1); // no stop
kohlerba 0:93289d2d6bce 211 i2c.read(address, data, 1, 0);
kohlerba 0:93289d2d6bce 212 return data[0];
kohlerba 0:93289d2d6bce 213 }
kohlerba 0:93289d2d6bce 214
kohlerba 0:93289d2d6bce 215 void readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest)
kohlerba 0:93289d2d6bce 216 {
kohlerba 0:93289d2d6bce 217 char data[14];
kohlerba 0:93289d2d6bce 218 char data_write[1];
kohlerba 0:93289d2d6bce 219 data_write[0] = subAddress;
kohlerba 0:93289d2d6bce 220 i2c.write(address, data_write, 1, 1); // no stop
kohlerba 0:93289d2d6bce 221 i2c.read(address, data, count, 0);
kohlerba 0:93289d2d6bce 222 for(int ii = 0; ii < count; ii++) {
kohlerba 0:93289d2d6bce 223 dest[ii] = data[ii];
kohlerba 0:93289d2d6bce 224 }
kohlerba 0:93289d2d6bce 225 }
kohlerba 0:93289d2d6bce 226
kohlerba 0:93289d2d6bce 227
kohlerba 0:93289d2d6bce 228 void getGres() {
kohlerba 0:93289d2d6bce 229 switch (Gscale)
kohlerba 0:93289d2d6bce 230 {
kohlerba 0:93289d2d6bce 231 // Possible gyro scales (and their register bit settings) are:
kohlerba 0:93289d2d6bce 232 // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS (11).
kohlerba 0:93289d2d6bce 233 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
kohlerba 0:93289d2d6bce 234 case GFS_250DPS:
kohlerba 0:93289d2d6bce 235 gRes = 250.0/32768.0;
kohlerba 0:93289d2d6bce 236 break;
kohlerba 0:93289d2d6bce 237 case GFS_500DPS:
kohlerba 0:93289d2d6bce 238 gRes = 500.0/32768.0;
kohlerba 0:93289d2d6bce 239 break;
kohlerba 0:93289d2d6bce 240 case GFS_1000DPS:
kohlerba 0:93289d2d6bce 241 gRes = 1000.0/32768.0;
kohlerba 0:93289d2d6bce 242 break;
kohlerba 0:93289d2d6bce 243 case GFS_2000DPS:
kohlerba 0:93289d2d6bce 244 gRes = 2000.0/32768.0;
kohlerba 0:93289d2d6bce 245 break;
kohlerba 0:93289d2d6bce 246 }
kohlerba 0:93289d2d6bce 247 }
kohlerba 0:93289d2d6bce 248
kohlerba 0:93289d2d6bce 249 void getAres() {
kohlerba 0:93289d2d6bce 250 switch (Ascale)
kohlerba 0:93289d2d6bce 251 {
kohlerba 0:93289d2d6bce 252 // Possible accelerometer scales (and their register bit settings) are:
kohlerba 0:93289d2d6bce 253 // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs (11).
kohlerba 0:93289d2d6bce 254 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
kohlerba 0:93289d2d6bce 255 case AFS_2G:
kohlerba 0:93289d2d6bce 256 aRes = 2.0/32768.0;
kohlerba 0:93289d2d6bce 257 break;
kohlerba 0:93289d2d6bce 258 case AFS_4G:
kohlerba 0:93289d2d6bce 259 aRes = 4.0/32768.0;
kohlerba 0:93289d2d6bce 260 break;
kohlerba 0:93289d2d6bce 261 case AFS_8G:
kohlerba 0:93289d2d6bce 262 aRes = 8.0/32768.0;
kohlerba 0:93289d2d6bce 263 break;
kohlerba 0:93289d2d6bce 264 case AFS_16G:
kohlerba 0:93289d2d6bce 265 aRes = 16.0/32768.0;
kohlerba 0:93289d2d6bce 266 break;
kohlerba 0:93289d2d6bce 267 }
kohlerba 0:93289d2d6bce 268 }
kohlerba 0:93289d2d6bce 269
kohlerba 0:93289d2d6bce 270
kohlerba 0:93289d2d6bce 271 void readAccelData(int16_t * destination)
kohlerba 0:93289d2d6bce 272 {
kohlerba 0:93289d2d6bce 273 uint8_t rawData[6]; // x/y/z accel register data stored here
kohlerba 0:93289d2d6bce 274 readBytes(MPU6050_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
kohlerba 0:93289d2d6bce 275 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
kohlerba 0:93289d2d6bce 276 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
kohlerba 0:93289d2d6bce 277 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
kohlerba 0:93289d2d6bce 278 }
kohlerba 0:93289d2d6bce 279
kohlerba 0:93289d2d6bce 280 void readGyroData(int16_t * destination)
kohlerba 0:93289d2d6bce 281 {
kohlerba 0:93289d2d6bce 282 uint8_t rawData[6]; // x/y/z gyro register data stored here
kohlerba 0:93289d2d6bce 283 readBytes(MPU6050_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
kohlerba 0:93289d2d6bce 284 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
kohlerba 0:93289d2d6bce 285 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
kohlerba 0:93289d2d6bce 286 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
kohlerba 0:93289d2d6bce 287 }
kohlerba 0:93289d2d6bce 288
kohlerba 0:93289d2d6bce 289 int16_t readTempData()
kohlerba 0:93289d2d6bce 290 {
kohlerba 0:93289d2d6bce 291 uint8_t rawData[2]; // x/y/z gyro register data stored here
kohlerba 0:93289d2d6bce 292 readBytes(MPU6050_ADDRESS, TEMP_OUT_H, 2, &rawData[0]); // Read the two raw data registers sequentially into data array
kohlerba 0:93289d2d6bce 293 return (int16_t)(((int16_t)rawData[0]) << 8 | rawData[1]) ; // Turn the MSB and LSB into a 16-bit value
kohlerba 0:93289d2d6bce 294 }
kohlerba 0:93289d2d6bce 295
kohlerba 0:93289d2d6bce 296
kohlerba 0:93289d2d6bce 297
kohlerba 0:93289d2d6bce 298 // Configure the motion detection control for low power accelerometer mode
kohlerba 0:93289d2d6bce 299 void LowPowerAccelOnly()
kohlerba 0:93289d2d6bce 300 {
kohlerba 0:93289d2d6bce 301
kohlerba 0:93289d2d6bce 302 // The sensor has a high-pass filter necessary to invoke to allow the sensor motion detection algorithms work properly
kohlerba 0:93289d2d6bce 303 // Motion detection occurs on free-fall (acceleration below a threshold for some time for all axes), motion (acceleration
kohlerba 0:93289d2d6bce 304 // above a threshold for some time on at least one axis), and zero-motion toggle (acceleration on each axis less than a
kohlerba 0:93289d2d6bce 305 // threshold for some time sets this flag, motion above the threshold turns it off). The high-pass filter takes gravity out
kohlerba 0:93289d2d6bce 306 // consideration for these threshold evaluations; otherwise, the flags would be set all the time!
