EM-406 GPS accuracy problems

Forum 2005-2010 (read only) Hardware Interfacing
1

I am trying to read the lat and long off of my EM406 that I put onto one of my custom PCBS. There seems to be a glitch when I pull it up in the serial monitor. It seems to give me random readings when I try and take it out to 7 decimal places. If I tell it to give me two decimal places it will give an actual reading but still isnt accurate enough for what im trying to do. Here is the reading on the serial monitor when I set it as 7.

Lat: 63 Lon: 211301422203

The code:

#include <NewSoftSerial.h>
#include "TinyGPS.h"

TinyGPS gps;
NewSoftSerial GPS(5, 4);

float flat, flon;
unsigned long fix_age, time, date, speed, course;
unsigned long chars;
unsigned short sentences, failed_checksum;

void getgps(TinyGPS &gps);
void printFloat(double f, int digits = 7);
void setup() {

  Serial.begin(115200);
  GPS.begin(4800);
 
}

void loop()

{
  if (GPS.available() > 0){  
    char c = GPS.read();

    if (gps.encode(c))
    {
      gps.f_get_position(&flat, &flon, &fix_age);
      Serial.print("Lat: "); Serial.print(flat, 7); Serial.print(" ");
      Serial.print("Lon: "); Serial.print(flon, 7); Serial.println();
    }
  }
}
2

Here is a link to a picture of the board im working with:

1600×1063 227 KB

3

The number of decimal places displayed has nothing to do with the accuracy of the value stored in memory. There is a limit to the accuracy of the value being stored, though.

From http://arduino.cc/en/Reference/Float

Floats have only 6-7 decimal digits of precision.

What is it that you are doing with the printed value that needs so many decimal places displayed?