Kamil Foryszewski / MPU6050

MPU6050 library using i2c interface on LPC1768 - Complementary filter is added. Now program can calculate pitch and roll angles.

Fork of MPU6050 by Baser Kandehir

MPU6050.cpp@7:e4e02c9c1381, 2016-11-03 (annotated)

Committer:
kfforex
Date:
Thu Nov 03 17:14:54 2016 +0000
Revision:
7:e4e02c9c1381
Parent:
6:5b90f2b5e6d9 
before publishing

Who changed what in which revision?

UserRevisionLine numberNew contents of line
BaserK 4:20f1f660e5c3 1 /* MPU6050 Library
BaserK 4:20f1f660e5c3 2 *
BaserK 4:20f1f660e5c3 3 * @author: Baser Kandehir
BaserK 2:3e0dfce73a58 4 * @date: July 16, 2015
BaserK 3:a173ad187e67 5 * @license: MIT license
BaserK 0:954f15bd95f1 6 */
BaserK 0:954f15bd95f1 7
BaserK 0:954f15bd95f1 8
BaserK 0:954f15bd95f1 9 #include "MPU6050.h"
BaserK 0:954f15bd95f1 10
BaserK 4:20f1f660e5c3 11 /* For NUCLEO-F411RE board */
kfforex 7:e4e02c9c1381 12 static I2C i2c(D4,D5); // setup i2c (SDA,SCL)
BaserK 0:954f15bd95f1 13
BaserK 0:954f15bd95f1 14 /* Set initial input parameters */
BaserK 0:954f15bd95f1 15
BaserK 0:954f15bd95f1 16 // Acc Full Scale Range +-2G 4G 8G 16G
BaserK 0:954f15bd95f1 17 enum Ascale
BaserK 0:954f15bd95f1 18 {
BaserK 0:954f15bd95f1 19 AFS_2G=0,
BaserK 0:954f15bd95f1 20 AFS_4G,
BaserK 0:954f15bd95f1 21 AFS_8G,
BaserK 0:954f15bd95f1 22 AFS_16G
BaserK 0:954f15bd95f1 23 };
BaserK 0:954f15bd95f1 24
BaserK 0:954f15bd95f1 25 // Gyro Full Scale Range +-250 500 1000 2000 Degrees per second
BaserK 0:954f15bd95f1 26 enum Gscale
BaserK 0:954f15bd95f1 27 {
BaserK 0:954f15bd95f1 28 GFS_250DPS=0,
BaserK 0:954f15bd95f1 29 GFS_500DPS,
BaserK 0:954f15bd95f1 30 GFS_1000DPS,
BaserK 0:954f15bd95f1 31 GFS_2000DPS
BaserK 0:954f15bd95f1 32 };
BaserK 0:954f15bd95f1 33
BaserK 0:954f15bd95f1 34 // Sensor datas
BaserK 0:954f15bd95f1 35 float ax,ay,az;
BaserK 0:954f15bd95f1 36 float gx,gy,gz;
BaserK 0:954f15bd95f1 37 int16_t accelData[3],gyroData[3],tempData;
BaserK 0:954f15bd95f1 38 float accelBias[3] = {0, 0, 0}; // Bias corrections for acc
BaserK 0:954f15bd95f1 39 float gyroBias[3] = {0, 0, 0}; // Bias corrections for gyro
BaserK 0:954f15bd95f1 40
BaserK 0:954f15bd95f1 41 // Specify sensor full scale range
BaserK 0:954f15bd95f1 42 int Ascale = AFS_2G;
BaserK 0:954f15bd95f1 43 int Gscale = GFS_250DPS;
BaserK 0:954f15bd95f1 44
BaserK 0:954f15bd95f1 45 // Scale resolutions per LSB for the sensors
BaserK 0:954f15bd95f1 46 float aRes, gRes;
BaserK 0:954f15bd95f1 47
BaserK 0:954f15bd95f1 48 // Calculates Acc resolution
BaserK 0:954f15bd95f1 49 void MPU6050::getAres()
BaserK 0:954f15bd95f1 50 {
BaserK 0:954f15bd95f1 51 switch(Ascale)
BaserK 0:954f15bd95f1 52 {
BaserK 0:954f15bd95f1 53 case AFS_2G:
BaserK 0:954f15bd95f1 54 aRes = 2.0/32768.0;
BaserK 0:954f15bd95f1 55 break;
BaserK 0:954f15bd95f1 56 case AFS_4G:
BaserK 0:954f15bd95f1 57 aRes = 4.0/32768.0;
BaserK 0:954f15bd95f1 58 break;
BaserK 0:954f15bd95f1 59 case AFS_8G:
BaserK 0:954f15bd95f1 60 aRes = 8.0/32768.0;
BaserK 0:954f15bd95f1 61 break;
