Arduino thermometer using LM35 temperature for beginners


In the world of electronics, temperature sensors are one of the most commonly used components. They are used in a variety of applications, including home appliances, industrial systems, and scientific instruments. The LM35 temperature sensor is one such device that is frequently used to measure temperature in electronic projects. In this project, we will use an Arduino UNO and an LM35 temperature sensor to build a digital thermometer that displays temperature readings on a 16×2 LCD display.

Hardware Required

You will require the following Hardware Components for making an Arduino thermometer using LM35 temperature.

Components#Buy From Amazon
Arduino UNO1Buy Now
LM35 Temperature Sensor1Buy Now
16×2 LCD Display Module1Buy Now
Potentiometer 10KΩ1Buy Now
Battery 9v1Buy Now
Jumper WiresFewBuy Now
Breadboard1Buy Now

What is LM35 Temperature Sensor?

LM35 is a precision integrated-circuit temperature sensor that can be used to measure temperature with an accuracy of ±0.5°C at room temperature. It is a small and inexpensive device that can be easily interfaced with microcontrollers, such as Arduino, to measure temperature in various applications. The LM35 sensor converts the temperature into an analog voltage output that is proportional to the temperature, with a scale factor of 10mV per degree Celsius. The output voltage of the sensor can be directly read by a microcontroller’s analog input pin, which can then be used to calculate the temperature using a simple mathematical formula. The LM35 is a popular choice for temperature sensing applications due to its accuracy, ease of use, and low cost.


  1. Operating Voltage: 4V to 30V
  2. Temperature range: -55°C to +150°C
  3. Output Voltage: 10mV/°C
  4. Accuracy: ±0.5°C
  5. Quiescent Current: Less than 60uA
  6. Package Type: TO-92


  1. Easy to use
  2. High accuracy
  3. Low power consumption
  4. Linear output
  5. Calibrated in Kelvin
  6. Self-calibrated circuitry



Pin Configuration

Pin NoNameFunction
1VccSupply voltage; 5V (+35V to -2V)
2OutputOutput voltage (+6V to -1V)
3GroundGround (0V)

Circuit Diagram

The following circuit shows you the connection of the Arduino thermometer using LM35 temperature. with Arduino Please make the connection carefully


Working Explanation

The LM35 temperature sensor outputs an analog voltage that is proportional to the temperature it measures. We can use this output to determine the temperature using an Arduino. To do this, we connect the LM35 to the Arduino’s analog input pin and use the ADC (analog-to-digital converter) to read the voltage output. We then convert this value into temperature using a simple mathematical formula.

Once we have the temperature value, we can display it on the LCD display. The LCD display is connected to the Arduino using a parallel connection, and we can use the LiquidCrystal library to control the display.

Installing Arduino IDE Software

First, you will require to Download the updated version of Arduino IDE Software and Install it on your PC or laptop. if you Learn How to install the Arduino step-by-step guide then click on how to install Arduino Button given Blow

Installing Libraries

Now when you are Ready to upload the code, to the Arduino Board you will need first to add the Following Libraries in Arduino, If you Learn How to add the library in the Arduino step-by-step guide click on how to install the library Button given Blow


//For more Projects:


LiquidCrystal lcd(12,11,5,4,3,2);

#define sensor A0

byte degree[8] = 


void setup()



  lcd.createChar(1, degree);


  lcd.print("    Digital    ");


  lcd.print("  Thermometer   ");



  lcd.print(" Circuit Digest  ");




void loop()



     float reading=analogRead(sensor);

     float temperature=reading*(5.0/1023.0)*100;


  /*------Display Result------*/










  1. Home automation systems
  2. Industrial automation systems
  3. Weather monitoring systems
  4. Medical equipment
  5. Food processing and storage
  6. HVAC systems
  7. Agriculture systems
  8. Scientific experiments


The LM35 temperature sensor is a simple and effective device for measuring temperature, and it is widely used in electronic projects. This project demonstrates how to use an LM35 sensor with an Arduino to build a digital thermometer that displays temperature readings on an LCD display. This project can be easily modified to suit different temperature sensing requirements and can be used in a variety of applications, including home automation, industrial automation, and scientific experiments.

See Also

  1. Tune Replay Arduino Project Circuit for Beginners
  2. Dual LED Chaser Arduino Project Circuit for Beginners
  3. Arduino Clap Switch Project Circuit for Beginners

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