Temperature control fan using Arduino uno ||Arduino control fan

Arduino code

#include <DHT.h>

#define DHTPIN 2       // Digital pin connected to the DHT sensor

#define DHTTYPE DHT11  // DHT 11

DHT dht(DHTPIN, DHTTYPE);

// Motor driver connections

#define MOTOR_PIN_1 3  // Motor driver input 1

#define MOTOR_PIN_2 4  // Motor driver input 2

void setup() {

  Serial.begin(9600);

  dht.begin();

  // Motor driver pins setup

  pinMode(MOTOR_PIN_1, OUTPUT);

  pinMode(MOTOR_PIN_2, OUTPUT);

}

void loop() {

  delay(2000);  // Delay between sensor readings

  // Read temperature

  float temperature = dht.readTemperature();

  if (isnan(temperature)) {

    Serial.println("Failed to read temperature from DHT sensor!");

    return;

  }

  Serial.print("Temperature: ");

  Serial.print(temperature);

  Serial.println(" °C");

  // Set fan speed based on temperature

  int speed = temperature * 4; // Speed of motor = temperature in Celsius * 4

Serial.print("Fan speed");

Serial.print(speed);

  if (speed > 255) {

    speed = 255; // Ensure speed does not exceed maximum PWM value

  }

  analogWrite(MOTOR_PIN_1, speed); // Set motor speed using PWM

  if (temperature > 25) {

    // Fan on

    digitalWrite(MOTOR_PIN_2, LOW);

  } else {

    // Fan off

    digitalWrite(MOTOR_PIN_2, HIGH);

  }

}

Connection:

DHT11 Sensor:

VCC -> 5V

GND -> GND

Data -> Pin 2

Motor Driver:

Motor Input 1 (PWM) -> Pin 3

Motor Input 2 -> Pin 4