Note: this module by default only with 3.3 V level MCU communications, because it defaults to using IIC pin pull up the resistance of 4.7 K to 1.8 V, so there is no communication with the Arduino by default, if you want to commune with the Arduino and need two 4.7 K of the IIC pin pull-up resistor connected to the VIN pin, these contents will be introduced in the back of the chapter.

Functional assignments

Before starting this project, I thought about some simple features:

•  Heart rate data and blood oxygen data were collected

•  Heart rate and blood oxygen data are displayed through an LCD screen

These are the only two features, but if we want to implement it, we need to do more thinking:

•  What master MCU is used?

•  What kind of LCD display?

As we mentioned earlier, we use Arduino for the MCU, but this is an LCD Arduino project, so we need to choose the appropriate LCD display module. I plan to use the LCD display screen with a serial port. I have a STONE STVI070WT-01 displayer here, but if Arduino needs to communicate with it, MAX3232 is needed to do the level conversion.

Then the basic electronic materials are determined as follows:

1. Arduino Mini Pro development board

2. MAX30100 heart rate and blood oxygen sensor module

3. STONE STVI070WT-01 LCD serial port display module

4. MAX3232 module

Hardware Introduction

MAX30100

The MAX30100 is an integrated pulse oximetry and heart rate monitor sensor solution. It combines two LEDs, a photodetector, optimized optics, and low-noise analog signal processing to detect pulse oximetry and heart-rate signals. The MAX30100 operates from 1.8V and 3.3V power supplies and can be powered down through software with negligible standby current, permitting the power supply to remain connected at all times.

Applications

● Wearable Devices

● Fitness Assistant Devices

● Medical Monitoring Devices

Benefits and Features

1、Complete Pulse Oximeter and Heart-Rate SensorSolution Simplifies Design

•  Integrated LEDs, Photo Sensor, and high-Performance Analog Front -End

•  Tiny 5.6mm x 2.8mm x 1.2mm 14-Pin OpticallyEnhanced System-in-Package

2、Ultra-Low-Power Operation Increases Battery Life for wearable Devices

•  Programmable Sample Rate and LED Current for Power Savings

•  Ultra-Low Shutdown Current (0.7µA, type)

3、Advanced Functionality Improves Measurement Performance

•  High SNR Provides Robust Motion Artifact Resilience

•  Integrated Ambient Light Cancellation

•  High Sample Rate Capability

•  Fast Data Output Capability

Detection Principle

Just press your finger against the sensor to estimate pulse oxygen saturation (SpO2) and pulse (equivalent to heartbeat).

The pulse oximeter (oximeter) is a mini-spectrometer that USES the principles of different red cell absorption spectra to analyze the oxygen saturation of the blood. This real-time and rapid measurement method is also widely used in many clinical references.

I will not introduce the MAX30100 too much, because these materials are available on the Internet. Interested friends can look up the information of this heart rate test module on the Internet, and have a deeper understanding of its detection principle.

Introduction to the STVI070WT-01 displayer

In this project, I will use the STONE STVI070WT-01 to display the heart rate and blood oxygen data.

The driver chip has been integrated inside the display screen, and there is software for users to use. Users only need to add buttons, text boxes, and other logic through the designed UI pictures, and then generate configuration files and download them into the display screen to run.

The...