NEO-M8N giving latitude and longitude values of 0

Projects Networking, Protocols, and Devices
1

We're doing a college project where we have to build a self-moving obstacle avoiding robot that shows its coordinates. We're using a NEO-M8N GPS module.

Regarding only the coordinates:
In our output (in the Serial Monitor window) the heading angle is working fine, however the latitude and longitude values are always 0.000000_0.

We can't figure out what's wrong, any help would be seriously appreciated.
Here is our code:

//---------------------MAGNET-------------------------------------
#include <Wire.h>
#define Declination       -0.0375245789
#define hmc5883l_address  0x1E

//---------------------FIM----------------------------------------
#include "Ublox.h"
#define N_FLOATS 3
Ublox M8_Gps;
float gpsArray[N_FLOATS] = {0, 0, 0};

#include <SoftwareSerial.h>
//SoftwareSerial mySerial(RX,TX);
SoftwareSerial mySerial(4, 5);

void setup()
{
  Serial.begin(9600);
  mySerial.begin(9600);
  Wire.begin(12, 14); /* join i2c bus with SDA=D6 and SCL=D5 of NodeMCU */
  hmc5883l_init();
}

//---------------------MAGNET--------------------------------------
void hmc5883l_init() {  /* Magneto initialize function */
  Wire.beginTransmission(hmc5883l_address);
  Wire.write(0x00);
  Wire.write(0x70); //8 samples per measurement, 15Hz data output rate, Normal measurement
  Wire.write(0xA0); //
  Wire.write(0x00); //Continuous measurement mode
  Wire.endTransmission();
  delay(500);
}

int hmc5883l_GetHeading() {
  int16_t x, y, z;
  double Heading;
  Wire.beginTransmission(hmc5883l_address);
  Wire.write(0x03);
  Wire.endTransmission();
  /* Read 16 bit x,y,z value (2's complement form) */
  Wire.requestFrom(hmc5883l_address, 6);
  x = (((int16_t)Wire.read() << 8) | (int16_t)Wire.read());
  z = (((int16_t)Wire.read() << 8) | (int16_t)Wire.read());
  y = (((int16_t)Wire.read() << 8) | (int16_t)Wire.read());

  Heading = atan2((double)y, (double)x) + Declination;
  if (Heading > 2 * PI) /* Due to declination check for >360 degree */
    Heading = Heading - 2 * PI;
  if (Heading < 0)  /* Check for sign */
    Heading = Heading + 2 * PI;
  return (Heading * 180 / PI); /* Convert into angle and return */
}

//---------------------FIM----------------------------------------
void loop()
{
  //---------------------MAGNET-------------------------------------
  Serial.print("Heading Angle : ");
  Serial.println(hmc5883l_GetHeading());
  //delay(2000);
  //---------------------FIM----------------------------------------
  if (!mySerial.available())
    return;

  while (mySerial.available())
  {
    char c = mySerial.read();
    if (M8_Gps.encode(c))
    {
      //gpsArray[0] = M8_Gps.altitude;
      gpsArray[0] = M8_Gps.latitude;
      gpsArray[1] = M8_Gps.longitude;
      gpsArray[2] = M8_Gps.sats_in_use;
    }
  }
  for (byte i = 0; i < 3; i++)
  {
    if (i == 2)
    {
      Serial.print(gpsArray[i], 0); Serial.println("");
    }
    else
    {
      Serial.print(gpsArray[i], 6); Serial.print("_");
    }
  }
  delay(1000);
}
2 
    char c = mySerial.read();
    if (M8_Gps.encode(c))

Here, Ublox instance, is a character from an NMEA sentence. Do something with it. I do NOT want to know what it is, so do NOT tell me.

Ummm, why don't you want to know? Perhaps if you printed c, a clue-by-four would whack you.