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.

Decoders/GPRMCdecoder.hpp@0:0c1aa5906cef, 2014-08-06 (annotated)

Committer:
chris215
Date:
Wed Aug 06 01:37:39 2014 +0000
Revision:
0:0c1aa5906cef
Child:
3:20f8faf2ad18
Renamed library

Who changed what in which revision?

UserRevisionLine numberNew contents of line
chris215 0:0c1aa5906cef 1 #include "mbed.h"
chris215 0:0c1aa5906cef 2 #include "mbedGPSDefs.h"
chris215 0:0c1aa5906cef 3
chris215 0:0c1aa5906cef 4 void DecodeGPRMC(char * tokenStr,GPSInfo& data){
chris215 0:0c1aa5906cef 5 int parameterCount = 0;
chris215 0:0c1aa5906cef 6 char *rest; // to point to the rest of the string after token extraction.
chris215 0:0c1aa5906cef 7 char *token; // to point to the actual token returned.
chris215 0:0c1aa5906cef 8 char *ptr = tokenStr; // make q point to start of hello.
chris215 0:0c1aa5906cef 9 token = strtok_r(ptr, ",",&rest);
chris215 0:0c1aa5906cef 10 while (token != NULL){
chris215 0:0c1aa5906cef 11
chris215 0:0c1aa5906cef 12 if(parameterCount == 1){ //utc fix time
chris215 0:0c1aa5906cef 13 data.time.time[0] = *token;
chris215 0:0c1aa5906cef 14 data.time.time[1] = *(token+1);
chris215 0:0c1aa5906cef 15 data.time.time[2] = *(token+2);
chris215 0:0c1aa5906cef 16 data.time.time[3] = *(token+3);
chris215 0:0c1aa5906cef 17 data.time.time[4] = *(token+4);
chris215 0:0c1aa5906cef 18 data.time.time[5] = *(token+5);
chris215 0:0c1aa5906cef 19 data.time.time[6] = '\0'; //properly finish the string
chris215 0:0c1aa5906cef 20 data.time.hour = (data.time.time[0]-0x30)*10 + (data.time.time[1]-0x30);
chris215 0:0c1aa5906cef 21 data.time.min = (data.time.time[2]-0x30)*10 + (data.time.time[3]-0x30);
chris215 0:0c1aa5906cef 22 data.time.sec = (data.time.time[4]-0x30)*10 + (data.time.time[5]-0x30);
chris215 0:0c1aa5906cef 23 if(*(token+6) == '.')//check is sentence has ms precision, if so parse it
chris215 0:0c1aa5906cef 24 data.time.msec = (*(token+7)-0x30)*100 +(*(token+8)-0x30)*10 + (*(token+9)-0x30);
chris215 0:0c1aa5906cef 25 else
chris215 0:0c1aa5906cef 26 data.time.msec = 0;
chris215 0:0c1aa5906cef 27
chris215 0:0c1aa5906cef 28 }
chris215 0:0c1aa5906cef 29 if(parameterCount == 2){ //GPS fix status
chris215 0:0c1aa5906cef 30 data.GPSStatus = *token;
chris215 0:0c1aa5906cef 31 }
chris215 0:0c1aa5906cef 32 if(parameterCount == 9){ //fix date
chris215 0:0c1aa5906cef 33 data.date.date[0] = *token;
chris215 0:0c1aa5906cef 34 data.date.date[1] = *(token+1);
chris215 0:0c1aa5906cef 35 data.date.date[2] = *(token+2);
chris215 0:0c1aa5906cef 36 data.date.date[3] = *(token+3);
chris215 0:0c1aa5906cef 37 data.date.date[4] = *(token+4);
chris215 0:0c1aa5906cef 38 data.date.date[5] = *(token+5);
chris215 0:0c1aa5906cef 39 data.date.date[6] = '\0'; //properly finish the string
chris215 0:0c1aa5906cef 40 data.date.day = (data.date.date[0]-0x30)*10 + (data.date.date[1]-0x30);
chris215 0:0c1aa5906cef 41 data.date.month = (data.date.date[2]-0x30)*10 + (data.date.date[3]-0x30);;
chris215 0:0c1aa5906cef 42 data.date.year = (data.date.date[4]-0x30)*10 + (data.date.date[5]-0x30);;
chris215 0:0c1aa5906cef 43 }
chris215 0:0c1aa5906cef 44
chris215 0:0c1aa5906cef 45 parameterCount++;
chris215 0:0c1aa5906cef 46 ptr = rest; // rest contains the left over part..assign it to ptr.
chris215 0:0c1aa5906cef 47 token = strtok_r(ptr, ",",&rest);
chris215 0:0c1aa5906cef 48 }
chris215 0:0c1aa5906cef 49 }