How to Make an Arduino Radar System with Ultrasonic Sensor and Servo Motor

🧠 Introduction

Radar systems are used in defense, automation, robotics, and navigation. In this DIY project, we’ll build a Radar System using Arduino, an HC-SR04 ultrasonic sensor, and a servo motor to scan the environment. The system will sweep a certain angle, detect objects, and visualize them as radar blips on a screen using Processing (optional).

This project is ideal for students, hobbyists, and developers who want to dive into object detection and servo control using Arduino.

⚙️ Components Required

• Arduino Uno or Nano

• HC-SR04 Ultrasonic Sensor

• SG90 Servo Motor

• Jumper Wires

• Breadboard

• USB Cable

• Optional: Processing Software (for radar visualization on PC)

🔌 Circuit Diagram and Pinout

Pin Connections:

Pinout Tip:
Connect the ultrasonic sensor and servo carefully to avoid voltage drops. Use external power for the servo if it jitters.

💡 How It Works

1. The servo motor rotates the ultrasonic sensor from 0° to 180° and back.

2. At each angle, the sensor sends out ultrasonic waves and waits for the echo.

3. The time taken for the echo to return is used to calculate the distance.

4. The distance and angle are either:

   • Displayed in the Serial Monitor, or

   • Visualized on a radar GUI via Processing software.

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     🧾 Arduino Code

     #include <Servo.h>

     const int trigPin = 9;
     const int echoPin = 10;
     Servo myServo;

     void setup() {
     Serial.begin(9600);
     myServo.attach(6);
     pinMode(trigPin, OUTPUT);
     pinMode(echoPin, INPUT);
     }

     void loop() {
     for(int angle = 0; angle <= 180; angle++){
     myServo.write(angle);
     delay(30);
     long duration, distance;
     digitalWrite(trigPin, LOW);
     delayMicroseconds(2);
     digitalWrite(trigPin, HIGH);
     delayMicroseconds(10);
     digitalWrite(trigPin, LOW);
     duration = pulseIn(echoPin, HIGH);
     distance = duration * 0.034 / 2;

     Serial.print(angle);
     Serial.print(“,”);
     Serial.println(distance);
     }

     for(int angle = 180; angle >= 0; angle–){
     myServo.write(angle);
     delay(30);
     long duration, distance;
     digitalWrite(trigPin, LOW);
     delayMicroseconds(2);
     digitalWrite(trigPin, HIGH);
     delayMicroseconds(10);
     digitalWrite(trigPin, LOW);
     duration = pulseIn(echoPin, HIGH);
     distance = duration * 0.034 / 2;

     Serial.print(angle);
     Serial.print(“,”);
     Serial.println(distance);
     }
     }

   • 🎯 Optional: Radar Visualization Using Processing

     1. Download and install Processing.

     2. Use the Serial data from Arduino to plot a radar-style UI.

     3. Code is available online or we can help generate a custom one for your readers.

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     🪛 Assembly Instructions

     1. Mount the ultrasonic sensor on top of the servo motor using glue or double-sided tape.

     2. Connect wires as per the pinout diagram.

     3. Upload the Arduino code via the Arduino IDE.

     4. Open the Serial Monitor to see live distance data.

     5. Use Processing for a visual radar interface.

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     🌿 Applications

     • Object detection in robotics

     • Entry-level radar simulation

     • Surveillance or obstacle alert systems

     • Educational electronics projects

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     🔄 Advanced Upgrades

     • Display radar data on an OLED display

     • Add buzzer alerts for specific distance thresholds

     • Build a 360° rotating base for full scan

     • Connect to a mobile app using Bluetooth or Wi-Fi