import processing.serial.*;
Serial myPort;
int r;
void setup() { size(600, 600); // window size
randomSeed(second()); // initialize random number
r = width;
println(Serial.list());
myPort = new Serial(this, Serial.list()[2], 9600);
myPort.bufferUntil('\n'); // store data in buffer
}
void draw() { background(255);
fill(random(0,255), random(0,255), random(0,255)); // fill with random color
ellipse(width/2, height/2, r, r); // draw a circle
line(width/2, 0, width/2, height); // draw a line
line(0, height/2, width, height/2); // draw a line
fill(0, 120); // black, transparency 120
textAlign(CENTER, CENTER);
textSize(r/2);
text(r, width/2, height/2); // express distance in the window (스케치 실행창에 거리측정값 표현)
}
void serialEvent(Serial p) { // Read Serial port value
String response = p.readStringUntil('\n').trim(); // Read Stored Data
r = int(response);
r = constrain(r, 5, width) ; // r is MIN: 5 ~ MAX: width
}