航空研究会
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MPU9255_ver1
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MPU9255.cpp
00001 #include"MPU9255.h" 00002 00003 //----------------- 00004 //private functions 00005 //----------------- 00006 00007 void MPU9255::writeByte(uint8_t address, uint8_t subAddress, uint8_t data) 00008 { 00009 char data_write[2]; 00010 data_write[0] = subAddress; 00011 data_write[1] = data; 00012 i2c.write(address, data_write, 2, 0); 00013 } 00014 00015 char MPU9255::readByte(uint8_t address, uint8_t subAddress) 00016 { 00017 char data[1]; // `data` will store the register data 00018 char data_write[1]; 00019 data_write[0] = subAddress; 00020 i2c.write(address, data_write, 1, 1); // no stop 00021 i2c.read(address, data, 1, 0); 00022 return data[0]; 00023 } 00024 00025 void MPU9255::readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest) 00026 { 00027 char data[14]; 00028 char data_write[1]; 00029 data_write[0] = subAddress; 00030 i2c.write(address, data_write, 1, 1); // no stop 00031 i2c.read(address, data, count, 0); 00032 for(int ii = 0; ii < count; ii++) 00033 { 00034 dest[ii] = data[ii]; 00035 } 00036 } 00037 00038 00039 //---------------- 00040 //public functions 00041 //---------------- 00042 00043 MPU9255::MPU9255(PinName sda, PinName scl, RawSerial* serial_p) 00044 : i2c_p(new I2C(sda,scl)), i2c(*i2c_p), pc_p(serial_p) 00045 { 00046 i2c.frequency(40000); 00047 } 00048 00049 MPU9255::~MPU9255() {} 00050 00051 uint8_t MPU9255::whoami_mpu9255() 00052 { 00053 uint8_t a = readByte(MPU9255_ADDRESS, WHO_AM_I_MPU9255); 00054 return a; 00055 } 00056 00057 void MPU9255::reset_mpu9255() 00058 { 00059 writeByte(MPU9255_ADDRESS, PWR_MGMT_1, 0x80); 00060 wait_ms(10); 00061 } 00062 00063 void MPU9255::selftest_mpu9255(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass 00064 { 00065 uint8_t rawData[6] = {0, 0, 0, 0, 0, 0}; 00066 uint8_t selfTest[6]; 00067 int32_t gAvg[3] = {0}, aAvg[3] = {0}, aSTAvg[3] = {0}, gSTAvg[3] = {0}; 00068 float factoryTrim[6]; 00069 uint8_t FS = 0; 00070 00071 writeByte(MPU9255_ADDRESS, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz 00072 writeByte(MPU9255_ADDRESS, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz 00073 writeByte(MPU9255_ADDRESS, GYRO_CONFIG, 1<<FS); // Set full scale range for the gyro to 250 dps 00074 writeByte(MPU9255_ADDRESS, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz 00075 writeByte(MPU9255_ADDRESS, ACCEL_CONFIG, 1<<FS); // Set full scale range for the accelerometer to 2 g 00076 00077 for( int ii = 0; ii < 200; ii++) // get average current values of gyro and acclerometer 00078 { 00079 readBytes(MPU9255_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array 00080 aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value 00081 aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; 00082 aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 00083 00084 readBytes(MPU9255_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array 00085 gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value 00086 gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; 00087 gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 00088 } 00089 00090 for (int ii =0; ii < 3; ii++) // Get average of 200 values and store as average current readings 00091 { 00092 aAvg[ii] /= 200; 00093 gAvg[ii] /= 200; 00094 } 00095 00096 // Configure the accelerometer for self-test 00097 writeByte(MPU9255_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g 00098 writeByte(MPU9255_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s 00099 wait_ms(25); // Delay a while to let the device stabilize 00100 00101 for( int ii = 0; ii < 200; ii++) // get average self-test values of gyro and acclerometer 00102 { 00103 readBytes(MPU9255_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array 