Arduino Voice Controlled Robot

1. Introduction

In this project, we will build a voice-controlled robot using Arduino, where the robot moves based on voice commands given through a smartphone. The commands are sent via Bluetooth using an Android app and received by the Arduino.

This project is widely used in robotics learning, automation, and assistive technology.

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2. Components Required

• Arduino Uno / Nano
• L298N Motor Driver Module
• HC-05 Bluetooth Module
• DC Motors (2 or 4)
• Robot Chassis
• Jumper Wires
• Battery (7.4V / 12V)

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3. Circuit Diagram and Connections

🔌 Connections:

HC-05 Bluetooth:

HC-05	Arduino
VCC	5V
GND	GND
TX	RX (Pin 0)
RX	TX (Pin 1)

L298N Motor Driver:

L298N	Arduino
IN1	Pin 8
IN2	Pin 9
IN3	Pin 10
IN4	Pin 11

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4. Circuit Working

1. User speaks command in mobile app
2. App converts voice → text
3. Text sent via Bluetooth (HC-05)
4. Arduino reads command
5. Motors move accordingly

🎤 Example Commands:

• “forward”
• “backward”
• “left”
• “right”
• “stop”

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5. Arduino Code

char command;

void setup() {
  Serial.begin(9600);

  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
}

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

    if (command == 'F') { // Forward
      digitalWrite(8, HIGH);
      digitalWrite(9, LOW);
      digitalWrite(10, HIGH);
      digitalWrite(11, LOW);
    }

    else if (command == 'B') { // Backward
      digitalWrite(8, LOW);
      digitalWrite(9, HIGH);
      digitalWrite(10, LOW);
      digitalWrite(11, HIGH);
    }

    else if (command == 'L') { // Left
      digitalWrite(8, LOW);
      digitalWrite(9, HIGH);
      digitalWrite(10, HIGH);
      digitalWrite(11, LOW);
    }

    else if (command == 'R') { // Right
      digitalWrite(8, HIGH);
      digitalWrite(9, LOW);
      digitalWrite(10, LOW);
      digitalWrite(11, HIGH);
    }

    else if (command == 'S') { // Stop
      digitalWrite(8, LOW);
      digitalWrite(9, LOW);
      digitalWrite(10, LOW);
      digitalWrite(11, LOW);
    }
  }
}

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6. Code Explanation

• Arduino reads data from HC-05 using Serial
• Each character corresponds to a command
• Motor driver pins control robot movement

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7. Output

• Robot moves according to voice commands
• Controlled wirelessly via smartphone

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8. Applications

• Assistive robotics
• Smart automation
• Hands-free control systems
• Educational robotics

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9. Advantages

• Wireless control
• Easy to operate
• Interactive project
• Good for beginners and advanced users

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10. Conclusion

This project demonstrates how voice commands can be used to control robotic systems. It integrates Bluetooth communication with Arduino, making it a powerful and practical project for real-world applications.

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11. Mobile App Setup (Voice Control App)

🔹 Recommended App

Use:
👉 Arduino Bluetooth Control (Android)

OR search in Play Store:
👉 “Bluetooth Voice Control for Arduino”

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🔹 Install and Setup

Step 1: Install App

• Open Play Store
• Search: Bluetooth Voice Control Arduino
• Install the app

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Step 2: Pair HC-05 Module

1. Turn ON your robot
2. Go to mobile Bluetooth settings
3. Find device:
   👉 HC-05

4. Enter password:

   1234
   

   OR

   0000
   

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Step 3: Connect App

• Open the app
• Click Connect
• Select HC-05

👉 Now your phone is connected to Arduino

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🔹 Voice Commands Setup

Most apps convert voice → text → send characters

Example Mapping:

Voice Command	App Sends	Arduino Action
“Forward”	F	Move forward
“Backward”	B	Move backward
“Left”	L	Turn left
“Right”	R	Turn right
“Stop”	S	Stop

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🔹 How It Works Internally

1. You speak → “Forward”
2. App converts voice → text
3. Converts text → character (‘F’)
4. Sends via Bluetooth
5. Arduino reads and executes

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⚠️ Important Tips (Very Useful)

✔ Speak clearly (simple words only)
✔ Keep phone language = English
✔ Ensure Bluetooth is ON
✔ Keep robot within 5–10 meters