Project Overview

The project involves building a mobile robot—likely using an Arduino microcontroller—that autonomously follows a person by measuring distances with ultrasonic sensors.

Core Components

Based on similar DIY projects, the typical components include:

• Arduino UNO – The main controller handling sensor data and motor commands.

• Ultrasonic Sensors (e.g., HC‑SR04) – Often three, placed at the front, left, and right to measure distances to obstacles or a person

• Motor Driver (e.g., L298N or L293D) – Interfaces between the Arduino and DC motors to control movement .

• DC Motors with Chassis – Providing locomotion, usually two-wheel setups on a chassis.

• Power Supply – Batteries such as Li-ion cells to power the motors and Arduino.

• Wiring and Breadboard – For rapid prototyping and connections.

Wiring and Circuit Design

• Sensors: Each ultrasonic sensor has Trigger and Echo pins connected to digital I/O pins on the Arduino. Power and ground are common.

• Motors: DC motors connect via the motor driver to the Arduino. The driver receives direction and speed signals through control pins.

• Power Management: The motor driver handles higher voltage/current for motors, while Arduino runs from regulated 5 V.

Operational Logic

1. Reading Distances: The Arduino continuously reads distances from the ultrasonic sensors (front, left, right).

2. Decision Making: Based on sensor values, the robot decides whether to:

   • Move forward (if the person is ahead),

   • Turn left or right (if the person is off to the side),

   • Stop or back up (if too close) .

3. Motor Commands: Depending on logic, the Arduino commands the motor driver to move the robot in the appropriate direction.

Example logic from similar projects:

• If the front sensor distance is below a threshold, move forward.

• If left distance is less than right, turn left; if right less, turn right.

• If too close, stop or reverse .

Software & Code Structure

• Setup (setup()):

  • Initialize sensor pins (Trigger as OUTPUT, Echo as INPUT).

  • Configure motor driver control pins.

  • Start serial communication (for debugging).

• Loop (loop()):

  • Read sensor distances via functions (e.g., sensorOne(), sensorTwo(), sensorThree()).

  • Print distances (optional).

  • Compare readings to thresholds.

  • Call movement functions: moveForward(), turnLeft(), turnRight(), stop(), moveBackward(), etc.

  • Repeat continuously .

Applications & Extensions

• Real-World Uses: Shopping cart robots, luggage carriers, assistance robots in public spaces, pet-like companions, surveillance bots, hospital assistance, etc. .

• Beyond Basic: You could enhance the robot by adding line sensors for obstacle detection, integrating Bluetooth or camera modules, or improving targeting via machine vision.