Introduction: Arduino Temperature Sensor (LM35)

In this project I will show you how to measure Temperature using LM35 and Arduino interface . Let's get started!

Step 1: 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.

• 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.


Step 2: Order Your Components!

Step 3: Do the Wiring!

You may use the below schematic for making the connections to the Arduino board


Vcc - 5V

Gnd - Gnd

Vout - A3

Step 4: Upload Code!

To get it work you have to use code above. Upload it to your Arduino using the integrated development environment, for short IDE, which you can download from Arduino's official page and you are done !!

You may use the below link to download arduino software: Click Here

After opening the file compile the code and upload into your Arduino board

note: Make sure that board is selected as Arduino UNO

Open the serial monitor you should see both fahrenheit and celsius.