BaserK 0:954f15bd95f1 62 case AFS_16G:
BaserK 0:954f15bd95f1 63 aRes = 16.0/32768.0;
BaserK 0:954f15bd95f1 64 break;
BaserK 0:954f15bd95f1 65 }
BaserK 0:954f15bd95f1 66 }
BaserK 0:954f15bd95f1 67
BaserK 0:954f15bd95f1 68 // Calculates Gyro resolution
BaserK 0:954f15bd95f1 69 void MPU6050::getGres()
BaserK 0:954f15bd95f1 70 {
BaserK 0:954f15bd95f1 71 switch(Gscale)
BaserK 0:954f15bd95f1 72 {
BaserK 0:954f15bd95f1 73 case GFS_250DPS:
BaserK 0:954f15bd95f1 74 gRes = 250.0/32768.0;
BaserK 0:954f15bd95f1 75 break;
BaserK 0:954f15bd95f1 76 case GFS_500DPS:
BaserK 0:954f15bd95f1 77 gRes = 500.0/32768.0;
BaserK 0:954f15bd95f1 78 break;
BaserK 0:954f15bd95f1 79 case GFS_1000DPS:
BaserK 0:954f15bd95f1 80 gRes = 1000.0/32768.0;
BaserK 0:954f15bd95f1 81 break;
BaserK 0:954f15bd95f1 82 case GFS_2000DPS:
BaserK 0:954f15bd95f1 83 gRes = 2000.0/32768.0;
BaserK 0:954f15bd95f1 84 break;
BaserK 0:954f15bd95f1 85 }
BaserK 0:954f15bd95f1 86 }
BaserK 0:954f15bd95f1 87
BaserK 0:954f15bd95f1 88 void MPU6050::writeByte(uint8_t address, uint8_t subAddress, uint8_t data)
BaserK 0:954f15bd95f1 89 {
BaserK 0:954f15bd95f1 90 char data_write[2];
BaserK 0:954f15bd95f1 91 data_write[0]=subAddress; // I2C sends MSB first. Namely >>|subAddress|>>|data|
BaserK 0:954f15bd95f1 92 data_write[1]=data;
BaserK 0:954f15bd95f1 93 i2c.write(address,data_write,2,0); // i2c.write(int address, char* data, int length, bool repeated=false);
BaserK 0:954f15bd95f1 94 }
BaserK 0:954f15bd95f1 95
BaserK 0:954f15bd95f1 96 char MPU6050::readByte(uint8_t address, uint8_t subAddress)
BaserK 0:954f15bd95f1 97 {
BaserK 0:954f15bd95f1 98 char data_read[1]; // will store the register data
BaserK 0:954f15bd95f1 99 char data_write[1];
BaserK 0:954f15bd95f1 100 data_write[0]=subAddress;
BaserK 0:954f15bd95f1 101 i2c.write(address,data_write,1,1); // have not stopped yet
BaserK 0:954f15bd95f1 102 i2c.read(address,data_read,1,0); // read the data and stop
BaserK 0:954f15bd95f1 103 return data_read[0];
BaserK 0:954f15bd95f1 104 }
BaserK 0:954f15bd95f1 105
BaserK 0:954f15bd95f1 106 void MPU6050::readBytes(uint8_t address, uint8_t subAddress, uint8_t byteNum, uint8_t* dest)
BaserK 0:954f15bd95f1 107 {
BaserK 0:954f15bd95f1 108 char data[14],data_write[1];
BaserK 0:954f15bd95f1 109 data_write[0]=subAddress;
BaserK 0:954f15bd95f1 110 i2c.write(address,data_write,1,1);
BaserK 0:954f15bd95f1 111 i2c.read(address,data,byteNum,0);
BaserK 0:954f15bd95f1 112 for(int i=0;i<byteNum;i++) // equate the addresses
BaserK 0:954f15bd95f1 113 dest[i]=data[i];
BaserK 0:954f15bd95f1 114 }
BaserK 0:954f15bd95f1 115
BaserK 0:954f15bd95f1 116 // Communication test: WHO_AM_I register reading
BaserK 0:954f15bd95f1 117 void MPU6050::whoAmI()
BaserK 0:954f15bd95f1 118 {
BaserK 0:954f15bd95f1 119 uint8_t whoAmI = readByte(MPU6050_ADDRESS, WHO_AM_I_MPU6050); // Should return 0x68
BaserK 2:3e0dfce73a58 120 pc.printf("I AM 0x%x \r\n",whoAmI);
BaserK 0:954f15bd95f1 121
BaserK 0:954f15bd95f1 122 if(whoAmI==0x68)
BaserK 0:954f15bd95f1 123 {
