In our previous blog, we interfaced Pulse-Oximeter (Max30100) Module to NodeMCU. With a little bit of modification that can be upgraded to a full functioning Pulse-Oximeter. We have interfaced 0.96" I2C OLED display before. Today we made a Pulse-Oximeter using that knowledge.
Follow our previous blogs for a better understanding of the scenario.
Pulse Oximeter MAX30100 Interface with NodeMCU
OLED Display Interface with Arduino
Things we need:
- NodeMCU
- Max30100 Module
- 0.96" OLED I2C Display Module
- Female Berg Strip Connector
- Dot Vero Board
- Soldering Kit
- Nut and Bolts 1/8"
- PVC Spacer Tube
Connection Diagram:
Now follow the diagram below to do the connections.
After the connection is done upload the code below.
Source Code:
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| /* | |
| Controller : NodeMCU | |
| Display : 0.96" OLED I2C | |
| Sensor : MAX30100 | |
| */ | |
| #include <Wire.h> | |
| #include <Blynk.h> | |
| #include <ESP8266WiFi.h> | |
| #include <BlynkSimpleEsp8266.h> | |
| #include <Adafruit_GFX.h> | |
| #include <Adafruit_SSD1306.h> | |
| #include <OneWire.h> | |
| #include <DallasTemperature.h> | |
| #include "MAX30100_PulseOximeter.h" | |
| /*-------------------- Timer --------------------*/ | |
| #define REPORTING_PERIOD_MS 1000 | |
| #define REPORTING_PERIOD_MS_1 30000 | |
| uint32_t tsLastReport = 0; | |
| uint32_t tsLastReport1 = 0; | |
| /*-------------------- OLED --------------------*/ | |
| #define OLED_RESET D5 | |
| #define SCREEN_WIDTH 128 | |
| #define SCREEN_HEIGHT 64 | |
| Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET); | |
| /*-------------------- Blynk --------------------*/ | |
| char auth[] = "lfCiyoMVb8455V_-uKbx8HVxiLWRGN1c"; | |
| char ssid[] = "ProjectHub"; | |
| char pass[] = "creativestudio1974"; | |
| /*-------------------- Max30100 --------------------*/ | |
| PulseOximeter pox; | |
| float BPM, SpO2; | |
| /*-------------------- Temp --------------------*/ | |
| #define ONE_WIRE_BUS 2 | |
| OneWire oneWire(ONE_WIRE_BUS); | |
| DallasTemperature sensors(&oneWire); | |
| float TEMP; | |
| int pinValue; | |
| const unsigned char bitmap [] PROGMEM = | |
| { | |
| 0x00, 0x00, 0x00, 0x00, 0x01, 0x80, 0x18, 0x00, 0x0f, 0xe0, 0x7f, 0x00, 0x3f, 0xf9, 0xff, 0xc0, | |
| 0x7f, 0xf9, 0xff, 0xc0, 0x7f, 0xff, 0xff, 0xe0, 0x7f, 0xff, 0xff, 0xe0, 0xff, 0xff, 0xff, 0xf0, | |
| 0xff, 0xf7, 0xff, 0xf0, 0xff, 0xe7, 0xff, 0xf0, 0xff, 0xe7, 0xff, 0xf0, 0x7f, 0xdb, 0xff, 0xe0, | |
| 0x7f, 0x9b, 0xff, 0xe0, 0x00, 0x3b, 0xc0, 0x00, 0x3f, 0xf9, 0x9f, 0xc0, 0x3f, 0xfd, 0xbf, 0xc0, | |
| 0x1f, 0xfd, 0xbf, 0x80, 0x0f, 0xfd, 0x7f, 0x00, 0x07, 0xfe, 0x7e, 0x00, 0x03, 0xfe, 0xfc, 0x00, | |
| 0x01, 0xff, 0xf8, 0x00, 0x00, 0xff, 0xf0, 0x00, 0x00, 0x7f, 0xe0, 0x00, 0x00, 0x3f, 0xc0, 0x00, | |
| 0x00, 0x0f, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 | |
| }; | |
| void onBeatDetected() | |
| { | |
| display.drawBitmap( 100, 20, bitmap, 28, 28, 1); | |
| display.display(); | |
| } | |
| BLYNK_WRITE (V5) | |