kohlerba 0:93289d2d6bce 307
kohlerba 0:93289d2d6bce 308 uint8_t c = readByte(MPU6050_ADDRESS, PWR_MGMT_1);
kohlerba 0:93289d2d6bce 309 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, c & ~0x30); // Clear sleep and cycle bits [5:6]
kohlerba 0:93289d2d6bce 310 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, c | 0x30); // Set sleep and cycle bits [5:6] to zero to make sure accelerometer is running
kohlerba 0:93289d2d6bce 311
kohlerba 0:93289d2d6bce 312 c = readByte(MPU6050_ADDRESS, PWR_MGMT_2);
kohlerba 0:93289d2d6bce 313 writeByte(MPU6050_ADDRESS, PWR_MGMT_2, c & ~0x38); // Clear standby XA, YA, and ZA bits [3:5]
kohlerba 0:93289d2d6bce 314 writeByte(MPU6050_ADDRESS, PWR_MGMT_2, c | 0x00); // Set XA, YA, and ZA bits [3:5] to zero to make sure accelerometer is running
kohlerba 0:93289d2d6bce 315
kohlerba 0:93289d2d6bce 316 c = readByte(MPU6050_ADDRESS, ACCEL_CONFIG);
kohlerba 0:93289d2d6bce 317 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c & ~0x07); // Clear high-pass filter bits [2:0]
kohlerba 0:93289d2d6bce 318 // Set high-pass filter to 0) reset (disable), 1) 5 Hz, 2) 2.5 Hz, 3) 1.25 Hz, 4) 0.63 Hz, or 7) Hold
kohlerba 0:93289d2d6bce 319 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c | 0x00); // Set ACCEL_HPF to 0; reset mode disbaling high-pass filter
kohlerba 0:93289d2d6bce 320
kohlerba 0:93289d2d6bce 321 c = readByte(MPU6050_ADDRESS, CONFIG);
kohlerba 0:93289d2d6bce 322 writeByte(MPU6050_ADDRESS, CONFIG, c & ~0x07); // Clear low-pass filter bits [2:0]
kohlerba 0:93289d2d6bce 323 writeByte(MPU6050_ADDRESS, CONFIG, c | 0x00); // Set DLPD_CFG to 0; 260 Hz bandwidth, 1 kHz rate
kohlerba 0:93289d2d6bce 324
kohlerba 0:93289d2d6bce 325 c = readByte(MPU6050_ADDRESS, INT_ENABLE);
kohlerba 0:93289d2d6bce 326 writeByte(MPU6050_ADDRESS, INT_ENABLE, c & ~0xFF); // Clear all interrupts
kohlerba 0:93289d2d6bce 327 writeByte(MPU6050_ADDRESS, INT_ENABLE, 0x40); // Enable motion threshold (bits 5) interrupt only
kohlerba 0:93289d2d6bce 328
kohlerba 0:93289d2d6bce 329 // Motion detection interrupt requires the absolute value of any axis to lie above the detection threshold
kohlerba 0:93289d2d6bce 330 // for at least the counter duration
kohlerba 0:93289d2d6bce 331 writeByte(MPU6050_ADDRESS, MOT_THR, 0x80); // Set motion detection to 0.256 g; LSB = 2 mg
kohlerba 0:93289d2d6bce 332 writeByte(MPU6050_ADDRESS, MOT_DUR, 0x01); // Set motion detect duration to 1 ms; LSB is 1 ms @ 1 kHz rate
kohlerba 0:93289d2d6bce 333
kohlerba 0:93289d2d6bce 334 wait(0.1); // Add delay for accumulation of samples
kohlerba 0:93289d2d6bce 335
kohlerba 0:93289d2d6bce 336 c = readByte(MPU6050_ADDRESS, ACCEL_CONFIG);
kohlerba 0:93289d2d6bce 337 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c & ~0x07); // Clear high-pass filter bits [2:0]
kohlerba 0:93289d2d6bce 338 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c | 0x07); // Set ACCEL_HPF to 7; hold the initial accleration value as a referance
kohlerba 0:93289d2d6bce 339
kohlerba 0:93289d2d6bce 340 c = readByte(MPU6050_ADDRESS, PWR_MGMT_2);
kohlerba 0:93289d2d6bce 341 writeByte(MPU6050_ADDRESS, PWR_MGMT_2, c & ~0xC7); // Clear standby XA, YA, and ZA bits [3:5] and LP_WAKE_CTRL bits [6:7]
kohlerba 0:93289d2d6bce 342 writeByte(MPU6050_ADDRESS, PWR_MGMT_2, c | 0x47); // Set wakeup frequency to 5 Hz, and disable XG, YG, and ZG gyros (bits [0:2])
kohlerba 0:93289d2d6bce 343
kohlerba 0:93289d2d6bce 344 c = readByte(MPU6050_ADDRESS, PWR_MGMT_1);
kohlerba 0:93289d2d6bce 345 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, c & ~0x20); // Clear sleep and cycle bit 5
