Etch-A-Jer one knob

// Adapted from the Graphing sketch by Jeremy Nir
 

 import processing.serial.*;
 
 PImage img;
 
 Serial myPort;        // The serial port
 int knobby = 1;         // horizontal position of the graph
 
 void setup () {
 // set the window size:
 size(1090, 900);  
 
  img = loadImage("etch-a-jer.png"); 
 
 // List all the available serial ports
 println(Serial.list());
 // I know that the first port in the serial list on my mac
 // is always my  Arduino, so I open Serial.list()[0].
 // Open whatever port is the one you're using.
 myPort = new Serial(this, Serial.list()[8], 9600);
 // don't generate a serialEvent() unless you get a newline character:
 myPort.bufferUntil('\n');
 // set inital background:
 background(#555555);
 }
 void draw () {

   
   
 }
 
 void serialEvent (Serial myPort) {
 // get the ASCII string:
 String inString = myPort.readStringUntil('\n');
 
 if (inString != null) {
 // trim off any whitespace:
 inString = trim(inString);
 // convert to an int and map to the screen height:
 float inByte = float(inString);
 inByte = map(inByte, 0, 1023, 0, height);
 
   image(img, 0, 0);
 
 fill (#000000);
 ellipse (mouseX, height-inByte ,4,4);


 }
}