Introduction

Voice-controlled robots are an exciting example of combining robotics, IoT, and voice recognition technology. These robots can move forward, backward, turn left, or right based on spoken commands, making them hands-free and highly interactive.

Voice-controlled robots are widely used in smart homes, security, healthcare, and entertainment applications.

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Objective of the Project

• To create a robot that can respond to voice commands
• To implement wireless communication between user and robot
• To demonstrate real-time robotics control using voice
• To promote human-machine interaction

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Working Principle

1. User speaks commands into a mobile app (e.g., Blynk or MIT App Inventor)
2. Commands are sent via Bluetooth or Wi-Fi to the microcontroller
3. Microcontroller interprets commands and drives the motors
4. Robot moves according to the voice instructions

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Components Required

• Arduino Uno / ESP32
• HC-05 Bluetooth Module (for wireless commands)
• Motor Driver Module (L298N)
• DC Motors with wheels
• Robot chassis
• Power Supply (Battery Pack)
• Jumper wires

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Block Diagram

Mobile App (Voice Command)
          ↓
       Bluetooth HC-05
          ↓
      Microcontroller
          ↓
     Motor Driver L298N
          ↓
        DC Motors
          ↓
       Robot Movement

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Circuit Connections (Arduino + HC-05 Example)

HC-05 Bluetooth Module

VCC → 5V
GND → GND
TX  → RX (Arduino)
RX  → TX (Arduino)

Motor Driver L298N

IN1 → Arduino Pin 8
IN2 → Arduino Pin 9
IN3 → Arduino Pin 10
IN4 → Arduino Pin 11
ENA → 5V or PWM Pin
ENB → 5V or PWM Pin
Motor A → Left Wheel
Motor B → Right Wheel

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Arduino Code (Voice Controlled Robot)

#include <AFMotor.h>  // If using Adafruit Motor Shield

#define IN1 8
#define IN2 9
#define IN3 10
#define IN4 11

void setup() {
  Serial.begin(9600); // For Bluetooth
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);
}

void loop() {
  if (Serial.available()) {
    char command = Serial.read();

    switch(command) {
      case 'F': // Forward
        digitalWrite(IN1, HIGH);
        digitalWrite(IN2, LOW);
        digitalWrite(IN3, HIGH);
        digitalWrite(IN4, LOW);
        break;
      case 'B': // Backward
        digitalWrite(IN1, LOW);
        digitalWrite(IN2, HIGH);
        digitalWrite(IN3, LOW);
        digitalWrite(IN4, HIGH);
        break;
      case 'L': // Left
        digitalWrite(IN1, LOW);
        digitalWrite(IN2, HIGH);
        digitalWrite(IN3, HIGH);
        digitalWrite(IN4, LOW);
        break;
      case 'R': // Right
        digitalWrite(IN1, HIGH);
        digitalWrite(IN2, LOW);
        digitalWrite(IN3, LOW);
        digitalWrite(IN4, HIGH);
        break;
      case 'S': // Stop
        digitalWrite(IN1, LOW);
        digitalWrite(IN2, LOW);
        digitalWrite(IN3, LOW);
        digitalWrite(IN4, LOW);
        break;
    }
  }
}

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Code Explanation

• Arduino receives commands from Bluetooth module
• Commands are interpreted as F = Forward, B = Backward, L = Left, R = Right, S = Stop
• Motor driver activates DC motors accordingly
• Robot moves according to voice input

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Advantages

• Hands-free robot control
• Easy to operate
• Can be integrated with AI voice assistants
• Fun and educational robotics project

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Applications

• Home automation robots
• Security and surveillance
• Educational robotics
• Voice-assisted healthcare robots

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Future Enhancements

• Use Wi-Fi + IoT for remote control
• Integrate with Google Assistant or Alexa
• Add obstacle detection for safe movement
• Add camera for live streaming

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Conclusion

The Voice Controlled Robot is a perfect project to demonstrate robotics, IoT, and voice recognition. It is interactive, educational, and innovative, making it ideal for students and hobbyists interested in smart robotics.