Read NMEA strings over serial port with MT3329 and Arduino Mega 2560

i trying read nmea strings otput mt3329 gps mediatek. code have written of strings output , rest first character in string.

example:

code: [select]



returned gps datagps buffer: gprmc,001027.035,v,,,,,0.00,0.00,060180,,,n*40
end
getting gps data
unlocked
locked
returned gps datagps buffer: g
end
getting  gps data
unlocked
locked
returned gps datagps buffer: gpgsv,1,1,00*79


there supposed other strings titles of gpgga , gpgsa part of string output 'g'.

i using arduino mega , connecting gps serial1. have left en pin on gps unconnected since i'm not sure does.

here code:

code: [select]

// arduino mega 2560 r3

#include <string.h>

#define dbg(str) serial.print(str)
#define portgps serial1


long int timergps = 0;
int returnedgps = 0;
int lockedgps = 1;
char buffgps[50];
int igps = 0;

void setup(){

  serial.begin(9600); // arduino computer
  dbg("debug port 0 initialized\n");
  portgps.begin(38400); // mt3328 arduino
  dbg("peripheral port initialized\n");

}

#define timeout 5000

void loop(){
  returnedgps = 0;
  timergps = millis();
  dbg("getting gps data\n");
  while((millis() - timergps < timeout) && !returnedgps){
    getgps();
  }
  if(!returnedgps){
    dbg("gps timed out!\n");
  }else dbg("returned gps data");
  dbg("gps buffer: ");
  dbg(buffgps);
  dbg("\nend\n");
}

void getgps(){
  int inbyte;
  if(portgps.available()){
    inbyte = portgps.read();
  }
  if(lockedgps){
    if(inbyte == 36) {
      dbg("unlocked\n");
      lockedgps = 0;
      igps = 0;
    }
  }
  else{
    if(inbyte == 10){
      dbg("locked\n");
      lockedgps = 1;
      returnedgps = 1;
    }
    else buffgps[igps] = inbyte;
    igps++;
  }
}

i think wrong in code. maybe hardware. i'm not sure.


thanks suggestions!

i suggest use tinygps12 library mikal hart... it's whole lot easier parsing gps data on own. works me..
i suggest find out en pin might important

Arduino Forum > Using Arduino > Networking, Protocols, and Devices (Moderator: fabioc84) > Read NMEA strings over serial port with MT3329 and Arduino Mega 2560

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