Meshtastic Working Group

What is Meshtastic?

Meshtastic is an open-source project that turns inexpensive LoRa radios into a powerful, off-grid mesh communication system. With a Meshtastic device, you can send short text messages and GPS locations to others without the need for cellular or internet access—perfect for emergencies, hiking trips, or rural communities.

Meshtastic devices form a mesh network, meaning your messages can hop between radios to reach their destination, even if you're not directly within range. This makes it ideal for decentralized communication in areas with limited infrastructure.


Goals of the Working Group

The ERSN Meshtastic Working Group exists to:

  • Evaluate Meshtastic as a supplement to our GMRS radio net
  • Explore deployment of a regional mesh network
  • Coordinate channel use and best practices
  • Test bridging strategies for linking isolated clusters
  • Promote community adoption and device onboarding

Our long-term vision is a robust, semi-persistent mesh that can serve as a backup communications method that supplements our GMRS net.


Getting Started with Meshtastic

New to Meshtastic? Here's how to begin:

  1. Buy a device
    We recommend starting with the LilyGO T-Echo or T-Beam boards.
  2. Install the firmware
    Use the Meshtastic Flasher to install the latest firmware onto your device.
  3. Download the app
    Get the Meshtastic app for Android or desktop to configure your device, view messages, and monitor network status.
  4. Configure your device
    Use the app to set up your device. Make sure to select the correct region (US), most other settings can stay as default at first.
  5. Join the ERSN Channel
    • Channel name: ERSN
    • Private key: [Click to reveal]
    • Anyone may join, but we reserve the right to make the channel key private in the future to protect network integrity.

Check out Meshtastic's detailed Getting Started Guide for more detailed instructions.


Range and Coverage

Meshtastic devices leverage LoRa (Long Range) radio technology, which offers impressive coverage compared to other license-free options:

  • Urban areas: 0.5-1 mile between nodes
  • Suburban areas: 1-3 miles between nodes
  • Rural/line of sight: 3-10+ miles between nodes
  • Elevated positions: 10-20+ miles with good elevation and antennas

Factors affecting range include:

  • Terrain and obstacles (hills, buildings, dense trees)
  • Antenna quality and placement (higher is almost always better)
  • Device power settings (can be adjusted in the app)
  • Environmental conditions (rain, humidity, etc.)

The mesh architecture means that even with limited individual node range, a network of devices can cover larger areas as messages hop from node to node.


MQTT Bridging

MQTT (Message Queuing Telemetry Transport) is a lightweight messaging protocol designed for constrained devices and low-bandwidth, high-latency networks—perfect for IoT applications.

MQTT bridging allows separated Meshtastic mesh networks to connect over the internet. For example, two mesh networks in different valleys that can't directly communicate via radio can still exchange messages when at least one node from each network has internet access.

  • MQTT host: mqtt.bayme.sh
  • MQTT username: [Click to reveal]
  • MQTT password: [Click to reveal]
  • Topic prefix: msh/US/CA/Motherlode
  • Map reporting: on

You should also update the ERSN channel configuration to have all options enabled (uplink, downlink, position).

WiFi-enabled Meshtastic nodes (like the T-Beam) can act as internet gateways, connecting your local mesh to the wider network. These gateways are typically stationary devices set up at home with permanent power and WiFi, but can also be mobile when connected to hotspots or Starlink in the field.