00104 aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value 00105 aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; 00106 aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 00107 00108 readBytes(MPU9255_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array 00109 gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value 00110 gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; 00111 gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 00112 } 00113 00114 for (int ii =0; ii < 3; ii++) // Get average of 200 values and store as average self-test readings 00115 { 00116 aSTAvg[ii] /= 200; 00117 gSTAvg[ii] /= 200; 00118 } 00119 00120 // Configure the gyro and accelerometer for normal operation 00121 writeByte(MPU9255_ADDRESS, ACCEL_CONFIG, 0x00); 00122 writeByte(MPU9255_ADDRESS, GYRO_CONFIG, 0x00); 00123 wait_ms(25); // Delay a while to let the device stabilize 00124 00125 // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg 00126 selfTest[0] = readByte(MPU9255_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results 00127 selfTest[1] = readByte(MPU9255_ADDRESS, SELF_TEST_Y_ACCEL); // Y-axis accel self-test results 00128 selfTest[2] = readByte(MPU9255_ADDRESS, SELF_TEST_Z_ACCEL); // Z-axis accel self-test results 00129 selfTest[3] = readByte(MPU9255_ADDRESS, SELF_TEST_X_GYRO); // X-axis gyro self-test results 00130 selfTest[4] = readByte(MPU9255_ADDRESS, SELF_TEST_Y_GYRO); // Y-axis gyro self-test results 00131 selfTest[5] = readByte(MPU9255_ADDRESS, SELF_TEST_Z_GYRO); // Z-axis gyro self-test results 00132 00133 // Retrieve factory self-test value from self-test code reads 00134 factoryTrim[0] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation 00135 factoryTrim[1] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation 00136 factoryTrim[2] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation 00137 factoryTrim[3] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation 00138 factoryTrim[4] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation 00139 factoryTrim[5] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation 00140 00141 // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response 00142 // To get percent, must multiply by 100 00143 for (int i = 0; i < 3; i++) 00144 { 00145 destination[i] = 100.0f*((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i] - 100.0f; // Report percent differences 00146 destination[i+3] = 100.0f*((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3] - 100.0f; // Report percent differences 00147 } 00148 00149 } 00150 00151 float MPU9255::getMres(uint8_t Mscale) 00152 { 00153 float _mRes; 00154 switch (Mscale) 00155 { 00156 // Possible magnetometer scales (and their register bit settings) are: 00157 // 14 bit resolution (0) and 16 bit resolution (1) 00158 case MFS_14BITS: 00159 _mRes = 10.*4912./8190.; // Proper scale to return milliGauss 00160 return _mRes; 00161 //break; 00162 case MFS_16BITS: 00163 _mRes = 10.*4912./32760.0; // Proper scale to return milliGauss (4912/32760=0.15) 00164 return _mRes; // convert 'μT' to 'mG' 00165 //break; 00166 } 00167 } 00168 00169 float MPU9255::getGres(uint8_t Gscale) 00170 { 00171 float _gRes; 00172 switch (Gscale) 00173 { 00174 // Possible gyro scales (and their register bit settings) are: 00175 // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS (11). 00176 case GFS_250DPS: 00177 _gRes = 250.0/32768.0; 00178 return _gRes; 00179 //break; 00180 case GFS_500DPS: 00181 _gRes = 500.0/32768.0; 00182 return _gRes; 00183 //break; 00184 case GFS_1000DPS: 00185 _gRes = 1000.0/32768.0; 00186 return _gRes; 00187 //break; 00188 case GFS_2000DPS: 00189 _gRes = 2000.0/32768.0; 00190 return _gRes; 00191 //break; 00192 } 00193 } 00194 00195 float MPU9255::getAres(uint8_t Ascale) 00196 { 00197 float _aRes; 00198 switch (Ascale) 00199 { 00200 // Possible accelerometer scales (and their register bit settings) are: 00201 // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs (11). 