Visualising sensor data using Arduino and Processing

In this Project, we first see how to interface a temperature sensor to an arduino. Later we would send this sensor data to PC via serial and visualise the data in a software called Processing.

Now make your own temperature sensor by Arduino and LM35 Sensor
You require the  following parts:

• 1-ARDUINO BOARD ANY VERSION
  
• 2-LM35 TEMPERATURE SENSOR
  
• 3-USB CABLE
  
• 4-COMPUTER WITH ARDUINO SOFTWARE
  

Few points on LM35

• Calibrated Directly in Celsius (Centigrade)
• Linear + 10-mV/°C Scale Factor
• 0.5°C Ensured Accuracy (at 25°C)
• Rated for Full −55°C to 150°C Range
• Suitable for Remote Application

Connecting LM 35 to Arduino (UNO) :

Sending serial data to Processing :

//import Serial communication library
import processing.serial.*;
//init variables
Serial commPort;
float tempC;
float tempF;
int yDist;
float[] tempHistory = new float[100];
void setup()
{
 //setup fonts for use throughout the application
//set the size of the window
 size(360,320);
//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);
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);
textAlign(LEFT);
 text(str(int(tempC)) + " C", 115, 37);
 tempF = ((tempC*9)/5) + 32;
 text(str(int(tempF)) + " F", 115, 65);
 }
}