BaserK 2:3e0dfce73a58 124 pc.printf("MPU6050 is online... \r\n");
BaserK 0:954f15bd95f1 125 }
BaserK 0:954f15bd95f1 126 else
BaserK 0:954f15bd95f1 127 {
BaserK 2:3e0dfce73a58 128 pc.printf("Could not connect to MPU6050 \r\nCheck the connections... \r\n");
BaserK 0:954f15bd95f1 129 }
BaserK 0:954f15bd95f1 130 }
BaserK 0:954f15bd95f1 131
BaserK 0:954f15bd95f1 132 // Initializes MPU6050 with the following config:
BaserK 0:954f15bd95f1 133 // PLL with X axis gyroscope reference
BaserK 0:954f15bd95f1 134 // Sample rate: 200Hz for gyro and acc
BaserK 0:954f15bd95f1 135 // Interrupts are disabled
BaserK 0:954f15bd95f1 136 void MPU6050::init()
BaserK 5:5bff0edcdff8 137 {
BaserK 5:5bff0edcdff8 138 i2c.frequency(400000); // fast i2c: 400 kHz
BaserK 5:5bff0edcdff8 139
BaserK 0:954f15bd95f1 140 /* Wake up the device */
BaserK 0:954f15bd95f1 141 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x00); // wake up the device by clearing the sleep bit (bit6)
BaserK 0:954f15bd95f1 142 wait_ms(100); // wait 100 ms to stabilize
BaserK 0:954f15bd95f1 143
BaserK 0:954f15bd95f1 144 /* Get stable time source */
BaserK 0:954f15bd95f1 145 // PLL with X axis gyroscope reference is used to improve stability
BaserK 0:954f15bd95f1 146 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x01);
BaserK 0:954f15bd95f1 147
BaserK 0:954f15bd95f1 148 /* Configure Gyroscope and Accelerometer */
BaserK 0:954f15bd95f1 149 // Disable FSYNC, acc bandwidth: 44 Hz, gyro bandwidth: 42 Hz
BaserK 0:954f15bd95f1 150 // Sample rates: 1kHz, maximum delay: 4.9ms (which is pretty good for a 200 Hz maximum rate)
BaserK 0:954f15bd95f1 151 writeByte(MPU6050_ADDRESS, CONFIG, 0x03);
BaserK 0:954f15bd95f1 152
BaserK 0:954f15bd95f1 153 /* Set sample rate = gyroscope output rate/(1+SMPLRT_DIV) */
BaserK 0:954f15bd95f1 154 // SMPLRT_DIV=4 and sample rate=200 Hz (compatible with config above)
BaserK 0:954f15bd95f1 155 writeByte(MPU6050_ADDRESS, SMPLRT_DIV, 0x04);
BaserK 0:954f15bd95f1 156
BaserK 0:954f15bd95f1 157 /* Accelerometer configuration */
BaserK 0:954f15bd95f1 158 uint8_t temp = readByte(MPU6050_ADDRESS, ACCEL_CONFIG);
BaserK 0:954f15bd95f1 159 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, temp & ~0xE0); // Clear self-test bits [7:5]
BaserK 0:954f15bd95f1 160 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, temp & ~0x18); // Clear AFS bits [4:3]
BaserK 0:954f15bd95f1 161 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, temp | Ascale<<3); // Set full scale range
BaserK 0:954f15bd95f1 162
BaserK 0:954f15bd95f1 163 /* Gyroscope configuration */
BaserK 0:954f15bd95f1 164 temp = readByte(MPU6050_ADDRESS, GYRO_CONFIG);
BaserK 0:954f15bd95f1 165 writeByte(MPU6050_ADDRESS, GYRO_CONFIG, temp & ~0xE0); // Clear self-test bits [7:5]
BaserK 0:954f15bd95f1 166 writeByte(MPU6050_ADDRESS, GYRO_CONFIG, temp & ~0x18); // Clear FS bits [4:3]
BaserK 0:954f15bd95f1 167 writeByte(MPU6050_ADDRESS, GYRO_CONFIG, temp | Gscale<<3); // Set full scale range
BaserK 0:954f15bd95f1 168 }
