GPS Module Code

GPS_Example.ino

#include <SoftwareSerial.h>


/***********************************************************************
  Copyright (c) 2015 Vishnu M Aiea
  Original Source : www.rhydoLabz.com
  Date created : 06-02-2015
  Last modified : 06-02-2015
  Contact : [email protected]
  Website : www.vishnumaiea.in

  The following program is useful for monitoring Location data and
  velocity data from a GPS module with UART through a serial monitor.
  The module used here is from www.rhydolabz.com and the part number
  is 'GPS-2261'. The module has the MediaTek MT3329 chipset which uses
  the standard NMEA 0183 output format.

  This program prints Latitude and Longitude in DMS format along with
  directions and speed in knots.

  The original code is from the rhydoLabz website and I modified it
  for monitoring minimum location/transit data.

***********************************************************************/
SoftwareSerial gpsSerial(13, 12); //Rx and Tx

int byte_buffer; // receive serial data byte
unsigned int finish = 0;  // indicates end of message
unsigned int pos_cnt = 0;  // position counter
unsigned int lat_cnt = 0;  // latitude data counter
unsigned int log_cnt = 0;  // longitude data counter
unsigned int spd_cnt = 0;  //speed data counter
unsigned int flag = 0;  // GPS flag
unsigned int com_cnt = 0;  // comma counter

char latitude[20];   // latitude array
char longitude[20];  // longitude array
char GPS_speed[10];  // GPS speed array
char lat_dir; // latitude direction
char long_dir; // longitude direction

void setup() {
  Serial.begin(9600);   // opens serial port, sets data rate to 9600 bps
  gpsSerial.begin(9600);
}

void loop() {
  Receive_GPRMC();
  Serial.print("Latitude = ");
  Serial.println(latitude);
  Serial.print("Lat Direction = ");
  Serial.println(lat_dir);
  Serial.print("Longitude = ");
  Serial.println(longitude);
  Serial.print("Long Direction = ");
  Serial.println(long_dir);
  Serial.print("Speed = ");
  Serial.println(GPS_speed);
  Serial.println();
  finish = 0;
  pos_cnt = 0;
}

void Receive_GPRMC() {
  while (finish == 0) {
    while (gpsSerial.available() > 0) { // Check GPS data
      byte_buffer = gpsSerial.read();
      Serial.println(byte_buffer);
      flag = 1;

      if ( byte_buffer == '$' && pos_cnt == 0)  // finding GPRMC header
        pos_cnt = 1;

      if ( byte_buffer == 'G' && pos_cnt == 1)
        pos_cnt = 2;

      if ( byte_buffer == 'P' && pos_cnt == 2)
        pos_cnt = 3;

      if ( byte_buffer == 'R' && pos_cnt == 3)
        pos_cnt = 4;

      if ( byte_buffer == 'M' && pos_cnt == 4)
        pos_cnt = 5;

      if ( byte_buffer == 'C' && pos_cnt == 5)
        pos_cnt = 6;

      if ( pos_cnt == 6 && byte_buffer == ',') { // count commas in message
        com_cnt++;
        flag = 0;
      }

      if (com_cnt == 3 && flag == 1) {
        latitude[lat_cnt++] =  byte_buffer; // Latitude
        flag = 0;
      }

      if (com_cnt == 4 && flag == 1) {
        lat_dir =  byte_buffer; // Latitude Direction N/S
        flag = 0;
      }

      if (com_cnt == 5 && flag == 1) {
        longitude[log_cnt++] =  byte_buffer; // Longitude
        flag = 0;
      }

      if (com_cnt == 6 && flag == 1) {
        long_dir =  byte_buffer; // Longitude Direction E/W
        flag = 0;
      }

      if (com_cnt == 7 && flag == 1) {
        GPS_speed[spd_cnt++] =  byte_buffer; // Speed in knot
        flag = 0;
      }

      if ( byte_buffer == '*' && com_cnt >= 7) { // end of GPRMC message
        com_cnt = 0;
        lat_cnt = 0;
        log_cnt = 0;
        spd_cnt = 0;
        flag     = 0;
        finish  = 1;

      }
    }
  }
}