Alan Huchin Herrera
Quadrirotor
Dependencies: CommonTypes ESC Matrix PID Servo kalman mbed-rtos mbed
Fork of
Nucleo_MPU_9250
by 
Alan Huchin Herrera
Embed:
(wiki syntax)
Show/hide line numbers
MPU9250.cpp
00001 #include "MPU9250.h" 00002 00003 // Set initial input parameters 00004 enum Ascale { 00005 AFS_2G = 0, 00006 AFS_4G, 00007 AFS_8G, 00008 AFS_16G 00009 }; 00010 00011 enum Gscale { 00012 GFS_250DPS = 0, 00013 GFS_500DPS, 00014 GFS_1000DPS, 00015 GFS_2000DPS 00016 }; 00017 00018 enum Mscale { 00019 MFS_14BITS = 0, // 0.6 mG per LSB 00020 MFS_16BITS // 0.15 mG per LSB 00021 }; 00022 00023 float ax,ay,az; 00024 float gx,gy,gz; 00025 float mx,my,mz; 00026 int16_t accelData[3],gyroData[3],tempData; 00027 float accelBias[3] = {0, 0, 0}; // Bias corrections for acc 00028 float gyroBias[3] = {0, 0, 0}; 00029 extern float magCalibration[3]= {0, 0, 0}; 00030 extern float magbias[3]= {0, 0, 0}, magScale[3] = {0, 0, 0}; 00031 float SelfTest[6]; 00032 00033 int delt_t = 0; // used to control display output rate 00034 int count = 0; // used to control display output rate 00035 00036 // parameters for 6 DoF sensor fusion calculations 00037 float PI = 3.14159265358979323846f; 00038 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 00039 float beta = sqrt(3.0f / 4.0f) * GyroMeasError; // compute beta 00040 float GyroMeasDrift = PI * (1.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s) 00041 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 00042 #define Kp 0.98 // these are the free parameters in the Mahony filter and fusion scheme, Kp for proportional feedback, Ki for integral 00043 #define Ki 0.0000001f 00044 00045 float pitch, yaw, roll; 00046 float deltat = 0.0f; // integration interval for both filter schemes 00047 int lastUpdate = 0, firstUpdate = 0, Now = 0; // used to calculate integration interval // used to calculate integration interval 00048 float q[4] = {1.0f, 0.0f, 0.0f, 0.0f}; // vector to hold quaternion 00049 float eInt[3] = {0.0f, 0.0f, 0.0f}; 00050 00051 uint8_t Ascale = AFS_16G; // AFS_2G, AFS_4G, AFS_8G, AFS_16G 00052 uint8_t Gscale = GFS_2000DPS; // GFS_250DPS, GFS_500DPS, GFS_1000DPS, GFS_2000DPS 00053 uint8_t Mscale = MFS_16BITS; // MFS_14BITS or MFS_16BITS, 14-bit or 16-bit magnetometer resolution 00054 uint8_t Mmode = 0x06; // Either 8 Hz 0x02) or 100 Hz (0x06) magnetometer data ODR 00055 float aRes, gRes, mRes; 00056 00057 MPU9250::MPU9250(PinName sda, PinName scl) : i2c(sda, scl) { 00058 //this->setSleepMode(false); 00059 i2c.frequency(400000); 00060 //Initializations: 00061 currentGyroRange = 0; 00062 currentAcceleroRange=0; 00063 } 00064 00065 //-------------------------------------------------- 00066 //--------------------CONFIG------------------------ 00067 //-------------------------------------------------- 00068 00069 void MPU9250::getAres() 00070 { 00071 switch(Ascale) 00072 { 00073 case AFS_2G: 00074 aRes = 2.0/32768.0; 00075 break; 00076 case AFS_4G: 00077 aRes = 4.0/32768.0; 00078 break; 00079 case AFS_8G: 00080 aRes = 8.0/32768.0; 00081 break; 00082 case AFS_16G: 00083 aRes = 16.0/32768.0; 00084 break; 00085 } 00086 } 00087 00088 void MPU9250::getGres() 00089 { 00090 switch(Gscale) 00091 { 00092 case GFS_250DPS: 00093 gRes = 250.0/32768.0; 00094 break; 00095 case GFS_500DPS: 00096 gRes = 500.0/32768.0; 00097 break; 00098 case GFS_1000DPS: 00099 gRes = 1000.0/32768.0; 00100 break; 00101 case GFS_2000DPS: 00102 gRes = 2000.0/32768.0; 00103 break; 00104 } 00105 } 00106 00107 void MPU9250::getMres() { 00108 switch (Mscale) 00109 { 00110 // Possible magnetometer scales (and their register bit settings) are: 00111 // 14 bit resolution (0) and 16 bit resolution (1) 00112 case MFS_14BITS: 00113 mRes = 10.0*4219.0/8190.0; // Proper scale to return milliGauss 00114 break; 00115 case MFS_16BITS: 00116 mRes = 10.0*4219.0/32760.0; // Proper scale to return milliGauss 00117 break; 00118 } 00119 } 00120 //-------------------------------------------------- 00121 //-------------------General------------------------ 00122 //-------------------------------------------------- 