Black and white, FM polargraph

/* sends shades in single waves, using an int, to keep track of total steps made per row (x axis).
As per "Jose" sketch, but with arduino section included
Arduino section is included at the bottom within comment tags
 */


import processing.serial.* ;
Serial myPort;
PImage img1;

int Ysize = 6; // height of the rows
int squareSize = 900; // size of the working frame**********************
float greyscalein; // inward greyscale reading of 0- 255
byte greyscaleround; // converted and rounded down to whole bytes for transmission (0 - 9)
int xprogress = 0; // integer for keeping track of progress across image
int stepsize = 0; // integer for transmitting how far to move the motors per step
int y = 0;

void setup() {
  println(Serial.list());
  myPort = new Serial(this, Serial.list()[0], 9600);


  println("Starting up!");
  myPort.clear(); //this is necessary because the arduino keeps sending 42 even before we connect, when we connect the arduino gets reset but since we still see some 42s in our buffer we send it characters to echo too soon (before it reboots) and we will wait forever for it to reply
  println("Waiting for arduino");
  long startWaiting = millis();
  while (myPort.read ()!= 6) {
    delay(50);
    print('.');
  } //wait for the arduino to start sending 42 after reset, the delay is there so we don't use 100% CPU
  println("\nGot a message from the arduino after "+(millis()-startWaiting) + " milliseconds");
  myPort.write(6); //send something to the arduino so it knows that communication has been established
  myPort.clear(); //clear the buffer just in case there was more that one byte in the buffer
  delay(300); //wait for the arduino to get our message and get to the echo loop

  size(squareSize * 2, squareSize); // frame is twice image width. Original image on the left, processed image on the right.
}


void waitUntil(Serial port, int byteValue) {

  if (byteValue>255) throw new IllegalArgumentException("byte value out of range 0-255");

  int lastValue = -1;

  while (lastValue!=byteValue) {
    if (port.available()>0) {
      lastValue=port.read();
    }
    delay(5);// I added this delay so the sketch doesn't use 100% CPU but it's not essential
  }
}

void draw() {

  background(0); // background - 0 is black
  img1 = loadImage("photo3.jpg"); // image, 300 x 300 (STRS or grad)*****************
  imageMode(CENTER);
  image(img1, (squareSize/2), (squareSize/2)); // draws the image, centred

  for (int y = 0; y < squareSize; y = y + Ysize ) {

    for (int x = 0; x < squareSize; x = x + stepsize) {




      color c = get(xprogress, y + Ysize/2);
      float greyscalein = brightness(c);  // Sets 'greyscale' to 255-0

      greyscalein = map(greyscalein, 50, 220, 49, 57); // maps the resolution of the transmited data from 0-255, to 1- 9 ASCII *** white limit and black limit probably need adjusting
      greyscalein = constrain(greyscalein, 49, 57);

      int greyscaleround = round(greyscalein); // rounds the floating value of the greyscalein(read from c) to a whole number (greyscaleround)

      stepsize = ((greyscaleround - 48));// rounds the value to nearest integer

      if (stepsize == 9) {
        xprogress = xprogress + 1;
      }
      else if (stepsize < 9)
      {
        xprogress =  xprogress + (stepsize*2); // adjusts stepsize
      }
      x = xprogress; // clarifies  purely for the serial monitor output

      myPort.write(greyscaleround);
      println("Sending stepsize: " + stepsize );
      waitUntil(myPort, 6);
      println("Received confirmation for "+ stepsize);
      print("X "+ x);
      println(": Y "+ (y+(Ysize/2)));
    }

    myPort.write(13);
    println("Back");
    waitUntil(myPort, 6);
    println("Received confirmation for Back");
    y = y+Ysize;


    for (int x = squareSize; x > 0; x = x - stepsize) {

      color c = get(xprogress, y + Ysize/2);
      float greyscalein = brightness(c);  // Sets 'greyscale' to 255-0

      greyscalein = map(greyscalein, 50, 220, 49, 57); // maps the resolution of the transmited data from 0-255, to 1- 9 ASCII *** white limit and black limit probably need adjusting
      greyscalein = constrain(greyscalein, 49, 57);

      int greyscaleround = round(greyscalein); // rounds the floating value of the greyscalein(read from c) to a whole number (greyscaleround)

      stepsize = ((greyscaleround - 48));// rounds the value to nearest integer

      if (stepsize == 9) {
        xprogress = xprogress - 1;
      }
      else if (stepsize < 9)
      {
        xprogress =  xprogress - (stepsize*2); // adjusts stepsize
      }
      x = xprogress; // clarifies  purely for the serial monitor output

      myPort.write(greyscaleround);
      println("Sending stepsize: " + stepsize );
      waitUntil(myPort, 6);
      println("Received confirmation for "+ stepsize);
      print("X "+ x);
      println(": Y "+ (y+(Ysize/2)));
    }

    myPort.write(10);
    println("Forward");
    waitUntil(myPort, 6);
    println("Received confirmation for Forward");

    if (y >= squareSize-(Ysize)) { // "end of image command". this would be the place to put a signature perhaps?
      myPort.write(4);
      println("End, press to restart");
      waitUntil(myPort, 6);
      println("Received confirmation for End");
    }
  }
}



