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Flashing and Configuring a Repeater Node

This guide will help you flash a node and configure it as a MeshCore repeater.

RAK Bootloader Update

(Skip this section if you are not using a RAK-based board)

Important:
Before configuring a repeater, you must update the bootloader on RAK boards.
Without this fix, a failed OTA update can brick the repeater and require physical recovery.

Steps

  1. Download the OTA bootloader fix:
    OTAFIX Bootloader UF2 File
  2. Connect your repeater to your computer via USB.
  3. Double-click the button beside the USB port on the RAK board.
  4. The green LED should turn on, indicating DFU mode.
  5. A new USB drive should appear on your computer.
  6. Drag the .uf2 file into the drive.
  7. The copy will appear to fail, and the board will reboot — this is expected.
  8. Open INFO.TXT on the drive and confirm it reports bootloader version 0.9.2.

Flashing MeshCore Repeater Firmware

  1. Plug the device into your computer via USB.
  2. Open the MeshCore Web Flasher: https://flasher.meshcore.co.uk
  3. Select your device hardware.
  4. Select Repeater as the firmware type.
  5. Click Enter DFU Mode.
  6. Click Erase Flash.
  7. Click Flash to install the firmware.

Note:
If flashing fails after erasing, refresh the page, click Enter DFU Mode again, then click Flash.

Configuring a MeshCore Repeater

  1. Using a Chromium-based browser that supports the required serial connection (e.g., Google Chrome or Microsoft Edge), open the repeater configuration tool:
    https://config.meshcore.dev

  2. Connect to your repeater and note the Repeater ID shown in the tool.

  3. The Repeater ID is derived from the keypair (it corresponds to the first byte / first two hex characters of the repeater’s key).

  4. Because there are only 256 possible IDs, overlaps become more likely as the network grows—especially when keys are generated automatically during flashing.

  5. Check the Ottawa Repeater ID List to confirm your repeater ID is not already in use.

  6. If it’s unique, continue configuring the rest of the repeater settings as normal.
  7. If it’s already in use, follow the steps below to assign a new ID.

Assigning a New Repeater ID (if your ID is already in use)

  1. Go to the Ottawa Repeater ID List and choose an unused 2-digit ID.
  2. Click the unused ID to open its key generator page.
  3. Click Generate Key.
  4. Copy the Private Key value.
  5. In the repeater console, set the private key (replace <PRIVATE-KEY> with what you copied):
    set prv.key <PRIVATE-KEY>
  6. Reboot the repeater.

After reboot, the repeater will use the new private key and the public key will correspond to the ID you selected.

Final Configuration Steps

  1. Set a descriptive repeater name (e.g., Callsign_R1, Downtown_R1).
  2. Set an admin password (required for MeshCore Remote Administration).
  3. Apply the Ottawa defaults:
    910.525 MHz / BW 62.5 kHz / SF7 / CR5
  4. Click Save and reboot the repeater.
  5. Reconnect with the configuration tool and click Send Advert.

If everything is working, nearby companion nodes should receive the advert.

Once the repeater has been discovered by your companion node, use Remote Administration to set:

  1. Zero-hop adverts: every 1 hour
  2. Flood adverts: every 12 hours
  3. Click Save

Tip:
After every reboot, you must resync the repeater’s clock.
The repeater will still route messages without a clock, but its adverts will be ignored until the time is set.