Back to School with STEM-Limited-Time Event(Aug 6-Sep 5)
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Description
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
🔹 Schematic
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):
| Component | Part | Qty |
|---|---|---|
| MCU | ESP32-C3 SuperMini | 1 |
| Relay | G5NB-1A-E-DC5V (5V, 10A) | 8 |
| Driver | ULN2803 | 1 |
| Power | HLK-PM01 (AC-DC 230V → 5V) | 1 |
| DC Reg | LM2596 Buck Converter | 1 |
| LEDs + Resistors | Status indicators | 8 |
| Misc. | Diodes, Caps, Connectors | Various |
| Relay | ESP32-C3 GPIO |
|---|---|
| RLY1 | D0 |
| RLY2 | D1 |
| RLY3 | D2 |
| RLY4 | D3 |
| RLY5 | D4 |
| RLY6 | D5 |
| RLY7 | D6 |
| RLY8 | D7 |
(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
Example Find Here
- Connect ESP32-C3 SuperMini via USB
- Select ESP32-C3 Dev Module in Arduino IDE
- Upload chosen firmware
- Open Serial Monitor @ 115200 baud
- 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)
