A basic radar detection system that utilises Arduino UNO, ultrasonic sensor, servo motor, LED's and an active buzzer.
This project implements a simple radar-style object detection system using an Arduino Uno, an ultrasonic sensor, and a servo motor to scan the environment.
The system continuously rotates the ultrasonic sensor across a defined angular range and measures the distance to nearby objects. When an object is detected within a predefined threshold distance, the system provides both visual and auditory feedback using LEDs and a buzzer while delaying completion of rotation until the object is removed.
This project demonstrates the integration of sensor data acquisition, actuator control, and real-time feedback systems in an embedded robotics platform.
- Environment scanning using a rotating ultrasonic sensor
- Distance measurement using time-of-flight principles
- Servo-based angular sweep for directional sensing
- Real-time object detection alerts
- Visual indication using LEDs
- Audible alert using a buzzer
- Modular embedded code structure
- Arduino Uno
- Ultrasonic Distance Sensor (HC-SR04 or equivalent)
- Servo Motor (SG90 or similar)
- Active buzzer
- Red LED (object detected warning)
- Green LED (no object detected)
- Current limiting resistors for LEDs
- Breadboard
- Jumper wires
- External power source (optional for servo stability)
The system consists of three main subsystems:
An ultrasonic sensor measures the distance to nearby objects by emitting a sound pulse and measuring the return time of the reflected signal.
A servo motor rotates the ultrasonic sensor across a predefined angular range (e.g., 0°–180°). This allows the system to detect objects across a wider field of view.
When the measured distance falls below a specified threshold:
- A red LED turns on
- A buzzer sounds an alert
If no object is detected within the threshold distance:
- A green LED remains on
- VCC → Arduino 5V
- GND → Arduino GND
- Trig → Arduino digital pin
- Echo → Arduino digital pin
- VCC → Arduino 5V (or external supply)
- GND → Arduino GND
- Signal → PWM pin on Arduino
Green LED:
- Cathode → Digital pin via resistor
- Anode → GND
Red LED:
- Anode → Digital pin via resistor
- Cathode → GND
- Positive → Digital pin
- Negative → GND
- The servo motor begins sweeping the ultrasonic sensor across a specified angular range.
- At each angle position:
- The ultrasonic sensor emits a pulse.
- The echo return time is measured.
- The distance to the nearest object is calculated.
- If the detected distance is below a predefined threshold:
- The red LED turns on
- The Radar is delayed
- The buzzer is activated
- If the detected distance is above the threshold:
- The green LED remains active
- The buzzer stays off
- The scanning process repeats continuously.
Radar.Operation.Demo.mp4
This Arduino Radar project successfully demonstrates the integration of hardware and software to create a basic object detection and visualization system. By combining an ultrasonic sensor, a servo motor, an Arduino microcontroller, and a Processing-based graphical interface, the system was able to scan the surrounding environment and display detected objects in real time. The radar continuously rotated through a defined angle range, measured distances accurately within the sensor’s operating limits, and transmitted data efficiently for visualization on a computer screen.
Through this project, several important learning outcomes were achieved:
- Embedded Systems Integration: Gained hands-on experience connecting sensors, actuators, and microcontrollers into a complete working system.
- Sensor Data Acquisition: Learned how ultrasonic sensors measure distance using sound wave reflection and how to process timing signals into usable distance values.
- Servo Motor Control: Developed skills in controlling angular movement using PWM signals and coordinating scanning motion.
- Serial Communication: Understood how to send real-time sensor data from Arduino to external software for further processing.
- Programming Skills: Improved proficiency in Arduino C/C++ coding, debugging, and structuring multi-component systems.
- Problem Solving: Addressed practical challenges such as unstable readings, timing delays, synchronization between hardware and software, and sensor limitations.
Overall, the project provided a strong foundation in robotics, automation, and real-time monitoring systems. It also demonstrated how low-cost components can be combined to simulate real-world radar scanning concepts used in security, navigation, and obstacle detection applications.