LM35 Temperature Sensor with Arduino

The LM35 series are precision integrated-circuit temperature devices with an output voltage linearly proportional to the Centigrade temperature. LM35 is three terminal linear temperature sensor from National semiconductors. It can measure temperature from -55 degree Celsius to +150 degree Celsius. The voltage output of the LM35 increases 10mV per degree Celsius rise in temperature. LM35 can be operated from a 5V supply and the stand by current is less than 60uA. The pin out of LM35 is shown in the figure below.

Features

• Calibrated Directly in Celsius (Centigrade)

• Linear + 10-mV/°C Scale Factor

• 0.5°C Ensured Accuracy (at 25°C)

• Rated for Full −55°C to 150°C Range

• Suitable for Remote Applications

• Low-Cost Due to Wafer-Level Trimming

• Operates from 4 V to 30 V

• Less than 60-μA Current Drain

• Low Self-Heating, 0.08°C in Still Air

• Non-Linearity Only ±¼°C Typical

• Low-Impedance Output, 0.1 Ω for 1-mA Load

PinOuts Of LM35 is Shown in image.

 

Components :

• Arduino
• BreadBoard
• LM35 Temperature Sensor
• Some connecting wire

 

Connections:

 

LM-35  has three pins:

• pin 1 is +Vcc
• pin 2 is Output
• pin 3 is Ground

As it is a analog temperature sensor so the output pin of the LM35 will be connected to the Analog  pin of Arduino and other  pins to the 5V & GND pin.

 

Example Code:

const int sensor=A1;
float cel;
float fer;
float kel;

void setup() {
    pinMode(sensor,INPUT);
    Serial.begin(9600);
}
void loop() {
    float value = analogRead(sensor);
    
    cel = value*0.48;
    fer = (cel*1.8)+32;
    kel = cel+273;
    
    Serial.print(cel);
    Serial.println(" *C");

    Serial.print(fer); 
    Serial.println(" *F");

    Serial.print(cel); 
    Serial.println(" *K");
    delay(1000);
}

 

 

NOW SEE THE SERIAL MONITOR IN THE ARDUINO SOFTWERE ,
ITS DONE.