const int sensorPin = A0; const int outputPin = 9; const float threshold = 75.0; // Single threshold in degrees Celsius void setup() { pinMode(outputPin, OUTPUT); digitalWrite(outputPin, LOW); Serial.begin(9600); } void loop() { int sensorValue = analogRead(sensorPin); float temperature = (sensorValue * 5.0 / 1023.0) * 100.0; Serial.print("Temperature: "); Serial.println(temperature); if (temperature >= threshold) { digitalWrite(outputPin, HIGH); // Turn on fan/LED } else { digitalWrite(outputPin, LOW); // Turn off fan/LED } delay(500); }