00202 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value: 00203 case AFS_2G: 00204 _aRes = 2.0f/32768.0f; 00205 return _aRes; 00206 //break; 00207 case AFS_4G: 00208 _aRes = 4.0f/32768.0f; 00209 return _aRes; 00210 //break; 00211 case AFS_8G: 00212 _aRes = 8.0f/32768.0f; 00213 return _aRes; 00214 //break; 00215 case AFS_16G: 00216 _aRes = 16.0f/32768.0f; 00217 return _aRes; 00218 //break; 00219 } 00220 } 00221 00222 void MPU9255::calibrate_mpu9255(float * dest1, float * dest2) 00223 { 00224 uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data 00225 uint16_t ii, packet_count, fifo_count; 00226 int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0}; 00227 00228 // reset device 00229 writeByte(MPU9255_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device 00230 wait_ms(100); 00231 00232 // get stable time source; Auto select clock source to be PLL gyroscope reference if ready 00233 // else use the internal oscillator, bits 2:0 = 001 00234 writeByte(MPU9255_ADDRESS, PWR_MGMT_1, 0x01); 00235 writeByte(MPU9255_ADDRESS, PWR_MGMT_2, 0x00); 00236 wait_ms(200); 00237 00238 // Configure device for bias calculation 00239 writeByte(MPU9255_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts 00240 writeByte(MPU9255_ADDRESS, FIFO_EN, 0x00); // Disable FIFO 00241 writeByte(MPU9255_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source 00242 writeByte(MPU9255_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master 00243 writeByte(MPU9255_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes 00244 writeByte(MPU9255_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP 00245 wait_ms(15); 00246 00247 // Configure MPU6050 gyro and accelerometer for bias calculation 00248 writeByte(MPU9255_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz 00249 writeByte(MPU9255_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz 00250 writeByte(MPU9255_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity 00251 writeByte(MPU9255_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity 00252 00253 uint16_t gyrosensitivity = 131; // = 131 LSB/degrees/sec 00254 uint16_t accelsensitivity = 16384; // = 16384 LSB/g 00255 00256 // Configure FIFO to capture accelerometer and gyro data for bias calculation 00257 writeByte(MPU9255_ADDRESS, USER_CTRL, 0x40); // Enable FIFO 00258 writeByte(MPU9255_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9150) 00259 wait_ms(40); // accumulate 40 samples in 40 milliseconds = 480 bytes 00260 00261 // At end of sample accumulation, turn off FIFO sensor read 00262 writeByte(MPU9255_ADDRESS, FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO 00263 readBytes(MPU9255_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count 00264 fifo_count = ((uint16_t)data[0] << 8) | data[1]; 00265 packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging 00266 00267 for (ii = 0; ii < packet_count; ii++) 00268 { 00269 int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0}; 00270 readBytes(MPU9255_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging 00271 accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO 00272 accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ; 00273 accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ; 00274 gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ; 00275 gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ; 00276 gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ; 00277 00278 accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases 00279 accel_bias[1] += (int32_t) accel_temp[1]; 00280 accel_bias[2] += (int32_t) accel_temp[2]; 00281 gyro_bias[0] += (int32_t) gyro_temp[0]; 00282 