Abstract
Health monitoring systems play an important role in the early detection and prevention of medical conditions. This project presents a real-time health monitoring system using the ESP32/Arduino platform, integrating the MAX30105 pulse oximeter sensor and DHT11 temperature sensor. The system is designed to measure vital physiological parameters such as heart rate (HR), blood oxygen saturation level (SpO₂), and body temperature in a non-invasive manner.
The MAX30105 sensor is used to detect heart rate and SpO₂ values by analysing red and infrared light absorption through the fingertip. To improve accuracy and reduce noise, sample averaging techniques are implemented in the software. Finger detection logic ensures that readings are taken only when a finger is properly placed on the sensor. The DHT11 sensor measures body temperature, which is calibrated for reliable output.
All measured parameters are displayed in real time on a 16×2 I2C LCD, and the system classifies the user’s health condition as Normal, Warning, or Critical based on predefined threshold values. Additionally, the readings are sent to the serial monitor for debugging and analysis.
This project demonstrates a low-cost, portable, and user-friendly health monitoring solution suitable for home healthcare, remote patient monitoring, and educational applications. It highlights the effective use of embedded systems and sensors for basic medical parameter monitoring.

Introduction
In recent years, the need for continuous and real-time health monitoring has increased significantly due to rising health issues and lifestyle-related diseases. Regular monitoring of vital health parameters such as heart rate, blood oxygen saturation (SpO₂), and body temperature helps in the early detection of medical conditions and reduces the risk of serious complications. However, frequent hospital visits for basic health checkups are time-consuming and expensive.
Advancements in embedded systems and sensor technology have made it possible to develop compact, low-cost, and portable health monitoring devices. Sensors such as pulse oximeters and temperature sensors can now provide accurate physiological data in real time. When combined with microcontrollers, these sensors enable efficient data processing and display without the need for complex medical equipment.
This project focuses on the design and implementation of a health monitoring system using the MAX30105 pulse oximeter sensor and DHT11 temperature sensor. The MAX30105 sensor measures heart rate and SpO₂ levels using optical sensing techniques, while the DHT11 sensor is used to monitor body temperature. The measured values are displayed on a 16×2 LCD, making the system easy to use and understand for any user.
The system also includes finger detection and signal averaging techniques to improve accuracy and reliability of the readings. Based on the measured parameters, the user’s health condition is categorized as Normal, Warning, or Critical, providing quick and useful feedback. This project demonstrates an effective approach to basic health monitoring using embedded technology and can be further enhanced for advanced medical and IoT-based applications.

Objectives
1. To design a simple health monitoring system.
2. To measure heart rate using the MAX30105 sensor.
3. To measure blood oxygen level (SpO₂).
4. To measure body temperature using the DHT11 sensor.
5. To detect whether a finger is placed on the sensor or not.
6. To display all values on a 16×2 LCD.
7. To show the health condition as Normal, Warning, or Critical.
8. To make the system low cost and easy to use.