Arduino LM35 Temperature Example

lm35_example.ino

/** 
 * GLOBAL CONFIGURATION VARIABLES
 */
int LM35PIN = 0;

void setup() {
  Serial.begin(9600);
}

void loop() {
  print3Temperatures(LM35PIN);
  delay(1000);
}

/** 
 * Read an LM35 temperature sensor and print the ambient
 * temperature.  Temperatures are measured in Celcius, Farenheit, 
 * and Kelvin.
 * \param pin  the analog pin leading to the LM35 Vout
 */
void print3Temperatures(int pin) {
  Serial.print("Temp: ");
  Serial.print(readTemperatureC(pin));
  Serial.print("*C, ");
  Serial.print(readTemperatureF(pin));
  Serial.print("*F, ");
  Serial.print(readTemperatureK(pin));
  Serial.println("*K");
}

/** 
 * Read an LM35 temperature sensor and print the ambient
 * temperature.  Temperatures are measured in Celcius.
 * \param pin  the analog pin leading to the LM35 Vout
 * \return float the temperature measured in Celcius
 */
float readTemperatureC(int pin) {
  return float(analogRead(pin)) / 1023 * 500;
}

/** 
 * Read an LM35 temperature sensor and print the ambient
 * temperature.  Temperatures are measured in Farenheit.
 * \param pin  the analog pin leading to the LM35 Vout
 * \return float the temperature measured in Farenheit
 */
float readTemperatureF(int pin) {
  return readTemperatureC(pin) * 9.0/5.0 + 32;
}


/** 
 * Read an LM35 temperature sensor and print the ambient
 * temperature.  Temperatures are measured in Kelvin.
 * \param pin  the analog pin leading to the LM35 Vout
 * \return float the temperature measured in Kelvin
 */
float readTemperatureK(int pin) {
  return readTemperatureC(pin) + 273.15;
}