ESP32 C3 Super Mini: 8-Channel Relay Control for Home Automation

This project is an 8-channel relay controller based on the ESP32-C3 SuperMini.
It provides multi-platform IoT support out of the box for:

• 🌐 Blynk IoT Cloud
• 🛰️ Arduino IoT Cloud
• 🖥️ Home Assistant (via MQTT)
• 🗣️ Amazon Alexa voice control
• 🎤 Google Home voice control
• 🏠 Tasmota Firmware (for power users)
• 🔥 Google Firebase integration

✨ Features:

• ✅ 8 relays (up to 250VAC / 10A each)
• ✅ Works with Wi-Fi, Cloud, Voice Assistants
• ✅ Physical switches with independent sync (hotel-light style)
• ✅ EEPROM save (state remembered after reboot)
• ✅ Multi-firmware support (Arduino, Tasmota, etc.)
• ✅ Compact PCB design with onboard PSU

🔹 PCB Layout

Main components (see BOM.xlsx for full list):

(Adjust firmware if using different pins.)

You can flash any firmware depending on your ecosystem:

• Supports mobile + web dashboard
• Auto reconnect & sync
• EEPROM save

👉 Example sketch: Find Here

• Works with Arduino Cloud dashboards
• Control relays from app & web
• OTA firmware updates

👉 Example sketch: Find Here

• Flash Tasmota & use MQTT/Home Assistant
• Auto-discovery in Home Assistant
• Web dashboard built-in

👉 Use template in Tasmota:

{"NAME":"ESP32C3-8CH","GPIO":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"FLAG":0,"BASE":18}

(Edit GPIO mapping for relays D0–D7)

• Store relay states in cloud
• Sync between multiple devices

👉 Example: Find Here

• Works via Sinric Pro or ESP Alexa library
• Voice control of each relay: “Alexa, turn on Relay 1”

👉 Example: Find Here

• Connect via MQTT
• Supports two-way sync
• YAML auto-discovery

👉 Example config in configuration.yaml:

switch:
  - platform: mqtt
    name: "Relay 1"
    state_topic: "esp32c3/relay1/state"
    command_topic: "esp32c3/relay1/set"
    payload_on: "ON"
    payload_off: "OFF"
    retain: true

1. Connect ESP32-C3 SuperMini via USB
2. Select ESP32-C3 Dev Module in Arduino IDE
3. Upload chosen firmware
4. Open Serial Monitor @ 115200 baud
5. Control relays from Blynk / Arduino Cloud / Alexa / Google Home / Home Assistant 🎉

• Smart home automation
• Appliance control
• IoT-based remote switching
• Voice-enabled devices
• Industrial automation

• Energy monitoring add-on
• OTA updates across all firmware versions
• Matter protocol support (for full Google/Alexa native integration)
  
  Thanks TO EasyEDA And OSHWLab