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      1 /*
      2  $License:
      3    Copyright 2011 InvenSense, Inc.
      4 
      5  Licensed under the Apache License, Version 2.0 (the "License");
      6  you may not use this file except in compliance with the License.
      7  You may obtain a copy of the License at
      8 
      9  http://www.apache.org/licenses/LICENSE-2.0
     10 
     11  Unless required by applicable law or agreed to in writing, software
     12  distributed under the License is distributed on an "AS IS" BASIS,
     13  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  See the License for the specific language governing permissions and
     15  limitations under the License.
     16   $
     17  */
     18 
     19 /******************************************************************************
     20  *
     21  * $Id: mlsupervisor.c 5637 2011-06-14 01:13:53Z mcaramello $
     22  *
     23  *****************************************************************************/
     24 
     25 /**
     26  *  @defgroup   ML_SUPERVISOR
     27  *  @brief      Basic sensor fusion supervisor functionalities.
     28  *
     29  *  @{
     30  *      @file   mlsupervisor.c
     31  *      @brief  Basic sensor fusion supervisor functionalities.
     32  */
     33 
     34 #include "ml.h"
     35 #include "mldl.h"
     36 #include "mldl_cfg.h"
     37 #include "mltypes.h"
     38 #include "mlinclude.h"
     39 #include "compass.h"
     40 #include "pressure.h"
     41 #include "dmpKey.h"
     42 #include "dmpDefault.h"
     43 #include "mlstates.h"
     44 #include "mlFIFO.h"
     45 #include "mlFIFOHW.h"
     46 #include "mlMathFunc.h"
     47 #include "mlsupervisor.h"
     48 #include "mlmath.h"
     49 
     50 #include "mlsl.h"
     51 #include "mlos.h"
     52 
     53 #include <log.h>
     54 #undef MPL_LOG_TAG
     55 #define MPL_LOG_TAG "MPL-sup"
     56 
     57 static unsigned long lastCompassTime = 0;
     58 static unsigned long polltime = 0;
     59 static unsigned long coiltime = 0;
     60 static int accCount = 0;
     61 static int compassCalStableCount = 0;
     62 static int compassCalCount = 0;
     63 static int coiltimerstart = 0;
     64 static unsigned long disturbtime = 0;
     65 static int disturbtimerstart = 0;
     66 
     67 static yas_filter_if_s f;
     68 static yas_filter_handle_t handle;
     69 
     70 #define SUPERVISOR_DEBUG 0
     71 
     72 struct inv_supervisor_cb_obj ml_supervisor_cb = { 0 };
     73 
     74 /**
     75  *  @brief  This initializes all variables that should be reset on
     76  */
     77 void inv_init_sensor_fusion_supervisor(void)
     78 {
     79     lastCompassTime = 0;
     80     polltime = 0;
     81     inv_obj.acc_state = SF_STARTUP_SETTLE;
     82     accCount = 0;
     83     compassCalStableCount = 0;
     84     compassCalCount = 0;
     85 
     86     yas_filter_init(&f);
     87     f.init(&handle);
     88 
     89 #if defined CONFIG_MPU_SENSORS_MPU6050A2 || \
     90 	defined CONFIG_MPU_SENSORS_MPU6050B1
     91     if (inv_compass_present()) {
     92         struct mldl_cfg *mldl_cfg = inv_get_dl_config();
     93         if (mldl_cfg->pdata->compass.bus == EXT_SLAVE_BUS_SECONDARY) {
     94             (void)inv_send_external_sensor_data(INV_ELEMENT_1 | INV_ELEMENT_2 | INV_ELEMENT_3, INV_16_BIT);
     95         }
     96     }
     97 #endif
     98 
     99     if (ml_supervisor_cb.supervisor_reset_func != NULL) {
    100         ml_supervisor_cb.supervisor_reset_func();
    101     }
    102 }
    103 
    104 static int MLUpdateCompassCalibration3DOF(int command, long *data,
    105                                           unsigned long deltaTime)
    106 {
    107     INVENSENSE_FUNC_START;
    108     int retValue = INV_SUCCESS;
    109     static float m[10][10] = { {0} };
    110     float mInv[10][10] = { {0} };
    111     float mTmp[10][10] = { {0} };
    112     static float xTransY[4] = { 0 };
    113     float magSqr = 0;
