Getting weird data from Arduino to Android via Bluetooth

Question

I want to receive simple data from arduino with bluetooth module attached. I am recieving data, everything works fine, but i cant read it well. Here is arduino code:

char incomingByte;

void setup() {
    Serial.begin(9600);

}

void loop() {
  Serial.println(2);
  delay(1000);

}

Here is Android code for reading data from InputStream (BufferedInputStream):

mInStream = socket.getInputStream()

public void run() {
    BufferedReader r = new BufferedReader(new InputStreamReader(mmInStream));

    while (true) {
        try {
            int a = r.read();
            Log.d(TAG, Integer.toString(a));

        } catch (IOException e) {
            break;
        }
    }
}

Here is problem: When Arduino sends number 1, Android should receive it through Buffered Input Reader as decimal value for 1 and it is equal to 49. But i get 2 additional lines in Log, always same values: 10 and 13. How to avoid reading/receiving this? Here is Logcat output for number 1 sent from Arduino:

TAG: 49
TAG: 13
TAG: 10

Whats wrong? Why does Android app receive last two lines?

Answer 1

This is what println() does according to Arduino's Documentation :

Prints data to the serial port as human-readable ASCII text followed by a carriage return character (ASCII 13, or '\\r') and a newline character (ASCII 10, or '\\n').

Use Serial.print() instead.

Answer 2

I will focus on two aspects of the above program.

1. In the above program, two extra tags that are been printed are ASCII Values - 10 for " line feed " and 13 for " carriage return ".
   The Serial.println adds a " carriage return " and " line feed character " to the end of what is being printed. Serial.print doesn't add anything.
   So you can use Serial.print .

2. Also, for the part of reading from InputStream , you can also prefer the following code: link

    BufferedReader r = new BufferedReader(new InputStreamReader(inputStream)); StringBuilder total = new StringBuilder(); String line; while ((line = r.readLine()) != null) { total.append(line).append('\\n'); }