GPS Parsing issue

Hi

OK I'm Stuck. 3 days of YouTube, Googling and pulling hair has made me desperate to get answers.

I'm using an Arduino Mega 2560 with an Adafruit GPS Breakout board (New). I'm trying to get the Example GPS_SoftwareSerial_Parsing to work.

I've hooked it up as per the example.

This is the Result in the Serial Monitor:

Adafruit GPS library basic parsing test!

Time: 00:00:00.000
Date: 0/0/200
Fix: 0 quality: 0

Time: 00:00:00.000
Date: 0/0/200
Fix: 0 quality: 0

Time: 00:00:00.000
Date: 0/0/200
Fix: 0 quality: 0

And that will continue forever.

You might say, ok. I'm inside, GPS hasn't got a fix.

Except it has. After about 30 seconds, The LED blinks every 15 seconds saying its got a fix like the datasheet says. I've tried both indoors and outdoors. Both get same results.
If I load a blank code into the IDE and run that, It produces NMEA Sentences all day. After googling and manually parsing the NMEA sentence, I've checked what the Greenwich time was and with the help of Google earth, the GGA NMEA Sentence comes up with correct time, date and my exact location.

Here is the code

// Test code for Adafruit GPS modules using MTK3329/MTK3339 driver
//
// This code shows how to listen to the GPS module in an interrupt
// which allows the program to have more 'freedom' - just parse
// when a new NMEA sentence is available! Then access data when
// desired.
//
// Tested and works great with the Adafruit Ultimate GPS module
// using MTK33x9 chipset
//    ------> http://www.adafruit.com/products/746
// Pick one up today at the Adafruit electronics shop
// and help support open source hardware & software! -ada

#include <Adafruit_GPS.h>
#include <SoftwareSerial.h>

// Connect the GPS Power pin to 5V
// Connect the GPS Ground pin to ground
// Connect the GPS TX (transmit) pin to Digital 8
// Connect the GPS RX (receive) pin to Digital 7

// you can change the pin numbers to match your wiring:
SoftwareSerial mySerial(8, 7);
Adafruit_GPS GPS(&mySerial);

// Set GPSECHO to 'false' to turn off echoing the GPS data to the Serial console
// Set to 'true' if you want to debug and listen to the raw GPS sentences
#define GPSECHO  true

void setup()
{

  // connect at 115200 so we can read the GPS fast enough and echo without dropping chars
  // also spit it out
  Serial.begin(115200);
  delay(5000);
  Serial.println("Adafruit GPS library basic parsing test!");

  // 9600 NMEA is the default baud rate for Adafruit MTK GPS's- some use 4800
  GPS.begin(9600);

  // uncomment this line to turn on RMC (recommended minimum) and GGA (fix data) including altitude
  GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCGGA);
  // uncomment this line to turn on only the "minimum recommended" data
  //GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCONLY);
  // For parsing data, we don't suggest using anything but either RMC only or RMC+GGA since
  // the parser doesn't care about other sentences at this time

  // Set the update rate
  GPS.sendCommand(PMTK_SET_NMEA_UPDATE_1HZ);   // 1 Hz update rate
  // For the parsing code to work nicely and have time to sort thru the data, and
  // print it out we don't suggest using anything higher than 1 Hz

  // Request updates on antenna status, comment out to keep quiet
  GPS.sendCommand(PGCMD_ANTENNA);

  delay(1000);
  // Ask for firmware version
  mySerial.println(PMTK_Q_RELEASE);
}

uint32_t timer = millis();
void loop()                     // run over and over again
{
  char c = GPS.read();
  // if you want to debug, this is a good time to do it!
  if ((c) && (GPSECHO))
    Serial.write(c);

