MPU6050.h

00001 #ifndef MPU6050_H
00002 #define MPU6050_H
00003 
00004 #include "mbed.h"
00005 
00006 /** MPU6050
00007  *
00008  * 三軸加速度&ジャイロセンサー
00009  * 説明用に最低限のドキュメントを作成
00010  */
00011 class MPU6050
00012 {
00013 protected:
00014 
00015 public:
00016     // Set initial input parameters
00017     enum Ascale {
00018         AFS_2G = 0,
00019         AFS_4G,
00020         AFS_8G,
00021         AFS_16G
00022     };
00023 
00024     enum Gscale {
00025         GFS_250DPS = 0,
00026         GFS_500DPS,
00027         GFS_1000DPS,
00028         GFS_2000DPS
00029     };
00030 
00031 //===================================================================================================================
00032 //====== Set of useful function to access acceleratio, gyroscope, and temperature data
00033 //===================================================================================================================
00034     /** センサの初期設定をする宣言
00035     * @param 12c_sda SDAをつないだピン名
00036     * @param i2c_scl SCLをつないだピン名
00037     * @param adO AD0ピンがhighとlowのどちらになっているか、普通は書かなくてもよい
00038     */
00039     MPU6050( PinName i2c_sda, PinName i2c_scl, int ad0 = 0)
00040     : i2c_p( new I2C( i2c_sda, i2c_scl ) ), i2c( *i2c_p ) {
00041 
00042         // Using the GY-521 breakout board, I set ADO to 0 by grounding through a 4k7 resistor
00043         // Seven-bit device address is 110100 for ADO = 0 and 110101 for ADO = 1
00044         if(ad0 == 0) {
00045             adr = 0x68 << 1;
00046         } else {
00047             adr = 0x69 << 1;
00048         }
00049 
00050         // Specify sensor full scale
00051         _Gscale = GFS_250DPS;
00052         _Ascale = AFS_2G;
00053 
00054         _q[0] = 1.0f;
00055         _q[1] = 0.0f;
00056         _q[2] = 0.0f;
00057         _q[3] = 0.0f;
00058         deltat = 0.0f;
00059 
00060         // parameters for 6 DoF sensor fusion calculations
00061         float PI = 3.14159265358979323846f;
00062         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
00063         beta = sqrt(3.0f / 4.0f) * GyroMeasError;  // compute beta
00064         float GyroMeasDrift = PI * (1.0f / 180.0f);      // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
00065         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
00066 
00067         float gyroBias[3] = {0, 0, 0}, accelBias[3] = {0, 0, 0}; // Bias corrections for gyro and accelerometer
00068         float SelfTest[6];
00069 
00070         MPU6050SelfTest(SelfTest);
00071         resetMPU6050();
00072         calibrateMPU6050(gyroBias, accelBias);
00073         initMPU6050();
00074     }
00075 
00076     // scale resolutions per LSB for the sensors
00077     float getGres() {
00078         float gRes;
00079         switch (_Gscale) {
00080                 // Possible gyro scales (and their register bit settings) are:
00081                 // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS  (11).
00082                 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
00083             case GFS_250DPS:
00084                 gRes = 250.0/32768.0;
00085                 break;
00086             case GFS_500DPS:
00087                 gRes = 500.0/32768.0;
00088                 break;
00089             case GFS_1000DPS:
00090                 gRes = 1000.0/32768.0;
00091                 break;
00092             case GFS_2000DPS:
00093                 gRes = 2000.0/32768.0;
00094                 break;
00095         }
00096         return gRes;
00097     }
00098 
00099     float getAres() {
00100         float aRes;
00101         switch (_Ascale) {
00102                 // Possible accelerometer scales (and their register bit settings) are:
00103                 // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs  (11).
