Sensor Workshop at ITP

by Jamie Allen Feb 1st, 2007

This is Processing code (Arduino code commented in at the bottom) for graphing a single piece of data. This code updates Tom's original example by simply scaling the data output based on the size of the screen.

This code might be a good starting point for Sensors and Time assignments, among other things.

/*
Datalogger based on Tom Igoe's 
by Jamie Allen 2007

 This program takes raw bytes from the serial port at 9600 baud and graphs them.
 To start/stop the graph, click the mouse.

Created 20 April 2005
Updated 5 July 2005
 */

import processing.serial.*;

Serial myPort;  // The serial port
PFont myFont;     // The display font: 

// initial variables:
int i = 1;                   // counter
int inByte = -1;             // data from serial port
int wrote = 0;
int offset = 0;
int offsettext = 25;

void setup () {
  size(500, 500);        // window size

  myFont = loadFont("Technine-18.vlw"); 
  textFont(myFont, 16); 
  textAlign(CENTER);
  textMode(SCREEN);
  fill(#E9FF5B, 200);

  // set inital background:
  background(#000000);
  strokeCap(ROUND);


  strokeWeight(3);

  // List all the available serial ports
  println(Serial.list());
  // I know that the third port in the serial list on my mac
  // is always my  Keyspan adaptor, so I open Serial.list()[2].
  // Open whatever port is the one you're using.
  myPort = new Serial(this, Serial.list()[4], 9600);

}

void draw () {

  if (myPort.available() > 0) {
    inByte = myPort.read();
    serialEvent();
  }

}

void serialEvent () {
  // draw the line:

  smooth();

  stroke(#FF7B00+inByte,i/3);

  line(i, height, i, (height - height*(inByte/255.0))+20);

  // at the edge of the screen, go back to the beginning:
  if (i > width) {
    i = 0;
    background(#000000);
  } 
  else {
    i++;
  }

  //only display the value once every 25 readings
  //just to keep things clean 
  if (wrote > 27)
  {
  text(inByte, i, (height - height*(inByte/255.0))+20);
  wrote = 0;
  }
  wrote++;


}



/*

//a simple program to spit data out from Arduino 
//to the above graphing program in Processing

int sensorPin = 5;    // select the input pin for the sensor
int ledPin = 13;   // select the pin for the LED
int val = 0;       // variable to store the value coming from the sensor

void setup() {
  pinMode(ledPin, OUTPUT);  // declare the ledPin as an OUTPUT
  Serial.begin(9600);	// opens serial port, sets data rate to 9600 bps
}

void loop() {
  digitalWrite(ledPin, HIGH);    // sets the LED on
  val = analogRead(sensorPin);    // read the value from the sensor
  //Serial.print("Raw Value: ");  
  //Serial.println(val, DEC);  //send as a ASCII encoded decimal
  Serial.print(val/4, BYTE);  //send as a single byte - a single 8-bit value between 0-255 (1023/4=255) 
  delay(20);
}





*/