kohlerba 0:93289d2d6bce 346 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, c | 0x20); // Set cycle bit 5 to begin low power accelerometer motion interrupts
kohlerba 0:93289d2d6bce 347
kohlerba 0:93289d2d6bce 348 }
kohlerba 0:93289d2d6bce 349
kohlerba 0:93289d2d6bce 350
kohlerba 0:93289d2d6bce 351 void resetMPU6050() {
kohlerba 0:93289d2d6bce 352 // reset device
kohlerba 0:93289d2d6bce 353 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
kohlerba 0:93289d2d6bce 354 wait(0.1);
kohlerba 0:93289d2d6bce 355 }
kohlerba 0:93289d2d6bce 356
kohlerba 0:93289d2d6bce 357
kohlerba 0:93289d2d6bce 358 void initMPU6050()
kohlerba 0:93289d2d6bce 359 {
kohlerba 0:93289d2d6bce 360 // Initialize MPU6050 device
kohlerba 0:93289d2d6bce 361 // wake up device
kohlerba 0:93289d2d6bce 362 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors
kohlerba 0:93289d2d6bce 363 wait(0.1); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt
kohlerba 0:93289d2d6bce 364
kohlerba 0:93289d2d6bce 365 // get stable time source
kohlerba 0:93289d2d6bce 366 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x01); // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
kohlerba 0:93289d2d6bce 367
kohlerba 0:93289d2d6bce 368 // Configure Gyro and Accelerometer
kohlerba 0:93289d2d6bce 369 // Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively;
kohlerba 0:93289d2d6bce 370 // DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both
kohlerba 0:93289d2d6bce 371 // Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate
kohlerba 0:93289d2d6bce 372 writeByte(MPU6050_ADDRESS, CONFIG, 0x03);
kohlerba 0:93289d2d6bce 373
kohlerba 0:93289d2d6bce 374 // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV)
kohlerba 0:93289d2d6bce 375 writeByte(MPU6050_ADDRESS, SMPLRT_DIV, 0x04); // Use a 200 Hz rate; the same rate set in CONFIG above
kohlerba 0:93289d2d6bce 376
kohlerba 0:93289d2d6bce 377 // Set gyroscope full scale range
kohlerba 0:93289d2d6bce 378 // Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3
kohlerba 0:93289d2d6bce 379 uint8_t c = readByte(MPU6050_ADDRESS, GYRO_CONFIG);
kohlerba 0:93289d2d6bce 380 writeByte(MPU6050_ADDRESS, GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
kohlerba 0:93289d2d6bce 381 writeByte(MPU6050_ADDRESS, GYRO_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
kohlerba 0:93289d2d6bce 382 writeByte(MPU6050_ADDRESS, GYRO_CONFIG, c | Gscale << 3); // Set full scale range for the gyro
kohlerba 0:93289d2d6bce 383
kohlerba 0:93289d2d6bce 384 // Set accelerometer configuration
kohlerba 0:93289d2d6bce 385 c = readByte(MPU6050_ADDRESS, ACCEL_CONFIG);
kohlerba 0:93289d2d6bce 386 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
kohlerba 0:93289d2d6bce 387 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
kohlerba 0:93289d2d6bce 388 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c | Ascale << 3); // Set full scale range for the accelerometer
kohlerba 0:93289d2d6bce 389
kohlerba 0:93289d2d6bce 390 // Configure Interrupts and Bypass Enable
kohlerba 0:93289d2d6bce 391 // Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips
kohlerba 0:93289d2d6bce 392 // can join the I2C bus and all can be controlled by the Arduino as master
kohlerba 0:93289d2d6bce 393 writeByte(MPU6050_ADDRESS, INT_PIN_CFG, 0x22);
kohlerba 0:93289d2d6bce 394 writeByte(MPU6050_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt
kohlerba 0:93289d2d6bce 395 }
kohlerba 0:93289d2d6bce 396
kohlerba 0:93289d2d6bce 397 // Function which accumulates gyro and accelerometer data after device initialization. It calculates the average
kohlerba 0:93289d2d6bce 398 // of the at-rest readings and then loads the resulting offsets into accelerometer and gyro bias registers.