gyro_bias[1] += (int32_t) gyro_temp[1]; 00283 gyro_bias[2] += (int32_t) gyro_temp[2]; 00284 00285 } 00286 00287 accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases 00288 accel_bias[1] /= (int32_t) packet_count; 00289 accel_bias[2] /= (int32_t) packet_count; 00290 gyro_bias[0] /= (int32_t) packet_count; 00291 gyro_bias[1] /= (int32_t) packet_count; 00292 gyro_bias[2] /= (int32_t) packet_count; 00293 00294 if(accel_bias[2] > 0L) {accel_bias[2] -= (int32_t) accelsensitivity;} // Remove gravity from the z-axis accelerometer bias calculation 00295 else {accel_bias[2] += (int32_t) accelsensitivity;} 00296 00297 // Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup 00298 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 00299 data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases 00300 data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF; 00301 data[3] = (-gyro_bias[1]/4) & 0xFF; 00302 data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF; 00303 data[5] = (-gyro_bias[2]/4) & 0xFF; 00304 00305 // Push gyro biases to hardware registers 00306 writeByte(MPU9255_ADDRESS, XG_OFFSET_H, data[0]); 00307 writeByte(MPU9255_ADDRESS, XG_OFFSET_L, data[1]); 00308 writeByte(MPU9255_ADDRESS, YG_OFFSET_H, data[2]); 00309 writeByte(MPU9255_ADDRESS, YG_OFFSET_L, data[3]); 00310 writeByte(MPU9255_ADDRESS, ZG_OFFSET_H, data[4]); 00311 writeByte(MPU9255_ADDRESS, ZG_OFFSET_L, data[5]); 00312 00313 // Output scaled gyro biases for display in the main program 00314 dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; 00315 dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity; 00316 dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity; 00317 00318 // Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain 00319 // factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold 00320 // non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature 00321 // compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that 00322 // the accelerometer biases calculated above must be divided by 8. 00323 00324 int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases 00325 readBytes(MPU9255_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values 00326 accel_bias_reg[0] = (int32_t) (((int16_t)data[0] << 8) | data[1]); 00327 readBytes(MPU9255_ADDRESS, YA_OFFSET_H, 2, &data[0]); 00328 accel_bias_reg[1] = (int32_t) (((int16_t)data[0] << 8) | data[1]); 00329 readBytes(MPU9255_ADDRESS, ZA_OFFSET_H, 2, &data[0]); 00330 accel_bias_reg[2] = (int32_t) (((int16_t)data[0] << 8) | data[1]); 00331 00332 uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers 00333 uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis 00334 00335 for(ii = 0; ii < 3; ii++) 00336 { 00337 if((accel_bias_reg[ii] & mask)) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit 00338 } 00339 00340 // Construct total accelerometer bias, including calculated average accelerometer bias from above 00341 accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale) 00342 accel_bias_reg[1] -= (accel_bias[1]/8); 00343 accel_bias_reg[2] -= (accel_bias[2]/8); 00344 00345 data[0] = (accel_bias_reg[0] >> 8) & 0xFF; 00346 data[1] = (accel_bias_reg[0]) & 0xFF; 00347 data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers 00348 data[2] = (accel_bias_reg[1] >> 8) & 0xFF; 00349 data[3] = (accel_bias_reg[1]) & 0xFF; 00350 data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers 00351 data[4] = (accel_bias_reg[2] >> 8) & 0xFF; 00352 data[5] = (accel_bias_reg[2]) & 0xFF; 00353 data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers 00354 00355 // Apparently this is not working for the acceleration biases in the MPU-9255 00356 // Are we handling the temperature correction bit properly? 