00104                 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
00105             case AFS_2G:
00106                 aRes = 2.0/32768.0;
00107                 break;
00108             case AFS_4G:
00109                 aRes = 4.0/32768.0;
00110                 break;
00111             case AFS_8G:
00112                 aRes = 8.0/32768.0;
00113                 break;
00114             case AFS_16G:
00115                 aRes = 16.0/32768.0;
00116                 break;
00117         }
00118         return aRes;
00119     }
00120 
00121 
00122     void readAccelData (int * destination) { 
00123         /** 加速度の読み出し
00124          *  @param destination int[3]の配列を渡してください、加速度をxyz順に返します
00125          */
00126         uint8_t rawData[6];  // x/y/z accel register data stored here
00127         readBytes(ACCEL_XOUT_H, 6, &rawData[0]);  //(格納されているアドレス,データの長さ,格納するアドレス) Read the six raw data registers into data array
00128         destination[0] = (int)(((int8_t)rawData[0] << 8) | rawData[1]) ;  // 受信の順番では上位8ビットと下位8ビットが逆になっているので，交換してやる必要がある。Turn the MSB and LSB into a signed 16-bit value
00129         destination[1] = (int)(((int8_t)rawData[2] << 8) | rawData[3]) ;
00130         destination[2] = (int)(((int8_t)rawData[4] << 8) | rawData[5]) ;
00131     }
00132 
00133     void readGyroData (int * destination) {
00134         /** 角速度の読み出し
00135          *  @param destination int[3]の配列を渡してください、角速度をxyz順に返します
00136          */
00137         uint8_t rawData[6];  // x/y/z gyro register data stored here
00138         readBytes(GYRO_XOUT_H, 6, &rawData[0]);  // Read the six raw data registers sequentially into data array
00139         destination[0] = (int)(((int8_t)rawData[0] << 8) | rawData[1]) ;  // 最上位ビットと最下位ビットを符号付16ビットに変換
00140         destination[1] = (int)(((int8_t)rawData[2] << 8) | rawData[3]) ;
00141         destination[2] = (int)(((int8_t)rawData[4] << 8) | rawData[5]) ;
00142     }
00143 
00144     int readTempData () {
00145         /** 温度の読み出し
00146          *  @return int型の変数に代入してください、温度を返します
00147          */
00148         uint8_t rawData[2];  // x/y/z gyro register data stored here
00149         readBytes(TEMP_OUT_H, 2, &rawData[0]);  // Read the two raw data registers sequentially into data array
00150         return (int)(((int8_t)rawData[0]) << 8 | rawData[1]) ;  // Turn the MSB and LSB into a 16-bit value
00151     }
00152 
00153 
00154 
00155 // Configure the motion detection control for low power accelerometer mode
00156     void LowPowerAccelOnly() {
00157 
00158 // The sensor has a high-pass filter necessary to invoke to allow the sensor motion detection algorithms work properly
00159 // Motion detection occurs on free-fall (acceleration below a threshold for some time for all axes), motion (acceleration
00160 // above a threshold for some time on at least one axis), and zero-motion toggle (acceleration on each axis less than a
00161 // threshold for some time sets this flag, motion above the threshold turns it off). The high-pass filter takes gravity out
00162 // consideration for these threshold evaluations; otherwise, the flags would be set all the time!
00163 
00164         uint8_t c = readByte(PWR_MGMT_1);
00165         writeByte(PWR_MGMT_1, c & ~0x30); // Clear sleep and cycle bits [5:6]
00166         writeByte(PWR_MGMT_1, c |  0x30); // Set sleep and cycle bits [5:6] to zero to make sure accelerometer is running
00167 
00168         c = readByte(PWR_MGMT_2);
00169         writeByte(PWR_MGMT_2, c & ~0x38); // Clear standby XA, YA, and ZA bits [3:5]
00170         writeByte(PWR_MGMT_2, c |  0x00); // Set XA, YA, and ZA bits [3:5] to zero to make sure accelerometer is running
00171 
00172         c = readByte(ACCEL_CONFIG);
00173         writeByte(ACCEL_CONFIG, c & ~0x07); // Clear high-pass filter bits [2:0]
00174 // 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
00175         writeByte(ACCEL_CONFIG,  c | 0x00);  // Set ACCEL_HPF to 0; reset mode disbaling high-pass filter
00176 
00177         c = readByte(CONFIG);
00178         writeByte(CONFIG, c & ~0x07); // Clear low-pass filter bits [2:0]
00179         writeByte(CONFIG, c |  0x00);  // Set DLPD_CFG to 0; 260 Hz bandwidth, 1 kHz rate
00180 
00181         c = readByte(INT_ENABLE);
00182         writeByte(INT_ENABLE, c & ~0xFF);  // Clear all interrupts
00183         writeByte(INT_ENABLE, 0x40);  // Enable motion threshold (bits 5) interrupt only
00184 
00185 // Motion detection interrupt requires the absolute value of any axis to lie above the detection threshold
00186 // for at least the counter duration
00187         writeByte(MOT_THR, 0x80); // Set motion detection to 0.256 g; LSB = 2 mg
00188         writeByte(MOT_DUR, 0x01); // Set motion detect duration to 1  ms; LSB is 1 ms @ 1 kHz rate
00189 
00190         wait(0.1);  // Add delay for accumulation of samples
00191 
00192         c = readByte(ACCEL_CONFIG);
00193         writeByte(ACCEL_CONFIG, c & ~0x07); // Clear high-pass filter bits [2:0]
