Pulseoxy : Creating an IoT-based pulse oximeter using the Seeed Studio XIAO ESP32C3, MAX30102, and an OLED display for measuring heart rate and SPO2 is an fascinating project.

Built a smart pulse oximeter which measure's the heart rate and spo2 using MAX30102 sensor and Seeed Studio XIAO ESP32C3

What is Seeed Studio XIAO ESP32C3

For Internet of Things projects, Seeed Studio XIAO-ESP32C3 is a small development board. The Espressif ESP32-C3 chip powers it and provides Bluetooth and WiFi connectivity. With its robust floating-point unit and 32-bit RISC-V CPU, the ESP32-C3 offers effective arithmetic processing. The board ensures good radio frequency performance with IEEE 802.11 b/g/n WiFi and Bluetooth 5 (LE) compatibility.

For increased wireless signal strength, the XIAO-ESP32C3 has an external antenna and a compact, single-sided design. It has eleven digital I/O pins for PWM applications and four analog I/O pins for ADC. With its several interfaces (UART, I2C, and SPI), the board can be used for a wide range of applications. For simple programming and debugging, it also includes a reset button and a bootloader mode button.

Features of Seeed Studio XIAO ESP32C3

Features
Strong CPU: ESP32-C3, a 32-bit RISC-V single-core processor with a maximum frequency of 160 MHz
Entire wireless subsystem: Supports Station mode, SoftAP mode, SoftAP + Station mode, and promiscuous mode; complies with IEEE 802.11b/g/n protocol.
Subsystem for Bluetooth LE: supports Bluetooth mesh and Bluetooth 5 functionalities.
Extremely Low Power: Power usage during deep sleep is roughly 43μA.
Improved radio frequency performance: includes an external radio antenna
Chip for charging batteries: facilitates the charge and discharge control of lithium batteries
Rich on-chip resources: 4MB of on-board flash memory and 400KB of SRAM
incredibly tiny size: The size of a thumb (20 x 17.5 mm) The classic form-factor of the XIAO series is ideal for wearables and small projects.Features

Strong CPU: ESP32-C3, a 32-bit RISC-V single-core processor with a maximum frequency of 160 MHz
Entire wireless subsystem: meets the IEEE 802.11b/g/n protocol requirements.

Bluetooth LE subsystem: Facilitates Bluetooth mesh and Bluetooth 5 capabilities

Ultra-Low Power: The power used for deep sleep is approximately 43μA.

Improved radio frequency performance: includes an external radio antenna
Chip for charging batteries: facilitates the charge and discharge control of lithium batteries

Rich on-chip resources: 4MB of on-board flash memory and 400KB of SRAM
incredibly tiny size: The size of a thumb (20 x 17.5 mm) The classic form-factor of the XIAO series is ideal for wearables and small projects.

Hardware Requirement  

• Seeed Studio XIAO ESP32C3
• MAX30102 Heart Rate and Pulse Oximeter Sensor
• 0.91 INCH OLED Display
• Jumper wires
• Breadboard
• 3D printed case
• Type C-Cable

Software requirement 

• Arduino IDE 
• Arduino cloud 
• Arduino cloud Web 
• Arduino IOT Remote App 
• Arduino create agent for cloud

Circuit Diagram 

Interface the components as per circuit diagram 

Adding Compatible Board and Libraries 

Files-> Preferences->ADD below URLs in Additional bord manager ->click OK 

http://arduino.esp8266.com/stable/package_esp8266com_index.json 

https://files.seeedstudio.com/arduino/package_seeeduino_boards_index.json 

https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json 

Arduino cloud interfacing

Follow the same procedure according to cloud irrigation blog

Link- https://robu.in/how-to-make-projectusing-arduino-nano-esp-32-arduino-cloud/

Create Thing

Configure network

Create a dashboard

Link variable 

Open Sketch in full Editor  

just Create float variable Heart rate and SPO2

Edit the code according to variables

Arduino Create Agent

Select the proper  Board and port

Download Sketch from Arduino cloud sketch

Add network credential properly with device secret key.

