cds_test.pde

import processing.serial.*;

Serial port;
int y0 = 200;
boolean draw_flag = true;

int t = 0;
int data;

void draw_axis() {
  stroke(0);
  line(0, y0, width, y0);
}

void plot_data(int data, char c) {
  if (c == 'r') stroke(255, 0, 0);
  strokeWeight(2);
  point(t, y0 - map(data, 0, 255, 0, y0));
  strokeWeight(1);
}

void setup() {
  size(500, 230);
  port = new Serial( this, "/dev/cu.usbmodem1421", 9600);
}

void draw() {
  if (draw_flag) {
    if (t == 0) {
      background(0);
      draw_axis();
    }
    plot_data(data, 'r');
    t = (t+1) % width;
    println( data );
  }
}

void mouseClicked() {
  draw_flag = !draw_flag;
}

void serialEvent(Serial p) {
  data = port.read();
}