Receiving Data in Pd from the Arduino

• It is possible to communicate between an Arduino and Pd using the Serial functionality in the Arduino and the [comport] object/library in Pd.

• The following Arduino code sends out a counter number between 0 - 15 every 500 milliseconds.

  int count = 0;
  
  void setup() 
  { 
    Serial.begin( 115200 ); 
  }
   
  void loop() 
  {
    Serial.println( count );
    count += 1;
    if ( count > 15 ) count = 0;
    delay( 500 );
  }
  

• The Pd patch below can be used to read up to 3 space separated values per line feed coming from the serial port. You will need to modify the [unpack] object to support more values.

• IMPORTANT: It is absolutely necessary that the serial baud rate set in the Arduino code be the same as the rate specified to the [comport] object in Pd. Also, you need to close the serial port in Pd when uploading a new program to the Arduino board or when trying to view the serial output from within the Arduino IDE.
  

• To send two or more values out from the Arduino, separate the values by spaces. The Arduino sketch below assumes you are reading two voltage values from analog pins A2 and A3.

  void setup() 
  { 
    Serial.begin( 115200 ); 
  }
   
  void loop() 
  {
    // Read from two analog pins and put a space between values.
    for ( int i=2; i<4; i++) {
      Serial.print( analogRead(i) );
      Serial.print(' ');
    }
    Serial.println();
  
    delay( 300 );  // Delay a bit.
  }