示例#1
0
文件: gps.c 项目: ARMAZILA/FlightCode
void GPS_NewData(uint16_t c)
{
	gps.bytes_rx ++;

	if (!GPS_newFrame(c)) return;

	gps.frames_rx ++;

    sensorsSet(SENSOR_GPS);
    xTimerReset(gpsLostTimer, 10);

    gps.update = (gps.update == 1 ? 0 : 1);

	if (flag(FLAG_GPS_FIX) && gps.numSat > 4)
		xSemaphoreGive(gpsSemaphore);
}
示例#2
0
static void GPS_NewData(uint16_t c)                                                 // Called by uart2Init interrupt
{
    static int32_t  LatSpikeTab[5], LonSpikeTab[5];
    static bool     FilterCleared = false;
    int32_t         diff;
    uint8_t         i;

    if (GPS_newFrame(c))
    {
        if(!GPS_FIX)                                                                // Don't fill spikefilter with pure shit
        {
            if(!FilterCleared)
            {
                for (i = 0; i < 5; i++)
                {
                    LatSpikeTab[i] = 0;
                    LonSpikeTab[i] = 0;
                }
                FilterCleared = true;
            }
        }
        else                                                                        // We have a fix.
        {
            FilterCleared = false;
            FiveElementSpikeFilterINT32(IRQGPS_coord[LAT], LatSpikeTab);            // Always feed filter
            FiveElementSpikeFilterINT32(IRQGPS_coord[LON], LonSpikeTab);
            if (LatSpikeTab[2] && LonSpikeTab[2])                                   // Is the Spikefilter valid and not in runup phase?
            {
                if(!GPS_Conf600[LON])                                               // No scaling?
                {
                    IRQGPS_coord[LAT] = LatSpikeTab[2];
                    IRQGPS_coord[LON] = LonSpikeTab[2];
                }
                else                                                                // We have Scaling. Is new GPS val more than 6m away?
                {                                                                   // If so take the spikefiltervalue
                    if(LatSpikeTab[2] > IRQGPS_coord[LAT]) diff = LatSpikeTab[2] - IRQGPS_coord[LAT];
                    else diff = IRQGPS_coord[LAT] - LatSpikeTab[2];
                    if(abs(diff) > GPS_Conf600[LAT]) IRQGPS_coord[LAT] = LatSpikeTab[2];
                    if(LonSpikeTab[2] > IRQGPS_coord[LON]) diff = LonSpikeTab[2] - IRQGPS_coord[LON];
                    else diff = IRQGPS_coord[LON] - LonSpikeTab[2];
                    if(abs(diff) > GPS_Conf600[LON]) IRQGPS_coord[LON] = LonSpikeTab[2];
                }
            }
        }
        TimestampNewGPSdata = millis();                                             // Set timestamp of Data arrival in MS
    }
}
示例#3
0
文件: gps.c 项目: mcu786/baseflight-2
static void GPS_NewData(uint16_t c)
{
    if (GPS_newFrame(c)) {
        if (GPS_update == 1)
            GPS_update = 0;
        else
            GPS_update = 1;
        if (GPS_fix == 1 && GPS_numSat > 3) {
            if (GPS_fix_home == 0) {
                GPS_fix_home = 1;
                GPS_latitude_home = GPS_latitude;
                GPS_longitude_home = GPS_longitude;
            }
            if (GPSModeHold == 1)
                GPS_distance(GPS_latitude_hold, GPS_longitude_hold, GPS_latitude, GPS_longitude, &GPS_distanceToHold, &GPS_directionToHold);
            else
                GPS_distance(GPS_latitude_home, GPS_longitude_home, GPS_latitude, GPS_longitude, &GPS_distanceToHome, &GPS_directionToHome);
        }
    }
}
示例#4
0
文件: gps.c 项目: tlshen/FUSIONSDK
void GPS_NewData(void) {
	static uint32_t nav_loopTimer;
	uint32_t dist;
	int32_t  dir;
	uint8_t axis;
  int16_t speed;
	uint16_t c = GPSBufferAvailable();
	while (c--) {
		if (GPS_newFrame(GPSBufferRead())) {
			if (GPS_Info.GPS_update == 1) 
				GPS_Info.GPS_update = 0;
			else 
				GPS_Info.GPS_update = 1;
			
