christian b / GPS

Mbed library to handle GPS data reception and parsing

Dependents:   GPS_U-blox_NEO-6M_Code

Features

  • All positionning parameters are contained into a global data structure.
  • Automatic nema string parsing and data structure update.
    • GSA,GGA,VTG and RMC
  • Convert latitude and longitude to decimal value.
  • Converts latittude,longitude and altitude to ECEF coordinates.

Planed developement

  • Test library for RTOS use.
  • Complete the nema parsing decoders (couple of parameters are not parsed yet and not present in the data structure).
  • Add conversion tool to get ENU coordinates.

GPS.cpp@5:8a73e34b3978, 2016-02-16 (annotated)

Committer:
chris215
Date:
Tue Feb 16 02:57:35 2016 +0000
Revision:
5:8a73e34b3978
Parent:
4:d911d7c4e09d 
Function renaming. Adding gps update calls.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
chris215 0:0c1aa5906cef 1 #include "GPS.h"
chris215 0:0c1aa5906cef 2 #include "GPSUtils.hpp"
chris215 0:0c1aa5906cef 3
chris215 0:0c1aa5906cef 4 GPS::GPS(PinName tx, PinName rx) : RawSerial(tx, rx)
chris215 0:0c1aa5906cef 5 {
chris215 4:d911d7c4e09d 6 _gpsTimer.start();
chris215 4:d911d7c4e09d 7 _gpsTimer.reset();
chris215 2:72ac4d7044a7 8 RxQueueSize=0;
chris215 2:72ac4d7044a7 9 RxQueueWriteIndex=0;
chris215 2:72ac4d7044a7 10 RxQueueReadIndex=0;
chris215 1:fade122a76a8 11 RawSerial::baud(115200);
chris215 0:0c1aa5906cef 12 attach(this, &GPS::RxIrqHandler);
chris215 0:0c1aa5906cef 13 }
chris215 0:0c1aa5906cef 14
chris215 0:0c1aa5906cef 15 void GPS::SetBaud(int rate){
chris215 0:0c1aa5906cef 16 RawSerial::baud(rate);
chris215 0:0c1aa5906cef 17 }
chris215 0:0c1aa5906cef 18
chris215 0:0c1aa5906cef 19 void GPS::RxIrqHandler(void)
chris215 0:0c1aa5906cef 20 {
chris215 0:0c1aa5906cef 21 char in;
chris215 0:0c1aa5906cef 22 while(RawSerial::readable())
chris215 0:0c1aa5906cef 23 {
chris215 0:0c1aa5906cef 24 in = RawSerial::getc();
chris215 0:0c1aa5906cef 25 if(in == START_CHAR)
chris215 0:0c1aa5906cef 26 {
chris215 0:0c1aa5906cef 27 insertIndex = 0;
chris215 0:0c1aa5906cef 28 RxMessageBuffer.data[(insertIndex++)%RX_BUFFER_SIZE] = in;
chris215 2:72ac4d7044a7 29 RxMessageBuffer.MessageIsNew = 1;
chris215 0:0c1aa5906cef 30 }
chris215 0:0c1aa5906cef 31 else if(in == END_CHAR)
chris215 0:0c1aa5906cef 32 {
chris215 2:72ac4d7044a7 33 RxMessageBuffer.data[(insertIndex++)%RX_BUFFER_SIZE] = 0;
chris215 2:72ac4d7044a7 34 //identify GPS message
chris215 2:72ac4d7044a7 35 int GPSMessageType = IdentifyGPSMessage(RxMessageBuffer);
chris215 2:72ac4d7044a7 36 if(GPSMessageType > 0)
chris215 2:72ac4d7044a7 37 {
chris215 2:72ac4d7044a7 38 if(GPSMessageType == GPS_GPGGAR)
chris215 2:72ac4d7044a7 39 memcpy(&GPSGGAMessage,&RxMessageBuffer,sizeof(message));
chris215 2:72ac4d7044a7 40 if(GPSMessageType == GPS_GPGSAR)
chris215 2:72ac4d7044a7 41 memcpy(&GPSGSAMessage,&RxMessageBuffer,sizeof(message));
chris215 2:72ac4d7044a7 42 if(GPSMessageType == GPS_GPVTGR)
chris215 2:72ac4d7044a7 43 memcpy(&GPSVTGMessage,&RxMessageBuffer,sizeof(message));
chris215 2:72ac4d7044a7 44 if(GPSMessageType == GPS_GPRMCR)
chris215 2:72ac4d7044a7 45 memcpy(&GPSRMCMessage,&RxMessageBuffer,sizeof(message));
chris215 2:72ac4d7044a7 46 }
chris215 0:0c1aa5906cef 47 }
chris215 0:0c1aa5906cef 48 else
chris215 0:0c1aa5906cef 49 RxMessageBuffer.data[(insertIndex++)%RX_BUFFER_SIZE] = in;
chris215 0:0c1aa5906cef 50 }
chris215 0:0c1aa5906cef 51 }
chris215 5:8a73e34b3978 52 void GPS::UpdateGPS(void)
