ESP32-C6 Matter over Thread Router/Repeater

Pre-compiled firmware to turn an ESP32-C6-DevKitC into a Matter over Thread router that extends your Thread mesh network.

What is this?

This firmware transforms your ESP32-C6 into a mains-powered Thread router that:

• Extends the range of your Thread network
• Acts as a relay for battery-powered Thread devices
• Integrates with Home Assistant and other Matter controllers
• Requires no WiFi configuration - uses Thread only

Perfect for improving connectivity to Thread devices that are far from your border router!

Hardware Requirements

• ESP32-C6-DevKitC (or compatible ESP32-C6 board)
• USB cable for flashing and power
• 8MB flash (most ESP32-C6 boards have this)

Flashing Instructions

Prerequisites

Install esptool:

pip install esptool

Flash the Firmware

1. Connect your ESP32-C6 to your computer via USB

2. Find the serial port:

   # Linux/Mac
   ls /dev/tty* | grep -E 'USB|ACM'
   
   # Usually /dev/ttyACM0 on Linux or /dev/cu.usbserial-* on Mac

3. Erase the flash (recommended for clean install):

   esptool.py --chip esp32c6 --port /dev/ttyACM0 erase_flash

4. Flash the firmware:

   esptool.py --chip esp32c6 --port /dev/ttyACM0 --baud 921600 \
     --before default_reset --after hard_reset write_flash \
     --flash_mode dio --flash_freq 80m --flash_size 8MB \
     0x0 bootloader.bin \
     0xc000 partition-table.bin \
     0x20000 light.bin

5. Monitor the output (optional but recommended):

   python3 -m serial.tools.minicom /dev/ttyACM0 115200
   # Or use: screen /dev/ttyACM0 115200

Replace /dev/ttyACM0 with your actual port.

Adding to Home Assistant

Default Credentials

• Manual Pairing Code: 34970112332
• Discriminator: 3840
• Setup PIN: 20202021

Commissioning Steps

1. Power on your ESP32-C6 (via USB or 5V power supply)

2. In Home Assistant:

   • Go to Settings → Devices & Services
   • Click Add Integration
   • Select Matter
   • Choose Add Matter device

3. Enter the manual pairing code: 34970112332

4. Follow the prompts to complete commissioning

5. The device will join your Thread network and appear as a light device (the actual light control only controls the RGB LED on the ESP32 - the device functions as a router regardless)

⚠️ Important: Provisioning Multiple Devices

If you're flashing multiple ESP32-C6 boards with this firmware:

• Commission devices ONE AT A TIME
• Power off or move away other un-commissioned devices while setting up each one
• All devices share the same pairing code, so the controller may get confused if multiple are advertising simultaneously
• Once commissioned, each device gets a unique identity on your network

Verifying Router Status

After commissioning, the device should show as a "Routing end device" or "Router" in Home Assistant's Thread integration.

If it shows as "End device" instead:

1. Go to Settings → Add-ons → Matter Server
2. Find your ESP32-C6 device
3. Click "Reinterview device"
4. Wait for the reinterview to complete
5. The device should now properly show as a routing device

You can verify Thread network topology at: Settings → Devices & Services → Thread → View Network

Source & Build Information

This firmware is based on:

• ESP-IDF v5.5.2 - Espressif IoT Development Framework
• ESP-Matter - Espressif's Matter SDK
• Example: esp-matter/examples/light (configured for Thread-only operation)

Key Configurations

• OpenThread FTD (Full Thread Device) enabled
• WiFi disabled (Thread only)
• Matter commissioning with default test credentials
• 8MB flash partition scheme for larger firmware

Building from Source

If you want to build this firmware yourself:

# Clone and setup ESP-Matter
git clone --recursive https://github.com/espressif/esp-matter.git
cd esp-matter
./install.sh
. ./export.sh

# Configure and build
cd examples/light
idf.py set-target esp32c6
idf.py menuconfig  # Disable WiFi, enable OpenThread
idf.py build

# Binaries will be in: build/bootloader/bootloader.bin, 
# build/partition_table/partition-table.bin, build/light.bin

See the ESP-Matter documentation for detailed build instructions.

Troubleshooting

Device not commissioning

• Make sure only one un-commissioned device is powered on
• Check that your Thread border router is operational
• Verify the device is visible via BLE (should advertise for pairing)

Device not extending network range

• Verify it shows as "Router" or "Routing end device" (try reinterviewing if not)
• Check Thread network topology in Home Assistant
• Ensure the device is positioned within range of existing Thread infrastructure

License

This firmware uses components from ESP-IDF and ESP-Matter, both licensed under Apache 2.0.

Contributing

Found an issue? Have improvements? Please open an issue or pull request!

Disclaimer

This firmware uses test/development credentials (discriminator 3840, PIN 20202021). For production use, you should provision unique credentials per device. This is suitable for home/hobbyist use.