Hi, not quite sure where to post my first query but here seemed like a likely candidate. I have been having a lot of fun with Arduino and have come across a project

http://pscmpf.blogspot.com.au/2008/12/arduino-lm35-sensor.html

that uses Processing to create a visual representation of temperature readings from a LM35 sensor. I am not sure how the forum likes code pasted but I am sure a kind Mod will advise me.

import processing.serial.*;

//init variables

Serial commPort;

float tempC;

float tempF;

int yDist;

PFont font12;

PFont font24;

float[] tempHistory = new float[100];

 

void setup()

{

  //setup fonts for use throughout the application

  font12 = loadFont("Verdana-12.vlw");

  font24 = loadFont("Verdana-24.vlw");

 

   //set the size of the window

  size(210, 200);

 

  //init serial communication port

  commPort = new Serial(this, "COM10", 9600);

 

  //fill tempHistory with default temps

  for(int index = 0; index<100; index++)

    tempHistory[index] = 0;

}

 

void draw()

{

  //get the temp from the serial port

  while (commPort.available() > 0)

  {

    tempC = commPort.read();

 

    //refresh the background to clear old data

    background(123);

 

    //draw the temp rectangle

    colorMode(RGB, 160);  //use color mode sized for fading

    stroke (0);

    rect (49,19,22,162);

    //fade red and blue within the rectangle

    for (int colorIndex = 0; colorIndex <= 160; colorIndex++)

    {

      stroke(160 - colorIndex, 0, colorIndex);

      line(50, colorIndex + 20, 70, colorIndex + 20);

    }

   

    //draw graph

    stroke(0);

    fill(255,255,255);

    rect(90,80,100,100);

    for (int index = 0; index<100; index++)

    { 

      if(index == 99)

        tempHistory[index] = tempC;

      else

        tempHistory[index] = tempHistory[index + 1];

      point(90 + index, 180 - tempHistory[index]);

    }

 

    //write reference values

    fill(0,0,0);

    textFont(font12);

    textAlign(RIGHT);

    text("212 F", 45, 25);

    text("32 F", 45, 187);

 

    //draw triangle pointer

    yDist = int(160 - (160 * (tempC * 0.01)));

    stroke(0);

    triangle(75, yDist + 20, 85, yDist + 15, 85, yDist + 25);

 

    //write the temp in C and F

    fill(0,0,0);

    textFont(font24);

    textAlign(LEFT);

    text(str(int(tempC)) + " C", 115, 37);

    tempF = ((tempC*9)/5) + 32;

    text(str(int(tempF)) + " F", 115, 65);

  }

}

When I run the Processing code and upload the Arduino code I get this notification -

WARNING:  RXTX Version mismatch

            Jar version = RXTX-2.2pre1

            native lib Version = RXTX-2.2pre2

 

I have not as yet constructed my circuit, but I thought that I would just see if the code would compile, which it does. The Processing window that opens when I run the sketch is displaying the temperature graphic, which is presumably reacting to the fluctuating voltage on the open analog pin of the Arduino. Is the error that I described above of any consequence or not. Thank you for taking the time to read this. Pedro.