00123 00124 void MPU9250::writeByte(uint8_t address, uint8_t subAddress, uint8_t data) 00125 { 00126 char data_write[2]; 00127 data_write[0] = subAddress; 00128 data_write[1] = data; 00129 i2c.write(address, data_write, 2, 0); 00130 } 00131 00132 char MPU9250::readByte(uint8_t address, uint8_t subAddress) 00133 { 00134 char data[1]; // `data` will store the register data 00135 char data_write[1]; 00136 data_write[0] = subAddress; 00137 i2c.write(address, data_write, 1, 1); // no stop 00138 i2c.read(address, data, 1, 0); 00139 return data[0]; 00140 } 00141 00142 void MPU9250::readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest) 00143 { 00144 char data[14]; 00145 char data_write[1]; 00146 data_write[0] = subAddress; 00147 i2c.write(address, data_write, 1, 1); // no stop 00148 i2c.read(address, data, count, 0); 00149 for(int ii = 0; ii < count; ii++) { 00150 dest[ii] = data[ii]; 00151 } 00152 } 00153 00154 00155 void MPU9250::readAccelData(int16_t * destination) 00156 { 00157 uint8_t rawData[6]; // x/y/z accel register data stored here 00158 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array 00159 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value 00160 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; 00161 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 00162 } 00163 00164 void MPU9250::readGyroData(int16_t * destination) 00165 { 00166 uint8_t rawData[6]; // x/y/z gyro register data stored here 00167 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array 00168 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value 00169 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; 00170 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 00171 } 00172 00173 void MPU9250::readMagData(int16_t * destination) 00174 { 00175 uint8_t rawData[7]; // x/y/z gyro register data, ST2 register stored here, must read ST2 at end of data acquisition 00176 if(readByte(AK8963_ADDRESS, AK8963_ST1) & 0x01) { // wait for magnetometer data ready bit to be set 00177 readBytes(AK8963_ADDRESS, AK8963_XOUT_L, 7, &rawData[0]); // Read the six raw data and ST2 registers sequentially into data array 00178 uint8_t c = rawData[6]; // End data read by reading ST2 register 00179 if(!(c & 0x08)) { // Check if magnetic sensor overflow set, if not then report data 00180 destination[0] = (int16_t)(((int16_t)rawData[1] << 8) | rawData[0]); // Turn the MSB and LSB into a signed 16-bit value 00181 destination[1] = (int16_t)(((int16_t)rawData[3] << 8) | rawData[2]) ; // Data stored as little Endian 00182 destination[2] = (int16_t)(((int16_t)rawData[5] << 8) | rawData[4]) ; 00183 } 00184 } 00185 } 00186 00187 int16_t MPU9250::readTempData() 00188 { 00189 uint8_t rawData[2]; // x/y/z gyro register data stored here 00190 readBytes(MPU9250_ADDRESS, TEMP_OUT_H, 2, &rawData[0]); // Read the two raw data registers sequentially into data array 00191 return (int16_t)(((int16_t)rawData[0]) << 8 | rawData[1]) ; // Turn the MSB and LSB into a 16-bit value 00192 } 00193 00194 void MPU9250::resetMPU9250() { 00195 // reset device 00196 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device 00197 wait(0.1); 00198 } 00199 00200 void MPU9250::initAK8963(float * destination) 00201 { 00202 // First extract the factory calibration for each magnetometer axis 00203 uint8_t rawData[3]; // x/y/z gyro calibration data stored here 00204 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer 00205 wait(0.01); 00206 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x0F); // Enter Fuse ROM access mode 00207 wait(0.01); 00208 readBytes(AK8963_ADDRESS, AK8963_ASAX, 3, &rawData[0]); // Read the x-, y-, and z-axis calibration values 00209 destination[0] = (float)(rawData[0] - 128)/256.0f + 1.0f; // Return x-axis sensitivity adjustment values, etc. 00210 destination[1] = (float)(rawData[1] - 128)/256.0f + 1.0f; 00211 destination[2] = (float)(rawData[2] - 128)/256.0f + 1.0f; 00212 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer 00213 wait(0.01); 00214 // Configure the magnetometer for continuous read