GPS - distance between two points

Projects General Guidance
1

Hello there,

I'm using TinyGPSPlus code with my GPS (em-506).
My goal is calculating the distance between two points and to set alert (led turn on) before i approaching the destination.
Someone can help with the code or tell me what i need to do?

The code I'm using:

#include <TinyGPS++.h>
#include <SoftwareSerial.h>
/*
This sample code demonstrates the normal use of a TinyGPS++ (TinyGPSPlus) object.
It requires the use of SoftwareSerial, and assumes that you have a
4800-baud serial GPS device hooked up on pins 4(rx) and 3(tx).
*/
static const int RXPin = 4, TXPin = 3;
static const uint32_t GPSBaud = 4800;

// The TinyGPS++ object
TinyGPSPlus gps;

// The serial connection to the GPS device
SoftwareSerial ss(RXPin, TXPin);

void setup()
{
Serial.begin(115200);
ss.begin(GPSBaud);

Serial.println(F("FullExample.ino"));
Serial.println(F("An extensive example of many interesting TinyGPS++ features"));
Serial.print(F("Testing TinyGPS++ library v. ")); Serial.println(TinyGPSPlus::libraryVersion());
Serial.println(F("by Mikal Hart"));
Serial.println();
Serial.println(F("Sats HDOP Latitude Longitude Fix Date Time Date Alt Course Speed Card Distance Course Card Chars Sentences Checksum"));
Serial.println(F(" (deg) (deg) Age Age (m) --- from GPS ---- ---- to London ---- RX RX Fail"));
Serial.println(F("---------------------------------------------------------------------------------------------------------------------------------------"));
}

void loop()
{
static const double LONDON_LAT = 51.508131, LONDON_LON = -0.128002;

printInt(gps.satellites.value(), gps.satellites.isValid(), 5);
printInt(gps.hdop.value(), gps.hdop.isValid(), 5);
printFloat(gps.location.lat(), gps.location.isValid(), 11, 6);
printFloat(gps.location.lng(), gps.location.isValid(), 12, 6);
printInt(gps.location.age(), gps.location.isValid(), 5);
printDateTime(gps.date, gps.time);
printFloat(gps.altitude.meters(), gps.altitude.isValid(), 7, 2);
printFloat(gps.course.deg(), gps.course.isValid(), 7, 2);
printFloat(gps.speed.kmph(), gps.speed.isValid(), 6, 2);
printStr(gps.course.isValid() ? TinyGPSPlus::cardinal(gps.course.value()) : "*** ", 6);

unsigned long distanceKmToLondon =
(unsigned long)TinyGPSPlus::distanceBetween(
gps.location.lat(),
gps.location.lng(),
LONDON_LAT,
LONDON_LON) / 1000;
printInt(distanceKmToLondon, gps.location.isValid(), 9);

double courseToLondon =
TinyGPSPlus::courseTo(
gps.location.lat(),
gps.location.lng(),
LONDON_LAT,
LONDON_LON);

printFloat(courseToLondon, gps.location.isValid(), 7, 2);

const char *cardinalToLondon = TinyGPSPlus::cardinal(courseToLondon);

printStr(gps.location.isValid() ? cardinalToLondon : "*** ", 6);

printInt(gps.charsProcessed(), true, 6);
printInt(gps.sentencesWithFix(), true, 10);
printInt(gps.failedChecksum(), true, 9);
Serial.println();

smartDelay(1000);

if (millis() > 5000 && gps.charsProcessed() < 10)
Serial.println(F("No GPS data received: check wiring"));
}

// This custom version of delay() ensures that the gps object
// is being "fed".
static void smartDelay(unsigned long ms)
{
unsigned long start = millis();
do
{
while (ss.available())
gps.encode(ss.read());
} while (millis() - start < ms);
}

static void printFloat(float val, bool valid, int len, int prec)
{
if (!valid)
{
while (len-- > 1)
Serial.print('*');
Serial.print(' ');
}
else
{
Serial.print(val, prec);
int vi = abs((int)val);
int flen = prec + (val < 0.0 ? 2 : 1); // . and -
flen += vi >= 1000 ? 4 : vi >= 100 ? 3 : vi >= 10 ? 2 : 1;
for (int i=flen; i<len; ++i)
Serial.print(' ');
}
smartDelay(0);
}

static void printInt(unsigned long val, bool valid, int len)
{
char sz[32] = "*****************";
if (valid)
sprintf(sz, "%ld", val);
sz[len] = 0;
for (int i=strlen(sz); i<len; ++i)
sz = ' ';

  • if (len > 0)*

  • sz[len-1] = ' ';*

  • Serial.print(sz);*

  • smartDelay(0);*
    }
    static void printDateTime(TinyGPSDate &d, TinyGPSTime &t)
    {

  • if (!d.isValid())*

  • {*
    _ Serial.print(F("********** "));_

  • }*

  • else*

  • {*

  • char sz[32];*

  • sprintf(sz, "%02d/%02d/%02d ", d.month(), d.day(), d.year());*

  • Serial.print(sz);*

  • }*

  • if (!t.isValid())*

  • {*
    _ Serial.print(F("******** "));_

  • }*

  • else*

  • {*

  • char sz[32];*

  • sprintf(sz, "%02d:%02d:%02d ", t.hour(), t.minute(), t.second());*

  • Serial.print(sz);*

  • }*

  • printInt(d.age(), d.isValid(), 5);*

  • smartDelay(0);*
    }
    static void printStr(const char *str, int len)
    {

  • int slen = strlen(str);*

  • for (int i=0; i<len; ++i)*
    _ Serial.print(i<slen ? str : ' ');_
    * smartDelay(0);*
    }
    Thanks in advance.

2

And now with code tags please.

Have a closer look at the library header for more functions.

3

OK, here's how it works.

Go and read the instructions, then go back and modify your post (use the "More --> Modify" option to the bottom right of the post) to mark up the code as such so we can examine it conveniently and accurately.

Note: Also mark up any data in the same way. This includes error output that you get from the IDE.

Until you reply and demonstrate that you understand these points, it is unlikely that anyone is interested in looking at your code, so I will leave it at that for the present.