This project is a basic yet powerful Security Alert System built using Arduino Uno, PIR Motion Sensor, Ultrasonic Sensor, Buzzer, and an LCD Display. It is designed to detect intrusions or movement and provide instant feedback both visually (on LCD) and audibly (via buzzer).
- 🚨 Motion Detection using PIR Sensor
- 📏 Distance Measurement using Ultrasonic Sensor (HC-SR04)
- 🔊 Real-time Alerts using a Buzzer
- 📺 LCD Display shows distance to the object
- 💡 Expandable and suitable for home/college security applications
| Component | Quantity |
|---|---|
| Arduino Uno | 1 |
| PIR Motion Sensor | 1 |
| Ultrasonic Sensor (HC-SR04) | 1 |
| Piezo Buzzer | 1 |
| 16x2 LCD Display | 1 |
| 10k Resistor / Potentiometer | 1 (used for LCD contrast, optional) |
| Breadboard | 1 |
| Jumper Wires | As needed |
- VCC → 5V
- GND → GND
- TRIG → Digital Pin 3
- ECHO → Digital Pin 4
- VCC → 5V
- GND → GND
- OUT → Digital Pin 2
- +ve (long leg) → Digital Pin 5
- -ve (short leg) → GND
| LCD Pin | Arduino |
|---|---|
| VSS | GND |
| VDD | 5V |
| V0 | Middle pin of Potentiometer (or GND for low contrast) |
| RS | Pin 12 |
| RW | GND |
| E | Pin 11 |
| DB4 | Pin 10 |
| DB5 | Pin 9 |
| DB6 | Pin 8 |
| DB7 | Pin 7 |
| A (LED+) | 5V |
| K (LED-) | GND |
- System remains in Idle Mode, monitoring motion using the PIR sensor.
- If motion is detected, the ultrasonic sensor calculates the distance to the object.
- The buzzer is activated.
- The LCD displays the message:
"Intruder Detected!"and shows the distance in cm. - After a few seconds, the system resets and returns to idle.
The code is provided in the main.ino file (you can add this name when you upload the code to GitHub). Make sure to have the LiquidCrystal library installed. It comes by default with the Arduino IDE.
- Add a GSM module for SMS alerts
- Integrate with IoT platforms for remote monitoring
- Add camera or RFID for verification
- Add LED indicators for silent alerts
- Devang Gandhi
- Project for College Security/IoT Lab
- GitHub: Dev4057 (https://github.com/Dev4057)
This project is open-source and available under the MIT License.