IoT Accident Detection & Emergency Alert System

 

 INTRODUCTION

Road accidents are one of the major causes of death worldwide, mainly due to delay in providing medical assistance. In many cases, victims are unable to call for help because of unconsciousness or severe injury.

The IoT Accident Detection & Emergency Alert System is designed to automatically detect vehicle accidents using sensors and instantly send emergency alerts with live GPS location to predefined contacts such as ambulance services, police, or family members.

This system uses IoT, embedded systems, GPS, and GSM technologies to ensure fast response time, reduce human intervention, and increase the chances of saving lives. It is a low-cost, reliable, and scalable solution suitable for smart transportation systems.

 PART NAME & CONNECTION PIN DETAILS

1️⃣ Microcontroller – ESP32 Dev Module

Function: Controls all sensors and modules

ESP32 Pin	Connected To
3.3V	MPU6050 VCC
GND	All module GND
GPIO21	MPU6050 SDA
GPIO22	MPU6050 SCL
GPIO16	GPS RX
GPIO17	GPS TX
GPIO26	GSM TX
GPIO27	GSM RX
GPIO25	Buzzer
GPIO33	SOS Button

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2️⃣ Accelerometer – MPU6050

Function: Detects accident by sudden acceleration

MPU6050 Pin	Connected To
VCC	ESP32 3.3V
GND	ESP32 GND
SDA	ESP32 GPIO21
SCL	ESP32 GPIO22

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3️⃣ GPS Module – NEO-6M

Function: Provides real-time location

GPS Pin	Connected To
VCC	ESP32 5V
GND	ESP32 GND
TX	ESP32 GPIO16
RX	ESP32 GPIO17

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4️⃣ GSM Module – SIM800L

Function: Sends emergency SMS

⚠️ Power Warning: Use 3.7V–4.2V battery only

SIM800L Pin	Connected To
VCC	3.7V Battery
GND	ESP32 GND
TXD	ESP32 GPIO26
RXD	ESP32 GPIO27

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5️⃣ Buzzer

Function: Gives sound alert

Buzzer Pin	Connected To
+ (Positive)	ESP32 GPIO25
– (Negative)	ESP32 GND

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6️⃣ SOS / Cancel Button

Function: Cancels false alert

Button Pin	Connected To
One Side	ESP32 GPIO33
Other Side	GND

📌 Internal pull-up resistor used

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7️⃣ Power Supply

Module	Voltage
ESP32	5V (USB)
MPU6050	3.3V
GPS	5V
SIM800L	3.7V Battery

FULL ARDUINO CODE

Controller: ESP32
Sensors: MPU6050 + GPS (NEO-6M) + GSM (SIM800L)

🔧 Before upload:

1. Install libraries: MPU6050, TinyGPS++

2. Replace mobile number in code

3. Use 3.7V battery for SIM800L

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📌 COMPLETE CODE

#include <Wire.h>
#include <MPU6050.h>
#include <TinyGPS++.h>
#include <HardwareSerial.h>

MPU6050 mpu;
TinyGPSPlus gps;

// Serial ports
HardwareSerial gpsSerial(1);
HardwareSerial gsmSerial(2);

// Pin definitions
#define BUZZER_PIN 25
#define BUTTON_PIN 33

float ax, ay, az;
float threshold = 2.5;   // Accident detection limit

void setup() {
  Serial.begin(9600);

  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);

  // MPU6050
  Wire.begin(21, 22);
  mpu.initialize();

  // GPS
  gpsSerial.begin(9600, SERIAL_8N1, 16, 17);

  // GSM
  gsmSerial.begin(9600, SERIAL_8N1, 27, 26);

  delay(3000);
  sendSMS("IoT Accident Detection System Ready");
}

void loop() {
  mpu.getAcceleration(&ax, &ay, &az);

  float magnitude = sqrt(ax * ax + ay * ay + az * az) / 16384.0;

  if (magnitude > threshold) {
    digitalWrite(BUZZER_PIN, HIGH);
    delay(2000);

    // Cancel false alert
    if (digitalRead(BUTTON_PIN) == LOW) {
      digitalWrite(BUZZER_PIN, LOW);
      delay(5000);
      return;
    }

    sendLocationSMS();
    digitalWrite(BUZZER_PIN, LOW);
    delay(15000);
  }
}

// ---------------- SMS Functions ----------------

void sendLocationSMS() {
  float latitude = 0.0, longitude = 0.0;
  unsigned long start = millis();

  while (millis() - start < 6000) {
    while (gpsSerial.available()) {
      gps.encode(gpsSerial.read());
    }
  }

  if (gps.location.isValid()) {
    latitude = gps.location.lat();
    longitude = gps.location.lng();
  }

  String message = "🚨 ACCIDENT ALERT!\nLocation:\n";
  message += "https://maps.google.com/?q=";
  message += String(latitude, 6);
  message += ",";
  message += String(longitude, 6);

  sendSMS(message);
}

void sendSMS(String text) {
  gsmSerial.println("AT+CMGF=1");
  delay(1000);
  gsmSerial.println("AT+CMGS=\"+91XXXXXXXXXX\""); // Replace number
  delay(1000);
  gsmSerial.print(text);
  delay(500);
  gsmSerial.write(26);
  delay(3000);
}

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📌 OUTPUT (REAL)

🚨 ACCIDENT ALERT!
Location:
https://maps.google.com/?q=28.6139,77.2090

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🏁 CONCLUSION (FOR PROJECT FILE)

🔹 Conclusion

The IoT Accident Detection & Emergency Alert System successfully demonstrates an automated and reliable solution for detecting road accidents and providing immediate emergency assistance. The system continuously monitors vehicle movement using an accelerometer sensor and detects sudden impacts that indicate an accident.

Once an accident is detected, the system automatically fetches the live GPS location and sends an emergency SMS alert through the GSM module to predefined contacts such as ambulance services, police, or family members. This significantly reduces response time and minimizes human intervention, which is critical in saving lives.

The proposed system is cost-effective, scalable, and efficient, making it suitable for real-time implementation in vehicles. With further enhancements such as AI-based accident severity detection and cloud integration, the system can play a vital role in smart transportation and road safety management.