A compact, scalable, multi-protocol communication platform designed for modern smart homes.
Built around a powerful ESP32-S3, with plug-in radio modules for Zigbee/Thread and Proprietary RF.
Reliable power architecture, clean RF design, and automatic module detection.
This system uses a three-board modular hub architecture:
Contains the ESP32-S3 with native Wi-Fi + Bluetooth LE, full power management, Ethernet support, and the universal expansion bus.
A dedicated 2.4 GHz radio module supporting Zigbee, Thread, and Matter over Thread with a high-efficiency antenna.
A flexible low-power 2.4 GHz module for custom protocols, legacy devices, and private links.
The Main Board can run standalone using Wi-Fi and BLE even with no module attached.
Most smart-home hubs are:
- Locked to one brand or protocol
- Difficult to expand
- Closed hardware
- Not modifiable or repairable
- Dependent on cloud services
- Not designed for RF noise isolation
This project solves these issues with a fully documented, open, modular, serviceable platform.
- Native Wi-Fi + BLE
- USB programming
- JTAG debugging
- I²C bus for module identification
- SPI bus shared with expansion modules
- Presence-detect signal
- Ethernet PHY
- Local battery backup
- Clean, isolated power rails
If no radio module is plugged in, the board still supports:
- Wi-Fi control
- BLE provisioning
- Local automation
- OTA updates
- Zigbee 3.0
- Thread 1.3
- Matter over Thread
- High-efficiency chip antenna or external u.FL
- SPI + IRQ communication
- Local low-noise LDO
- EEPROM with module ID
- Hardware reset & enable control
- SWD header for development
- RF noise isolation
- Easy upgrades
- Thermal and EMI improvements
- Lower main-board complexity
- 2.4 GHz bidirectional transceiver
- SPI interface
- IRQ line
- CE line for TX/RX control
- Local LDO for clean RF power
- On-board EEPROM for identification
- Legacy systems
- Private, encrypted links
- Ultra-low-power sensors
- Custom protocols
- 12 V input
- Step-down to 5 V
- 3.3 V LDO for logic
- Local LDOs for each RF module
- Battery charger & backup
- Inrush, surge, ESD protection
- Proper decoupling everywhere
- Dedicated LDO
- Ferrite-bead power filtering
- Enable pin for power control
- RF-clean power domain
Every expansion module includes a 24AA02E48 EEPROM that stores:
- Unique EUI-48
- Module type ID
The ESP32 reads the EEPROM via I²C on boot and:
- Identifies the module type
- Powers only the selected module
- Loads the appropriate firmware configuration
- TVS on power rails
- ESD protection on connectors
- Solid ground planes
- RF-clean routing
- Ferrite-bead domain separation
- Reverse-polarity protection
- Controlled RF impedance paths
- Fully modular — plug-in radio modules
- Upgradable — replace modules anytime
- Main board works standalone
- Automatic detection via EEPROM
- Clean RF design with isolated power
- Open hardware
- Supports Wi-Fi, BLE, Zigbee, Thread, Matter, Proprietary RF
- Future-proof platform
- Easy to manufacture & repair
- Power the Main Board with 12 V
- Plug in a Zigbee or Proprietary RF module
- Firmware reads the module EEPROM
- Selected module is powered via EN_LDO
- ESP32 configures SPI/I²C pins
- Start using the hub via Wi-Fi, BLE, or RF
- Download design files
- Open schematic and PCB in KiCad
- Review:
- Power sections
- Module connector
- RF networks
- Decoupling and filtering
- Manufacture PCBs
- Assembly order:
- Power stage
- ESP32-S3 main board
- Expansion connectors
- RF module components
- Antennas
- Flash the ESP32-S3 via USB
- Flash EFR32 module via SWD (if needed)
- Test and integrate with your smart-home backend
This project is licensed under the CERN Open Hardware Licence Version 2 - Weakly Reciprocal (CERN-OHL-W-2.0). See the CERN-OHL-W-2.0 ↗ file for more information.