			if (fgps.GPS_FIX && GPS_Info.GPS_numSat >= 5) {
				if (!checkArm()) {
					fgps.GPS_FIX_HOME = 0;
				}
				if (!fgps.GPS_FIX_HOME && checkArm()) {
					GPS_reset_home_position();
				}
				//Apply moving average filter to GPS data
#if defined(GPS_FILTERING)
				GPS_filter_index = (GPS_filter_index+1) % GPS_FILTER_VECTOR_LENGTH;
				for (axis = 0; axis< 2; axis++) {
					GPS_data[axis] = GPS_Info.GPS_coord[axis]; //latest unfiltered data is in GPS_latitude and GPS_longitude
					GPS_degree[axis] = GPS_data[axis] / 10000000;  // get the degree to assure the sum fits to the int32_t
					// How close we are to a degree line ? its the first three digits from the fractions of degree
					// later we use it to Check if we are close to a degree line, if yes, disable averaging,
					fraction3[axis] = (GPS_data[axis]- GPS_degree[axis]*10000000) / 10000;
					GPS_filter_sum[axis] -= GPS_filter[axis][GPS_filter_index];
					GPS_filter[axis][GPS_filter_index] = GPS_data[axis] - (GPS_degree[axis]*10000000); 
					GPS_filter_sum[axis] += GPS_filter[axis][GPS_filter_index];
					GPS_filtered[axis] = GPS_filter_sum[axis] / GPS_FILTER_VECTOR_LENGTH + (GPS_degree[axis]*10000000);
					if ( nav_mode == NAV_MODE_POSHOLD) {      //we use gps averaging only in poshold mode...
						if ( fraction3[axis]>1 && fraction3[axis]<999 ) 
							GPS_Info.GPS_coord[axis] = GPS_filtered[axis];
					}
				}
#endif
				//Time for calculating x,y speed and navigation pids
				dTnav = (float)(getTickCount() - nav_loopTimer)/ 10000.0f;
				nav_loopTimer = getTickCount();
				// prevent runup from bad GPS
				dTnav = min(dTnav, 1.0f);  
				//calculate distance and bearings for gui and other stuff continously - From home to copter
				GPS_distance_cm_bearing(&GPS_Info.GPS_coord[LAT],&GPS_Info.GPS_coord[LON],&GPS_Info.GPS_home[LAT],&GPS_Info.GPS_home[LON],&dist,&dir);
				GPS_Info.GPS_distanceToHome = dist/100;
				GPS_Info.GPS_directionToHome = dir/100;
				
				if (!fgps.GPS_FIX_HOME) {     //If we don't have home set, do not display anything
					GPS_Info.GPS_distanceToHome = 0;
					GPS_Info.GPS_directionToHome = 0;
				}
        //calculate the current velocity based on gps coordinates continously to get a valid speed at the moment when we start navigating
        GPS_calc_velocity();        
        if (fgps.GPS_HOLD_MODE || fgps.GPS_HOME_MODE){    //ok we are navigating 
          //do gps nav calculations here, these are common for nav and poshold  
          #if defined(GPS_LEAD_FILTER)
          GPS_distance_cm_bearing(&GPS_coord_lead[LAT],&GPS_coord_lead[LON],&GPS_WP[LAT],&GPS_WP[LON],&wp_distance,&target_bearing);
          GPS_calc_location_error(&GPS_WP[LAT],&GPS_WP[LON],&GPS_coord_lead[LAT],&GPS_coord_lead[LON]);
          #else
          GPS_distance_cm_bearing(&GPS_coord[LAT],&GPS_coord[LON],&GPS_WP[LAT],&GPS_WP[LON],&wp_distance,&target_bearing);
          GPS_calc_location_error(&GPS_WP[LAT],&GPS_WP[LON],&GPS_coord[LAT],&GPS_coord[LON]);
          #endif
          switch (nav_mode) {
            case NAV_MODE_POSHOLD: 
              //Desired output is in nav_lat and nav_lon where 1deg inclination is 100 
              GPS_calc_poshold();
              break;
            case NAV_MODE_WP:
              speed = GPS_calc_desired_speed(NAV_SPEED_MAX, NAV_SLOW_NAV);      //slow navigation 
              // use error as the desired rate towards the target
              //Desired output is in nav_lat and nav_lon where 1deg inclination is 100 
              GPS_calc_nav_rate(speed);
              //Tail control
              if (NAV_CONTROLS_HEADING) {
                if (NAV_TAIL_FIRST) {
                  magHold = wrap_18000(nav_bearing-18000)/100;
                } else {
                  magHold = nav_bearing/100;
                }
              }
              // Are we there yet ?(within 2 meters of the destination)
              if ((wp_distance <= GPS_wp_radius) || check_missed_wp()){         //if yes switch to poshold mode
                nav_mode = NAV_MODE_POSHOLD;
                if (NAV_SET_TAKEOFF_HEADING) { magHold = nav_takeoff_bearing; }
              } 
              break;               
          }
        } //end of gps calcs  
      }
    }
  }
}
示例#5
0
void serialCom() {
  uint8_t c,cc,port,state,bytesTXBuff;
  static uint8_t offset[UART_NUMBER];
  static uint8_t dataSize[UART_NUMBER];
  static uint8_t c_state[UART_NUMBER];
  uint32_t timeMax; // limit max time in this function in case of GPS