/* Arduino Section **********************************************

#include <AFMotor.h>

AF_Stepper motorL(200, 1);  // Left Motor, M1 & M2
AF_Stepper motorR(200, 2);  // Right Motor, M3 & M4
// Forward is Up on both motors.

const int button = 2; // button holds the sketch in setup, until pressed.
const int LED = 14; // LED indicates end of sketch

const int pixelsize = 6; // size of a row height, in motor steps EVEN numbers ONLY (10 works well)
const int multiplier = 1; // adjust the multiplier to scale the image; 3 works well on a 300 pix image

int incomingByte = 0;
int x = 0;
int y  = 0;
int currstep = 0; // curr pixel shade 0 - 255?
int direc = 10; // defines direction

void setup() {

  pinMode (LED, OUTPUT);
  pinMode (button, INPUT);

  motorL.setSpeed(30);  // 10 rpm
  motorR.setSpeed(30);  // 10 rpm

  Serial.begin(9600);  // Serial at 9600 bps

  while (digitalRead (button) == HIGH){
    digitalWrite (LED,HIGH); // indicator LED
    // stops script. Its waiting for a button press (LOW on "button")
  }
  digitalWrite (LED,LOW); // indicator LED

  motorR.step(300*multiplier, BACKWARD, SINGLE); //steps from centre, to starting corner
  motorL.step(300*multiplier, BACKWARD, SINGLE); //steps from centre, to starting corner

  while (digitalRead (button) == HIGH){
    digitalWrite (LED,HIGH); // indicator LED
    // stops script. Its waiting for a button press (LOW on "button")
  }

  digitalWrite (LED,LOW); // indicator LED
  while (Serial.available() <= 0) {//keep sending until we get some bytes from the pc
    Serial.write(6);   // just a constant
    delay(100);
  }
  while(Serial.available()>0) Serial.read(); //immediately after we get something from the PC clear the input buffer by reading from it until it's empty
}


void loop() {

  // if we get a valid byte, read analog ins:
  if (Serial.available()>0) {
    incomingByte=Serial.read();

    if (incomingByte == 4) { // end sketch


      motorL.step(x, BACKWARD, SINGLE);  //steps up full pixel
      motorR.step(y, BACKWARD, SINGLE);  //steps up full pixel
      x = 0;
      y = 0;

      digitalWrite (LED,HIGH); // indicator LED
      while (digitalRead (button) == HIGH){
        // stops script. Its waiting for a button press (LOW on "button")
      }
      Serial.write(6);//respond
    }

    else if (incomingByte == 10) { // Forward (LF)
      motorR.step(((pixelsize)*multiplier), FORWARD, SINGLE);  //steps up full pixel
      direc = 10;
      x = 0;
      y = y + pixelsize;
      Serial.write(6);//respond
    }
    else if (incomingByte == 13) { // Backward (CR)
      motorR.step(((pixelsize)*multiplier), FORWARD, SINGLE);  //steps up full pixel
      direc = 13;
      y = y + pixelsize;
      Serial.write(6);//respond
    }

    else    {

      if (direc == 10){ // forward row

        currstep = map(incomingByte, 49, 57, 1 , 9); // map the shade byte between 1 and 9 (1 is black)

        if (currstep >= 9) {
          motorL.step((1*multiplier),FORWARD, SINGLE);
          x = (x + 1);
        }

        else if (currstep < 9) {
          motorR.step(((pixelsize/2)*multiplier), BACKWARD, SINGLE); // from centre steps down half a pixel
          motorL.step((((currstep))*multiplier), FORWARD, SINGLE); // appropriate shade step
          motorR.step(((pixelsize)*multiplier), FORWARD, SINGLE);  //steps back up full pixel
          motorL.step((((currstep))*multiplier), FORWARD, SINGLE);// appropriate shade step
          motorR.step(((pixelsize/2)*multiplier), BACKWARD, SINGLE); // steps down half pixel
          x = (x + (currstep * 2));

        }
        Serial.write(6);//respond
      }


      if (direc == 13){ // backward row
        currstep = map(incomingByte, 49, 57, 1 , 9); // map the shade byte between 1 and 9 (1 is black)

        if (currstep >= 9) {
          motorL.step((1*multiplier),BACKWARD, SINGLE);
          x = (x - 1);
        }

        else if (currstep < 9) {
          motorR.step(((pixelsize/2)*multiplier), BACKWARD, SINGLE); // from centre steps down half a pixel
          motorL.step((((currstep))*multiplier), BACKWARD, SINGLE); // appropriate shade step
          motorR.step(((pixelsize)*multiplier), FORWARD, SINGLE);  //steps back up full pixel
          motorL.step((((currstep))*multiplier), BACKWARD, SINGLE);// appropriate shade step
          motorR.step(((pixelsize/2)*multiplier), BACKWARD, SINGLE); // steps down half pixel
          x = (x - (currstep * 2));
        }
        Serial.write(6);//respond
      }
    }
  }
}