| { | |
| pinValue = param.asInt(); | |
| } | |
| void setup() | |
| { | |
| /*-------------------- Display --------------------*/ | |
| if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { | |
| for (;;); | |
| } | |
| display.clearDisplay(); | |
| display.setTextSize(1); | |
| display.setTextColor(WHITE); | |
| display.setCursor(28, 0); | |
| display.println(F("Project Hub")); | |
| display.display(); | |
| /*-------------------- Blynk --------------------*/ | |
| Blynk.begin(auth, ssid, pass); | |
| /*-------------------- Max30100 --------------------*/ | |
| pinMode(16, OUTPUT); //D0 INT Pin | |
| if (!pox.begin()) | |
| { | |
| display.clearDisplay(); | |
| display.println("POX FAILED"); | |
| display.display(); | |
| for (;;); | |
| } | |
| /*-------------------- Temp --------------------*/ | |
| sensors.begin(); | |
| } | |
| void loop() | |
| { | |
| Jump: | |
| display.clearDisplay(); | |
| display.setCursor(28, 0); | |
| display.println(F("Project Hub")); | |
| display.display(); | |
| pox.begin(); | |
| pox.setOnBeatDetectedCallback(onBeatDetected); | |
| pox.setIRLedCurrent(MAX30100_LED_CURR_7_6MA); | |
| while (1) | |
| { | |
| /*-------------------- POX --------------------*/ | |
| pox.update(); | |
| BPM = pox.getHeartRate(); | |
| SpO2 = pox.getSpO2(); | |
| /*-------------------- Blynk --------------------*/ | |
| Blynk.run(); | |
| /*-------------------- Timer1S --------------------*/ | |
| if (millis() - tsLastReport > REPORTING_PERIOD_MS) | |
| { | |
| /*-------------------- Blynk --------------------*/ | |
| Blynk.virtualWrite(V7, BPM); | |
| Blynk.virtualWrite(V8, SpO2); | |
| /*-------------------- OLED --------------------*/ | |
| display.clearDisplay(); | |
| display.setCursor(28, 0); | |
| display.println(F("Project Hub")); | |
| display.print(" HBPM: "); | |
| display.println(pox.getHeartRate()); | |
| display.print(" SpO2: "); | |
| display.println(pox.getSpO2()); | |
| display.print(" Temp: "); | |
| display.println(TEMP); | |
| display.display(); | |
| tsLastReport = millis(); | |
| } | |
| if (pinValue) | |
| { | |
| sensors.requestTemperatures(); | |
| TEMP = sensors.getTempCByIndex(0); | |
| TEMP = DallasTemperature::toFahrenheit(TEMP); | |
| pinValue = 0; | |
| /*-------------------- Blynk --------------------*/ | |
| Blynk.virtualWrite(V6, TEMP); | |
| /*-------------------- OLED --------------------*/ | |
| display.clearDisplay(); | |
| display.setCursor(28, 0); | |
| display.println(F("Project Hub")); | |
| display.println(""); | |
| display.println(""); | |
| display.print(" Temp: "); | |
| display.println(TEMP); | |
| display.display(); | |
| goto Jump; | |
| } | |
| } | |
| } |
Video:
Watch the video for a better understanding.
Reference:
[1] Sarkar, S., Ghosh, A., Chakraborty, M., & Mondal, A. (2024). Design, Hardware Implementation of a Domestic Pulse Oximeter Using IOT for COVID – 19 Patient. International Journal of Microsystems and Iot, 2(1), 469–475. https://doi.org/10.5281/zenodo.10629635