and highest resolution 00215 // set Mscale bit 4 to 1 (0) to enable 16 (14) bit resolution in CNTL register, 00216 // and enable continuous mode data acquisition Mmode (bits [3:0]), 0010 for 8 Hz and 0110 for 100 Hz sample rates 00217 writeByte(AK8963_ADDRESS, AK8963_CNTL, Mscale << 4 | Mmode); // Set magnetometer data resolution and sample ODR 00218 wait(0.01); 00219 } 00220 00221 void MPU9250::initMPU9250() 00222 { 00223 // Initialize MPU9250 device 00224 // wake up device 00225 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors 00226 wait(0.1); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt 00227 00228 // get stable time source 00229 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01); // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001 00230 00231 // Configure Gyro and Accelerometer 00232 // Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively; 00233 // DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both 00234 // Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate 00235 writeByte(MPU9250_ADDRESS, CONFIG, 0x03); 00236 00237 // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV) 00238 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x04); // Use a 200 Hz rate; the same rate set in CONFIG above 00239 00240 // Set gyroscope full scale range 00241 // Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3 00242 uint8_t c = readByte(MPU9250_ADDRESS, GYRO_CONFIG); // get current GYRO_CONFIG register value 00243 // c = c & ~0xE0; // Clear self-test bits [7:5] 00244 c = c & ~0x02; // Clear Fchoice bits [1:0] 00245 c = c & ~0x18; // Clear AFS bits [4:3] 00246 c = c | Gscale << 3; // Set full scale range for the gyro 00247 // c =| 0x00; // Set Fchoice for the gyro to 11 by writing its inverse to bits 1:0 of GYRO_CONFIG 00248 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c ); // Write new GYRO_CONFIG value to register 00249 00250 // Set accelerometer full-scale range configuration 00251 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG); // get current ACCEL_CONFIG register value 00252 // c = c & ~0xE0; // Clear self-test bits [7:5] 00253 c = c & ~0x18; // Clear AFS bits [4:3] 00254 c = c | Ascale << 3; // Set full scale range for the accelerometer 00255 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c); // Write new ACCEL_CONFIG register value 00256 00257 // Set accelerometer sample rate configuration 00258 // It is possible to get a 4 kHz sample rate from the accelerometer by choosing 1 for 00259 // accel_fchoice_b bit [3]; in this case the bandwidth is 1.13 kHz 00260 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG2); // get current ACCEL_CONFIG2 register value 00261 c = c & ~0x0F; // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0]) 00262 c = c | 0x03; // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz 00263 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c); // Write new ACCEL_CONFIG2 register value 00264 00265 // The accelerometer, gyro, and thermometer are set to 1 kHz sample rates, 00266 // but all these rates are further reduced by a factor of 5 to 200 Hz because of the SMPLRT_DIV setting 00267 00268 // Configure Interrupts and Bypass Enable 00269 // Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips 00270 // can join the I2C bus and all can be controlled by the Arduino as master 00271 00272 #if USE_ISR 00273 writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x12); // INT is 50 microsecond pulse and any read to clear 00274 #else 00275 writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x22); 00276 #endif 00277 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt 00278 } 00279 00280 // Function which accumulates gyro and accelerometer data after device initialization. It calculates the average 00281 // of the at-rest readings and then loads the resulting offsets into accelerometer and gyro bias registers. 