Digital Thermometer

Integrating LM35, PIR & UV Sensors with Arduino

About the Project

This project involves the design and implementation of a smart digital thermometer using an Arduino Uno. It integrates LM35, PIR, and UV sensors to measure and monitor environmental conditions. The LM35 sensor provides accurate temperature readings. The PIR sensor detects human presence to activate readings, improving energy efficiency. A UV sensor measures ultraviolet light intensity and aids in temperature calibration. Sensor data is processed by the Arduino and displayed in real time on an LCD. The system activates only when motion is detected, conserving power intelligently. It is suitable for health monitoring, smart homes, and environmental sensing. Compact, responsive, and easy to use, the thermometer delivers reliable performance. This integration of multiple sensors enhances its versatility across multiple applications.


  • The LM35 sensor is used for accurate temperature measurement.
  • The PIR sensor detects human presence, enabling automatic activation of temperature readings.
  • UV light sensor is used to measure the intensity of ultraviolet light in the environment, which is then correlated with temperature through a calibration process to estimate and display the ambient temperature.

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Project Report (PDF)

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Source Code

View the complete Arduino code.

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