kohlerba 0:93289d2d6bce 399 void calibrateMPU6050(float * dest1, float * dest2)
kohlerba 0:93289d2d6bce 400 {
kohlerba 0:93289d2d6bce 401 uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data
kohlerba 0:93289d2d6bce 402 uint16_t ii, packet_count, fifo_count;
kohlerba 0:93289d2d6bce 403 int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
kohlerba 0:93289d2d6bce 404
kohlerba 0:93289d2d6bce 405 // reset device, reset all registers, clear gyro and accelerometer bias registers
kohlerba 0:93289d2d6bce 406 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
kohlerba 0:93289d2d6bce 407 wait(0.1);
kohlerba 0:93289d2d6bce 408
kohlerba 0:93289d2d6bce 409 // get stable time source
kohlerba 0:93289d2d6bce 410 // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
kohlerba 0:93289d2d6bce 411 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x01);
kohlerba 0:93289d2d6bce 412 writeByte(MPU6050_ADDRESS, PWR_MGMT_2, 0x00);
kohlerba 0:93289d2d6bce 413 wait(0.2);
kohlerba 0:93289d2d6bce 414
kohlerba 0:93289d2d6bce 415 // Configure device for bias calculation
kohlerba 0:93289d2d6bce 416 writeByte(MPU6050_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts
kohlerba 0:93289d2d6bce 417 writeByte(MPU6050_ADDRESS, FIFO_EN, 0x00); // Disable FIFO
kohlerba 0:93289d2d6bce 418 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source
kohlerba 0:93289d2d6bce 419 writeByte(MPU6050_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master
kohlerba 0:93289d2d6bce 420 writeByte(MPU6050_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes
kohlerba 0:93289d2d6bce 421 writeByte(MPU6050_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP
kohlerba 0:93289d2d6bce 422 wait(0.015);
kohlerba 0:93289d2d6bce 423
kohlerba 0:93289d2d6bce 424 // Configure MPU6050 gyro and accelerometer for bias calculation
kohlerba 0:93289d2d6bce 425 writeByte(MPU6050_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz
kohlerba 0:93289d2d6bce 426 writeByte(MPU6050_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz
kohlerba 0:93289d2d6bce 427 writeByte(MPU6050_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity
kohlerba 0:93289d2d6bce 428 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity
kohlerba 0:93289d2d6bce 429
kohlerba 0:93289d2d6bce 430 uint16_t gyrosensitivity = 131; // = 131 LSB/degrees/sec
kohlerba 0:93289d2d6bce 431 uint16_t accelsensitivity = 16384; // = 16384 LSB/g
kohlerba 0:93289d2d6bce 432
kohlerba 0:93289d2d6bce 433 // Configure FIFO to capture accelerometer and gyro data for bias calculation
kohlerba 0:93289d2d6bce 434 writeByte(MPU6050_ADDRESS, USER_CTRL, 0x40); // Enable FIFO
kohlerba 0:93289d2d6bce 435 writeByte(MPU6050_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 1024 bytes in MPU-6050)
kohlerba 0:93289d2d6bce 436 wait(0.08); // accumulate 80 samples in 80 milliseconds = 960 bytes
kohlerba 0:93289d2d6bce 437
kohlerba 0:93289d2d6bce 438 // At end of sample accumulation, turn off FIFO sensor read
kohlerba 0:93289d2d6bce 439 writeByte(MPU6050_ADDRESS, FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO
kohlerba 0:93289d2d6bce 440 readBytes(MPU6050_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count
kohlerba 0:93289d2d6bce 441 fifo_count = ((uint16_t)data[0] << 8) | data[1];
kohlerba 0:93289d2d6bce 442 packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging
kohlerba 0:93289d2d6bce 443
kohlerba 0:93289d2d6bce 444 for (ii = 0; ii < packet_count; ii++) {
kohlerba 0:93289d2d6bce 445 int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0};
kohlerba 0:93289d2d6bce 446 readBytes(MPU6050_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging
kohlerba 0:93289d2d6bce 447 accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO
kohlerba 0:93289d2d6bce 448 accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ;
kohlerba 0:93289d2d6bce 449 accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ;
kohlerba 0:93289d2d6bce 450 gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ;
kohlerba 0:93289d2d6bce 451 gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ;
kohlerba 0:93289d2d6bce 452 gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ;
kohlerba 0:93289d2d6bce 453
