🏠 DIY Smart Home Automation Board Using ESP32-C3 and 8-Channel Relay

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Welcome to another exciting DIY project! In this post, I’ll walk you through the design and features of my custom-built ESP32-C3-based 8-Channel Relay Board — a powerful and flexible controller for your smart home automation needs.

🔧 Project Overview

This board is built around the ESP32-C3 SuperMini, offering Wi-Fi control for up to 8 electrical appliances like lights, fans, pumps, or sockets. It’s designed for seamless integration with Home Assistant, Tasmota, ESPHome, or custom Arduino firmware.

With onboard AC-DC power conversion, relay drivers, I2C expansion headers, and extra GPIOs, this is a ready-to-use smart switchboard — ideal for both hobbyists and smart home enthusiasts.

✅ Key Features

  • 🧠 Microcontroller: ESP32-C3 SuperMini (Wi-Fi + BLE)

  • 🔌 Relay Outputs: 8x channels (10A @ 250V AC each)

  • 💡 Relay Driver: ULN2803A

  • ⚡ Power Input: 100–240V AC (HLK-PM01 module)

  • 🔋 Onboard Power Regulation: 5V and 3.3V (via LM2596)

  • 🔄 I2C Expansion: Connect OLED, DHT, BMP, etc.

  • 🔗 GPIO Expansion: 3 extra digital pins available

  • 🏠 Firmware Support: ESPHome, Tasmota, Arduino IDE

🖼️ PCB Preview

(Insert 3D PCB Image, PCB Layout Image, Schematic Image)

The board was designed using EasyEDA and follows proper layout practices with AC-DC isolation, wide power traces, labeled pins, and a compact silkscreen.

⚙️ How It Works

  1. ESP32-C3 controls each relay through GPIOs.

  2. ULN2803A handles high-current relay switching.

  3. Relays receive 5V DC power from onboard HLK-PM01.

  4. ESP32-C3 is powered with regulated 3.3V via LM2596.

  5. Extra headers allow connection of sensors or displays (I2C).

  6. Works with Home Assistant, voice assistants, or custom code.

📦 Components Used

Component Quantity
ESP32-C3 SuperMini 1
5V Relay (10A) 8
ULN2803A 1
HLK-PM01 (AC to 5V) 1
LM2596 Buck Converter 1
LEDs + Resistors 8
Screw Terminals 8
Push Button 1
Custom PCB 1

🔌 Firmware Options

🏠 ESPHome (for Home Assistant)

yaml
switch:
- platform: gpio
pin: GPIO0
name: "Relay 1"
- platform: gpio
pin: GPIO1
name: "Relay 2"
# Repeat for all 8 relays

💻 Arduino IDE Example

Use digitalWrite() on GPIO0 to GPIO7 to control relays.

🌐 Tasmota Template

json
{"NAME":"ESP32-8Relay","GPIO":[0,1,2,3,4,5,6,7],"FLAG":0,"BASE":1}

🛠️ Use Cases

  • Control room lights, fans, and plugs over Wi-Fi

  • Schedule-based automation via Home Assistant

  • Add DHT11 or OLED for temperature display

  • Create voice-controlled switches (Alexa, Google Assistant)

  • Monitor status on your phone or dashboard

📁 Downloads

  • ✅ Gerber files

  • ✅ Schematic PDF

  • ✅ BOM (Bill of Materials)

  • ✅ ESPHome YAML example

  • ✅ Arduino sketch (Coming soon)

📣 Final Thoughts

This ESP32-C3 relay board is a powerful, clean, and modular solution for home automation. Whether you’re building your first smart controller or upgrading your existing setup, this board gives you full control, expansion flexibility, and firmware freedom.

📬 Contact & Credits

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2 thoughts on “🏠 DIY Smart Home Automation Board Using ESP32-C3 and 8-Channel Relay”

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