Build a 3D Ultrasonic Scanner with Arduino & Processing

ArduinoUnoProjex octobre 22, 2025

 

Build a Real-Time 3D Ultrasonic Scanner with Arduino & Processing (Step-by-Step Guide)

In today’s world of DIY electronics and smart sensing, building your own 3D ultrasonic scanner is not only educational—it’s surprisingly accessible. Using just an Arduino Uno, an HC-SR04 ultrasonic sensor, a servo motor, and the free Processing software, you can create a real-time radar-like system that scans your environment and visualizes obstacles in 2D (which simulates a 3D sweep). This project is perfect for robotics enthusiasts, students, hobbyists, and makers looking to understand sensor fusion, data visualization, and serial communication.

In this comprehensive guide, we’ll walk you through every step—from wiring your components to writing and uploading the Arduino code, setting up serial communication, and creating a dynamic visualization in Processing. By the end, you’ll have a fully functional ultrasonic radar scanner that maps distances and angles in real time.

💡 Why This Project Matters: Unlike static distance sensors, this system rotates, captures angular data, and plots it visually—giving you spatial awareness similar to LiDAR systems used in autonomous vehicles (on a much simpler scale).

🛠️ What You’ll Need: Components & Tools

Before diving into code and wiring, gather these essential components:

Hardware:

  • Arduino Uno (or compatible board)
  • HC-SR04 Ultrasonic Sensor
  • SG90 or MG996R Servo Motor (standard 180° servo)
  • Jumper Wires (male-to-male and male-to-female)
  • Breadboard (optional but recommended)
  • USB Cable (for Arduino to PC connection)

Software:

  • Arduino IDE (free, from arduino.cc )
  • Processing IDE (free, from processing.org )
  • USB-to-Serial Driver (usually auto-installed with Arduino IDE)

✅ Pro Tip: Ensure your Arduino drivers are installed correctly. On Windows, check Device Manager for the correct COM port (e.g., COM4).

🔌 Wiring Diagram: Connecting Sensor, Servo & Arduino

Correct wiring is crucial for reliable data. Follow this pin configuration:

HC-SR04 Trigger
Pin 10
HC-SR04 Echo
Pin 11
Servo Signal
Pin 12
Servo VCC
5V
Servo GND
GND
HC-SR04 VCC
5V
HC-SR04 GND
GND

⚠️ Warning: Never connect the HC-SR04 directly to 5V without checking its voltage tolerance. Most versions are 5V-safe, but double-check your module.

Diagram


📜 Arduino Code: Scanning & Sending Data

The Arduino’s job is simple: rotate the servo, fire ultrasonic pulses, calculate distance, and send angle + distance pairs to your PC via serial.

Here’s the complete, optimized code:

cpp
#include <Servo.h>

Servo myServo;

const int trigPin = 10;
const int echoPin = 11;
const int servoPin = 12;

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

void loop() {
for (int angle = 0; angle <= 180; angle += 2) {
myServo.write(angle);
delay(30); // Allow servo to settle

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; // Convert to cm

// Send data as "angle,distance." (note the period)
Serial.print(angle);
Serial.print(",");
Serial.print(distance);
Serial.println(".");
}

// Sweep back
for (int angle = 180; angle >= 0; angle -= 2) {
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.print(distance);
Serial.println(".");
}
}

How It Works:

  1. Servo sweeps from 0° to 180° (and back) in 2° increments.
  2. At each angle, the ultrasonic sensor fires a 10µs pulse.
  3. The echo duration is measured, then converted to centimeters.
  4. Data is sent as a string: "57,45." (angle=57°, distance=45cm, ending with a period).

🔍 Why the period (.)? It acts as a delimiter so Processing knows when a full message ends—critical for parsing.

💻 Setting Up Processing for Real-Time Visualization

Processing is a free, open-source programming language built for visual applications. We’ll use it to receive serial data and draw a live radar display.

Step 1: Install Processing

Download and install from processing.org . No extra libraries needed.

Step 2: Upload This Processing Code

java
import processing.serial.*;

Serial myPort;
String data = "";
float angle = 0;
float distance = 0;

void setup() {
size(800, 600);
smooth();
// Replace "COM4" with your Arduino's port
// On Mac/Linux: "/dev/tty.usbmodemXXXX" or "/dev/ttyACM0"
myPort = new Serial(this, "COM4", 9600);
myPort.bufferUntil('.');
}

