Tutorial MeshCore

Tutorial: MeshCore

What it is. MeshCore is another open LoRa mesh network for off-grid messaging. It uses companion devices and repeater nodes that advertise themselves. OnAir shows nodes (companions, repeaters, rooms), a map, public chat and packet statistics.

Read this first. Receive only. MeshCore encrypts messages. The built-in key of the public channel (MeshCore Public) lets OnAir read that channel. Private channels and direct messages stay encrypted unless you add a channel secret of your own in Channel keys. OnAir does not break keys. Check the rules where you live. See Legal and Privacy.

What you need

• A radio at 2 Msps or more (1 Msps minimum). An RTL-SDR is fine for 62.5 kHz signals.
• An 868 or 915 MHz antenna.
• Frequencies from the database: 869.618 MHz (MeshCore EU 868, narrow preset; the mode start) and 910.525 MHz (MeshCore USA / Canada).

Before you start

MeshCore presets are narrow (62.5 kHz in the database entries). If your capture covers both Meshtastic and MeshCore frequencies, both can be searched at once, with more CPU. Moderate gain.

Step by step

1. In the mode list open IoT & sensors and choose LoRa mesh, 869.618 MHz.
2. Pick your radio and start the receiver.
3. Open Settings and tick MeshCore under Networks.
4. Under MeshCore radio preset pick the preset of your region. A preset fills in the custom LoRa setting and tunes to its frequency. Refresh from meshcore.nz fetches the current preset list; it contacts the internet (api.meshcore.nz) only when you click and sends nothing about you; if it fails, the previous list stays.
5. Check the LoRa setting (bandwidth, spreading factor, coding rate, sync word, preamble); Custom lets you enter your own.
6. Watch Nodes, Map, Chat, Packets and Telemetry.

What you should see

Adverts from nodes with their names and positions, repeaters relaying, and messages on the public channel. The packet counters show types.

Reading the screen

• Nodes: node table with role, name and last heard.
• Map: nodes with positions.
• Chat: public messages (and channels for which you added a key).
• Packets: frames with type, SNR, level and routes.
• Telemetry: measurements.
• Settings: networks, preset, LoRa setting, band plan, Channel keys.

Options and settings

Channel keys: MeshCore takes the channel name and the secret in hex or base64. The default keys are built in. Keys stay in this computer's settings and are never sent anywhere.

Troubleshooting

• No packets. Wrong preset or region. Compare with the settings of a device.
• Adverts but no messages. Direct and private traffic is encrypted.
• Nothing after refreshing presets. Offline or the service down; the built-in list is used.
• Wrong sync word. Check the LoRa setting against the preset.

Tips

Repeaters send adverts regularly; they are the easiest thing to see first.

Legal and privacy notes

Do not publish other people's names or locations.

Under the hood

LoRa physical layer with MeshCore's own framing and encrypted payloads (the public channel uses a published key). The preamble is 32 symbols for SF8 and below, otherwise 16 (see the tooltip in Settings).

Related

Mode-MeshCore, Tutorial-Meshtastic, Tutorial-MeshCom, Tutorial-LoRa-raw, Live-map, Modes, Main-window, Supported-radios, Troubleshooting, FAQ, Legal.