00282 void MPU9250::calibrateMPU9250 (float * dest1, float * dest2) 00283 { 00284 uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data 00285 uint16_t ii, packet_count, fifo_count; 00286 int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0}; 00287 00288 // reset device, reset all registers, clear gyro and accelerometer bias registers 00289 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device 00290 wait(0.1); 00291 00292 // get stable time source 00293 // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001 00294 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01); 00295 writeByte(MPU9250_ADDRESS, PWR_MGMT_2, 0x00); 00296 wait(0.2); 00297 00298 // Configure device for bias calculation 00299 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts 00300 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable FIFO 00301 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source 00302 writeByte(MPU9250_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master 00303 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes 00304 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP 00305 wait(0.015); 00306 00307 // Configure MPU9250 gyro and accelerometer for bias calculation 00308 writeByte(MPU9250_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz 00309 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz 00310 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity 00311 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity 00312 00313 uint16_t gyrosensitivity = 131; // = 131 LSB/degrees/sec 00314 uint16_t accelsensitivity = 16384; // = 16384 LSB/g 00315 00316 // Configure FIFO to capture accelerometer and gyro data for bias calculation 00317 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x40); // Enable FIFO 00318 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9250) 00319 wait(0.04); // accumulate 40 samples in 80 milliseconds = 480 bytes 00320 00321 // At end of sample accumulation, turn off FIFO sensor read 00322 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO 00323 readBytes(MPU9250_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count 00324 fifo_count = ((uint16_t)data[0] << 8) | data[1]; 00325 packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging 00326 00327 for (ii = 0; ii < packet_count; ii++) { 00328 int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0}; 00329 readBytes(MPU9250_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging 00330 accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO 00331 accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ; 00332 accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ; 00333 gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ; 00334 gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ; 00335 gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ; 00336 00337 accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases 00338 accel_bias[1] += (int32_t) accel_temp[1]; 00339 accel_bias[2] += (int32_t) accel_temp[2]; 00340 gyro_bias[0] += (int32_t) gyro_temp[0]; 00341 gyro_bias[1] += (int32_t) gyro_temp[1]; 00342 gyro_bias[2] += (int32_t) gyro_temp[2]; 00343 00344 } 00345 accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases 00346 accel_bias[1] /= (int32_t) packet_count; 00347 accel_bias[2] /= (int32_t) packet_count; 00348 gyro_bias[0] /= (int32_t) packet_count; 00349 gyro_bias[1] /= (int32_t) packet_count; 00350 gyro_bias[2] /= (int32_t) packet_count; 00351 00352 if(accel_bias[2] > 0L) {accel_bias[2] -= (int32_t) accelsensitivity;} // Remove gravity from the z-axis accelerometer bias calculation 00353 else {accel_bias[2] += (int32_t) accelsensitivity;} 00354 00355 // Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup 00356 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 00357 data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases 00358 data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF; 00359 data[3] = (-gyro_bias[1]/4) & 0xFF; 00360 data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF; 00361 data[5] = (-gyro_bias[2]/4) & 0xFF; 00362 00363 /// Push gyro biases to hardware registers 00364 /* writeByte(MPU9250_ADDRESS, XG_OFFSET_H, data[0]); 00365 writeByte(MPU9250_ADDRESS, XG_OFFSET_L, data[1]); 00366 