Hi Guys
Im working on two libraries of GPS code one just prints to terminal and the other savs to SD card , but i have a problem that i cant get solved.
the first sketch is the code I want to get working now but cant , and the second sketch is how I want it to work.
My problem is when running the first Sketch my GPS is accurate with in 10-14km ,when I runthe second sketch is accurate to with in a few feet . I have noticed that the first skecth does not have the same amount of decimals after the "." as the second skecth but i dont understand why since they are both set to floats and both Buff size set to 256.
help please ?
//Add the Mikal Hart Libraries
#include <SoftwareSerial.h>
#include <TinyGPS.h>
//Add the SdFat Libraries
#include <SdFat.h>
#include <SdFatUtil.h>
#include <ctype.h>
//Create the variables to be used by SdFat Library
Sd2Card card;
SdVolume volume;
SdFile root;
SdFile file;
#define BUFFSIZE 256
char buffer[BUFFSIZE]; //This will be a data buffer for writing contents to the file.
char in_char=0;
char filename[]="log.txt";
//Intialize TinyGPS and NewSoftSerial
TinyGPS gps;
SoftwareSerial nss(3, 2);
//Intialize GPS variables
float lat , lon ;
float flat , flon , falt;
unsigned long age, date, time, chars;
int year;
byte month, day, hour, minute, second, hundredths;
unsigned short sentences, failed;
bool newdata = false;
bool feedgps();
void setup()
{
Serial.begin(9600);
nss.begin(38400); //GPS's Buad Rate
pinMode(3, INPUT);
pinMode(2, OUTPUT);
pinMode(10, OUTPUT);
pinMode(8, OUTPUT); //LED Pin
digitalWrite(8, LOW); // Ensure LED starts as off
card.init(); //Initialize the SD card and configure the I/O pins.
volume.init(card); //Initialize a volume on the SD card.
root.openRoot(volume); //Open the root directory in the volume.
//Create file with defined filename
file.open(root, filename, O_CREAT | O_APPEND | O_WRITE); //Open or create the file 'name' in 'root' for writing to the end of the file
file.println("yr,mth,day, hr,min,sec, lat, long, alt\n"); //Write the header array to the end of the file.
file.close(); //Close the file.
// flash LED 5 times when setup is finished
for (int i=0; i<4; i++){
digitalWrite(8, HIGH); // set the LED on
delay(1000); // wait for a second
digitalWrite(8, LOW); // set the LED off
}
}
void loop()
{
bool newdata = false; // check if data is coming in
if (feedgps())
newdata = true;
Serial.println(newdata);
if (newdata)
{
//Pull gps data
gps.f_get_position(&flat , &flon , &age);
feedgps(); //used to keep gps "awake"
gps.crack_datetime(&year,&month,&day, &hour,&minute,&second, &hundredths, &age);
feedgps();
falt = gps.f_altitude();
feedgps();
//Break up float values into whole numbers(var) and decimals(var1) to be added to data
int flat1 = (flat - (int)flat) * 10000;
int flon1 = (flon - (int)flon) * 100000;
int alt1 = 0;
if (falt >= 10000000.00){ //when gps cant get altitude
falt = 0; //set to 0
}else{
falt = falt * 1; //cm to feet
alt1 = (falt - (int)falt) * 1;
}
//Create then write the char array "buffer" to the end of the file
file.open(root, filename, O_WRITE | O_APPEND); //Open the file in write mode and append the data to the end of the file.
sprintf(buffer, "%d,%d,%d, %d,%d,%d, %0d.%d , %0d.%d , %0d.%d\n", year,month,day,hour,minute,second,(int)flat,abs(flat1),(int)flon,abs(flon1),(int)falt,abs(alt1));
file.println(buffer); //Write the 'contents' array to the end of the file.
file.close(); //Close the file
//flash LED
digitalWrite(8, HIGH); // set the LED on
delay(500);
digitalWrite(8, LOW); // set the LED off
delay(5000); // wait 10 sec before writing next data point
}
}
bool feedgps()
{
while (nss.available())
{
if (gps.encode(nss.read()))
return true;
}
return false;
}
second sketch.
