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#include "main.h"
int16_t GPS_Nick = 0;
int16_t GPS_Roll = 0;
uint8_t GPS_P_Factor = 0;
uint8_t GPS_D_Factor = 0;
uint8_t flashtimer;
typedef struct
{
int32_t Northing;
int32_t Easting;
uint8_t Status;
} GPS_Pos_t;
// GPS coordinates for hold position
GPS_Pos_t GPSHoldPoint = {0,0, INVALID};
// ---------------------------------------------------------------------------------
void GPS_Main(void)
{
int32_t coscompass, sincompass;
int32_t P_North = 0, D_North = 0, P_East = 0, D_East = 0;
int32_t PD_North = 0, PD_East = 0;
int32_t GPSPosDev_North = 0, GPSPosDev_East = 0;
// poti2 enables the gps feature
if((Poti3 > 70) && (!Notlandung)) // run GPS function only if Poti 2 is larger than 70 (switch on)
{
switch(GPSInfo.status)
{
case INVALID: // invalid gps data
GPS_Nick = 0;
GPS_Roll = 0;
GRN_OFF;
break;
case PROCESSED: // if gps data are already processed
// downcount timeout
if(GPSTimeout) GPSTimeout--;
// if no new data arrived within timeout set current data invalid
// and therefore disable GPS
else
{
GPS_Nick = 0;
GPS_Roll = 0;
GPSInfo.status = INVALID;
}
break;
case VALID: // new valid data from gps device
// if the gps data quality is sufficient
if (GPSInfo.satfix == SATFIX_3D)
{
GRN_ON;
// if sticks are centered and hold position is valid enable position hold control
if ((MaxStickNick < 20) && (MaxStickRoll < 20) && (GPSHoldPoint.Status == VALID))
{
// Calculate deviation from hold position
GPSPosDev_North = GPSInfo.utmnorth - GPSHoldPoint.Northing;
GPSPosDev_East = GPSInfo.utmeast - GPSHoldPoint.Easting;
//Calculate PD-components of the controller (negative sign for compensation)
P_North = -(GPS_P_Factor * GPSPosDev_North)/2048;
D_North = -(GPS_D_Factor * GPSInfo.velnorth)/512;
P_East = -(GPS_P_Factor * GPSPosDev_East)/2048;
D_East = -(GPS_D_Factor * GPSInfo.veleast)/512;
// PD-controller
PD_North = P_North + D_North;
PD_East = P_East + D_East;
// GPS to pitch and roll settings
//A positive pitch angle moves head downwards (flying forward).
//A positive roll angle tilts left side downwards (flying left).
// If compass heading is 0 the head of the copter is in north direction.
// A positive pitch angle will fly to north and a positive roll angle will fly to west.
// In case of a positive north deviation/velocity the
// copter should fly to south (negative pitch).
// In case of a positive east position deviation and a positive east velocity the
// copter should fly to west (positive roll).
// The influence of the GPS_Nick and GPS_Roll variable is contrarily to the stick values
// in the fc.c. Therefore a positive north deviation/velocity should result in a positive
// GPS_Nick and a positive east deviation/velocity should result in a negative GPS_Roll.
// rotation transformation to compass heading to match any copter orientation
coscompass = (int32_t)cos_i(KompassValue);
sincompass = (int32_t)sin_i(KompassValue);
GPS_Roll = (int16_t)((PD_East * coscompass - PD_North * sincompass) / 1024);
GPS_Nick = -1*(int16_t)((PD_East * sincompass + PD_North * coscompass) / 1024);
// limit GPS controls
#define GPS_CTRL_LIMIT 35
if (GPS_Nick > GPS_CTRL_LIMIT) GPS_Nick = GPS_CTRL_LIMIT;
if (GPS_Nick < -GPS_CTRL_LIMIT) GPS_Nick = -GPS_CTRL_LIMIT;
if (GPS_Roll > GPS_CTRL_LIMIT) GPS_Roll = GPS_CTRL_LIMIT;
if (GPS_Roll < -GPS_CTRL_LIMIT) GPS_Roll = -GPS_CTRL_LIMIT;
}
else // MK controlled by user
{
// update hold point to current gps position
GPSHoldPoint.Northing = GPSInfo.utmnorth;
GPSHoldPoint.Easting = GPSInfo.utmeast;
GPSHoldPoint.Status = VALID;
// disable gps control
GPS_Nick = 0;
GPS_Roll = 0;
}
} // eof 3D-FIX
else // no 3D-SATFIX
{ // diable gps control
GPS_Nick = 0;
GPS_Roll = 0;
if (!flashtimer--)
{
GRN_FLASH;
flashtimer=5;
}
}
// set current data as processed to avoid further calculations on the same gps data
GPSInfo.status = PROCESSED;
break;
} // eof GPSInfo.status
}
else GRN_OFF;
return;
}