    114     float inpData[3] = { 0 };
    115     int i, j;
    116     int a, b;
    117     float d;
    118 
    119     switch (command) {
    120     case CAL_ADD_DATA:
    121         inpData[0] = (float)data[0];
    122         inpData[1] = (float)data[1];
    123         inpData[2] = (float)data[2];
    124         m[0][0] += (-2 * inpData[0]) * (-2 * inpData[0]);
    125         m[0][1] += (-2 * inpData[0]) * (-2 * inpData[1]);
    126         m[0][2] += (-2 * inpData[0]) * (-2 * inpData[2]);
    127         m[0][3] += (-2 * inpData[0]);
    128         m[1][0] += (-2 * inpData[1]) * (-2 * inpData[0]);
    129         m[1][1] += (-2 * inpData[1]) * (-2 * inpData[1]);
    130         m[1][2] += (-2 * inpData[1]) * (-2 * inpData[2]);
    131         m[1][3] += (-2 * inpData[1]);
    132         m[2][0] += (-2 * inpData[2]) * (-2 * inpData[0]);
    133         m[2][1] += (-2 * inpData[2]) * (-2 * inpData[1]);
    134         m[2][2] += (-2 * inpData[2]) * (-2 * inpData[2]);
    135         m[2][3] += (-2 * inpData[2]);
    136         m[3][0] += (-2 * inpData[0]);
    137         m[3][1] += (-2 * inpData[1]);
    138         m[3][2] += (-2 * inpData[2]);
    139         m[3][3] += 1.0f;
    140         magSqr =
    141             inpData[0] * inpData[0] + inpData[1] * inpData[1] +
    142             inpData[2] * inpData[2];
    143         xTransY[0] += (-2 * inpData[0]) * magSqr;
    144         xTransY[1] += (-2 * inpData[1]) * magSqr;
    145         xTransY[2] += (-2 * inpData[2]) * magSqr;
    146         xTransY[3] += magSqr;
    147         break;
    148     case CAL_RUN:
    149         a = 4;
    150         b = a;
    151         for (i = 0; i < b; i++) {
    152             for (j = 0; j < b; j++) {
    153                 a = b;
    154                 inv_matrix_det_inc(&m[0][0], &mTmp[0][0], &a, i, j);
    155                 mInv[j][i] = SIGNM(i + j) * inv_matrix_det(&mTmp[0][0], &a);
    156             }
    157         }
    158         a = b;
    159         d = inv_matrix_det(&m[0][0], &a);
    160         if (d == 0) {
    161             return INV_ERROR;
    162         }
    163         for (i = 0; i < 3; i++) {
    164             float tmp = 0;
    165             for (j = 0; j < 4; j++) {
    166                 tmp += mInv[j][i] / d * xTransY[j];
    167             }
    168             inv_obj.compass_test_bias[i] =
    169                 -(long)(tmp * inv_obj.compass_sens / 16384.0f);
    170         }
    171         break;
    172     case CAL_RESET:
    173         for (i = 0; i < 4; i++) {
    174             for (j = 0; j < 4; j++) {
    175                 m[i][j] = 0;
    176             }
    177             xTransY[i] = 0;
    178         }
    179     default:
    180         break;
    181     }
    182     return retValue;
    183 }
    184 
    185 /**
    186  * Entry point for Sensor Fusion operations
    187  * @internal
    188  * @param magFB magnetormeter FB
    189  * @param accSF accelerometer SF
    190  */
    191 static inv_error_t MLSensorFusionSupervisor(double *magFB, long *accSF,
    192                                             unsigned long deltaTime)
    193 {
    194     static long prevCompassBias[3] = { 0 };
    195     static long magMax[3] = {
    196         -1073741824L,
    197         -1073741824L,
    198         -1073741824L
    199     };
    200     static long magMin[3] = {
    201         1073741824L,
    202         1073741824L,
    203         1073741824L
    204     };
    205     int gyroMag;
    206     long accMag;
    207     inv_error_t result;
    208     int i;
    209 
    210     if (ml_supervisor_cb.progressive_no_motion_supervisor_func != NULL) {
    211         ml_supervisor_cb.progressive_no_motion_supervisor_func(deltaTime);
    212     }
    213 
    214     gyroMag = inv_get_gyro_sum_of_sqr() >> GYRO_MAG_SQR_SHIFT;
    215     accMag = inv_accel_sum_of_sqr();
    216 
    217     // Scaling below assumes certain scaling.