  timeMax = micros();
  for(port=0;port<UART_NUMBER;port++) {
    CURRENTPORT=port;
#define RX_COND
#if defined(SERIAL_RX) && (UART_NUMBER > 1)
#define RX_COND && (RX_SERIAL_PORT != port)
#endif
    cc = SerialAvailable(port);
    while (cc-- RX_COND) {
      bytesTXBuff = SerialUsedTXBuff(port); // indicates the number of occupied bytes in TX buffer
      if (bytesTXBuff > TX_BUFFER_SIZE - 50 ) return; // ensure there is enough free TX buffer to go further (50 bytes margin)
      c = SerialRead(port);
#ifdef SUPPRESS_ALL_SERIAL_MSP
      evaluateOtherData(c); // no MSP handling, so go directly
#else //SUPPRESS_ALL_SERIAL_MSP
      state = c_state[port];
      // regular data handling to detect and handle MSP and other data
      if (state == IDLE) {
        if (c=='$') state = HEADER_START;
        else evaluateOtherData(c); // evaluate all other incoming serial data
      } 
      else if (state == HEADER_START) {
        state = (c=='M') ? HEADER_M : IDLE;
      } 
      else if (state == HEADER_M) {
        state = (c=='<') ? HEADER_ARROW : IDLE;
      } 
      else if (state == HEADER_ARROW) {
        if (c > INBUF_SIZE) {  // now we are expecting the payload size
          state = IDLE;
          continue;
        }
        dataSize[port] = c;
        checksum[port] = c;
        offset[port] = 0;
        indRX[port] = 0;
        state = HEADER_SIZE;  // the command is to follow
      } 
      else if (state == HEADER_SIZE) {
        cmdMSP[port] = c;
        checksum[port] ^= c;
        state = HEADER_CMD;
      } 
      else if (state == HEADER_CMD) {
        if (offset[port] < dataSize[port]) {
          checksum[port] ^= c;
          inBuf[offset[port]++][port] = c;
        } 
        else {
          if (checksum[port] == c) // compare calculated and transferred checksum
            evaluateCommand(cmdMSP[port]); // we got a valid packet, evaluate it
          state = IDLE;
          cc = 0; // no more than one MSP per port and per cycle
        }
      }
      c_state[port] = state;

      // SERIAL: try to detect a new nav frame based on the current received buffer
#if defined(GPS_SERIAL)
      if (GPS_SERIAL == port) {
        static uint32_t GPS_last_frame_seen; //Last gps frame seen at this time, used to detect stalled gps communication
        if (GPS_newFrame(c)) {
          //We had a valid GPS data frame, so signal task scheduler to switch to compute
          if (GPS_update == 1) GPS_update = 0; 
          else GPS_update = 1; //Blink GPS update
          GPS_last_frame_seen = timeMax;
          GPS_Frame = 1;
        }

