Jean Philippe Glesser / GPS_JSON

A basic library for the Adafruit Ultimate GPS module. (MTK3339) http://www.adafruit.com/products/746

Fork of GPS by Sam Clarke

GPS.cpp@0:697a7215cc10, 2012-10-06 (annotated)

Committer:
SamClarke
Date:
Sat Oct 06 22:41:59 2012 +0000
Revision:
0:697a7215cc10
Child:
1:0a034c2dbea6
Basic version

Who changed what in which revision?

UserRevisionLine numberNew contents of line
SamClarke 0:697a7215cc10 1 #include "GPS.h"
SamClarke 0:697a7215cc10 2
SamClarke 0:697a7215cc10 3 GPS::GPS(PinName tx, PinName rx) : _UltimateGps(tx, rx)
SamClarke 0:697a7215cc10 4 {
SamClarke 0:697a7215cc10 5 _UltimateGps.baud(9600);
SamClarke 0:697a7215cc10 6 }
SamClarke 0:697a7215cc10 7
SamClarke 0:697a7215cc10 8 int GPS::parseData()
SamClarke 0:697a7215cc10 9 {
SamClarke 0:697a7215cc10 10
SamClarke 0:697a7215cc10 11 while(1) {
SamClarke 0:697a7215cc10 12 getData();
SamClarke 0:697a7215cc10 13 if(sscanf(NEMA, "GPGGA, %*f, %*f, %*c, %*f, %*c, %d, %d, %*f, %f", &fixtype, &satellites, &altitude) >=1);
SamClarke 0:697a7215cc10 14 if(sscanf(NEMA, "GPRMC, %f, %c, %f, %c, %f, %c, %f, %f, %d", &time, &validity, &latitude, &ns, &longitude, &ew, &speed, &heading, &date) >=1) {
SamClarke 0:697a7215cc10 15 if(fixtype == '0') {
SamClarke 0:697a7215cc10 16 return 0;
SamClarke 0:697a7215cc10 17 }
SamClarke 0:697a7215cc10 18 if(fixtype == '1') {
SamClarke 0:697a7215cc10 19 fixname = "Positive";
SamClarke 0:697a7215cc10 20 }
SamClarke 0:697a7215cc10 21 if(fixtype == '2') {
SamClarke 0:697a7215cc10 22 fixname = "Differential";
SamClarke 0:697a7215cc10 23 }
SamClarke 0:697a7215cc10 24 if(ns =='S') {
SamClarke 0:697a7215cc10 25 latitude *= -1.0;
SamClarke 0:697a7215cc10 26 }
SamClarke 0:697a7215cc10 27 if(ew =='W') {
SamClarke 0:697a7215cc10 28 longitude *= -1.0;
SamClarke 0:697a7215cc10 29 }
SamClarke 0:697a7215cc10 30 float degrees = trunc(latitude / 100.0f);
SamClarke 0:697a7215cc10 31 float minutes = latitude - (degrees * 100.0f);
SamClarke 0:697a7215cc10 32 latitude = degrees + minutes / 60.0f;
SamClarke 0:697a7215cc10 33 degrees = trunc(longitude / 100.0f);
SamClarke 0:697a7215cc10 34 minutes = longitude - (degrees * 100.0f);
SamClarke 0:697a7215cc10 35 longitude = degrees + minutes / 60.0f;
SamClarke 0:697a7215cc10 36 return 1;
SamClarke 0:697a7215cc10 37 }
SamClarke 0:697a7215cc10 38 }
SamClarke 0:697a7215cc10 39 }
SamClarke 0:697a7215cc10 40
SamClarke 0:697a7215cc10 41
SamClarke 0:697a7215cc10 42 float GPS::trunc(float v)
SamClarke 0:697a7215cc10 43 {
SamClarke 0:697a7215cc10 44 if(v < 0.0) {
SamClarke 0:697a7215cc10 45 v*= -1.0;
SamClarke 0:697a7215cc10 46 v = floor(v);
SamClarke 0:697a7215cc10 47 v*=-1.0;
SamClarke 0:697a7215cc10 48 } else {
SamClarke 0:697a7215cc10 49 v = floor(v);
SamClarke 0:697a7215cc10 50 }
SamClarke 0:697a7215cc10 51 return v;
SamClarke 0:697a7215cc10 52 }
SamClarke 0:697a7215cc10 53
SamClarke 0:697a7215cc10 54 void GPS::getData()
SamClarke 0:697a7215cc10 55 {
SamClarke 0:697a7215cc10 56 while(_UltimateGps.getc() != '$');
SamClarke 0:697a7215cc10 57 for(int i=0; i<256; i++) {
SamClarke 0:697a7215cc10 58 NEMA[i] = _UltimateGps.getc();
SamClarke 0:697a7215cc10 59 if(NEMA[i] == '\r') {
SamClarke 0:697a7215cc10 60 NEMA[i] = 0;
SamClarke 0:697a7215cc10 61 return;
SamClarke 0:697a7215cc10 62 }
SamClarke 0:697a7215cc10 63 }
SamClarke 0:697a7215cc10 64 error("overflowed message limit");
SamClarke 0:697a7215cc10 65 }
SamClarke 0:697a7215cc10 66
SamClarke 0:697a7215cc10 67 void GPS::Init()
SamClarke 0:697a7215cc10 68 {
SamClarke 0:697a7215cc10 69 _UltimateGps.printf("$PMTK220,1000*1F\r\n");
SamClarke 0:697a7215cc10 70 wait(1);
SamClarke 0:697a7215cc10 71 _UltimateGps.printf("$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n");
SamClarke 0:697a7215cc10 72 wait(1);
SamClarke 0:697a7215cc10 73 }