Circuit Documentation

Summary

This circuit is designed to monitor environmental sound levels and heart rate, and to send GPS location data via GSM when certain thresholds are exceeded. It utilizes an Arduino Uno R3 as the central microcontroller to interface with a sound level sensor (LM393), a heart pulse sensor, a Neo 6M GPS module, a Sim800l GSM module, and a buzzer for alerts. The Arduino Uno R3 is programmed to read the analog values from the sensors, compare them against predefined thresholds, and trigger the buzzer if the conditions are met. Additionally, it sends the GPS location through the GSM module as an SMS message in case of an alert.

Component List

Arduino Uno R3

• Microcontroller board based on the ATmega328P
• Features digital I/O pins, analog input pins, and various power options

LM393

• Dual differential comparator that provides a digital signal representing sound levels

Neo 6M GPS Module

• Satellite navigation module capable of providing geographic coordinates

Potentiometer

• Variable resistor used to adjust a voltage level

Heart Pulse Sensor

• Optical heart rate sensor designed for measuring pulse rates

Sim800l

• GSM/GPRS module for cellular communication, capable of sending SMS and making calls

Buzzer

• An electromechanical component that emits sound when an electrical signal is applied

Wiring Details

Arduino Uno R3

• 5V connected to VCC of Sim800l, Heart Pulse Sensor, LM393, and Neo 6M GPS Module
• GND connected to GND of Sim800l, Heart Pulse Sensor, LM393, Neo 6M GPS Module, and Buzzer
• A0 connected to A0 of LM393 (Sound Level)
• A1 connected to SIGNAL of Heart Pulse Sensor
• D7 connected to PIN of Buzzer
• D8 connected to TXD of Sim800l (GSM Module)
• D9 connected to RXD of Sim800l (GSM Module)
• D10 connected to RX of Neo 6M GPS Module
• D11 connected to TX of Neo 6M GPS Module

LM393

• A0 connected to A0 of Arduino Uno R3
• D0 not connected
• GND connected to GND of Arduino Uno R3
• VCC connected to 5V of Arduino Uno R3

Neo 6M GPS Module

• GND connected to GND of Arduino Uno R3
• TX connected to D11 of Arduino Uno R3
• RX connected to D10 of Arduino Uno R3
• VCC connected to 5V of Arduino Uno R3

Potentiometer

• Not connected in this circuit

Heart Pulse Sensor

• GND connected to GND of Arduino Uno R3
• VCC connected to 5V of Arduino Uno R3
• SIGNAL connected to A1 of Arduino Uno R3

Sim800l

• NET not connected
• RST not connected
• VCC connected to 5V of Arduino Uno R3
• RXD connected to D9 of Arduino Uno R3
• TXD connected to D8 of Arduino Uno R3
• GND connected to GND of Arduino Uno R3

Buzzer

• PIN connected to D7 of Arduino Uno R3
• GND connected to GND of Arduino Uno R3

Documented Code

#include <SoftwareSerial.h>

const int soundPin = A0;  // LM393 Analog Output
const int heartRatePin = A1;
const int buzzerPin = 7;

const int gpsRxPin = 10;
const int gpsTxPin = 11;
const int gsmRxPin = 8;
const int gsmTxPin = 9;

SoftwareSerial gpsSerial(gpsRxPin, gpsTxPin); // RX, TX for GPS
SoftwareSerial gsmSerial(gsmRxPin, gsmTxPin); // RX, TX for GSM

const int soundThreshold = 500;
const int heartRateThreshold = 600;

void setup() {
  pinMode(soundPin, INPUT);
  pinMode(heartRatePin, INPUT);
  pinMode(buzzerPin, OUTPUT);

  Serial.begin(9600);
  gpsSerial.begin(9600);  // GPS baud rate
  gsmSerial.begin(9600);  // GSM baud rate

  Serial.println("System Initialized");
}

void loop() {
  int soundLevel = analogRead(soundPin);
  int heartRate = analogRead(heartRatePin);

  Serial.print("Sound Level: ");
  Serial.println(soundLevel);
  Serial.print("Heart Rate: ");
  Serial.println(heartRate);

  if (soundLevel > soundThreshold || heartRate > heartRateThreshold) {
    digitalWrite(buzzerPin, HIGH);  // Activate buzzer
    Serial.println("Danger detected! Buzzer ON.");
    sendGPSLocation();
  } else {
    digitalWrite(buzzerPin, LOW);   // Deactivate buzzer
    Serial.println("Safe. Buzzer OFF.");
  }

  delay(1000);
}

void sendGPSLocation() {
  gsmSerial.println("AT"); // Check connection
  delay(1000);
  gsmSerial.println("AT+CMGF=1"); // Set SMS mode to text
  delay(1000);
  gsmSerial.println("AT+CMGS=\"+1234567890\""); // Recipient phone number
  delay(1000);

  gsmSerial.println("Danger detected. GPS Location:");
  
  while (gpsSerial.available()) {
    char c = gpsSerial.read();
    gsmSerial.write(c); // Send GPS data to GSM
  }

  delay(1000);
  gsmSerial.println((char)26); // End SMS with Ctrl+Z

  Serial.println("SMS sent with GPS location.");
}

This code is designed to run on the Arduino Uno R3. It initializes the serial communications for both the GPS and GSM modules, reads the sound level and heart rate, and triggers the buzzer if the readings exceed the set thresholds. It also contains a function sendGPSLocation to send the current GPS location via SMS using the GSM module.