Wireless Voice-Controlled Robot - Electronic Engineering Guide
1. Introduction
The Wireless Voice-Controlled Robot project enables users to control a robotic vehicle using voice commands transmitted wirelessly. It combines voice recognition technology with wireless communication to provide hands-free control over robotic movement.
2. Objectives
• Build a robot that can be controlled wirelessly using
voice commands.
• Interface voice recognition module with microcontroller.
• Use wireless communication (Bluetooth) to send commands to the robot.
• Enable real-time and reliable control of the robot's movement.
3. Components Required
• Arduino Uno / Nano
• HC-05 Bluetooth Module
• Voice Recognition Module (e.g., Elechouse V3) or Smartphone App
• L298N Motor Driver
• DC Motors and Robot Chassis
• Wheels and Castor
• 9V or 12V Battery with Connector
• Jumper Wires and Breadboard
4. Working Principle
The system captures voice commands using a voice recognition module or smartphone app, which transmits the command over Bluetooth to the robot. The Arduino processes the command and drives the motors through the L298N motor driver to perform the desired movement.
5. System Architecture
1. Voice command input from user (via mic or app).
2. Bluetooth module receives command on the robot.
3. Arduino decodes the command and controls the motor driver.
4. Robot performs corresponding movement: forward, backward, left, right, or
stop.
6. Circuit Design and Interfacing
• HC-05 TX → Arduino RX, HC-05 RX → Arduino TX (via voltage
divider)
• Voice recognition output or smartphone app connects to HC-05
• L298N IN1/IN2/IN3/IN4 to Arduino D7/D6/D5/D4
• Motor connections to L298N OUT1/OUT2 and OUT3/OUT4
• Power L298N with 9V/12V supply; 5V from L298N to Arduino VIN
7. Microcontroller and Motor Driver Integration
Arduino reads voice command from Bluetooth serial input. Based on recognized command (e.g., 'forward', 'stop'), it sets appropriate HIGH/LOW signals to the L298N inputs to control motor rotation.
8. Voice Recognition and Wireless Communication
Voice recognition can be achieved via:
• Dedicated module (like Elechouse V3) directly connected to Arduino.
• Smartphone voice assistant app linked with Bluetooth terminal app.
Commands are transmitted as text strings to the Arduino over serial Bluetooth
communication.
9. Arduino Code Overview
Sample Code Snippet:
void loop() {
if (Serial.available()) {
String command =
Serial.readStringUntil('\n');
command.trim();
if (command == "forward")
forward();
else if (command ==
"backward") backward();
else if (command == "left")
turnLeft();
else if (command ==
"right") turnRight();
else stop();
}
}
10. Power Supply Considerations
• Motors require a 9V or 12V battery.
• Arduino and HC-05 can be powered via 5V regulator or from L298N’s 5V output.
• Ensure enough current capacity to avoid brownouts during motor operation.
11. Applications
• Assistive technology for disabled users
• Voice-controlled delivery robots
• Educational robotics projects
• Remote-controlled surveillance robots
12. Limitations and Future Enhancements
• Limited range due to Bluetooth (~10 meters).
• Misrecognition of commands in noisy environments.
• Enhancements: Wi-Fi or RF control, obstacle avoidance sensors, integration
with Google Assistant or Alexa.
13. Conclusion
The Wireless Voice-Controlled Robot demonstrates the integration of voice interfaces with embedded systems and wireless communication. It offers a flexible platform for prototyping intelligent robotics systems controlled via human voice.