00194         writeByte(ACCEL_CONFIG, c |  0x07);  // Set ACCEL_HPF to 7; hold the initial accleration value as a referance
00195 
00196         c = readByte(PWR_MGMT_2);
00197         writeByte(PWR_MGMT_2, c & ~0xC7); // Clear standby XA, YA, and ZA bits [3:5] and LP_WAKE_CTRL bits [6:7]
00198         writeByte(PWR_MGMT_2, c |  0x47); // Set wakeup frequency to 5 Hz, and disable XG, YG, and ZG gyros (bits [0:2])
00199 
00200         c = readByte(PWR_MGMT_1);
00201         writeByte(PWR_MGMT_1, c & ~0x20); // Clear sleep and cycle bit 5
00202         writeByte(PWR_MGMT_1, c |  0x20); // Set cycle bit 5 to begin low power accelerometer motion interrupts
00203 
00204     }
00205 
00206 
00207     void resetMPU6050() {
00208         // reset device
00209         writeByte(PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
00210         wait(0.1);
00211     }
00212 
00213 
00214     void initMPU6050() {
00215 // Initialize MPU6050 device
00216 // wake up device
00217         writeByte(PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors
00218         wait(0.1); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt
00219 
00220 // get stable time source
00221         writeByte(PWR_MGMT_1, 0x01);  // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
00222 
00223 // Configure Gyro and Accelerometer
00224 // Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively;
00225 // DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both
00226 // Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate
00227         writeByte(CONFIG, 0x03);
00228 
00229 // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV)
00230         writeByte(SMPLRT_DIV, 0x04);  // Use a 200 Hz rate; the same rate set in CONFIG above
00231 
00232 // Set gyroscope full scale range
00233 // Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3
00234         uint8_t c =  readByte(GYRO_CONFIG);
00235         writeByte(GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
00236         writeByte(GYRO_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
00237         writeByte(GYRO_CONFIG, c | _Gscale << 3); // Set full scale range for the gyro
00238 
00239 // Set accelerometer configuration
00240         c =  readByte(ACCEL_CONFIG);
00241         writeByte(ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
00242         writeByte(ACCEL_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
00243         writeByte(ACCEL_CONFIG, c | _Ascale << 3); // Set full scale range for the accelerometer
00244 
00245         // Configure Interrupts and Bypass Enable
00246         // Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips
00247         // can join the I2C bus and all can be controlled by the Arduino as master
00248         writeByte(INT_PIN_CFG, 0x22);
00249         writeByte(INT_ENABLE, 0x01);  // Enable data ready (bit 0) interrupt
00250     }
00251 
00252 // Function which accumulates gyro and accelerometer data after device initialization. It calculates the average
00253 // of the at-rest readings and then loads the resulting offsets into accelerometer and gyro bias registers.
00254     void calibrateMPU6050(float * dest1, float * dest2) {
00255         uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data
00256         uint16_t ii, packet_count, fifo_count;
00257         int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
00258 
00259 // reset device, reset all registers, clear gyro and accelerometer bias registers
00260         writeByte(PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
00261         wait(0.1);
00262 
00263 // get stable time source
00264 // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
00265         writeByte(PWR_MGMT_1, 0x01);
00266         writeByte(PWR_MGMT_2, 0x00);
00267         wait(0.2);
00268 
00269 // Configure device for bias calculation
00270         writeByte(INT_ENABLE, 0x00);   // Disable all interrupts
00271         writeByte(FIFO_EN, 0x00);      // Disable FIFO
00272         writeByte(PWR_MGMT_1, 0x00);   // Turn on internal clock source
00273         writeByte(I2C_MST_CTRL, 0x00); // Disable I2C master
00274         writeByte(USER_CTRL, 0x00);    // Disable FIFO and I2C master modes
00275         writeByte(USER_CTRL, 0x0C);    // Reset FIFO and DMP
00276         wait(0.015);
00277 
00278 // Configure MPU6050 gyro and accelerometer for bias calculation
00279         writeByte(CONFIG, 0x01);      // Set low-pass filter to 188 Hz
00280         writeByte(SMPLRT_DIV, 0x00);  // Set sample rate to 1 kHz
00281         writeByte(GYRO_CONFIG, 0x00);  // Set gyro full-scale to 250 degrees per second, maximum sensitivity
00282         writeByte(ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity
00283 
00284         uint16_t  gyrosensitivity  = 131;   // = 131 LSB/degrees/sec
00285         uint16_t  accelsensitivity = 16384;  // = 16384 LSB/g
00286 
00287 // Configure FIFO to capture accelerometer and gyro data for bias calculation
00288         writeByte(USER_CTRL, 0x40);   // Enable FIFO
