PROJECT REPORT DEPT. OF EEE. Project Title: DIGITAL THERMOMETER. Date of performance: Submission date: Group Leader: Md. Abdullah Kawser.

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1 DEPT. OF EEE PROJECT REPORT Project Title: DIGITAL THERMOMETER Date of performance: Submission date: Group Leader: Md. Abdullah Kawser Sec : B-2/2 Members ID:

2 DIGITAL THERMOMETER There was once a time when taking someone s temperature involved warming up a glass tube which contained Mercury and then placing it carefully under the tongue for several minutes until the Mercury rose to the indicated temperature number. The number was given in Celsius however and was rather complicated to read not to mention the amount of time in which it took not only for the preparation of the thermometer but also the total process all together was ridiculous. It was not until many years later that people discovered the dangers in the substance known as Mercury.Just one small crack in the glasstube could send someone into a fatal attack of the blood stream. After this huge discovery, came the invention of the safer, easier to use digital thermometer. The battery powered digital thermometer is not only easier to use but, it also does not have a single drop of mercury in it so it is safe to use. It works by electronically taking the persons temperature through a highly sensitive board of circuits in the tip which detect heat when in contact with it. The temperature is then displayed digitally on a small LCD screen so that it is easy to read. Unlike with the old mercury glass tube though, the digital thermometer is available in many types from baby pacifiers to ear thermometers and even medical grade forehead scanners that work by infrared. These thermometers were a huge step for technology and the world too. EQUIPMENTS: 1. Arduino UNO-R3; 2. 16*2 LCD DISPLAY ; 3. LM-35; 4. 10K POTENTIOMETER ;

3 5. JUMPER WIRES ; 6. BREADBOARD ; 7. Green, Red, Blue LED as indicator ; WORKING PRINCIPLE: This project is about to measure the temperature in both Celsius and farenhite. For the temperature measurement,we have used a LM-35 sensor which can sense the temperature and give the output as10mv/c. The millivolts then converted into Celsius and celsius is converted into farenhite. We have used a LCD display to observe the temperature. The LM-35 would give an analog output connected at ARDUINO analog(a0) pin. We have used a 10k potentiometer into LCD pin 3. There are 3 levels of temperature measured in the project- Low, Moderate & High When the temperature level is high the red one s starts to blink, in moderate the blue and in low temperature the green blink. That s the Working principle of digital thermometer. CODING: #include <LiquidCrystal.h> LiquidCrystal lcd(12,11,5,4,3,2); //Digital pins to which you connect the LCD const int inpin = 0; // A0 is where you connect the sensor void setup() { lcd.begin(16,2); pinmode(13, OUTPUT);

4 pinmode(9, OUTPUT); pinmode(6, OUTPUT); } void loop() { int value = analogread(inpin); // read the value from the sensor lcd.setcursor(0,1); float millivolts = (value / ) * 5000; float celsius = millivolts / 10; lcd.clear(); lcd.setcursor(0,0); lcd.print(celsius); lcd.print("c"); lcd.setcursor(0,1); lcd.print((celsius * 9)/5 + 32); //turning the celsius into fahrehait lcd.print("f"); if (celsius >25 && celsius< 40) { digitalwrite(7, HIGH); lcd.setcursor(15,0); lcd.print("e");

5 lcd.setcursor(14,0); lcd.print("t"); lcd.setcursor(13,0); lcd.print("a"); lcd.setcursor(12,0); lcd.print("r"); lcd.setcursor(11,0); lcd.print("e"); lcd.setcursor(10,0); lcd.print("d"); lcd.setcursor(9,0); lcd.print("o"); lcd.setcursor(8,0); lcd.print("m"); } else {digitalwrite(7, LOW);}

6 if (celsius <25) { digitalwrite(9, HIGH); lcd.setcursor(15,0); lcd.print("w"); lcd.setcursor(14,0); lcd.print("o"); lcd.setcursor(13,0); lcd.print("l"); } else { digitalwrite(9, LOW);} if( celsius>40 && celsius<100) { digitalwrite(13, HIGH); lcd.setcursor(12,0); lcd.print("h"); lcd.setcursor(13,0);

7 lcd.print("i"); lcd.setcursor(14,0); lcd.print("g"); lcd.setcursor(15,0); lcd.print("h");} else{ digitalwrite(13,low); delay(1000);} delay(500);} ADVANTAGES OF DIGITAL THERMOMETER: APPLICATIONS:

8 Reference : Arduino-UNO/

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