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@3:20f8faf2ad18, 2016-02-15 (annotated)

Committer:
chris215
Date:
Mon Feb 15 00:42:32 2016 +0000
Revision:
3:20f8faf2ad18
Parent:
0:0c1aa5906cef 
Code refactor. Replace usage of strtok_r() with a custom version to fix parsing issues when the token is empty.

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 3:20f8faf2ad18 3 #include "DecodersUtils.h"
chris215 3:20f8faf2ad18 4
chris215 0:0c1aa5906cef 5
chris215 0:0c1aa5906cef 6 void DecodeGPRMC(char * tokenStr,GPSInfo& data){
chris215 0:0c1aa5906cef 7 int parameterCount = 0;
chris215 0:0c1aa5906cef 8 char *rest; // to point to the rest of the string after token extraction.
chris215 0:0c1aa5906cef 9 char *token; // to point to the actual token returned.
chris215 0:0c1aa5906cef 10 char *ptr = tokenStr; // make q point to start of hello.
chris215 3:20f8faf2ad18 11 //token = strtok_r(ptr, ",",&rest);
chris215 3:20f8faf2ad18 12 token = strtok_single(ptr, ",");
chris215 0:0c1aa5906cef 13 while (token != NULL){
chris215 0:0c1aa5906cef 14
chris215 0:0c1aa5906cef 15 if(parameterCount == 1){ //utc fix time
chris215 0:0c1aa5906cef 16 data.time.time[0] = *token;
chris215 0:0c1aa5906cef 17 data.time.time[1] = *(token+1);
chris215 0:0c1aa5906cef 18 data.time.time[2] = *(token+2);
chris215 0:0c1aa5906cef 19 data.time.time[3] = *(token+3);
chris215 0:0c1aa5906cef 20 data.time.time[4] = *(token+4);
chris215 0:0c1aa5906cef 21 data.time.time[5] = *(token+5);
chris215 0:0c1aa5906cef 22 data.time.time[6] = '\0'; //properly finish the string
chris215 0:0c1aa5906cef 23 data.time.hour = (data.time.time[0]-0x30)*10 + (data.time.time[1]-0x30);
chris215 0:0c1aa5906cef 24 data.time.min = (data.time.time[2]-0x30)*10 + (data.time.time[3]-0x30);
chris215 0:0c1aa5906cef 25 data.time.sec = (data.time.time[4]-0x30)*10 + (data.time.time[5]-0x30);
chris215 0:0c1aa5906cef 26 if(*(token+6) == '.')//check is sentence has ms precision, if so parse it
chris215 0:0c1aa5906cef 27 data.time.msec = (*(token+7)-0x30)*100 +(*(token+8)-0x30)*10 + (*(token+9)-0x30);
chris215 0:0c1aa5906cef 28 else
chris215 0:0c1aa5906cef 29 data.time.msec = 0;
chris215 0:0c1aa5906cef 30
chris215 0:0c1aa5906cef 31 }
chris215 0:0c1aa5906cef 32 if(parameterCount == 2){ //GPS fix status
chris215 0:0c1aa5906cef 33 data.GPSStatus = *token;
chris215 0:0c1aa5906cef 34 }
chris215 0:0c1aa5906cef 35 if(parameterCount == 9){ //fix date
chris215 0:0c1aa5906cef 36 data.date.date[0] = *token;
chris215 0:0c1aa5906cef 37 data.date.date[1] = *(token+1);
chris215 0:0c1aa5906cef 38 data.date.date[2] = *(token+2);
chris215 0:0c1aa5906cef 39 data.date.date[3] = *(token+3);
chris215 0:0c1aa5906cef 40 data.date.date[4] = *(token+4);
chris215 0:0c1aa5906cef 41 data.date.date[5] = *(token+5);
chris215 0:0c1aa5906cef 42 data.date.date[6] = '\0'; //properly finish the string
chris215 0:0c1aa5906cef 43 data.date.day = (data.date.date[0]-0x30)*10 + (data.date.date[1]-0x30);
chris215 0:0c1aa5906cef 44 data.date.month = (data.date.date[2]-0x30)*10 + (data.date.date[3]-0x30);;
chris215 0:0c1aa5906cef 45 data.date.year = (data.date.date[4]-0x30)*10 + (data.date.date[5]-0x30);;
chris215 0:0c1aa5906cef 46 }
chris215 0:0c1aa5906cef 47
chris215 0:0c1aa5906cef 48 parameterCount++;
chris215 0:0c1aa5906cef 49 ptr = rest; // rest contains the left over part..assign it to ptr.
chris215 3:20f8faf2ad18 50 //token = strtok_r(ptr, ",",&rest);
chris215 3:20f8faf2ad18 51 token = strtok_single(NULL, ",");
chris215 0:0c1aa5906cef 52 }
chris215 0:0c1aa5906cef 53 }