    218 #if ACC_MAG_SQR_SHIFT != 16
    219 #error
    220 #endif
    221 
    222     if (ml_supervisor_cb.sensor_fusion_advanced_func != NULL) {
    223         result = ml_supervisor_cb.sensor_fusion_advanced_func(magFB, deltaTime);
    224         if (result) {
    225             LOG_RESULT_LOCATION(result);
    226             return result;
    227         }
    228     } else if (inv_params_obj.bias_mode & INV_MAG_BIAS_FROM_MOTION) {
    229         //Most basic compass calibration, used only with lite MPL
    230         if (inv_obj.resetting_compass == 1) {
    231             for (i = 0; i < 3; i++) {
    232                 magMax[i] = -1073741824L;
    233                 magMin[i] = 1073741824L;
    234                 prevCompassBias[i] = 0;
    235             }
    236             compassCalStableCount = 0;
    237             compassCalCount = 0;
    238             inv_obj.resetting_compass = 0;
    239         }
    240         if ((gyroMag > 400) || (inv_get_gyro_present() == 0)) {
    241             if (compassCalStableCount < 1000) {
    242                 for (i = 0; i < 3; i++) {
    243                     if (inv_obj.compass_sensor_data[i] > magMax[i]) {
    244                         magMax[i] = inv_obj.compass_sensor_data[i];
    245                     }
    246                     if (inv_obj.compass_sensor_data[i] < magMin[i]) {
    247                         magMin[i] = inv_obj.compass_sensor_data[i];
    248                     }
    249                 }
    250                 MLUpdateCompassCalibration3DOF(CAL_ADD_DATA,
    251                                                inv_obj.compass_sensor_data,
    252                                                deltaTime);
    253                 compassCalStableCount += deltaTime;
    254                 for (i = 0; i < 3; i++) {
    255                     if (magMax[i] - magMin[i] <
    256                         (long long)40 * 1073741824 / inv_obj.compass_sens) {
    257                         compassCalStableCount = 0;
    258                     }
    259                 }
    260             } else {
    261                 if (compassCalStableCount >= 1000) {
    262                     if (MLUpdateCompassCalibration3DOF
    263                         (CAL_RUN, inv_obj.compass_sensor_data,
    264                          deltaTime) == INV_SUCCESS) {
    265                         inv_obj.got_compass_bias = 1;
    266                         inv_obj.compass_accuracy = 3;
    267                         for(i=0; i<3; i++) {
    268                             inv_obj.compass_bias_error[i] = 35;
    269                         }
    270                         if (inv_obj.compass_state == SF_UNCALIBRATED)
    271                             inv_obj.compass_state = SF_STARTUP_SETTLE;
    272                         inv_set_compass_bias(inv_obj.compass_test_bias);
    273                     }
    274                     compassCalCount = 0;
    275                     compassCalStableCount = 0;
    276                     for (i = 0; i < 3; i++) {
    277                         magMax[i] = -1073741824L;
    278                         magMin[i] = 1073741824L;
    279                         prevCompassBias[i] = 0;
    280                     }
    281                     MLUpdateCompassCalibration3DOF(CAL_RESET,
    282                                                    inv_obj.compass_sensor_data,
    283                                                    deltaTime);
    284                 }
    285             }
    286         }
    287         compassCalCount += deltaTime;
    288         if (compassCalCount > 20000) {
    289             compassCalCount = 0;
    290             compassCalStableCount = 0;
    291             for (i = 0; i < 3; i++) {
    292                 magMax[i] = -1073741824L;
    293                 magMin[i] = 1073741824L;
    294                 prevCompassBias[i] = 0;
    295             }
    296             MLUpdateCompassCalibration3DOF(CAL_RESET,
    297                                            inv_obj.compass_sensor_data,
    298                                            deltaTime);
    299         }
    300     }
    301 
    302     if (inv_obj.acc_state != SF_STARTUP_SETTLE) {
    303         if (((accMag > 260000L) || (accMag < 6000)) || (gyroMag > 2250000L)) {
    304             inv_obj.acc_state = SF_DISTURBANCE; //No accels, fast swing
    305             accCount = 0;
    306         } else {
    307             if ((gyroMag < 400) && (accMag < 200000L) && (accMag > 26214)
