Building a Voice Controlled Home Automation System with Arduino

The Voice Controlled Home Automation System operates by integrating wireless communication, infrared transmission, microcontroller logic, and electromechanical switching to manage external devices. At its core, an Arduino Nano processes incoming command signals and dictates the state of various output peripherals. Powering the entire system is a Hi-link 5V 3W power supply module, which efficiently steps down AC mains voltage to a stable 5V DC rail suitable for digital logic. For wireless operation, an HC-05 Bluetooth module pairs with an Android Voice Control App, capturing spoken commands and relaying text-based serial data to the Arduino Nano. When a specific command is received, the microcontroller triggers discrete control channels. Four separate 5V relays, each protected by a reverse-biased 1N4007 diode to prevent voltage spikes during de-energization, are driven by S8050 NPN transistors paired with 1K ohm base resistors. These relays act as electrically isolated switches capable of handling higher-load appliances connected via 10A screw terminals. In parallel, visual feedback is provided by four 5MM LEDs limited by 470 ohm resistors. Additionally, the system incorporates a VS1838 IR sensor and a 5MM IR LED, managed via the IRMP library alongside the FastLED library, allowing the circuit to transmit and receive infrared signals for multi-modal control. Wires, perfboard, cable sleeves, and pin headers ensure secure physical interconnects throughout the assembly.