00357 // Push accelerometer biases to hardware registers 00358 // writeByte(MPU9255_ADDRESS, XA_OFFSET_H, data[0]); 00359 // writeByte(MPU9255_ADDRESS, XA_OFFSET_L, data[1]); 00360 // writeByte(MPU9255_ADDRESS, YA_OFFSET_H, data[2]); 00361 // writeByte(MPU9255_ADDRESS, YA_OFFSET_L, data[3]); 00362 // writeByte(MPU9255_ADDRESS, ZA_OFFSET_H, data[4]); 00363 // writeByte(MPU9255_ADDRESS, ZA_OFFSET_L, data[5]); 00364 00365 // Output scaled accelerometer biases for display in the main program 00366 dest2[0] = (float)accel_bias[0]/(float)accelsensitivity; 00367 dest2[1] = (float)accel_bias[1]/(float)accelsensitivity; 00368 dest2[2] = (float)accel_bias[2]/(float)accelsensitivity; 00369 } 00370 00371 void MPU9255::init_mpu9255(uint8_t Ascale, uint8_t Gscale, uint8_t sampleRate) 00372 { 00373 // wake up device 00374 writeByte(MPU9255_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors 00375 wait_ms(100); // Wait for all registers to reset 00376 00377 // get stable time source 00378 writeByte(MPU9255_ADDRESS, PWR_MGMT_1, 0x01); // Auto select clock source to be PLL gyroscope reference if ready else 00379 wait_ms(200); 00380 00381 // Configure Gyro and Thermometer 00382 // Disable FSYNC and set thermometer and gyro bandwidth to 41 and 42 Hz, respectively; 00383 // minimum delay time for this setting is 5.9 ms, which means sensor fusion update rates cannot 00384 // be higher than 1 / 0.0059 = 170 Hz 00385 // DLPF_CFG = bits 2:0 = 011; this limits the sample rate to 1000 Hz for both 00386 // With the MPU9255, it is possible to get gyro sample rates of 32 kHz (!), 8 kHz, or 1 kHz 00387 writeByte(MPU9255_ADDRESS, CONFIG, 0x03); 00388 00389 // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV) 00390 writeByte(MPU9255_ADDRESS, SMPLRT_DIV, sampleRate); // Use a 200 Hz rate; a rate consistent with the filter update rate 00391 // determined inset in CONFIG above 00392 00393 // Set gyroscope full scale range 00394 // Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3 00395 uint8_t c = readByte(MPU9255_ADDRESS, GYRO_CONFIG); // get current GYRO_CONFIG register value 00396 // c = c & ~0xE0; // Clear self-test bits [7:5] 00397 c = c & ~0x02; // Clear Fchoice bits [1:0] 00398 c = c & ~0x18; // Clear AFS bits [4:3] 00399 c = c | Gscale << 3; // Set full scale range for the gyro 00400 // c =| 0x00; // Set Fchoice for the gyro to 11 by writing its inverse to bits 1:0 of GYRO_CONFIG 00401 writeByte(MPU9255_ADDRESS, GYRO_CONFIG, c ); // Write new GYRO_CONFIG value to register 00402 00403 // Set accelerometer full-scale range configuration 00404 c = readByte(MPU9255_ADDRESS, ACCEL_CONFIG); // get current ACCEL_CONFIG register value 00405 // c = c & ~0xE0; // Clear self-test bits [7:5] 00406 c = c & ~0x18; // Clear AFS bits [4:3] 00407 c = c | Ascale << 3; // Set full scale range for the accelerometer 00408 writeByte(MPU9255_ADDRESS, ACCEL_CONFIG, c); // Write new ACCEL_CONFIG register value 00409 00410 // Set accelerometer sample rate configuration 00411 // It is possible to get a 4 kHz sample rate from the accelerometer by choosing 1 for 00412 // accel_fchoice_b bit [3]; in this case the bandwidth is 1.13 kHz 00413 c = readByte(MPU9255_ADDRESS, ACCEL_CONFIG2); // get current ACCEL_CONFIG2 register value 00414 c = c & ~0x0F; // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0]) 00415 c = c | 0x03; // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz 00416 writeByte(MPU9255_ADDRESS, ACCEL_CONFIG2, c); // Write new ACCEL_CONFIG2 register value 00417 00418 // The accelerometer, gyro, and thermometer are set to 1 kHz sample rates, 00419 // but all these rates are further reduced by a factor of 5 to 200 Hz because of the SMPLRT_DIV setting 00420 00421 // Configure Interrupts and Bypass Enable 00422 // Set interrupt pin active high, push-pull, hold interrupt pin level HIGH until interrupt cleared, 00423 // clear on read of INT_STATUS, and enable I2C_BYPASS_EN so additional