writeByte(MPU9250_ADDRESS, YG_OFFSET_H, data[2]); 00367 writeByte(MPU9250_ADDRESS, YG_OFFSET_L, data[3]); 00368 writeByte(MPU9250_ADDRESS, ZG_OFFSET_H, data[4]); 00369 writeByte(MPU9250_ADDRESS, ZG_OFFSET_L, data[5]); 00370 */ 00371 dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction 00372 dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity; 00373 dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity; 00374 00375 // Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain 00376 // factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold 00377 // non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature 00378 // compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that 00379 // the accelerometer biases calculated above must be divided by 8. 00380 00381 int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases 00382 readBytes(MPU9250_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values 00383 accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1]; 00384 readBytes(MPU9250_ADDRESS, YA_OFFSET_H, 2, &data[0]); 00385 accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1]; 00386 readBytes(MPU9250_ADDRESS, ZA_OFFSET_H, 2, &data[0]); 00387 accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1]; 00388 00389 uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers 00390 uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis 00391 00392 for(ii = 0; ii < 3; ii++) { 00393 if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit 00394 } 00395 00396 // Construct total accelerometer bias, including calculated average accelerometer bias from above 00397 accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale) 00398 accel_bias_reg[1] -= (accel_bias[1]/8); 00399 accel_bias_reg[2] -= (accel_bias[2]/8); 00400 00401 data[0] = (accel_bias_reg[0] >> 8) & 0xFF; 00402 data[1] = (accel_bias_reg[0]) & 0xFF; 00403 data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers 00404 data[2] = (accel_bias_reg[1] >> 8) & 0xFF; 00405 data[3] = (accel_bias_reg[1]) & 0xFF; 00406 data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers 00407 data[4] = (accel_bias_reg[2] >> 8) & 0xFF; 00408 data[5] = (accel_bias_reg[2]) & 0xFF; 00409 data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers 00410 00411 // Apparently this is not working for the acceleration biases in the MPU-9250 00412 // Are we handling the temperature correction bit properly? 00413 // Push accelerometer biases to hardware registers 00414 /* writeByte(MPU9250_ADDRESS, XA_OFFSET_H, data[0]); 00415 writeByte(MPU9250_ADDRESS, XA_OFFSET_L, data[1]); 00416 writeByte(MPU9250_ADDRESS, YA_OFFSET_H, data[2]); 00417 writeByte(MPU9250_ADDRESS, YA_OFFSET_L, data[3]); 00418 writeByte(MPU9250_ADDRESS, ZA_OFFSET_H, data[4]); 00419 writeByte(MPU9250_ADDRESS, ZA_OFFSET_L, data[5]); 00420 */ 00421 // Output scaled accelerometer biases for manual subtraction in the main program 00422 dest2[0] = (float)accel_bias[0]/(float)accelsensitivity; 00423 dest2[1] = (float)accel_bias[1]/(float)accelsensitivity; 00424 dest2[2] = (float)accel_bias[2]/(float)accelsensitivity; 00425 } 00426 00427 void MPU9250::magcalMPU9250(float * dest1, float * dest2) 00428 { 00429 uint16_t ii = 0, sample_count = 0; 00430 int32_t mag_bias[3] = {0, 0, 0}, mag_scale[3] = {0, 0, 0}; 00431 int16_t mag_max[3] = {-32767, -32767, -32767}, mag_min[3] = {32767, 32767, 32767}, mag_temp[3] = {0, 0, 0}; 00432 00433 // shoot for ~fifteen seconds of mag data 00434 if(Mmode == 0x02) sample_count = 128; // at 8 Hz ODR, new mag data is available every 125 ms 00435 if(Mmode == 0x06) sample_count = 1500; // at 100 Hz ODR, new mag data is available every 10 ms 00436 00437 for(ii = 0; ii < sample_count; ii++) { 00438 readMagData(mag_temp); // Read the mag data 00439 00440 for (int jj = 0; jj < 3; jj++) { 00441 if(mag_temp[jj] > mag_max[jj]) mag_max[jj] = mag_temp[jj]; 00442 if(mag_temp[jj] < mag_min[jj]) mag_min[jj] = mag_temp[jj]; 00443 } 00444 00445 if(Mmode == 0x02) wait(0.135); // at 8 Hz ODR, new mag data is available every 125 ms 00446 if(Mmode == 