Skip to content

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 Google Chrome, open the repeater configuration tool:
    https://config.meshcore.dev
  2. After connecting, check the Ottawa Repeater ID List to ensure your repeater ID is unique.
  3. Repeater IDs come from the first two characters of the public key.
  4. Duplicate IDs cause conflicts.
  5. Developers are working on a long-term fix, but for now each repeater should use a unique ID.

Generating a New Repeater ID (If Required)

There are two ways to assign a new repeater ID, we recommend option 1 as it guarantees you will get a unique ID

Option 1 — Manually Generate a Private Key (choose your own ID)

  1. Go to the Ottawa Repeater ID List and pick an unused 2-digit ID.
  2. Visit mc-keygen: https://gessaman.com/mc-keygen/
  3. Enter your chosen 2-digit ID, then click Generate Key.
  4. Copy the Private Key from the output.
  5. Open the MeshCore Flasher, click Console, and select your repeater.
  6. Run: set prv.key
  7. Reboot the repeater.
    It will now use this private key, and the public key will match your chosen ID.

Option 2 — Reflash (automatic key generation)

  1. Reflash the repeater and ensure Erase Flash is used.
  2. A new private/public keypair will be generated.
  3. After flashing, verify that the new ID is not in use by checking:
    Ottawa Repeater ID List

Final Configuration Steps

  1. Give the repeater a descriptive name (e.g., Callsign_R1, Downtown_R1).
  2. Set an admin password — this is required for MeshCore Remote Administration.
  3. Apply the Ottawa defaults:
    910.525 MHz / BW 62.5 kHz / SF7 / CR5
  4. Click Save and reboot.

  5. Reconnect using the configuration tool and click Send Advert.

  6. If everything is working, nearby companion nodes will receive it.

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.