chips 00424 // can join the I2C bus and all can be controlled by the Arduino as master 00425 writeByte(MPU9255_ADDRESS, INT_PIN_CFG, 0x10); // INT is 50 microsecond pulse and any read to clear 00426 writeByte(MPU9255_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt 00427 wait_ms(100); 00428 00429 writeByte(MPU9255_ADDRESS, USER_CTRL, 0x20); // Enable I2C Master mode 00430 writeByte(MPU9255_ADDRESS, I2C_MST_CTRL, 0x1D); // I2C configuration STOP after each transaction, master I2C bus at 400 KHz 00431 writeByte(MPU9255_ADDRESS, I2C_MST_DELAY_CTRL, 0x81); // Use blocking data retreival and enable delay for mag sample rate mismatch 00432 writeByte(MPU9255_ADDRESS, I2C_SLV4_CTRL, 0x01); // Delay mag data retrieval to once every other accel/gyro data sample 00433 } 00434 00435 00436 uint8_t MPU9255::get_AK8963CID() 00437 { 00438 writeByte(MPU9255_ADDRESS, USER_CTRL, 0x20); // Enable I2C Master mode 00439 writeByte(MPU9255_ADDRESS, I2C_MST_CTRL, 0x0D); // I2C configuration multi-master I2C 400KHz 00440 00441 writeByte(MPU9255_ADDRESS, I2C_SLV0_ADDR, AK8963_ADDRESS | 0x80); // Set the I2C slave address of AK8963 and set for read. 00442 writeByte(MPU9255_ADDRESS, I2C_SLV0_REG, WHO_AM_I_AK8963); // I2C slave 0 register address from where to begin data transfer 00443 writeByte(MPU9255_ADDRESS, I2C_SLV0_CTRL, 0x81); // Enable I2C and transfer 1 byte 00444 wait_ms(10); 00445 uint8_t c = readByte(MPU9255_ADDRESS, EXT_SENS_DATA_00); // Read the WHO_AM_I byte 00446 return c; 00447 } 00448 00449 void MPU9255::init_AK8963Slave(uint8_t Mscale, uint8_t Mmode, float * magCalibration) 00450 { 00451 // First extract the factory calibration for each magnetometer axis 00452 uint8_t rawData[3]; // x/y/z gyro calibration data stored here 00453 00454 writeByte(MPU9255_ADDRESS, I2C_SLV0_ADDR, AK8963_ADDRESS); // Set the I2C slave address of AK8963 and set for write. 00455 writeByte(MPU9255_ADDRESS, I2C_SLV0_REG, AK8963_CNTL2); // I2C slave 0 register address from where to begin data transfer 00456 writeByte(MPU9255_ADDRESS, I2C_SLV0_DO, 0x01); // Reset AK8963 00457 writeByte(MPU9255_ADDRESS, I2C_SLV0_CTRL, 0x81); // Enable I2C and write 1 byte 00458 wait_ms(50); 00459 writeByte(MPU9255_ADDRESS, I2C_SLV0_ADDR, AK8963_ADDRESS); // Set the I2C slave address of AK8963 and set for write. 00460 writeByte(MPU9255_ADDRESS, I2C_SLV0_REG, AK8963_CNTL); // I2C slave 0 register address from where to begin data transfer 00461 writeByte(MPU9255_ADDRESS, I2C_SLV0_DO, 0x00); // Power down magnetometer 00462 writeByte(MPU9255_ADDRESS, I2C_SLV0_CTRL, 0x81); // Enable I2C and write 1 byte 00463 wait_ms(50); 00464 writeByte(MPU9255_ADDRESS, I2C_SLV0_ADDR, AK8963_ADDRESS); // Set the I2C slave address of AK8963 and set for write. 00465 writeByte(MPU9255_ADDRESS, I2C_SLV0_REG, AK8963_CNTL); // I2C slave 0 register address from where to begin data transfer 00466 writeByte(MPU9255_ADDRESS, I2C_SLV0_DO, 0x0F); // Enter fuze mode 00467 writeByte(MPU9255_ADDRESS, I2C_SLV0_CTRL, 0x81); // Enable I2C and write 1 byte 00468 wait_ms(50); 00469 00470 writeByte(MPU9255_ADDRESS, I2C_SLV0_ADDR, AK8963_ADDRESS | 0x80); // Set the I2C slave address of AK8963 and set for read. 00471 writeByte(MPU9255_ADDRESS, I2C_SLV0_REG, AK8963_ASAX); // I2C slave 0 register address from where to begin data transfer 00472 writeByte(MPU9255_ADDRESS, I2C_SLV0_CTRL, 0x83); // Enable I2C and read 3 bytes 00473 wait_ms(50); 00474 readBytes(MPU9255_ADDRESS, EXT_SENS_DATA_00, 3, &rawData[0]); // Read the x-, y-, and z-axis calibration values 00475 magCalibration[0] = (float)(rawData[0] - 128)/256.0f + 1.0f; // Return x-axis sensitivity adjustment values, etc. 00476 magCalibration[1] = (float)(rawData[1] - 128)/256.0f + 1.0f; 00477 magCalibration[2] = (float)(rawData[2] - 128)/256.0f + 1.0f; 00478 /*_magCalibration[0] = magCalibration[0]; 00479 _magCalibration[1] = magCalibration[1]; 00480 _magCalibration[2] = magCalibration[2]; 00481 _Mmode = Mmode;*/ 00482 00483 writeByte(MPU9255_ADDRESS, I2C_SLV0_ADDR, AK8963_ADDRESS); // Set the I2C slave address of AK8963 and set for write. 