kohlerba 0:93289d2d6bce 454 accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases
kohlerba 0:93289d2d6bce 455 accel_bias[1] += (int32_t) accel_temp[1];
kohlerba 0:93289d2d6bce 456 accel_bias[2] += (int32_t) accel_temp[2];
kohlerba 0:93289d2d6bce 457 gyro_bias[0] += (int32_t) gyro_temp[0];
kohlerba 0:93289d2d6bce 458 gyro_bias[1] += (int32_t) gyro_temp[1];
kohlerba 0:93289d2d6bce 459 gyro_bias[2] += (int32_t) gyro_temp[2];
kohlerba 0:93289d2d6bce 460
kohlerba 0:93289d2d6bce 461 }
kohlerba 0:93289d2d6bce 462 accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases
kohlerba 0:93289d2d6bce 463 accel_bias[1] /= (int32_t) packet_count;
kohlerba 0:93289d2d6bce 464 accel_bias[2] /= (int32_t) packet_count;
kohlerba 0:93289d2d6bce 465 gyro_bias[0] /= (int32_t) packet_count;
kohlerba 0:93289d2d6bce 466 gyro_bias[1] /= (int32_t) packet_count;
kohlerba 0:93289d2d6bce 467 gyro_bias[2] /= (int32_t) packet_count;
kohlerba 0:93289d2d6bce 468
kohlerba 0:93289d2d6bce 469 if(accel_bias[2] > 0L) {accel_bias[2] -= (int32_t) accelsensitivity;} // Remove gravity from the z-axis accelerometer bias calculation
kohlerba 0:93289d2d6bce 470 else {accel_bias[2] += (int32_t) accelsensitivity;}
kohlerba 0:93289d2d6bce 471
kohlerba 0:93289d2d6bce 472 // Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup
kohlerba 0:93289d2d6bce 473 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
kohlerba 0:93289d2d6bce 474 data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
kohlerba 0:93289d2d6bce 475 data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF;
kohlerba 0:93289d2d6bce 476 data[3] = (-gyro_bias[1]/4) & 0xFF;
kohlerba 0:93289d2d6bce 477 data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF;
kohlerba 0:93289d2d6bce 478 data[5] = (-gyro_bias[2]/4) & 0xFF;
kohlerba 0:93289d2d6bce 479
kohlerba 0:93289d2d6bce 480 // Push gyro biases to hardware registers
kohlerba 0:93289d2d6bce 481 writeByte(MPU6050_ADDRESS, XG_OFFS_USRH, data[0]);
kohlerba 0:93289d2d6bce 482 writeByte(MPU6050_ADDRESS, XG_OFFS_USRL, data[1]);
kohlerba 0:93289d2d6bce 483 writeByte(MPU6050_ADDRESS, YG_OFFS_USRH, data[2]);
kohlerba 0:93289d2d6bce 484 writeByte(MPU6050_ADDRESS, YG_OFFS_USRL, data[3]);
kohlerba 0:93289d2d6bce 485 writeByte(MPU6050_ADDRESS, ZG_OFFS_USRH, data[4]);
kohlerba 0:93289d2d6bce 486 writeByte(MPU6050_ADDRESS, ZG_OFFS_USRL, data[5]);
kohlerba 0:93289d2d6bce 487
kohlerba 0:93289d2d6bce 488 dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction
kohlerba 0:93289d2d6bce 489 dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity;
kohlerba 0:93289d2d6bce 490 dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity;
kohlerba 0:93289d2d6bce 491
kohlerba 0:93289d2d6bce 492 // Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain
kohlerba 0:93289d2d6bce 493 // factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold
kohlerba 0:93289d2d6bce 494 // non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature
kohlerba 0:93289d2d6bce 495 // compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that
kohlerba 0:93289d2d6bce 496 // the accelerometer biases calculated above must be divided by 8.
kohlerba 0:93289d2d6bce 497
kohlerba 0:93289d2d6bce 498 int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases
kohlerba 0:93289d2d6bce 499 readBytes(MPU6050_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values
kohlerba 0:93289d2d6bce 500 accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1];
kohlerba 0:93289d2d6bce 501 readBytes(MPU6050_ADDRESS, YA_OFFSET_H, 2, &data[0]);
kohlerba 0:93289d2d6bce 502 accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1];
kohlerba 0:93289d2d6bce 503 readBytes(MPU6050_ADDRESS, ZA_OFFSET_H, 2, &data[0]);
kohlerba 0:93289d2d6bce 504 accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1];
kohlerba 0:93289d2d6bce 505
kohlerba 0:93289d2d6bce 506 uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers
kohlerba 0:93289d2d6bce 507 uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis
kohlerba 0:93289d2d6bce 508
kohlerba 0:93289d2d6bce 509 for(ii = 0; ii < 3; ii++) {
kohlerba 0:93289d2d6bce 510 if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit
kohlerba 0:93289d2d6bce 511 }
