top of page

BLUETOOTH-CONTROLLED CAR USING ARDUINO UNO & HC-05

Screen Shot 2022-04-11 at 8.27.55 PM.png

PROJECT OVERVIEW:

Designed and implemented an individual major mechatronics project under LE/EECS1011Z – Computational Thinking through Mechatronics.

This project demonstrates the design and implementation of a Bluetooth-controlled robotic vehicle developed using Arduino Uno  and an HC-05 wireless Bluetooth transceiver module. The system enables wireless control of the car through a smartphone application (Arduino Bluetooth RC Car App), allowing users to send directional commands via serial communication over Bluetooth.

Unlike traditional RF or IR remote systems, this setup utilizes Bluetooth serial communication (UART protocol) for real-time, short-range, low-latency control. The car’s movement is driven by DC motors connected through an L298N dual H-bridge motor driver, enabling bidirectional motion with precise control logic implemented in embedded C++.

                            SYSTEM ARCHITECTURE AND WORKING PRINCIPLES:
​

  1. Controller Layer (Arduino Uno): Processes input characters (‘F’, ‘B’, ‘L’, ‘R’, etc.) received from the smartphone via the HC-05 Bluetooth module using the UART serial interface at 9600 bps.

  2. Communication Layer (HC-05 Module): Establishes wireless Bluetooth link with the smartphone. Commands transmitted by the app are interpreted as ASCII values and passed to the Arduino’s RX pin.

  3. Actuator Layer (L298N Motor Driver): Converts Arduino’s low-current logic signals into high-current outputs to drive the DC motors. Two H-bridge circuits control motor direction, enabling forward, reverse, left, right, and stop functions.

  4. Power Supply System: Powered by a 3.7 V / 1100 mAh lithium-ion battery, providing energy to both the logic and motor subsystems through regulated voltage lines.

​

The control logic, implemented in C++, utilizes digitalWrite() operations to manipulate motor direction pins dynamically. The code also includes conditions for additional operations such as LED toggling (O and s commands).

                                                                                    HARDWARE COMPONENTS USED:

​

  • Arduino Uno - microcontroller board serving as the processing unit.

  • HC-05 Bluetooth Module  wireless serial transceiver for smartphone communication.

  • L298N Dual H-Bridge Motor Driver  controls bidirectional rotation of DC motors.

  • Geared DC Motors (×4) provides locomotion and torque to the car chassis.

  • Lithium-Ion 3.7 V Battery Pack  power supply unit.

  • Jumper Wires & MDF Base – physical connections and chassis structure.

​

                       
                   TECHNICAL HIGHLIGHTS:
​

  • Implemented UART serial communication protocol for data transfer between smartphone and Arduino.

  • Designed embedded control logic using conditional branching to handle multiple movement commands.

  • Integrated pulse-based motor control for smooth directional transitions.

  • Ensured modular circuit layout with safe voltage regulation and pin protection.

  • Used event-driven programming principles for real-time command execution.

                                                                                    KEY TECHNICAL TAKEAWAYS:

​

  • Developed firmware in embedded C++ for real-time command handling via UART serial interface.

  • Designed a multi-component control system integrating sensors, actuators, and communication modules.

  • Applied electromechanical design principles for optimized power delivery and motor efficiency.

  • Built a complete circuit architecture with safe load balancing and logic-level voltage separation.

  • Gained hands-on experience in IoT system design, hardware and software integration, and wireless communication protocols.

  • Strengthened ability to debug embedded control systems and translate algorithms into functional, real-world mechatronic models.

  • Acquired foundational knowledge relevant to autonomous vehicles, industrial automation, and connected mobility solutions.

bottom of page