The code can't run continual, can only print few words, why?

[shanren]

Hi,
the code attached can only serial monitor few words, why?
Thanks.
Adam

#include <TinyGPS++.h>
#include <SoftwareSerial.h>
#include <Wire.h>
#include <HMC5883L.h>
#include <math.h>
/*
   This sample sketch 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 = 2, TXPin = 3;
static const uint32_t GPSBaud = 9600;
double compass_headingDegrees;
int L1 = 4;
int L2 = 5;
int L3 = 6;
int L4 = 7;


// The TinyGPS++ object
TinyGPSPlus gps;
// the HMC5883L object
HMC5883L compass;

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

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

  Serial.print("File   : "), Serial.println(__FILE__);
  Serial.print("Date   : "), Serial.println(__DATE__);

  Serial.print("setup");
  ss.begin(GPSBaud);
  pinMode(13, OUTPUT);
  pinMode(L1, OUTPUT);
  pinMode(L2, OUTPUT);
  pinMode(L3, OUTPUT);
  pinMode(L4, OUTPUT);
  // Set measurement range
  compass.setRange(HMC5883L_RANGE_1_3GA);

  // Set measurement mode
  compass.setMeasurementMode(HMC5883L_CONTINOUS);

  // Set data rate
  compass.setDataRate(HMC5883L_DATARATE_30HZ);

  // Set number of samples averaged
  compass.setSamples(HMC5883L_SAMPLES_8);

  // Set calibration offset. See HMC5883L_calibration.ino
  compass.setOffset(0, 0);
}

void loop()
{
  // This sketch displays information every time a new sentence is correctly encoded.
  while (ss.available() > 0)
    if (gps.encode(ss.read()))
      gps_track();
  if (millis() > 5000 && gps.charsProcessed() < 10)
  {
    Serial.println(F("No GPS detected: check wiring."));
    while (true);
  }

}

void gps_track()
{
  //*******************compasss data ****************************//
  Vector norm = compass.readNormalize();

  // Calculate heading
  double heading = atan2(norm.YAxis, norm.XAxis);

  // Set declination angle on your location and fix heading
  // You can find your declination on: http://magnetic-declination.com/
  // (+) Positive or (-) for negative
  // For Bytom / Poland declination angle is 4'26E (positive)
  // Formula: (deg + (min / 60.0)) / (180 / M_PI);
  double declinationAngle = (4.0 + (26.0 / 60.0)) / (180 / M_PI);
  heading += declinationAngle;

  // Correct for heading < 0deg and heading > 360deg
  if (heading < 0)
  {
    heading += 2 * PI;
  }

  if (heading > 2 * PI)
  {
    heading -= 2 * PI;
  }

  // Convert to degrees
  compass_headingDegrees = heading * 180 / M_PI;
  if (gps.location.isValid())
  {
    double gps_headingDeg;
    double distance_cal;
    double headingRad;
    double long1 = gps.location.lng() ;
    double lat1 = gps.location.lat();
    double long2 = 87.2345  ;
    double lat2 = 22.1167   ;
    double diflong;
    double diflat;
    double a;
    double c;
    double error;
    lat1 = radians(lat1);
    long1 = radians(long1);
    lat2 = radians(lat2);
    long2 = radians(long2);
    diflong = long1 - long2;
    diflat = lat1 - lat2;
    headingRad = atan2((sin(diflong) * cos(lat2)), ((cos(lat1) * sin(lat2)) - (sin(lat1) * cos(lat2) * cos(diflong))));
    gps_headingDeg = (180 * headingRad) / 3.14159;

    if (gps_headingDeg > 0) {
      gps_headingDeg = gps_headingDeg;
    } else {
      gps_headingDeg = gps_headingDeg + 360;
    }

    error = (gps_headingDeg - compass_headingDegrees);
    if (error < -180) {
      error = error + 360;

    }
    if (error > 180) {
      error = error - 360;


    }

    //*******distance calculation
    a = (sin(diflat / 2) * sin(diflat / 2)) + (cos(lat1) * cos(lat2) * (sin(diflong / 2) * sin(diflong / 2)));
    c = 2 * atan2(sqrt(a), sqrt(1 - a));
    distance_cal = c * 6371000.0; // gives in meters
    //////////****************************error calculation
    Serial.print("gps heading");
    Serial.println(gps_headingDeg);
    Serial.print("magnetic heading");
    Serial.println(compass_headingDegrees);
    Serial.print("error");
    Serial.println(error);
    Serial.print("distance");
    Serial.println(distance_cal);
    bool condition = ((compass_headingDegrees - 10) < gps_headingDeg) && ((compass_headingDegrees + 10) > gps_headingDeg);
    if (condition) {

      fwr();
    } else {
      if (error > 10) {
        rgt();
      }
      if (error < -10) {
        left();
      }
    }
  }
}
void fwr()
{
  digitalWrite(L1, HIGH);
  digitalWrite(L2, LOW);
  digitalWrite(L3, HIGH);
  digitalWrite(L4, LOW);
}
void left() {
  digitalWrite(L1, LOW);
  digitalWrite(L2, HIGH);
  digitalWrite(L3, HIGH);
  digitalWrite(L4, LOW);
}
void rgt() {
  digitalWrite(L1, HIGH);
  digitalWrite(L2, LOW);
  digitalWrite(L3, LOW);
  digitalWrite(L4, HIGH);
}

[Idahowalker]

Try putting a slight delay or a while loop waiting for the serial to had done its startup thing.

like this

Serial.begin(400035678834.7);
while (!Serial) 
 { 
   ; // Wait for serial to connect 
 }

[gcjr]

try commenting out code until it starts to run in order to isolate that cause of the problem

[david_2018]

Put Serial.flush() after each print to wait for the text to be sent.

Does the compass need a .begin or other initialization?

[shanren]

@david_2018

Does the compass need a .begin or other initialization?

Thank you!