kohlerba 0:93289d2d6bce 512
kohlerba 0:93289d2d6bce 513 // Construct total accelerometer bias, including calculated average accelerometer bias from above
kohlerba 0:93289d2d6bce 514 accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale)
kohlerba 0:93289d2d6bce 515 accel_bias_reg[1] -= (accel_bias[1]/8);
kohlerba 0:93289d2d6bce 516 accel_bias_reg[2] -= (accel_bias[2]/8);
kohlerba 0:93289d2d6bce 517
kohlerba 0:93289d2d6bce 518 data[0] = (accel_bias_reg[0] >> 8) & 0xFF;
kohlerba 0:93289d2d6bce 519 data[1] = (accel_bias_reg[0]) & 0xFF;
kohlerba 0:93289d2d6bce 520 data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers
kohlerba 0:93289d2d6bce 521 data[2] = (accel_bias_reg[1] >> 8) & 0xFF;
kohlerba 0:93289d2d6bce 522 data[3] = (accel_bias_reg[1]) & 0xFF;
kohlerba 0:93289d2d6bce 523 data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers
kohlerba 0:93289d2d6bce 524 data[4] = (accel_bias_reg[2] >> 8) & 0xFF;
kohlerba 0:93289d2d6bce 525 data[5] = (accel_bias_reg[2]) & 0xFF;
kohlerba 0:93289d2d6bce 526 data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers
kohlerba 0:93289d2d6bce 527
kohlerba 0:93289d2d6bce 528 // Push accelerometer biases to hardware registers
kohlerba 0:93289d2d6bce 529 // writeByte(MPU6050_ADDRESS, XA_OFFSET_H, data[0]);
kohlerba 0:93289d2d6bce 530 // writeByte(MPU6050_ADDRESS, XA_OFFSET_L_TC, data[1]);
kohlerba 0:93289d2d6bce 531 // writeByte(MPU6050_ADDRESS, YA_OFFSET_H, data[2]);
kohlerba 0:93289d2d6bce 532 // writeByte(MPU6050_ADDRESS, YA_OFFSET_L_TC, data[3]);
kohlerba 0:93289d2d6bce 533 // writeByte(MPU6050_ADDRESS, ZA_OFFSET_H, data[4]);
kohlerba 0:93289d2d6bce 534 // writeByte(MPU6050_ADDRESS, ZA_OFFSET_L_TC, data[5]);
kohlerba 0:93289d2d6bce 535
kohlerba 0:93289d2d6bce 536 // Output scaled accelerometer biases for manual subtraction in the main program
kohlerba 0:93289d2d6bce 537 dest2[0] = (float)accel_bias[0]/(float)accelsensitivity;
kohlerba 0:93289d2d6bce 538 dest2[1] = (float)accel_bias[1]/(float)accelsensitivity;
kohlerba 0:93289d2d6bce 539 dest2[2] = (float)accel_bias[2]/(float)accelsensitivity;
kohlerba 0:93289d2d6bce 540 }
kohlerba 0:93289d2d6bce 541
kohlerba 0:93289d2d6bce 542
kohlerba 0:93289d2d6bce 543 // Accelerometer and gyroscope self test; check calibration wrt factory settings
kohlerba 0:93289d2d6bce 544 void MPU6050SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass
kohlerba 0:93289d2d6bce 545 {
kohlerba 0:93289d2d6bce 546 uint8_t rawData[4] = {0, 0, 0, 0};
kohlerba 0:93289d2d6bce 547 uint8_t selfTest[6];
kohlerba 0:93289d2d6bce 548 float factoryTrim[6];
kohlerba 0:93289d2d6bce 549
kohlerba 0:93289d2d6bce 550 // Configure the accelerometer for self-test
kohlerba 0:93289d2d6bce 551 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, 0xF0); // Enable self test on all three axes and set accelerometer range to +/- 8 g
kohlerba 0:93289d2d6bce 552 writeByte(MPU6050_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
kohlerba 0:93289d2d6bce 553 wait(0.25); // Delay a while to let the device execute the self-test
kohlerba 0:93289d2d6bce 554 rawData[0] = readByte(MPU6050_ADDRESS, SELF_TEST_X); // X-axis self-test results
kohlerba 0:93289d2d6bce 555 rawData[1] = readByte(MPU6050_ADDRESS, SELF_TEST_Y); // Y-axis self-test results
kohlerba 0:93289d2d6bce 556 rawData[2] = readByte(MPU6050_ADDRESS, SELF_TEST_Z); // Z-axis self-test results
kohlerba 0:93289d2d6bce 557 rawData[3] = readByte(MPU6050_ADDRESS, SELF_TEST_A); // Mixed-axis self-test results
kohlerba 0:93289d2d6bce 558 // Extract the acceleration test results first
kohlerba 0:93289d2d6bce 559 selfTest[0] = (rawData[0] >> 3) | (rawData[3] & 0x30) >> 4 ; // XA_TEST result is a five-bit unsigned integer
kohlerba 0:93289d2d6bce 560 selfTest[1] = (rawData[1] >> 3) | (rawData[3] & 0x0C) >> 4 ; // YA_TEST result is a five-bit unsigned integer
kohlerba 0:93289d2d6bce 561 selfTest[2] = (rawData[2] >> 3) | (rawData[3] & 0x03) >> 4 ; // ZA_TEST result is a five-bit unsigned integer
kohlerba 0:93289d2d6bce 562 // Extract the gyration test results first
kohlerba 0:93289d2d6bce 563 selfTest[3] = rawData[0] & 0x1F ; // XG_TEST result is a five-bit unsigned integer