BaserK 0:954f15bd95f1 169
BaserK 0:954f15bd95f1 170 // Resets the device
BaserK 0:954f15bd95f1 171 void MPU6050::reset()
BaserK 0:954f15bd95f1 172 {
BaserK 0:954f15bd95f1 173 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x80); // set bit7 to reset the device
BaserK 0:954f15bd95f1 174 wait_ms(100); // wait 100 ms to stabilize
BaserK 0:954f15bd95f1 175 }
BaserK 0:954f15bd95f1 176
BaserK 0:954f15bd95f1 177 void MPU6050::readAccelData(int16_t* dest)
BaserK 0:954f15bd95f1 178 {
BaserK 0:954f15bd95f1 179 uint8_t rawData[6]; // x,y,z acc data
BaserK 0:954f15bd95f1 180 readBytes(MPU6050_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // read six raw data registers sequentially and write them into data array
BaserK 0:954f15bd95f1 181
BaserK 0:954f15bd95f1 182 /* Turn the MSB LSB into signed 16-bit value */
BaserK 0:954f15bd95f1 183 dest[0] = (int16_t)(((int16_t)rawData[0]<<8) | rawData[1]); // ACCEL_XOUT
BaserK 0:954f15bd95f1 184 dest[1] = (int16_t)(((int16_t)rawData[2]<<8) | rawData[3]); // ACCEL_YOUT
BaserK 0:954f15bd95f1 185 dest[2] = (int16_t)(((int16_t)rawData[4]<<8) | rawData[5]); // ACCEL_ZOUT
BaserK 0:954f15bd95f1 186 }
BaserK 0:954f15bd95f1 187
BaserK 0:954f15bd95f1 188 void MPU6050::readGyroData(int16_t* dest)
BaserK 0:954f15bd95f1 189 {
BaserK 0:954f15bd95f1 190 uint8_t rawData[6]; // x,y,z gyro data
BaserK 0:954f15bd95f1 191 readBytes(MPU6050_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // read the six raw data registers sequentially and write them into data array
BaserK 0:954f15bd95f1 192
BaserK 0:954f15bd95f1 193 /* Turn the MSB LSB into signed 16-bit value */
BaserK 0:954f15bd95f1 194 dest[0] = (int16_t)(((int16_t)rawData[0]<<8) | rawData[1]); // GYRO_XOUT
BaserK 0:954f15bd95f1 195 dest[1] = (int16_t)(((int16_t)rawData[2]<<8) | rawData[3]); // GYRO_YOUT
BaserK 0:954f15bd95f1 196 dest[2] = (int16_t)(((int16_t)rawData[4]<<8) | rawData[5]); // GYRO_ZOUT
BaserK 0:954f15bd95f1 197 }
BaserK 0:954f15bd95f1 198
BaserK 0:954f15bd95f1 199 int16_t MPU6050::readTempData()
BaserK 0:954f15bd95f1 200 {
BaserK 0:954f15bd95f1 201 uint8_t rawData[2]; // temperature data
BaserK 0:954f15bd95f1 202 readBytes(MPU6050_ADDRESS, TEMP_OUT_H, 2, &rawData[0]); // read the two raw data registers sequentially and write them into data array
BaserK 0:954f15bd95f1 203 return (int16_t)(((int16_t)rawData[0]<<8) | rawData[1]); // turn the MSB LSB into signed 16-bit value
BaserK 0:954f15bd95f1 204 }
BaserK 0:954f15bd95f1 205
BaserK 0:954f15bd95f1 206 /* Function which accumulates gyro and accelerometer data after device initialization.
BaserK 0:954f15bd95f1 207 It calculates the average of the at-rest readings and
BaserK 0:954f15bd95f1 208 then loads the resulting offsets into accelerometer and gyro bias registers. */
BaserK 0:954f15bd95f1 209 /*
BaserK 0:954f15bd95f1 210 IMPORTANT NOTE: In this function;
BaserK 0:954f15bd95f1 211 Resulting accel offsets are NOT pushed to the accel bias registers. accelBias[i] offsets are used in the main program.
