Adapting leo_parsing from Adafruit_GPS library for use with

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farseer1020
 
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Joined: Fri Dec 19, 2014 3:55 pm

Adapting leo_parsing from Adafruit_GPS library for use with

Post by farseer1020 »

Hello,

I am using the ultimate gps breakout board with Teensy 2.0, which uses the the same ATMEGA chip as the Leonardo. Essentially, I am trying to read in the GPS data and output it to serial. The leo_parsing.ino code in the adafruit_gps library should do this.

The GPS can get a fix, however the serial output is all zeros. I am using the software serial setup with the indicated pins in the .ino file. I have commented out the antenna status and firmware lines. Are there any other modifications that I should make to the code? As for wiring, I have ground and vin, to the respective pins, and tx to pin 8, rx to pin 7.

Thanks for the help.

I have attached the code here:

Code: Select all

// 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

//This code is intended for use with Arduino Leonardo and other ATmega32U4-based Arduinos

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

// Connect the GPS Power pin to 5V
// Connect the GPS Ground pin to ground
// If using software serial (sketch example default):
//   Connect the GPS TX (transmit) pin to Digital 8
//   Connect the GPS RX (receive) pin to Digital 7
// If using hardware serial:
//   Connect the GPS TX (transmit) pin to Arduino RX1 (Digital 0)
//   Connect the GPS RX (receive) pin to matching TX1 (Digital 1)

// If using software serial, keep these lines enabled
// (you can change the pin numbers to match your wiring):
SoftwareSerial mySerial(8, 7);
Adafruit_GPS GPS(&mySerial);

// If using hardware serial, comment
// out the above two lines and enable these two lines instead:
//Adafruit_GPS GPS(&Serial1);
//HardwareSerial mySerial = Serial1;

// 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 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
  }

  // if millis() or timer wraps around, we'll just reset it
  if (timer > millis())  timer = millis();

  // approximately every 2 seconds or so, print out the current stats
  if (millis() - timer > 2000) { 
    timer = millis(); // reset the timer
    
    Serial.print("\nTime: ");
    Serial.print(GPS.hour, DEC); Serial.print(':');
    Serial.print(GPS.minute, DEC); Serial.print(':');
    Serial.print(GPS.seconds, DEC); Serial.print('.');
    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);
    }
  }
}

User avatar
Franklin97355
 
Posts: 23910
Joined: Mon Apr 21, 2008 2:33 pm

Re: Adapting leo_parsing from Adafruit_GPS library for use w

Post by Franklin97355 »

According to Teensy documentation:
Real UART Serial

The hardware UART Serial port should always be used, if possible, before considering SoftwareSerial. On Teensy, the hardware UART serial port completely separate from the USB port.
On Arduino boards, the main hardware serial port is used for programming and sending messages to the Arduino Serial Monitor. Many projects and website may advise you to use SoftwareSerial or NewSoftSerial to communicate with serial devices, like GPS modules or Modbus controllers. This is necessary on Arduino Uno, because there is no unused hardware UART serial port.

Teensy does have a hardware UART serial port available. Using the real hardware UART serial port provides much better performance and avoids SoftwareSerial's many issues.

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