Circuit Documentation

Summary

This circuit is designed to monitor various health parameters and environmental conditions. It includes an Arduino Mega 2560 as the main microcontroller, interfaced with a variety of sensors and modules such as the ESP8266 NodeMCU for WiFi connectivity, a GPS module for location tracking, a GSM module for communication, and various sensors for measuring temperature, heart rate, and blood oxygen levels. The circuit also features an OLED display for data visualization, a DFPlayer Mini for audio output, and a panic/emergency button.

Component List

Microcontrollers

• ESP8266 NodeMCU: A WiFi module that allows the circuit to connect to the internet.
• Arduino Mega 2560: The primary microcontroller used for processing and controlling the various components in the circuit.

Sensors and Modules

• 0.96" OLED: A small display for showing information and readings from the sensors.
• Sim800l: A GSM/GPRS module for cellular communication.
• MAX30102: A pulse oximetry and heart-rate monitor sensor.
• DS18B20 Temperature Sensor: A digital temperature sensor for measuring environmental temperature.
• Green Button: A push button that can be used as an emergency alert trigger.
• MPU-6050: A motion tracking device with a 3-axis gyroscope and a 3-axis accelerometer.
• AD8232 Heart Rate Monitor: A single-lead heart rate monitor for measuring electrocardiography (ECG) signals.
• DFPlayer MINI: A small sound module capable of playing back stored sound files.
• Loudspeaker: An audio output device for the DFPlayer Mini.
• GPS NEO 6M: A GPS module for location tracking.

Wiring Details

ESP8266 NodeMCU

• RX: Connected to Arduino Mega 2560 TX1 (D18)
• TX: Connected to Arduino Mega 2560 RX1 (D19)
• GND: Common ground with Arduino Mega 2560 and other components
• VIN: Powered by the 3.3V output from Arduino Mega 2560

Arduino Mega 2560

• D18/TX1: Connected to ESP8266 NodeMCU RX
• D19/RX1: Connected to ESP8266 NodeMCU TX
• GND: Common ground with all components
• 3V3: Powers the ESP8266 NodeMCU, MAX30102, and AD8232 HeartRate Monitor
• 5V: Powers the Green Button, DFPlayer MINI, GPS NEO 6M, Sim800l, DS18B20 Temperature Sensor, 0.96" OLED, and MPU-6050
• A0: Connected to AD8232 HeartRate Monitor OUTPUT
• D21/SCL: Connected to MAX30102 SCL, 0.96" OLED SCK, and MPU-6050 SCL
• D20/SDA: Connected to MAX30102 SDA, 0.96" OLED SDA, and MPU-6050 SDA
• D17 PWM/RX2: Connected to Sim800l TXD
• D16 PWM/TX2: Connected to Sim800l RXD
• D15/RX3: Connected to GPS NEO 6M TX
• D14/TX3: Connected to GPS NEO 6M RX
• D2 PWM: Connected to DS18B20 Temperature Sensor OUT
• D4 PWM: Connected to Green Button OUT
• D7 PWM: Connected to AD8232 HeartRate Monitor LO+
• D8 PWM: Connected to AD8232 HeartRate Monitor LO-
• D10 PWM: Connected to DFPlayer MINI RX
• D11 PWM: Connected to DFPlayer MINI TX

0.96" OLED

• GND: Common ground
• VDD: Powered by the 5V output from Arduino Mega 2560
• SCK: Connected to Arduino Mega 2560 SCL (D21)
• SDA: Connected to Arduino Mega 2560 SDA (D20)

Sim800l

• NET: Not connected
• RST: Not connected
• VCC: Powered by the 5V output from Arduino Mega 2560
• RXD: Connected to Arduino Mega 2560 TX2 (D16)
• TXD: Connected to Arduino Mega 2560 RX2 (D17)
• GND: Common ground

MAX30102

• VIN: Powered by the 3.3V output from Arduino Mega 2560
• SDA: Connected to Arduino Mega 2560 SDA (D20)
• SCL: Connected to Arduino Mega 2560 SCL (D21)
• GND: Common ground

