Parked Car Finder

// Libraries that I use 
#include <LGPS.h>
#include <LBT.h>
#include <LBTServer.h>

// Create the GPS sentence structure for the GPS component
gpsSentenceInfoStruct info;

// Create the buff variable for the bluetooth component
char buff[256];

// getComma is from the GPS example to seperate the GPS string
static unsigned char getComma(unsigned char num,const char *str)
{
  unsigned char i,j = 0;
  int len=strlen(str);
  for(i = 0;i < len;i ++)
  {
     if(str[i] == ',')
      j++;
     if(j == num)
      return i + 1; 
  }
  return 0; 
}

// getDoubleNumber is from the GPS example to convert the string to a number
static double getDoubleNumber(const char *s)
{
  char buf[10];
  unsigned char i;
  double rev;
  
  i=getComma(1, s);
  i = i - 1;
  strncpy(buf, s, i);
  buf[i] = 0;
  rev=atof(buf);
  return rev; 
}

// getIntNumber is from the GPS example to convert the string to a number
static double getIntNumber(const char *s)
{
  char buf[10];
  unsigned char i;
  double rev;
  
  i=getComma(1, s);
  i = i - 1;
  strncpy(buf, s, i);
  buf[i] = 0;
  rev=atoi(buf);
  return rev; 
}

// I start my setup section
void setup() {
  // I setup my baud rate at 9600 
  Serial.begin(9600);
  // I turn on the GPS section of the Linkit One
  LGPS.powerOn();
  // Tell the serial port that it is on.
  Serial.println("LGPS Power on, and waiting ..."); 
  
  delay(3000);

  // I startup the bluetooth component and tell the serial port it's working
  if(!LBTServer.begin((uint8_t*)"My_BTServer"))
  {
    Serial.println("Fail to start BT.");
    return;
  }
    Serial.println("BT server is started.");
}


void loop() {
  // put your main code here, to run repeatedly:
  Serial.println("LGPS loop"); 
  // I grab the GPS data
  LGPS.getData(&info);
  // I set the variable GPGGAstr to be the info 
  const char* GPGGAstr = (const char*)info.GPGGA;
  
  // I create the variable lat and lon (to get the all the digits)
  double lat = 0;
  double lon = 0;
  // I create the variables latitude and longitude to convert lat and lon
  // and use those string values
  String latitude;
  String longitude;

  // buf and bytesRead is used for the bluetooth portion
  uint8_t buf[64];
  int bytesRead;
  
  int tmp;


  // If something connects to the Linkit One via bluetooth then I can start
  // sending information to the phone
  if(LBTServer.connected())
  {
      // if the start of the GPS string is a $ sign then I know that I grabbed
      // it correctly
      if(GPGGAstr[0] == '$')
      {
        // I set the temporary variable to be the latitude section
        tmp = getComma(2, GPGGAstr);
        // I use the getDoubleNumber to convert that string to a double
        lat = getDoubleNumber(&GPGGAstr[tmp]);
        // I set the temporary variable to be the longitude section
        tmp = getComma(4, GPGGAstr);
        // I use the getDoubleNumber to convert that string to a double
        lon = getDoubleNumber(&GPGGAstr[tmp]);
    
        // I don't need these after I verify it. The String() function
        // can be used to specify the number of digits (in this case 6)
        //Serial.println(String(lat/100,6));
        //Serial.println(String(lon/100,6)); 
        
        // I set the latitude to have 6 digits in the decimal place and
        // at a comma at the end so I can interpret it correctly
        latitude = String(lat/100,6) + ',';
        // I set the longitude to have 6 digits in the decimal place
        // and add a negative sign at the beginning (because the GPS 
        // coordinate doesn't have the negative sign built in
        longitude = '-' + String(lon/100,6);
      
  
        // I set strlen1 to be the size of the latitude string +1
        int strlen1 = latitude.length() + 1;
        // I set strlen2 to be the size of the longitude string +1
        int strlen2 = longitude.length() + 1;
        // I use bufspot for bytesRead portion (bytesRead is the verification
        // that the transmission sent correctly)
        int bufspot = 0;
        // I create two arrays to fill in the buf array
        char chararray1[strlen1];
        char chararray2[strlen2];
        // I use the function toCharArray() to fill in the two arrays I just
        // created.
        latitude.toCharArray(chararray1,strlen1);
        longitude.toCharArray(chararray2,strlen2);
  
        // I create the variable i so that I can use it for the for loop
        int i;
  
      // I start filling out the buf array for the bluetooth transmission
      // I increase the variable bufspot each time I loop
      for (i = 0; i<strlen1; i++) {
        buf[i] = chararray1[i];
        bufspot++;  
      }
  
      // I set the variable buf2 to the value of bufspot
      int buf2 = bufspot;
  
      // I iterate from bufspot to bufspot+strlen2 and I fill
      // out the buf array with the remaining information. I 
      // increase buf2 each time (which will be used to set
      // bytesRead to)
      for (i = bufspot; i < bufspot+strlen2; i++) {
        buf[i] = chararray2[i-bufspot];
        buf2++;
      }
  
      // The last index of the buf array has to be 0 so that the
      // transmission knows when to end
      buf[buf2+1] = 0;
      // I set bytesRead to buf2
      bytesRead = buf2;
  
      // This is an example of what the individual arrays look like
      //buf[0] = 'a';
      //buf[1] = 'b';
      //buf[2] = 'c';
      //buf[3] = 0;
      //bytesRead = 4;
  
      // I write the the serial port so that you can see what's going
      // to be transmitted
      Serial.write(buf, bytesRead);
      // Then I start to transmit to the Server (in this case my phone)
      // the same thing I sent to the Serial port
      LBTServer.write(buf, bytesRead);
  
      // This is all mostly unneccessary because this is the portion where
      // I read back the transmissions from the phone but I will explain it
      // anyway
  
      // while(true) indicates whether or not I've correctly sent the information
      // to the device
      while(true)
      {
        // I set bytesRead to be whatever buf is at the moment (basically 
        // grabbing the transmission)
        bytesRead = LBTServer.readBytes(buf, 64);
  
            // I print back what I read to the Serial port
            Serial.println(bytesRead);
          
            // if I listen to it wrong then I want to break this code and
            // move on
            if(!bytesRead)
            break;
  
        // If the first letter that I read in is a capital S then I'm going
        // to set the buf array with abc
        if (buf[0] == 'S') {          
            buf[0] = 'a';
            buf[1] = 'b';
            buf[2] = 'c';
            buf[3] = 0;
            bytesRead = 4;
            // I'm then going to write to the serial port what I just put
            // together
            Serial.write(buf, bytesRead);
            // And then I'm going to send it to the bluetooth connected 
            // device (in this case my phone)
            LBTServer.write(buf, bytesRead);
        }
        
      } // end of the while(true) portion
  
        // I wait 2 seconds before I can continue looping
        delay(2000);

    }
      // If it doesn't have a $ sign at the beginning then the GPS is not setup
      // correctly
      else
      {
        // I print out that it didn't get received correctly
        Serial.println("Not get data"); 
      }
      
  } // end of the if(LBTServer.connected()) section

  // If the bluetooth is not connected then I want to wait and listen
  // for another connection. If I get one then I will be connected
  else
  {
    LBTServer.accept(5);
  }

} // end of loop() section