This project is a smart Arduino-based alert system that integrates three types of sensors: ultrasonic distance, PIR motion, and a water level sensor. It uses LEDs and a buzzer to alert users of varying conditions in the environment.
- Red & Yellow LEDs for visual feedback
- Buzzer for dynamic audible alerts
- PIR Sensor to detect movement
- Ultrasonic Sensor to detect proximity
- Water Sensor to detect water level
- Arduino Uno (or compatible)
- PIR Sensor
- Ultrasonic Sensor (HC-SR04)
- Analog Water Sensor
- Red & Yellow LEDs
- Buzzer
- Resistors (2x 220Ω for LEDs)
- Breadboard + Jumper wires
Here’s a quick look at each component used in this project so you know exactly what you're working with.
| Component | Image | Description |
|---|---|---|
| Arduino Uno |  |
Main microcontroller that runs the entire system and connects to all sensors and outputs. |
| PIR Sensor |  |
Detects motion through infrared signals. Triggers the buzzer when movement is detected. |
| Ultrasonic Sensor (HC-SR04) |  |
Measures the distance of nearby objects using sound waves. Used for proximity detection. |
| Analog Water Sensor |  |
Senses water levels through conductivity. Classifies as Dry, Medium, or High. |
| Red LED |  |
Indicates danger or high alert conditions (e.g., motion or high water level). |
| Yellow LED |  |
Signals caution states like medium water levels or distant objects. |
| Buzzer |  |
Outputs different sound patterns based on the detected sensor condition. |
| Breadboard |  |
Used to prototype the circuit without soldering. Connects all components together. |
| Jumper Wires |  |
Connects components to the Arduino and to each other via the breadboard. |
| 220Ω Resistors |  |
Limits current to LEDs to prevent burning them out. One per LED is recommended. |
| Sensor Type | Condition | Response |
|---|---|---|
| Ultrasonic | Very close (distance<10) |
Red + Yellow ON, long buzzer beep |
Medium (10<=distance<=20) |
Red ON, medium buzzer beeps | |
Far (distance>200) |
Yellow ON, short buzzer beeps | |
| PIR Motion | Motion detected | Red ON, high-pitch alarm pattern |
| Water Sensor | High water level | Red ON, long buzzer beep |
| Medium water level | Yellow ON, short buzzer beeps | |
| Dry | All OFF |
| Component | Arduino Pin | Breadboard Note |
|---|---|---|
| Red LED | D7 | Connect through 220Ω resistor to GND rail |
| Yellow LED | D6 | Connect through 220Ω resistor to GND rail |
| Buzzer | D8 | Connect + to D8, - to GND rail |
| Ultrasonic TRIG | D3 | Connect directly |
| Ultrasonic ECHO | D4 | Connect directly |
| PIR Sensor OUT | D2 | Connect directly |
| Water Sensor | A0 | VCC to 5V, GND to GND, Signal to A0 |
| All GNDs | GND | Connect all to ground rail of breadboard |
| Power | 5V | Use 5V pin to power sensors and breadboard |
- Upload the included Arduino code to your Uno board using the Arduino IDE.
- Connect components according to the wiring table and Fritzing diagram.
- Open Serial Monitor (9600 baud) to view live sensor readings.
- Observe the buzzer and LEDs respond to motion, proximity, and water level.
Website: rashaalsaleh.com | Email: [email protected] | LinkedIn: @rasha-alsaleh