Complete Home Automation IoT System

Wi-Fi controlled home automation system with up to 16 relay channels — evolved through 3 versions from prototype to professional wall-installed PCB, controlling all home lighting and appliances via smartphone

Project Overview

Designed and deployed a complete Wi-Fi home automation system capable of controlling up to 16 independent relay channels (lighting circuits, appliances, fans, etc.) via smartphone over a local Wi-Fi network. The project evolved through 3 versions — from a hand-etched prototype to a professionally manufactured and wall-installed production board.

Version 3 — Final Production Board

V3 final production board — 16-channel relay board with DIN-rail compatible screw terminals, ULN2003 driver ICs, and ESP8266 Wi-Fi module socket. Top view (left) and bottom view showing clean professional PCB trace routing (right).

Design Evolution

Version 1 — Prototype

V1 prototype — hand-etched PCB with ESP8266 (Wemos D1), 8-channel relay bank, screw terminals, and TP-Link Wi-Fi router for local network hosting.
  • Hand-etched PCB
  • 8 relay channels
  • ESP8266 (Wemos D1) for Wi-Fi control
  • External TP-Link router for network
  • Basic relay switching validated

Version 2 — Wall Installation

V2 installed inside a recessed wall electrical enclosure — SMPS power supply, 16 relay channels across two boards, ESP8266 module, and fully wired home circuits with color-coded cabling. Green status LEDs confirm active relay channels.
  • Expanded to 16 relay channels (two relay boards)
  • Installed in a wall-recessed metal electrical enclosure
  • Dedicated SMPS for clean power
  • Full home circuit wiring with color-coded cables
  • Green channel-status LEDs

Version 3 — Professional Manufactured PCB

"Smart Controller" Android app — 5 configurable control panels for managing all relay channels from a smartphone over Wi-Fi.
  • Single-board 16-channel design — all relays on one custom manufactured PCB
  • ULN2003 IC arrays for reliable relay driver isolation
  • DIN-rail compatible screw terminal blocks on all sides
  • ESP8266 module socket for easy replacement
  • Clean professional PCB fabrication — green solder mask, silkscreen
  • Smart Controller Android app — 5 control panels, Wi-Fi control from smartphone

Key Features

  • 16 Independent Relay Channels — control lighting circuits, fans, appliances, and more
  • Wi-Fi Control — ESP8266 based, controllable from any smartphone on the local network
  • ULN2003 Driver Isolation — protects MCU from relay coil back-EMF
  • SMPS Power Supply — reliable regulated power for relay coils and logic
  • Wall Installation Ready — V2 and V3 designed for in-wall electrical enclosure mounting
  • Scalable Architecture — modular relay board design expandable per floor/room

Hardware Architecture

Block Implementation
Wi-Fi Controller ESP8266 (Wemos D1 / NodeMCU) — HTTP/MQTT relay control
Relay Driver ULN2003 IC arrays — relay coil isolation and switching
Relays 16× blue relays — 250VAC / 10A rated per channel
Power SMPS — 5V/12V regulated rails for logic and relay coils
Outputs Screw terminal blocks — live/neutral circuit connections per channel
Status Green LEDs — per-channel visual confirmation

Key Achievements

✅ Designed and deployed a complete Wi-Fi home automation system
✅ Evolved from 8-channel prototype to 16-channel professional manufactured PCB
✅ Successfully installed in wall electrical enclosure with full home circuit wiring
✅ Controlled all home lighting and appliances via smartphone over Wi-Fi
✅ Three design iterations progressively improving reliability and installation quality