BaserK 0:954f15bd95f1 212 Resulting gyro offsets are pushed to the gyro bias registers. gyroBias[i] offsets are NOT used in the main program.
BaserK 0:954f15bd95f1 213 Resulting data seems satisfactory.
BaserK 0:954f15bd95f1 214 */
BaserK 0:954f15bd95f1 215 // dest1: accelBias dest2: gyroBias
BaserK 0:954f15bd95f1 216 void MPU6050::calibrate(float* dest1, float* dest2)
BaserK 0:954f15bd95f1 217 {
BaserK 0:954f15bd95f1 218 uint8_t data[12]; // data array to hold acc and gyro x,y,z data
BaserK 0:954f15bd95f1 219 uint16_t fifo_count, packet_count, count;
BaserK 0:954f15bd95f1 220 int32_t accel_bias[3] = {0,0,0};
BaserK 0:954f15bd95f1 221 int32_t gyro_bias[3] = {0,0,0};
BaserK 0:954f15bd95f1 222 float aRes = 2.0/32768.0;
BaserK 0:954f15bd95f1 223 float gRes = 250.0/32768.0;
BaserK 0:954f15bd95f1 224 uint16_t accelsensitivity = 16384; // = 1/aRes = 16384 LSB/g
BaserK 0:954f15bd95f1 225 //uint16_t gyrosensitivity = 131; // = 1/gRes = 131 LSB/dps
BaserK 0:954f15bd95f1 226
BaserK 0:954f15bd95f1 227 reset(); // Reset device
BaserK 0:954f15bd95f1 228
BaserK 0:954f15bd95f1 229 /* Get stable time source */
BaserK 0:954f15bd95f1 230 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x01); // PLL with X axis gyroscope reference is used to improve stability
BaserK 0:954f15bd95f1 231 writeByte(MPU6050_ADDRESS, PWR_MGMT_2, 0x00); // Disable accel only low power mode
BaserK 0:954f15bd95f1 232 wait(0.2);
BaserK 0:954f15bd95f1 233
BaserK 0:954f15bd95f1 234 /* Configure device for bias calculation */
BaserK 0:954f15bd95f1 235 writeByte(MPU6050_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts
BaserK 0:954f15bd95f1 236 writeByte(MPU6050_ADDRESS, FIFO_EN, 0x00); // Disable FIFO
BaserK 0:954f15bd95f1 237 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source
BaserK 0:954f15bd95f1 238 writeByte(MPU6050_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master
BaserK 0:954f15bd95f1 239 writeByte(MPU6050_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes
BaserK 0:954f15bd95f1 240 writeByte(MPU6050_ADDRESS, USER_CTRL, 0x04); // Reset FIFO
BaserK 0:954f15bd95f1 241 wait(0.015);
BaserK 0:954f15bd95f1 242
BaserK 0:954f15bd95f1 243 /* Configure accel and gyro for bias calculation */
BaserK 0:954f15bd95f1 244 writeByte(MPU6050_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz
BaserK 0:954f15bd95f1 245 writeByte(MPU6050_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz
BaserK 0:954f15bd95f1 246 writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity
BaserK 0:954f15bd95f1 247 writeByte(MPU6050_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity
BaserK 0:954f15bd95f1 248
BaserK 0:954f15bd95f1 249 /* Configure FIFO to capture accelerometer and gyro data for bias calculation */
BaserK 0:954f15bd95f1 250 writeByte(MPU6050_ADDRESS, USER_CTRL, 0x40); // Enable FIFO
BaserK 0:954f15bd95f1 251 writeByte(MPU6050_ADDRESS, FIFO_EN, 0x78); // Enable accelerometer and gyro for FIFO (max size 1024 bytes in MPU-6050)
BaserK 0:954f15bd95f1 252 wait(0.08); // Sample rate is 1 kHz, accumulates 80 samples in 80 milliseconds.
