Project Hub /Basic Analog & Power Electronics/How to Interface Arduino with an Ultrasonic Sensor?

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₹500 – ₹1,500

3 – 6 Hours

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How to Interface Arduino with an Ultrasonic Sensor?

Learn how to connect an HC-SR04 ultrasonic sensor to an Arduino to measure distance and optionally display results on an I2C LCD.

Originally published on CircuitDigest

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

Arduino UNO R3 Board (Compatible) – ATmega328P Microcontroller with USB Cable Rs. 999.00
Ultrasonic Sensor Module HC-SR04 Rs. 89.00
I2C Module for 16x2 (1602) Character LCD Rs. 109.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

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How It Works

This interactive distance-measurement system operates by coordinating the Arduino Uno board, an HC-SR04 ultrasonic sensor, and an I2C LCD display. The microcontroller triggers the HC-SR04 sensor to emit a brief, high-frequency sound wave burst via its trigger pin. As this acoustic wave travels through the air and bounces off a nearby target object, it generates an echo that returns to the sensor's receiver, which drops the echo pin low to signal reception. By measuring the total elapsed time between the transmission and the return of the sound wave using the Arduino, the system calculates distance based on the known speed of sound in air. Once this numerical distance value is computed, the Arduino communicates the data to the 16x2 character I2C LCD display. The I2C protocol simplifies this readout process by requiring only two data lines (SDA and SCL) in addition to power and ground, allowing the screen to dynamically update and present the real-time distance measurements to the user without complex parallel wiring.

Why Build This

Develop foundational embedded systems knowledge by integrating distance-sensing inputs with visual display outputs for undergraduate robotics applications.

Implement practical obstacle avoidance and proximity detection algorithms used in autonomous mobile robots and automated smart infrastructure.

Master serial communication protocols like I2C to efficiently drive character displays with minimal microcontroller pin usage.

Real-World Application

Distance measurement, obstacle avoidance in robotics, parking sensors, and automated smart dustbins.

Skills You'll Learn

Ultrasonic time-of-flight measurement

I2C communication protocol

digital pin triggering

character LCD interfacing

distance calculation algorithms

Safety Precautions

No specific precautions noted for this build — always follow general electronics safety practices.

Technology Tags

ARDUINO

HC-SR04

ULTRASONIC SENSOR

I2C LCD

SENSORS

C++

SERIAL COMMUNICATION

Frequently Asked Questions

Why does the I2C LCD only require four wires instead of many more?

The I2C protocol uses a two-wire serial interface (SDA for data and SCL for clock) alongside power and ground, which drastically reduces the number of required connections compared to standard parallel LCDs.

How does the HC-SR04 calculate distance?

It emits an ultrasonic sound pulse and measures the time it takes for the echo to bounce back, using the constant speed of sound to convert that travel time into a distance measurement.

Do I need to install any external libraries to make the display and sensor work?

Yes, you will need the LiquidCrystal_I2C library and the Wire library within the Arduino IDE to properly communicate with the I2C display module.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

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