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@2:72ac4d7044a7, 2016-02-14 (annotated)

Committer:
chris215
Date:
Sun Feb 14 05:55:38 2016 +0000
Revision:
2:72ac4d7044a7
Parent:
1:fade122a76a8
Child:
4:d911d7c4e09d
Modified librairy to increase performance. Reduced interrupt overhead by removing most of the nema parsing.

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