BaserK 0:954f15bd95f1 253 // accX: 2 byte, accY: 2 byte, accZ: 2 byte. gyroX: 2 byte, gyroY: 2 byte, gyroZ: 2 byte. 12*80=960 byte < 1024 byte
BaserK 0:954f15bd95f1 254
BaserK 0:954f15bd95f1 255 /* At end of sample accumulation, turn off FIFO sensor read */
BaserK 0:954f15bd95f1 256 writeByte(MPU6050_ADDRESS, FIFO_EN, 0x00); // Disable FIFO
BaserK 0:954f15bd95f1 257 readBytes(MPU6050_ADDRESS, FIFO_COUNTH, 2, &data[0]); // Read FIFO sample count
BaserK 0:954f15bd95f1 258 fifo_count = ((uint16_t)data[0] << 8) | data[1];
BaserK 0:954f15bd95f1 259 packet_count = fifo_count/12; // The number of sets of full acc and gyro data for averaging. packet_count = 80 in this case
BaserK 0:954f15bd95f1 260
BaserK 0:954f15bd95f1 261 for(count=0; count<packet_count; count++)
BaserK 0:954f15bd95f1 262 {
BaserK 0:954f15bd95f1 263 int16_t accel_temp[3]={0,0,0};
BaserK 0:954f15bd95f1 264 int16_t gyro_temp[3]={0,0,0};
BaserK 0:954f15bd95f1 265 readBytes(MPU6050_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging
BaserK 0:954f15bd95f1 266
BaserK 0:954f15bd95f1 267 /* Form signed 16-bit integer for each sample in FIFO */
BaserK 0:954f15bd95f1 268 accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ;
BaserK 0:954f15bd95f1 269 accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ;
BaserK 0:954f15bd95f1 270 accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ;
BaserK 0:954f15bd95f1 271 gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ;
BaserK 0:954f15bd95f1 272 gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ;
BaserK 0:954f15bd95f1 273 gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ;
BaserK 0:954f15bd95f1 274
BaserK 0:954f15bd95f1 275 /* Sum individual signed 16-bit biases to get accumulated signed 32-bit biases */
BaserK 0:954f15bd95f1 276 accel_bias[0] += (int32_t) accel_temp[0];
BaserK 0:954f15bd95f1 277 accel_bias[1] += (int32_t) accel_temp[1];
BaserK 0:954f15bd95f1 278 accel_bias[2] += (int32_t) accel_temp[2];
BaserK 0:954f15bd95f1 279 gyro_bias[0] += (int32_t) gyro_temp[0];
BaserK 0:954f15bd95f1 280 gyro_bias[1] += (int32_t) gyro_temp[1];
BaserK 0:954f15bd95f1 281 gyro_bias[2] += (int32_t) gyro_temp[2];
BaserK 0:954f15bd95f1 282 }
BaserK 0:954f15bd95f1 283
BaserK 0:954f15bd95f1 284 /* Normalize sums to get average count biases */
BaserK 0:954f15bd95f1 285 accel_bias[0] /= (int32_t) packet_count;
BaserK 0:954f15bd95f1 286 accel_bias[1] /= (int32_t) packet_count;
BaserK 0:954f15bd95f1 287 accel_bias[2] /= (int32_t) packet_count;
BaserK 0:954f15bd95f1 288 gyro_bias[0] /= (int32_t) packet_count;
BaserK 0:954f15bd95f1 289 gyro_bias[1] /= (int32_t) packet_count;
BaserK 0:954f15bd95f1 290 gyro_bias[2] /= (int32_t) packet_count;
BaserK 0:954f15bd95f1 291
BaserK 0:954f15bd95f1 292 /* Remove gravity from the z-axis accelerometer bias calculation */
BaserK 0:954f15bd95f1 293 if(accel_bias[2] > 0) {accel_bias[2] -= (int32_t) accelsensitivity;}
BaserK 0:954f15bd95f1 294 else {accel_bias[2] += (int32_t) accelsensitivity;}
BaserK 0:954f15bd95f1 295
BaserK 0:954f15bd95f1 296 /* Output scaled accelerometer biases for manual subtraction in the main program */
BaserK 0:954f15bd95f1 297 dest1[0] = accel_bias[0]*aRes;
BaserK 0:954f15bd95f1 298 dest1[1] = accel_bias[1]*aRes;
BaserK 0:954f15bd95f1 299 dest1[2] = accel_bias[2]*aRes;