    308                 && ((inv_obj.acc_state == SF_DISTURBANCE)
    309                     || (inv_obj.acc_state == SF_SLOW_SETTLE))) {
    310                 accCount += deltaTime;
    311                 if (accCount > 0) {
    312                     inv_obj.acc_state = SF_FAST_SETTLE;
    313                     accCount = 0;
    314                 }
    315             } else {
    316                 if (inv_obj.acc_state == SF_DISTURBANCE) {
    317                     accCount += deltaTime;
    318                     if (accCount > 500) {
    319                         inv_obj.acc_state = SF_SLOW_SETTLE;
    320                         accCount = 0;
    321                     }
    322                 } else if (inv_obj.acc_state == SF_SLOW_SETTLE) {
    323                     accCount += deltaTime;
    324                     if (accCount > 1000) {
    325                         inv_obj.acc_state = SF_NORMAL;
    326                         accCount = 0;
    327                     }
    328                 } else if (inv_obj.acc_state == SF_FAST_SETTLE) {
    329                     accCount += deltaTime;
    330                     if (accCount > 250) {
    331                         inv_obj.acc_state = SF_NORMAL;
    332                         accCount = 0;
    333                     }
    334                 }
    335             }
    336         }
    337     }
    338     if (inv_obj.acc_state == SF_STARTUP_SETTLE) {
    339         accCount += deltaTime;
    340         if (accCount > 50) {
    341             *accSF = 1073741824;    //Startup settling
    342             inv_obj.acc_state = SF_NORMAL;
    343             accCount = 0;
    344         }
    345     } else if ((inv_obj.acc_state == SF_NORMAL)
    346                || (inv_obj.acc_state == SF_SLOW_SETTLE)) {
    347         *accSF = inv_obj.accel_sens * 64;   //Normal
    348     } else if ((inv_obj.acc_state == SF_DISTURBANCE)) {
    349         *accSF = inv_obj.accel_sens * 64;   //Don't use accel (should be 0)
    350     } else if (inv_obj.acc_state == SF_FAST_SETTLE) {
    351         *accSF = inv_obj.accel_sens * 512;  //Amplify accel
    352     }
    353     if (!inv_get_gyro_present()) {
    354         *accSF = inv_obj.accel_sens * 128;
    355     }
    356     return INV_SUCCESS;
    357 }
    358 
    359 /**
    360  *  @brief  Entry point for software sensor fusion operations.
    361  *          Manages hardware interaction, calls sensor fusion supervisor for
    362  *          bias calculation.
    363  *  @return error code. INV_SUCCESS if no error occurred.
    364  */
    365 inv_error_t inv_accel_compass_supervisor(void)
    366 {
    367     inv_error_t result;
    368     int adjustSensorFusion = 0;
    369     long accSF = 1073741824;
    370     static double magFB = 0;
    371     long magSensorData[3];
    372     float fcin[3];
    373     float fcout[3];
    374 
    375 
    376     if (inv_compass_present()) {    /* check for compass data */
    377         int i, j;
    378         long long tmp[3] = { 0 };
    379         long long tmp64 = 0;
    380         unsigned long ctime = inv_get_tick_count();
    381         if (((inv_get_compass_id() == COMPASS_ID_AK8975) &&
    382              ((ctime - polltime) > 20)) ||
    383             (polltime == 0 || ((ctime - polltime) > 20))) { // 50Hz max
    384             if (SUPERVISOR_DEBUG) {
    385                 MPL_LOGV("Fetch compass data from inv_process_fifo_packet\n");
    386                 MPL_LOGV("delta time = %ld\n", ctime - polltime);
    387             }
    388             polltime = ctime;
    389             result = inv_get_compass_data(magSensorData);
    390             /* external slave wants the data even if there is an error */
    391             if (result && !inv_obj.external_slave_callback) {
    392                 if (SUPERVISOR_DEBUG) {
    393                     MPL_LOGW("inv_get_compass_data returned %d\n", result);
    394                 }
    395             } else {
    396                 unsigned long compassTime = inv_get_tick_count();
    397                 unsigned long deltaTime = 1;
    398 
    399                 if (result == INV_SUCCESS) {
    400                     if (lastCompassTime != 0) {
    401                         deltaTime = compassTime - lastCompassTime;
    402                     }
    403                     lastCompassTime = compassTime;
    404                     adjustSensorFusion = 1;
    405                     if (inv_obj.got_init_compass_bias == 0) {
