The LM35 temperature sensor provides a voltage output linearly proportional to temperature in degrees Celsius. It has a measurement range of -55°C to 150°C and outputs 10mV for every 1°C change in temperature. The Arduino code samples the voltage from the LM35 using analogRead(), converts it to millivolts and degrees Celsius, and prints the temperature to the serial monitor every second.

1. LM 35
TEMPERATURE SENSOR

2. Pin configuration

3. •LM35 is a basic temperature
sensor that can be used for
experimental purpose .
•It give the readings in centigrade
since its output voltage is linearly
proportional to temperature.
•For 10mv there will be 1 degree
change in temperature.

4. Principle of working
• A temperature sensor measures the
hotness or coolness of an object.
• The sensor's working base is the voltage
that's read across the diode.
• The temperature rises whenever the
voltage increases.
• The operating temperature range is from -
55°C to 150°C.

5. Connecting to arduino

6. code
int val;
int tempPin = 1;
void setup()
{
Serial.begin(9600);
}
void loop()
{
val = analogRead(tempPin);
float mv = ( val/1024.0)*5000;
float cel = mv/10;
Serial.print("TEMPRATURE = ");
Serial.print(cel);
Serial.print("*C");
Serial.println();
delay(1000);
}

7. • 10 bit resolution=>2^10 divisions
5000mv=1024steps
?(x mv)=reading
x mv=5000*reading/1024
10mv=1 degree C change in temp
Temp=x mv/10

9. Serial monitor output

10. Queries?