00289         writeByte(FIFO_EN, 0x78);     // Enable gyro and accelerometer sensors for FIFO  (max size 1024 bytes in MPU-6050)
00290         wait(0.08); // accumulate 80 samples in 80 milliseconds = 960 bytes
00291 
00292 // At end of sample accumulation, turn off FIFO sensor read
00293         writeByte(FIFO_EN, 0x00);        // Disable gyro and accelerometer sensors for FIFO
00294         readBytes(FIFO_COUNTH, 2, &data[0]); // read FIFO sample count
00295         fifo_count = ((uint16_t)data[0] << 8) | data[1];
00296         packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging
00297 
00298         for (ii = 0; ii < packet_count; ii++) {
00299             int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0};
00300             readBytes(FIFO_R_W, 12, &data[0]); // read data for averaging
00301             accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1]  ) ;  // Form signed 16-bit integer for each sample in FIFO
00302             accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3]  ) ;
00303             accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5]  ) ;
00304             gyro_temp[0]  = (int16_t) (((int16_t)data[6] << 8) | data[7]  ) ;
00305             gyro_temp[1]  = (int16_t) (((int16_t)data[8] << 8) | data[9]  ) ;
00306             gyro_temp[2]  = (int16_t) (((int16_t)data[10] << 8) | data[11]) ;
00307 
00308             accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases
00309             accel_bias[1] += (int32_t) accel_temp[1];
00310             accel_bias[2] += (int32_t) accel_temp[2];
00311             gyro_bias[0]  += (int32_t) gyro_temp[0];
00312             gyro_bias[1]  += (int32_t) gyro_temp[1];
00313             gyro_bias[2]  += (int32_t) gyro_temp[2];
00314 
00315         }
00316         accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases
00317         accel_bias[1] /= (int32_t) packet_count;
00318         accel_bias[2] /= (int32_t) packet_count;
00319         gyro_bias[0]  /= (int32_t) packet_count;
00320         gyro_bias[1]  /= (int32_t) packet_count;
00321         gyro_bias[2]  /= (int32_t) packet_count;
00322 
00323         if(accel_bias[2] > 0L) {
00324             accel_bias[2] -= (int32_t) accelsensitivity;   // Remove gravity from the z-axis accelerometer bias calculation
00325         } else {
00326             accel_bias[2] += (int32_t) accelsensitivity;
00327         }
00328 
00329 // Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup
00330         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
00331         data[1] = (-gyro_bias[0]/4)       & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
00332         data[2] = (-gyro_bias[1]/4  >> 8) & 0xFF;
00333         data[3] = (-gyro_bias[1]/4)       & 0xFF;
00334         data[4] = (-gyro_bias[2]/4  >> 8) & 0xFF;
00335         data[5] = (-gyro_bias[2]/4)       & 0xFF;
00336 
00337 // Push gyro biases to hardware registers
00338         writeByte(XG_OFFS_USRH, data[0]);
00339         writeByte(XG_OFFS_USRL, data[1]);
00340         writeByte(YG_OFFS_USRH, data[2]);
00341         writeByte(YG_OFFS_USRL, data[3]);
00342         writeByte(ZG_OFFS_USRH, data[4]);
00343         writeByte(ZG_OFFS_USRL, data[5]);
00344 
00345         dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction
00346         dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity;
00347         dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity;
00348 
00349 // Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain
00350 // factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold
00351 // non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature
00352 // compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that
00353 // the accelerometer biases calculated above must be divided by 8.
00354 
00355         int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases
00356         readBytes(XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values
00357         accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1];
00358         readBytes(YA_OFFSET_H, 2, &data[0]);
00359         accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1];
00360         readBytes(ZA_OFFSET_H, 2, &data[0]);
00361         accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1];
00362 
00363         uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers
00364         uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis
00365 
00366         for(ii = 0; ii < 3; ii++) {
00367             if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit
00368         }
00369 
00370         // Construct total accelerometer bias, including calculated average accelerometer bias from above
00371         accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale)
00372         accel_bias_reg[1] -= (accel_bias[1]/8);
00373         accel_bias_reg[2] -= (accel_bias[2]/8);
00374 
00375         data[0] = (accel_bias_reg[0] >> 8) & 0xFF;
00376         data[1] = (accel_bias_reg[0])      & 0xFF;
00377         data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers
