GPS Shield returns no response (fastrax UP501)

Projects Networking, Protocols, and Devices
1

Hi guys,

I recently have brought a new up501 GPS shield to use with my Arduino Due.

I mounted the shield on a bread board as to avoid any pin conflict that might come up because of the SPI configuration of the two boards.
I have also hooked up the shield with jumper wires to connect the TX and RX to Arduino Due's pins D14 and D15 which are for Serial3 .
I have the power and ground pins connected via jumper wires as well, but it seems that i cannot retrieve any data.

Here are the test code and results

void setup()
{
  Serial.begin(9600);
 Serial3.begin(9600);
   Serial.println("-------------------------------------------------------------------------------------------------------------------------------------");
}

void loop()
{

  Serial.println("loop");
  pollGPSData();
}

static void pollGPSData()
{
  long start = millis();
  do {
    while (Serial3.available())
    {
      char c = Serial3.read();
      Serial.write (c);
    }  
  } while (millis() -  start < 1000);
  Serial3.flush();[hr]

}

The code result are the following

-------------------------------------------------------------------------------------------------------------------------------------
loop
loop
loop
loop
loop
loop
loop
loop

I believe that the PPS pin has a constant output which i have verified putting a jumper from PPS pin to TX pin. now I'm getting raw data...

-------------------------------------------------------------------------------------------------------------------------------------
loop
loop
loop
loop
loop
loop
loop
loop
$GPGGA,003320.036,,,,,0,0,,,M,,M,,*4F
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GP0M0.05loop
$GPGGA,003321.036,,,,,0,0,,,M,,M,,*4E
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GP0M0.04loop
$GPGGA,003322.036,,,,,0,0,,,M,,M,,*4D
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GP0,3.1
loop

My question is, Why can't I read data without using the PPS pin?

I know that the pins are configured as follows:
pin 1-->TX
pin2 -->RX
pin3 -->GRD
pin4--> main VDD
pin5-->backup VDD (shorted with pin 4)
pin 6-->PPS

Have I missed something?

Thanks in advance.