Introduction

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.

You can download the datasheet from below file.

lm35.pdf
Download

Step 1: Hardware Required and Circuit Diagram

Arduino Board (Any) Buy it from Flipkart
LM35 Sensor Buy it from Flipkart
BreadBoard

Connect the Circuit as shown in image and upload the following code.

Step 2: Programming the Arduino

Download the code here

/*Code Designed by Sujay in SA Lab*/
const int sensor=A5; // Assigning analog pin A5 to variable 'sensor'
float tempc; //variable to store temperature in degree Celsius
float tempf; //variable to store temperature in Fahreinheit
float vout; //temporary variable to hold sensor reading
void setup() {
pinMode(sensor,INPUT); // Configuring sensor pin as input
Serial.begin(9600);
}
void loop() {
vout=analogRead(sensor);
vout=(vout*500)/1023;
tempc=vout; // Storing value in Degree Celsius
tempf=(vout*1.8)+32; // Converting to Fahrenheit
Serial.print("in DegreeC=");
Serial.print("\t");
Serial.print(tempc);
Serial.print(" ");
Serial.print("in Fahrenheit=");
Serial.print("\t");
Serial.print(tempf);
Serial.println();
delay(500); //Delay of 1 second for ease of viewing
}

Step 3: Output Result

See the result on Serial Monitor....

First of all, I would like to thank you for reading this guide ! I hope it helps you. If You have any queries I am happy to help you.....

Drop a Comment. Your feedback is valuable for me.

Introduction: Arduino Temperature Sensor Using LM35

Attachments

Step 1: Hardware Required and Circuit Diagram

Step 2: Programming the Arduino

Step 3: Output Result