📌 Project Overview
This project is an Arduino‑based alarm system designed for the Davidson Computers course.
It uses an ultrasonic distance sensor to detect movement, an LCD display to show system status,
and a buzzer to sound an alarm when an object enters the detection range.
🔌 Wiring Diagram
This alarm system uses an Arduino Uno connected to a breadboard, an ultrasonic distance sensor,
a piezo buzzer, and an LCD display. The distance sensor detects movement or proximity, and the
Arduino triggers the buzzer and updates the LCD when an object enters the detection range.
📍 Ultrasonic Distance Sensor (HC-SR04) Wiring
- VCC → 5V on Arduino
- GND → GND on Arduino
- TRIG → Digital Pin 9
- ECHO → Digital Pin 10
📍 Buzzer Wiring
- Positive (+) → Digital Pin 7
- Negative (–) → GND
📍 LCD Display (I2C Module) Wiring
- SDA → A4
- SCL → A5
- VCC → 5V
- GND → GND
📍 Breadboard Connections
- All GND lines tied together on the breadboard
- 5V rail used to power the LCD and distance sensor
- Signal wires routed cleanly to Arduino digital pins
🔧 Hardware Used
- Arduino Uno microcontroller
- HC-SR04 Ultrasonic Distance Sensor
- Buzzer / Piezo alarm
- LCD Display with I2C module
- Breadboard
- Jumper wires
- USB cable for power and programming
💡 How It Works
The ultrasonic sensor sends out sound waves and measures how long they take to bounce back.
When an object comes within a set distance, the Arduino activates the buzzer and updates the LCD
to show an alert message. This creates a simple but effective motion‑triggered alarm system.
🧠 Code Summary
The Arduino code calculates distance using the HC‑SR04 sensor, compares it to a threshold,
and triggers the alarm if the object is too close. The LCD displays real‑time distance readings
and alarm messages.
📈 Skills Demonstrated
- Microcontroller programming
- Sensor integration
- Circuit design and prototyping
- LCD communication using I2C
- Debugging and iterative development
- Documentation and presentation
🚀 Possible Improvements
- Add a keypad for arming/disarming
- Integrate a louder siren or relay‑controlled device
- Add LED indicators for system status
- Send alerts via Bluetooth or Wi‑Fi
- Implement a real‑time clock for logging events