00378         data[2] = (accel_bias_reg[1] >> 8) & 0xFF;
00379         data[3] = (accel_bias_reg[1])      & 0xFF;
00380         data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers
00381         data[4] = (accel_bias_reg[2] >> 8) & 0xFF;
00382         data[5] = (accel_bias_reg[2])      & 0xFF;
00383         data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers
00384 
00385         // Push accelerometer biases to hardware registers
00386 //  writeByte(XA_OFFSET_H, data[0]);
00387 //  writeByte(XA_OFFSET_L_TC, data[1]);
00388 //  writeByte(YA_OFFSET_H, data[2]);
00389 //  writeByte(YA_OFFSET_L_TC, data[3]);
00390 //  writeByte(ZA_OFFSET_H, data[4]);
00391 //  writeByte(ZA_OFFSET_L_TC, data[5]);
00392 
00393 // Output scaled accelerometer biases for manual subtraction in the main program
00394         dest2[0] = (float)accel_bias[0]/(float)accelsensitivity;
00395         dest2[1] = (float)accel_bias[1]/(float)accelsensitivity;
00396         dest2[2] = (float)accel_bias[2]/(float)accelsensitivity;
00397     }
00398 
00399 
00400 // Accelerometer and gyroscope self test; check calibration wrt factory settings
00401     void MPU6050SelfTest(float * destination) { // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass
00402         uint8_t rawData[4] = {0, 0, 0, 0};
00403         uint8_t selfTest[6];
00404         float factoryTrim[6];
00405 
00406         // Configure the accelerometer for self-test
00407         writeByte(ACCEL_CONFIG, 0xF0); // Enable self test on all three axes and set accelerometer range to +/- 8 g
00408         writeByte(GYRO_CONFIG,  0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
00409         wait(0.25);  // Delay a while to let the device execute the self-test
00410         rawData[0] = readByte(SELF_TEST_X); // X-axis self-test results
00411         rawData[1] = readByte(SELF_TEST_Y); // Y-axis self-test results
00412         rawData[2] = readByte(SELF_TEST_Z); // Z-axis self-test results
00413         rawData[3] = readByte(SELF_TEST_A); // Mixed-axis self-test results
00414         // Extract the acceleration test results first
00415         selfTest[0] = (rawData[0] >> 3) | (rawData[3] & 0x30) >> 4 ; // XA_TEST result is a five-bit unsigned integer
00416         selfTest[1] = (rawData[1] >> 3) | (rawData[3] & 0x0C) >> 4 ; // YA_TEST result is a five-bit unsigned integer
00417         selfTest[2] = (rawData[2] >> 3) | (rawData[3] & 0x03) >> 4 ; // ZA_TEST result is a five-bit unsigned integer
00418         // Extract the gyration test results first
00419         selfTest[3] = rawData[0]  & 0x1F ; // XG_TEST result is a five-bit unsigned integer
00420         selfTest[4] = rawData[1]  & 0x1F ; // YG_TEST result is a five-bit unsigned integer
00421         selfTest[5] = rawData[2]  & 0x1F ; // ZG_TEST result is a five-bit unsigned integer
00422         // Process results to allow final comparison with factory set values
00423         factoryTrim[0] = (4096.0f*0.34f)*(pow( (0.92f/0.34f) , ((selfTest[0] - 1.0f)/30.0f))); // FT[Xa] factory trim calculation
00424         factoryTrim[1] = (4096.0f*0.34f)*(pow( (0.92f/0.34f) , ((selfTest[1] - 1.0f)/30.0f))); // FT[Ya] factory trim calculation
00425         factoryTrim[2] = (4096.0f*0.34f)*(pow( (0.92f/0.34f) , ((selfTest[2] - 1.0f)/30.0f))); // FT[Za] factory trim calculation
00426         factoryTrim[3] =  ( 25.0f*131.0f)*(pow( 1.046f , (selfTest[3] - 1.0f) ));             // FT[Xg] factory trim calculation
00427         factoryTrim[4] =  (-25.0f*131.0f)*(pow( 1.046f , (selfTest[4] - 1.0f) ));             // FT[Yg] factory trim calculation
00428         factoryTrim[5] =  ( 25.0f*131.0f)*(pow( 1.046f , (selfTest[5] - 1.0f) ));             // FT[Zg] factory trim calculation
00429 
00430 //  Output self-test results and factory trim calculation if desired
00431 //  Serial.println(selfTest[0]); Serial.println(selfTest[1]); Serial.println(selfTest[2]);
00432 //  Serial.println(selfTest[3]); Serial.println(selfTest[4]); Serial.println(selfTest[5]);
00433 //  Serial.println(factoryTrim[0]); Serial.println(factoryTrim[1]); Serial.println(factoryTrim[2]);
00434 //  Serial.println(factoryTrim[3]); Serial.println(factoryTrim[4]); Serial.println(factoryTrim[5]);
00435 
00436 // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response
00437 // To get to percent, must multiply by 100 and subtract result from 100
00438         for (int i = 0; i < 6; i++) {
00439             destination[i] = 100.0f + 100.0f*(selfTest[i] - factoryTrim[i])/factoryTrim[i]; // Report percent differences
00440         }
00441 
00442     }
00443 
00444 
00445 // Implementation of Sebastian Madgwick's "...efficient orientation filter for... inertial/magnetic sensor arrays"
00446 // (see http://www.x-io.co.uk/category/open-source/ for examples and more details)
00447 // which fuses acceleration and rotation rate to produce a quaternion-based estimate of relative
00448 // device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc.
