arduino processing radar screen

hello,

I'm trying to make a radar screen with processing and an arduino. but I struggle with the communication between the arduino and processing. the goal is to display a radar line on my computer screen with match with the position of the servo. this is what I have got so far. can please somebody help me. (btw sorry for grammar and spelling, I'm dutch)

processing code: import cc.arduino.*; import processing.serial.*;

Arduino arduino;

color bgcolor = color (0,0,0);
color gridcolor = color (0,0,0);
color sweepercolor = color (102,250,81);
float s;
float rond;
float val;
int l;
void setup(){
  size(800, 640);
  arduino = new Arduino(this,"COM3" , 57600);
}

void draw(){
  background(bgcolor);
  grid();
  sweeper();
  circle();
  stipje();
}


 void circle(){
   fill(color (102,250,81,60));
   ellipse(400, 320, 600, 600);
 }

void grid(){
  stroke(#FAF7F7);
  strokeWeight(2);
    line(width/2, height/2, width/2,height/23);            //verticlal grid
    line(width/2, height/2, 700,height/2 );          //horizontal grid
     for(int i = 20; i <300; i+=20){
     line((width/2)+5,i,(width/2)-5,i);
   }
   for(int i = 700; i >400; i-=20){
     line(i, (height/2)+5,i,(height/2)-5 );
}}




void sweeper(){
  rond = map(millis(), 0, 2000, 0, PI);
  strokeWeight(7);
  float f = 0.01;
  for(int i = 38; i>=1; i--){
  stroke(sweepercolor, 2*i);
  line(width/2, height/2, (width/2 + cos(rond-f) * 300), (height/2 + sin(rond-f) * 300));
  f += 0.01;
  }
}

void stipje(){
int n = 200;
  ellipse(n,n, 20, 20);
}

arduino code:

#include <Servo.h>

Servo myservo;  // create servo object to control a servo
                // a maximum of eight servo objects can be created

int pos = 0;    // variable to store the servo position

void setup()
{
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
  Serial.begin(57600);
}


void loop()
{
  for(pos = 0; pos < 180; pos += 1)  // goes from 0 degrees to 180 degrees
  {                                  // in steps of 1 degree
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);
Serial.println(pos);

  }
  for(pos = 180; pos>=1; pos-=1)     // goes from 180 degrees to 0 degrees
  {
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                       // waits 15ms for the servo to reach the position
Serial.println(pos);

}
}