bluetooth.cpp

/* Include the software serial port library */
#include <SoftwareSerial.h>


/*

On a mac , connect with the bluetooth module like this:

  $  screen /dev/tty.HC-06-DevB

To check the available bluetooth devices :
  
  $ ls /dev/tty.*
  /dev/tty.Bluetooth-Modem	/dev/tty.SerialPort
  /dev/tty.Bluetooth-PDA-Sync	/dev/tty.SerialPort-1
  /dev/tty.HC-06-DevB

Type CTRL-A-D to exit the screen

  [detached]

References 

  http://www.exp-tech.de/service/datasheet/HC-Serial-Bluetooth-Products.pdf
  http://www.ebay.com/itm/HC-05-Bluetooth-Transceiver-Host-Slave-Master-Module-Wireless-Serial-6pin/221303627009?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D18058%26meid%3D2539213225991316226%26pid%3D100011%26prg%3D8304%26rk%3D2%26rkt%3D5%26sd%3D221286562520%26
  https://play.google.com/store/apps/details?id=com.techbitar.android.Andruino
  http://www.instructables.com/id/Cheap-2-Way-Bluetooth-Connection-Between-Arduino-a/?ALLSTEPS

*/

/* DIO used to communicate with the Bluetooth module's TXD pin */
#define BT_SERIAL_TX_DIO 10 
/* DIO used to communicate with the Bluetooth module's RXD pin */
#define BT_SERIAL_RX_DIO 11

/* Initialise the software serial port */
SoftwareSerial BluetoothSerial(BT_SERIAL_TX_DIO, BT_SERIAL_RX_DIO);

char command[20];
int index=0;

void setup()  
{
  /* Set the baud rate for the hardware serial port */
  Serial.begin(9600);
  /* Set the baud rate for the software serial port */
  BluetoothSerial.begin(9600);

Serial.println("Waiting ...");
}

/* Main loop that will pass any data to and from the Bluetooth mode to the
   host PC */
void loop()
{
  
   int photocellReading = analogRead(0);  
 
//  Serial.print("Analog reading = ");
//  Serial.println(photocellReading);     // the raw analog reading
  
  //Serial.println(millis());

  if (millis()%1000==0) {
    // Serial.println("Every sec"); 
    BluetoothSerial.write(reading.c_str());
    //BluetoothSerial.write(photocellReading);
    BluetoothSerial.write("\r\n");  
     
  }
  
  
  String reading = String(photocellReading);
  
  
  /* If data is available from the Bluetooth module then pass it on to the 
     hardware serial port. */
  if (BluetoothSerial.available()) {
    Serial.println("BluetoothSerial.available()");
    int incomingByte = BluetoothSerial.read();
    
    command[index] = incomingByte; // Store it
    index++; // Increment where to write next    
    command[index] = '\0'; // Null terminate the string

    Serial.println(String("User wrote int  : ") + incomingByte);    
    Serial.println(String("User wrote char : ") + (char)incomingByte);
    Serial.write(incomingByte);                  // prints out the letter
    //Serial.println(String(incomingByte));       // prints out the int 
    Serial.println();                           // blank line
    if (incomingByte == 'R') {
      Serial.println("RESET");
    }
    
    if (incomingByte == '\r') {
      Serial.println("Found enter .... the command entered was " + String(command));
      index=0;
    }
    if (incomingByte == '\n') {
      Serial.println("Found linefeed");
    }
    if (incomingByte == '\r\n') {
      Serial.println("Found enter/linefeed");
    }
    
    
    //Serial.write(BluetoothSerial.read());
  }
 
   /* If data is available from the hardware serial port then pass it on 
      to the Bluetooth module. */
  if (Serial.available())
    BluetoothSerial.write(Serial.read());
}