0x06) wait(0.012); // at 100 Hz ODR, new mag data is available every 10 ms 00447 } 00448 00449 // Get hard iron correction 00450 mag_bias[0] = (mag_max[0] + mag_min[0])/2; // get average x mag bias in counts 00451 mag_bias[1] = (mag_max[1] + mag_min[1])/2; // get average y mag bias in counts 00452 mag_bias[2] = (mag_max[2] + mag_min[2])/2; // get average z mag bias in counts 00453 00454 dest1[0] = (float) mag_bias[0]*mRes*magCalibration[0]; // save mag biases in G for main program 00455 dest1[1] = (float) mag_bias[1]*mRes*magCalibration[1]; 00456 dest1[2] = (float) mag_bias[2]*mRes*magCalibration[2]; 00457 00458 // Get soft iron correction estimate 00459 mag_scale[0] = (mag_max[0] - mag_min[0])/2; // get average x axis max chord length in counts 00460 mag_scale[1] = (mag_max[1] - mag_min[1])/2; // get average y axis max chord length in counts 00461 mag_scale[2] = (mag_max[2] - mag_min[2])/2; // get average z axis max chord length in counts 00462 00463 float avg_rad = mag_scale[0] + mag_scale[1] + mag_scale[2]; 00464 avg_rad /= 3.0; 00465 00466 dest2[0] = avg_rad/((float)mag_scale[0]); 00467 dest2[1] = avg_rad/((float)mag_scale[1]); 00468 dest2[2] = avg_rad/((float)mag_scale[2]); 00469 } 00470 00471 00472 // Accelerometer and gyroscope self test; check calibration wrt factory settings 00473 void MPU9250::MPU9250SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass 00474 { 00475 uint8_t rawData[6] = {0, 0, 0, 0, 0, 0}; 00476 uint8_t selfTest[6]; 00477 int32_t gAvg[3] = {0}, aAvg[3] = {0}, aSTAvg[3] = {0}, gSTAvg[3] = {0}; 00478 float factoryTrim[6]; 00479 uint8_t FS = 0; 00480 00481 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz 00482 writeByte(MPU9250_ADDRESS, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz 00483 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 1<<FS); // Set full scale range for the gyro to 250 dps 00484 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz 00485 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 1<<FS); // Set full scale range for the accelerometer to 2 g 00486 00487 for( int ii = 0; ii < 200; ii++) { // get average current values of gyro and acclerometer 00488 00489 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array 00490 aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value 00491 aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; 00492 aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 00493 00494 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array 00495 gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value 00496 gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; 00497 gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 00498 } 00499 00500 for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average current readings 00501 aAvg[ii] /= 200; 00502 gAvg[ii] /= 200; 00503 } 00504 00505 // Configure the accelerometer for self-test 00506 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g 00507 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s 00508 wait(0.025); // Delay a while to let the device stabilize 00509 00510 for( int ii = 0; ii < 200; ii++) { // get average self-test values of gyro and acclerometer 00511 00512 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array 00513 aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value 00514 aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; 00515 aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 00516 00517 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array 00518 gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value 00519 gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; 00520 gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 00521 } 00522 00523 for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average self-test readings 00524 aSTAvg[ii] /= 200; 00525 gSTAvg[ii] /= 200; 00526 } 00527 00528 // Configure the gyro and accelerometer for normal operation 00529 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); 00530 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); 00531 wait(0.025); // Delay a while to let the device stabilize 00532 00533 // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg 00534 selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results 00535 selfTest[1] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_ACCEL); // Y-axis accel self-test results 00536 selfTest[2] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_ACCEL); // Z-axis accel self-test results 00537 selfTest[3] = readByte(MPU9250_ADDRESS, SELF_TEST_X_GYRO); // X-axis gyro self-test results 00538 selfTest[4] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_GYRO); // Y-axis gyro self-test results 00539 selfTest[5] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_GYRO); // Z-axis gyro self-test results 00540 00541 // Retrieve factory self-test value from self-test code reads 00542 factoryTrim[0] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation 00543 factoryTrim[1] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation 00544 factoryTrim[2] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation 00545 factoryTrim[3] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation 00546 factoryTrim[4] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation 00547 factoryTrim[5] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation 00548 00549 // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response 00550 // To get percent, must multiply by 100 00551 for (int i = 0; i < 3; i++) { 00552 destination[i] = 100.0*((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i] - 100.; // Report percent differences 00553 destination[i+3] = 100.0*((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3] - 100.; // Report percent differences 00554 } 00555 00556 } 00557 00558 void MPU9250::MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz) 00559 { 00560 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability 00561 float norm; 00562 float hx, hy, _2bx, _2bz; 00563 float s1, s2, s3, s4; 00564 float qDot1, qDot2, qDot3, qDot4; 00565 00566 // Auxiliary variables to avoid repeated arithmetic 00567 float _2q1mx; 00568 float _2q1my; 00569 float _2q1mz; 00570 float _2q2mx; 00571 float _4bx; 00572 float _4bz; 00573 float _2q1 = 2.0f * q1; 00574 float _2q2 = 2.0f * q2; 00575 float _2q3 = 2.0f * q3; 00576 float _2q4 = 2.0f * q4; 00577 float _2q1q3 = 2.0f * q1 * q3; 00578 float _2q3q4 = 2.0f * q3 * q4; 00579 float q1q1 = q1 * q1; 00580 float q1q2 = q1 * q2; 00581 float q1q3 = q1 * q3; 00582 float q1q4 = q1 * q4; 00583 float q2q2 = q2 * q2; 00584 float q2q3 = q2 * q3; 00585 float q2q4 = q2 * q4; 00586 float q3q3 = q3 * q3; 00587 float q3q4 = q3 * q4; 00588 float q4q4 = q4 * q4; 00589 00590 // Normalise accelerometer measurement 00591 norm = sqrt(ax * ax + ay * ay + az * az); 00592 if (norm == 0.0f) return; // handle NaN 00593 norm = 1.0f/norm; 00594 ax *= norm; 00595 ay *= norm; 00596 az *= norm; 00597 00598 // Normalise magnetometer measurement 00599 norm = sqrt(mx * mx + my * my + mz * mz); 00600 if (norm == 0.0f) return; // handle NaN 00601 norm = 1.0f/norm; 00602 mx *= norm; 00603 my *= norm; 00604 mz *= norm; 00605 00606 // Reference direction of Earth's magnetic field 00607 _2q1mx = 2.0f * q1 * mx; 00608 _2q1my = 2.0f * q1 * my; 00609 _2q1mz = 2.0f * q1 * mz; 00610 _2q2mx = 2.0f * q2 * mx; 00611 hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4; 00612 hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4; 00613 _2bx = sqrt(hx * hx + hy * hy); 00614 _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4; 00615 _4bx = 2.0f * _2bx; 00616 _4bz = 2.0f * _2bz; 00617 00618 // Gradient decent algorithm corrective step 00619 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); 00620 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); 00621 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); 00622 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); 00623 norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4); // normalise step magnitude 00624 norm = 1.0f/norm; 00625 s1 *= norm; 00626 s2 *= norm; 00627 s3 *= norm; 00628 s4 *= norm; 00629 00630 // Compute