  // if a sentence is received, we can check the checksum, parse it...
  if (GPS.newNMEAreceived()) {
    // a tricky thing here is if we print the NMEA sentence, or data
    // we end up not listening and catching other sentences!
    // so be very wary if using OUTPUT_ALLDATA and trytng to print out data
    //Serial.println(GPS.lastNMEA());   // this also sets the newNMEAreceived() flag to false

    if (!GPS.parse(GPS.lastNMEA()))   // this also sets the newNMEAreceived() flag to false
      return;  // we can fail to parse a sentence in which case we should just wait for another
  }

  // approximately every 2 seconds or so, print out the current stats
  if (millis() - timer > 2000) {
    timer = millis(); // reset the timer

    Serial.print("\nTime: ");
    if (GPS.hour < 10) { Serial.print('0'); }
    Serial.print(GPS.hour, DEC); Serial.print(':');
    if (GPS.minute < 10) { Serial.print('0'); }
    Serial.print(GPS.minute, DEC); Serial.print(':');
    if (GPS.seconds < 10) { Serial.print('0'); }
    Serial.print(GPS.seconds, DEC); Serial.print('.');
    if (GPS.milliseconds < 10) {
      Serial.print("00");
    } else if (GPS.milliseconds > 9 && GPS.milliseconds < 100) {
      Serial.print("0");
    }
    Serial.println(GPS.milliseconds);
    Serial.print("Date: ");
    Serial.print(GPS.day, DEC); Serial.print('/');
    Serial.print(GPS.month, DEC); Serial.print("/20");
    Serial.println(GPS.year, DEC);
    Serial.print("Fix: "); Serial.print((int)GPS.fix);
    Serial.print(" quality: "); Serial.println((int)GPS.fixquality);
    if (GPS.fix) {
      Serial.print("Location: ");
      Serial.print(GPS.latitude, 4); Serial.print(GPS.lat);
      Serial.print(", ");
      Serial.print(GPS.longitude, 4); Serial.println(GPS.lon);

      Serial.print("Speed (knots): "); Serial.println(GPS.speed);
      Serial.print("Angle: "); Serial.println(GPS.angle);
      Serial.print("Altitude: "); Serial.println(GPS.altitude);
      Serial.print("Satellites: "); Serial.println((int)GPS.satellites);
      Serial.print("Antenna status: "); Serial.println((int)GPS.antenna);
    }
  }
}

Attempts to Fix the code:

Tried changing GPSECHO to false.
This didn't seem to change anything. Still not quite sure what this does.

In the SoftwareSerial Examples:
Note:
Not all pins on the Mega and Mega 2560 support change interrupts,
so only the following can be used for RX:
10, 11, 12, 13, 50, 51, 52, 53, 62, 63, 64, 65, 66, 67, 68, 69
I've tried changing the software serial pins to 10, and 11. Also 50 and 51.

I've tried making this work with the Hardware Serial Example also. Again, same results.

Somewhere between getting the NMEA sentences, and trying to get them to print them out in the serial monitor is where its getting buggered up.

Aren't the Examples supposed to just work?

What am I missing?

i’d put some serial.prints in to see where it’s falling over.

So I need to thank you for the fast reply.

Cause when I went back to the project and double checked my wiring....moved the TX and RX pins to the 10 and 11 pins. Turns out, somehow I had these hooked up backwards. Now it works....lol

Thanks

ATmega 2560 has 3 U(S)ART (TX1=PD3, RX1=PD2 normal used for programming. TX2=PH1=pin13, RX2=PH0=pin12. TX3=PJ1, RX3=PJ0) See here. Why using software serial?

:roll_eyes: Pin 10 is VCC and pin 11 is GND.

This may be true for the actual pins on the Atmega2560, but is not true for the arduino IDE which refers to pins as they are broken out on the board (D10 & D11).

D10 is not the same as pin 10 what is wrote by twiens99.

What say these docs on the official arduino site for pin 10 and 11?

While technically true, it is very common for posts to refer to "pins" by number when, in fact, they are referring to the connector labels printed on whatever board they are using. The arduino core takes care of remapping "pin" numbers used in code to the actual MCU ports/bits.

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