ms3_arduino.ino

// A simple sketch to read GPS data and parse the $GPRMC string 

// see http://www.ladyada.net/make/gpsshield for more info


// If using Arduino IDE prior to version 1.0,

// make sure to install newsoftserial from Mikal Hart

// http://arduiniana.org/libraries/NewSoftSerial/

#if ARDUINO >= 100

 #include "Arduino.h"

 #include "SoftwareSerial.h"

#else

 #include "WProgram.h"

 #include "NewSoftSerial.h"

#endif


#include <LiquidCrystal.h>


LiquidCrystal lcd(8, 9, 4, 5, 6, 7); 

// Use pins 2 and 3 to talk to the GPS. 2 is the TX pin, 3 is the RX pin

#if ARDUINO >= 100

SoftwareSerial mySerial = SoftwareSerial(2, 3);

#else

NewSoftSerial mySerial = NewSoftSerial(2, 3);

#endif


// Use pin 4 to control power to the GPS

#define powerpin 10


// Set the GPSRATE to the baud rate of the GPS module. Most are 4800

// but some are 38400 or other. Check the datasheet!

#define GPSRATE 4800


// The buffer size that will hold a GPS sentence. They tend to be 80 characters long

// so 90 is plenty.

#define BUFFSIZ 90 // plenty big


// global variables

char buffer[BUFFSIZ];        // string buffer for the sentence

char *parseptr;              // a character pointer for parsing

char buffidx;                // an indexer into the buffer


// The time, date, location data, etc.

uint8_t hour, minute, second, year, month, date;

uint32_t latitude, longitude;

uint8_t groundspeed, trackangle;

char latdir, longdir;

char status;


void setup() 

{ 

  lcd.begin(16, 2);

  lcd.clear();

  lcd.setCursor(0, 0);

  lcd.print("Welcome");

  delay(500);

  
  if (powerpin) {

    pinMode(powerpin, OUTPUT);

  }

  
  // Use the pin 13 LED as an indicator

  pinMode(13, OUTPUT);

  
  // connect to the serial terminal at 9600 baud

  Serial.begin(9600);

  
  // connect to the GPS at the desired rate

  mySerial.begin(GPSRATE);

   
  // prints title with ending line break 

  //Serial.println("GPS parser"); 

 
   //digitalWrite(powerpin, LOW);         // pull low to turn on!

} 

 
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;

  }

}

 
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;

    
    // Input from Android
    
     // wait a second so as not to send massive amounts of data
  char inChar = (char)Serial.read();
  while (inChar == -1) {
      delay(20);
      inChar = (char)Serial.read();
  }
  String inputStr = "";
  while (inChar != -1) {
      delay(10);
      inputStr += (char) inChar;
      inChar = (char)Serial.read();
  }
      //inputStr = "Arduino: replying " + inputStr;
      //Serial.println(inputStr+"\0");
      //Serial.print("Sent back from Arduino.");


  delay(100);

    
    // GPS output to Serial
    //Serial.print("\tLat: "); 

    if (latdir == 'S')

       Serial.print('-');

    else

       Serial.print('+');


    Serial.print(latitude);
    //Serial.print(latitude/1000000, DEC); 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(' ');
    //Serial.print("\tLong: ");

    if (longdir == 'W')

       Serial.print('-');

    else

       Serial.print('+');
     
    Serial.print(longitude);

    //Serial.print(longitude/1000000, DEC); 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('"');

   
  lcd.clear();

  lcd.setCursor(0, 0);

  lcd.print(latitude/1000000);lcd.print('*');lcd.print((latitude/10000)%100);lcd.print('\'');

  lcd.setCursor(8, 0);

  lcd.print(longitude/1000000);lcd.print('*');lcd.print((longitude/10000)%100);lcd.print('\'');
  
  // Display message from Android
  lcd.setCursor(0, 1);
  
  lcd.print(inputStr+"\0");

  delay(200);

  }

  
  //Serial.println(buffer);

}