code_ultrasonic_sensor_still.txt

Example4
Ping))) ultrasonic distance sensor

The code is exactly the same as for first distance sensor, except the last two lines, which I deleted 
(this changes mandala like graphics into radar screen-like one).

Adopted idea with the original code:
http://webzone.k3.mah.se/projects/arduino-workshop/projects/arduino_meets_processing/instructions/ultrasound.html
and 
http://arduino.cc/en/Tutorial/Ping

********************************************************************
Arduino code:
********************************************************************

 /* Ultrasonic Sensor
 *
 * Reads values (00014-01199) from an ultrasound sensor (3m sensor)
 * and writes the values to the serialport.
 */
 
int ultraSoundSignal = 7; // Ultrasound signal pin
int val = 0;
int ultrasoundValue = 0;
int timecount = 0; // Echo counter
int ledPin = 13; // LED connected to digital pin 13

void setup() {
  Serial.begin(9600);            // Sets the baud rate to 9600
  pinMode(ledPin, OUTPUT);       // Sets the digital pin as output
}

void loop() {
 timecount = 0;
 val = 0;
 pinMode(ultraSoundSignal, OUTPUT); // Switch signalpin to output

// Send low-high-low pulse to activate the trigger pulse of the sensor

digitalWrite(ultraSoundSignal, LOW); // Send low pulse
delayMicroseconds(2); // Wait for 2 microseconds
digitalWrite(ultraSoundSignal, HIGH); // Send high pulse
delayMicroseconds(5); // Wait for 5 microseconds
digitalWrite(ultraSoundSignal, LOW); // Holdoff

// Listening for echo pulse
 
pinMode(ultraSoundSignal, INPUT); // Switch signalpin to input
val = digitalRead(ultraSoundSignal); // Append signal value to val
while(val == LOW) { // Loop until pin reads a high value
  val = digitalRead(ultraSoundSignal);
}

while(val == HIGH) { // Loop until pin reads a high value
  val = digitalRead(ultraSoundSignal);
  timecount = timecount +1;            // Count echo pulse time
}

//Writing out values to the serial port

ultrasoundValue = timecount; // Append echo pulse time to ultrasoundValue

Serial.write('A'); // Example identifier for the sensor
Serial.print(ultrasoundValue);
Serial.write(10);
//serialWrite(13);

// Light up LED if any value is passed by the echo pulse

if(timecount > 0){
  digitalWrite(ledPin, HIGH);
}

// Delay of the program

delay(100);
} 

**************************************************************
Processing code:
**************************************************************

import processing.serial.*;

  float x1,y1,x2,y2,a,ai,b,bi,theta;  // cord parameters
  float H,S,B,Hi,Si,Bi;  // color parameters
  int fr;
  
   
  // variables for the serial port connection object
  Serial port;
  String portname = "/dev/ttyUSB0";  // find the name of your serial port in your system setup!
  int baudrate = 9600;  //  set baudrate
  int value;  // variables used to store value from serial port
  String buf=""; // String buffer to store serial values
  int value1;  // value1 is the read value
  int speedrate=100;
  float range=2.7;  //works well between 2.5 and 3.5
  int t=2;  //scales up the circle range


// the serial event function takes the value of the event and store it in the corresponding variable
void serialEvent(int serial)

{
    if(serial!=10) {        
          buf += char(serial);          
          } else {
          buf = buf.substring(1,buf.length());   //extract the value from the string 'buf'
          value1 = int(buf);    //cast the value to an integer
          buf="";
      }
     }
// initialize display and serial port objects
void setup(){
  
  size(500,500,P2D);
  fr=80;
  frameRate(fr);
  smooth();
  a=b=0.0;
  ai=bi=0.01;
  H=0; S=100; B=100; Hi=1; Si=0; Bi=0;

      port = new Serial(this, portname, baudrate);
      println(port);
     }

// draw listens to serial port, draw 
void draw(){
  
  while(port.available() > 0){
        value = port.read();
        serialEvent(value);
    }
if(value1/t > width){
       value1 = width*2;  // range is set to 1200 mm (equivalent to 1200 pixels). Higher causes flickering
   }
     
  // center and scale
  translate(width/2,height/2);
  scale(width/2);
   
  // initialize color
  colorMode(RGB);
  background(0);
  colorMode(HSB,360,100,100);
   
  // draw 360 cords around a circle
    for(float i=value1/range;i<360;i++){
    theta=(float)i*PI/180;
    x1=sin(theta);
    y1=cos(theta);
    x2=sin(b*theta); 
    y2=cos(a*theta);
    
     
    // each cord gets color in wheel
    H=i;
    stroke(H,S,B);
    line(x1,y1,x2,y2);
    
    }
  }