(NOTE: Don’t forget to pause Arduino create agent else IDE can throw ERROR) 

Libraries installation 

Make sure these libraries are installed OakOLED, DFRobot_MAX30102, Adafruit_GFX, Adafruit_SSD1306 

If not installed them or add them from library manager 

Code 

#include "arduino_secrets.h"
#include "thingProperties.h"
#include <Wire.h>
#include <OakOLED.h>
#include <DFRobot_MAX30102.h>
#include "Adafruit_GFX.h" 
#include <Adafruit_SSD1306.h>

OakOLED oled;
DFRobot_MAX30102 particleSensor;

void setup() {
  Serial.begin(9600);
  delay(1500);

  initProperties();
  ArduinoCloud.begin(ArduinoIoTPreferredConnection);
  setDebugMessageLevel(2);
  ArduinoCloud.printDebugInfo();

  oled.begin();

  while (!particleSensor.begin()) {
    Serial.println("MAX30102 was not found");
    delay(1000);
  }

  particleSensor.sensorConfiguration(50, SAMPLEAVG_4, MODE_MULTILED, SAMPLERATE_100, PULSEWIDTH_411, ADCRANGE_16384);
}

void loop() {
  ArduinoCloud.update();

  int32_t SPO2;
  int8_t SPO2Valid;
  int32_t heartRate;
  int8_t heartRateValid;

  Serial.println(F("Wait about four seconds"));

  particleSensor.heartrateAndOxygenSaturation(&SPO2, &SPO2Valid, &heartRate, &heartRateValid);

  Serial.print(F("Heart Rate: "));
  Serial.print(heartRate, DEC);
  Serial.print(F(", Valid: "));
  Serial.print(heartRateValid, DEC);
  Serial.print(F("; SPO2: "));
  Serial.print(SPO2, DEC);
  Serial.print(F(", Valid: "));
  Serial.println(SPO2Valid, DEC);

  // Display results on OLED
  oled.clearDisplay();
  oled.setTextSize(2);
  oled.setTextColor(SSD1306_WHITE);
  oled.setCursor(0, 0);
  oled.print(F("HR: "));
  oled.print(heartRate);
  oled.setCursor(0, 40);
  oled.print(F("SPO2: "));
  oled.print(SPO2);
  oled.display();

  // Update Arduino IoT Cloud variables
  hR = heartRate;
  sPO2 = SPO2;

  delay(2000); // Adjust the delay as needed
}

Debugging and Uploading code

• Connect the circuit on breadboard as per circuit diagram. 
• Verify and upload the above code into controller board. 
• Make sure your Wi-Fi is on and proper credential is provided in the code. 
• Check if Seeed Studio  board Is connected to Wi-Fi/hotspot 
• If connections and code are proper  Pulse sensor will turn On with OLED display and after placing finger on sensor it will start showing Heart rate and oxygen. 
• Just know that board is generic so read can some time will not piracies if you need precise reading you can you more precise sensor like DF robot max30102,sparkfumax30102. 

Breadboard test connections 

Connections are made according to circuit diagram  

• Make the connection on breadboard as per circuit diagram for testing and connect SEEED studio XIAO ESP32 C3 board with you PC or laptop 
• Upload the basic Example code for OLED display to check the interfacing of OLED display with board 

How to simply 3D print 

• Visit 3D print we site-

https://robu.in/product/3d-printing-service/?utm_source=website&utm_medium=header&utm_campaign=3d-printing-service&utm_id=free_promotion 

• Download STL files from Given link
• TOP-  https://robu.in/wp-content/uploads/2023/12/TOP.stl
• PANEL- https://robu.in/wp-content/uploads/2023/12/panel.stl
• BOTTTOM- https://robu.in/wp-content/uploads/2023/12/bottom.stl
• HINGE- https://robu.in/wp-content/uploads/2023/12/hinge.stl
• Click on Upload Model->Select proper STL file from device–>open it 

Select the Material ->PLA and color>orange ->NEXT

Select printer-> 0.2 mm Standard Quality->NEXT 

Select in Fill->20%->NEXT 

Finalize printing Cost will show -> Select Quantity -> Add to cart   

Follow the same process for other STL files 

View cart->Apply coupon if you have->verify the material, cost and quantity->Proceed to checkout->make the payment 

Hardware interfacing  and final test 

 circuit is fitted in 3d printed case

Place all the components in 3D case, connect them according to circuit diagram with wires 

if you need portable device add switch and battery we have added switch and battery in this pulseoxy

Close the 3D case and Switch on the oximeter

Final working of project 

we have switched ON the device and placed finger in pulseoxy the sensor read the data and transfer it to controller ,controller process it and display it on OLED display which is connected to controller.

controller connects to Wi-Fi and sends data to Arduino cloud and Arduino cloud update it on dashboard. 

Conclusion 

In this way we have completed the Pulseoxy project using SEEED STUDIO XIAO ESP32-C3,MAX30102 and OLED display . Pulseoxy measures and shows Heart rate and SPO2 on OLED display it Automatically connects to your Wi-Fi and shows you real-time Heart rate and SPO2 on Arduino Cloud dashboard As well as on IOT Remote APP.

Watch full tutorial on YouTube :- https://youtu.be/KG3ZActfjWs