        // Check for stalled GPS, if no frames seen for 1.2sec then consider it LOST
        if ((timeMax - GPS_last_frame_seen) > 1200000) {
          //No update since 1200ms clear fix...
          f.GPS_FIX = 0;
          GPS_numSat = 0;
        }
      }
      if (micros()-timeMax>250) return;  // Limit the maximum execution time of serial decoding to avoid time spike
#endif
#endif // SUPPRESS_ALL_SERIAL_MSP
    } // while
  } // for
}
示例#6
0
uint8_t GPS_NewData(void) {
  uint8_t axis;
  #if defined(I2C_GPS)
    static uint8_t _i2c_gps_status;

    //Do not use i2c_writereg, since writing a register does not work if an i2c_stop command is issued at the end
    //Still investigating, however with separated i2c_repstart and i2c_write commands works... and did not caused i2c errors on a long term test.

    GPS_numSat = (_i2c_gps_status & 0xf0) >> 4;
    _i2c_gps_status = i2c_readReg(I2C_GPS_ADDRESS,I2C_GPS_STATUS_00);                 //Get status register 

    uint8_t *varptr;
    #if defined(I2C_GPS_SONAR)
      i2c_rep_start(I2C_GPS_ADDRESS<<1);
      i2c_write(I2C_GPS_SONAR_ALT);         
      i2c_rep_start((I2C_GPS_ADDRESS<<1)|1);

      varptr = (uint8_t *)&sonarAlt;          // altitude (in cm? maybe)
      *varptr++ = i2c_readAck();
      *varptr   = i2c_readNak();
    #endif	
    
    if (_i2c_gps_status & I2C_GPS_STATUS_3DFIX) {                                     //Check is we have a good 3d fix (numsats>5)
      f.GPS_FIX = 1;

      if (_i2c_gps_status & I2C_GPS_STATUS_NEW_DATA) {                                //Check about new data
        GPS_Frame = 1;

        i2c_rep_start(I2C_GPS_ADDRESS<<1);
        i2c_write(I2C_GPS_LOCATION);                //Start read from here 2x2 bytes distance and direction
        i2c_rep_start((I2C_GPS_ADDRESS<<1)|1);

        varptr = (uint8_t *)&GPS_coord[LAT];        // for latitude displaying
        *varptr++ = i2c_readAck();
        *varptr++ = i2c_readAck();
        *varptr++ = i2c_readAck();
        *varptr   = i2c_readAck();

        varptr = (uint8_t *)&GPS_coord[LON];        // for longitude displaying
        *varptr++ = i2c_readAck();
        *varptr++ = i2c_readAck();
        *varptr++ = i2c_readAck();
        *varptr   = i2c_readNak();

        i2c_rep_start(I2C_GPS_ADDRESS<<1);
        i2c_write(I2C_GPS_GROUND_SPEED);          
        i2c_rep_start((I2C_GPS_ADDRESS<<1)|1);

        varptr = (uint8_t *)&GPS_speed;          // speed in cm/s for OSD
        *varptr++ = i2c_readAck();
        *varptr   = i2c_readAck();

        varptr = (uint8_t *)&GPS_altitude;       // altitude in meters for OSD
        *varptr++ = i2c_readAck();
        *varptr   = i2c_readAck();	

        varptr = (uint8_t *)&GPS_ground_course;
        *varptr++ = i2c_readAck();
        *varptr   = i2c_readNak();

      } else {
        return 0; 
      }
    } else {
      f.GPS_FIX = 0;
      return 0;
    }
  #endif