BaserK 0:954f15bd95f1 300
BaserK 0:954f15bd95f1 301 /* Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup */
BaserK 0:954f15bd95f1 302 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
BaserK 0:954f15bd95f1 303 data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
BaserK 0:954f15bd95f1 304 data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF;
BaserK 0:954f15bd95f1 305 data[3] = (-gyro_bias[1]/4) & 0xFF;
BaserK 0:954f15bd95f1 306 data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF;
BaserK 0:954f15bd95f1 307 data[5] = (-gyro_bias[2]/4) & 0xFF;
BaserK 0:954f15bd95f1 308
BaserK 0:954f15bd95f1 309 /* Push gyro biases to hardware registers */
BaserK 0:954f15bd95f1 310 writeByte(MPU6050_ADDRESS, XG_OFFS_USRH, data[0]);
BaserK 0:954f15bd95f1 311 writeByte(MPU6050_ADDRESS, XG_OFFS_USRL, data[1]);
BaserK 0:954f15bd95f1 312 writeByte(MPU6050_ADDRESS, YG_OFFS_USRH, data[2]);
BaserK 0:954f15bd95f1 313 writeByte(MPU6050_ADDRESS, YG_OFFS_USRL, data[3]);
BaserK 0:954f15bd95f1 314 writeByte(MPU6050_ADDRESS, ZG_OFFS_USRH, data[4]);
BaserK 0:954f15bd95f1 315 writeByte(MPU6050_ADDRESS, ZG_OFFS_USRL, data[5]);
BaserK 0:954f15bd95f1 316
BaserK 0:954f15bd95f1 317 /* Construct gyro bias in deg/s for later manual subtraction */
BaserK 0:954f15bd95f1 318 dest2[0] = gyro_bias[0]*gRes;
BaserK 0:954f15bd95f1 319 dest2[1] = gyro_bias[1]*gRes;
BaserK 0:954f15bd95f1 320 dest2[2] = gyro_bias[2]*gRes;
BaserK 0:954f15bd95f1 321 }
BaserK 2:3e0dfce73a58 322
BaserK 2:3e0dfce73a58 323 void MPU6050::complementaryFilter(float* pitch, float* roll)
BaserK 2:3e0dfce73a58 324 {
BaserK 2:3e0dfce73a58 325 /* Get actual acc value */
BaserK 2:3e0dfce73a58 326 readAccelData(accelData);
BaserK 2:3e0dfce73a58 327 getAres();
BaserK 2:3e0dfce73a58 328 ax = accelData[0]*aRes - accelBias[0];
BaserK 2:3e0dfce73a58 329 ay = accelData[1]*aRes - accelBias[1];
BaserK 2:3e0dfce73a58 330 az = accelData[2]*aRes - accelBias[2];
BaserK 2:3e0dfce73a58 331
BaserK 2:3e0dfce73a58 332 /* Get actual gyro value */
BaserK 2:3e0dfce73a58 333 readGyroData(gyroData);
BaserK 2:3e0dfce73a58 334 getGres();
kfforex 7:e4e02c9c1381 335 gx = gyroData[0]*gRes; // Results are better without extracting gyroBias[i]
kfforex 7:e4e02c9c1381 336 gy = gyroData[1]*gRes;
kfforex 7:e4e02c9c1381 337 gz = gyroData[2]*gRes;
BaserK 2:3e0dfce73a58 338
BaserK 2:3e0dfce73a58 339 float pitchAcc, rollAcc;
BaserK 2:3e0dfce73a58 340
BaserK 2:3e0dfce73a58 341 /* Integrate the gyro data(deg/s) over time to get angle */
BaserK 2:3e0dfce73a58 342 *pitch += gx * dt; // Angle around the X-axis
BaserK 2:3e0dfce73a58 343 *roll -= gy * dt; // Angle around the Y-axis
BaserK 2:3e0dfce73a58 344
BaserK 2:3e0dfce73a58 345 /* Turning around the X-axis results in a vector on the Y-axis
BaserK 2:3e0dfce73a58 346 whereas turning around the Y-axis results in a vector on the X-axis. */
BaserK 2:3e0dfce73a58 347 pitchAcc = atan2f(accelData[1], accelData[2])*180/PI;
BaserK 2:3e0dfce73a58 348 rollAcc = atan2f(accelData[0], accelData[2])*180/PI;
BaserK 2:3e0dfce73a58 349
BaserK 2:3e0dfce73a58 350 /* Apply Complementary Filter */
BaserK 2:3e0dfce73a58 351 *pitch = *pitch * 0.98 + pitchAcc * 0.02;
BaserK 2:3e0dfce73a58 352 *roll = *roll * 0.98 + rollAcc * 0.02;
BaserK 2:3e0dfce73a58 353 }