MeshCore-mtbeacon

A fork of MeshCore that adds a Meshtastic beacon to a MeshCore repeater: the repeater periodically retunes to the Meshtastic channel, emits real Meshtastic packets, then returns to its MeshCore channel — so it shows up on a Meshtastic network without being a Meshtastic node.

The whole add-on lives under examples/meshtastic_beacon/. Everything else in this tree is unmodified MeshCore — see the upstream project for the base firmware.

What it does

• Silent presence — sends Meshtastic NodeInfo + Position, so the repeater appears as a named node and a pin on the Meshtastic map (no chat spam).
• Occasional announcement — a chat text (MeshCore repeater in range) posted rarely, paced off the repeater's own MeshCore flood advert.
• Region/preset aware — computes the exact Meshtastic default-channel frequency the way Meshtastic firmware does; per-region TX-power caps; per-board hw_model so it reports the right hardware.
• Good citizen — listen-before-talk, interval jitter, EU duty-cycle hold, and off-channel airtime bounding.
• Runtime CLI — mtbeacon on|off|status|send|interval|text.mult|preset|region|… over serial or an admin remote-CLI session. Nothing is hard-coded.

It's integrated into simple_repeater behind -D WITH_MT_BEACON, so a stock repeater build (without the flag) is byte-identical to upstream.

Firmware

Pre-built images for 63 boards (nRF52840 / ESP32-S3 / ESP32-C3 / ESP32-C6 / RP2040 / STM32WL, with SX1262 / SX1276 / LR1110 radios) are attached to the latest release. Flash the one for your board, then configure it over the CLI (mtbeacon help).

Nearly every repeater-capable MeshCore board now has a *_repeater_mtbeacon env — the release covers the whole fleet that builds cleanly from this tree.

Build it yourself

Each board has a *_repeater_mtbeacon PlatformIO env, e.g.:

pio run -e Heltec_t114_repeater_mtbeacon     # nRF52 + SX1262
pio run -e RAK_4631_repeater_mtbeacon
pio run -e Heltec_v3_repeater_mtbeacon       # ESP32-S3

To add the beacon to another board: extend that board's repeater env with -D WITH_MT_BEACON -I examples/meshtastic_beacon (and optionally -D MT_HW_MODEL=<n> for the Meshtastic hardware id).

Tests

Pure logic (frequency math, channel hash, protobuf encoders) has host unit tests — no hardware needed:

examples/meshtastic_beacon/test/run.sh

CI runs these plus representative builds on every push.

Documentation

• examples/meshtastic_beacon/README.md — full reference (CLI, flashing, caveats)
• examples/meshtastic_beacon/INTEGRATION.md — exactly how it hooks into simple_repeater

License

MIT, same as upstream MeshCore (see license.txt). Not affiliated with the MeshCore or Meshtastic projects.

Built with generative AI

The beacon add-on, its docs, and this fork's tooling were developed with the assistance of generative AI (Anthropic's Claude), then reviewed and tested by a human. Read the source, verify on-air behavior, and test before relying on it.