Sonar - Style Distance Sensing System

Inspiration

I wanted my first mechatronics project to be more than a basic tutorial or isolated experiment. Instead of focusing only on software or only on electronics, I aimed to build a complete system—something that could sense the environment, move physically, and communicate data beyond the microcontroller.

A sonar-style scanning system felt like the perfect starting point. It’s simple in concept, but it naturally combines input, output, timing, and visualization—core ideas in mechatronics.

What This Project Does

This project is a rotating sonar system built using:

• An Arduino Nano
• A servo motor for angular scanning
• An ultrasonic sensor for distance measurement
• A custom 3D-printed mount
• A Python (Pygame) visualization running on a computer

The servo sweeps the ultrasonic sensor across an arc, measuring distances at different angles. That data is sent over serial communication to a Python program, which renders a live sonar-style display on the screen.

System Overview

At a high level, the system works like this:

• The Arduino rotates the servo step-by-step.
• At each angle, the ultrasonic sensor measures distance.
• Angle and distance data are sent over serial.
• A Python program receives and visualizes the data in real time.

This turns a simple sensor-and-motor setup into a full sensing and visualization system.

Servo Control and Timing

The first challenge was controlling the servo smoothly. Instead of jumping directly between angles, I used small incremental movements with short delays between steps.

These delays served two important purposes:

• They reduced jerky servo motion.
• They allowed the ultrasonic sensor enough time to return stable readings.

This was an early lesson in how timing affects physical systems, not just program flow.

Distance Measurement with Ultrasonic Sensor

Once the servo motion was reliable, I added the ultrasonic sensor. The Arduino sends a trigger pulse, measures the echo time, and converts that into distance.

This stage marked the moment when the project started feeling like a real system:

• The sensor provided live input from the environment.
• The servo reacted based on programmed logic.
• The Arduino became the bridge between sensing and motion.

Hardware Stability Improvements

During testing, I noticed occasional servo jitter and unstable behavior. To address this, I added a capacitor across the power supply.

This small hardware change had a noticeable impact:

• Reduced sudden servo movements
• Improved power stability
• Increased overall reliability

It was a strong reminder that hardware design choices matter just as much as code.

Custom 3D-Printed Mount

To make the project more robust and usable, I designed a custom 3D-printed mount for the servo and ultrasonic sensor.

This step introduced new challenges:

• Accurate dimensioning
• Accounting for tolerances
• Iterating through multiple print revisions

After several adjustments, I ended up with a solid enclosure that securely holds both components and maintains proper alignment during scanning.

Real-Time Visualization with Python

Instead of relying on the Arduino Serial Monitor, I wanted to visualize the sonar data in a more meaningful way.

Using Python and Pygame, I created a live sonar-style display that:

• Receives angle and distance data over serial
• Plots detected objects in real time
• Mimics the behavior of a radar/sonar sweep

This step extended the project beyond embedded hardware and demonstrated how microcontroller data can integrate with higher-level software.

Challenges and Lessons Learned

As with any real-world project, there were challenges:

• Serial communication occasionally stopped unexpectedly
• The servo sometimes stalled without a clear cause

Debugging these issues taught me how to:

• Test hardware and software independently
• Question assumptions
• Stay patient and methodical during troubleshooting

Even unresolved quirks became valuable learning experiences.

Why This Project Matters

Although simple in concept, this project brought together:

• Embedded programming
• Electronics and power management
• Mechanical design and 3D printing
• Data communication
• Software visualization

It served as a complete introduction to mechatronics by showing how multiple disciplines come together to form a working system.