The project is a self-made heart rate monitor and pulse oximeter such as a MAX30100 pulse oximeter dielectric sensor, NodeMCU ESP8266.
MAX30100 Sensors: It is an integrated pulse oxide saturation and heart rate monitoring sensor module. It combines two LEDs, a photodetector, optimized optical device and low noise analog signal processing to detect pulse oxide saturation and heart rate signals. The MAX30100 is powered from 1.8V and 3.3V, which can be turned off by software, and the standby current is negligible, allowing the power to be always connected.
System Block Diagram:
(MAX30100 block diagram)
Schematic:
Set the blynk android application:
BLYNK is an application running on Android and iOS devices that controls any Internet-based application via smartphones. It allows the IoT application to create a graphical user interface. Here, the BLYNK application will be set to make the NodeMCU ESP8266 monitors BPM and SPO2 through Wi-Fi.
1. So download and install the Blynk application from the Google Play Store. IOS users can download from the App Store. After the installation is complete, open the application and register with the email ID and password.
2. Click "New Project". Set parameters such as the item name, development board, and connection type shown in the figure above. For the MAX30100 ESP8266 project, select the device to NodeMCU, the connection type is Wi-Fi. Then click Create.
3. Click "+" to add a widget. The value of BPM and SPO2 needs to be read. So select a pair of widgets named "ValuedISplay" and "Gauge".
4. After dragging the widget, set its parameters as shown above. Click the value to display and set the pin to "V7" and "V8". Similarly, in the meter settings, the output pin is set to "V7" and "V8".
After successful creation project, return to the settings and click Send Email.
Code: (click to download)
#include
#include "MAX30100_PulseOximeter.h"
#define blynk_print serial
#include
#include
#include
Be
#include "wire.h"
#define reporting_period_ms 1000
// PulseOximeter is the senior interface of the sensor
// it provides:
// * Beat test report
// * heart rate calculation
// * SPO2 (oxidation level) calculation
Be
Char auth [] = "v60fhfjerbzazzmybws2uszs2qvy6sjk";
CHAR SSID [] = "TP-LINK_9950"; // WiFi credentials.
CHAR Pass [] = "8348502146"
Be
// Connection: SCL PIN - D1, SDA PIN - D2, INT PIN - D0
PulseOximeter Pox;
Be
Float BPM, SPO2;
UINT32_T TSLASTREPORT = 0;
Be
// Trigger a callback when the pulse is detected (register below)
Be
Void onbeatdtected ()
{
Serial.Println ("beat!");
}
Be
Void setup ()
{
Serial.begin (115200);
Be
PinMode (16, OUTPUT);
BLYNK.BEGIN (Auth, SSID, PAS);
Be
Serial.Print ("Initializing Pulse OximeTer ..");
// Initialize the PulseOximeter instance
/ / The fault is usually due to improper I2C wiring, the power supply is missing
/ / Or wrong target chip
Be
IF (! Pox.begin ()) {
Serial.Println ("failed");
For (;;);
} Else {
Serial.Println ("Success");
}
// The default current of the IR LED is 50mA, can be changed
// The following rows are removed by canceling. Check the MAX30100_REGISTERS.H for all
// Available options.
// Pox.setirledCurrent (MAX30100_LED_CURR_7_6MA);
/ / Register a callback for the beat test
Pox.setonbeatdtected; onbeatdtected;
Be
}
Be
void loop ()
{
Pox.Update ();
BLYNK.Run ();
Be
BPM = Pox.getHeartrate ();
SPO2 = Pox.getspo2 ();
Be
IF (Millis () - TslastReport > Reporting_Period_MS)
{
Serial.Print ("Heart Rate:");
Serial.Print (bpm);
Serial.Print ("BPM / SPO2:");
Serial.Print (SPO2);
Serial.Println ("%");
Be
BLYNK.VIRTUALWRITE (V7, BPM);
BLYNK.VIRTUALWRITE (V8, SPO2);
Be
TslastReport = Millis ();
}
}
Our other product:
