Published February 8, 2021 © GPL3+

Temperature Controlled Fan

LM35 Temperature controlled Fan

IntermediateFull instructions provided2,994

Things used in this project

Hardware components

Arduino Nano R3

Solderless Breadboard Full Size

Jumper wires (generic)

DFRobot Gravity: Analog LM35 Temperature Sensor For Arduino

Linear Regulator (7805)

MOSFET Transistor, Switching

Axial Fan, 12 VDC

Buzzer

General Purpose Transistor NPN

Capacitor 100 µF

Capacitor 100 nF

Resistor 1k ohm

Multi-Turn Precision Potentiometer- 10k ohms (25 Turn)

Resistor 100 ohm

9V battery (generic)

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Extraction Tool, 6 Piece Screw Extractor & Screwdriver Set

Soldering Station, 110 V

Story

ABOUT THE PROJECT:

in this project I am going to build a Temperature Controlled Fan using LM35 precision Temperature sensor. we can get the Temperature value on and Fan speed on HD44780(16 * 2) LCD. Let's get started!

NECESSITY OF THE PROJECT:

Almost in summer days sometimes days become extremely hot and sometimes extremely Cold. so we use a Fan Regulator to regulate the speed of Fan according to the environment Temperature i.e. if temperature is High, we rotate the knob of the potentiometer in clockwise direction but anticlockwise in case of low Temperature. But we are living in 2021. This is the time of Microcontrollers( like Arduino development boards). and people like to use an automatic Temperature controlled Fan ( A Fan that rotates according to temperature).So that is why in this project I am going to make a Temperature Controlled Fan. Although in this project I am using a 12V DC Fan in place of 230V/50Hz AC Fan. But I make a promise that I will really make next project on AC Fan.

HARDWARE LIST:

Arduino nano
HD44780 LCD (16 * 2) lcd
LM35 Temperature Sensor
12V CPU Fan
IRLZ44 N-Channel MOSFET
LM7805 Regulator
BC547 Transistor
Buzzer
Bread board
jumper wires
1k Resistors
100UF/25V electrolytic capacitor
1N4007 Diode
10K Potentiometer
12V Battery

ABOUT LM35 SENSOR:

The LM 35 series are precision integrated-circuit Temperature sensor with an output voltage linearly proportional to Centigrade Temperature.This sensor looks like a Transistor because and it is available in TO-92 Package/TO-220 Package/TO-46 metal can package/SO-8 package. but In present I am going to use TO-92 package. The pinout of the IC has been given below-

Features of LM35 Sensor-

Calibrated directly in Celsius
linear +10mV/deg.C scale factor
-55/deg.C to +150/deg.C range
operation Voltage 4 - 30V

for more you can visit

https://www.electroschematics.com/wp-content/uploads/2010/02/LM35-DATASHEET.pdf

LIBRARY FOR LM35 SENSOR:

https://www.arduino.cc/reference/en/libraries/lm35-sensor/

FOLLOW THESE STEPS TO MAKE THE PROJECT:

connect all the necessary parts to one another according to given schematic then check all the connections twice because if the is any error in the connections that you make, your project will not work and the write the codes for the project if you don't know how to do that then you can just copy my code and paste it on your editor and upload, after uploading supply the project with a 12V Lead-Acid Battery

PICTURES OF MY WORK:

PICTURE-1

Picture-2

Picture-3

Picture-4

Picture-5

Picture-6

Picture-7

Picture-8

Picture-9

Video:

Code

LM35 Temperature Fan

// Ramji Patel376 //
// Arduino.cc //

#include <LiquidCrystal.h>
LiquidCrystal lcd(5,6,7,8,9,10);

int tempPin = A4; // the output pin of LM35
int fan = 3; // the pin where fan is
int led = 12; // led pin
int temp;
int tempMin = 30;          // the temperature to start the fan 0%
int tempMax = 60;         // the maximum temperature when fan is at 100%
int fanSpeed;
int fanLCD;
int buzzer = 13;
 
void setup() {
pinMode(fan, OUTPUT);
pinMode(led, OUTPUT);
pinMode(tempPin, INPUT);
lcd.begin(16,2);
Serial.begin(9600);
}
 
void loop()
{
temp = readTemp();            // get the temperature
Serial.print( temp );
if(temp < tempMin)           // if temp is lower than minimum temp
{
fanSpeed = 0;               // fan is not spinning
analogWrite(fan, fanSpeed);
fanLCD=0;
digitalWrite(fan, LOW);
}
if((temp >= tempMin) && (temp <= tempMax))         // if temperature is higher than minimum temp
{
fanSpeed = temp;//map(temp, tempMin, tempMax, 0, 100);       // the actual speed of fan//map(temp, tempMin, tempMax, 32, 255);
fanSpeed=1.5*fanSpeed;
fanLCD = map(temp, tempMin, tempMax, 0, 100);          // speed of fan to display on LCD100
analogWrite(fan, fanSpeed);            // spin the fan at the fanSpeed speed
}
 
if(temp > tempMax)          // if temp is higher than tempMax
{
digitalWrite(led, HIGH);     // turn on led
}
else // else turn of led
{
digitalWrite(led, LOW);
}
lcd.setCursor(0,0);
lcd.print("TEMP: ");
lcd.print(temp);          // display the temperature
lcd.print("C ");
lcd.setCursor(0,1);      // move cursor to next line
lcd.print("FANS: ");
lcd.print(fanLCD);      // display the fan speed
lcd.print("%");

}
 
int readTemp() {
  // get the temperature and convert it to celsius
temp = analogRead(tempPin);
return temp * 0.48828125;
}