// A simple sketch to read GPS data and parse the $GPRMC string
// see http://www.ladyada.net/make/gpsshield for more info
// tiny tweaks by buzz.
#include <NewSoftSerial.h>
#define rxPin 2
#define txPin 3
NewSoftSerial mySerial = NewSoftSerial(rxPin,txPin);
//#define powerpin 4
#define GPSRATE 9600
//#define GPSRATE 38400
// GPS parser for 406a
#define BUFFSIZ 90 // plenty big
char buffer[BUFFSIZ];
char *parseptr;
char buffidx;
uint8_t hour, minute, second, year, month, date;
uint32_t latitude, longitude;
uint8_t groundspeed, trackangle;
char latdir, longdir;
char status;
void setup()
{
//if (powerpin) {
// pinMode(powerpin, OUTPUT);
//}
pinMode(rxPin, INPUT);
pinMode(txPin, OUTPUT);
digitalWrite(txPin, HIGH);
pinMode(13, OUTPUT);
Serial.begin(GPSRATE);
mySerial.begin(GPSRATE);
// prints title with ending line break
Serial.println("GPS parser");
// digitalWrite(powerpin, LOW); // pull low to turn on!
}
void loop()
{
uint32_t tmp;
//Serial.print("\n\rread: ");
readline();
// check if $GPRMC (global positioning fixed data)
if (strncmp(buffer, "$GPRMC",6) == 0) {
// hhmmss time data
parseptr = buffer+7;
tmp = parsedecimal(parseptr);
hour = tmp / 10000;
minute = (tmp / 100) % 100;
second = tmp % 100;
parseptr = strchr(parseptr, ',') + 1;
status = parseptr[0];
parseptr += 2;
// grab latitude & long data
// latitude
latitude = parsedecimal(parseptr);
if (latitude != 0) {
latitude *= 10000;
parseptr = strchr(parseptr, '.')+1;
latitude += parsedecimal(parseptr);
}
parseptr = strchr(parseptr, ',') + 1;
// read latitude N/S data
if (parseptr[0] != ',') {
latdir = parseptr[0];
}
//Serial.println(latdir);
// longitude
parseptr = strchr(parseptr, ',')+1;
longitude = parsedecimal(parseptr);
if (longitude != 0) {
longitude *= 10000;
parseptr = strchr(parseptr, '.')+1;
longitude += parsedecimal(parseptr);
}
parseptr = strchr(parseptr, ',')+1;
// read longitude E/W data
if (parseptr[0] != ',') {
longdir = parseptr[0];
}
// groundspeed
parseptr = strchr(parseptr, ',')+1;
groundspeed = parsedecimal(parseptr);
// track angle
parseptr = strchr(parseptr, ',')+1;
trackangle = parsedecimal(parseptr);
// date
parseptr = strchr(parseptr, ',')+1;
tmp = parsedecimal(parseptr);
date = tmp / 10000;
month = (tmp / 100) % 100;
year = tmp % 100;
Serial.print("\nTime(gmt): ");
Serial.print(hour, DEC); Serial.print(':');
Serial.print(minute, DEC); Serial.print(':');
Serial.println(second, DEC);
Serial.print("Date (d/m/y):");
Serial.print(date, DEC); Serial.print('/');
Serial.print(month, DEC); Serial.print('/');
Serial.println(year+2000, DEC);
Serial.print("Lat: ");
if (latdir == 'N')
Serial.print('+');
else if (latdir == 'S')
Serial.print('-');
Serial.print(latitude/1000000, DEC); Serial.print("deg "); Serial.print(' ');
Serial.print((latitude/10000)%100, DEC); Serial.print('\''); Serial.print(' ');
Serial.print((latitude%10000)*6/1000, DEC); Serial.print('.');
Serial.print(((latitude%10000)*6/10)%100, DEC); Serial.println('"');
Serial.print("Long: ");
if (longdir == 'E')
Serial.print('+');
else if (longdir == 'W')
Serial.print('-');
Serial.print(longitude/1000000, DEC); Serial.print("deg "); Serial.print(' ');
Serial.print((longitude/10000)%100, DEC); Serial.print('\''); Serial.print(' ');
Serial.print((longitude%10000)*6/1000, DEC); Serial.print('.');
Serial.print(((longitude%10000)*6/10)%100, DEC); Serial.println('"');
}
//Serial.println(buffer);
}
uint32_t parsedecimal(char *str) {
uint32_t d = 0;
while (str[0] != 0) {
if ((str[0] > '9') || (str[0] < '0'))
return d;
d *= 10;
d += str[0] - '0';
str++;
}
return d;
}
void readline(void) {
char c;
buffidx = 0; // start at begninning
while (1) {
c=mySerial.read();
if (c == -1)
continue;
// Serial.print(c);
if (c == '\n')
continue;
if ((buffidx == BUFFSIZ-1) || (c == '\r')) {
buffer[buffidx] = 0;
return;
}
buffer[buffidx++]= c;
}
}