#define temp A3
void setup(){
  pinMode(temp, INPUT);
  Serial.begin(9600);
}
float pre_temp = 0;

void loop() {
  float temperature = 0;
  temperature = (analogRead(temp) * 0.48828125) - 49.95;

  if (pre_temp!=temperature) {
    Serial.print("Temperature: ");
    Serial.print(temperature);
    Serial.println(" C");
    pre_temp= temperature;
  }
  delay(1000);
}