DS18B20 Temperature Sensor

• GND: Common ground
• VCC: Powered by the 5V output from Arduino Mega 2560
• OUT: Connected to Arduino Mega 2560 D2 PWM

Green Button

• OUT: Connected to Arduino Mega 2560 D4 PWM
• VCC: Powered by the 5V output from Arduino Mega 2560
• GND: Common ground

MPU-6050

• VCC: Powered by the 5V output from Arduino Mega 2560
• GND: Common ground
• SCL: Connected to Arduino Mega 2560 SCL (D21)
• SDA: Connected to Arduino Mega 2560 SDA (D20)

AD8232 HeartRate Monitor

• GND: Common ground
• 3.3v: Powered by the 3.3V output from Arduino Mega 2560
• OUTPUT: Connected to Arduino Mega 2560 A0
• LO-: Connected to Arduino Mega 2560 D8 PWM
• LO+: Connected to Arduino Mega 2560 D7 PWM

DFPlayer MINI

• VCC: Powered by the 5V output from Arduino Mega 2560
• RX: Connected to Arduino Mega 2560 D10 PWM
• TX: Connected to Arduino Mega 2560 D11 PWM
• SPK1: Connected to Loudspeaker pin1
• SPK2: Connected to Loudspeaker pin2
• GND: Common ground

Loudspeaker

• pin1: Connected to DFPlayer MINI SPK1
• pin2: Connected to DFPlayer MINI SPK2

GPS NEO 6M

• VCC: Powered by the 5V output from Arduino Mega 2560
• RX: Connected to Arduino Mega 2560 TX3 (D14)
• TX: Connected to Arduino Mega 2560 RX3 (D15)
• GND: Common ground

Documented Code

#include <Adafruit_MAX31855.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_MAX30105.h>
#include <DallasTemperature.h>
#include <OneWire.h>
#include <MPU6050.h>
#include <SoftwareSerial.h>
#include <DFRobotDFPlayerMini.h>

// OLED Display
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire);

// MAX30102
Adafruit_MAX30105 max30102;

// DS18B20
OneWire oneWire(2);
DallasTemperature tempSensor(&oneWire);

// MPU6050
MPU6050 mpu;

// GSM Module
SoftwareSerial gsmSerial(12, 13); // GSM TX, RX
#define GUARDIAN_NUMBER "+1234567890"
#define HOSPITAL_NUMBER "+0987654321"

// ECG Sensor
#define ECG_PIN A0
#define LEAD_OFF_PLUS_PIN 7
#define LEAD_OFF_MINUS_PIN 8

// Emergency Button
#define PANIC_BUTTON_PIN 4

// GPS Data
String latitude = "N/A";
String longitude = "N/A";

// DFPlayer Mini
SoftwareSerial dfSerial(10, 11); // DFPlayer RX, TX
DFRobotDFPlayerMini dfPlayer;

void setup() {
  Serial.begin(9600);
  Wire.begin();
  
  // OLED Initialization
  if (!display.begin(SSD1306_I2C_ADDRESS, 0x3C)) {
    Serial.println("OLED initialization failed.");
    for (;;);
  }
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);

  // Initialize MAX30102
  if (!max30102.begin()) {
    Serial.println("MAX30102 not detected.");
    for (;;);
  }

  // Initialize DS18B20
  tempSensor.begin();

  // Initialize MPU6050
  mpu.initialize();

  // Initialize ECG Sensor
  pinMode(LEAD_OFF_PLUS_PIN, INPUT);
  pinMode(LEAD_OFF_MINUS_PIN, INPUT);

  // Initialize Emergency Button
  pinMode(PANIC_BUTTON_PIN, INPUT_PULLUP);

  // Initialize GSM
  gsmSerial.begin(9600);

  // Initialize DFPlayer Mini
  dfSerial.begin(9600);
  if (!dfPlayer.begin(dfSerial)) {
    Serial.println("DFPlayer initialization failed!");
    for (;;);