rate of change of quaternion 00631 qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1; 00632 qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2; 00633 qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3; 00634 qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4; 00635 00636 // Integrate to yield quaternion 00637 q1 += qDot1 * deltat; 00638 q2 += qDot2 * deltat; 00639 q3 += qDot3 * deltat; 00640 q4 += qDot4 * deltat; 00641 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion 00642 norm = 1.0f/norm; 00643 q[0] = q1 * norm; 00644 q[1] = q2 * norm; 00645 q[2] = q3 * norm; 00646 q[3] = q4 * norm; 00647 00648 } 00649 00650 // Similar to Madgwick scheme but uses proportional and integral filtering on the error between estimated reference vectors and 00651 // measured ones. 00652 void MPU9250::MahonyQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz) 00653 { 00654 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability 00655 float norm; 00656 float hx, hy, bx, bz; 00657 float vx, vy, vz, wx, wy, wz; 00658 float ex, ey, ez; 00659 float pa, pb, pc; 00660 00661 // Auxiliary variables to avoid repeated arithmetic 00662 float q1q1 = q1 * q1; 00663 float q1q2 = q1 * q2; 00664 float q1q3 = q1 * q3; 00665 float q1q4 = q1 * q4; 00666 float q2q2 = q2 * q2; 00667 float q2q3 = q2 * q3; 00668 float q2q4 = q2 * q4; 00669 float q3q3 = q3 * q3; 00670 float q3q4 = q3 * q4; 00671 float q4q4 = q4 * q4; 00672 00673 // Normalise accelerometer measurement 00674 norm = sqrt(ax * ax + ay * ay + az * az); 00675 if (norm == 0.0f) return; // handle NaN 00676 norm = 1.0f / norm; // use reciprocal for division 00677 ax *= norm; 00678 ay *= norm; 00679 az *= norm; 00680 00681 // Normalise magnetometer measurement 00682 norm = sqrt(mx * mx + my * my + mz * mz); 00683 if (norm == 0.0f) return; // handle NaN 00684 norm = 1.0f / norm; // use reciprocal for division 00685 mx *= norm; 00686 my *= norm; 00687 mz *= norm; 00688 00689 // Reference direction of Earth's magnetic field 00690 hx = 2.0f * mx * (0.5f - q3q3 - q4q4) + 2.0f * my * (q2q3 - q1q4) + 2.0f * mz * (q2q4 + q1q3); 00691 hy = 2.0f * mx * (q2q3 + q1q4) + 2.0f * my * (0.5f - q2q2 - q4q4) + 2.0f * mz * (q3q4 - q1q2); 00692 bx = sqrt((hx * hx) + (hy * hy)); 00693 bz = 2.0f * mx * (q2q4 - q1q3) + 2.0f * my * (q3q4 + q1q2) + 2.0f * mz * (0.5f - q2q2 - q3q3); 00694 00695 // Estimated direction of gravity and magnetic field 00696 vx = 2.0f * (q2q4 - q1q3); 00697 vy = 2.0f * (q1q2 + q3q4); 00698 vz = q1q1 - q2q2 - q3q3 + q4q4; 00699 wx = 2.0f * bx * (0.5f - q3q3 - q4q4) + 2.0f * bz * (q2q4 - q1q3); 00700 wy = 2.0f * bx * (q2q3 - q1q4) + 2.0f * bz * (q1q2 + q3q4); 00701 wz = 2.0f * bx * (q1q3 + q2q4) + 2.0f * bz * (0.5f - q2q2 - q3q3); 00702 00703 // Error is cross product between estimated direction and measured direction of gravity 00704 ex = (ay * vz - az * vy) + (my * wz - mz * wy); 00705 ey = (az * vx - ax * vz) + (mz * wx - mx * wz); 00706 ez = (ax * vy - ay * vx) + (mx * wy - my * wx); 00707 if (Ki > 0.0f) 00708 { 00709 eInt[0] += ex; // accumulate integral error 00710 eInt[1] += ey; 00711 eInt[2] += ez; 00712 } 00713 else 00714 { 00715 eInt[0] = 0.0f; // prevent integral wind up 00716 eInt[1] = 0.0f; 00717 eInt[2] = 0.0f; 00718 } 00719 00720 // Apply feedback terms 00721 gx = gx + Kp * ex + Ki * eInt[0]; 00722 gy = gy + Kp * ey + Ki * eInt[1]; 00723 gz = gz + Kp * ez + Ki * eInt[2]; 00724 00725 // Integrate rate of change of quaternion 00726 pa = q2; 00727 pb = q3; 00728 pc = q4; 00729 q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * deltat); 00730 q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * deltat); 00731 q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * deltat); 00732 q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * deltat); 00733 00734 // Normalise quaternion 00735 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); 00736 norm = 1.0f / norm; 00737 q[0] = q1 * norm; 00738 q[1] = q2 * norm; 00739 q[2] = q3 * norm; 00740 q[3] = q4 * norm; 00741 00742 } 00743
Generated on Thu Jul 14 2022 23:17:31 by
1.7.2