ok, i'm using 3 ping sensors to control RGB in processing, mostly just to get it to work, so I know how to do it for a bigger project at the end of the summer.  the arduino code is working fine, but when i run the processing program, the serial data in the serial monitor in arduino goes bonkers, and i get string out of bounds exceptions in processing.  

arduino code:   Code:

int pingPins [] = {7, 5, 3};

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

void loop()
{
  long duration, inches;

  for (int i=0; i<3; i++)
  {
  pinMode(pingPins[i], OUTPUT);
  digitalWrite(pingPins[i], LOW);
  delayMicroseconds(2);
  digitalWrite(pingPins[i], HIGH);
  delayMicroseconds(5);
  digitalWrite(pingPins[i], LOW);

  // The same pin is used to read the signal from the PING))): a HIGH
  // pulse whose duration is the time (in microseconds) from the sending
  // of the ping to the reception of its echo off of an object.
  pinMode(pingPins[i], INPUT);
  duration = pulseIn(pingPins[i], HIGH);

  // convert the time into a distance
  inches = microsecondsToInches(duration);
  char RGB[] = {'R','G','B'};

 Serial.print(RGB[i]);
 Serial.println(inches);
 
  


  
  }
  
   delay(100);
}

long microsecondsToInches(long microseconds)
{
  // According to Parallax's datasheet for the PING))), there are
  // 73.746 microseconds per inch (i.e. sound travels at 1130 feet per
  // second).  This gives the distance travelled by the ping, outbound
  // and return, so we divide by 2 to get the distance of the obstacle.
  // See: http://www.parallax.com/dl/docs/prod/acc/28015-PING-v1.3.pdf
  return microseconds / 74 / 2;
}
 

Processing code:

Code:

import processing.serial.*;

String buff = "";
int rval = 0, gval = 0, bval = 0;
int NEWLINE = 10;

Serial port;

void setup()
{
  size(200, 200);

  // Print a list in case COM1 doesn't work out
  println("Available serial ports:");
  println(Serial.list());

  //port = new Serial(this, "COM1", 9600);
  // Uses the first available port
  port = new Serial(this, Serial.list()[0], 9600);
}

void draw()
{
  while (port.available() > 0) {
    serialEvent(port.read());
  }
  background(rval, gval, bval);
}

void serialEvent(int serial) 
{ 
  // If the variable "serial" is not equal to the value for 
  // a new line, add the value to the variable "buff". If the 
  // value "serial" is equal to the value for a new line,
  //  save the value of the buffer into the variable "val".
  if(serial != NEWLINE) { 
    buff += char(serial);
  } else {
    // The first character tells us which color this value is for
    char c = buff.charAt(0);
    // Remove it from the string
    buff = buff.substring(1);
    // Discard the carriage return at the end of the buffer
    buff = buff.substring(0, buff.length()-1);
    // Parse the String into an integer
    if (c == 'R')
	rval = Integer.parseInt(buff);
    else if (c == 'G')
	gval = Integer.parseInt(buff);
    else if (c == 'B')
	bval = Integer.parseInt(buff);
    // Clear the value of "buff"
    buff = "";
  }
}

 

thanks!