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I'm trying to get GPS coordinates using TinyGPS. But it keeps printing ********* for the data fields. Any idea on how to get this working?. Here is what the serial monitor looks like. enter image description here

Here is my code

#include <SoftwareSerial.h>

#include <TinyGPS.h>

/* This sample code demonstrates the normal use of a TinyGPS 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).
*/

TinyGPS gps;
SoftwareSerial ss(1, 0);

static void smartdelay(unsigned long ms);
static void print_float(float val, float invalid, int len, int prec);
static void print_int(unsigned long val, unsigned long invalid, int len);
static void print_date(TinyGPS &gps);
static void print_str(const char *str, int len);

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

  Serial.print("Testing TinyGPS library v. "); Serial.println(TinyGPS::library_version());
  Serial.println("by Mikal Hart");
  Serial.println();
  Serial.println("Sats HDOP Latitude  Longitude  Fix  Date       Time     Date Alt    Course Speed Card  Distance Course Card  Chars Sentences Checksum");
  Serial.println("          (deg)     (deg)      Age                      Age  (m)    --- from GPS ----  ---- to London  ----  RX    RX        Fail");
  Serial.println("-------------------------------------------------------------------------------------------------------------------------------------");

  ss.begin(4800);
}

void loop()
{
  float flat, flon;
  unsigned long age, date, time, chars = 0;
  unsigned short sentences = 0, failed = 0;
  static const double LONDON_LAT = 51.508131, LONDON_LON = -0.128002;

  print_int(gps.satellites(), TinyGPS::GPS_INVALID_SATELLITES, 5);
  print_int(gps.hdop(), TinyGPS::GPS_INVALID_HDOP, 5);
  gps.f_get_position(&flat, &flon, &age);
  print_float(flat, TinyGPS::GPS_INVALID_F_ANGLE, 10, 6);
  print_float(flon, TinyGPS::GPS_INVALID_F_ANGLE, 11, 6);
  print_int(age, TinyGPS::GPS_INVALID_AGE, 5);
  print_date(gps);
  print_float(gps.f_altitude(), TinyGPS::GPS_INVALID_F_ALTITUDE, 7, 2);
  print_float(gps.f_course(), TinyGPS::GPS_INVALID_F_ANGLE, 7, 2);
  print_float(gps.f_speed_kmph(), TinyGPS::GPS_INVALID_F_SPEED, 6, 2);
  print_str(gps.f_course() == TinyGPS::GPS_INVALID_F_ANGLE ? "*** " : TinyGPS::cardinal(gps.f_course()), 6);
  print_int(flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0xFFFFFFFF : (unsigned long)TinyGPS::distance_between(flat, flon, LONDON_LAT, LONDON_LON) / 1000, 0xFFFFFFFF, 9);
  print_float(flat == TinyGPS::GPS_INVALID_F_ANGLE ? TinyGPS::GPS_INVALID_F_ANGLE : TinyGPS::course_to(flat, flon, LONDON_LAT, LONDON_LON), TinyGPS::GPS_INVALID_F_ANGLE, 7, 2);
  print_str(flat == TinyGPS::GPS_INVALID_F_ANGLE ? "*** " : TinyGPS::cardinal(TinyGPS::course_to(flat, flon, LONDON_LAT, LONDON_LON)), 6);

  gps.stats(&chars, &sentences, &failed);
  print_int(chars, 0xFFFFFFFF, 6);
  print_int(sentences, 0xFFFFFFFF, 10);
  print_int(failed, 0xFFFFFFFF, 9);
  Serial.println();

  smartdelay(1000);
}

static void smartdelay(unsigned long ms)
{
  unsigned long start = millis();
  do 
  {
    while (ss.available())
      gps.encode(ss.read());
  } while (millis() - start < ms);
}

static void print_float(float val, float invalid, int len, int prec)
{
  if (val == invalid)
  {
    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 print_int(unsigned long val, unsigned long invalid, int len)
{
  char sz[32];
  if (val == invalid)
    strcpy(sz, "*******");
  else
    sprintf(sz, "%ld", val);
  sz[len] = 0;
  for (int i=strlen(sz); i<len; ++i)
    sz[i] = ' ';
  if (len > 0) 
    sz[len-1] = ' ';
  Serial.print(sz);
  smartdelay(0);
}

static void print_date(TinyGPS &gps)
{
  int year;
  byte month, day, hour, minute, second, hundredths;
  unsigned long age;
  gps.crack_datetime(&year, &month, &day, &hour, &minute, &second, &hundredths, &age);
  if (age == TinyGPS::GPS_INVALID_AGE)
    Serial.print("********** ******** ");
  else
  {
    char sz[32];
    sprintf(sz, "%02d/%02d/%02d %02d:%02d:%02d ",
        month, day, year, hour, minute, second);
    Serial.print(sz);
  }
  print_int(age, TinyGPS::GPS_INVALID_AGE, 5);
  smartdelay(0);
}

static void print_str(const char *str, int len)
{
  int slen = strlen(str);
  for (int i=0; i<len; ++i)
    Serial.print(i<slen ? str[i] : ' ');
  smartdelay(0);
}
  • Looks like you have no signal or it hasn't locked on to the satellites yet. It can take a long time. How long have you waited? Is your antenna indoors? – Majenko Nov 10 '18 at 18:03
  • why don't you simply print the raw serial data that is coming from the GPS module ...... use the above sketch only after the GPS module starts to send valid data – jsotola Nov 10 '18 at 20:29
1
#include <SoftwareSerial.h>
#include <TinyGPS++.h>
#include <SPI.h>

float lattitude,longitude; // create variable for latitude and longitude object 
SoftwareSerial gpsSerial(8,9);//rx,tx
TinyGPSPlus gps;// create gps object

void setup(){
    Serial.begin(9600); // connect serial
    gpsSerial.begin(9600); // connect gps sensor
    delay(1000);
}

void loop(){

  while(1)
  {
   while (gpsSerial.available() > 0)
   { gps.encode(gpsSerial.read()); }

      if (gps.location.isUpdated())
      {
       lattitude=gps.location.lat();
       longitude=gps.location.lng();
       break;
      }

 }
   Serial.print("LATTITUDE="); Serial.println(lattitude,6);
   Serial.print("LONGITUDE="); Serial.println(longitude,6);
   delay(1000);
}

I managed to get it working using the following library TinyGPS++.h

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From the description: 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). */ But you are using Pin0 and Pin 1, as shown in your code: SoftwareSerial ss(1, 0); given that pin0 and pin one are hard Tx and Rx may create problems.

to check if the GPS is receiving anything use the BareMinimum sketch: void setup() { // put your setup code here, to run once: } void loop() { // put your main code here, to run repeatedly: }

//Remember that Tx connects to Tx and Rx to Rx

that will show the NMEA string in the serial monitor.
(you can see a video about it, search for:"GPS Module with Arduino- Ublox NEO-6M"

Note: in TinyGPS the Rx connects to Tx and Tx connects to Rx...

In case you use Softwareserial.h with Arduino Mega you may have issues as not all pins can Rx (receive)... please check: https://www.arduino.cc/en/Reference/SoftwareSerial

for NEO-6M the seed should be 9600baud, not 4800 as shown in the sketch, please check page 11 on:

https://www.u-blox.com/sites/default/files/products/documents/NEO-6_DataSheet_%28GPS.G6-HW-09005%29.pdf

Also change Serial.begin(115200); to 9600 so they are in sync.

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