00484 writeByte(MPU9255_ADDRESS, I2C_SLV0_REG, AK8963_CNTL); // I2C slave 0 register address from where to begin data transfer 00485 writeByte(MPU9255_ADDRESS, I2C_SLV0_DO, 0x00); // Power down magnetometer 00486 writeByte(MPU9255_ADDRESS, I2C_SLV0_CTRL, 0x81); // Enable I2C and transfer 1 byte 00487 wait_ms(50); 00488 00489 writeByte(MPU9255_ADDRESS, I2C_SLV0_ADDR, AK8963_ADDRESS); // Set the I2C slave address of AK8963 and set for write. 00490 writeByte(MPU9255_ADDRESS, I2C_SLV0_REG, AK8963_CNTL); // I2C slave 0 register address from where to begin data transfer 00491 // Configure the magnetometer for continuous read and highest resolution 00492 // set Mscale bit 4 to 1 (0) to enable 16 (14) bit resolution in CNTL register, 00493 // and enable continuous mode data acquisition Mmode (bits [3:0]), 0010 for 8 Hz and 0110 for 100 Hz sample rates 00494 writeByte(MPU9255_ADDRESS, I2C_SLV0_DO, Mscale << 4 | Mmode); // Set magnetometer data resolution and sample ODR 00495 writeByte(MPU9255_ADDRESS, I2C_SLV0_CTRL, 0x81); // Enable I2C and transfer 1 byte 00496 wait_ms(50); 00497 writeByte(MPU9255_ADDRESS, I2C_SLV0_ADDR, AK8963_ADDRESS | 0x80); // Set the I2C slave address of AK8963 and set for read. 00498 writeByte(MPU9255_ADDRESS, I2C_SLV0_REG, AK8963_CNTL); // I2C slave 0 register address from where to begin data transfer 00499 writeByte(MPU9255_ADDRESS, I2C_SLV0_CTRL, 0x81); // Enable I2C and transfer 1 byte 00500 wait_ms(50); 00501 } 00502 00503 void MPU9255::readMagData_mpu9255(int16_t * destination) 00504 { 00505 uint8_t rawData[7]; // x/y/z gyro register data, ST2 register stored here, must read ST2 at end of data acquisition 00506 // readBytes(AK8963_ADDRESS, AK8963_XOUT_L, 7, &rawData[0]); // Read the six raw data and ST2 registers sequentially into data array 00507 writeByte(MPU9255_ADDRESS, I2C_SLV0_ADDR, AK8963_ADDRESS | 0x80); // Set the I2C slave address of AK8963 and set for read. 00508 writeByte(MPU9255_ADDRESS, I2C_SLV0_REG, AK8963_XOUT_L); // I2C slave 0 register address from where to begin data transfer 00509 writeByte(MPU9255_ADDRESS, I2C_SLV0_CTRL, 0x87); // Enable I2C and read 7 bytes 00510 wait_ms(2); 00511 readBytes(MPU9255_ADDRESS, EXT_SENS_DATA_00, 7, &rawData[0]); // Read the x-, y-, and z-axis calibration values 00512 uint8_t c = rawData[6]; // End data read by reading ST2 register 00513 if(!(c & 0x08)) // Check if magnetic sensor overflow set, if not then report data 00514 { 00515 destination[0] = ((int16_t)rawData[1] << 8) | rawData[0] ; // Turn the MSB and LSB into a signed 16-bit value 00516 destination[1] = ((int16_t)rawData[3] << 8) | rawData[2] ; // Data stored as little Endian 00517 destination[2] = ((int16_t)rawData[5] << 8) | rawData[4] ; 00518 } 00519 } 00520 00521 void MPU9255::readaccgyrodata_mpu9255(int16_t * destination) 00522 { 00523 uint8_t rawData[14]; // x/y/z accel register data stored here 00524 readBytes(MPU9255_ADDRESS, ACCEL_XOUT_H, 14, &rawData[0]); // Read the 14 raw data registers into data array 00525 destination[0] = ((int16_t)rawData[0] << 8) | rawData[1] ; // Turn the MSB and LSB into a signed 16-bit value 00526 destination[1] = ((int16_t)rawData[2] << 8) | rawData[3] ; 00527 destination[2] = ((int16_t)rawData[4] << 8) | rawData[5] ; 00528 destination[3] = ((int16_t)rawData[6] << 8) | rawData[7] ; 00529 destination[4] = ((int16_t)rawData[8] << 8) | rawData[9] ; 00530 destination[5] = ((int16_t)rawData[10] << 8) | rawData[11] ; 00531 destination[6] = ((int16_t)rawData[12] << 8) | rawData[13] ; 00532 }
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