    406                         inv_obj.got_init_compass_bias = 1;
    407                         for (i = 0; i < 3; i++) {
    408                             inv_obj.init_compass_bias[i] = magSensorData[i];
    409                         }
    410                     }
    411                     for (i = 0; i < 3; i++) {
    412                         inv_obj.compass_sensor_data[i] = (long)magSensorData[i];
    413                         inv_obj.compass_sensor_data[i] -=
    414                             inv_obj.init_compass_bias[i];
    415                         tmp[i] = ((long long)inv_obj.compass_sensor_data[i])
    416                             * inv_obj.compass_sens / 16384;
    417                         tmp[i] -= inv_obj.compass_bias[i];
    418                         tmp[i] = (tmp[i] * inv_obj.compass_scale[i]) / 65536L;
    419                     }
    420                     for (i = 0; i < 3; i++) {
    421                         tmp64 = 0;
    422                         for (j = 0; j < 3; j++) {
    423                             tmp64 += (long long) tmp[j] *
    424                                 inv_obj.compass_cal[i * 3 + j];
    425                         }
    426                         inv_obj.compass_calibrated_data[i] =
    427                             (long) (tmp64 / inv_obj.compass_sens);
    428                     }
    429                     //Additions:
    430                     if ((inv_obj.compass_state == 1) &&
    431                             (inv_obj.compass_overunder == 0)) {
    432                         if (disturbtimerstart == 0) {
    433                             disturbtimerstart = 1;
    434                             disturbtime = ctime;
    435                         }
    436                     } else {
    437                         disturbtimerstart = 0;
    438                     }
    439 
    440                     if (inv_obj.compass_overunder) {
    441                         if (coiltimerstart == 0) {
    442                             coiltimerstart = 1;
    443                             coiltime = ctime;
    444                         }
    445                     }
    446                     if (coiltimerstart == 1) {
    447                         if (ctime - coiltime > 3000) {
    448                             inv_obj.flags[INV_COMPASS_OFFSET_VALID] = 0;
    449                             inv_set_compass_offset();
    450                             inv_reset_compass_calibration();
    451                             coiltimerstart = 0;
    452                         }
    453                     }
    454 
    455                     if (disturbtimerstart == 1) {
    456                         if (ctime - disturbtime > 10000) {
    457                             inv_obj.flags[INV_COMPASS_OFFSET_VALID] = 0;
    458                             inv_set_compass_offset();
    459                             inv_reset_compass_calibration();
    460                             MPL_LOGI("Compass reset! inv_reset_compass_calibration \n");
    461                             disturbtimerstart = 0;
    462                         }
    463                     }
    464                 }
    465                 if (inv_obj.external_slave_callback) {
    466                     result = inv_obj.external_slave_callback(&inv_obj);
    467                     if (result) {
    468                         LOG_RESULT_LOCATION(result);
    469                         return result;
    470                     }
    471                 }
    472 
    473 #ifdef APPLY_COMPASS_FILTER
    474                 if (inv_get_compass_id() == COMPASS_ID_YAS530)
    475                 {
    476                     fcin[0] = 1000*((float)inv_obj.compass_calibrated_data[0] /65536.f);
    477                     fcin[1] = 1000*((float)inv_obj.compass_calibrated_data[1] /65536.f);
    478                     fcin[2] = 1000*((float)inv_obj.compass_calibrated_data[2] /65536.f);
    479 
    480                     f.update(&handle, fcin, fcout);
    481 
    482                     inv_obj.compass_calibrated_data[0] = (long)(fcout[0]*65536.f/1000.f);
    483                     inv_obj.compass_calibrated_data[1] = (long)(fcout[1]*65536.f/1000.f);
    484                     inv_obj.compass_calibrated_data[2] = (long)(fcout[2]*65536.f/1000.f);
    485                 }
    486 #endif
    487 
    488                 if (SUPERVISOR_DEBUG) {
    489                     MPL_LOGI("RM : %+10.6f %+10.6f %+10.6f\n",
