Real-time Accident Detection System Documentation

Summary

This document provides a detailed overview of a real-time accident detection system. The system uses an ESP32 microcontroller, a GSM800L module, a GPS NEO 6M module, an Adafruit ADXL345 accelerometer, a buzzer, and power sources. The system detects accidents using the accelerometer, triggers a buzzer, and sends an alert message with the GPS location via the GSM module.

Component List

1. ESP32

   • Description: A powerful microcontroller with Wi-Fi and Bluetooth capabilities.
   • Pins: EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, GND, VIN, 3V3, D15, D2, D4, RX2, TX2, D5, D18, D19, D21, RX0, TX0, D22, D23, BOOT

2. GPS NEO 6M

   • Description: A GPS module used for obtaining location data.
   • Pins: VCC, RX, TX, GND

3. Adafruit ADXL345

   • Description: A 3-axis accelerometer used for detecting motion and acceleration.
   • Pins: VIN, 3.3V, GND, CS, INT1, INT2, SDO/ADDR, SDA/SDIO, SCL

4. SIM800L

   • Description: A GSM module used for sending SMS and making calls.
   • Pins: NET, VCC, RST, RXD, TXD, GND, RING, DTR, MIC+, MIC-, SPK+, SPK-

5. Battery 18650

   • Description: A rechargeable lithium-ion battery.
   • Pins: +, -

6. Buzzer

   • Description: An audio signaling device.
   • Pins: +, GND

7. 5V Battery

   • Description: A power source providing 5V.
   • Pins: +, -

Wiring Details

ESP32

• D25: Connected to Buzzer (+)
• D26: Connected to SIM800L (TXD)
• D27: Connected to SIM800L (RXD)
• GND: Connected to Battery 18650 (-), 5V Battery (-), GPS NEO 6M (GND), Buzzer (GND), Adafruit ADXL345 (GND), SIM800L (GND), SIM800L (RST)
• RX2: Connected to GPS NEO 6M (TX)
• TX2: Connected to GPS NEO 6M (RX)
• D21: Connected to Adafruit ADXL345 (SDA/SDIO)
• D22: Connected to Adafruit ADXL345 (SCL)

GPS NEO 6M

• VCC: Connected to Battery 18650 (+)
• RX: Connected to ESP32 (TX2)
• TX: Connected to ESP32 (RX2)
• GND: Connected to ESP32 (GND)

Adafruit ADXL345

• VIN: Connected to Battery 18650 (+)
• GND: Connected to ESP32 (GND)
• SDA/SDIO: Connected to ESP32 (D21)
• SCL: Connected to ESP32 (D22)

SIM800L

• VCC: Connected to 5V Battery (+)
• GND: Connected to ESP32 (GND)
• RST: Connected to ESP32 (GND)
• RXD: Connected to ESP32 (D27)
• TXD: Connected to ESP32 (D26)

Battery 18650

• +: Connected to GPS NEO 6M (VCC), Adafruit ADXL345 (VIN)
• -: Connected to ESP32 (GND)

Buzzer

• +: Connected to ESP32 (D25)
• GND: Connected to ESP32 (GND)

5V Battery

• +: Connected to SIM800L (VCC)
• -: Connected to ESP32 (GND)

Code Documentation

// Real-time Accident Detection System using ESP32, GSM800L, GPS, and Buzzer
// This code detects accidents using an accelerometer, triggers a buzzer, and
// sends an alert message with GPS location via GSM module.

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_ADXL345_U.h> // Accelerometer library
#include <TinyGPS++.h> // GPS parsing library
#include <WiFi.h> // Wi-Fi library
#include <SoftwareSerial.h> // SoftwareSerial for SIM800L GSM module

// Pin definitions
#define BUZZER_PIN 25
#define GSM_RX_PIN 27
#define GSM_TX_PIN 26
#define GPS_RX_PIN 16
#define GPS_TX_PIN 17
#define ACCEL_SDA_PIN 21
#define ACCEL_SCL_PIN 22

// GSM setup (SIM800L GSM module)
SoftwareSerial gsmSerial(GSM_RX_PIN, GSM_TX_PIN); // RX, TX pins for GSM module

// GPS setup
TinyGPSPlus gps;
HardwareSerial gpsSerial(2); // Use hardware serial 2 for GPS

// Accelerometer setup
Adafruit_ADXL345_Unified accel = Adafruit_ADXL345_Unified(12345);

// Global variables
bool accident_detected = false;
String latitude = "0.0";
String longitude = "0.0";

// Threshold for accident detection
#define THRESHOLD 5.0

void setup() {
  Serial.begin(115200); // For debugging
  gsmSerial.begin(9600); // GSM baud rate
  gpsSerial.begin(9600, SERIAL_8N1, GPS_RX_PIN, GPS_TX_PIN); // GPS baud rate
  pinMode(BUZZER_PIN, OUTPUT); // Buzzer output pin

  // Accelerometer initialization
  if (!accel.begin()) {
    Serial.println("Accelerometer not detected! Check connections.");
    while (1);
  }
  accel.setRange(ADXL345_RANGE_16_G);

  // Wi-Fi connection setup (though we're not using it here, kept in case for other use)
  WiFi.begin("Your_SSID", "Your_PASSWORD");
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to Wi-Fi...");
  }
  Serial.println("Wi-Fi connected.");
}

void loop() {
  if (detectAccident()) {
    triggerBuzzer();
    String location = getLocation();
    sendAlert(location);
    delay(30000); // Prevent duplicate alerts within 30 seconds
  }
}

bool detectAccident() {
  sensors_event_t event;
  accel.getEvent(&event);
  // Check if any axis acceleration exceeds the threshold
  if (abs(event.acceleration.x) > THRESHOLD || 
      abs(event.acceleration.y) > THRESHOLD || 
      abs(event.acceleration.z) > THRESHOLD) {
    accident_detected = true;
    Serial.println("Accident detected!");
  }
  return accident_detected;
}

void triggerBuzzer() {
  digitalWrite(BUZZER_PIN, HIGH); // Turn on buzzer
  delay(10000); // Keep buzzer on for 10 seconds
  digitalWrite(BUZZER_PIN, LOW); // Turn off buzzer
  Serial.println("Buzzer triggered!");
}

String getLocation() {
  String loc = "Lat: 0.0, Lon: 0.0";
  while (gpsSerial.available() > 0) {
    if (gps.encode(gpsSerial.read())) {
      if (gps.location.isUpdated()) {
        latitude = String(gps.location.lat(), 6);
        longitude = String(gps.location.lng(), 6);
        loc = "Lat: " + latitude + ", Lon: " + longitude;
        Serial.println("Location fetched: " + loc);
        break;
      }
    }
  }
  return loc;
}

void sendAlert(String location) {
  gsmSerial.println("AT+CMGF=1"); // Set SMS text mode
  delay(1000);
  gsmSerial.println("AT+CMGS=\"9087654321\""); // Set recipient number
  delay(1000);
  gsmSerial.print("Accident detected! Location: ");
  gsmSerial.print(location);
  gsmSerial.write(26); // End SMS with CTRL+Z
  delay(1000);
  Serial.println("Alert sent via GSM!");
}

void makeCall() {
  gsmSerial.println("ATD+9087654321;"); // Make a call
  delay(1000);
  Serial.println("Call initiated!");
}

This code initializes the ESP32, GSM800L, GPS NEO 6M, and Adafruit ADXL345 accelerometer. It continuously monitors the accelerometer for any sudden changes in acceleration that exceed a predefined threshold, indicating a potential accident. If an accident is detected, the buzzer is triggered, and an alert message with the GPS location is