Heart Rate Monitor

Introduction

The project aims to design a wearable device for heart rate monitoring. The watch continuously records the user’s heartbeats and displays the data, measured in beats per minute (BPM), on a mobile application.

Project Overview

Objectives

The primary objective of this project is to develop a wearable heart rate monitor that continuously records the user’s heartbeats and displays the data in beats per minute (BPM) on a mobile application. Additional goals include ensuring the device is compact, user-friendly, and capable of stable data transmission.

Scope

This project focuses on creating a prototype that demonstrates the core functionality of heart rate monitoring and data transmission via Bluetooth Low Energy (BLE).

Hardware Selection

For this project, the following hardware components have been selected:

Microcontroller: Xiao ESP32-C3

The Xiao ESP32-C3 is chosen for its compact size and built-in Bluetooth Low Energy (BLE) functionality, which is essential for efficient data transmission. Key advantages include:

Compact Size: The small form factor allows for easy integration into wearable applications, ensuring a sleek design suitable for wrist-worn devices.
Performance: With a powerful processor, the ESP32-C3 can efficiently handle data collection and processing tasks, ensuring quick response times and accurate measurements.
Integrated Battery Management: The device features pads for battery connection and includes charging capabilities, facilitating convenient power management.

PPG Sensor: MAX30100

The MAX30100 has been selected for its availability and advantages over other sensors. A comparison with other options is provided in the table below:

Feature	MAX30100	MAX86171	MAX86150	MAX30102	AFE4404
Availability	Readily available	Limited availability	Limited availability	Readily available	Readily available
Cost	Cost-effective	Higher cost	Moderate cost	Moderate cost	Moderate cost
Size	Compact	Compact	Compact	Compact	Larger size
Simplicity	Easy to implement	More complex	Moderate complexity	Easy to implement	Moderate complexity
Accuracy	Sufficient for basic use	High accuracy	High accuracy	Good accuracy	High accuracy
Special Features	Basic heart rate sensing	Advanced features	Advanced features	Good features	Specialized features

Advantages of MAX30100:
- Cost-Effectiveness: Often more affordable than competitors, making it ideal for prototyping.
- Compact Design: Facilitates easy integration into wearable devices.
- Simplicity: Known for its straightforward setup and operation.
Disadvantages:
- Limited Features: Lacks advanced capabilities present in sensors like the MAX86171 and MAX86150.
- Accuracy: May not provide the same level of accuracy as higher-end models in clinical applications.