Getting output from GPS

Forum 2005-2010 (read only) Hardware Interfacing
1

I'm new to Aduino and I'm having trouble with a project using a Duemilanove and an LS20031 GPS reciever module from Sparkfun. I've tried looking though the forums and using the GPS tutorial code without any luck. For the most part I've tried variations on the code below just as a test. I either get -1's or y's with an umlaut depending on the changes I make. The strange thing is that when I hold the reset button the GPS data is automatically spit out to the serial monitor window. Any help will be greatly appreciated.

int rx= 0;
int tx= 1;
char in= 0;

void setup()  {
  pinMode( rx, INPUT);
  pinMode( tx, OUTPUT);
  Serial.begin(57600);
}

void loop()  {
  in= Serial.read();    
  Serial.print(in);
}
2

"-1" says you're reading the serial buffer when it is empty, i.e. you're not waiting for "Serial.available".
"loop" runs much faster than 5760 characters per second can keep up with.

It isn't necessary to set the I/O mode of the serial pins.

3

I tried making the following changes to the code, but still no luck. The program doesn't display anything other than what I write to the serial monitor. The debugging LED doesn't change at all as though the GPS isn't sending any data.

char in= 0;

void setup()  {
  Serial.begin(57600);
  pinMode(13, OUTPUT);
}

void loop()  {
  digitalWrite(13, HIGH);
  if (Serial.available()) {
    digitalWrite(13, LOW);
    in= Serial.read();
    Serial.print(in);
    delay(500);
  } 
}
4

You do have the receive pin of the GPS hooked up to the transmit pin of the arduino and vice versa right? I know that when I picked up a GPS module that threw me for a moment...

5

Sigh... That was it. Thanks for the help

6

Woohoo! I got one!

7

The easiest way to read and extract the data from a gps modul is when you use a Arduino library, i.e TinyGPS (TinyGPS | Arduiniana)