00449 // The performance of the orientation filter is at least as good as conventional Kalman-based filtering algorithms
00450 // but is much less computationally intensive---it can be performed on a 3.3 V Pro Mini operating at 8 MHz!
00451     void MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz) {
00452         float q1 = _q[0], q2 = _q[1], q3 = _q[2], q4 = _q[3];         // short name local variable for readability
00453         float norm;                                               // vector norm
00454         float f1, f2, f3;                                         // objective funcyion elements
00455         float J_11or24, J_12or23, J_13or22, J_14or21, J_32, J_33; // objective function Jacobian elements
00456         float qDot1, qDot2, qDot3, qDot4;
00457         float hatDot1, hatDot2, hatDot3, hatDot4;
00458         float gerrx, gerry, gerrz, gbiasx, gbiasy, gbiasz;  // gyro bias error
00459 
00460         // Auxiliary variables to avoid repeated arithmetic
00461         float _halfq1 = 0.5f * q1;
00462         float _halfq2 = 0.5f * q2;
00463         float _halfq3 = 0.5f * q3;
00464         float _halfq4 = 0.5f * q4;
00465         float _2q1 = 2.0f * q1;
00466         float _2q2 = 2.0f * q2;
00467         float _2q3 = 2.0f * q3;
00468         float _2q4 = 2.0f * q4;
00469 //            float _2q1q3 = 2.0f * q1 * q3;
00470 //            float _2q3q4 = 2.0f * q3 * q4;
00471 
00472         // Normalise accelerometer measurement
00473         norm = sqrt(ax * ax + ay * ay + az * az);
00474         if (norm == 0.0f) return; // handle NaN
00475         norm = 1.0f/norm;
00476         ax *= norm;
00477         ay *= norm;
00478         az *= norm;
00479 
00480         // Compute the objective function and Jacobian
00481         f1 = _2q2 * q4 - _2q1 * q3 - ax;
00482         f2 = _2q1 * q2 + _2q3 * q4 - ay;
00483         f3 = 1.0f - _2q2 * q2 - _2q3 * q3 - az;
00484         J_11or24 = _2q3;
00485         J_12or23 = _2q4;
00486         J_13or22 = _2q1;
00487         J_14or21 = _2q2;
00488         J_32 = 2.0f * J_14or21;
00489         J_33 = 2.0f * J_11or24;
00490 
00491         // Compute the gradient (matrix multiplication)
00492         hatDot1 = J_14or21 * f2 - J_11or24 * f1;
00493         hatDot2 = J_12or23 * f1 + J_13or22 * f2 - J_32 * f3;
00494         hatDot3 = J_12or23 * f2 - J_33 *f3 - J_13or22 * f1;
00495         hatDot4 = J_14or21 * f1 + J_11or24 * f2;
00496 
00497         // Normalize the gradient
00498         norm = sqrt(hatDot1 * hatDot1 + hatDot2 * hatDot2 + hatDot3 * hatDot3 + hatDot4 * hatDot4);
00499         hatDot1 /= norm;
00500         hatDot2 /= norm;
00501         hatDot3 /= norm;
00502         hatDot4 /= norm;
00503 
00504         // Compute estimated gyroscope biases
00505         gerrx = _2q1 * hatDot2 - _2q2 * hatDot1 - _2q3 * hatDot4 + _2q4 * hatDot3;
00506         gerry = _2q1 * hatDot3 + _2q2 * hatDot4 - _2q3 * hatDot1 - _2q4 * hatDot2;
00507         gerrz = _2q1 * hatDot4 - _2q2 * hatDot3 + _2q3 * hatDot2 - _2q4 * hatDot1;
00508 
00509         // Compute and remove gyroscope biases
00510         gbiasx += gerrx * deltat * zeta;
00511         gbiasy += gerry * deltat * zeta;
00512         gbiasz += gerrz * deltat * zeta;
00513 //           gx -= gbiasx;
00514 //           gy -= gbiasy;
00515 //           gz -= gbiasz;
00516 
00517         // Compute the quaternion derivative
00518         qDot1 = -_halfq2 * gx - _halfq3 * gy - _halfq4 * gz;
00519         qDot2 =  _halfq1 * gx + _halfq3 * gz - _halfq4 * gy;
00520         qDot3 =  _halfq1 * gy - _halfq2 * gz + _halfq4 * gx;
00521         qDot4 =  _halfq1 * gz + _halfq2 * gy - _halfq3 * gx;
00522 
00523         // Compute then integrate estimated quaternion derivative
00524         q1 += (qDot1 -(beta * hatDot1)) * deltat;
00525         q2 += (qDot2 -(beta * hatDot2)) * deltat;
00526         q3 += (qDot3 -(beta * hatDot3)) * deltat;
