// guide · meshcore

Set up a MeshCore repeater

Guide · updated June 2026

A repeater is what actually grows the mesh — a headless node you mount up high to relay traffic for everyone. It takes more care than a companion, so you’ll flash it, lock it down, set it to 3-byte, and test it on the bench before it ever goes up a pole.

New to MeshCore? Start with Set up your first MeshCore node — this guide assumes you’ve flashed a companion before.

// what you need

Before you start

  • A LoRa board to live as a repeater — a Heltec V3/V4 is common; a low-power nRF52840 (RAK WisBlock) is ideal for solar. Update it to firmware v1.14.1 or newer (required for 3-byte).
  • A good 915 MHz antenna — on a repeater this matters more than anything; upgrade from the stock whip.
  • A real USB data cable (charge-only cables won’t show the board to your computer) and Chrome or Edge.
  • For deployment: a weatherproof enclosure and reliable power (battery / solar / PoE).

Antenna first, always. Connect the correct antenna for your frequency before you power or transmit. A bare LoRa board transmitting into no antenna can damage itself.

// the process

Flash, configure, deploy

  1. Antenna on, then plug in

    Connect the antenna, plug the board into your computer with a real data cable, and open the MeshCore web flasher in Chrome or Edge. If the flasher can’t see the board, a charge-only cable is the #1 culprit — try a different cable/port.

  2. Flash the Repeater role

    Pick your exact board target, choose the Repeater role, flash, and reboot when it finishes. Unlike a companion, a repeater is headless — no Bluetooth, no phone app; it just relays.

  3. Run Repeater Setup & lock it down

    In the flasher’s Repeater Setup, name the node and set the Region / Preset to US. Set both the admin and guest passwords and write them down — never leave defaults on something you’re mounting in public.

  4. Set 3-byte IDs (our repeater standard)

    Connect to the repeater’s USB console and switch it to 3-byte paths. Skip any 2-byte advice — our area runs 1-byte companions, 3-byte repeaters. (Needs firmware v1.14.1+. Why 3-byte? → MeshCore IDs & avoiding collisions.)

    # on the repeater's console
> set path.hash.mode 2
> reboot

    While you’re in there, sync the clock (Settings → Sync Clock) so timestamps line up, then reboot.

  5. Test on the bench — before you mount anything

    Confirm it actually relays from another MeshCore device first. New nodes announce with adverts that take time to propagate, so be patient and send/discover one. It’s far easier to fix a cable, setting, or antenna on the bench than 30 feet up a mast.

  6. Mount it high

    Height wins. Mount as high as is practical and safe, antenna vertical and clear of metal and obstructions, in a weatherproof enclosure with reliable power. Then confirm it on MeshMapper / CoreScope — showing up clean and conflict-free.

Check for ID conflicts. Once it’s live, open MeshMapper → Region Info → Repeater List → Repeater ID Usage and make sure your repeater isn’t red (conflicting). The IDs guide walks through that grid.

Back it up before it goes up. Save the repeater’s private key and settings (a “rebuild kit”) so a future reflash or board swap restores it identically — you don’t want to climb back up just to re-adopt a new identity. See MeshCore backup & key security.

Stuck? Repeater siting is half art — the #meshcore channel in the RF Lab Discord has people who’ve mounted plenty. Ask away.

// links

Tools & sources

Web Flasherflash firmware & Repeater Setup MeshCoremeshcore.io JRat Techworks — Repeater Guidedetailed flashing walkthrough MeshCore IDs & collisionswhy repeaters use 3-byte Set up a companion nodethe 1-byte starter guide MeshMappercheck coverage & ID conflicts Backup & key securitysave the key before you mount it

Put up a repeater, grow the mesh.

Coverage gaps, antenna picks, mounting tips — bring them to #meshcore.

Join the Discord Open MeshMapper →