Voice Controlled Home Automation System Using 8051 Microcontroller

Introduction

Home automation systems have become increasingly popular due to their convenience and ease of use. Adding voice control to such systems enhances their accessibility and functionality. This project demonstrates how to design a voice-controlled home automation system using the 8051 microcontroller. The system allows users to control home appliances using voice commands through a Bluetooth-connected smartphone.

Components Required

• 8051 Microcontroller (e.g., AT89S52)

• HC-05 Bluetooth Module

• Voice Recognition Module (e.g., Elechouse V3 or compatible)

• Relay Module (4-channel for controlling multiple appliances)

• 16x2 LCD Display (optional for displaying status)

• Resistors (10kΩ, 1kΩ)

• Capacitors (33pF, 100μF)

• Crystal Oscillator (11.0592 MHz)

• Breadboard and Connecting Wires
  

• Power Supply (5V for the 8051 and Bluetooth module, separate supply for relays)

Circuit Diagram

The 8051 microcontroller interfaces with the HC-05 Bluetooth module for wireless communication and the relay module to control home appliances. The voice recognition module processes voice commands and sends them to the 8051 via UART.

+5V ----- +5V

          |

          |

        HC-05

        +---+

    +5V |VCC| 

    GND |GND|

    TX  |TXD|------- RXD (P3.0 of 8051)

    RX  |RXD|------- TXD (P3.1 of 8051)

         +---+

Voice Recognition Module

    +5V |VCC| 

    GND |GND|

    TX  |TXD|------- RXD (P3.0 of 8051)

    RX  |RXD|------- TXD (P3.1 of 8051)

Relay Module

    VCC to +5V

    GND to Ground

    IN1 to P2.0 (Relay 1 control)

    IN2 to P2.1 (Relay 2 control)

    IN3 to P2.2 (Relay 3 control)

    IN4 to P2.3 (Relay 4 control)

Pin Connections

• HC-05 Bluetooth Module:

• VCC to +5V

• GND to Ground

• TXD to RXD (P3.0 of 8051)

• RXD to TXD (P3.1 of 8051)

• Voice Recognition Module:

• VCC to +5V

• GND to Ground

• TXD to RXD (P3.0 of 8051)

• RXD to TXD (P3.1 of 8051)

• Relay Module:

• VCC to +5V

• GND to Ground

• IN1 to P2.0 of 8051

• IN2 to P2.1 of 8051

• IN3 to P2.2 of 8051

• IN4 to P2.3 of 8051

Software Implementation

The code is written in C using Keil uVision IDE. It involves initializing the UART for communication with the Bluetooth module and voice recognition module, reading commands, and controlling the relays based on these commands.

#include <reg51.h>

sbit RELAY1 = P2^0; // Relay 1 control pin

sbit RELAY2 = P2^1; // Relay 2 control pin

sbit RELAY3 = P2^2; // Relay 3 control pin

sbit RELAY4 = P2^3; // Relay 4 control pin

void delay(unsigned int count) {

    int i, j;

    for(i=0; i<count; i++)

        for(j=0; j<1275; j++);

}

void uart_init(void) {

    TMOD = 0x20; // Timer1 in mode 2

    TH1 = 0xFD; // Baud rate 9600

    SCON = 0x50; // 8-bit data, 1 stop bit, REN enabled

    TR1 = 1; // Start Timer1

}

char uart_receive(void) {

    while(RI == 0); // Wait for reception to complete

    RI = 0; // Clear reception interrupt flag

    return SBUF; // Return received character

}

void main() {

    char command;

    uart_init(); // Initialize UART

    while(1) {

        command = uart_receive(); // Receive command from Bluetooth or Voice module

        switch(command) {

            case 'A': // Turn ON Appliance 1

                RELAY1 = 1;

                break;

            case 'B': // Turn OFF Appliance 1

                RELAY1 = 0;

                break;

            case 'C': // Turn ON Appliance 2

                RELAY2 = 1;

                break;

            case 'D': // Turn OFF Appliance 2

                RELAY2 = 0;

                break;

            case 'E': // Turn ON Appliance 3

                RELAY3 = 1;

                break;

            case 'F': // Turn OFF Appliance 3

                RELAY3 = 0;

                break;

            case 'G': // Turn ON Appliance 4

                RELAY4 = 1;

                break;

            case 'H': // Turn OFF Appliance 4

                RELAY4 = 0;

                break;

            default:

                // Handle unrecognized command

                break;

        }

        delay(100); // Small delay for stability

    }

}

Explanation

1. Initialization:

2. UART Initialization: The uart_init() function configures the UART for communication at a baud rate of 9600.

3. Receiving Commands:

4. The uart_receive() function waits for and reads a character from the Bluetooth module or voice recognition module via UART.

5. Relay Control:

6. The main loop continuously receives commands and uses a switch-case structure to control the relays based on the received commands. Commands 'A' to 'H' are used to turn the appliances on or off.

Conclusion

This project demonstrates the use of the 8051 microcontroller to create a voice-controlled home automation system. By integrating a Bluetooth module and a voice recognition module, the system can receive voice commands and control home appliances accordingly. This project is a great way to learn about wireless communication, voice recognition, and using microcontrollers for home automation applications.

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