Advice/Help with the GPS EM-506, as there's no signal

Hello everyone,

I would need help with how the Globalsat EM 506 GPS works.

My issue is that I do not receive any data from pin 4 which corresponds to the TX of the GPS.

In fact, I am not receiving any signal from the GPS.

At most, I notice that the red LED of the GPS is dimly lit with 5V (from the Arduino) but when I connect pin 5 of the GPS (GND) and pin 6 of the GPS (Directive) to the ground of the circuit (which is that of the Arduino), the red LED lights up completely.

From then on, I don't know if the GPS is functional but that it's not in a fixed position or quite simply that it is not functional.

I tried to switch the connection of the RX and TX of the GPS but without success.

Do some of you already worked with this GPS?

If yes? What am I missing? And how do you check that the GPS is still functional?

I have attached a photo of my circuit and copy pasted the code at the end of the post.

Thanks to all of you!

Here's the code that's being used :




#include <TinyGPS++.h>
#include <SoftwareSerial.h>

/*
 This example uses software serial and the TinyGPS++ library by Mikal Hart
 Based on TinyGPSPlus/DeviceExample.ino by Mikal Hart
 Modified by acavis
*/

// Choose two Arduino pins to use for software serial
// The GPS Shield uses D2 and D3 by default when in DLINE mode
int RXPin = 2;
int TXPin = 3;

int directive = 7;

// The Skytaq EM-506 GPS module included in the GPS Shield Kit
// uses 4800 baud by default
int GPSBaud = 4800;

// Create a TinyGPS++ object called "gps"
TinyGPSPlus gps;

// Create a software serial port called "gpsSerial"
SoftwareSerial gpsSerial(RXPin, TXPin);

void setup()
{
  // Start the Arduino hardware serial port at 9600 baud
  Serial.begin(9600);

  pinMode(directive, INPUT);

  // Start the software serial port at the GPS's default baud
  gpsSerial.begin(GPSBaud);

  Serial.print(F("Testing TinyGPS++ library v. ")); 
  Serial.println(TinyGPSPlus::libraryVersion());
  Serial.println();
}

void loop()
{
/* 
  int lecture = digitalRead(directive);
  Serial.println("Voici le résultat de la pin directive");
  Serial.println(lecture);
*/  
  
  // This sketch displays information every time a new sentence is correctly encoded.
  while (gpsSerial.available() > 0)
    if (gps.encode(gpsSerial.read()))
      displayInfo();

  // If 5000 milliseconds pass and there are no characters coming in
  // over the software serial port, show a "No GPS detected" error
  if (millis() > 5000 && gps.charsProcessed() < 10)
  {
    Serial.println(F("No GPS detected"));
    while(true);
  }
}

void displayInfo()
{
  Serial.print(F("Location: ")); 
  if (gps.location.isValid())
  {
    Serial.print(gps.location.lat(), 6);
    Serial.print(F(","));
    Serial.print(gps.location.lng(), 6);
  }
  else
  {
    Serial.print(F("INVALID"));
  }

  Serial.print(F("  Date/Time: "));
  if (gps.date.isValid())
  {
    Serial.print(gps.date.month());
    Serial.print(F("/"));
    Serial.print(gps.date.day());
    Serial.print(F("/"));
    Serial.print(gps.date.year());
  }
  else
  {
    Serial.print(F("INVALID"));
  }

  Serial.print(F(" "));
  if (gps.time.isValid())
  {
    if (gps.time.hour() < 10) Serial.print(F("0"));
    Serial.print(gps.time.hour());
    Serial.print(F(":"));
    if (gps.time.minute() < 10) Serial.print(F("0"));
    Serial.print(gps.time.minute());
    Serial.print(F(":"));
    if (gps.time.second() < 10) Serial.print(F("0"));
    Serial.print(gps.time.second());
    Serial.print(F("."));
    if (gps.time.centisecond() < 10) Serial.print(F("0"));
    Serial.print(gps.time.centisecond());
  }
  else
  {
    Serial.print(F("INVALID"));
  }

  Serial.println();
}

Here's the circuit of the GPS EM 506 to the arduino :

The RX pin should not be connected directly to the Arduino pin 2 since its only 3.6V compatible.

Also, try attached an LED in the directive pin (+ side) and see if it blinks once per second.

GPS pin 6 --> (+ LED -) ----> resistor ---> GND

Hi hzrnbgy,

Thanks for your input.

So put a voltage divider for the arduino pin and now it outputs 1.63 V to the GPS Rx pin.
Also, I wired a resistor with a LED to see if the directive pin blink per second and it stays on with a very dimmed light.

The voltages seem fine as I have for the GPS pins :
VIN : 4.83 V
RX : 1.63 V
TX : 33.36 V
Directive : 1.73 V

Still there's no GPS detected