00527         q4 += (qDot4 -(beta * hatDot4)) * deltat;
00528 
00529         // Normalize the quaternion
00530         norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);    // normalise quaternion
00531         norm = 1.0f/norm;
00532         _q[0] = q1 * norm;
00533         _q[1] = q2 * norm;
00534         _q[2] = q3 * norm;
00535         _q[3] = q4 * norm;
00536 
00537     }
00538     
00539 private:
00540 // Define registers per MPU6050, Register Map and Descriptions, Rev 4.2, 08/19/2013 6 DOF Motion sensor fusion device
00541 // Invensense Inc., www.invensense.com
00542 // See also MPU-6050 Register Map and Descriptions, Revision 4.0, RM-MPU-6050A-00, 9/12/2012 for registers not listed in
00543 // above document; the MPU6050 and MPU 9150 are virtually identical but the latter has an on-board magnetic sensor
00544     enum register_adr{
00545         XGOFFS_TC           = 0x00, // Bit 7 PWR_MODE, bits 6:1 XG_OFFS_TC, bit 0 OTP_BNK_VLD
00546         YGOFFS_TC           = 0x01,
00547         ZGOFFS_TC           = 0x02,
00548         X_FINE_GAIN         = 0x03, // [7:0] fine gain
00549         Y_FINE_GAIN         = 0x04,
00550         Z_FINE_GAIN         = 0x05,
00551         XA_OFFSET_H         = 0x06, // User-defined trim values for accelerometer
00552         XA_OFFSET_L_TC      = 0x07,
00553         YA_OFFSET_H         = 0x08,
00554         YA_OFFSET_L_TC      = 0x09,
00555         ZA_OFFSET_H         = 0x0A,
00556         ZA_OFFSET_L_TC      = 0x0B,
00557         SELF_TEST_X         = 0x0D,
00558         SELF_TEST_Y         = 0x0E,
00559         SELF_TEST_Z         = 0x0F,
00560         SELF_TEST_A         = 0x10,
00561         XG_OFFS_USRH        = 0x13, // User-defined trim values for gyroscope; supported in MPU-6050?
00562         XG_OFFS_USRL        = 0x14,
00563         YG_OFFS_USRH        = 0x15,
00564         YG_OFFS_USRL        = 0x16,
00565         ZG_OFFS_USRH        = 0x17,
00566         ZG_OFFS_USRL        = 0x18,
00567         SMPLRT_DIV          = 0x19,
00568         CONFIG              = 0x1A,
00569         GYRO_CONFIG         = 0x1B,
00570         ACCEL_CONFIG        = 0x1C,
00571         FF_THR              = 0x1D, // Free-fall
00572         FF_DUR              = 0x1E, // Free-fall
00573         MOT_THR             = 0x1F, // Motion detection threshold bits [7:0]
00574         MOT_DUR             = 0x20, // Duration counter threshold for motion interrupt generation, 1 kHz rate, LSB = 1 ms
00575         ZMOT_THR            = 0x21, // Zero-motion detection threshold bits [7:0]
00576         ZRMOT_DUR           = 0x22, // Duration counter threshold for zero motion interrupt generation, 16 Hz rate, LSB = 64 ms
00577         FIFO_EN             = 0x23,
00578         I2C_MST_CTRL        = 0x24,
00579         I2C_SLV0_ADDR       = 0x25,
00580         I2C_SLV0_REG        = 0x26,
00581         I2C_SLV0_CTRL       = 0x27,
00582         I2C_SLV1_ADDR       = 0x28,
00583         I2C_SLV1_REG        = 0x29,
00584         I2C_SLV1_CTRL       = 0x2A,
00585         I2C_SLV2_ADDR       = 0x2B,
00586         I2C_SLV2_REG        = 0x2C,
00587         I2C_SLV2_CTRL       = 0x2D,
00588         I2C_SLV3_ADDR       = 0x2E,
00589         I2C_SLV3_REG        = 0x2F,
00590         I2C_SLV3_CTRL       = 0x30,
00591         I2C_SLV4_ADDR       = 0x31,
00592         I2C_SLV4_REG        = 0x32,
00593         I2C_SLV4_DO         = 0x33,
00594         I2C_SLV4_CTRL       = 0x34,
00595         I2C_SLV4_DI         = 0x35,
00596         I2C_MST_STATUS      = 0x36,
00597         INT_PIN_CFG         = 0x37,
00598         INT_ENABLE          = 0x38,
00599         DMP_INT_STATUS      = 0x39, // Check DMP interrupt
00600         INT_STATUS          = 0x3A,
00601         ACCEL_XOUT_H        = 0x3B,
00602         ACCEL_XOUT_L        = 0x3C,
00603         ACCEL_YOUT_H        = 0x3D,
00604         ACCEL_YOUT_L        = 0x3E,