  #if defined(GPS_SERIAL) || defined(GPS_FROM_OSD)
    #if defined(GPS_SERIAL)
      uint8_t c = SerialAvailable(GPS_SERIAL);
      if (c==0) return 0;
      while (c--) {
        if (GPS_newFrame(SerialRead(GPS_SERIAL))) {
    #elif defined(GPS_FROM_OSD)
      {
        if(GPS_update & 2) {  // Once second bit of GPS_update is set, indicate new GPS datas is readed from OSD - all in right format.
          GPS_update &= 1;    // We have: GPS_fix(0-2), GPS_numSat(0-15), GPS_coord[LAT & LON](signed, in 1/10 000 000 degres), GPS_altitude(signed, in meters) and GPS_speed(in cm/s)                     
    #endif
          GPS_Frame = 1;
        }
      }
  #endif
  return 1;
}

uint8_t GPS_Compute(void) {
  if (GPS_Frame == 0) return 0; else GPS_Frame = 0;

  if (GPS_update == 1) GPS_update = 0; else GPS_update = 1;
  if (f.GPS_FIX && GPS_numSat >= 5) {
    #if !defined(DONT_RESET_HOME_AT_ARM)
       if (!f.ARMED) {f.GPS_FIX_HOME = 0;}
    #endif
    if (!f.GPS_FIX_HOME && f.ARMED) {
      GPS_reset_home_position();
    }

    //Apply moving average filter to GPS data
    #if defined(GPS_FILTERING)
      GPS_filter_index = (GPS_filter_index+1) % GPS_FILTER_VECTOR_LENGTH;
      for (uint8_t axis = 0; axis< 2; axis++) {
        GPS_read[axis] = GPS_coord[axis]; //latest unfiltered data is in GPS_latitude and GPS_longitude
        GPS_degree[axis] = GPS_read[axis] / 10000000;  // get the degree to assure the sum fits to the int32_t
    
        // How close we are to a degree line ? its the first three digits from the fractions of degree
        // later we use it to Check if we are close to a degree line, if yes, disable averaging,
        fraction3[axis] = (GPS_read[axis]- GPS_degree[axis]*10000000) / 10000;
    
        GPS_filter_sum[axis] -= GPS_filter[axis][GPS_filter_index];
        GPS_filter[axis][GPS_filter_index] = GPS_read[axis] - (GPS_degree[axis]*10000000); 
        GPS_filter_sum[axis] += GPS_filter[axis][GPS_filter_index];
        GPS_filtered[axis] = GPS_filter_sum[axis] / GPS_FILTER_VECTOR_LENGTH + (GPS_degree[axis]*10000000);
        if ( nav_mode == NAV_MODE_POSHOLD) {      //we use gps averaging only in poshold mode...
          if ( fraction3[axis]>1 && fraction3[axis]<999 ) GPS_coord[axis] = GPS_filtered[axis];
        }
      }
    #endif

    //dTnav calculation
    //Time for calculating x,y speed and navigation pids
    static uint32_t nav_loopTimer;
    dTnav = (float)(millis() - nav_loopTimer)/ 1000.0;
    nav_loopTimer = millis();
    // prevent runup from bad GPS
    dTnav = min(dTnav, 1.0);  

    //calculate distance and bearings for gui and other stuff continously - From home to copter
    uint32_t dist;
    int32_t  dir;
    GPS_distance_cm_bearing(&GPS_coord[LAT],&GPS_coord[LON],&GPS_home[LAT],&GPS_home[LON],&dist,&dir);
    GPS_distanceToHome = dist/100;
    GPS_directionToHome = dir/100;

    if (!f.GPS_FIX_HOME) {     //If we don't have home set, do not display anything
      GPS_distanceToHome = 0;
      GPS_directionToHome = 0;
    }

    //calculate the current velocity based on gps coordinates continously to get a valid speed at the moment when we start navigating
    GPS_calc_velocity();        

    if (f.GPS_HOLD_MODE || f.GPS_HOME_MODE){    //ok we are navigating 
      //do gps nav calculations here, these are common for nav and poshold  
      #if defined(GPS_LEAD_FILTER)
        GPS_distance_cm_bearing(&GPS_coord_lead[LAT],&GPS_coord_lead[LON],&GPS_WP[LAT],&GPS_WP[LON],&wp_distance,&target_bearing);
        GPS_calc_location_error(&GPS_WP[LAT],&GPS_WP[LON],&GPS_coord_lead[LAT],&GPS_coord_lead[LON]);
      #else
        GPS_distance_cm_bearing(&GPS_coord[LAT],&GPS_coord[LON],&GPS_WP[LAT],&GPS_WP[LON],&wp_distance,&target_bearing);
        GPS_calc_location_error(&GPS_WP[LAT],&GPS_WP[LON],&GPS_coord[LAT],&GPS_coord[LON]);
      #endif
      switch (nav_mode) {
        case NAV_MODE_POSHOLD: 
          //Desired output is in nav_lat and nav_lon where 1deg inclination is 100 
          GPS_calc_poshold();
          break;
        case NAV_MODE_WP:
          int16_t speed = GPS_calc_desired_speed(NAV_SPEED_MAX, NAV_SLOW_NAV);      //slow navigation 
          // use error as the desired rate towards the target
          //Desired output is in nav_lat and nav_lon where 1deg inclination is 100 
          GPS_calc_nav_rate(speed);