void draw() {
background(0);
// Draw radar arcs
stroke(0, 255, 0, 50);
noFill();
for (int r = 50; r < 400; r += 50) {
ellipse(width/2, height, r*2, r*2);
}
// Draw center line
stroke(0, 255, 0);
line(width/2, height, width/2, height - 400);
// Draw scanned points
if (data.length() > 0) {
String[] parts = split(data, ',');
if (parts.length == 2) {
angle = float(parts[0]);
distance = float(parts[1]);
// Convert polar to Cartesian
float x = width/2 + cos(radians(angle - 90)) * map(distance, 0, 200, 0, 350);
float y = height - sin(radians(angle - 90)) * map(distance, 0, 200, 0, 350);
// Draw object
fill(255, 0, 0);
noStroke();
ellipse(x, y, 10, 10);
// Draw sweep line
stroke(255, 0, 0);
strokeWeight(2);
line(width/2, height, x, y);
// Display data
fill(0, 255, 0);
text("Angle: " + nf(angle, 0, 0) + "°", 20, 30);
text("Distance: " + nf(distance, 0, 1) + " cm", 20, 50);
}
}
}

void serialEvent(Serial p) {
data = p.readStringUntil('.');
if (data != null) {
data = trim(data);
}
}

Key Features of This Code:

  • Dynamic radar arcs (green concentric circles)
  • Real-time red dots marking detected objects
  • Sweeping red line showing current scan direction
  • Live angle & distance readout

🔄 Don’t forget: Replace "COM4" with your actual Arduino port (check Arduino IDE > Tools > Port).

RADAR


🔧 Troubleshooting Common Issues

Even seasoned makers hit snags. Here’s how to fix the most frequent problems:

❌ "No Data in Processing"

  • Cause: Wrong COM port or baud rate mismatch.
  • Fix: Verify port in Arduino IDE. Ensure both Arduino and Processing use 9600 baud.

❌ "Servo Jitters or Doesn’t Move"

  • Cause: Insufficient power or incorrect wiring.
  • Fix: Power servo from external 5V if using MG996R. SG90 usually works on Arduino 5V.

❌ "Distance Readings Are Inaccurate"

  • Cause: Sensor noise, soft surfaces, or angles >30° off perpendicular.
  • Fix: Add averaging (e.g., take 3 readings and use median). Keep objects flat and perpendicular.

❌ "Processing Crashes on Startup"

  • Cause: Port not available or syntax error.
  • Fix: Close Arduino Serial Monitor before running Processing. Check for typos in code.

🌐 Why Use Processing? (And Not Python or MATLAB)

While Python (with PySerial + Matplotlib) can do similar visualizations, Processing excels here because:

  • Built-in graphics functions (ellipse, line, text) require minimal code.
  • Event-driven serial handling via serialEvent() is seamless.
  • Zero dependencies—just install and run.
  • Beginner-friendly syntax inspired by Arduino.

🆓 Bonus: Alternatives like p5.js (web-based) or OpenFrameworks exist, but Processing remains the gold standard for quick hardware visualization.

🚀 Advanced Enhancements (Take It Further!)

Once your basic scanner works, consider these upgrades:

1. Add Bluetooth/WiFi

Use HC-05 or ESP8266 to send data wirelessly to a laptop or phone.

2. Log Data to CSV

Modify Arduino code to save scans for later analysis in Excel or Python.

3. 3D Visualization

Use Processing’s P3D renderer to create true 3D point clouds (requires tilt mechanism).

4. Obstacle Avoidance

Integrate with a robot chassis—stop or turn when distance < 20cm.

5. Multi-Sensor Array

Mount 2–3 sensors at different heights for layered scanning.

📊 Understanding the Physics: How Ultrasonic Sensing Works

The HC-SR04 uses time-of-flight measurement:

  1. Trigger: Send 10µs HIGH pulse to Trig pin.
  2. Emit: Sensor sends 8-cycle 40kHz ultrasonic burst.
  3. Echo: Sound bounces off object, returns to sensor.
  4. Measure: pulseIn() measures echo duration (in µs).
  5. Calculate:
    Distance (cm) = (Duration × Speed of Sound) / 2
    Speed of sound ≈ 340 m/s → 0.034 cm/µs

📏 Max Range: ~400 cm (but reliable up to 200–300 cm in practice).

✅ Final Thoughts: Why This Project Is Worth Your Time

Building a 3D ultrasonic scanner with Arduino teaches you:

  • Sensor integration (ultrasonic + servo)
  • Real-time data acquisition
  • Serial communication protocols
  • Polar-to-Cartesian coordinate conversion
  • Creative coding for visualization

It’s a foundational project that bridges physical computing and digital representation—skills directly applicable to robotics, automation, and IoT.

Whether you’re a student preparing for a science fair, a teacher demonstrating physics concepts, or a maker exploring spatial sensing, this scanner delivers immediate visual feedback and endless customization potential.

🔗 Resources & Downloads

Ready to scan your world? Gather your parts, upload the code, and watch your room come alive on screen—one ultrasonic pulse at a time. Don’t forget to like, share, and subscribe for more Arduino projects! 🛠️📡

📌 Pro Reminder: Always unplug your Arduino before rewiring, and double-check power connections to avoid damaging components. 

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Publié par ArduinoUnoProjex

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