3-Mode Bluetooth Robot Car

Arduino IDE

Robot Chassis

Geared DC Motor

HC-SR04 Ultrasonic Sensor

Arduino Uno Rev3

SG90 Micro Servo

HC-05 Bluetooth Module

MIT App Inventor 2

L298N Motor Driver Dual H-Bridge

Soldering kit

18650 Lithium cell

<html><body><h3>About '3-Mode Bluetooth Robot'</h3><p>A simple robot car can generally be controlled in one way as it is programmed to operate in certain way.</p><blockquote>What if the same robot can switch between 3 modes of control instantaneously with minimal to no delay?</blockquote><ol><li>The 3-mode Bluetooth Robot is capable enough to be controlled in any of the 3 modes (Manual, Auto and Voice) instantaneously from one Android app.</li><li>Some more features are included for each mode in the app to enhance the functionality of the robot car.</li></ol><figure><iframe src="https://youtu.be/4jAYXDv8F4I"></iframe></figure><h3>Features</h3><ol><li> Wireless control with Bluetooth</li><li> Dedicated Android app</li><li> Manual control using buttons on app</li><li> PWM based 3 levels of motor speed control.</li><li> Ultrasonic sensor based autonomous mode with direction display on the app.</li><li> Voice control using Google Speech Recognizer along with obstacle detection feature to avoid collision.</li></ol><h3>Hardware</h3><p><strong>Robot Overview</strong></p><p>The robot car is developed by modifying an existing RC car.</p><p>The body and motors of the car are kept intact while the included electronics are replaced with new components/modules.</p><p>Robot can be assembled on chassis as shown in the snapshot.</p><figure><img src="https://projects.arduinocontent.cc/022230a0-f55f-499e-a4f1-b62a449b6370.png"/><figcaption>Component Placement on the Car</figcaption></figure><h3>Software</h3><ol><li>To program the microcontroller <strong>Arduino IDE</strong> is used which is commonly used with Arduino development boards.</li><li>In addition certain libraries are required for proper functioning of the microcontroller and interfaced components.</li></ol><p><strong>Libraries</strong></p><ol><li>Servo</li><li>Soft PWM</li></ol><h3>Android App</h3><p>The Android app is developed on <strong>MIT App Inventor</strong> platform.</p><figure><img src="https://projects.arduinocontent.cc/eef4d217-19a8-4b65-9453-ef7b802e6e54.png"/><figcaption>App Overview</figcaption></figure><h3>Working</h3><p><strong>Connecting to App</strong></p><ol><li>Connect/Disconnect button is provided in the app to connect with the robot car via Bluetooth.</li><li>HC-05 module is used for Bluetooth communication.</li></ol><ol><figure><img src="https://projects.arduinocontent.cc/d69ebdf9-d00b-4219-985e-cf75a8f33304.png"/><figcaption>Connecting Robot with the App</figcaption></figure><p><strong>Manual Mode</strong></p></ol><ol><li>The robot is controlled manually using buttons in the app.</li><li>PWM based 3 levels of motor speed control is implemented in the app which enables speed change on the go without delay.</li><figure><img src="https://projects.arduinocontent.cc/fe91a136-6719-4191-8474-1ead8860a2ce.png"/><figcaption>Manual Mode</figcaption></figure><p><strong>Automatic Mode</strong></p></ol><ol><li>This mode is autonomous where the robot finds its own path detecting obstacles with the help of ultrasonic sensor and servo motor.</li><li>The app displays the direction in which the robot is moving.</li><figure><img src="https://projects.arduinocontent.cc/bab5a6c1-d24c-4533-b88c-1722d49989e4.png"/><figcaption>Automatic Mode</figcaption></figure><p><strong>Voice Mode</strong></p></ol><ol><li>The robot is controlled using voice commands provided by the user in the app using Google Speech Recognizer.</li><li>The robot car first scans for obstacle before executing the voice command and then proceeds.</li><li>It stops when an obstacle is detected by ultrasonic sensor and does not obey the command further displaying 'Obstacle Detected' on the opp.</li></ol><ol><figure><img src="https://projects.arduinocontent.cc/d039790e-14ee-44a1-9048-4525881dd691.png"/><figcaption>Voice Mode</figcaption></figure><p></p></ol><ol><p><strong></strong></p></ol><ol><p><strong></strong></p></ol></body></html>

Arduino Code for 3-Mode Bluetooth Robot Car

MIT App Inventor Files

Circuit Connections

3-Mode Bluetooth Robot Car

Robot car developed using Arduino that can operate in 3 modes - Manual, Automatic and Voice with additional features. The car is controlled wirelessly via Bluetooth with a dedicated Android app.