    490                              (float)inv_obj.compass_calibrated_data[0] /
    491                              65536.f,
    492                              (float)inv_obj.compass_calibrated_data[1] /
    493                              65536.f,
    494                              (float)inv_obj.compass_calibrated_data[2] /
    495                              65536.f);
    496                 }
    497                 magFB = 1.0;
    498                 adjustSensorFusion = 1;
    499                 result = MLSensorFusionSupervisor(&magFB, &accSF, deltaTime);
    500                 if (result) {
    501                     LOG_RESULT_LOCATION(result);
    502                     return result;
    503                 }
    504             }
    505         }
    506     } else {
    507         //No compass, but still modify accel
    508         unsigned long ctime = inv_get_tick_count();
    509         if (polltime == 0 || ((ctime - polltime) > 80)) {   // at the beginning AND every 1/8 second
    510             unsigned long deltaTime = 1;
    511             adjustSensorFusion = 1;
    512             magFB = 0;
    513             if (polltime != 0) {
    514                 deltaTime = ctime - polltime;
    515             }
    516             MLSensorFusionSupervisor(&magFB, &accSF, deltaTime);
    517             polltime = ctime;
    518         }
    519     }
    520     if (adjustSensorFusion == 1) {
    521         unsigned char regs[4];
    522         static int prevAccSF = 1;
    523 
    524         if (accSF != prevAccSF) {
    525             regs[0] = (unsigned char)((accSF >> 24) & 0xff);
    526             regs[1] = (unsigned char)((accSF >> 16) & 0xff);
    527             regs[2] = (unsigned char)((accSF >> 8) & 0xff);
    528             regs[3] = (unsigned char)(accSF & 0xff);
    529             result = inv_set_mpu_memory(KEY_D_0_96, 4, regs);
    530             if (result) {
    531                 LOG_RESULT_LOCATION(result);
    532                 return result;
    533             }
    534             prevAccSF = accSF;
    535         }
    536     }
    537 
    538     if (ml_supervisor_cb.accel_compass_fusion_func != NULL)
    539         ml_supervisor_cb.accel_compass_fusion_func(magFB);
    540 
    541     return INV_SUCCESS;
    542 }
    543 
    544 /**
    545  *  @brief  Entry point for software sensor fusion operations.
    546  *          Manages hardware interaction, calls sensor fusion supervisor for
    547  *          bias calculation.
    548  *  @return INV_SUCCESS or non-zero error code on error.
    549  */
    550 inv_error_t inv_pressure_supervisor(void)
    551 {
    552     long pressureSensorData[1];
    553     static unsigned long pressurePolltime = 0;
    554     if (inv_pressure_present()) {   /* check for pressure data */
    555         unsigned long ctime = inv_get_tick_count();
    556         if ((pressurePolltime == 0 || ((ctime - pressurePolltime) > 80))) { //every 1/8 second
    557             if (SUPERVISOR_DEBUG) {
    558                 MPL_LOGV("Fetch pressure data\n");
    559                 MPL_LOGV("delta time = %ld\n", ctime - pressurePolltime);
    560             }
    561             pressurePolltime = ctime;
    562             if (inv_get_pressure_data(&pressureSensorData[0]) == INV_SUCCESS) {
    563                 inv_obj.pressure = pressureSensorData[0];
    564             }
    565         }
    566     }
    567     return INV_SUCCESS;
    568 }
    569 
    570 /**
    571  *  @brief  Resets the magnetometer calibration algorithm.
    572  *  @return INV_SUCCESS if successful, or non-zero error code otherwise.
    573  */
    574 inv_error_t inv_reset_compass_calibration(void)
    575 {
    576     if (inv_params_obj.bias_mode & INV_MAG_BIAS_FROM_GYRO) {
    577         if (ml_supervisor_cb.reset_advanced_compass_func != NULL)
    578             ml_supervisor_cb.reset_advanced_compass_func();
    579     }
    580     MLUpdateCompassCalibration3DOF(CAL_RESET, inv_obj.compass_sensor_data, 1);
    581 
    582     inv_obj.compass_bias_error[0] = P_INIT;
    583     inv_obj.compass_bias_error[1] = P_INIT;
    584     inv_obj.compass_bias_error[2] = P_INIT;
    585     inv_obj.compass_accuracy = 0;
    586 
    587     inv_obj.got_compass_bias = 0;
    588     inv_obj.got_init_compass_bias = 0;
    589     inv_obj.compass_state = SF_UNCALIBRATED;
    590     inv_obj.resetting_compass = 1;
    591 
    592     return INV_SUCCESS;
    593 }
    594 
    595 /**
    596  *  @}
    597  */
    598