kohlerba 0:93289d2d6bce 564 selfTest[4] = rawData[1] & 0x1F ; // YG_TEST result is a five-bit unsigned integer
kohlerba 0:93289d2d6bce 565 selfTest[5] = rawData[2] & 0x1F ; // ZG_TEST result is a five-bit unsigned integer
kohlerba 0:93289d2d6bce 566 // Process results to allow final comparison with factory set values
kohlerba 0:93289d2d6bce 567 factoryTrim[0] = (4096.0f*0.34f)*(pow( (0.92f/0.34f) , ((selfTest[0] - 1.0f)/30.0f))); // FT[Xa] factory trim calculation
kohlerba 0:93289d2d6bce 568 factoryTrim[1] = (4096.0f*0.34f)*(pow( (0.92f/0.34f) , ((selfTest[1] - 1.0f)/30.0f))); // FT[Ya] factory trim calculation
kohlerba 0:93289d2d6bce 569 factoryTrim[2] = (4096.0f*0.34f)*(pow( (0.92f/0.34f) , ((selfTest[2] - 1.0f)/30.0f))); // FT[Za] factory trim calculation
kohlerba 0:93289d2d6bce 570 factoryTrim[3] = ( 25.0f*131.0f)*(pow( 1.046f , (selfTest[3] - 1.0f) )); // FT[Xg] factory trim calculation
kohlerba 0:93289d2d6bce 571 factoryTrim[4] = (-25.0f*131.0f)*(pow( 1.046f , (selfTest[4] - 1.0f) )); // FT[Yg] factory trim calculation
kohlerba 0:93289d2d6bce 572 factoryTrim[5] = ( 25.0f*131.0f)*(pow( 1.046f , (selfTest[5] - 1.0f) )); // FT[Zg] factory trim calculation
kohlerba 0:93289d2d6bce 573
kohlerba 0:93289d2d6bce 574 // Output self-test results and factory trim calculation if desired
kohlerba 0:93289d2d6bce 575 // Serial.println(selfTest[0]); Serial.println(selfTest[1]); Serial.println(selfTest[2]);
kohlerba 0:93289d2d6bce 576 // Serial.println(selfTest[3]); Serial.println(selfTest[4]); Serial.println(selfTest[5]);
kohlerba 0:93289d2d6bce 577 // Serial.println(factoryTrim[0]); Serial.println(factoryTrim[1]); Serial.println(factoryTrim[2]);
kohlerba 0:93289d2d6bce 578 // Serial.println(factoryTrim[3]); Serial.println(factoryTrim[4]); Serial.println(factoryTrim[5]);
kohlerba 0:93289d2d6bce 579
kohlerba 0:93289d2d6bce 580 // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response
kohlerba 0:93289d2d6bce 581 // To get to percent, must multiply by 100 and subtract result from 100
kohlerba 0:93289d2d6bce 582 for (int i = 0; i < 6; i++) {
kohlerba 0:93289d2d6bce 583 destination[i] = 100.0f + 100.0f*(selfTest[i] - factoryTrim[i])/factoryTrim[i]; // Report percent differences
kohlerba 0:93289d2d6bce 584 }
kohlerba 0:93289d2d6bce 585
kohlerba 0:93289d2d6bce 586 }
kohlerba 0:93289d2d6bce 587
kohlerba 0:93289d2d6bce 588
kohlerba 0:93289d2d6bce 589 // Implementation of Sebastian Madgwick's "...efficient orientation filter for... inertial/magnetic sensor arrays"
kohlerba 0:93289d2d6bce 590 // (see http://www.x-io.co.uk/category/open-source/ for examples and more details)
kohlerba 0:93289d2d6bce 591 // which fuses acceleration and rotation rate to produce a quaternion-based estimate of relative
kohlerba 0:93289d2d6bce 592 // device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc.
kohlerba 0:93289d2d6bce 593 // The performance of the orientation filter is at least as good as conventional Kalman-based filtering algorithms
kohlerba 0:93289d2d6bce 594 // but is much less computationally intensive---it can be performed on a 3.3 V Pro Mini operating at 8 MHz!
kohlerba 0:93289d2d6bce 595 void MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz)
kohlerba 0:93289d2d6bce 596 {
kohlerba 0:93289d2d6bce 597 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
kohlerba 0:93289d2d6bce 598 float norm; // vector norm
kohlerba 0:93289d2d6bce 599 float f1, f2, f3; // objective funcyion elements
kohlerba 0:93289d2d6bce 600 float J_11or24, J_12or23, J_13or22, J_14or21, J_32, J_33; // objective function Jacobian elements
kohlerba 0:93289d2d6bce 601 float qDot1, qDot2, qDot3, qDot4;
kohlerba 0:93289d2d6bce 602 float hatDot1, hatDot2, hatDot3, hatDot4;
kohlerba 0:93289d2d6bce 603 float gerrx, gerry, gerrz, gbiasx, gbiasy, gbiasz; // gyro bias error
kohlerba 0:93289d2d6bce 604
kohlerba 0:93289d2d6bce 605 // Auxiliary variables to avoid repeated arithmetic
kohlerba 0:93289d2d6bce 606 float _halfq1 = 0.5f * q1;
kohlerba 0:93289d2d6bce 607 float _halfq2 = 0.5f * q2;
kohlerba 0:93289d2d6bce 608 float _halfq3 = 0.5f * q3;
kohlerba 0:93289d2d6bce 609 float _halfq4 = 0.5f * q4;
kohlerba 0:93289d2d6bce 610 float _2q1 = 2.0f * q1;
kohlerba 0:93289d2d6bce 611 float _2q2 = 2.0f * q2;