#include <SoftwareSerial.h>
#include <TinyGPS.h>
#define RXPIN 2
#define TXPIN 3
//Set this value equal to the baud rate of your GPS
#define GPSBAUD 38400
// Create an instance of the TinyGPS object
TinyGPS gps;
// Initialize the NewSoftSerial library to the pins you defined above
SoftwareSerial uart_gps(RXPIN, TXPIN);
// This is where you declare prototypes for the functions that will be
// using the TinyGPS library.
void getgps(TinyGPS &gps);
#include <LiquidCrystal.h> // we need this library for the LCD commands // initialize the library with the numbers of the interface pins
LiquidCrystal lcd(4,5,6,7,8,9); // define our LCD and which pins to user
/*
* setup() - this function runs once when you turn your Arduino on
* We initialize the serial connection with the computer
*/
void setup()
{
Serial.begin(115200); //Start the serial connection with the computer
//to view the result open the serial monitor
lcd.begin(16, 2); // need to specify how many columns and rows are in the LCD unit
lcd.clear(); // this clears the LCD. You can use this at any time
uart_gps.begin(GPSBAUD);
Serial.println("");
Serial.println("GPS in acquisition");
Serial.println("...waiting for lock...");
Serial.println("");
}
void loop() // run over and over again
{
while(uart_gps.available()) // While there is data on the RX pin...
{
int c = uart_gps.read(); // load the data into a variable...
if(gps.encode(c)) // if there is a new valid sentence...
{
getgps(gps); // then grab the data.
}
}
}
// The getgps function will get and print the values we want.
void getgps(TinyGPS &gps)
{
// To get all of the data into varialbes that you can use in your code,
// all you need to do is define variables and query the object for the
// data. To see the complete list of functions see keywords.txt file in
// the TinyGPS and NewSoftSerial libs.
// Define the variables that will be used
float latitude, longitude;
// Then call this function
gps.f_get_position(&latitude, &longitude);
// You can now print variables latitude and longitude
Serial.print("Lat/Long: ");
Serial.print(latitude,5);
Serial.print(", ");
Serial.println(longitude,5);
// Same goes for date and time
int year;
byte month, day, hour, minute, second, hundredths;
gps.crack_datetime(&year,&month,&day,&hour,&minute,&second,&hundredths);
// Print data and time
Serial.print("Date: "); Serial.print(month, DEC); Serial.print("/");
Serial.print(day, DEC); Serial.print("/"); Serial.print(year);
Serial.print(" Time: "); Serial.print(hour, DEC); Serial.print(":");
Serial.print(minute, DEC); Serial.print(":"); Serial.print(second, DEC);
Serial.print("."); Serial.println(hundredths, DEC);
//Since month, day, hour, minute, second, and hundr
// Here you can print the altitude and course values directly since
// there is only one value for the function
Serial.print("Altitude (meters): "); Serial.println(gps.f_altitude());
/* Same goes for course
Serial.print("Course (degrees): "); Serial.println(gps.f_course());
// And same goes for speed
Serial.print("Speed(kmph): "); Serial.println(gps.f_speed_kmph()); */
Serial.println();
// Here you can print statistics on the sentences.
unsigned long chars;
unsigned short sentences, failed_checksum;
gps.stats(&chars, &sentences, &failed_checksum);
//Serial.print("Failed Checksums: ");Serial.print(failed_checksum);
//Serial.println(); Serial.println();
lcd.clear();
lcd.setCursor(0,0);
//lcd.print("Lat/Long: ");
lcd.print(latitude,4);
lcd.print(", ");
lcd.println(longitude,4);
lcd.setCursor(0,1);
//lcd.print("Date: "); lcd.print(month, DEC); lcd.print("/");
// lcd.print(day, DEC); lcd.print("/"); lcd.print(year);
//lcd.print(" Time: ");
lcd.print(hour, DEC); lcd.print(":");
lcd.print(minute, DEC); lcd.print(":"); lcd.print(second, DEC);
lcd.print("."); lcd.print(hundredths, DEC);
}
thank you for any advice
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