#include "DHT.h" #include "LiquidCrystal.h" LiquidCrystal lcd(7, 8, 9, 10, 11 ,12); #define DHTPIN 6 #define DHTTYPE DHT22 DHT sensor(DHTPIN, DHTTYPE); int relay_pin = 9; void setup() { lcd.begin(16,2); sensor.begin(); pinMode(relay_pin, OUTPUT); digitalWrite(relay_pin, HIGH); } void loop() { lcd.clear(); float t = sensor.readTemperature(); //reading the temperature from the sensor // Checking if the sensor is sending values or not if (isnan(t)) { lcd.print("Failed"); delay(1000); return; } lcd.setCursor(0,0); lcd.print("Temp: "); lcd.print(t); lcd.print(" C"); if (t > 35){ digitalWrite(relay_pin, LOW); lcd.setCursor(0,1); lcd.print("Fan is ON "); delay(10); } else{ digitalWrite(relay_pin, HIGH); lcd.setCursor(0,1); lcd.print("Fan is OFF "); } delay(2000); }