          //Tail control
          if (NAV_CONTROLS_HEADING) {
            if (NAV_TAIL_FIRST) {
              magHold = wrap_18000(nav_bearing-18000)/100;
            } else {
              magHold = nav_bearing/100;
            }
          }
          // Are we there yet ?(within 2 meters of the destination)
          if ((wp_distance <= GPS_wp_radius) || check_missed_wp()){         //if yes switch to poshold mode
            nav_mode = NAV_MODE_POSHOLD;
            if (NAV_SET_TAKEOFF_HEADING) { magHold = nav_takeoff_bearing; }
          } 
          break;               
      }
    } //end of gps calcs  
  }
}


void GPS_reset_home_position(void) {
  if (f.GPS_FIX && GPS_numSat >= 5) {
    GPS_home[LAT] = GPS_coord[LAT];
    GPS_home[LON] = GPS_coord[LON];
    GPS_calc_longitude_scaling(GPS_coord[LAT]);  //need an initial value for distance and bearing calc
    nav_takeoff_bearing = att.heading;             //save takeoff heading
    //Set ground altitude
    f.GPS_FIX_HOME = 1;
  }
}

//reset navigation (stop the navigation processor, and clear nav)
void GPS_reset_nav(void) {
  uint8_t i;
  
  for(i=0;i<2;i++) {
    nav_rated[i] = 0;
    nav[i] = 0;
    reset_PID(&posholdPID[i]);
    reset_PID(&poshold_ratePID[i]);
    reset_PID(&navPID[i]);
    nav_mode = NAV_MODE_NONE;
  }
}

//Get the relevant P I D values and set the PID controllers 
void GPS_set_pids(void) {
  posholdPID_PARAM.kP   = (float)conf.pid[PIDPOS].P8/100.0;
  posholdPID_PARAM.kI   = (float)conf.pid[PIDPOS].I8/100.0;
  posholdPID_PARAM.Imax = POSHOLD_RATE_IMAX * 100;
  
  poshold_ratePID_PARAM.kP   = (float)conf.pid[PIDPOSR].P8/10.0;
  poshold_ratePID_PARAM.kI   = (float)conf.pid[PIDPOSR].I8/100.0;
  poshold_ratePID_PARAM.kD   = (float)conf.pid[PIDPOSR].D8/1000.0;
  poshold_ratePID_PARAM.Imax = POSHOLD_RATE_IMAX * 100;
  
  navPID_PARAM.kP   = (float)conf.pid[PIDNAVR].P8/10.0;
  navPID_PARAM.kI   = (float)conf.pid[PIDNAVR].I8/100.0;
  navPID_PARAM.kD   = (float)conf.pid[PIDNAVR].D8/1000.0;
  navPID_PARAM.Imax = POSHOLD_RATE_IMAX * 100;
}
示例#7
0
文件: gps.c 项目: mcu786/baseflight-1
void GPS_NewData(uint16_t c)
{
    uint8_t axis;
    static uint32_t nav_loopTimer;
    uint32_t dist;
    int32_t dir;
    int16_t speed;