00605         ACCEL_ZOUT_H        = 0x3F,
00606         ACCEL_ZOUT_L        = 0x40,
00607         TEMP_OUT_H          = 0x41,
00608         TEMP_OUT_L          = 0x42,
00609         GYRO_XOUT_H         = 0x43,
00610         GYRO_XOUT_L         = 0x44,
00611         GYRO_YOUT_H         = 0x45,
00612         GYRO_YOUT_L         = 0x46,
00613         GYRO_ZOUT_H         = 0x47,
00614         GYRO_ZOUT_L         = 0x48,
00615         EXT_SENS_DATA_00    = 0x49,
00616         EXT_SENS_DATA_01    = 0x4A,
00617         EXT_SENS_DATA_02    = 0x4B,
00618         EXT_SENS_DATA_03    = 0x4C,
00619         EXT_SENS_DATA_04    = 0x4D,
00620         EXT_SENS_DATA_05    = 0x4E,
00621         EXT_SENS_DATA_06    = 0x4F,
00622         EXT_SENS_DATA_07    = 0x50,
00623         EXT_SENS_DATA_08    = 0x51,
00624         EXT_SENS_DATA_09    = 0x52,
00625         EXT_SENS_DATA_10    = 0x53,
00626         EXT_SENS_DATA_11    = 0x54,
00627         EXT_SENS_DATA_12    = 0x55,
00628         EXT_SENS_DATA_13    = 0x56,
00629         EXT_SENS_DATA_14    = 0x57,
00630         EXT_SENS_DATA_15    = 0x58,
00631         EXT_SENS_DATA_16    = 0x59,
00632         EXT_SENS_DATA_17    = 0x5A,
00633         EXT_SENS_DATA_18    = 0x5B,
00634         EXT_SENS_DATA_19    = 0x5C,
00635         EXT_SENS_DATA_20    = 0x5D,
00636         EXT_SENS_DATA_21    = 0x5E,
00637         EXT_SENS_DATA_22    = 0x5F,
00638         EXT_SENS_DATA_23    = 0x60,
00639         MOT_DETECT_STATUS   = 0x61,
00640         I2C_SLV0_DO         = 0x63,
00641         I2C_SLV1_DO         = 0x64,
00642         I2C_SLV2_DO         = 0x65,
00643         I2C_SLV3_DO         = 0x66,
00644         I2C_MST_DELAY_CTRL  = 0x67,
00645         SIGNAL_PATH_RESET   = 0x68,
00646         MOT_DETECT_CTRL     = 0x69,
00647         USER_CTRL           = 0x6A, // Bit 7 enable DMP, bit 3 reset DMP
00648         PWR_MGMT_1          = 0x6B, // Device defaults to the SLEEP mode
00649         PWR_MGMT_2          = 0x6C,
00650         DMP_BANK            = 0x6D, // Activates a specific bank in the DMP
00651         DMP_RW_PNT          = 0x6E, // Set read/write pointer to a specific start address in specified DMP bank
00652         DMP_REG             = 0x6F, // Register in DMP from which to read or to which to write
00653         DMP_REG_1           = 0x70,
00654         DMP_REG_2           = 0x71,
00655         FIFO_COUNTH         = 0x72,
00656         FIFO_COUNTL         = 0x73,
00657         FIFO_R_W            = 0x74,
00658         WHO_AM_I_MPU6050    = 0x75, // Should return 0x68
00659     };
00660     
00661     int _Gscale;
00662     int _Ascale;
00663 
00664     float _q[4]; // vector to hold quaternion
00665     float beta;
00666     float zeta;
00667     float deltat;    // integration interval for both filter schemes
00668 
00669     //I2C
00670     I2C     *i2c_p;
00671     I2C     &i2c;
00672     char    adr;
00673 
00674     void writeByte(uint8_t address, uint8_t data) {
00675         char data_write[2];
00676         data_write[0] = address;
00677         data_write[1] = data;
00678         i2c.write(adr, data_write, 2, 0);
00679     }
00680 
00681     char readByte(uint8_t address) {
00682         char data[1]; // `data` will store the register data
00683         char data_write[1];
00684         data_write[0] = address;
00685         i2c.write(adr, data_write, 1, 1); // no stop
00686         i2c.read(adr, data, 1, 0);
00687         return data[0];
00688     }
00689 
00690     void readBytes(uint8_t address, uint8_t count, uint8_t * dest) {
00691         char data[14];
00692         char data_write[1];
00693         data_write[0] = address;
00694         i2c.write(adr, data_write, 1, 1); // no stop
00695         i2c.read(adr, data, count, 0);
00696         for(int ii = 0; ii < count; ii++) {
00697             dest[ii] = data[ii];
00698         }
00699     }
00700 
00701 };
00702 #endif