                       MQTT Broker (Cloud)
                          ┌─────────┐
                ┌─────────│  MQTT   │─────────┐
                │         │ Broker  │         │
                │         └─────────┘         │
                │                             │
           MQTT Bridge via Internet/Grid      │
                │                             │
      ┌─────────┴──────────┐        ┌─────────┴──────────┐
      │ Stationary Gateway │        │ Stationary Gateway │
      │    (Pinebrook)     │        │     (Murphy's)     │
      └─────────┬──────────┘        └─────────┬──────────┘
                │                             │
                │ (wireless mesh)             │ (wireless mesh)
      ┌─────────┼─────────┐         ┌─────────┼─────────┐
      │         │         │         │         │         │
  ┌───┴───┐ ┌───┴───┐ ┌───┴───┐ ┌───┴───┐ ┌───┴───┐ ┌───┴───┐
  │ Mobile│ │ Mobile│ │ Mobile│ │Mobile │ │Mobile │ │Mobile │
  │ Node  │ │ Node  │ │ Node  │ │Node   │ │Node   │ │Node   │
  │  A1   │ │  A2   │ │  A3   │ │ B1    │ │ B2    │ │ B3    │
  └───────┘ └───────┘ └───────┘ └───────┘ └───────┘ └───────┘
      

Note: Bridging requires grid or internet access, so it's not a replacement for true off-grid use. It's best thought of as a way to “stitch” together multiple local meshes when internet is available.

Understanding Node Roles and the "OK to MQTT" Setting

Not all nodes in your mesh need the same MQTT configuration. Understanding the different roles and the critical "OK to MQTT" setting helps ensure proper message propagation between separated mesh networks.

Node Types and Configuration Requirements

  • Gateway Nodes: Stationary nodes with WiFi/internet access that bridge your local mesh to MQTT. These nodes need full MQTT Module configuration (host, username, password, etc.) and must have uplink/downlink enabled.
  • Regular Mesh Nodes: Portable or solar nodes without internet access. These nodes don't need MQTT Module configuration, but they need the "OK to MQTT" setting enabled if you want their messages to propagate through gateway nodes to other meshes.

The "OK to MQTT" Setting

Location: The "OK to MQTT" setting is found under LoRa settings in your Meshtastic device configuration, not in the MQTT Module section. This is separate from the MQTT Module settings that gateway nodes use for broker connection details.

This setting controls whether your node's messages can be uploaded to MQTT brokers by gateway nodes in your mesh:

  • Default: false
  • When enabled: Gateway nodes will forward your messages to MQTT, allowing them to reach other meshes
  • When disabled: Your messages stay within your local mesh only

Important: This is not a cryptographic security feature but a "polite request" enforced by official firmware. It only applies to channels using the default PSK keys—channels with custom encryption keys ignore this setting.

Example Scenario

Consider this five-node setup across two separate mesh areas:

    Area 1 (Pinebrook)        MQTT Cloud        Area 2 (Murphy's)
                                  │
    Alpha ────┐                   │                   ┌──── Echo
    (Portable) │                  │                   │ (Portable)
               │                  │                   │
    Beta ──────┼─── Gamma ────────┼────────── Delta ──┤
    (Solar)    │   (Gateway)      │         (Gateway) │
               │   WiFi: Yes      │         WiFi: Yes │
               │   MQTT: Config   │         MQTT: Config
               │
    Area 1 Local Mesh          Bridge          Area 2 Local Mesh
      

Configuration breakdown:

  • Gamma and Delta: Gateway nodes with full MQTT Module configuration and WiFi
  • Alpha, Beta, Echo: Regular nodes without MQTT Module configuration
  • Message propagation depends on "OK to MQTT" settings:
    • If Alpha has "OK to MQTT" = true: Alpha's messages reach Echo via Gamma → MQTT → Delta
    • If Alpha has "OK to MQTT" = false: Alpha's messages only reach Beta and Gamma locally

Key insight: Only gateway nodes need MQTT Module configuration, but all nodes that want their messages to cross mesh boundaries need "OK to MQTT" enabled.


Get Involved

If you're interested in joining the ERSN Meshtastic Working Group:

  • Ask to join our email list by dropping a note to ersnnets@gmail.com
  • Share your location and device info to help us build a map of active nodes
  • Help test and document signal ranges, bridging behavior, and power setups
  • Stay tuned for events and updates

Together, we'll build a resilient, decentralized communication fabric for the mountains.