    if (GPS_newFrame(c)) {
        if (GPS_update == 1)
            GPS_update = 0;
        else
            GPS_update = 1;
        if (GPS_fix == 1 && GPS_numSat >= 5) {
            if (armed == 0) {
                GPS_fix_home = 0;
            }
            if (GPS_fix_home == 0 && armed) {
                GPS_fix_home = 1;
                GPS_home[LAT] = GPS_coord[LAT];
                GPS_home[LON] = GPS_coord[LON];
                GPS_calc_longitude_scaling(GPS_coord[LAT]); // need an initial value for distance and bearing calc
                nav_takeoff_bearing = heading; // save takeoff heading
            }
            // Apply moving average filter to GPS data
#if defined(GPS_FILTERING)
            GPS_filter_index = ++GPS_filter_index % GPS_FILTER_VECTOR_LENGTH;
            for (axis = 0; axis < 2; axis++) {
                GPS_read[axis] = GPS_coord[axis];       // latest unfiltered data is in GPS_latitude and GPS_longitude
                GPS_degree[axis] = GPS_read[axis] / 10000000;   // get the degree to assure the sum fits to the int32_t

                // How close we are to a degree line ? its the first three digits from the fractions of degree
                // later we use it to Check if we are close to a degree line, if yes, disable averaging,
                fraction3[axis] = (GPS_read[axis] - GPS_degree[axis] * 10000000) / 10000;

                GPS_filter_sum[axis] -= GPS_filter[axis][GPS_filter_index];
                GPS_filter[axis][GPS_filter_index] = GPS_read[axis] - (GPS_degree[axis] * 10000000);
                GPS_filter_sum[axis] += GPS_filter[axis][GPS_filter_index];
                GPS_filtered[axis] = GPS_filter_sum[axis] / GPS_FILTER_VECTOR_LENGTH + (GPS_degree[axis] * 10000000);
                if (nav_mode == NAV_MODE_POSHOLD) {     //we use gps averaging only in poshold mode...
                    if (fraction3[axis] > 1 && fraction3[axis] < 999)
                        GPS_coord[axis] = GPS_filtered[axis];
                }
            }
#endif
            // dTnav calculation
            // Time for calculating x,y speed and navigation pids
            dTnav = (float) (millis() - nav_loopTimer) / 1000.0f;
            nav_loopTimer = millis();
            // prevent runup from bad GPS
            dTnav = min(dTnav, 1.0f);

            // calculate distance and bearings for gui and other stuff continously - From home to copter
            GPS_distance_cm_bearing(&GPS_coord[LAT], &GPS_coord[LON], &GPS_home[LAT], &GPS_home[LON], &dist, &dir);
            GPS_distanceToHome = dist / 100;
            GPS_directionToHome = dir / 100;

            //calculate the current velocity based on gps coordinates continously to get a valid speed at the moment when we start navigating
            GPS_calc_velocity();

            if (GPSModeHold == 1 || GPSModeHome == 1) { // ok we are navigating
                // do gps nav calculations here, these are common for nav and poshold
                GPS_distance_cm_bearing(&GPS_coord[LAT], &GPS_coord[LON], &GPS_WP[LAT], &GPS_WP[LON], &wp_distance, &target_bearing);
                GPS_calc_location_error(&GPS_WP[LAT], &GPS_WP[LON], &GPS_coord[LAT], &GPS_coord[LON]);

                switch (nav_mode) {
                case NAV_MODE_POSHOLD:
                    // Desired output is in nav_lat and nav_lon where 1deg inclination is 100
                    GPS_calc_poshold();
                    break;

                case NAV_MODE_WP:
                    speed = GPS_calc_desired_speed(cfg.nav_speed_max, NAV_SLOW_NAV);    //slow navigation
                    // use error as the desired rate towards the target
                    // Desired output is in nav_lat and nav_lon where 1deg inclination is 100
                    GPS_calc_nav_rate(speed);

                    // Tail control
                    if (cfg.nav_controls_heading) {
                        if (NAV_TAIL_FIRST) {
                            magHold = wrap_18000(nav_bearing - 18000) / 100;
                        } else {
                            magHold = nav_bearing / 100;
                        }
                    }
                    // Are we there yet ?(within x meters of the destination)
                    if ((wp_distance <= cfg.gps_wp_radius) || check_missed_wp()) {      // if yes switch to poshold mode
                        nav_mode = NAV_MODE_POSHOLD;
                        if (NAV_SET_TAKEOFF_HEADING) {
                            magHold = nav_takeoff_bearing;
                        }
                    }
                    break;
                }
            }                   //end of gps calcs
        }
    }
}