kohlerba 0:93289d2d6bce 612 float _2q3 = 2.0f * q3;
kohlerba 0:93289d2d6bce 613 float _2q4 = 2.0f * q4;
kohlerba 0:93289d2d6bce 614 // float _2q1q3 = 2.0f * q1 * q3;
kohlerba 0:93289d2d6bce 615 // float _2q3q4 = 2.0f * q3 * q4;
kohlerba 0:93289d2d6bce 616
kohlerba 0:93289d2d6bce 617 // Normalise accelerometer measurement
kohlerba 0:93289d2d6bce 618 norm = sqrt(ax * ax + ay * ay + az * az);
kohlerba 0:93289d2d6bce 619 if (norm == 0.0f) return; // handle NaN
kohlerba 0:93289d2d6bce 620 norm = 1.0f/norm;
kohlerba 0:93289d2d6bce 621 ax *= norm;
kohlerba 0:93289d2d6bce 622 ay *= norm;
kohlerba 0:93289d2d6bce 623 az *= norm;
kohlerba 0:93289d2d6bce 624
kohlerba 0:93289d2d6bce 625 // Compute the objective function and Jacobian
kohlerba 0:93289d2d6bce 626 f1 = _2q2 * q4 - _2q1 * q3 - ax;
kohlerba 0:93289d2d6bce 627 f2 = _2q1 * q2 + _2q3 * q4 - ay;
kohlerba 0:93289d2d6bce 628 f3 = 1.0f - _2q2 * q2 - _2q3 * q3 - az;
kohlerba 0:93289d2d6bce 629 J_11or24 = _2q3;
kohlerba 0:93289d2d6bce 630 J_12or23 = _2q4;
kohlerba 0:93289d2d6bce 631 J_13or22 = _2q1;
kohlerba 0:93289d2d6bce 632 J_14or21 = _2q2;
kohlerba 0:93289d2d6bce 633 J_32 = 2.0f * J_14or21;
kohlerba 0:93289d2d6bce 634 J_33 = 2.0f * J_11or24;
kohlerba 0:93289d2d6bce 635
kohlerba 0:93289d2d6bce 636 // Compute the gradient (matrix multiplication)
kohlerba 0:93289d2d6bce 637 hatDot1 = J_14or21 * f2 - J_11or24 * f1;
kohlerba 0:93289d2d6bce 638 hatDot2 = J_12or23 * f1 + J_13or22 * f2 - J_32 * f3;
kohlerba 0:93289d2d6bce 639 hatDot3 = J_12or23 * f2 - J_33 *f3 - J_13or22 * f1;
kohlerba 0:93289d2d6bce 640 hatDot4 = J_14or21 * f1 + J_11or24 * f2;
kohlerba 0:93289d2d6bce 641
kohlerba 0:93289d2d6bce 642 // Normalize the gradient
kohlerba 0:93289d2d6bce 643 norm = sqrt(hatDot1 * hatDot1 + hatDot2 * hatDot2 + hatDot3 * hatDot3 + hatDot4 * hatDot4);
kohlerba 0:93289d2d6bce 644 hatDot1 /= norm;
kohlerba 0:93289d2d6bce 645 hatDot2 /= norm;
kohlerba 0:93289d2d6bce 646 hatDot3 /= norm;
kohlerba 0:93289d2d6bce 647 hatDot4 /= norm;
kohlerba 0:93289d2d6bce 648
kohlerba 0:93289d2d6bce 649 // Compute estimated gyroscope biases
kohlerba 0:93289d2d6bce 650 gerrx = _2q1 * hatDot2 - _2q2 * hatDot1 - _2q3 * hatDot4 + _2q4 * hatDot3;
kohlerba 0:93289d2d6bce 651 gerry = _2q1 * hatDot3 + _2q2 * hatDot4 - _2q3 * hatDot1 - _2q4 * hatDot2;
kohlerba 0:93289d2d6bce 652 gerrz = _2q1 * hatDot4 - _2q2 * hatDot3 + _2q3 * hatDot2 - _2q4 * hatDot1;
kohlerba 0:93289d2d6bce 653
kohlerba 0:93289d2d6bce 654 // Compute and remove gyroscope biases
kohlerba 0:93289d2d6bce 655 gbiasx += gerrx * deltat * zeta;
kohlerba 0:93289d2d6bce 656 gbiasy += gerry * deltat * zeta;
kohlerba 0:93289d2d6bce 657 gbiasz += gerrz * deltat * zeta;
kohlerba 0:93289d2d6bce 658 // gx -= gbiasx;
kohlerba 0:93289d2d6bce 659 // gy -= gbiasy;
kohlerba 0:93289d2d6bce 660 // gz -= gbiasz;
kohlerba 0:93289d2d6bce 661
kohlerba 0:93289d2d6bce 662 // Compute the quaternion derivative
kohlerba 0:93289d2d6bce 663 qDot1 = -_halfq2 * gx - _halfq3 * gy - _halfq4 * gz;
kohlerba 0:93289d2d6bce 664 qDot2 = _halfq1 * gx + _halfq3 * gz - _halfq4 * gy;
kohlerba 0:93289d2d6bce 665 qDot3 = _halfq1 * gy - _halfq2 * gz + _halfq4 * gx;
kohlerba 0:93289d2d6bce 666 qDot4 = _halfq1 * gz + _halfq2 * gy - _halfq3 * gx;
kohlerba 0:93289d2d6bce 667
kohlerba 0:93289d2d6bce 668 // Compute then integrate estimated quaternion derivative
kohlerba 0:93289d2d6bce 669 q1 += (qDot1 -(beta * hatDot1)) * deltat;
kohlerba 0:93289d2d6bce 670 q2 += (qDot2 -(beta * hatDot2)) * deltat;
kohlerba 0:93289d2d6bce 671 q3 += (qDot3 -(beta * hatDot3)) * deltat;
kohlerba 0:93289d2d6bce 672 q4 += (qDot4 -(beta * hatDot4)) * deltat;
kohlerba 0:93289d2d6bce 673
kohlerba 0:93289d2d6bce 674 // Normalize the quaternion
kohlerba 0:93289d2d6bce 675 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion
kohlerba 0:93289d2d6bce 676 norm = 1.0f/norm;
kohlerba 0:93289d2d6bce 677 q[0] = q1 * norm;
kohlerba 0:93289d2d6bce 678 q[1] = q2 * norm;
kohlerba 0:93289d2d6bce 679 q[2] = q3 * norm;
kohlerba 0:93289d2d6bce 680 q[3] = q4 * norm;
kohlerba 0:93289d2d6bce 681
kohlerba 0:93289d2d6bce 682 }
kohlerba 0:93289d2d6bce 683
kohlerba 0:93289d2d6bce 684
kohlerba 0:93289d2d6bce 685 };
kohlerba 0:93289d2d6bce 686 #endif