4-Channel Home Automation with ESP32 PCB This project is a 4-channel home automation system based on the ESP32, designed to control electrical appliances via Wi-Fi, MQTT, or a mobile app. The custom PCB integrates relays, optoisolated inputs, and an efficient power supply for reliable operation.

Features

✔ ESP32-based Wi-Fi control (supports web server & MQTT).

✔ 4-Channel relay output for appliance control.

✔ Optoisolated inputs for safe external switch connections.

✔ Onboard buck converter (AC/DC to 5V) for efficient power.

✔ Compact PCB design for easy enclosure integration.

Hardware Overview

1️⃣ Components Used:

ESP32-WROOM-32 (Wi-Fi + Bluetooth MCU)

4 x Relays (5V or 12V, SPDT)

Optocouplers for switch inputs

AC to DC Buck Converter (HLK-PM03 or equivalent)

Screw terminals for easy wiring

Status LEDs for each relay & power indicator

2️⃣ PCB Design Details:

Designed in KiCad

2-layer PCB for cost efficiency

Proper relay isolation from low-voltage ESP32

Wide power traces for relay switching

It is open source design by Md Ammar Maniyar for @ampnics