Vehicle Accident Alert System Using ESP8266 & GPS

NodeMCU ESP8266 MPU6050 Accelerometer + Gyroscope NEO-6M GPS Module 16×2 LCD with I2C Module Buzzer LED Resistor for LED Breadboard or Perf Board Jumper Wires | As required 5V Power Supply or 9v battery

Circuit Connections MPU6050 → NodeMCU * VCC → 3.3V * GND → GND * SDA → D2 * SCL → D1 The MPU6050 communicates with the NodeMCU using the I2C protocol. NEO-6M GPS → NodeMCU * VCC → Suitable power supply * GND → GND * TX → D7 * RX → D8 16×2 I2C LCD → NodeMCU * VCC → Suitable power supply * GND → GND * SDA → D2 * SCL → D1 Buzzer → NodeMCU * Buzzer (+) → D5 * Buzzer (−) → GND LED → NodeMCU * LED (+) → D6 through a resistor * LED (−) → GND

Start by connecting the MPU6050 to the NodeMCU using the I2C pins. Upload a simple MPU6050 test program and check the accelerometer and gyroscope values through the Serial Monitor. Make sure the sensor responds when you move or tilt it before integrating it into the complete project.

Connect the NEO-6M GPS module to the NodeMCU and connect the 16×2 I2C LCD to the same I2C bus as the MPU6050. The GPS should ideally be tested outdoors with a clear view of the sky, since getting a GPS fix can be difficult indoors. Once the GPS gets a fix, the module can provide latitude, longitude and speed.

Connect the buzzer and LED, install the required Arduino libraries and configure your Blynk template. Before uploading the final code, replace: { #define BLYNK_TEMPLATE_ID "your_blynk_ID" #define BLYNK_TEMPLATE_NAME "your_Template" #define BLYNK_AUTH_TOKEN "your_blynk_auth_token" } with your own Blynk credentials. Also change: const char* ssid = "your_wifi_ssid"; const char* password = "password"; to your Wi-Fi credentials.

Blynk Virtual Pins * V0 → Speed * V1 → Latitude * V2 → Longitude * V3 → Pitch * V4 → Roll

The project does not use a single sensor value to determine an accident. Instead, it checks two main conditions: 1. Sudden acceleration The accelerometer values are converted into acceleration in terms of g. The code calculates: accelMagnitude = sqrt(fax * fax + fay * fay + faz * faz); If the magnitude exceeds the configured threshold of approximately 2.3 g, the system considers it a potential impact. 2. Excessive vehicle tilt The system calculates: Pitch Roll If either angle exceeds approximately 40°, the system considers the vehicle orientation abnormal. Therefore, the current detection logic is essentially: High acceleration OR Excessive pitch OR Excessive roll ↓ Potential accident detected ↓ Buzzer + LED ↓ Blynk alert These thresholds are configurable and should be calibrated for the specific vehicle and mounting position. A real safety-critical system would require significantly more testing and validation before being relied upon for emergency response.

Raw GPS speed can fluctuate even when the vehicle is stationary. This is normal for GPS modules because of positioning uncertainty and satellite conditions. To reduce this effect, the project uses a simple moving-average filter: const int SPEED_SAMPLES = 8; Small speed readings below 2 km/h are also treated as zero to reduce stationary GPS noise. The GPS coordinates are also rounded before being displayed. LCD Display The LCD provides local feedback from the system. The first line displays: P:10 R:-3 where: P = Pitch R = Roll The second line displays the GPS-derived speed: Spd:25.4kmh If the GPS has not obtained a valid location: GPS Fixing... When an accident condition is detected, the display changes to: !! ACCIDENT !!

Blynk Virtual Pins * V0 → Speed * V1 → Latitude * V2 → Longitude * V3 → Pitch * V4 → Roll The Blynk dashboard allows the user to monitor the vehicle remotely. The dashboard can display: Speed: GPS-derived vehicle speed Latitude: Current GPS latitude Longitude: Current GPS longitude Pitch: Vehicle front/back orientation Roll: Vehicle side-to-side orientation This makes the project more than just an accident alarm — it becomes a basic IoT vehicle monitoring system.

When a potential accident is detected, the system activates the local buzzer and LED and generates a Blynk event. If a valid GPS location is available, the notification contains information such as: Accident Detected! Speed: XX km/h Pitch: XX° Roll: XX° Location: XX, XX Google Maps Link The Google Maps link is generated using: https://maps.google.com/?q=LATITUDE,LONGITUDE If GPS does not have a valid location at the time of detection, the system still sends the accident alert, but indicates that the GPS location is unavailable.

Code is Available on Github