chris215 2:72ac4d7044a7 53 {
chris215 2:72ac4d7044a7 54 if(GPSRMCMessage.MessageIsNew > 0)
chris215 2:72ac4d7044a7 55 {
chris215 2:72ac4d7044a7 56 GPSRMCMessage.MessageIsNew = 0;
chris215 2:72ac4d7044a7 57 DecodeMessage(GPSRMCMessage,info);
chris215 4:d911d7c4e09d 58 _gpsTimer.reset();
chris215 2:72ac4d7044a7 59 }
chris215 2:72ac4d7044a7 60 if(GPSGGAMessage.MessageIsNew > 0)
chris215 2:72ac4d7044a7 61 {
chris215 2:72ac4d7044a7 62 GPSGGAMessage.MessageIsNew = 0;
chris215 2:72ac4d7044a7 63 DecodeMessage(GPSGGAMessage,info);
chris215 4:d911d7c4e09d 64 _gpsTimer.reset();
chris215 2:72ac4d7044a7 65 }
chris215 2:72ac4d7044a7 66 if(GPSVTGMessage.MessageIsNew > 0)
chris215 2:72ac4d7044a7 67 {
chris215 2:72ac4d7044a7 68 GPSVTGMessage.MessageIsNew = 0;
chris215 2:72ac4d7044a7 69 DecodeMessage(GPSVTGMessage,info);
chris215 4:d911d7c4e09d 70 _gpsTimer.reset();
chris215 2:72ac4d7044a7 71 }
chris215 2:72ac4d7044a7 72 if(GPSGSAMessage.MessageIsNew > 0)
chris215 2:72ac4d7044a7 73 {
chris215 2:72ac4d7044a7 74 GPSGSAMessage.MessageIsNew = 0;
chris215 2:72ac4d7044a7 75 DecodeMessage(GPSGSAMessage,info);
chris215 4:d911d7c4e09d 76 _gpsTimer.reset();
chris215 4:d911d7c4e09d 77 }
chris215 4:d911d7c4e09d 78
chris215 4:d911d7c4e09d 79 if(_gpsTimer.read_ms() > 5000)
chris215 4:d911d7c4e09d 80 {
chris215 4:d911d7c4e09d 81 info.fix = 1;
chris215 2:72ac4d7044a7 82 }
chris215 2:72ac4d7044a7 83 }
chris215 0:0c1aa5906cef 84
chris215 0:0c1aa5906cef 85 ECEFPoint GPS::ReadPositionECEF(void)
chris215 0:0c1aa5906cef 86 {
chris215 0:0c1aa5906cef 87 return GeoDesicToECEF(ReadDecGeodLoc());
chris215 0:0c1aa5906cef 88 }
chris215 0:0c1aa5906cef 89 ECEFDistance GPS::DistanceBetweenTwoWP(ECEFPoint p1,ECEFPoint p2)
chris215 0:0c1aa5906cef 90 {
chris215 5:8a73e34b3978 91
chris215 0:0c1aa5906cef 92 return DistanceBetweenTwoECEFPoints(p1,p2);
chris215 0:0c1aa5906cef 93 }
chris215 0:0c1aa5906cef 94
chris215 0:0c1aa5906cef 95 geodPoint GPS::ReadDecGeodLoc(void){
chris215 0:0c1aa5906cef 96 geodPoint newLoc;
chris215 5:8a73e34b3978 97 UpdateGPS();
chris215 0:0c1aa5906cef 98 newLoc.latitude = nmea_to_dec(info.latitude,info.latLoc);
chris215 0:0c1aa5906cef 99 newLoc.longitude = nmea_to_dec(info.longitude,info.lonLoc);
chris215 0:0c1aa5906cef 100 newLoc.altitude = info.GPSAltitude;
chris215 0:0c1aa5906cef 101 return newLoc;
chris215 0:0c1aa5906cef 102 }
chris215 0:0c1aa5906cef 103
chris215 0:0c1aa5906cef 104 geodPoint GPS::ReadRawGeodLoc(void){
chris215 0:0c1aa5906cef 105 geodPoint newLoc;
chris215 5:8a73e34b3978 106 UpdateGPS();
chris215 0:0c1aa5906cef 107 newLoc.latitude = info.latitude;
chris215 0:0c1aa5906cef 108 newLoc.longitude = info.longitude;
chris215 0:0c1aa5906cef 109 newLoc.altitude = info.GPSAltitude;
chris215 0:0c1aa5906cef 110 return newLoc;
chris215 0:0c1aa5906cef 111 }
chris215 0:0c1aa5906cef 112
chris215 0:0c1aa5906cef 113
chris215 0:0c1aa5906cef 114 bool GPS::FixIs3d(void){
chris215 5:8a73e34b3978 115 UpdateGPS();
chris215 0:0c1aa5906cef 116 return (info.fix == 3);
chris215 0:0c1aa5906cef 117 }
chris215 0:0c1aa5906cef 118 bool GPS::FixIs2d(void){
chris215 5:8a73e34b3978 119 UpdateGPS();
chris215 0:0c1aa5906cef 120 return (FixIs3d() || (info.fix == 2));
chris215 0:0c1aa5906cef 121 }
chris215 0:0c1aa5906cef 122 bool GPS::GPSFixValid(void){
chris215 5:8a73e34b3978 123 UpdateGPS();
chris215 0:0c1aa5906cef 124 return (info.GPSStatus == 'A');
chris215 0:0c1aa5906cef 125 }
chris215 0:0c1aa5906cef 126
chris215 0:0c1aa5906cef 127